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1 files changed, 7120 insertions, 2811 deletions
diff --git a/contrib/groff/doc/groff.texinfo b/contrib/groff/doc/groff.texinfo index c8965c7..410a9d5 100644 --- a/contrib/groff/doc/groff.texinfo +++ b/contrib/groff/doc/groff.texinfo @@ -4,15 +4,43 @@ @c Please convert this manual with `texi2dvi -e groff.texinfo' due to a bug @c in texinfo regarding expansion of user-defined macros. @c +@c You need texinfo 4.2 or newer to format this document! +@c @c %**start of header (This is for running Texinfo on a region.) -@setfilename groff +@setfilename groff @settitle The GNU Troff Manual @setchapternewpage odd @footnotestyle separate @c %**end of header (This is for running Texinfo on a region.) +@smallbook + +@finalout + + +@copying +This manual documents GNU @code{troff} version 1.18. + +Copyright @copyright{} 1994-2000, 2001, 2002 Free Software Foundation, Inc. + +@quotation +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU Free Documentation License, Version 1.1 or +any later version published by the Free Software Foundation; with no +Invariant Sections, with the Front-Cover texts being `A GNU Manual,'' +and with the Back-Cover Texts as in (a) below. A copy of the +license is included in the section entitled `GNU Free Documentation +License.'' + +(a) The FSF's Back-Cover Text is: `You have freedom to copy and modify +this GNU Manual, like GNU software. Copies published by the Free +Software Foundation raise funds for GNU development.'' +@end quotation +@end copying + + @c We use the following indices: @c @c cindex: concepts @@ -24,7 +52,6 @@ @c tindex: environment variables @c maindex: macros @c stindex: strings -@c glindex: glyph names @c opindex: operators @c @c tindex and cindex are merged. @@ -33,7 +60,6 @@ @defcodeindex es @defcodeindex ma @defcodeindex st -@defcodeindex gl @defcodeindex op @syncodeindex tp cp @@ -53,16 +79,66 @@ @end tex +@c To assure correct HTML translation, some ugly hacks are necessary. +@c While processing a @def... request, the HTML translator looks at the +@c next line to decide whether it should start indentation or not. If +@c it is something starting with @def... (e.g. @deffnx), it doesn't. +@c So we must assure during macro expansion that a @def... is seen. +@c +@c The following macros have to be used: +@c +@c One item: +@c +@c @Def... +@c +@c Two items: +@c +@c @Def...List +@c @Def...ListEnd +@c +@c More than two: +@c +@c @Def...List +@c @Def...Item +@c @Def...Item +@c ... +@c @Def...ListEnd +@c +@c The definition block must end with +@c +@c @endDef... +@c +@c The above is valid for texinfo 4.0f. + + +@c a dummy macro to assure the `@def...' + +@macro defdummy +@end macro + + @c definition of requests @macro Defreq{name, arg} +@deffn Request @t{.\name\} \arg\ @rqindex \name\ +@end macro + +@macro DefreqList{name, arg} @deffn Request @t{.\name\} \arg\ +@defdummy +@rqindex \name\ @end macro -@macro Defreqx{name, arg} +@macro DefreqItem{name, arg} +@deffnx Request @t{.\name\} \arg\ +@defdummy @rqindex \name\ +@end macro + +@macro DefreqListEnd{name, arg} @deffnx Request @t{.\name\} \arg\ +@rqindex \name\ @end macro @macro endDefreq @@ -73,13 +149,25 @@ @c definition of escapes @macro Defesc{name, delimI, arg, delimII} +@deffn Escape @t{\name\\delimI\}@var{\arg\}@t{\delimII\} @esindex \name\ +@end macro + +@macro DefescList{name, delimI, arg, delimII} @deffn Escape @t{\name\\delimI\}@var{\arg\}@t{\delimII\} +@defdummy +@esindex \name\ @end macro -@macro Defescx{name, delimI, arg, delimII} +@macro DefescItem{name, delimI, arg, delimII} +@deffnx Escape @t{\name\\delimI\}@var{\arg\}@t{\delimII\} +@defdummy @esindex \name\ +@end macro + +@macro DefescListEnd{name, delimI, arg, delimII} @deffnx Escape @t{\name\\delimI\}@var{\arg\}@t{\delimII\} +@esindex \name\ @end macro @macro endDefesc @@ -90,13 +178,25 @@ @c definition of registers @macro Defreg{name} +@deffn Register @t{\\n[\name\]} @vindex \name\ +@end macro + +@macro DefregList{name} @deffn Register @t{\\n[\name\]} +@defdummy +@vindex \name\ @end macro -@macro Defregx{name} +@macro DefregItem{name} +@deffnx Register @t{\\n[\name\]} +@defdummy @vindex \name\ +@end macro + +@macro DefregListEnd{name} @deffnx Register @t{\\n[\name\]} +@vindex \name\ @end macro @macro endDefreg @@ -104,16 +204,57 @@ @end macro +@c definition of registers specific to macro packages, preprocessors, etc. + +@macro Defmpreg{name, package} +@deffn Register @t{\\n[\name\]} +@vindex \name\ @r{[}\package\@r{]} +@end macro + +@macro DefmpregList{name, package} +@deffn Register @t{\\n[\name\]} +@defdummy +@vindex \name\ @r{[}\package\@r{]} +@end macro + +@macro DefmpregItem{name, package} +@deffnx Register @t{\\n[\name\]} +@defdummy +@vindex \name\ @r{[}\package\@r{]} +@end macro + +@macro DefmpregListEnd{name, package} +@deffnx Register @t{\\n[\name\]} +@vindex \name\ @r{[}\package\@r{]} +@end macro + +@macro endDefmpreg +@end deffn +@end macro + + @c definition of macros -@macro Defmac{name, arg} -@maindex \name\ +@macro Defmac{name, arg, package} @defmac @t{.\name\} \arg\ +@maindex \name\ @r{[}\package\@r{]} +@end macro + +@macro DefmacList{name, arg, package} +@defmac @t{.\name\} \arg\ +@defdummy +@maindex \name\ @r{[}\package\@r{]} +@end macro + +@macro DefmacItem{name, arg, package} +@defmacx @t{.\name\} \arg\ +@defdummy +@maindex \name\ @r{[}\package\@r{]} @end macro -@macro Defmacx{name, arg} -@maindex \name\ +@macro DefmacListEnd{name, arg, package} @defmacx @t{.\name\} \arg\ +@maindex \name\ @r{[}\package\@r{]} @end macro @macro endDefmac @@ -123,14 +264,26 @@ @c definition of strings -@macro Defstr{name, arg} -@stindex \name\ -@deffn String @t{\name\} \arg\ +@macro Defstr{name, package} +@deffn String @t{\\*[\name\]} +@stindex \name\ @r{[}\package\@r{]} +@end macro + +@macro DefstrList{name, package} +@deffn String @t{\\*[\name\]} +@defdummy +@stindex \name\ @r{[}\package\@r{]} +@end macro + +@macro DefstrItem{name, package} +@deffnx String @t{\\*[\name\]} +@defdummy +@stindex \name\ @r{[}\package\@r{]} @end macro -@macro Defstrx{name, arg} -@stindex \name\ -@deffnx String @t{\name\} \arg\ +@macro DefstrListEnd{name, package} +@deffnx String @t{\\*[\name\]} +@stindex \name\ @r{[}\package\@r{]} @end macro @macro endDefstr @@ -151,15 +304,50 @@ @end macro +@c <text> + +@tex +\gdef\angles#1{\angleleft{}\r{#1}\angleright{}} +@end tex + +@macro angles{text} +<\text\> +@end macro + + +@c a <= sign + +@tex +\gdef\LE{\le} +@end tex + +@macro LE +<= +@end macro + + +@c due to a bug in texinfo 4.2, the spacing of `<' is bad in @item + +@tex +\gdef\LT{\string<} +@end tex + +@macro LT +< +@end macro + + @c We need special parentheses and brackets: @c @c . Real parentheses in @deffn produce an error while compiling with @c TeX @c . Real brackets use the wrong font in @deffn, overriding @t{}. @c +@c Since macros aren't expanded in @deffn during -E, the following +@c definitions are for non-TeX only. +@c @c This is true for texinfo 4.0. -@ifnottex @macro lparen ( @end macro @@ -172,147 +360,54 @@ @macro rbrack ] @end macro -@end ifnottex -@iftex -@macro lparen -@@lparen -@end macro -@macro rparen -@@rparen -@end macro -@macro lbrack -@@lbrack -@end macro -@macro rbrack -@@rbrack -@end macro -@end iftex - -@c Note: We say `Roman numerals' but `roman font'. +@tex +\gdef\gobblefirst#1#2{#2} +\gdef\putwordAppendix{\gobblefirst} +@end tex -@c XXX comment all examples +@c Note: We say `Roman numerals' but `roman font'. @dircategory Miscellaneous @direntry -* Groff: (groff). The GNU troff document formatting system. +* Groff: (groff). The GNU troff document formatting system. @end direntry -@smallbook - - -@iftex -@finalout -@end iftex - - -@ifinfo -This Info file documents GNU troff version 1.16. - -Published by the Free Software Foundation -59 Temple Place, Suite 330 -Boston, MA 02111-1307 USA - -Copyright (C) 1994-2000 Free Software Foundation, Inc. - -Permission is granted to make and distribute verbatim copies of this -manual provided the copyright notice and this permission notice are -preserved on all copies. - -@ignore -Permission is granted to process this file through TeX and print the -results, provided the printed document carries copying permission notice -identical to this one except for the removal of this paragraph (this -paragraph not being relevant to the printed manual). - -@end ignore -Permission is granted to copy and distribute modified versions of this -manual under the conditions for verbatim copying, provided that the -entire resulting derived work is distributed under the terms of a -permission notice identical to this one. - -Permission is granted to copy and distribute translations of this manual -into another language, under the above conditions for modified versions, -except that this permission notice may be stated in a translation -approved by the Foundation. - -Permission is granted to copy and distribute modified versions of this -manual under the conditions for verbatim copying, provided also that the -section entitled ``GNU General Public License'' is included exactly as -in the original, and provided that the entire resulting derived work is -distributed under the terms of a permission notice identical to this -one. - -Permission is granted to copy and distribute translations of this manual -into another language, under the above conditions for modified versions, -except that the section entitled ``GNU General Public License'' may be -included in a translation approved by the Free Software Foundation -instead of in the original English. -@end ifinfo - - @titlepage @title groff @subtitle The GNU implementation of @code{troff} -@subtitle Edition 1.16 -@subtitle Spring 2000 +@subtitle Edition 1.18 +@subtitle Spring 2002 @author by Trent A.@w{ }Fisher -@author and Werner Lemberg - -@c Include the Distribution inside the titlepage environment so -@c that headings are turned off. Headings on and off do not work. +@author and Werner Lemberg (@email{bug-groff@@gnu.org}) @page @vskip 0pt plus 1filll -Copyright @copyright@w{ }1994-2000 Free Software Foundation,@w{ }Inc. -@sp 2 -Version 1.16 of @code{groff}, @* -Spring 2000 -@sp 2 -Published by the Free Software Foundation @* -59 Temple Place, Suite 330 @* -Boston, MA 02111-1307 USA - - -Permission is granted to make and distribute verbatim copies of this -manual provided the copyright notice and this permission notice are -preserved on all copies. - -Permission is granted to copy and distribute modified versions of this -manual under the conditions for verbatim copying, provided also that the -section entitled ``GNU General Public License'' is included exactly as -in the original, and provided that the entire resulting derived work is -distributed under the terms of a permission notice identical to this -one. - -Permission is granted to copy and distribute translations of this manual -into another language, under the above conditions for modified versions, -except that the section entitled ``GNU General Public License'' may be -included in a translation approved by the Free Software Foundation -instead of in the original English. - -Cover art by Etienne Suvasa. +@insertcopying @end titlepage -@page - -@node Top, Copying, (dir), (dir) +@contents @ifinfo -This Info file documents groff version 1.16, the GNU implementation of -the troff typesetting system. +@node Top, Introduction, (dir), (dir) +@top GNU troff -This is an in-progress document; contributions, comments, or -contributions are welcome. Send them to bug-groff@@gnu.org. +@insertcopying @end ifinfo +@ifhtml +@node Top, Introduction, (dir), (dir) +@top GNU troff + +@insertcopying +@end ifhtml + @menu -* Copying:: * Introduction:: * Invoking groff:: * Tutorial for Macro Users:: @@ -322,6 +417,7 @@ contributions are welcome. Send them to bug-groff@@gnu.org. * Output Devices:: * File formats:: * Installation:: +* Copying This Manual:: * Request Index:: * Escape Index:: * Operator Index:: @@ -336,406 +432,10 @@ contributions are welcome. Send them to bug-groff@@gnu.org. -@node Copying, Introduction, Top, Top -@cindex copying -@unnumbered GNU GENERAL PUBLIC LICENSE -@center Version 2, June 1991 - -@display -Copyright @copyright{}@w{ }1989, 1991 Free Software Foundation, Inc. -59@w{ }Temple Place, Suite@w{ }330, Boston, MA@w{ }02111, USA - -Everyone is permitted to copy and distribute verbatim copies of this -license document, but changing it is not allowed. -@end display - -@unnumberedsec Preamble - -The licenses for most software are designed to take away your freedom to -share and change it. By contrast, the GNU General Public License is -intended to guarantee your freedom to share and change free software -- -to make sure the software is free for all its users. This General -Public License applies to most of the Free Software Foundation's -software and to any other program whose authors commit to using it. -(Some other Free Software Foundation software is covered by the GNU -Library General Public License instead.) You can apply it to your -programs, too. - -When we speak of free software, we are referring to freedom, not price. -Our General Public Licenses are designed to make sure that you have the -freedom to distribute copies of free software (and charge for this -service if you wish), that you receive source code or can get it if you -want it, that you can change the software or use pieces of it in new -free programs; and that you know you can do these things. - -To protect your rights, we need to make restrictions that forbid anyone -to deny you these rights or to ask you to surrender the rights. These -restrictions translate to certain responsibilities for you if you -distribute copies of the software, or if you modify it. - -For example, if you distribute copies of such a program, whether gratis -or for a fee, you must give the recipients all the rights that you have. -You must make sure that they, too, receive or can get the source code. -And you must show them these terms so they know their rights. - -We protect your rights with two steps: (1)@w{ }copyright the software, -and (2)@w{ }offer you this license which gives you legal permission to -copy, distribute and/or modify the software. - -Also, for each author's protection and ours, we want to make certain -that everyone understands that there is no warranty for this free -software. If the software is modified by someone else and passed on, we -want its recipients to know that what they have is not the original, so -that any problems introduced by others will not reflect on the original -authors' reputations. - -Finally, any free program is threatened constantly by software patents. -We wish to avoid the danger that redistributors of a free program will -individually obtain patent licenses, in effect making the program -proprietary. To prevent this, we have made it clear that any patent -must be licensed for everyone's free use or not licensed at all. - -The precise terms and conditions for copying, distribution and -modification follow. - -@iftex -@unnumberedsec TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION -@end iftex -@ifinfo -@center TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION -@end ifinfo - -@enumerate 0 -@item -This License applies to any program or other work which contains a -notice placed by the copyright holder saying it may be distributed under -the terms of this General Public License. The ``Program'', below, -refers to any such program or work, and a ``work based on the Program'' -means either the Program or any derivative work under copyright law: -that is to say, a work containing the Program or a portion of it, either -verbatim or with modifications and/or translated into another language. -(Hereinafter, translation is included without limitation in the term -``modification''.) Each licensee is addressed as ``you''. - -Activities other than copying, distribution and modification are not -covered by this License; they are outside its scope. The act of running -the Program is not restricted, and the output from the Program is -covered only if its contents constitute a work based on the Program -(independent of having been made by running the Program). Whether that -is true depends on what the Program does. - -@item -You may copy and distribute verbatim copies of the Program's source code -as you receive it, in any medium, provided that you conspicuously and -appropriately publish on each copy an appropriate copyright notice and -disclaimer of warranty; keep intact all the notices that refer to this -License and to the absence of any warranty; and give any other -recipients of the Program a copy of this License along with the Program. - -You may charge a fee for the physical act of transferring a copy, and -you may at your option offer warranty protection in exchange for a fee. - -@item -You may modify your copy or copies of the Program or any portion of it, -thus forming a work based on the Program, and copy and distribute such -modifications or work under the terms of Section@w{ }1 above, provided -that you also meet all of these conditions: - -@enumerate a -@item -You must cause the modified files to carry prominent notices stating -that you changed the files and the date of any change. - -@item -You must cause any work that you distribute or publish, that in whole or -in part contains or is derived from the Program or any part thereof, to -be licensed as a whole at no charge to all third parties under the terms -of this License. - -@item -If the modified program normally reads commands interactively when run, -you must cause it, when started running for such interactive use in the -most ordinary way, to print or display an announcement including an -appropriate copyright notice and a notice that there is no warranty (or -else, saying that you provide a warranty) and that users may -redistribute the program under these conditions, and telling the user -how to view a copy of this License. (Exception: if the Program itself -is interactive but does not normally print such an announcement, your -work based on the Program is not required to print an announcement.) -@end enumerate - -These requirements apply to the modified work as a whole. If -identifiable sections of that work are not derived from the Program, and -can be reasonably considered independent and separate works in -themselves, then this License, and its terms, do not apply to those -sections when you distribute them as separate works. But when you -distribute the same sections as part of a whole which is a work based on -the Program, the distribution of the whole must be on the terms of this -License, whose permissions for other licensees extend to the entire -whole, and thus to each and every part regardless of who wrote it. - -Thus, it is not the intent of this section to claim rights or contest -your rights to work written entirely by you; rather, the intent is to -exercise the right to control the distribution of derivative or -collective works based on the Program. - -In addition, mere aggregation of another work not based on the Program -with the Program (or with a work based on the Program) on a volume of a -storage or distribution medium does not bring the other work under the -scope of this License. - -@item -You may copy and distribute the Program (or a work based on it, under -Section@w{ }2) in object code or executable form under the terms of -Sections@w{ }1 and@w{ }2 above provided that you also do one of the -following: - -@enumerate a -@item -Accompany it with the complete corresponding machine-readable source -code, which must be distributed under the terms of Sections@w{ }1 and@w{ -}2 above on a medium customarily used for software interchange; or, - -@item -Accompany it with a written offer, valid for at least three years, to -give any third party, for a charge no more than your cost of physically -performing source distribution, a complete machine-readable copy of the -corresponding source code, to be distributed under the terms of -Sections@w{ }1 and@w{ }2 above on a medium customarily used for software -interchange; or, - -@item -Accompany it with the information you received as to the offer to -distribute corresponding source code. (This alternative is allowed only -for noncommercial distribution and only if you received the program in -object code or executable form with such an offer, in accord with -Subsection@w{ }b above.) -@end enumerate - -The source code for a work means the preferred form of the work for -making modifications to it. For an executable work, complete source -code means all the source code for all modules it contains, plus any -associated interface definition files, plus the scripts used to control -compilation and installation of the executable. However, as a special -exception, the source code distributed need not include anything that is -normally distributed (in either source or binary form) with the major -components (compiler, kernel, and so on) of the operating system on -which the executable runs, unless that component itself accompanies the -executable. - -If distribution of executable or object code is made by offering access -to copy from a designated place, then offering equivalent access to copy -the source code from the same place counts as distribution of the source -code, even though third parties are not compelled to copy the source -along with the object code. - -@item -You may not copy, modify, sublicense, or distribute the Program except -as expressly provided under this License. Any attempt otherwise to -copy, modify, sublicense or distribute the Program is void, and will -automatically terminate your rights under this License. However, -parties who have received copies, or rights, from you under this License -will not have their licenses terminated so long as such parties remain -in full compliance. - -@item -You are not required to accept this License, since you have not signed -it. However, nothing else grants you permission to modify or distribute -the Program or its derivative works. These actions are prohibited by -law if you do not accept this License. Therefore, by modifying or -distributing the Program (or any work based on the Program), you -indicate your acceptance of this License to do so, and all its terms and -conditions for copying, distributing or modifying the Program or works -based on it. - -@item -Each time you redistribute the Program (or any work based on the -Program), the recipient automatically receives a license from the -original licensor to copy, distribute or modify the Program subject to -these terms and conditions. You may not impose any further restrictions -on the recipients' exercise of the rights granted herein. You are not -responsible for enforcing compliance by third parties to this License. - -@item -If, as a consequence of a court judgment or allegation of patent -infringement or for any other reason (not limited to patent issues), -conditions are imposed on you (whether by court order, agreement or -otherwise) that contradict the conditions of this License, they do not -excuse you from the conditions of this License. If you cannot -distribute so as to satisfy simultaneously your obligations under this -License and any other pertinent obligations, then as a consequence you -may not distribute the Program at all. For example, if a patent license -would not permit royalty-free redistribution of the Program by all those -who receive copies directly or indirectly through you, then the only way -you could satisfy both it and this License would be to refrain entirely -from distribution of the Program. - -If any portion of this section is held invalid or unenforceable under -any particular circumstance, the balance of the section is intended to -apply and the section as a whole is intended to apply in other -circumstances. - -It is not the purpose of this section to induce you to infringe any -patents or other property right claims or to contest validity of any -such claims; this section has the sole purpose of protecting the -integrity of the free software distribution system, which is implemented -by public license practices. Many people have made generous -contributions to the wide range of software distributed through that -system in reliance on consistent application of that system; it is up to -the author/donor to decide if he or she is willing to distribute -software through any other system and a licensee cannot impose that -choice. - -This section is intended to make thoroughly clear what is believed to be -a consequence of the rest of this License. - -@item -If the distribution and/or use of the Program is restricted in certain -countries either by patents or by copyrighted interfaces, the original -copyright holder who places the Program under this License may add an -explicit geographical distribution limitation excluding those countries, -so that distribution is permitted only in or among countries not thus -excluded. In such case, this License incorporates the limitation as if -written in the body of this License. - -@item -The Free Software Foundation may publish revised and/or new versions of -the General Public License from time to time. Such new versions will be -similar in spirit to the present version, but may differ in detail to -address new problems or concerns. - -Each version is given a distinguishing version number. If the Program -specifies a version number of this License which applies to it and ``any -later version'', you have the option of following the terms and -conditions either of that version or of any later version published by -the Free Software Foundation. If the Program does not specify a version -number of this License, you may choose any version ever published by the -Free Software Foundation. - -@item -If you wish to incorporate parts of the Program into other free programs -whose distribution conditions are different, write to the author to ask -for permission. For software which is copyrighted by the Free Software -Foundation, write to the Free Software Foundation; we sometimes make -exceptions for this. Our decision will be guided by the two goals of -preserving the free status of all derivatives of our free software and -of promoting the sharing and reuse of software generally. - -@iftex -@heading NO WARRANTY -@end iftex -@ifinfo -@center NO WARRANTY -@end ifinfo - -@item -BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR -THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW@. EXCEPT WHEN -OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES -PROVIDE THE PROGRAM ``AS IS'' WITHOUT WARRANTY OF ANY KIND, EITHER -EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED -WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE@. -THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH -YOU@. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL -NECESSARY SERVICING, REPAIR OR CORRECTION. - -@item -IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING -WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR -REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR -DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL -DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM -(INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED -INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF -THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR -OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. -@end enumerate - -@iftex -@heading END OF TERMS AND CONDITIONS -@end iftex -@ifinfo -@center END OF TERMS AND CONDITIONS -@end ifinfo - - -@page -@unnumberedsec How to Apply These Terms to Your New Programs - -If you develop a new program, and you want it to be of the greatest -possible use to the public, the best way to achieve this is to make it -free software which everyone can redistribute and change under these -terms. - -To do so, attach the following notices to the program. It is safest to -attach them to the start of each source file to most effectively convey -the exclusion of warranty; and each file should have at least the -``copyright'' line and a pointer to where the full notice is found. - -@smallexample -@var{one line to give the program's name and an idea of what it does.} -Copyright (C) 19@var{yy} @var{name of author} - -This program is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2 of the License, or (at -your option) any later version. - -This program is distributed in the hope that it will be useful, but -WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE@. See the GNU -General Public License for more details. - -You should have received a copy of the GNU General Public License -along with this program; if not, write to the Free Software -Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA. -@end smallexample - -Also add information on how to contact you by electronic and paper mail. - -If the program is interactive, make it output a short notice like this -when it starts in an interactive mode: - -@smallexample -Gnomovision version 69, Copyright (C) 19@var{yy} @var{name of author} -Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type -`show w'. This is free software, and you are welcome to redistribute -it under certain conditions; type `show c' for details. -@end smallexample - -The hypothetical commands @samp{show@w{ }w} and @samp{show@w{ }c} should -show the appropriate parts of the General Public License. Of course, -the commands you use may be called something other than @samp{show@w{ -}w} and @samp{show@w{ }c}; they could even be mouse-clicks or menu items --- whatever suits your program. - -You should also get your employer (if you work as a programmer) or your -school, if any, to sign a ``copyright disclaimer'' for the program, if -necessary. Here is a sample; alter the names: - -@smallexample -@group -Yoyodyne, Inc., hereby disclaims all copyright interest -in the program `Gnomovision' (which makes passes at compilers) -written by James Hacker. - -@var{signature of Ty Coon}, 1 April 1989 -Ty Coon, President of Vice -@end group -@end smallexample - -This General Public License does not permit incorporating your program -into proprietary programs. If your program is a subroutine library, you -may consider it more useful to permit linking proprietary applications -with the library. If this is what you want to do, use the GNU Library -General Public License instead of this License. - - - @c ===================================================================== @c ===================================================================== -@node Introduction, Invoking groff, Copying, Top +@node Introduction, Invoking groff, Top, Top @chapter Introduction @cindex introduction @@ -811,8 +511,8 @@ impossible to accomplish complex actions.'' --Doug Gwyn (22/Jun/91 in @section History @cindex history -@cindex @code{runoff} -@cindex @code{rf} +@cindex @code{runoff}, the program +@cindex @code{rf}, the program @code{troff} can trace its origins back to a formatting program called @code{runoff}, written by J.@w{ }E.@w{ }Saltzer, which ran on MIT's CTSS operating system in the mid-sixties. This name came from the common @@ -823,16 +523,16 @@ of @code{runoff}). It was rewritten as @code{rf} for the @w{PDP-7} McIllroy rewrote an extended and simplified version of @code{roff} in the @acronym{BCPL} programming language. -@cindex @code{roff} +@cindex @code{roff}, the program The first version of @acronym{UNIX} was developed on a @w{PDP-7} which was sitting around Bell Labs. In 1971 the developers wanted to get a @w{PDP-11} for further work on the operating system. In order to justify the cost for this system, they proposed that they would -implement a document formatting system for the AT&T patents division. -This first formatting program was a reimplementation of McIllroy's -@code{roff}, written by J.@w{ }F.@w{ }Ossanna. +implement a document formatting system for the @acronym{AT&T} patents +division. This first formatting program was a reimplementation of +McIllroy's @code{roff}, written by J.@w{ }F.@w{ }Ossanna. -@cindex @code{nroff} +@cindex @code{nroff}, the program When they needed a more flexible language, a new version of @code{roff} called @code{nroff} (``Newer @code{roff}'') was written. It had a much more complicated syntax, but provided the basis for all future versions. @@ -866,12 +566,12 @@ He rewrote it in C, although it was now 7000@w{ }lines of uncommented code and still dependent on the CAT. As the CAT became less common, and was no longer supported by the manufacturer, the need to make it support other devices became a priority. However, before this could be done, -Ossanna was killed in an auto accident. +Ossanna was killed in a car accident. @pindex ditroff -@cindex @code{ditroff} +@cindex @code{ditroff}, the program So, Brian Kernighan took on the task of rewriting @code{troff}. The -newly rewritten version produced a device independent code which was +newly rewritten version produced device independent code which was very easy for postprocessors to read and translate to the appropriate printer codes. Also, this new version of @code{troff} (called @code{ditroff} for ``device independent @code{troff}'') had several @@ -897,7 +597,7 @@ The @code{soelim}, @code{pic}, @code{tbl}, and @code{eqn} preprocessors. @item Postprocessors for character devices, @sc{PostScript}, @TeX{} DVI, and -X@w{ }windows. GNU @code{troff} also eliminated the need for a +X@w{ }Windows. GNU @code{troff} also eliminated the need for a separate @code{nroff} program with a postprocessor which would produce @acronym{ASCII} output. @@ -947,10 +647,10 @@ hyphenation page control @item -font and character size control +font and glyph size control @item -vertical spacing (i.e.@: double spacing) +vertical spacing (e.g.@: double-spacing) @item line length and indenting @@ -1020,15 +720,15 @@ common (and the ones described in this manual) are @file{man}, Although @code{groff} provides most functions needed to format a document, some operations would be unwieldy (e.g.@: to draw pictures). -Therefore, programs called preprocessors were written which understand -their own language and produce the necessary @code{groff} operations. -These preprocessors are able to differentiate their own input from the -rest of the document via markers. +Therefore, programs called @dfn{preprocessors} were written which +understand their own language and produce the necessary @code{groff} +operations. These preprocessors are able to differentiate their own +input from the rest of the document via markers. To use a preprocessor, @acronym{UNIX} pipes are used to feed the output from the preprocessor into @code{groff}. Any number of preprocessors may be used on a given document; in this case, the preprocessors are -linked together into one pipeline. However, in @code{groff}, the user +linked together into one pipeline. However, with @code{groff}, the user does not need to construct the pipe, but only tell @code{groff} what preprocessors to use. @@ -1078,6 +778,7 @@ The section on the @file{man} macro package is partly based on Susan@w{ }G.@: Kleinmann's @file{groff_man} manual page written for the Debian GNU/Linux system. +Larry Kollar contributed the section in the @file{ms} macro package. @@ -1096,15 +797,24 @@ the preprocessors, @code{gtroff} and the postprocessor. It has become a tradition that GNU programs get the prefix @samp{g} to distinguish it from its original counterparts provided by the host (see @ref{Environment}, for more details). Thus, for example, @code{geqn} is -GNU @code{eqn}. On operating systems like Linux or the Hurd, which -don't contain proprietary software, and on MS-DOS/MS-Windows, where -@code{troff} and associated programs are not available at all, this -prefix is omitted since GNU @code{troff} is the only used incarnation of -@code{troff}. Exception: @code{groff} is never replaced by @code{roff}. +GNU @code{eqn}. On operating systems like GNU/Linux or the Hurd, which +don't contain proprietary versions of @code{troff}, and on +MS-DOS/MS-Windows, where @code{troff} and associated programs are not +available at all, this prefix is omitted since GNU @code{troff} is the +only used incarnation of @code{troff}. Exception: @samp{groff} is never +replaced by @samp{roff}. + +In this document, we consequently say @samp{gtroff} when talking about +the GNU @code{troff} program. All other implementations of @code{troff} +are called @acronym{AT&T} @code{troff} which is the common origin of +all @code{troff} derivates (with more or less compatible changes). +Similarly, we say @samp{gpic}, @samp{geqn}, etc. @menu * Groff Options:: * Environment:: +* Macro Directories:: +* Font Directories:: * Invocation Examples:: @end menu @@ -1142,7 +852,7 @@ grolbp}, and @ref{Invoking gxditview}. The command line format for @code{groff} is: @Example -groff [ -abeghilpstvzCEGNRSUVXZ ] [ -F@var{dir} ] [ -m@var{name} ] +groff [ -abceghilpstvzCEGNRSUVXZ ] [ -F@var{dir} ] [ -m@var{name} ] [ -T@var{def} ] [ -f@var{fam} ] [ -w@var{name} ] [ -W@var{name} ] [ -M@var{dir} ] [ -d@var{cs} ] [ -r@var{cn} ] [ -n@var{num} ] [ -o@var{list} ] [ -P@var{arg} ] [ -L@var{arg} ] [ -I@var{dir} ] @@ -1152,7 +862,7 @@ groff [ -abeghilpstvzCEGNRSUVXZ ] [ -F@var{dir} ] [ -m@var{name} ] The command line format for @code{gtroff} is as follows. @Example -gtroff [ -abivzCERU ] [ -w@var{name} ] [ -W@var{name} ] [ -d@var{cs} ] +gtroff [ -abcivzCERU ] [ -w@var{name} ] [ -W@var{name} ] [ -d@var{cs} ] [ -f@var{fam} ] [ -m@var{name} ] [ -n@var{num} ] [ -o@var{list} ] [ -r@var{cn} ] [ -T@var{name} ] [ -F@var{dir} ] [ -M@var{dir} ] [ @var{files}@dots{} ] @@ -1162,8 +872,8 @@ gtroff [ -abivzCERU ] [ -w@var{name} ] [ -W@var{name} ] [ -d@var{cs} ] Obviously, many of the options to @code{groff} are actually passed on to @code{gtroff}. -Options without an argument can be grouped behind a single @option{-}. -A filename of @file{-} denotes the standard input. It is possible to +Options without an argument can be grouped behind a single@w{ }@option{-}. +A filename of@w{ }@file{-} denotes the standard input. It is possible to have whitespace between an option and its parameter. The @code{grog} command can be used to guess the correct @code{groff} @@ -1194,6 +904,9 @@ Preprocess with @code{gpic}. @item -s Preprocess with @code{gsoelim}. +@item -c +Suppress color output. + @item -R Preprocess with @code{grefer}. No mechanism is provided for passing arguments to @code{grefer} because most @code{grefer} options have @@ -1232,9 +945,9 @@ ignored. @item -L@var{arg} Pass @var{arg} to the spooler. Each argument should be passed with a -separate @option{-L} option. Note that @code{groff} does not prepend a -@samp{-} to @var{arg} before passing it to the postprocessor. If the -@code{print} keyword in the device description file is missing, +separate @option{-L} option. Note that @code{groff} does not prepend +a @samp{-} to @var{arg} before passing it to the postprocessor. +If the @code{print} keyword in the device description file is missing, @option{-L} is ignored. @item -T@var{dev} @@ -1252,29 +965,46 @@ For @TeX{} DVI format. @item X75 For a 75@dmn{dpi} X11 previewer. +@item X75-12 +For a 75@dmn{dpi} X11 previewer with a 12@dmn{pt} base font in the +document. + @item X100 For a 100@dmn{dpi} X11 previewer. +@item X100-12 +For a 100@dmn{dpi} X11 previewer with a 12@dmn{pt} base font in the +document. + @item ascii -For typewriter-like devices. +@cindex encoding, @acronym{ASCII} +@cindex @acronym{ASCII}, encoding +For typewriter-like devices using the (7-bit) @acronym{ASCII} +character set. @item latin1 +@cindex encoding, latin-1 +@cindex latin-1, encoding For typewriter-like devices that support the @w{Latin-1} (@w{ISO 8859-1}) character set. @item utf8 +@cindex encoding, utf-8 +@cindex utf-8, encoding For typewriter-like devices which use the Unicode (@w{ISO 10646}) character set with @w{UTF-8} encoding. @item cp1047 @cindex @acronym{EBCDIC} encoding +@cindex encoding, @acronym{EBCDIC} +@cindex encoding, cp1047 @cindex cp1047 @cindex IBM cp1047 For typewriter-like devices which use the @acronym{EBCDIC} encoding IBM cp1047. @item lj4 -For an HP LaserJet4-compatible (or other PCL5-compatible) printer. +For HP LaserJet4-compatible (or other PCL5-compatible) printers. @item lbp For Canon @acronym{CAPSL} printers (@w{LBP-4} and @w{LBP-8} series laser @@ -1282,15 +1012,15 @@ printers). @pindex pre-grohtml @pindex post-grohtml -@cindex @code{grohtml} +@cindex @code{grohtml}, the program @item html To produce @acronym{HTML} output. Note that the @acronym{HTML} driver consists of two parts, a preprocessor (@code{pre-grohtml}) and a postprocessor (@code{post-grohtml}). @end table -@vindex .T -@stindex .T +@cindex output device name string register (@code{.T}) +@cindex output device usage number register (@code{.T}) The predefined @code{gtroff} string register @code{.T} contains the current output device; the read-only number register @code{.T} is set to@w{ }1 if this option is used (which is always true if @code{groff} is @@ -1315,15 +1045,25 @@ Don't allow newlines with @code{eqn} delimiters. This is the same as the @option{-N} option in @code{geqn}. @item -S +@cindex @code{open} request, and safer mode +@cindex @code{opena} request, and safer mode +@cindex @code{pso} request, and safer mode +@cindex @code{sy} request, and safer mode +@cindex @code{pi} request, and safer mode +@cindex safer mode +@cindex mode, safer Safer mode. Pass the @option{-S} option to @code{gpic} and disable the @code{open}, @code{opena}, @code{pso}, @code{sy}, and @code{pi} requests. For security reasons, this is enabled by default. @item -U -Unsafe mode. Reverts to the old unsafe behaviour. +@cindex mode, unsafe +@cindex unsafe mode +Unsafe mode. This enables the @code{open}, @code{opena}, @code{pso}, +@code{sy}, and @code{pi} requests. @item -a -@vindex .A +@cindex @acronym{ASCII} approximation output register (@code{.A}) Generate an @acronym{ASCII} approximation of the typeset output. The read-only register @code{.A} is then set to@w{ }1. @xref{Built-in Registers}. A typical example is @@ -1359,13 +1099,13 @@ Inhibit all error messages. @item -C Enable compatibility mode. @xref{Implementation Differences}, for the -list of incompatibilities between @code{groff} and traditional Unix +list of incompatibilities between @code{groff} and @acronym{AT&T} @code{troff}. -@item -d@var{cs} -@itemx -d@var{name}=s -Define @var{c} or @var{name} to be a string @var{s}. @var{c} must be a -one-letter name; @var{name} can be of arbitrary length. All string +@item -d@var{c}@var{s} +@itemx -d@var{name}=@var{s} +Define @var{c} or @var{name} to be a string@w{ }@var{s}. @var{c}@w{ }must +be a one-letter name; @var{name} can be of arbitrary length. All string assignments happen before loading any macro file (including the start-up file). @@ -1375,20 +1115,18 @@ Use @var{fam} as the default font family. @xref{Font Families}. @item -m@var{name} Read in the file @file{@var{name}.tmac}. Normally @code{groff} searches for this in its macro directories. If it isn't found, it tries -@file{tmac.@var{name}} (and searches in the same directories). - -@c XXX document local and system macro dirs +@file{tmac.@var{name}} (searching in the same directories). @item -n@var{num} Number the first page @var{num}. @item -o@var{list} -@vindex .P +@cindex print current page register (@code{.P}) Output only pages in @var{list}, which is a comma-separated list of page -ranges; @samp{@var{n}} means print page @var{n}, @samp{@var{m}-@var{n}} -means print every page between @var{m} and @var{n}, @samp{-@var{n}} -means print every page up to @var{n}, @samp{@var{n}-} means print every -page beginning with @var{n}. @code{gtroff} exits after printing the +ranges; @samp{@var{n}} means print page@w{ }@var{n}, @samp{@var{m}-@var{n}} +means print every page between @var{m} and@w{ }@var{n}, @samp{-@var{n}} +means print every page up to@w{ }@var{n}, @samp{@var{n}-} means print every +page beginning with@w{ }@var{n}. @code{gtroff} exits after printing the last page in the list. All the ranges are inclusive on both ends. Within @code{gtroff}, this information can be extracted with the @@ -1398,22 +1136,24 @@ If your document restarts page numbering at the beginning of each chapter, then @code{gtroff} prints the specified page range for each chapter. -@item -r@var{cn} +@item -r@var{c}@var{n} @itemx -r@var{name}=@var{n} -Set number register @var{c} or @var{name} to the value @var{n}. @var{c} -must be a one-letter name; @var{name} can be of arbitrary length. -@var{n} can be any @code{gtroff} numeric expression. All register -assignments happen before loading any macro file (including the start-up -file). +Set number register@w{ }@var{c} or @var{name} to the value@w{ }@var{n}. +@var{c}@w{ }must be a one-letter name; @var{name} can be of arbitrary +length. @var{n}@w{ }can be any @code{gtroff} numeric expression. All +register assignments happen before loading any macro file (including +the start-up file). @item -F@var{dir} Search @file{@var{dir}} for subdirectories @file{dev@var{name}} (@var{name} is the name of the device), for the @file{DESC} file, and -for font files before looking in the standard directories. +for font files before looking in the standard directories (@pxref{Font +Directories}). This option is passed to all pre- and postprocessors +using the @env{GROFF_FONT_PATH} environment variable. @item -M@var{dir} Search directory @file{@var{dir}} for macro files before the standard -directories. +directories (@pxref{Macro Directories}). @item -I@var{dir} This option is as described in @ref{gsoelim}. It implies the @@ -1423,7 +1163,7 @@ This option is as described in @ref{gsoelim}. It implies the @c ===================================================================== -@node Environment, Invocation Examples, Groff Options, Invoking groff +@node Environment, Macro Directories, Groff Options, Invoking groff @section Environment @cindex environment variables @cindex variables in environment @@ -1433,40 +1173,42 @@ not within @code{gtroff}) which can modify the behavior of @code{groff}. @table @code @item GROFF_COMMAND_PREFIX -@tindex GROFF_COMMAND_PREFIX, environment variable -If this is set to @var{X}, then @code{groff} runs @code{@var{X}troff} +@tindex GROFF_COMMAND_PREFIX@r{, environment variable} +@cindex command prefix +@cindex prefix, for commands +If this is set to@w{ }@var{X}, then @code{groff} runs @code{@var{X}troff} instead of @code{gtroff}. This also applies to @code{tbl}, @code{pic}, @code{eqn}, @code{grn}, @code{refer}, and @code{soelim}. It does not apply to @code{grops}, @code{grodvi}, @code{grotty}, @code{pre-grohtml}, @code{post-grohtml}, @code{grolj4}, and @code{gxditview}. -@c XXX document default values +The default command prefix is determined during the installation process. +If a non-GNU troff system is found, prefix @samp{g} is used, none +otherwise. @item GROFF_TMAC_PATH -@tindex GROFF_TMAC_PATH, environment variable +@tindex GROFF_TMAC_PATH@r{, environment variable} A colon-separated list of directories in which to search for macro files -(before the default directories are tried). - -@c XXX document local and system macro dirs +(before the default directories are tried). @xref{Macro Directories}. @item GROFF_TYPESETTER -@tindex GROFF_TYPESETTER, environment variable +@tindex GROFF_TYPESETTER@r{, environment variable} The default output device. @item GROFF_FONT_PATH -@tindex GROFF_FONT_PATH, environment variable +@tindex GROFF_FONT_PATH@r{, environment variable} A colon-separated list of directories in which to search for the @code{dev}@var{name} directory (before the default directories are -tried). +tried). @xref{Font Directories}. @item GROFF_BIN_PATH -@tindex GROFF_BIN_PATH, environment variable +@tindex GROFF_BIN_PATH@r{, environment variable} This search path, followed by @code{PATH}, is used for commands executed by @code{groff}. @item GROFF_TMPDIR -@tindex GROFF_TMPDIR, environment variable -@tindex TMPDIR, environment variable +@tindex GROFF_TMPDIR@r{, environment variable} +@tindex TMPDIR@r{, environment variable} The directory in which @code{groff} creates temporary files. If this is not set and @env{TMPDIR} is set, temporary files are created in that directory. Otherwise temporary files are created in a system-dependent @@ -1482,7 +1224,137 @@ above. @c ===================================================================== -@node Invocation Examples, , Environment, Invoking groff +@node Macro Directories, Font Directories, Environment, Invoking groff +@section Macro Directories +@cindex macro directories +@cindex directories for macros +@cindex searching macros +@cindex macros, searching + +All macro file names must be named @code{@var{name}.tmac} or +@code{tmac.@var{name}} to make the @option{-m@var{name}} command line +option work. The @code{mso} request doesn't have this restriction; any +file name can be used, and @code{gtroff} won't try to append or prepend +the @samp{tmac} string. + +@cindex tmac, directory +@cindex directory, for tmac files +@cindex tmac, path +@cindex path, for tmac files +@cindex searching macro files +@cindex macro files, searching +@cindex files, macro, searching +Macro files are kept in the @dfn{tmac directories}, all of which +constitute the @dfn{tmac path}. The elements of the search path for +macro files are (in that order): + +@itemize @bullet +@item +The directories specified with @code{gtroff}'s or @code{groff}'s +@option{-M} command line option. + +@item +@tindex GROFF_TMAC_PATH@r{, environment variable} +The directories given in the @env{GROFF_TMAC_PATH} environment +variable. + +@item +@cindex safer mode +@cindex mode, safer +@cindex unsafe mode +@cindex mode, unsafe +@cindex current directory +@cindex directory, current +The current directory (only if in unsafe mode using the @option{-U} +command line switch). + +@item +@cindex home directory +@cindex directory, home +The home directory. + +@item +@cindex site-specific directory +@cindex directory, site-specific +@cindex platform-specific directory +@cindex directory, platform-specific +A platform-dependent directory, a site-specific (platform-independent) +directory, and the main tmac directory; the default locations are + +@Example +/usr/local/lib/groff/site-tmac +/usr/local/share/groff/site-tmac +/usr/local/share/groff/1.18/tmac +@endExample + +@noindent +assuming that the version of @code{groff} is 1.18, and the installation +prefix was @file{/usr/local}. It is possible to fine-tune those +directories during the installation process. +@end itemize + + +@c ===================================================================== + +@node Font Directories, Invocation Examples, Macro Directories, Invoking groff +@section Font Directories +@cindex font directories +@cindex directories for fonts +@cindex searching fonts +@cindex fonts, searching + +Basically, there is no restriction how font files for @code{groff} are +named and how long font names are; however, to make the font family +mechanism work (@pxref{Font Families}), fonts within a family should +start with the family name, followed by the shape. For example, the +Times family uses @samp{T} for the family name and @samp{R}, @samp{B}, +@samp{I}, and @samp{BI} to indicate the shapes `roman', `bold', +`italic', and `bold italic', respectively. Thus the final font names +are @samp{TR}, @samp{TB}, @samp{TI}, and @samp{TBI}. + +@cindex font path +@cindex path, for font files +All font files are kept in the @dfn{font directories} which constitute +the @dfn{font path}. The file search functions will always append the +directory @code{dev}@var{name}, where @var{name} is the name of the +output device. Assuming, say, DVI output, and @file{/foo/bar} as a +font directory, the font files for @code{grodvi} must be in +@file{/foo/bar/devdvi}. + +The elements of the search path for font files are (in that order): + +@itemize @bullet +@item +The directories specified with @code{gtroff}'s or @code{groff}'s +@option{-F} command line option. All device drivers and some +preprocessors also have this option. + +@item +@tindex GROFF_FONT_PATH@r{, environment variable} +The directories given in the @env{GROFF_FONT_PATH} environment +variable. + +@item +@cindex site-specific directory +@cindex directory, site-specific +A site-specific directory and the main font directory; the default +locations are + +@Example +/usr/local/share/groff/site-font +/usr/local/share/groff/1.18/font +@endExample + +@noindent +assuming that the version of @code{groff} is 1.18, and the installation +prefix was @file{/usr/local}. It is possible to fine-tune those +directories during the installation process. +@end itemize + + +@c ===================================================================== + +@node Invocation Examples, , Font Directories, Invoking groff @section Invocation Examples @cindex invocation examples @cindex examples of invocation @@ -1548,16 +1420,16 @@ double-sided printing -- don't produce any output. and/or macro packages are required for formatting them, and prints the @code{groff} command including those options on the standard output. It generates one or more of the options @option{-e}, @option{-man}, -@option{-me}, @option{-mm}, @option{-ms}, @option{-mdoc}, +@option{-me}, @option{-mm}, @option{-mom}, @option{-ms}, @option{-mdoc}, @option{-mdoc-old}, @option{-p}, @option{-R}, @option{-g}, @option{-G}, @option{-s}, and @option{-t}. -A special file name @file{-} refers to the standard input. Specifying +A special file name@w{ }@file{-} refers to the standard input. Specifying no files also means to read the standard input. Any specified options are included in the printed command. No space is allowed between options and their arguments. The only options recognized are @option{-C} (which is also passed on) to enable compatibility mode, and -@option{-v} (if it is the only parameter) to print the version number. +@option{-v} to print the version number and exit. For example, @@ -1654,7 +1526,7 @@ for all good men to come to the aid of their party. Four score and seven -years ago,... +years ago, etc. @endExample @noindent @@ -1662,7 +1534,7 @@ is read, packed onto output lines, and justified to produce: @quotation Now is the time for all good men to come to the aid of their party. -Four score and seven years ago,... +Four score and seven years ago, etc. @end quotation @cindex break @@ -1707,24 +1579,25 @@ hyphens out and join a word back together. Also, words such as can occur where not wanted, such as ``@w{mother- in}-law''. @end itemize -@rqindex ls -@cindex double spacing +@cindex double-spacing (@code{ls}) @cindex spacing -@code{gtroff} double spaces output text automatically if you use the -request @w{@samp{.ls 2}}. Reactivate single spaced mode by typing -@w{@samp{.ls 1}}. +@code{gtroff} double-spaces output text automatically if you use the +request @w{@samp{.ls 2}}. Reactivate single-spaced mode by typing +@w{@samp{.ls 1}}.@footnote{If you need finer granularity of the +vertical space, use the @code{pvs} request (@pxref{Changing Type +Sizes}).} A number of requests allow to change the way the output looks, sometimes called the @dfn{layout} of the output page. Most of these -requests adjust the placing of @dfn{white space} (blank lines or +requests adjust the placing of @dfn{whitespace} (blank lines or spaces). -@cindex new page -The @samp{.bp} request starts a new page, causing a line break. +@cindex new page (@code{bp}) +The @code{bp} request starts a new page, causing a line break. -@cindex blank line -@cindex empty line -@cindex line, empty +@cindex blank line (@code{sp}) +@cindex empty line (@code{sp}) +@cindex line, empty (@code{sp}) The request @w{@samp{.sp @var{N}}} leaves @var{N}@w{ }lines of blank space. @var{N}@w{ }can be omitted (meaning skip a single line) or can be of the form @var{N}i (for @var{N}@w{ }inches) or @var{N}c (for @@ -1741,9 +1614,8 @@ leaves one and a half inches of space, followed by the line ``My thoughts on the subject'', followed by a single blank line (more measurement units are available, see @ref{Measurements}). -@rqindex ce -@cindex centering lines -@cindex lines, centering +@cindex centering lines (@code{ce}) +@cindex lines, centering (@code{ce}) Text lines can be centered by using the @code{ce} request. The line after @code{ce} is centered (horizontally) on the page. To center more than one line, use @w{@samp{.ce @var{N}}} (where @var{N} is the number @@ -1760,9 +1632,8 @@ lines to center The @w{@samp{.ce 0}} request tells @code{groff} to center zero more lines, in other words, stop centering. -@rqindex br -@cindex line break -@cindex break +@cindex line break (@code{br}) +@cindex break (@code{br}) All of these requests cause a break; that is, they always start a new line. To start a new line without performing any other action, use @code{br}. @@ -1823,24 +1694,28 @@ sacred to be touched. And there are also indented paragraphs which begin with a tag or label at the margin and the remaining text indented. -@example -@group +@Example one This is the first paragraph. Notice how the first line of the resulting paragraph lines up with the other lines in the paragraph. -@end group -@group +@endExample +@Example longlabel This paragraph had a long label. The first character of text on the first line does not line up with the text on second and subsequent lines, although they line up with each other. -@end group -@end example +@endExample A variation of this is a bulleted list. -@c XXX description +@Example +. Bulleted lists start with a bullet. It is possible + to use other glyphs instead of the bullet. In nroff + mode using the ASCII character set for output, a dot + is used instead of a real bullet. +@endExample + @c --------------------------------------------------------------------- @@ -1858,11 +1733,15 @@ supply macros for starting chapters and appendices. @node Headers and Footers, Page Layout Adjustment, Sections and Chapters, Common Features @subsection Headers and Footers -Every macro package gives some way to manipulate the headers and footers -(or @dfn{titles}) on each page. Some packages allow for different ones -on the even and odd pages (for material printed in a book form). +Every macro package gives some way to manipulate the @dfn{headers} and +@dfn{footers} (also called @dfn{titles}) on each page. This is text +put at the top and bottom of each page, respectively, which contain +data like the current page number, the current chapter title, and so +on. Its appearance is not affected by the running text. Some packages +allow for different ones on the even and odd pages (for material printed +in a book form). -The titles are called three-part titles, that is, there is a +The titles are called @dfn{three-part titles}, that is, there is a left-justified part, a centered part, and a right-justified part. An automatically generated page number may be put in any of these fields with the @samp{%} character (see @ref{Page Layout}, for more details). @@ -1881,9 +1760,9 @@ other details about the appearance of the printed pages. @subsection Displays @cindex displays -Displays are sections of text to be set off from the body of the paper. -Major quotes, tables, and figures are types of displays, as are all the -examples used in this document. +@dfn{Displays} are sections of text to be set off from the body of +the paper. Major quotes, tables, and figures are types of displays, as +are all the examples used in this document. @cindex quotes, major @cindex major quotes @@ -1891,7 +1770,7 @@ examples used in this document. are set in from the rest of the text without quote marks around them. @cindex list -A @dfn{list} is an indented, single spaced, unfilled display. Lists +A @dfn{list} is an indented, single-spaced, unfilled display. Lists should be used when the material to be printed should not be filled and justified like normal text, such as columns of figures or the examples used in this paper. @@ -1904,7 +1783,7 @@ not. @cindex keep, floating @cindex floating keep -Floating keeps move relative to the text. Hence, they are good for +@dfn{Floating keeps} move relative to the text. Hence, they are good for things which are referred to by name, such as ``See figure@w{ }3''. A floating keep appears at the bottom of the current page if it fits; otherwise, it appears at the top of the next page. Meanwhile, the @@ -1954,6 +1833,10 @@ While some macro packages use the term @dfn{index}, none actually provide that functionality. The facilities they call indices are actually more appropriate for tables of contents. +@pindex makeindex +To produce a real index in a document, external tools like the +@code{makeindex} program are necessary. + @c --------------------------------------------------------------------- @node Paper Formats, Multiple Columns, Indices, Common Features @@ -1995,12 +1878,12 @@ various special characters. @node Preprocessor Support, Configuration and Customization, Predefined Strings, Common Features @subsection Preprocessor Support -All macro packages provide support for the various preprocessors and may +All macro packages provide support for various preprocessors and may extend their functionality. For example, all macro packages mark tables (which are processed with -@code{gtbl}) by placing them between @code{.TS} and @code{.TE} macros. -The @file{ms} macro package has an option, @code{.TS@w{}H}, that prints +@code{gtbl}) by placing them between @code{TS} and @code{TE} macros. +The @file{ms} macro package has an option, @samp{.TS@w{ }H}, that prints a caption at the top of a new page (when the table is too long to fit on a single page). @@ -2039,8 +1922,8 @@ This chapter documents the main macro packages that come with @node man, mdoc, Macro Packages, Macro Packages @section @file{man} -@cindex @file{man} @cindex manual pages +@cindex man pages @pindex an.tmac @pindex man.tmac @pindex man-old.tmac @@ -2067,7 +1950,8 @@ The command line format for using the @file{man} macros with @code{groff} is: @Example -groff -m man [ -rcR=1 ] [ -rC1 ] [ -rD1 ] [ -rP@var{nnn} ] +groff -m man [ -rLL=@var{length} ] [ -rLT=@var{length} ] + [ -rcR=1 ] [ -rC1 ] [ -rD1 ] [ -rP@var{nnn} ] [ -rS@var{xx} ] [ -rX@var{nnn} ] [ @var{files}@dots{} ] @endExample @@ -2075,8 +1959,18 @@ groff -m man [ -rcR=1 ] [ -rC1 ] [ -rD1 ] [ -rP@var{nnn} ] It is possible to use @samp{-man} instead of @w{@samp{-m man}}. @table @code +@item -rLL=@var{length} +Set line length to @var{length}. If not specified, the line length +defaults to 78@w{ }en in nroff mode (this is 78@w{ }characters per +line) and 6.5@w{ }inch otherwise. + +@item -rLT=@var{length} +Set title length to @var{length}. If not specified, the title length +defaults to 78@w{ }en in nroff mode (this is 78@w{ }characters per +line) and 6.5@w{ }inch otherwise. + @item -rcR=1 -This option (the default if a tty output device is used) creates a +This option (the default if a TTY output device is used) creates a single, very long page instead of multiple pages. Use @code{-rcR=0} to disable it. @@ -2106,7 +2000,7 @@ following page numbers: 1, 2, 2a, 2b, 2c, etc. @node Man usage, Man font macros, Man options, man @subsection Usage @cindex @code{man} macros -@cindex macros for manual pages +@cindex macros for manual pages [@code{man}] @pindex man.local This section describes the available macros for manual pages. For @@ -2114,7 +2008,7 @@ further customization, put additional macros and requests into the file @file{man.local} which is loaded immediately after the @file{man} package. -@Defmac {TH, title section [@Var{extra1}] [@Var{extra2}] [@Var{extra3}]} +@Defmac {TH, title section [@Var{extra1} [@Var{extra2} [@Var{extra3}]]], man} Set the title of the man page to @var{title} and the section to @var{section}, which must have a value between 1 and@w{ }8. The value of @var{section} may also have a string appended, e.g.@: @samp{.pm}, @@ -2137,7 +2031,7 @@ single man page should contain exactly one @code{TH} macro at the beginning of the file. @endDefmac -@Defmac {SH, [@Var{heading}]} +@Defmac {SH, [@Var{heading}], man} Set up an unnumbered section heading sticking out to the left. Prints out all the text following @code{SH} up to the end of the line (or the text in the next line if there is no argument to @code{SH}) in bold @@ -2145,7 +2039,7 @@ face, one size larger than the base document size. Additionally, the left margin for the following text is reset to its default value. @endDefmac -@Defmac {SS, [@Var{heading}]} +@Defmac {SS, [@Var{heading}], man} Set up an unnumbered (sub)section heading. Prints out all the text following @code{SS} up to the end of the line (or the text in the next line if there is no argument to @code{SS}) in bold face, at the same @@ -2153,7 +2047,7 @@ size as the base document size. Additionally, the left margin for the following text is reset to its default value. @endDefmac -@Defmac {TP, [@Var{nnn}]} +@Defmac {TP, [@Var{nnn}], man} Set up an indented paragraph with label. The indentation is set to @var{nnn} if that argument is supplied (the default unit is @samp{n} if omitted), otherwise it is set to the default indentation value. @@ -2171,17 +2065,18 @@ set to a default value; on the other hand, the rest of the text has default font settings. @endDefmac -@Defmac {LP} -@Defmacx {PP} -@Defmacx {P} +@DefmacList {LP, , man} +@DefmacItem {PP, , man} +@DefmacListEnd {P, , man} These macros are mutual aliases. Any of them causes a line break at the current position, followed by a vertical space downwards by the amount specified by the @code{PD} macro. The font size and shape are -reset to the default value (10@dmn{pt} roman). Finally, the current -left margin is restored. +reset to the default value (10@dmn{pt} roman if no @option{-rS} option +is given on the command line). Finally, the current left margin is +restored. @endDefmac -@Defmac {IP, [@Var{designator}] [@Var{nnn}]} +@Defmac {IP, [@Var{designator} [@Var{nnn}]], man} Set up an indented paragraph, using @var{designator} as a tag to mark its beginning. The indentation is set to @var{nnn} if that argument is supplied (default unit is @samp{n}), otherwise the default @@ -2192,74 +2087,79 @@ designator, use @samp{""} (two double quotes) as the first argument of @code{IP}. For example, to start a paragraph with bullets as the designator and -4@dmn{en} indentation, write +4@w{ }en indentation, write @Example .IP \(bu 4 @endExample @endDefmac -@cindex hanging indentation, in manual pages -@Defmac {HP, [@Var{nnn}]} +@Defmac {HP, [@Var{nnn}], man} +@cindex hanging indentation [@code{man}] +@cindex @code{man} macros, hanging indentation Set up a paragraph with hanging left indentation. The indentation is set to @var{nnn} if that argument is supplied (default unit is @samp{n}), otherwise the default indentation value is used. Font size and face are reset to their default values. @endDefmac -@cindex left margin, how to move, in manual pages -@Defmac {RS, [@Var{nnn}]} +@Defmac {RS, [@Var{nnn}], man} +@cindex left margin, how to move [@code{man}] +@cindex @code{man} macros, moving left margin Move the left margin to the right by the value @var{nnn} if specified -(default unit is @samp{n}); otherwise the default indentation value is -used. Calls to the @code{RS} macro can be nested. +(default unit is @samp{n}); otherwise the default indentation value +is used. Calls to the @code{RS} macro can be nested. @endDefmac -@Defmac {RE, [@Var{nnn}]} +@Defmac {RE, [@Var{nnn}], man} Move the left margin back to level @var{nnn}; if no argument is given, it moves one level back. The first level (i.e., no call to @code{RS} yet) has number@w{ }1, and each call to @code{RS} increases the level by@w{ }1. @endDefmac -@maindex SH -@maindex SS -@maindex TP -@maindex LP -@maindex PP -@maindex P -@maindex IP -@maindex HP +@cindex line breaks, with vertical space [@code{man}] +@cindex @code{man} macros, line breaks with vertical space To summarize, the following macros cause a line break with the insertion of vertical space (which amount can be changed with the @code{PD} macro): @code{SH}, @code{SS}, @code{TP}, @code{LP} (@code{PP}, @code{P}), @code{IP}, and @code{HP}. -@maindex RS -@maindex RE +@cindex line breaks, without vertical space [@code{man}] +@cindex @code{man} macros, line breaks without vertical space The macros @code{RS} and @code{RE} also cause a break but do not insert vertical space. +@cindex default indentation, resetting [@code{man}] +@cindex indentaion, resetting to default [@code{man}] +@cindex @code{man} macros, resetting default indentation +Finally, the macros @code{SH}, @code{SS}, @code{LP} (@code{PP}, @code{P}), +and @code{RS} reset the indentation to its default value. + @c --------------------------------------------------------------------- @node Man font macros, Miscellaneous man macros, Man usage, man @subsection Macros to set fonts -@cindex fonts in manual pages -@cindex @code{man}, how to set fonts +@cindex font selection [@code{man}] +@cindex @code{man} macros, how to set fonts The standard font is roman; the default text size is 10@w{ }point. +If command line option @option{-rS=@var{n}} is given, use +@var{n}@dmn{pt} as the default text size. -@Defmac {SM, [@Var{text}]} +@Defmac {SM, [@Var{text}], man} Set the text on the same line or the text on the next line in a font that is one point size smaller than the default font. @endDefmac -@cindex boldface, in manual pages -@Defmac {SB, [@Var{text}]} -Set the text on the same line or the text on the next line in boldface +@Defmac {SB, [@Var{text}], man} +@cindex bold face [@code{man}] +@cindex @code{man} macros, bold face +Set the text on the same line or the text on the next line in bold face font, one point size smaller than the default font. @endDefmac -@Defmac {BI, text} +@Defmac {BI, text, man} Set its arguments alternately in bold face and italic. Thus, @Example @@ -2271,41 +2171,35 @@ would set ``this'' and ``that'' in bold face, and ``word and'' in italics. @endDefmac -@Defmac {IB, text} +@Defmac {IB, text, man} Set its arguments alternately in italic and bold face. @endDefmac -@Defmac {RI, text} +@Defmac {RI, text, man} Set its arguments alternately in roman and italic. @endDefmac -@Defmac {IR, text} +@Defmac {IR, text, man} Set its arguments alternately in italic and roman. @endDefmac -@Defmac {BR, text} +@Defmac {BR, text, man} Set its arguments alternately in bold face and roman. @endDefmac -@Defmac {RB, text} +@Defmac {RB, text, man} Set its arguments alternately in roman and bold face. @endDefmac -@Defmac {R, [@Var{text}]} -Set @var{text} in roman font. If no text is present on the line where -the macro is called, then the text of the next line appears in roman. -This is the default font to which text is returned at the end of -processing of the other macros. -@endDefmac - -@Defmac {B, [@Var{text}]} +@Defmac {B, [@Var{text}], man} Set @var{text} in bold face. If no text is present on the line where the macro is called, then the text of the next line appears in bold face. @endDefmac -@cindex italic, in manual pages -@Defmac {I, [@Var{text}]} +@Defmac {I, [@Var{text}], man} +@cindex italic fonts [@code{man}] +@cindex @code{man} macros, italic fonts Set @var{text} in italic. If no text is present on the line where the macro is called, then the text of the next line appears in italic. @endDefmac @@ -2316,35 +2210,28 @@ macro is called, then the text of the next line appears in italic. @subsection Miscellaneous macros @pindex grohtml -@cindex @file{man}, default indentation -@cindex default indentation, @file{man} -The default indentation is 7.2@dmn{n} for all output devices except for +@cindex @code{man} macros, default indentation +@cindex default indentation [@code{man}] +The default indentation is 7.2@w{ }en for all output devices except for @code{grohtml} which ignores indentation. -@maindex TH -@cindex tab stops, in manual pages -@Defmac {DT} -Set tabs every 0.5@w{ }inches. Since this macro is always called -during a @code{TH} request, it makes sense to call it only if the tab -positions have been changed. +@Defmac {DT, , man} +@cindex tab stops [@code{man}] +@cindex @code{man} macros, tab stops +Set tabs every 0.5@w{ }inches. Since this macro is always executed +during a call to the @code{TH} macro, it makes sense to call it only if +the tab positions have been changed. @endDefmac -@cindex empty space before a paragraph, in manual pages -@Defmac {PD, [@Var{nnn}]} +@Defmac {PD, [@Var{nnn}], man} +@cindex empty space before a paragraph [@code{man}] +@cindex @code{man} macros, empty space before a paragraph Adjust the empty space before a new paragraph (or section). The optional argument gives the amount of space (default unit is @samp{v}); without parameter, the value is reset to its default value -(1@w{ }line for tty devices, 0.4@dmn{v}@w{ }otherwise). +(1@w{ }line for TTY devices, 0.4@dmn{v}@w{ }otherwise). @endDefmac -@maindex SH -@maindex SS -@maindex TP -@maindex LP -@maindex PP -@maindex P -@maindex IP -@maindex HP This affects the macros @code{SH}, @code{SS}, @code{TP}, @code{LP} (as well as @code{PP} and @code{P}), @code{IP}, and @code{HP}. @@ -2355,22 +2242,22 @@ well as @code{PP} and @code{P}), @code{IP}, and @code{HP}. The following strings are defined: -@Defstr {*S} +@Defstr {S, man} Switch back to the default font size. @endDefstr -@Defstr {*R} +@Defstr {R, man} The `registered' sign. @endDefstr -@Defstr {Tm} +@Defstr {Tm, man} The `trademark' sign. @endDefstr -@glindex lq -@glindex rq -@Defstr {lq} -@Defstrx {rq} +@DefstrList {lq, man} +@DefstrListEnd {rq, man} +@cindex @code{lq} glyph, and @code{lq} string [@code{man}] +@cindex @code{rq} glyph, and @code{rq} string [@code{man}] Left and right quote. This is equal to @code{\(lq} and @code{\(rq}, respectively. @endDefstr @@ -2387,7 +2274,7 @@ become common usage to make the first line of the man page look like this: @Example -.\" @var{word} +'\" @var{word} @endExample @pindex geqn@r{, invocation in manual pages} @@ -2406,37 +2293,1536 @@ and automatically call the right preprocessor(s). @node mdoc, ms, man, Macro Packages @section @file{mdoc} -@cindex @file{mdoc} +@cindex @code{mdoc} macros @c XXX documentation +@c XXX this is a placeholder until we get stuff knocked into shape +See the @cite{groff_mdoc(7)} man page (type @command{man groff_mdoc} +at the command line). @c ===================================================================== @node ms, me, mdoc, Macro Packages @section @file{ms} -@cindex @file{ms} +@cindex @code{ms} macros -@c XXX documentation +The @file{-ms} +macros are suitable for reports, letters, books, +user manuals, and so forth. +The package provides macros for cover pages, section headings, +paragraphs, lists, footnotes, pagination, +and a table of contents. + +@menu +* ms Intro:: +* General ms Structure:: +* ms Document Control Registers:: +* ms Cover Page Macros:: +* ms Body Text:: +* ms Page Layout:: +* Differences from AT&T ms:: +@end menu + +@c --------------------------------------------------------------------- + +@node ms Intro, General ms Structure, ms, ms +@subsection Introduction to @file{ms} + +The original @file{-ms} macros were included with +@acronym{AT&T} @code{troff} as well as the +@file{man} macros. +While the @file{man} package is intended for brief documents +that can be read on-line as well as printed, the @file{ms} +macros are suitable for longer documents that are meant to be +printed rather than read on-line. + +The @file{ms} macro package included with @code{groff} +is a complete, bottom-up re-implementation. +Several macros (specific to @acronym{AT&T} +or Berkeley) are not included, while several new commands are. +@xref{Differences from AT&T ms}, for more information. + +@c --------------------------------------------------------------------- + +@node General ms Structure, ms Document Control Registers, ms Intro, ms +@subsection General structure of an @file{ms} document +@cindex @code{ms} macros, general structure + +The @file{ms} macro package expects a certain amount of structure, +but not as much as packages such as @file{man} or @file{mdoc}. + +The simplest documents can begin with a paragraph macro +(such as @code{LP} or @code{PP}), +and consist of text separated by paragraph macros +or even blank lines. +Longer documents have a structure as follows: + +@table @strong +@item Document type +If you invoke the @code{RP} +(report) macro on the first line of the document, +@code{groff} prints the cover page information on its own page; +otherwise it prints the information on the +first page with your document text immediately following. +Other document formats found in @acronym{AT&T} @code{troff} +are specific to @acronym{AT&T} or Berkeley, and are not supported in +@code{groff}. + +@item Format and layout +By setting number registers, +you can change your document's type (font and size), +margins, spacing, headers and footers, and footnotes. +@xref{ms Document Control Registers}, for more details. + +@item Cover page +A cover page consists of a title, the author's name and institution, +an abstract, and the date. +@footnote{Actually, only the title is required.} +@xref{ms Cover Page Macros}, for more details. + +@item Body +Following the cover page is your document. +You can use the @file{ms} +macros to write reports, letters, books, and so forth. +The package is designed for structured documents, +consisting of paragraphs interspersed with headings +and augmented by lists, footnotes, tables, and other +common constructs. +@xref{ms Body Text}, for more details. + +@item Table of contents +Longer documents usually include a table of contents, +which you can invoke by placing the +@code{TC} +macro at the end of your document. +The @file{ms} +macros have minimal indexing facilities, consisting of the +@code{IX} macro, which prints an entry on standard error. +Printing the table of contents at the end is necessary since +@code{groff} is a single-pass text formatter, +thus it cannot determine the page number of each section +until that section has actually been set and printed. +Since @file{ms} output is intended for hardcopy, +you can manually relocate the pages containing +the table of contents between the cover page and the +body text after printing. +@end table + +@c --------------------------------------------------------------------- + +@node ms Document Control Registers, ms Cover Page Macros, General ms Structure, ms +@subsection Document control registers +@cindex @code{ms} macros, document control registers + +The following is a list of document control number registers. +For the sake of consistency, +set registers related to margins at the beginning of your document, +or just after the @code{RP} macro. +You can set other registers later in your document, +but you should keep them together at the beginning +to make them easy to find and edit as necessary. + +@unnumberedsubsubsec Margin Settings + +@Defmpreg {PO, ms} +Defines the page offset (i.e.@: the left margin). +There is no explicit right margin setting; the combination of +the @code{PO} and @code{LL} registers implicitly define the +right margin width. + +Effective: next page. + +Default value: 1@dmn{i}. +@endDefmpreg + +@Defmpreg {LL, ms} +Defines the line length (i.e.@: the width of the body text). + +Effective: next paragraph. + +Default: 6@dmn{i}. +@endDefmpreg + +@Defmpreg {LT, ms} +Defines the title length (i.e.@: the header and footer width). +This is usually the same as @code{LL}, but not necessarily. + +Effective: next paragraph. + +Default: 6@dmn{i}. +@endDefmpreg + +@Defmpreg {HM, ms} +Defines the header margin height at the top of the page. + +Effective: next page. + +Default: 1@dmn{i}. +@endDefmpreg + +@Defmpreg {FM, ms} +Defines the footer margin height at the bottom of the page. + +Effective: next page. + +Default: 1@dmn{i}. +@endDefmpreg + +@unnumberedsubsubsec Text Settings + +@Defmpreg {PS, ms} +Defines the point size of the body text. + +Effective: next paragraph. + +Default: 10@dmn{p}. +@endDefmpreg + +@Defmpreg {VS, ms} +Defines the space between lines (line height plus leading). + +Effective: next paragraph. + +Default: 12@dmn{p}. +@endDefmpreg + +@unnumberedsubsubsec Paragraph Settings + +@Defmpreg {PI, ms} +Defines the initial indent of a @code{.PP} paragraph. + +Effective: next paragraph. + +Default: 5@dmn{n}. +@endDefmpreg + +@Defmpreg {PD, ms} +Defines the space between paragraphs. + +Effective: next paragraph. + +Default: 0.3@dmn{v}. +@endDefmpreg + +@Defmpreg {QI, ms} +Defines the indent on both sides of a quoted (@code{.QP}) paragraph. + +Effective: next paragraph. + +Default: 5@dmn{n}. +@endDefmpreg + +@unnumberedsubsubsec Footnote Settings + +@Defmpreg {FL, ms} +Defines the length of a footnote. + +Effective: next footnote. + +Default: @math{@code{@\n[LL]} * 5 / 6}. +@endDefmpreg + +@Defmpreg {FI, ms} +Defines the footnote indent. + +Effective: next footnote. + +Default: 2@dmn{n}. +@endDefmpreg + +@Defmpreg {FF, ms} +The footnote format: +@table @code +@item 0 +Prints the footnote number as a superscript; indents the footnote (default). + +@item 1 +Prints the number followed by a period (like 1.) +and indents the footnote. + +@item 2 +Like 1, without an indent. + +@item 3 +Like 1, but prints the footnote number as a hanging paragraph. +@end table + +Effective: next footnote. + +Default: 0. +@endDefmpreg + +@unnumberedsubsubsec Miscellaneous Number Registers + +@Defmpreg {MINGW, ms} +Defines the minimum width between columns in a multi-column document. + +Effective: next page. + +Default: 2@dmn{n}. +@endDefmpreg + +@c --------------------------------------------------------------------- + +@node ms Cover Page Macros, ms Body Text, ms Document Control Registers, ms +@subsection Cover page macros +@cindex @code{ms} macros, cover page +@cindex cover page macros, [@code{ms}] + +Use the following macros to create a cover page for your document +in the order shown. + +@Defmac {RP, [@code{no}], ms} +Specifies the report format for your document. +The report format creates a separate cover page. +The default action (no @code{.RP} +macro) is to print a subset of the +cover page on page 1 of your document. + +If you use the word @code{no} as an optional argument, +@code{groff} prints a title page but +does not repeat any of the title page information +(title, author, abstract, etc.) +on page 1 of the document. +@endDefmac + +@Defmac {DA, [@dots{}], ms} +(optional) Print the current date, or the arguments to the macro if any, +on the title page (if specified) and in the footers. +This is the default for @code{nroff}. +@endDefmac + +@Defmac {ND, [@dots{}], ms} +(optional) Print the current date, or the arguments to the macro if any, +on the title page (if specified) but not in the footers. +This is the default for @code{troff}. +@endDefmac + +@Defmac {TL, , ms} +Specifies the document title. +@code{groff} collects text following the @code{.TL} +macro into the title, until reaching the author name or abstract. +@endDefmac + +@Defmac {AU, , ms} +Specifies the author's name, which appears on the +line (or lines) immediately following. +You can specify multiple authors as follows: + +@Example +.AU +John Doe +.AI +University of West Bumblefuzz +.AU +Martha Buck +.AI +Monolithic Corporation + +... +@endExample +@endDefmac + +@Defmac {AI, , ms} +Specifies the author's institution. +You can specify multiple institutions in the same way +that you specify multiple authors. +@endDefmac + +@Defmac {AB, [@code{no}], ms} +Begins the abstract. +The default is to print the word @acronym{ABSTRACT}, +centered and in italics, above the text of the abstract. +The word @code{no} as an optional argument suppresses this heading. +@endDefmac + +@Defmac {AE, , ms} +End the abstract. +@endDefmac + +The following is example mark-up for a title page. +@cindex title page, example markup +@cindex example markup, title page + +@Example +@cartouche +.RP +.TL +The Inevitability of Code Bloat +in Commercial and Free Software +.AU +J. Random Luser +.AI +University of West Bumblefuzz +.AB +This report examines the long-term growth +of the code bases in two large, popular software +packages; the free Emacs and the commercial +Microsoft Word. +While differences appear in the type or order +of features added, due to the different +methodologies used, the results are the same +in the end. +.PP +The free software approach is shown to be +superior in that while free software can +become as bloated as commercial offerings, +free software tends to have fewer serious +bugs and the added features are in line with +user demand. +.AE + +... the rest of the paper follows ... +@end cartouche +@endExample + +@c --------------------------------------------------------------------- + +@node ms Body Text, ms Page Layout, ms Cover Page Macros, ms +@subsection Body text +@cindex @code{ms} macros, body text + +This section describes macros used to mark up the body of your document. +Examples include paragraphs, sections, and other groups. + +@menu +* Paragraphs in ms:: +* Headings in ms:: +* Highlighting in ms:: +* Lists in ms:: +* Indents in ms:: +* Tabstops in ms:: +* ms Displays and Keeps:: +* ms Insertions:: +* Example multi-page table:: +* ms Footnotes:: +@end menu + +@c --------------------------------------------------------------------- + +@node Paragraphs in ms, Headings in ms, ms Body Text, ms Body Text +@subsubsection Paragraphs +@cindex @code{ms} macros, paragraph handling + +The following paragraph types are available. + +@Defmac {PP, , ms} +Sets a paragraph with an initial indent. +@endDefmac + +@Defmac {LP, , ms} +Sets a paragraph with no initial indent. +@endDefmac + +@Defmac {QP, , ms} +Sets a paragraph that is indented at both left and right margins. +The effect is identical to the @acronym{HTML} @code{<BLOCKQUOTE>} element. +The next paragraph or heading returns margins to normal. +@endDefmac + +@Defmac {XP, , ms} +Sets a paragraph whose lines are indented, +except for the first line. +This is a Berkeley extension. +@endDefmac + +The following markup uses all four paragraph macros. + +@Example +@cartouche +.NH 2 +Cases used in the study +.LP +The following software and versions were +considered for this report. +.PP +For commercial software, we chose +.B "Microsoft Word for Windows" , +starting with version 1.0 through the +current version (Word 2000). +.PP +For free software, we chose +.B Emacs , +from its first appearance as a standalone +editor through the current version (v20). +See [Bloggs 2002] for details. +.QP +Franklin's Law applied to software: +software expands to outgrow both +RAM and disk space over time. +.LP +Bibliography: +.XP +Bloggs, Joseph R., +.I "Everyone's a Critic" , +Underground Press, March 2002. +A definitive work that answers all questions +and criticisms about the quality and usability of +free software. + +@end cartouche +@endExample + +@c --------------------------------------------------------------------- + +@node Headings in ms, Highlighting in ms, Paragraphs in ms, ms Body Text +@subsubsection Headings +@cindex @code{ms} macros, headings + +Use headings to create a hierarchical structure for your document. +The @file{ms} macros print headings in @strong{bold}, +using the same font family and point size as the body text. + +The following describes the heading macros: + +@DefmacList {NH, @Var{curr-level}, ms} +@DefmacListEnd {NH, @t{S} @Var{level0} @dots{}, ms} +Numbered heading. +The argument is either a numeric argument to indicate the +level of the heading, or the letter@w{ }@code{S} followed by numeric +arguments to set the heading level explicitly. + +If you specify heading levels out of sequence, such as invoking +@samp{.NH 3} after @samp{.NH 1}, @code{groff} +prints a warning on standard error. +@endDefmac + +@Defmac {SH, , ms} +Unnumbered subheading. +@endDefmac + +@c --------------------------------------------------------------------- + +@node Highlighting in ms, Lists in ms, Headings in ms, ms Body Text +@subsubsection Highlighting +@cindex @code{ms} macros, highlighting + +The @file{ms} macros provide a variety of methods to highlight +or emphasize text: + +@Defmac {B, [@Var{txt} [@Var{post} [@Var{pre}]]], ms} +Sets its first argument in @strong{bold type}. +If you specify a second argument, @code{groff} prints it in the +previous font after the bold text, with no intervening space +(this allows you to set punctuation after the highlighted text +without highlighting the punctuation). +Similarly, it prints the third argument (if any) in the previous +font @strong{before} the first argument. +For example, + +@Example +.B foo ) ( +@endExample + +prints (@strong{foo}). + +If you give this macro no arguments, @code{groff} +prints all text following in bold until +the next highlighting, paragraph, or heading macro. +@endDefmac + +@Defmac {R, [@Var{txt} [@Var{post} [@Var{pre}]]], ms} +Sets its first argument in roman (or regular) type. +It operates similarly to the @code{B}@w{ }macro otherwise. +@endDefmac + +@Defmac {I, [@Var{txt} [@Var{post} [@Var{pre}]]], ms} +Sets its first argument in @emph{italic type}. +It operates similarly to the @code{B}@w{ }macro otherwise. +@endDefmac + +@Defmac {CW, [@Var{txt} [@Var{post} [@Var{pre}]]], ms} +Sets its first argument in a @code{constant width face}. +It operates similarly to the @code{B}@w{ }macro otherwise. +@endDefmac + +@Defmac {BI, [@Var{txt} [@Var{post} [@Var{pre}]]], ms} +Sets its first argument in bold italic type. +It operates similarly to the @code{B}@w{ }macro otherwise. +@endDefmac + +@Defmac {BX, [@Var{txt}], ms} +Prints its argument and draws a box around it. +If you want to box a string that contains spaces, +use a digit-width space (@code{\0}). +@endDefmac + +@Defmac {UL, [@Var{txt} [@Var{post}]], ms} +Prints its first argument with an underline. +If you specify a second argument, @code{groff} +prints it in the previous font after +the underlined text, with no intervening space. +@endDefmac + +@Defmac {LG, , ms} +Prints all text following in larger type +(two points larger than the current point size) until +the next font size, highlighting, paragraph, or heading macro. +You can specify this macro multiple times +to enlarge the point size as needed. +@endDefmac + +@Defmac {SM, , ms} +Prints all text following in smaller type +(two points smaller than the current point size) until +the next type size, highlighting, paragraph, or heading macro. +You can specify this macro multiple times +to reduce the point size as needed. +@endDefmac + +@Defmac {NL, , ms} +Prints all text following in the normal point size +(that is, the value of the @code{PS} register). +@endDefmac + +@c --------------------------------------------------------------------- + +@node Lists in ms, Indents in ms, Highlighting in ms, ms Body Text +@subsubsection Lists +@cindex @code{ms} macros, lists + +The @code{.IP} macro handles duties for all lists. + +@Defmac {IP, [@Var{marker} [@Var{width}]], ms} +The @var{marker} is usually a bullet glyph (@code{\[bu]}) +for unordered lists, a number (or auto-incrementing number +register) for numbered lists, or a word or phrase for indented +(glossary-style) lists. + +The @var{width} specifies the indent for the body of each list item; +its default unit is @samp{n}. +Once specified, the indent remains the same for all +list items in the document until specified again. +@endDefmac + +The following is an example of a bulleted list. +@cindex example markup, bulleted list [@code{ms}] +@cindex bulleted list, example markup [@code{ms}] + +@Example +A bulleted list: +.IP \[bu] 2 +lawyers +.IP \[bu] +guns +.IP \[bu] +money +@endExample + +Produces: + +@Example +A bulleted list: + +o lawyers + +o guns + +o money +@endExample + +@sp 1 + +The following is an example of a numbered list. +@cindex example markup, numbered list [@code{ms}] +@cindex numbered list, example markup [@code{ms}] + +@Example +.nr step 1 1 +A numbered list: +.IP \n[step] 3 +lawyers +.IP \n+[step] +guns +.IP \n+[step] +money +@endExample + +Produces: + +@Example +A numbered list: + +1. lawyers + +2. guns + +3. money +@endExample + +Note the use of the auto-incrementing number +register in this example. + +@sp 1 +The following is an example of a glossary-style list. +@cindex example markup, glossary-style list [@code{ms}] +@cindex glossary-style list, example markup [@code{ms}] + +@Example +A glossary-style list: +.IP lawyers 0.4i +Two or more attorneys. +.IP guns +Firearms, preferably +large-caliber. +.IP money +Gotta pay for those +lawyers and guns! +@endExample + +Produces: + +@Example +A glossary-style list: + +lawyers + Two or more attorneys. + +guns Firearms, preferably large-caliber. + +money + Gotta pay for those lawyers and guns! +@endExample + +In the last example, the @code{IP} macro places the definition +on the same line as the term if it has enough space; otherwise, +it breaks to the next line and starts the definition below the +term. +This may or may not be the effect you want, especially if some +of the definitions break and some do not. +The following examples show two possible ways to force a break. + +The first workaround uses the @code{br} +request to force a break after printing the term or label. + +@Example +@cartouche +A glossary-style list: +.IP lawyers 0.4i +Two or more attorneys. +.IP guns +.br +Firearms, preferably large-caliber. +.IP money +Gotta pay for those lawyers and guns! +@end cartouche +@endExample + +@sp 1 +The second workaround uses the @code{\p} escape to force the break. +Note the space following the escape; this is important. +If you omit the space, @code{groff} prints the first word on +the same line as the term or label (if it fits) @strong{then} +breaks the line. + +@Example +@cartouche +A glossary-style list: +.IP lawyers 0.4i +Two or more attorneys. +.IP guns +\p Firearms, preferably large-caliber. +.IP money +Gotta pay for those lawyers and guns! +@end cartouche +@endExample + +@sp 1 +To set nested lists, use the @code{RS} and @code{RE} macros. +@xref{Indents in ms}, for more information. +@cindex @code{ms} macros, nested lists +@cindex nested lists [@code{ms}] + +For example: + +@Example +@cartouche +.IP \[bu] 2 +Lawyers: +.RS +.IP \[bu] +Dewey, +.IP \[bu] +Cheatham, +.IP \[bu] +and Howe. +.RE +.IP \[bu] +Guns +@end cartouche +@endExample + +Produces: + +@Example +o Lawyers: + + o Dewey, + + o Cheatham, + + o and Howe. + +o Guns +@endExample + +@c --------------------------------------------------------------------- + +@node Indents in ms, Tabstops in ms, Lists in ms, ms Body Text +@subsubsection Indents + +In many situations, +you may need to indent a section of text +while still wrapping and filling. +@xref{Lists in ms}, +for an example of nested lists. + +@DefmacList {RS, , ms} +@DefmacListEnd {RE, , ms} +These macros begin and end an indented section. +The @code{PI} register controls the amount of indent, +allowing the indented text to line up under hanging +and indented paragraphs. +@endDefmac + +@xref{ms Displays and Keeps}, +for macros to indent and turn off filling. + +@c --------------------------------------------------------------------- + +@node Tabstops in ms, ms Displays and Keeps, Indents in ms, ms Body Text +@subsubsection Tab Stops + +Use the @code{ta} request to define tab stops as needed. +@xref{Tabs and Fields}. + +@Defmac{TA, , ms} +Use this macro to reset the tab stops to the default for @file{ms} +(every 5n). +You can redefine the @code{TA} macro to create a different set +of default tab stops. +@endDefmac + +@c --------------------------------------------------------------------- + +@node ms Displays and Keeps, ms Insertions, Tabstops in ms, ms Body Text +@subsubsection Displays and keeps +@cindex @code{ms} macros, displays +@cindex @code{ms} macros, keeps +@cindex keeps [@code{ms}] +@cindex displays [@code{ms}] + +Use displays to show text-based examples or figures +(such as code listings). + +Displays turn off filling, so lines of code are displayed +as-is without inserting @code{br} requests in between each line. +Displays can be @dfn{kept} on a single page, or allowed +to break across pages. + +@DefmacList {DS, @t{L}, ms} +@DefmacItem {LD, , ms} +@DefmacListEnd {DE, , ms} +Left-justified display. +The @samp{.DS L} call generates a page break, if necessary, +to keep the entire display on one page. +The @code{LD} macro allows the display to break across pages. +The @code{DE} macro ends the display. +@endDefmac + +@DefmacList {DS, @t{I}, ms} +@DefmacItem {ID, , ms} +@DefmacListEnd {DE, , ms} +Indents the display as defined by the @code{DI} register. +The @samp{.DS I} call generates a page break, if necessary, +to keep the entire display on one page. +The @code{ID} macro allows the display to break across pages. +The @code{DE} macro ends the display. +@endDefmac + +@DefmacList {DS, @t{B}, ms} +@DefmacItem {BD, , ms} +@DefmacListEnd {DE, , ms} +Sets a block-centered display: the entire display is left-justified, +but indented so that the longest line in the display is centered +on the page. +The @samp{.DS B} call generates a page break, if necessary, +to keep the entire display on one page. +The @code{BD} macro allows the display to break across pages. +The @code{DE} macro ends the display. +@endDefmac + +@DefmacList {DS, @t{C}, ms} +@DefmacItem {CD, , ms} +@DefmacListEnd {DE, , ms} +Sets a centered display: each line in the display is centered. +The @samp{.DS C} call generates a page break, if necessary, +to keep the entire display on one page. +The @code{CD} macro allows the display to break across pages. +The @code{DE} macro ends the display. +@endDefmac + +@DefmacList {DS, @t{R}, ms} +@DefmacItem {RD, , ms} +@DefmacListEnd {DE, , ms} +Right-justifies each line in the display. +The @samp{.DS R} call generates a page break, if necessary, +to keep the entire display on one page. +The @code{RD} macro allows the display to break across pages. +The @code{DE} macro ends the display. +@endDefmac + +@sp 1 +On occasion, you may want to @dfn{keep} other text together on a page. +For example, you may want to keep two paragraphs together, or +a paragraph that refers to a table (or list, or other item) +immediately following. +The @file{ms} macros provide the @code{KS} and @code{KE} +macros for this purpose. + +@DefmacList {KS, , ms} +@DefmacListEnd {KE, , ms} +The @code{KS} macro begins a block of text to be kept on a +single page, and the @code{KE} macro ends the block. +@endDefmac + +@DefmacList {KF, , ms} +@DefmacListEnd {KE, , ms} +Specifies a @dfn{floating keep}; +if the keep cannot fit on the current page, @code{groff} +holds the contents of the keep and allows text following +the keep (in the source file) to fill in the remainder of +the current page. +When the page breaks, whether by an explicit @code{bp} +request or by reaching the end of the page, @code{groff} +prints the floating keep at the top of the new page. +This is useful for printing large graphics or tables +that do not need to appear exactly where specified. +@endDefmac + +You can also use the @code{ne} request to force a page break if +there is not enough vertical space remaining on the page. + +@sp 1 +Use the following macros to draw a box around a section of +text (such as a display). + +@DefmacList {B1, , ms} +@DefmacListEnd {B2, , ms} +Marks the beginning and ending of text that is to have a +box drawn around it. +The @code{B1} macro begins the box; the @code{B2} macro ends it. +Text in the box is automatically placed in a diversion (keep). +@endDefmac + +@c --------------------------------------------------------------------- + +@node ms Insertions, Example multi-page table, ms Displays and Keeps, ms Body Text +@subsubsection Tables, figures, equations, and references +@cindex @code{ms} macros, tables +@cindex @code{ms} macros, figures +@cindex @code{ms} macros, equations +@cindex @code{ms} macros, references +@cindex tables [@code{ms}] +@cindex figures [@code{ms}] +@cindex equations [@code{ms}] +@cindex references [@code{ms}] + +The @file{ms} macros support the standard +@code{groff} preprocessors: +@code{tbl}, @code{pic}, @code{eqn}, and @code{refer}. +@pindex tbl +@pindex pic +@pindex eqn +@pindex refer +You mark text meant for preprocessors by enclosing it +in pairs of tags as follows. + +@DefmacList {TS, [@code{H}], ms} +@DefmacListEnd {TE, , ms} +Denotes a table, to be processed by the @code{tbl} preprocessor. +The optional argument@w{ }@code{H} to @code{TS} instructs @code{groff} +to create a running header with the information +up to the @code{TH} macro. +@code{groff} prints the header at the beginning of the +table; if the table runs onto another page, @code{groff} +prints the header on the next page as well. +@endDefmac + +@DefmacList {PS, , ms} +@DefmacListEnd {PE, , ms} +Denotes a graphic, to be processed by the @code{pic} preprocessor. +You can create a @code{pic} file by hand, using the @acronym{AT&T} +@code{pic} manual available on the Web as a reference, or by using +a graphics program such as @code{xfig}. +@endDefmac + +@DefmacList {EQ, [@Var{align}], ms} +@DefmacListEnd {EN, , ms} +Denotes an equation, to be processed by the @code{eqn} preprocessor. +The optional @var{align} argument can be @code{C}, @code{L}, or@w{ +}@code{I} to center (the default), left-justify, or indent the equation. +@endDefmac + +@DefmacList {[, , ms} +@DefmacListEnd {], , ms} +Denotes a reference, to be processed by the @code{refer} preprocessor. +The @acronym{GNU} @cite{refer(1)} man page provides a comprehensive +reference to the preprocessor and the format of the bibliographic +database. +@endDefmac + +@menu +* Example multi-page table:: +@end menu + +@c --------------------------------------------------------------------- + +@node Example multi-page table, ms Footnotes, ms Insertions, ms Body Text +@subsubsection An example multi-page table +@cindex example markup, multi-page table [@code{ms}] +@cindex multi-page table, example markup [@code{ms}] + +The following is an example of how to set up a +table that may print across two or more pages. + +@Example +@cartouche +.TS H +allbox expand; +cb | cb . +Text ...of heading... +_ +.TH +.T& +l | l . +... the rest of the table follows... +.CW +.TE +@end cartouche +@endExample + +@c --------------------------------------------------------------------- + +@node ms Footnotes, , Example multi-page table, ms Body Text +@subsubsection Footnotes +@cindex @code{ms} macros, footnotes +@cindex footnotes [@code{ms}] + +The @file{ms} macro package has a flexible footnote system. +You can specify either numbered footnotes or symbolic footnotes +(that is, using a marker such as a dagger symbol). + +@Defstr {*, ms} +Specifies the location of a numbered footnote marker in the text. +@endDefesc + +@DefmacList {FS, , ms} +@DefmacListEnd {FE, , ms} +Specifies the text of the footnote. +The default action is to create a numbered footnote; +you can create a symbolic footnote by specifying +a @dfn{mark} glyph +(such as @code{\[dg]} for the dagger glyph) +in the body text and as an argument to the @code{FS} macro, +followed by the text of the footnote +and the @code{FE} macro. +@endDefmac + +You can control how @code{groff} +prints footnote numbers by changing the value of the +@code{FF} register. @xref{ms Document Control Registers}. + +@c --------------------------------------------------------------------- + +@node ms Page Layout, Differences from AT&T ms, ms Body Text, ms +@subsection Page layout +@cindex @code{ms} macros, page layout +@cindex page layout [@code{ms}] + +The default output from the @file{ms} +macros provides a minimalist page layout: +it prints a single column, with the page number centered at the top +of each page. +It prints no footers. + +You can change the layout by setting +the proper number registers and strings. + +@menu +* ms Headers and Footers:: +* ms Margins:: +* ms Multiple Columns:: +* ms TOC:: +* ms Strings and Special Characters:: +@end menu + +@c --------------------------------------------------------------------- + +@node ms Headers and Footers, ms Margins, ms Page Layout, ms Page Layout +@subsubsection Headers and footers +@cindex @code{ms} macros, headers +@cindex @code{ms} macros, footers +@cindex headers [@code{ms}] +@cindex footers [@code{ms}] + +For documents that do not distinguish between odd and even pages, +set the following strings: + +@DefstrList {LH, ms} +@DefstrItem {CH, ms} +@DefstrListEnd {RH, ms} +Sets the left, center, and right headers. +@endDefstr + +@DefstrList {LF, ms} +@DefstrItem {CF, ms} +@DefstrListEnd {RF, ms} +Sets the left, center, and right footers. +@endDefstr + +@sp 1 +For documents that need different information printed in the +even and odd pages, use the following macros: + +@DefmacList {OH, @t{'}@Var{left}@t{'}@Var{center}@t{'}@Var{right}@t{'}, ms} +@DefmacItem {EH, @t{'}@Var{left}@t{'}@Var{center}@t{'}@Var{right}@t{'}, ms} +@DefmacItem {OF, @t{'}@Var{left}@t{'}@Var{center}@t{'}@Var{right}@t{'}, ms} +@DefmacListEnd {EF, @t{'}@Var{left}@t{'}@Var{center}@t{'}@Var{right}@t{'}, ms} +The @code{OH} and @code{EH} macros define headers for the odd and even pages; +the @code{OF} and @code{EF} macros define footers for the odd and even pages. +This is more flexible than defining the individual strings. + +You can replace the quote (@code{'}) marks with any character not +appearing in the header or footer text. +@endDefmac + +@c --------------------------------------------------------------------- + +@node ms Margins, ms Multiple Columns, ms Headers and Footers, ms Page Layout +@subsubsection Margins +@cindex @code{ms} macros, margins + +You control margins using a set of number registers. +@xref{ms Document Control Registers}, for details. + +@c --------------------------------------------------------------------- + +@node ms Multiple Columns, ms TOC, ms Margins, ms Page Layout +@subsubsection Multiple columns +@cindex @code{ms} macros, multiple columns +@cindex multiple columns [@code{ms}] + +The @file{ms} macros can set text in as many columns as will +reasonably fit on the page. +The following macros are available; +all of them force a page break if a multi-column mode is already set. +However, if the current mode is single-column, starting a multi-column +mode does @strong{not} force a page break. + +@Defmac {1C, , ms} +Single-column mode. +@endDefmac + +@Defmac {2C, , ms} +Two-column mode. +@endDefmac + +@Defmac {MC, [@Var{width} [@Var{gutter}]], ms} +Multi-column mode. +If you specify no arguments, it is equivalent to the +@code{2C} macro. +Otherwise, @var{width} is the width of each column and +@var{gutter} is the space between columns. +The @code{MINGW} number register controls the default gutter width. +@endDefmac + +@c --------------------------------------------------------------------- + +@node ms TOC, ms Strings and Special Characters, ms Multiple Columns, ms Page Layout +@subsubsection Creating a table of contents +@cindex @code{ms} macros, creating table of contents +@cindex table of contents, creating [@code{ms}] + +The facilities in the @file{ms} macro package for creating +a table of contents are semi-automated at best. +Assuming that you want the table of contents to consist of +the document's headings, you need to repeat those headings +wrapped in @code{XS} and @code{XE} macros. + +@DefmacList {XS, [@Var{page}], ms} +@DefmacItem {XA, [@Var{page}], ms} +@DefmacListEnd {XE, , ms} +These macros define a table of contents +or an individual entry in the table of contents, +depending on their use. +The macros are very simple; they cannot indent a heading based on its level. +The easiest way to work around this is to add tabs +to the table of contents string. +The following is an example: + +@Example +@cartouche +.NH 1 +Introduction +.XS +Introduction +.XE +.LP +... +.CW +.NH 2 +Methodology +.XS + Methodology +.XE +.LP +... +@end cartouche +@endExample + +You can manually create a table of contents +by beginning with the @code{XS} macro for the first entry, +specifying the page number for that entry as the argument to @code{XS}. +Add subsequent entries using the @code{XA} macro, +specifying the page number for that entry as the argument to @code{XA}. +The following is an example: + +@Example +@cartouche +.XS 1 +Introduction +.XA 2 +A Brief History of the Universe +.XA 729 +Details of Galactic Formation +... +.XE +@end cartouche +@endExample +@endDefmac + +@Defmac {TC, [@code{no}], ms} +Prints the table of contents on a new page, +setting the page number to@w{ }@strong{i} (Roman numeral one). +You should usually place this macro at the end of the +file, since @code{groff} is a single-pass formatter and +can only print what has been collected up to the point +that the @code{TC} macro appears. + +The optional argument @code{no} suppresses printing +the title specified by the string register @code{TOC}. +@endDefmac + +@Defmac{PX, [@code{no}], ms} +Prints the table of contents on a new page, +using the current page numbering sequence. +Use this macro to print a manually-generated table of contents +at the beginning of your document. + +The optional argument @code{no} suppresses printing +the title specified by the string register @code{TOC}. +@endDefmac + +The @cite{Groff and Friends HOWTO} +includes a @code{sed} script that automatically inserts +@code{XS} and @code{XE} macro entries after each heading in a document. + +Altering the @code{NH} macro to automatically build the table +of contents is perhaps initially more difficult, but would save +a great deal of time in the long run if you use @file{ms} regularly. + +@c --------------------------------------------------------------------- + +@node ms Strings and Special Characters, , ms TOC, ms Page Layout +@subsubsection Strings and Special Characters +@cindex @code{ms} macros, strings +@cindex @code{ms} macros, special characters +@cindex @code{ms} macros, accent marks +@cindex accent marks [@code{ms}] +@cindex special characters [@code{ms}] +@cindex strings [@code{ms}] + +The @file{ms} macros provide the following predefined strings. +You can change the string definitions to help in creating +documents in languages other than English. + +@Defstr {REFERENCES, ms} +Contains the string printed at the beginning of the +references (bibliography) page. +The default is @samp{References}. +@endDefstr + +@Defstr {ABSTRACT, ms} +Contains the string printed at the beginning of the abstract. +The default is @samp{ABSTRACT}. +@endDefstr + +@Defstr {TOC, ms} +Contains the string printed at the beginning of the table of contents. +@endDefstr + +@DefstrList {MONTH1, ms} +@DefstrItem {MONTH2, ms} +@DefstrItem {MONTH3, ms} +@DefstrItem {MONTH4, ms} +@DefstrItem {MONTH5, ms} +@DefstrItem {MONTH6, ms} +@DefstrItem {MONTH7, ms} +@DefstrItem {MONTH8, ms} +@DefstrItem {MONTH9, ms} +@DefstrItem {MONTH10, ms} +@DefstrItem {MONTH11, ms} +@DefstrListEnd {MONTH12, ms} +Prints the full name of the month in dates. +The default is @samp{January}, @samp{February}, etc. +@endDefstr + +The following special characters are available@footnote{For an +explanation what special characters are see @ref{Special Characters}.}: + +@Defstr {-, ms} +Prints an em dash. +@endDefstr + +@DefstrList {*Q, ms} +@DefstrListEnd {*U, ms} +Prints typographer's quotes in troff, +plain quotes in nroff. +@code{*Q} is the left quote and @code{*U} is the right quote. +@endDefstr + +Improved accent marks are available in the @file{ms} macros. + +@Defmac {AM, , ms} +Specify this macro at the beginning of your document +to enable extended accent marks and special characters. +This is a Berkeley extension. + +To use the accent marks, place them @strong{after} +the character being accented. +@endDefmac + +The following accent marks are available +after invoking the @code{AM} macro: + +@Defstr {\', ms} +Acute accent. +@endDefstr + +@Defstr {\`, ms} +Grave accent. +@endDefstr + +@Defstr {^, ms} +Circumflex. +@endDefstr + +@Defstr {\,, ms} +Cedilla. +@endDefstr + +@Defstr {~, ms} +Tilde. +@endDefstr + +@deffn String @t{\*[:]} +@ifnotinfo +@stindex : @r{[}ms@r{]} +@end ifnotinfo +@ifinfo +@stindex @r{<colon>} @r{[}ms@r{]} +@end ifinfo +Umlaut. +@end deffn + +@Defstr {v, ms} +Hacek. +@endDefstr + +@Defstr {_, ms} +Macron (overbar). +@endDefstr + +@Defstr {., ms} +Underdot. +@endDefstr + +@Defstr {o, ms} +Ring above. +@endDefstr + +The following are standalone characters +available after invoking the @code{AM} macro: + +@Defstr {?, ms} +Upside-down question mark. +@endDefstr + +@Defstr {!, ms} +Upside-down exclamation point. +@endDefstr + +@Defstr {8, ms} +German @ss{} ligature. +@endDefstr + +@Defstr {3, ms} +Yogh. +@endDefstr + +@Defstr {Th, ms} +Uppercase thorn. +@endDefstr + +@Defstr {th, ms} +Lowercase thorn. +@endDefstr + +@Defstr {D-, ms} +Uppercase eth. +@endDefstr + +@Defstr {d-, ms} +Lowercase eth. +@endDefstr + +@Defstr {q, ms} +Hooked o. +@endDefstr + +@Defstr {ae, ms} +Lowercase @ae{} ligature. +@endDefstr + +@Defstr {Ae, ms} +Uppercase @AE{} ligature. +@endDefstr + +@c --------------------------------------------------------------------- + +@node Differences from AT&T ms, , ms Page Layout, ms +@subsection Differences from @acronym{AT&T} @file{ms} +@cindex @code{ms} macros, differences from @acronym{AT&T} +@cindex @acronym{AT&T} @code{troff}, @code{ms} macro package differences + +This section lists the (minor) differences between the +@code{groff -ms} macros and @acronym{AT&T} +@code{troff -ms} macros. + +@menu +* Missing ms Macros:: +* Additional ms Macros:: +@end menu + +@c --------------------------------------------------------------------- + +@node Missing ms Macros, Additional ms Macros, Differences from AT&T ms, Differences from AT&T ms +@subsubsection @code{troff} macros not appearing in @code{groff} + +Macros missing from @code{groff -ms} +are cover page macros specific to Bell Labs. +The macros known to be missing are: + +@table @code +@item .TM +Technical memorandum; a cover sheet style + +@item .IM +Internal memorandum; a cover sheet style + +@item .MR +Memo for record; a cover sheet style + +@item .MF +Memo for file; a cover sheet style + +@item .EG +Engineer's notes; a cover sheet style + +@item .TR +Computing Science Tech Report; a cover sheet style + +@item .OK +Other keywords + +@item .CS +Cover sheet information + +@item .MH +A cover sheet macro +@end table + +@c --------------------------------------------------------------------- + +@node Additional ms Macros, , Missing ms Macros, Differences from AT&T ms +@subsubsection @code{groff} macros not appearing in @acronym{AT&T} @code{troff} + +The @code{groff -ms} macros have a few minor extensions +compared to the @acronym{AT&T} @code{troff -ms} macros. + +@Defmac {AM, , ms} +Improved accent marks. +@xref{ms Strings and Special Characters}, for details. +@endDefmac + +@Defmac {DS, @t{I}, ms} +Indented display. +The default behavior of @acronym{AT&T} @code{troff -ms} +was to indent; the @code{groff} default prints displays +flush left with the body text. +@endDefmac + +@Defmac {CW, , ms} +Print text in @code{constant width} (Courier) font. +@endDefmac + +@Defmac {IX, , ms} +Indexing term (printed on standard error). +You can write a script to capture and process an index +generated in this manner. +@endDefmac + +@sp 1 +The following additional number registers +appear in @code{groff -ms}: + +@Defmpreg {MINGW, ms} +Specifies a minimum space +between columns (for multi-column output); this takes the +place of the @code{GW} register that was documented but apparently +not implemented in @acronym{AT&T} @code{troff}. +@endDefmpreg + +@sp 1 +Several new string registers are available as well. +You can change these to handle (for example) the local language. +@xref{ms Strings and Special Characters}, for details. @c ===================================================================== @node me, mm, ms, Macro Packages @section @file{me} -@cindex @file{me} +@cindex @code{me} macro package @c XXX documentation +@c XXX this is a placeholder until we get stuff knocked into shape +See the @file{meintro.me} and @file{meref.me} documents in +groff's @file{doc} directory. @c ===================================================================== @node mm, , me, Macro Packages @section @file{mm} -@cindex @file{mm} +@cindex @code{mm} macro package @c XXX documentation - +@c XXX this is a placeholder until we get stuff knocked into shape +See the @cite{groff_mm(7)} man page (type @command{man groff_mm} at +the command line). @c ===================================================================== @@ -2445,7 +3831,7 @@ and automatically call the right preprocessor(s). @node gtroff Reference, Preprocessors, Macro Packages, Top @chapter @code{gtroff} Reference @cindex reference, @code{gtroff} -@cindex @code{gtroff} reference +@cindex @code{gtroff}, reference This chapter covers @strong{all} of the facilities of @code{gtroff}. Users of macro packages may skip it if not interested in details. @@ -2466,6 +3852,7 @@ Users of macro packages may skip it if not interested in details. * Character Translations:: * Troff and Nroff Mode:: * Line Layout:: +* Line Control:: * Page Layout:: * Page Control:: * Fonts:: @@ -2479,13 +3866,13 @@ Users of macro packages may skip it if not interested in details. * Diversions:: * Environments:: * Suppressing output:: +* Colors:: * I/O:: * Postprocessor Access:: * Miscellaneous:: * Gtroff Internals:: * Debugging:: * Implementation Differences:: -* Summary:: @end menu @@ -2541,7 +3928,7 @@ it. This means it widens the spacing between words until the text reaches the right margin (in the default adjustment mode). Extra spaces between words are preserved, but spaces at the end of lines are ignored. Spaces at the front of a line cause a @dfn{break} (breaks are -explained in @ref{Implicit Line Breaks}) +explained in @ref{Implicit Line Breaks}). @xref{Manipulating Filling and Adjusting}. @@ -2582,7 +3969,7 @@ a comma or a period as part of an abbreviation. @cindex space between sentences @cindex french-spacing @code{gtroff} does this by flagging certain characters (normally -@samp{!}, @samp{?}, and @samp{.}) as @dfn{end of sentence} characters. +@samp{!}, @samp{?}, and @samp{.}) as @dfn{end-of-sentence} characters. When @code{gtroff} encounters one of these characters at the end of a line, it appends a normal space followed by a @dfn{sentence space} in the formatted output. (This justifies one of the conventions mentioned @@ -2590,21 +3977,21 @@ in @ref{Input Conventions}.) @cindex transparent characters @cindex character, transparent -@glindex dg -@glindex rq -@cindex " -@cindex ' -@cindex ) -@cindex ] -@cindex * -In addition, the following characters or glyphs are treated -transparently while handling end of sentence characters: @samp{"}, -@samp{'}, @samp{)}, @samp{]}, @samp{*}, @code{dg}, and @code{rq}. +@cindex @code{dg} glyph, at end of sentence +@cindex @code{rq} glyph, at end of sentence +@cindex @code{"}, at end of sentence +@cindex @code{'}, at end of sentence +@cindex @code{)}, at end of sentence +@cindex @code{]}, at end of sentence +@cindex @code{*}, at end of sentence +In addition, the following characters and symbols are treated +transparently while handling end-of-sentence characters: @samp{"}, +@samp{'}, @samp{)}, @samp{]}, @samp{*}, @code{\[dg]}, and @code{\[rq]}. See the @code{cflags} request in @ref{Using Symbols}, for more details. -@esindex \& -To prevent the insertion of extra space after an end of sentence +@cindex @code{\&}, at end of sentence +To prevent the insertion of extra space after an end-of-sentence character (at the end of a line), append @code{\&}. @c --------------------------------------------------------------------- @@ -2617,6 +4004,7 @@ character (at the end of a line), append @code{\&}. @cindex character, tabulator @cindex @acronym{EBCDIC} encoding +@cindex encoding, @acronym{EBCDIC} @code{gtroff} translates @dfn{tabulator characters}, also called @dfn{tabs} (normally code point @acronym{ASCII} @code{0x09} or @acronym{EBCDIC} @code{0x05}), in the input into movements to the next @@ -2664,14 +4052,12 @@ line. @cindex blank line @cindex empty line @cindex line, blank -@cindex blank line macro -@rqindex blm +@cindex blank line macro (@code{blm}) There are several ways to cause a break in @code{gtroff}. A blank -line not only causes a break, but it also outputs a one line vertical +line not only causes a break, but it also outputs a one-line vertical space (effectively a blank line). Note that this behaviour can be modified with the blank line macro request @code{blm}. - -@c XXX xref for blm +@xref{Blank Line Traps}. @cindex fill mode @cindex mode, fill @@ -2721,9 +4107,9 @@ don't try using spaces to get proper indentation). @cindex measurements @cindex units of measurement -@cindex basic units -@cindex machine units -@cindex measurement units +@cindex basic unit (@code{u}) +@cindex machine unit (@code{u}) +@cindex measurement unit @cindex @code{u} unit @cindex unit, @code{u} @code{gtroff} (like many other programs) requires numeric parameters to @@ -2744,7 +4130,7 @@ current settings (e.g.@: type size) of @code{gtroff}. @table @code @item i -@cindex inch +@cindex inch unit (@code{i}) @cindex @code{i} unit @cindex unit, @code{i} Inches. An antiquated measurement unit still in use in certain @@ -2752,20 +4138,20 @@ backwards countries with incredibly low-cost computer equipment. One inch is equal to@w{ }2.54@dmn{cm}. @item c -@cindex centimeter +@cindex centimeter unit (@code{c}) @cindex @code{c} unit @cindex unit, @code{c} Centimeters. One centimeter is equal to@w{ }0.3937@dmn{in}. @item p -@cindex points +@cindex point unit (@code{p}) @cindex @code{p} unit @cindex unit, @code{p} Points. This is a typesetter's measurement used for measure type size. It is 72@w{ }points to an inch. @item P -@cindex pica +@cindex pica unit (@code{P}) @cindex @code{P} unit @cindex unit, @code{P} Pica. Another typesetting measurement. 6@w{ }Picas to an inch (and @@ -2778,6 +4164,12 @@ Pica. Another typesetting measurement. 6@w{ }Picas to an inch (and @cindex @code{z} unit @cindex unit, @code{z} @xref{Fractional Type Sizes}, for a discussion of these units. + +@item f +@cindex @code{f} unit +@cindex unit, @code{f} +Fractions. Value is 65536. +@xref{Colors}, for usage. @end table The other measurements understood by @code{gtroff} depend on @@ -2787,7 +4179,7 @@ text. @table @code @item m -@cindex em unit +@cindex em unit (@code{m}) @cindex @code{m} unit @cindex unit, @code{m} Ems. This unit is equal to the current font size in points. So called @@ -2795,14 +4187,14 @@ because it is @emph{approximately} the width of the letter@w{ }@samp{m} in the current font. @item n -@cindex en unit +@cindex en unit (@code{n}) @cindex @code{n} unit @cindex unit, @code{n} -Ens. This is half of an em. +Ens. In @code{groff}, this is half of an em. @item v -@cindex vertical space -@cindex space, vertical +@cindex vertical space unit (@code{v}) +@cindex space, vertical, unit (@code{v}) @cindex @code{v} unit @cindex unit, @code{v} Vertical space. This is equivalent to the current line spacing. @@ -2834,6 +4226,7 @@ line length of 3.5@w{ }inches and their results: 3.5i @result{} 3.5i 7/2 @result{} 0i 7/2i @result{} 0i +(7 / 2)u @result{} 0i 7i/2 @result{} 0.1i 7i/2u @result{} 3.5i @endExample @@ -2844,7 +4237,8 @@ is assumed that 1@dmn{i} equals@w{ }240@dmn{u}, and 1@dmn{m} equals@w{ }10@dmn{p} (thus 1@dmn{m} equals@w{ }33@dmn{u}). The value 7@dmn{i}/2 is first handled as 7@dmn{i}/2@dmn{m}, then converted to 1680@dmn{u}/66@dmn{u} which is 25@dmn{u}, and this is approximately -0.1@dmn{i}. +0.1@dmn{i}. As can be seen, a scaling indicator after a closing +parenthesis is simply ignored. @cindex measurements, specifying safely Thus, the safest way to specify measurements is to always @@ -2860,8 +4254,6 @@ certain scalar value, use @samp{u} as the unit for that value. @code{gtroff} has most arithmetic operators common to other languages: -@c XXX more details; examples - @itemize @bullet @item @cindex arithmetic operators @@ -2895,7 +4287,12 @@ Comparison: @samp{<} (less than), @samp{>} (greater than), @samp{<=} @cindex logical operators @cindex operators, logical @opindex & +@ifnotinfo @opindex : +@end ifnotinfo +@ifinfo +@opindex @r{<colon>} +@end ifinfo Logical: @samp{&} (logical and), @samp{:} (logical or). @item @@ -2904,31 +4301,37 @@ Logical: @samp{&} (logical and), @samp{:} (logical or). @opindex - @opindex + @opindex ! -@rqindex if -@rqindex while -@cindex @code{if}, and the @samp{!} operator -@cindex @code{while}, and the @samp{!} operator +@cindex @code{if} request, and the @samp{!} operator +@cindex @code{while} request, and the @samp{!} operator Unary operators: @samp{-} (negating, i.e.@: changing the sign), @samp{+} (just for completeness; does nothing in expressions), @samp{!} (logical not; this works only within @code{if} and @code{while} requests). See below for the use of unary operators in motion requests. @item -@cindex extremum operators -@cindex operators, extremum +@cindex extremum operators (@code{>?}, @code{<?}) +@cindex operators, extremum (@code{>?}, @code{<?}) @opindex >? @opindex <? -Extrema: @samp{>?} (maximum), @samp{<?} (minimum). For example, -@samp{5>?3} yields@w{ }@samp{5}. +Extrema: @samp{>?} (maximum), @samp{<?} (minimum). + +Example: -@c XXX add examples +@Example +.nr x 5 +.nr y 3 +.nr z (\n[x] >? \n[y]) +@endExample + +@noindent +The register@w{ }@code{z} now contains@w{ }5. @item @cindex scaling operator @cindex operator, scaling -Scaling: @code{(@var{c};@var{e})}. Evaluate @var{e} using @var{c} as -the default scaling indicator. If @var{c} is missing, ignore scaling -indicators in the evaluation of @var{e}. +Scaling: @code{(@var{c};@var{e})}. Evaluate@w{ }@var{e} using@w{ }@var{c} +as the default scaling indicator. If @var{c} is missing, ignore scaling +indicators in the evaluation of@w{ }@var{e}. @end itemize @cindex parentheses @@ -2943,28 +4346,56 @@ to right. This means that @code{gtroff} evaluates @samp{3+5*4} as if it were parenthesized like @samp{(3+5)*4}, not as @samp{3+(5*4)}, as might be expected. -@opindex +@r{, and page motion} -@opindex -@r{, and page motion} -@opindex |@r{, and page motion} +@cindex @code{+}, and page motion +@cindex @code{-}, and page motion @cindex motion operators @cindex operators, motion For many requests which cause a motion on the page, the unary operators -work differently. The @samp{+} and @samp{-} operators then indicate a -motion relative to the current position (down or up, respectively), and -the @samp{|} operator indicates an absolute position on the page or -input line. -@c XXX xref +@samp{+} and @samp{-} work differently if leading an expression. They +then indicate a motion relative to the current position (down or up, +respectively). + +@cindex @code{|}, and page motion +@cindex absolute position operator (@code{|}) +@cindex position, absolute, operator (@code{|}) +Similarly, a leading @samp{|} operator indicates an absolute position. +For vertical movements, it specifies the distance from the top of the +page; for horizontal movements, it gives the distance from the beginning +of the @emph{input} line. + +@cindex @code{bp} request, using @code{+} and@w{ }@code{-} +@cindex @code{in} request, using @code{+} and@w{ }@code{-} +@cindex @code{ll} request, using @code{+} and@w{ }@code{-} +@cindex @code{lt} request, using @code{+} and@w{ }@code{-} +@cindex @code{nm} request, using @code{+} and@w{ }@code{-} +@cindex @code{nr} request, using @code{+} and@w{ }@code{-} +@cindex @code{pl} request, using @code{+} and@w{ }@code{-} +@cindex @code{pn} request, using @code{+} and@w{ }@code{-} +@cindex @code{po} request, using @code{+} and@w{ }@code{-} +@cindex @code{ps} request, using @code{+} and@w{ }@code{-} +@cindex @code{pvs} request, using @code{+} and@w{ }@code{-} +@cindex @code{rt} request, using @code{+} and@w{ }@code{-} +@cindex @code{ti} request, using @code{+} and@w{ }@code{-} +@cindex @code{\H}, using @code{+} and@w{ }@code{-} +@cindex @code{\R}, using @code{+} and@w{ }@code{-} +@cindex @code{\s}, using @code{+} and@w{ }@code{-} @samp{+} and @samp{-} are also treated differently by the following requests and escapes: @code{bp}, @code{in}, @code{ll}, @code{lt}, @code{nm}, @code{nr}, @code{pl}, @code{pn}, @code{po}, @code{ps}, -@code{rt}, @code{ti}, @code{\R}, and @code{\s}. Here the plus and minus -signs indicate increments and decrements. +@code{pvs}, @code{rt}, @code{ti}, @code{\H}, @code{\R}, and @code{\s}. +Here, leading plus and minus signs indicate increments and decrements. -@c XXX add more xref -@xref{Setting Registers}. +@xref{Setting Registers}, for some examples. -@cindex space characters in expressions -@cindex expressions and space characters +@Defesc {\\B, ', anything, '} +@cindex numeric expression, valid +@cindex valid numeric expression +Return@w{ }1 if @var{anything} is a valid numeric expression; +or@w{ }0 if @var{anything} is empty or not a valid numeric expression. +@endDefesc + +@cindex space characters, in expressions +@cindex expressions, and space characters Due to the way arguments are parsed, spaces are not allowed in expressions, unless the entire expression is surrounded by parentheses. @@ -3000,7 +4431,7 @@ Backspace (@acronym{ASCII}@w{ }@code{0x08} or @acronym{EBCDIC}@w{ @cindex invalid input characters @cindex input characters, invalid @cindex characters, invalid input -@cindex unicode +@cindex Unicode The following input characters are invalid and are ignored if @code{groff} runs on a machine based on @acronym{ASCII}, causing a warning message of type @samp{input} (see @ref{Debugging}, for more @@ -3031,7 +4462,7 @@ end-list @@_ @endExample -@rqindex ] +@cindex @code{]}, as part of an identifier @noindent Note that identifiers longer than two characters with a closing bracket (@samp{]}) in its name can't be accessed with escape sequences which @@ -3039,7 +4470,15 @@ expect an identifier as a parameter. For example, @samp{\[foo]]} accesses the glyph @samp{foo}, followed by @samp{]}, whereas @samp{\C'foo]'} really asks for glyph @samp{foo]}. -@c XXX xref +@cindex @code{refer}, and macro names starting with @code{[} or @code{]} +@cindex @code{[}, macro names starting with, and @code{refer} +@cindex @code{]}, macro names starting with, and @code{refer} +@cindex macro names, starting with @code{[} or @code{]}, and @code{refer} +To avoid problems with the @code{refer} preprocessor, macro names +should not start with @samp{[} or @samp{]}. Due to backwards +compatibility, everything after @samp{.[} and @samp{.]} is handled as +a special argument to @code{refer}. For example, @samp{.[foo} makes +@code{refer} to start a reference, using @samp{foo} as a parameter. @Defesc {\\A, ', ident, '} Test whether an identifier @var{ident} is valid in @code{gtroff}. It @@ -3057,22 +4496,20 @@ looking up user input in some sort of associative table. @xref{Escapes}, for details on parameter delimiting characters. -@c XXX add xrefs above - Identifiers in @code{gtroff} can be any length, but, in some contexts, @code{gtroff} needs to be told where identifiers end and text begins (and in different ways depending on their length): -@rqindex ( -@rqindex [ -@rqindex ] @itemize @bullet @item Single character. +@cindex @code{(}, starting a two-character identifier @item Two characters. Must be prefixed with @samp{(} in some situations. +@cindex @code{[}, starting an identifier +@cindex @code{]}, ending an identifier @item Arbitrary length (@code{gtroff} only). Must be bracketed with @samp{[} and@w{ }@samp{]} in some situations. Any length identifier can be put @@ -3080,11 +4517,11 @@ in brackets. @end itemize @cindex undefined identifiers -@cindex indentifiers, undefined +@cindex identifiers, undefined Unlike many other programming languages, undefined identifiers are silently ignored or expanded to nothing. When @code{gtroff} finds an undefined identifier, it emits a -warning then: +warning, doing the following: @itemize @bullet @item @@ -3096,9 +4533,29 @@ If the identifier is a number register, @code{gtroff} defines it with a value of@w{ }0. @end itemize -@xref{Warnings}. +@xref{Warnings}., @ref{Interpolating Registers}, and @ref{Strings}. + +Note that macros, strings, and diversions share the same name space. + +@Example +.de xxx +. nop foo +.. +. +.di xxx +bar +.br +.di +. +.xxx + @result{} bar +@endExample -@c XXX info about common identifier pool for strings and macros. +@noindent +As can be seen in the previous example, @code{gtroff} reuses the +identifier @samp{xxx}, changing it from a macro to a diversion. +No warning is emitted! The contents of the first macro definition is +lost. @xref{Interpolating Registers}, and @ref{Strings}. @@ -3117,9 +4574,8 @@ implicit line breaking. In order to gain further functionality, The first is a @dfn{request} which takes up an entire line, and does some large-scale operation (e.g.@: break lines, start new pages). -The other is an @dfn{escape} which can be embedded anywhere in the text, -or even as an argument to a request. -@c XXX (Not always?) +The other is an @dfn{escape} which can be usually embedded anywhere +in the text; most requests can accept it even as an argument. Escapes generally do more minor operations like sub- and superscripts, print a symbol, etc. @@ -3135,13 +4591,11 @@ print a symbol, etc. @subsection Requests @cindex requests -@cindex control character -@cindex character, control -@cindex no-break control character -@cindex character, no-break control -@cindex control character, no-break -@rqindex ' -@rqindex . +@cindex control character (@code{.}) +@cindex character, control (@code{.}) +@cindex no-break control character (@code{'}) +@cindex character, no-break control (@code{'}) +@cindex control character, no-break (@code{'}) A request line begins with a control character, which is either a single quote (@samp{'}, the @dfn{no-break control character}) or a period (@samp{.}, the normal @dfn{control character}). These can be changed; @@ -3152,7 +4606,7 @@ arguments (@emph{no} tabs here). @cindex structuring source code of documents or macro packages @cindex documents, structuring the source code -@cindex macro packages, strucuring the source code +@cindex macro packages, structuring the source code Since a control character followed by whitespace only is ignored, it is common practice to use this feature for structuring the source code of documents or macro packages. @@ -3169,8 +4623,7 @@ of documents or macro packages. @endExample @cindex blank line -@cindex blank line macro -@rqindex blm +@cindex blank line macro (@code{blm}) Another possibility is to use the blank line macro request @code{blm} by assigning an empty macro to it. @@ -3191,12 +4644,11 @@ by assigning an empty macro to it. .blm \" deactivate blank line macro @endExample -@c XXX xref to blm +@xref{Blank Line Traps}. -@cindex zero width space character -@cindex character, zero width space -@cindex space character, zero width -@esindex \& +@cindex zero width space character (@code{\&}) +@cindex character, zero width space (@code{\&}) +@cindex space character, zero width (@code{\&}) @cindex @code{\&}, escaping control characters To begin a line with a control character without it being interpreted, precede it with @code{\&}. This represents a zero width space, which @@ -3216,9 +4668,12 @@ character prevents this. @cindex arguments to requests Arguments to requests (and macros) are processed much like the shell: -The line is split into arguments according to spaces. An argument -which is intended to contain spaces can either be enclosed in double -quotes, or have the spaces @dfn{escaped} with backslashes. +The line is split into arguments according to +spaces.@footnote{Plan@w{ }9's @code{troff} implementation also allows +tabs for argument separation -- @code{gtroff} intentionally doesn't +support this.} An argument which is intended to contain spaces can +either be enclosed in double quotes, or have the spaces @dfn{escaped} +with backslashes. Here are a few examples: @@ -3228,8 +4683,8 @@ Here are a few examples: .uh The\ Mouse\ Problem @endExample -@esindex \~ -@esindex \@key{SP} +@cindex @code{\~}, difference to @code{\@key{SP}} +@cindex @code{\@key{SP}}, difference to @code{\~} @noindent The first line is the @code{uh} macro being called with 3 arguments, @samp{The}, @samp{Mouse}, and @samp{Problem}. The latter two have the @@ -3241,8 +4696,8 @@ documents. Nevertheless, it is not optimal in all situations, since can't stretch. @code{gtroff} provides a different command @code{\~} to insert a stretchable, non-breaking space.} -@cindex @code{"}, as a macro argument -@cindex double quote, as a macro argument +@cindex @code{"}, in a macro argument +@cindex double quote, in a macro argument A double quote which isn't preceded by a space doesn't start a macro argument. If not closing a string, it is printed literally. @@ -3254,9 +4709,53 @@ For example, @noindent has the arguments @samp{a"}, @w{@samp{b c}}, @samp{de}, and @samp{fg"}. +Don't rely on this obscure behaviour! -@rqindex ds -Duoble quotes in the @code{ds} request are handled differently. +There are two possibilities to get a double quote reliably. + +@itemize @bullet +@item +Enclose the whole argument with double quotes and use two consecutive double +quotes to represent a single one. This traditional solution has the +disadvantage that double quotes don't survive argument expansion again if +called in compatibility mode (using the @option{-C} option of @code{groff}): + +@Example +.de xx +. tm xx: `\\$1' `\\$2' `\\$3' +. +. yy "\\$1" "\\$2" "\\$3" +.. +.de yy +. tm yy: `\\$1' `\\$2' `\\$3' +.. +.xx A "test with ""quotes""" . + @result{} xx: `A' `test with "quotes"' `.' + @result{} yy: `A' `test with ' `quotes""' +@endExample + +@noindent +If not in compatibility mode, you get the expected result + +@Example +xx: `A' `test with "quotes"' `.' +yy: `A' `test with "quotes"' `.' +@endExample + +@noindent +since @code{gtroff} preserves the input level. + +@item +Use the double quote glyph @code{\(dq}. This works with and without +compatibility mode enabled since @code{gtroff} doesn't convert @code{\(dq} +back to a double quote input character. + +Not that this method won't work with @acronym{UNIX} @code{troff} in general +since the glyph `dq' isn't defined normally. +@end itemize + +@cindex @code{ds} request, and double quotes +Double quotes in the @code{ds} request are handled differently. @xref{Strings}, for more details. @c --------------------------------------------------------------------- @@ -3282,9 +4781,6 @@ begin with a backslash and are followed by a single character which indicates the function to be performed. The escape character can be changed; see @ref{Character Translations}. -@rqindex ( -@rqindex [ -@rqindex ] Escape sequences which require an identifier as a parameter accept three possible syntax forms. @@ -3292,11 +4788,14 @@ possible syntax forms. @item The next single character is the identifier. +@cindex @code{(}, starting a two-character identifier @item If this single character is an opening parenthesis, take the following two characters as the identifier. Note that there is no closing parenthesis after the identifier. +@cindex @code{[}, starting an identifier +@cindex @code{]}, ending an identifier @item If this single character is an opening bracket, take all characters until a closing bracket as the identifier. @@ -3311,7 +4810,7 @@ Examples: \*[TeX] @endExample -@rqindex ' +@cindex @code{'}, delimiting arguments @cindex argument delimiting characters @cindex characters, argument delimiting @cindex delimiting characters for arguments @@ -3325,9 +4824,9 @@ escape expects. Example: \l'1.5i\(bu' @endExample -@esindex \o -@esindex \b -@esindex \X +@cindex @code{\o}, possible quote characters +@cindex @code{\b}, possible quote characters +@cindex @code{\X}, possible quote characters Note that the quote character can be replaced with any other character which does not occur in the argument (even a newline or a space character) in the following escapes: @code{\o}, @code{\b}, and @@ -3346,86 +4845,98 @@ in Paris @noindent possible, but it is better not to use this feature to avoid confusion. -@esindex \% -@esindex \@key{SP} -@esindex \| -@esindex \^ -@esindex \@{ -@esindex \@} -@esindex \' -@esindex \` -@esindex \- -@esindex \_ -@esindex \! -@esindex \? -@esindex \@@ -@esindex \) -@esindex \/ -@esindex \, -@esindex \& -@esindex \~ -@esindex \0 -@esindex \a -@esindex \c -@esindex \d -@esindex \e -@esindex \E -@esindex \p -@esindex \r -@esindex \t -@esindex \u +@cindex @code{\%}, used as delimiter +@cindex @code{\@key{SP}}, used as delimiter +@cindex @code{\|}, used as delimiter +@cindex @code{\^}, used as delimiter +@cindex @code{\@{}, used as delimiter +@cindex @code{\@}}, used as delimiter +@cindex @code{\'}, used as delimiter +@cindex @code{\`}, used as delimiter +@cindex @code{\-}, used as delimiter +@cindex @code{\_}, used as delimiter +@cindex @code{\!}, used as delimiter +@cindex @code{\?}, used as delimiter +@cindex @code{\@@}, used as delimiter +@cindex @code{\)}, used as delimiter +@cindex @code{\/}, used as delimiter +@cindex @code{\,}, used as delimiter +@cindex @code{\&}, used as delimiter +@ifnotinfo +@cindex @code{\:}, used as delimiter +@end ifnotinfo +@ifinfo +@cindex @code{\@r{<colon>}}, used as delimiter +@end ifinfo +@cindex @code{\~}, used as delimiter +@cindex @code{\0}, used as delimiter +@cindex @code{\a}, used as delimiter +@cindex @code{\c}, used as delimiter +@cindex @code{\d}, used as delimiter +@cindex @code{\e}, used as delimiter +@cindex @code{\E}, used as delimiter +@cindex @code{\p}, used as delimiter +@cindex @code{\r}, used as delimiter +@cindex @code{\t}, used as delimiter +@cindex @code{\u}, used as delimiter The following escapes sequences (which are handled similarly to characters since they don't take a parameter) are also allowed as delimiters: @code{\%}, @w{@samp{\ }}, @code{\|}, @code{\^}, @code{\@{}, @code{\@}}, @code{\'}, @code{\`}, @code{\-}, @code{\_}, @code{\!}, @code{\?}, @code{\@@}, @code{\)}, @code{\/}, @code{\,}, @code{\&}, -@code{\~}, @code{\0}, @code{\a}, @code{\c}, @code{\d}, @code{\e}, -@code{\E}, @code{\p}, @code{\r}, @code{\t}, and @code{\u}. Again, don't -use these if possible. - -@esindex \A -@esindex \Z -@esindex \C -@esindex \w +@code{\:}, @code{\~}, @code{\0}, @code{\a}, @code{\c}, @code{\d}, +@code{\e}, @code{\E}, @code{\p}, @code{\r}, @code{\t}, and @code{\u}. +Again, don't use these if possible. + +@cindex @code{\A}, allowed delimiters +@cindex @code{\B}, allowed delimiters +@cindex @code{\Z}, allowed delimiters +@cindex @code{\C}, allowed delimiters +@cindex @code{\w}, allowed delimiters No newline characters as delimiters are allowed in the following -escapes: @code{\A}, @code{\Z}, @code{\C}, and @code{\w}. - -@esindex \D -@esindex \h -@esindex \H -@esindex \l -@esindex \L -@esindex \N -@esindex \R -@esindex \s -@esindex \S -@esindex \v -@esindex \x +escapes: @code{\A}, @code{\B}, @code{\Z}, @code{\C}, and @code{\w}. + +@cindex @code{\D}, allowed delimiters +@cindex @code{\h}, allowed delimiters +@cindex @code{\H}, allowed delimiters +@cindex @code{\l}, allowed delimiters +@cindex @code{\L}, allowed delimiters +@cindex @code{\N}, allowed delimiters +@cindex @code{\R}, allowed delimiters +@cindex @code{\s}, allowed delimiters +@cindex @code{\S}, allowed delimiters +@cindex @code{\v}, allowed delimiters +@cindex @code{\x}, allowed delimiters Finally, the escapes @code{\D}, @code{\h}, @code{\H}, @code{\l}, -@code{\L}, @code{\N}, @code{\R}, @code{\s}, @code{\S}, @code{\v}, and -@code{\x} can't use the following characters as delimiters: +@code{\L}, @code{\N}, @code{\R}, @code{\s}, @code{\S}, @code{\v}, +and @code{\x} can't use the following characters as delimiters: @itemize @bullet @item -@cindex numbers -@cindex digits +@cindex numbers, and delimiters +@cindex digits, and delimiters The digits @code{0}-@code{9}. @item -@cindex operators -@opindex + -@opindex - -@opindex / -@opindex * -@opindex % -@opindex < -@opindex > -@opindex = -@opindex & -@opindex : -@opindex ( -@opindex ) -@opindex . +@cindex operators, as delimiters +@cindex @code{+}, as delimiter +@cindex @code{-}, as delimiter +@cindex @code{/}, as delimiter +@cindex @code{*}, as delimiter +@cindex @code{%}, as delimiter +@cindex @code{<}, as delimiter +@cindex @code{>}, as delimiter +@cindex @code{=}, as delimiter +@cindex @code{&}, as delimiter +@ifnotinfo +@cindex @code{:}, as delimiter +@end ifnotinfo +@ifinfo +@cindex <colon>, as delimiter +@end ifinfo +@cindex @code{(}, as delimiter +@cindex @code{)}, as delimiter +@cindex @code{.}, as delimiter The (single-character) operators @samp{+-/*%<>=&:().}. @item @@ -3438,36 +4949,40 @@ The (single-character) operators @samp{+-/*%<>=&:().}. The space, tab, and newline characters. @item -@esindex \% -@esindex \@{ -@esindex \@} -@esindex \' -@esindex \` -@esindex \- -@esindex \_ -@esindex \! -@esindex \@@ -@esindex \/ -@esindex \c -@esindex \e -@esindex \p -All escape sequences except @code{\%}, @code{\@{}, @code{\@}}, +@cindex @code{\%}, used as delimiter +@ifnotinfo +@cindex @code{\:}, used as delimiter +@end ifnotinfo +@ifinfo +@cindex @code{\@r{<colon>}}, used as delimiter +@end ifinfo +@cindex @code{\@{}, used as delimiter +@cindex @code{\@}}, used as delimiter +@cindex @code{\'}, used as delimiter +@cindex @code{\`}, used as delimiter +@cindex @code{\-}, used as delimiter +@cindex @code{\_}, used as delimiter +@cindex @code{\!}, used as delimiter +@cindex @code{\@@}, used as delimiter +@cindex @code{\/}, used as delimiter +@cindex @code{\c}, used as delimiter +@cindex @code{\e}, used as delimiter +@cindex @code{\p}, used as delimiter +All escape sequences except @code{\%}, @code{\:}, @code{\@{}, @code{\@}}, @code{\'}, @code{\`}, @code{\-}, @code{\_}, @code{\!}, @code{\@@}, @code{\/}, @code{\c}, @code{\e}, and @code{\p}. @end itemize -@esindex \\ -@esindex \e -@esindex \E +@cindex printing backslash (@code{\\}, @code{\e}, @code{\E}, @code{\[rs]}) +@cindex backslash, printing (@code{\\}, @code{\e}, @code{\E}, @code{\[rs]}) To have a backslash (actually, the current escape character) appear in the output several escapes are defined: @code{\\}, @code{\e} or @code{\E}. These are very similar, and only differ with respect to being used in -macros or diversions. @xref{Copy-in Mode}, and @ref{Diversions}, for -more information. - -@c XXX explanation of \E +macros or diversions. @xref{Character Translations}, for an exact +description of those escapes. -@xref{Identifiers}, and @ref{Character Translations}. +@xref{Implementation Differences}, @ref{Copy-in Mode}, and @ref{Diversions}, +@ref{Identifiers}, for more information. @menu * Comments:: @@ -3487,17 +5002,17 @@ Start a comment. Everything to the end of the input line is ignored. This may sound simple, but it can be tricky to keep the comments from interfering with the appearance of the final output. -@rqindex ds -@rqindex as +@cindex @code{ds}, @code{ds1} requests, and comments +@cindex @code{as}, @code{as1} requests, and comments If the escape is to the right of some text or a request, that portion of the line is ignored, but the space leading up to it is noticed by -@code{gtroff}. This only affects the @code{.ds} and @code{.as} -request. +@code{gtroff}. This only affects the @code{ds} and @code{as} +request and its variants. -@cindex tabs before comments +@cindex tabs, before comments @cindex comments, lining up with tabs One possibly irritating idiosyncracy is that tabs must not be used to -line up comments. Tabs are not treated as white space between the +line up comments. Tabs are not treated as whitespace between the request and macro arguments. @cindex undefined request @@ -3524,7 +5039,7 @@ To avoid this, it is common to start the line with @code{.\"} which causes the line to be treated as an undefined request and thus ignored completely. -@rqindex ' +@cindex @code{'}, as a comment Another commenting scheme seen sometimes is three consecutive single quotes (@code{'''}) at the beginning of a line. This works, but @code{gtroff} gives a warning about an undefined macro (namely @@ -3612,35 +5127,40 @@ details of formatting parameters. @node Setting Registers, Interpolating Registers, Registers, Registers @subsection Setting Registers -@cindex setting registers -@cindex registers, setting +@cindex setting registers (@code{nr}, @code{\R}) +@cindex registers, setting (@code{nr}, @code{\R}) Define or set registers using the @code{nr} request or the @code{\R} escape. -@Defreq {nr, ident value} -@Defescx {\\R, ', ident value, '} +@DefreqList {nr, ident value} +@DefescListEnd {\\R, ', ident value, '} Set number register @var{ident} to @var{value}. If @var{ident} doesn't exist, @code{gtroff} creates it. The argument to @code{\R} usually has to be enclosed in quotes. @xref{Escapes}, for details on parameter delimiting characters. + +The @code{\R} escape doesn't produce an input token in @code{gtroff}; +with other words, it vanishes completely after @code{gtroff} has +processed it. @endDefreq For example, the following two lines are equivalent: @Example -.nr a 1 -\R'a 1' +.nr a (((17 + (3 * 4))) % 4) +\R'a (((17 + (3 * 4))) % 4)' + @result{} 1 @endExample Both @code{nr} and @code{\R} have two additional special forms to increment or decrement a register. -@Defreq {nr, ident @t{+}@Var{value}} -@Defreqx {nr, ident @t{-}@Var{value}} -@Defescx {\\R, ', ident @t{+}@Var{value}, '} -@Defescx {\\R, ', ident @t{-}@Var{value}, '} +@DefreqList {nr, ident @t{+}@Var{value}} +@DefreqItem {nr, ident @t{-}@Var{value}} +@DefescItem {\\R, ', ident @t{+}@Var{value}, '} +@DefescListEnd {\\R, ', ident @t{-}@Var{value}, '} Increment (decrement) register @var{ident} by @var{value}. @Example @@ -3683,16 +5203,26 @@ with a @samp{0}: @endDefreq @Defreq {rr, ident} +@cindex removing number register (@code{rr}) +@cindex number register, removing (@code{rr}) +@cindex register, removing (@code{rr}) Remove number register @var{ident}. If @var{ident} doesn't exist, the request is ignored. @endDefreq @Defreq {rnn, ident1 ident2} +@cindex renaming number register (@code{rnn}) +@cindex number register, renaming (@code{rnn}) +@cindex register, renaming (@code{rnn}) Rename number register @var{ident1} to @var{ident2}. If either @var{ident1} or @var{ident2} doesn't exist, the request is ignored. @endDefreq @Defreq {aln, ident1 ident2} +@cindex alias, number register, creating (@code{aln}) +@cindex creating alias, for number register (@code{aln}) +@cindex number register, creating alias (@code{aln}) +@cindex register, creating alias (@code{aln}) Create an alias @var{ident1} for a number register @var{ident2}. The new name and the old name are exactly equivalent. If @var{ident1} is undefined, a warning of type @samp{reg} is generated, and the request @@ -3703,23 +5233,22 @@ is ignored. @xref{Debugging}, for information about warnings. @node Interpolating Registers, Auto-increment, Setting Registers, Registers @subsection Interpolating Registers -@cindex interpolating registers -@cindex registers, interpolating +@cindex interpolating registers (@code{\n}) +@cindex registers, interpolating (@code{\n}) Numeric registers can be accessed via the @code{\n} escape. +@DefescList {\\n, , i, } +@DefescItem {\\n, @lparen{}, id, } +@DefescListEnd {\\n, @lbrack{}, ident, @rbrack} @cindex nested assignments @cindex assignments, nested @cindex indirect assignments @cindex assignments, indirect -@Defesc {\\n, , i, } -@Defescx {\\n, @lparen{}, id, } -@Defescx {\\n, @lbrack{}, ident, @rbrack} -Interpolate number register with name @var{ident} (one-character name -@var{i}, two-character name @var{id}). This means that the value of -the register is expanded in-place while @code{gtroff} is parsing the -input line. Nested assignments (also called indirect assignments) are -possible. +Interpolate number register with name @var{ident} (one-character name@w{ +}@var{i}, two-character name @var{id}). This means that the value of the +register is expanded in-place while @code{gtroff} is parsing the input line. +Nested assignments (also called indirect assignments) are possible. @Example .nr a 5 @@ -3751,8 +5280,8 @@ Number registers can also be auto-incremented and auto-decremented. The increment or decrement value can be specified with a third argument to the @code{nr} request or @code{\R} escape. -@esindex \R @Defreq {nr, ident value incr} +@cindex @code{\R}, difference to @code{nr} Set number register @var{ident} to @var{value}; the increment for auto-incrementing is set to @var{incr}. Note that the @code{\R} escape doesn't support this notation. @@ -3761,18 +5290,18 @@ escape doesn't support this notation. To activate auto-incrementing, the escape @code{\n} has a special syntax form. -@Defesc {\\n, +, i, } -@Defescx {\\n, -, i, } -@Defescx {\\n, @lparen{}+, id, } -@Defescx {\\n, @lparen{}-, id, } -@Defescx {\\n, +@lparen{}, id, } -@Defescx {\\n, -@lparen{}, id, } -@Defescx {\\n, @lbrack{}+, ident, @rbrack{}} -@Defescx {\\n, @lbrack{}-, ident, @rbrack{}} -@Defescx {\\n, +@lbrack{}, ident, @rbrack{}} -@Defescx {\\n, -@lbrack{}, ident, @rbrack{}} +@DefescList {\\n, +, i, } +@DefescItem {\\n, -, i, } +@DefescItem {\\n, @lparen{}+, id, } +@DefescItem {\\n, @lparen{}-, id, } +@DefescItem {\\n, +@lparen{}, id, } +@DefescItem {\\n, -@lparen{}, id, } +@DefescItem {\\n, @lbrack{}+, ident, @rbrack{}} +@DefescItem {\\n, @lbrack{}-, ident, @rbrack{}} +@DefescItem {\\n, +@lbrack{}, ident, @rbrack{}} +@DefescListEnd {\\n, -@lbrack{}, ident, @rbrack{}} Before interpolating, increment or decrement @var{ident} -(one-character name @var{i}, two-character name @var{id}) by the +(one-character name@w{ }@var{i}, two-character name @var{id}) by the auto-increment value as specified with the @code{nr} request (or the @code{\R} escape). If no auto-increment value has been specified, these syntax forms are identical to @code{\n}. @@ -3801,6 +5330,7 @@ produces @endExample @cindex increment value without changing the register +@cindex value, incrementing without changing the register To change the increment value without changing the value of a register (@var{a} in the example), the following can be used: @@ -3812,8 +5342,8 @@ To change the increment value without changing the value of a register @node Assigning Formats, Built-in Registers, Auto-increment, Registers @subsection Assigning Formats -@cindex assigning formats -@cindex formats, assigning +@cindex assigning formats (@code{af}) +@cindex formats, assigning (@code{af}) When a register is used in the text of an input file (as opposed to part of an expression), it is textually replaced (or interpolated) @@ -3887,19 +5417,19 @@ thousand and Roman numeral ten thousand (Unicode code points If @var{ident} doesn't exist, it is created. @cindex read-only register, changing format -@cindex changing format, read-only register +@cindex changing format, and read-only registers Changing the output format of a read-only register causes an error. It is necessary to first copy the register's value to a writeable register, then apply the @code{af} request to this other register. @endDefreq -@cindex format of register -@cindex register, format -@Defesc {\\g, , i, } -@Defescx {\\g, @lparen{}, id, } -@Defescx {\\g, @lbrack{}, ident, @rbrack{}} +@DefescList {\\g, , i, } +@DefescItem {\\g, @lparen{}, id, } +@DefescListEnd {\\g, @lbrack{}, ident, @rbrack{}} +@cindex format of register (@code{\g}) +@cindex register, format (@code{\g}) Return the current format of the specified register @var{ident} -(one-character name @var{i}, two-character name @var{id}). For +(one-character name@w{ }@var{i}, two-character name @var{id}). For example, @samp{\ga} after the previous example would produce the string @samp{000}. If the register hasn't been defined yet, nothing is returned. @@ -3915,42 +5445,73 @@ is returned. The following lists some built-in registers which are not described elsewhere in this manual. Any register which begins with a @samp{.} is read-only. A complete listing of all built-in registers can be found in -@ref{Register Index}. +appendix@w{ }@ref{Register Index}. @table @code +@item .F +@cindex current input file name register (@code{.F}) +@cindex input file name, current, register (@code{.F}) +@vindex .F +This string-valued register returns the current input file name. + @item .H -@cindex horizontal resolution register -@cindex resolution, horizontal, register +@cindex horizontal resolution register (@code{.H}) +@cindex resolution, horizontal, register (@code{.H}) @vindex .H Horizontal resolution in basic units. @item .V -@cindex vertical resolution register -@cindex resolution, vertical, register +@cindex vertical resolution register (@code{.V}) +@cindex resolution, vertical, register (@code{.V}) @vindex .V Vertical resolution in basic units. +@item seconds +@cindex seconds, current time (@code{seconds}) +@cindex time, current, seconds (@code{seconds}) +@cindex current time, seconds (@code{seconds}) +@vindex seconds +The number of seconds after the minute, normally in the range@w{ }0 +to@w{ }59, but can be up to@w{ }61 to allow for leap seconds. Initialized +at start-up of @code{gtroff}. + +@item minutes +@cindex minutes, current time (@code{minutes}) +@cindex time, current, minutes (@code{minutes}) +@cindex current time, minutes (@code{minutes}) +@vindex minutes +The number of minutes after the hour, in the range@w{ }0 to@w{ }59. +Initialized at start-up of @code{gtroff}. + +@item hours +@cindex hours, current time (@code{hours}) +@cindex time, current, hours (@code{hours}) +@cindex current time, hours (@code{hours}) +@vindex hours +The number of hours past midnight, in the range@w{ }0 to@w{ }23. +Initialized at start-up of @code{gtroff}. + @item dw -@cindex day of the week register -@cindex date, day of the week register +@cindex day of the week register (@code{dw}) +@cindex date, day of the week register (@code{dw}) @vindex dw Day of the week (1-7). @item dy -@cindex day of the month register -@cindex date, day of the month register +@cindex day of the month register (@code{dy}) +@cindex date, day of the month register (@code{dy}) @vindex dy Day of the month (1-31). @item mo -@cindex month of the year register -@cindex date, month of the year register +@cindex month of the year register (@code{mo}) +@cindex date, month of the year register (@code{mo}) @vindex mo Current month (1-12). @item year -@cindex date, year register -@cindex year, current, register +@cindex date, year register (@code{year}, @code{yr}) +@cindex year, current, register (@code{year}, @code{yr}) @vindex year The current year. @@ -3959,8 +5520,9 @@ The current year. The current year minus@w{ }1900. Unfortunately, the documentation of @acronym{UNIX} Version@w{ }7's @code{troff} had a year@w{ }2000 bug: It incorrectly claimed that @code{yr} contains the last two digits of the -year. That claim has never been true of either traditional @code{troff} -or GNU @code{troff}. Old @code{troff} input that looks like this: +year. That claim has never been true of either @acronym{AT&T} +@code{troff} or GNU @code{troff}. Old @code{troff} input that looks +like this: @Example '\" The following line stopped working after 1999 @@ -3986,17 +5548,16 @@ This document was formatted in \n(y4. @vindex .c @itemx c. @vindex c. -@cindex input line number register -@cindex line number, input, register +@cindex input line number register (@code{.c}, @code{c.}) +@cindex line number, input, register (@code{.c}, @code{c.}) The current @emph{input} line number. Register @samp{.c} is read-only, whereas @samp{c.} (a @code{gtroff} extension) is writable also, affecting both @samp{.c} and @samp{c.}. @item ln @vindex ln -@rqindex nm -@cindex output line number register -@cindex line number, output, register +@cindex output line number register (@code{ln}) +@cindex line number, output, register (@code{ln}) The current @emph{output} line number after a call to the @code{nm} request to activate line numbering. @@ -4004,33 +5565,39 @@ request to activate line numbering. @item .x @vindex .x -@cindex major version number register -@cindex version number, major, register +@cindex major version number register (@code{.x}) +@cindex version number, major, register (@code{.x}) The major version number. For example, if the version number is@w{ }1.03 then @code{.x} contains@w{ }@samp{1}. @item .y @vindex .y -@cindex minor version number register -@cindex version number, minor, register +@cindex minor version number register (@code{.y}) +@cindex version number, minor, register (@code{.y}) The minor version number. For example, if the version number is@w{ }1.03 then @code{.y} contains@w{ }@samp{03}. @item .Y @vindex .Y -@cindex revision number register +@cindex revision number register (@code{.Y}) The revision number of @code{groff}. +@item $$ +@vindex $$ +@cindex process ID of @code{gtroff} register (@code{$$}) +@cindex @code{gtroff}, process ID register (@code{$$}) +The process ID of @code{gtroff}. + @item .g @vindex .g -@cindex @code{gtroff} identification register -@cindex GNU-specific register +@cindex @code{gtroff}, identification register (@code{.g}) +@cindex GNU-specific register (@code{.g}) Always@w{ }1. Macros should use this to determine whether they are running under GNU @code{troff}. @item .A @vindex .A -@cindex @acronym{ASCII} approximation output register +@cindex @acronym{ASCII} approximation output register (@code{.A}) If the command line option @option{-a} is used to produce an @acronym{ASCII} approximation of the output, this is set to@w{ }1, zero otherwise. @xref{Groff Options}. @@ -4049,7 +5616,7 @@ number register @code{.T} is set to@w{ }1, and zero otherwise. @xref{Groff Options}. @stindex .T -@cindex output device register +@cindex output device name string register (@code{.T}) Additionally, @code{gtroff} predefines a single read-write string register @code{.T} which contains the current output device (for example, @samp{latin1} or @samp{ps}). @@ -4068,17 +5635,17 @@ example, @samp{latin1} or @samp{ps}). @cindex break @cindex line break -@rqindex bp -@rqindex ce -@rqindex cf -@rqindex fi -@rqindex fl -@rqindex in -@rqindex nf -@rqindex rj -@rqindex sp -@rqindex ti -@rqindex trf +@cindex @code{bp} request, causing implicit linebreak +@cindex @code{ce} request, causing implicit linebreak +@cindex @code{cf} request, causing implicit linebreak +@cindex @code{fi} request, causing implicit linebreak +@cindex @code{fl} request, causing implicit linebreak +@cindex @code{in} request, causing implicit linebreak +@cindex @code{nf} request, causing implicit linebreak +@cindex @code{rj} request, causing implicit linebreak +@cindex @code{sp} request, causing implicit linebreak +@cindex @code{ti} request, causing implicit linebreak +@cindex @code{trf} request, causing implicit linebreak Various ways of causing @dfn{breaks} were given in @ref{Implicit Line Breaks}. The @code{br} request likewise causes a break. Several other requests also cause breaks, but implicitly. These are @@ -4104,21 +5671,23 @@ Initially, @code{gtroff} fills and adjusts text to both margins. Filling can be disabled via the @code{nf} request and re-enabled with the @code{fi} request. -@cindex fill mode -@cindex mode, fill -@Defreq {fi, } -@Defregx {.u} +@DefreqList {fi, } +@DefregListEnd {.u} +@cindex fill mode (@code{fi}) +@cindex mode, fill (@code{fi}) Activate fill mode (which is the default). This request implicitly enables adjusting; it also inserts a break in the text currently being filled. The read-only number register @code{.u} is set to@w{ }1. The fill mode status is associated with the current environment (@pxref{Environments}). + +See @ref{Line Control}, for interaction with the @code{\c} escape. @endDefreq -@cindex no-fill mode -@cindex mode, no-fill @Defreq {nf, } +@cindex no-fill mode (@code{nf}) +@cindex mode, no-fill (@code{nf}) Activate no-fill mode. Input lines are output as-is, retaining line breaks and ignoring the current line length. This command implicitly disables adjusting; it also causes a break. The number register @@ -4126,10 +5695,12 @@ disables adjusting; it also causes a break. The number register The fill mode status is associated with the current environment (@pxref{Environments}). + +See @ref{Line Control}, for interaction with the @code{\c} escape. @endDefreq -@Defreq {ad, [@Var{mode}]} -@Defregx {.j} +@DefreqList {ad, [@Var{mode}]} +@DefregListEnd {.j} Set adjusting mode. Activation and deactivation of adjusting is done implicitly with @@ -4149,7 +5720,7 @@ Adjust text to the right margin, producing ragged-left text. @item c @cindex centered text -@rqindex ce +@cindex @code{ce} request, difference to @samp{.ad@w{ }c} Center filled text. This is different to the @code{ce} request which only centers text without filling. @@ -4174,7 +5745,7 @@ text text @endExample -@cindex current adjustment mode register +@cindex adjustment mode register (@code{.j}) The current adjustment mode is available in the read-only number register @code{.j}; it can be stored and subsequently used to set adjustment. @@ -4192,10 +5763,11 @@ The adjustment mode status is associated with the current environment (@pxref{Environments}). @endDefreq -@Defesc {\\p, , , } +@DefreqList {brp, } +@DefescListEnd {\\p, , , } Adjust the current line and cause a break. -In most cases this produces very ugly results, since @code{gtroff} +In most cases this produces very ugly results since @code{gtroff} doesn't have a sophisticated paragraph building algorithm (as @TeX{} have, for example); instead, @code{gtroff} fills and adjusts a paragraph line by line: @@ -4214,17 +5786,17 @@ is formatted as uninteresting sentence. This is an uninteresting sentence. @endExample -@endDefesc +@endDefreq -@cindex word space size -@cindex size of word space -@cindex space between words -@cindex sentence space size -@cindex size of sentence space -@cindex space between sentences -@Defreq {ss, word_space_size [@Var{sentence_space_size}]} -@Defregx {.ss} -@Defregx {.sss} +@DefreqList {ss, word_space_size [@Var{sentence_space_size}]} +@DefregItem {.ss} +@DefregListEnd {.sss} +@cindex word space size register (@code{.ss}) +@cindex size of word space register (@code{.ss}) +@cindex space between words register (@code{.ss}) +@cindex sentence space size register (@code{.sss}) +@cindex size of sentence space register (@code{.sss}) +@cindex space between sentences register (@code{.sss}) Change the minimum size of a space between filled words. It takes its units as one twelfth of the space width parameter for the current font. Initially both the @var{word_space_size} and @@ -4252,22 +5824,22 @@ values of the parameters set by the first and second arguments of the The word space and sentence space values are associated with the current environment (@pxref{Environments}). -Contrary to traditional Unix @code{troff}, this request is @emph{not} -ignored if a tty output device is used; the given values are then -rounded down to a multiple of@w{ }12. - -@c XXX xref implementation differences +Contrary to @acronym{AT&T} @code{troff}, this request is @emph{not} +ignored if a TTY output device is used; the given values are then +rounded down to a multiple of@w{ }12 (@pxref{Implementation Differences}). The request is ignored if there is no parameter. @endDefreq -@cindex centering lines -@cindex lines, centering -@Defreq {ce, [@Var{nnn}]} -@Defregx {.ce} +@DefreqList {ce, [@Var{nnn}]} +@DefregListEnd {.ce} +@cindex centering lines (@code{ce}) +@cindex lines, centering (@code{ce}) Center text. While the @w{@samp{.ad c}} request also centers text, it fills the text as well. @code{ce} does not fill the -text it affects. This request causes a break. +text it affects. This request causes a break. The number of lines +still to be centered is associated with the current environment +(@pxref{Environments}). The following example demonstrates the differences. Here the input: @@ -4301,9 +5873,6 @@ With no arguments, @code{ce} centers the next line of text. @var{nnn} specifies the number of lines to be centered. If the argument is zero or negative, centering is disabled. -@rqindex ll -@rqindex in -@rqindex ti The basic length for centering text is the line length (as set with the @code{ll} request) minus the indentation (as set with the @code{in} request). Temporary indentation is ignored. @@ -4317,15 +5886,17 @@ The @code{.ce} read-only number register contains the number of lines remaining to be centered, as set by the @code{ce} request. @endDefreq -@cindex justifying text -@cindex text, justifying -@cindex right-justifying -@Defreq {rj, [@Var{nnn}]} -@Defregx {.rj} +@DefreqList {rj, [@Var{nnn}]} +@DefregListEnd {.rj} +@cindex justifying text (@code{rj}) +@cindex text, justifying (@code{rj}) +@cindex right-justifying (@code{rj}) Justify unfilled text to the right margin. Arguments are identical to the @code{ce} request. The @code{.rj} read-only number register is the number of lines to be right-justified as set by the @code{rj} -request. This request causes a break. +request. This request causes a break. The number of lines still to be +right-justified is associated with the current environment +(@pxref{Environments}). @endDefreq @@ -4339,8 +5910,8 @@ request. This request causes a break. As discussed in @ref{Hyphenation}, @code{gtroff} hyphenates words. There are a number of ways to influence hyphenation. -@Defreq {hy, [@Var{mode}]} -@Defregx {.hy} +@DefreqList {hy, [@Var{mode}]} +@DefregListEnd {.hy} Enable hyphenation. The request has an optional numeric argument, @var{mode}, to restrict hyphenation if necessary: @@ -4363,7 +5934,7 @@ Values in the previous table are additive. For example, the value@w{ }12 causes @code{gtroff} to neither hyphenate the last two nor the first two characters of a word. -@cindex hyphenation restrictions register +@cindex hyphenation restrictions register (@code{.hy}) The current hyphenation restrictions can be found in the read-only number register @samp{.hy}. @@ -4380,15 +5951,14 @@ The hyphenation mode is associated with the current environment (@pxref{Environments}). @endDefreq -@esindex \% -@cindex explicit hyphens -@cindex hyphen, explicit -@cindex consecutive hyphenated lines -@cindex lines, consecutive hyphenated -@cindex hyphenated lines, consecutive -@Defreq {hlm, [@Var{nnn}]} -@Defregx {.hlm} -@Defregx {.hlc} +@DefreqList {hlm, [@Var{nnn}]} +@DefregItem {.hlm} +@DefregListEnd {.hlc} +@cindex explicit hyphen (@code{\%}) +@cindex hyphen, explicit (@code{\%}) +@cindex consecutive hyphenated lines (@code{hlm}) +@cindex lines, consecutive hyphenated (@code{hlm}) +@cindex hyphenated lines, consecutive (@code{hlm}) Set the maximum number of consecutive hyphenated lines to @var{nnn}. If this number is negative, there is no maximum. The default value is@w{ }@minus{}1 if @var{nnn} is omitted. This value is associated @@ -4429,11 +5999,18 @@ store such information; fortunately, with @code{gtroff}, this is no longer a restriction. @endDefreq -@cindex hyphenation character -@cindex character, hyphenation -@cindex disabling hyphenation -@cindex hyphenation, disabling -@Defesc {\\%, , , } +@DefescList {\\%, , , } +@deffnx Escape @t{\:} +@ifnotinfo +@esindex \: +@end ifnotinfo +@ifinfo +@esindex @r{<colon>} +@end ifinfo +@cindex hyphenation character (@code{\%}) +@cindex character, hyphenation (@code{\%}) +@cindex disabling hyphenation (@code{\%}) +@cindex hyphenation, disabling (@code{\%}) To tell @code{gtroff} how to hyphenate words on the fly, use the @code{\%} escape, also known as the @dfn{hyphenation character}. Preceding a word with this character prevents it from being @@ -4442,6 +6019,22 @@ the word may be hyphenated at that point. Note that this mechanism only affects that one occurrence of the word; to change the hyphenation of a word for the entire document, use the @code{hw} request. + +The @code{\:} escape inserts a zero-width break point +(that is, the word breaks but without adding a hyphen). + +@Example +... check the /var/log/\:httpd/\:access_log file ... +@endExample + +@cindex @code{\X}, followed by @code{\%} +@cindex @code{\Y}, followed by @code{\%} +@cindex @code{\%}, following @code{\X} or @code{\Y} +Note that @code{\X} and @code{\Y} start a word, that is, the @code{\%} +escape in (say) @w{@samp{ \X'...'\%foobar}} and +@w{@samp{ \Y'...'\%foobar}} no longer prevents hyphenation but inserts +a hyphenation point at the beginning of @samp{foobar}; most likely +this isn't what you want to do. @endDefesc @Defreq {hc, [@Var{char}]} @@ -4454,23 +6047,66 @@ The hyphenation character is associated with the current environment (@pxref{Environments}). @endDefreq -@cindex hyphenation patterns -@cindex patterns for hyphenation -@Defreq {hpf, pattern_file} +@DefreqList {hpf, pattern_file} +@DefreqItem {hpfa, pattern_file} +@DefreqListEnd {hpfcode, a b [c d @dots{}]} +@cindex hyphenation patterns (@code{hpf}) +@cindex patterns for hyphenation (@code{hpf}) Read in a file of hyphenation patterns. This file is searched for in the same way as @file{@var{name}.tmac} (or @file{tmac.@var{name}}) is searched for if the @option{-m@var{name}} option is specified. -It should have the same format as the argument to the @code{\patterns} -primitive in @TeX{} (without using @TeX{}'s macro expansion); the -letters appearing in this file are interpreted as hyphenation codes. A -@samp{%} character in the patterns file introduces a comment that -continues to the end of the line. +It should have the same format as (simple) @TeX{} patterns files. +More specifically, the following scanning rules are implemented. + +@itemize @bullet +@item +A percent sign starts a comment (up to the end of the line) +even if preceded by a backslash. + +@item +No support for `digraphs' like @code{\$}. + +@item +@code{^^@var{xx}} (@var{x} is 0-9 or a-f) and @code{^^@var{x}} (character +code of @var{x} in the range 0-127) are recognized; other use of @code{^} +causes an error. + +@item +No macro expansion. + +@item +@code{hpf} checks for the expression @code{\patterns@{@dots{}@}} +(possibly with whitespace before and after the braces). +Everything between the braces is taken as hyphenation patterns. +Consequently, @code{@{} and @code{@}} are not allowed in patterns. + +@item +Similarly, @code{\hyphenation@{@dots{}@}} gives a list of hyphenation +exceptions. + +@item +@code{\endinput} is recognized also. + +@item +For backwards compatibility, if @code{\patterns} is missing, +the whole file is treated as a list of hyphenation patterns +(only recognizing the @code{%} character as the start of a comment). +@end itemize If no @code{hpf} request is specified (either in the document or in a macro package), @code{gtroff} won't hyphenate at all. -@rqindex hla +The @code{hpfa} request appends a file of patterns to the current list. + +The @code{hpfcode} request defines mapping values for character codes in +hyphenation patterns. @code{hpf} or @code{hpfa} then apply the mapping +(after reading the patterns) before replacing or appending them to +the current list of patterns. Its arguments are pairs of character codes +-- integers from 0 to@w{ }255. The request maps character code@w{ }@var{a} +to code@w{ }@var{b}, code@w{ }@var{c} to code@w{ }@var{d}, and so on. You +can use character codes which would be invalid otherwise. + @pindex troffrc @pindex troffrc-end @pindex hyphen.us @@ -4480,76 +6116,81 @@ invoked by the @file{troffrc} or @file{troffrc-end} file; by default, @file{troffrc} loads hyphenation patterns for American English (in file @file{hyphen.us}). +A second call to @code{hpf} (for the same language) will replace the +hyphenation patterns with the new ones. + Invoking @code{hpf} causes an error if there is no current hyphenation language. @endDefreq -@cindex hyphenation code -@cindex code, hyphenation @Defreq {hcode, c1 code1 c2 code2 @dots{}} +@cindex hyphenation code (@code{hcode}) +@cindex code, hyphenation (@code{hcode}) Set the hyphenation code of character @var{c1} to @var{code1}, that of @var{c2} to @var{code2}, etc. A hyphenation code must be a single input character (not a special character) other than a digit or a space. Initially each lower-case letter (@samp{a}-@samp{z}) has its -hyphenation set to itself, and each upper-case letter +hyphenation code set to itself, and each upper-case letter (@samp{A}-@samp{Z}) has a hyphenation code which is the lower-case version of itself. This request is ignored if it has no parameter. @endDefreq -@cindex hyphenation margin -@cindex margin for hyphenation -@rqindex ad -@Defreq {hym, [@Var{length}]} -@Defregx {.hym} +@DefreqList {hym, [@Var{length}]} +@DefregListEnd {.hym} +@cindex hyphenation margin (@code{hym}) +@cindex margin for hyphenation (@code{hym}) +@cindex @code{ad} request, and hyphenation margin Set the (right) hyphenation margin to @var{length}. If the current -adjustment mode is not @samp{b} or@w{ }@samp{n}, the line is not +adjustment mode is not @samp{b} or @samp{n}, the line is not hyphenated if it is shorter than @var{length}. Without an argument, the hyphenation margin is reset to its default value, which is@w{ }0. -The default scaling indicator for this request is@w{ }@code{m}. The +The default scaling indicator for this request is @samp{m}. The hyphenation margin is associated with the current environment (@pxref{Environments}). A negative argument resets the hyphenation margin to zero, emitting a warning of type @samp{range}. -@cindex current hyphenation margin register +@cindex hyphenation margin register (@code{.hym}) The current hyphenation margin is available in the @code{.hym} read-only number register. @endDefreq -@cindex hyphenation space -@rqindex ad -@Defreq {hys, [@Var{hyphenation_space}]} -@Defregx {.hys} +@DefreqList {hys, [@Var{hyphenation_space}]} +@DefregListEnd {.hys} +@cindex hyphenation space (@code{hys}) +@cindex @code{ad} request, and hyphenation space Set the hyphenation space to @var{hyphenation_space}. If the current -adjustment mode is @samp{b} or@w{ }@samp{n}, don't hyphenate the line +adjustment mode is @samp{b} or @samp{n}, don't hyphenate the line if it can be justified by adding no more than @var{hyphenation_space} extra space to each word space. Without argument, the hyphenation space is set to its default value, which is@w{ }0. The default -scaling indicator for this request is@w{ }@code{m}. The hyphenation +scaling indicator for this request is @samp{m}. The hyphenation space is associated with the current environment (@pxref{Environments}). A negative argument resets the hyphenation space to zero, emitting a warning of type @samp{range}. -@cindex current hyphenation space register +@cindex hyphenation space register (@code{.hys}) The current hyphenation space is available in the @code{.hys} read-only number register. @endDefreq -@cindex soft hyphen character -@cindex character, soft hyphen -@glindex hy -@rqindex char -@rqindex tr -@Defreq {shc, [@Var{char}]} -Set the soft hyphen character to @var{char}. If the argument is -omitted, the soft hyphen character is set to the default character -@code{\(hy} (this is the start-up value of @code{gtroff} also). The -soft hyphen character is the character that is inserted when a word is +@Defreq {shc, [@Var{glyph}]} +@cindex soft hyphen character, setting (@code{shc}) +@cindex character, soft hyphen, setting (@code{shc}) +@cindex glyph, soft hyphen (@code{hy}) +@cindex soft hyphen glyph (@code{hy}) +@cindex @code{char} request, and soft hyphen character +@cindex @code{tr} request, and soft hyphen character +Set the @dfn{soft hyphen character} to @var{glyph}.@footnote{@dfn{Soft +hyphen character} is a misnomer since it is an output glyph.} If the +argument is omitted, the soft hyphen character is set to the default +glyph @code{\(hy} (this is the start-up value of @code{gtroff} also). +The soft hyphen character is the glyph that is inserted when a word is hyphenated at a line break. If the soft hyphen character does not exist in the font of the character immediately preceding a potential break point, then the line is not broken at that point. Neither @@ -4558,21 +6199,21 @@ definitions (specified with the @code{char} request) nor translations soft hyphen character. @endDefreq -@rqindex hpf -@rqindex hw +@DefreqList {hla, language} +@DefregListEnd {.hla} +@cindex @code{hpf} request, and hyphenation language +@cindex @code{hw} request, and hyphenation language @pindex troffrc @pindex troffrc-end -@Defreq {hla, language} -@Defregx {.hla} Set the current hyphenation language to the string @var{language}. Hyphenation exceptions specified with the @code{hw} request and -hyphenation patterns specified with the @code{hpf} request are both -associated with the current hyphenation language. The @code{hla} -request is usually invoked by the @file{troffrc} or the +hyphenation patterns specified with the @code{hpf} and @code{hpfa} +requests are both associated with the current hyphenation language. +The @code{hla} request is usually invoked by the @file{troffrc} or the @file{troffrc-end} files; @file{troffrc} sets the default language to @samp{us}. -@cindex current hyphenation language register +@cindex hyphenation language register (@code{.hla}) The current hyphenation language is available as a string in the read-only number register @samp{.hla}. @@ -4596,13 +6237,12 @@ Space downwards @var{distance}. With no argument it advances 1@w{ }line. A negative argument causes @code{gtroff} to move up the page the specified distance. If the argument is preceded by a @samp{|} then @code{gtroff} moves that distance from the top of the page. This -request causes a line break. The default scaling indicator is@w{ -}@code{v}. +request causes a line break. The default scaling indicator is @samp{v}. @endDefreq -@cindex double-spacing -@Defreq {ls, [@Var{nnn}]} -@Defregx {.L} +@DefreqList {ls, [@Var{nnn}]} +@DefregListEnd {.L} +@cindex double-spacing (@code{ls}) Output @w{@var{nnn}@minus{}1} blank lines after each line of text. With no argument, @code{gtroff} uses the previous value before the last @code{ls} call. @@ -4610,70 +6250,86 @@ last @code{ls} call. @Example .ls 2 \" This causes double-spaced output .ls 3 \" This causes triple-spaced output -.ls \" Again double spaced +.ls \" Again double-spaced @endExample The line spacing is associated with the current environment (@pxref{Environments}). -@cindex current line spacing register +@cindex line spacing register (@code{.L}) The read-only number register @code{.L} contains the current line spacing setting. @endDefreq -@c XXX document \n[nl] -@c XXX document \n[nl] == -1 if vertical position is zero +@xref{Changing Type Sizes}, for the requests @code{vs} and @code{pvs} +as alternatives to @code{ls}. -@Defesc {\\x, ', spacing, '} -@Defregx {.a} +@DefescList {\\x, ', spacing, '} +@DefregListEnd {.a} Sometimes, extra vertical spacing is only needed occasionally, e.g.@: to allow space for a tall construct (like an equation). The @code{\x} escape does this. The escape is given a numerical argument, usually enclosed in quotes (like @samp{\x'3p'}); the default scaling indicator -is@w{ }@code{v}. If this number is positive extra vertical space is +is @samp{v}. If this number is positive extra vertical space is inserted below the current line. A negative number adds space above. If this escape is used multiple times on the same line, the maximum of the values is used. @xref{Escapes}, for details on parameter delimiting characters. -@cindex extra vertical line space register +@cindex extra post-vertical line space register (@code{.a}) The @code{.a} read-only number register contains the most recent (nonnegative) extra vertical line space. -@c XXX -@ignore +Using @code{\x} can be necessary in combination with the @code{\b} +escape, as the following example shows. + @Example -... example of inline equation ... +This is a test with the \[rs]b escape. +.br +This is a test with the \[rs]b escape. +.br +This is a test with \b'xyz'\x'-1m'\x'1m'. +.br +This is a test with the \[rs]b escape. +.br +This is a test with the \[rs]b escape. +@endExample + +@noindent +produces + +@Example +This is a test with the \b escape. +This is a test with the \b escape. + x +This is a test with y. + z +This is a test with the \b escape. +This is a test with the \b escape. @endExample -@end ignore @endDefesc -@rqindex sp -@cindex no-space mode -@cindex mode, no-space +@DefreqList {ns, } +@DefreqItem {rs, } +@DefregListEnd {.ns} +@cindex @code{sp} request, and no-space mode +@cindex no-space mode (@code{ns}) +@cindex mode, no-space (@code{ns}) @cindex blank lines, disabling @cindex lines, blank, disabling -@Defreq {ns, } -@Defregx {.ns} Enable @dfn{no-space mode}. In this mode, spacing (either via @code{sp} or via blank lines) is disabled. The @code{bp} request to advance to the next page is also disabled, except if it is accompanied by a page number (see @ref{Page Control}, for more information). This mode ends when actual text is output or the @code{rs} request is -encountered. The read-only number register @code{.ns} is set to@w{ }1. - -This request is useful for macros which want to avoid that subsequent -macros inadvertently insert some vertical space before the text starts -(for example, to set up the first paragraph after a section header). - -@c XXX xref -@endDefreq - -@Defreq {rs, } -Disable no-space mode. +encountered which ends no-space mode. The read-only number register +@code{.ns} is set to@w{ }1 as long as no-space mode is active. -@c XXX xref +This request is useful for macros that conditionally +insert vertical space before the text starts +(for example, a paragraph macro could insert some space +except when it is the first paragraph after a section header). @endDefreq @@ -4681,8 +6337,8 @@ Disable no-space mode. @node Tabs and Fields, Character Translations, Manipulating Spacing, gtroff Reference @section Tabs and Fields -@cindex tabs and fields -@cindex fields and tabs +@cindex tabs, and fields +@cindex fields, and tabs @cindex @acronym{EBCDIC} encoding of a tab A tab character (@acronym{ASCII} char@w{ }9, @acronym{EBCDIC} char@w{ @@ -4690,12 +6346,14 @@ A tab character (@acronym{ASCII} char@w{ }9, @acronym{EBCDIC} char@w{ like it did on a typewriter). @Defesc {\\t, , , } +@cindex tab character, non-interpreted (@code{\t}) +@cindex character, tab, non-interpreted (@code{\t}) This escape is a non-interpreted tab character. In copy mode (@pxref{Copy-in Mode}), @code{\t} is the same as a real tab character. @endDefesc -@Defreq {ta, [@Var{n1} @Var{n2} @dots{} @Var{nn} @t{T} @Var{r1} @Var{r2} @dots{} @Var{rn}]} -@Defregx {.tabs} +@DefreqList {ta, [@Var{n1} @Var{n2} @dots{} @Var{nn} @t{T} @Var{r1} @Var{r2} @dots{} @Var{rn}]} +@DefregListEnd {.tabs} Change tab stop positions. This request takes a series of tab specifiers as arguments (optionally divided into two groups with the letter @samp{T}) which indicate where each tab stop is to be @@ -4743,7 +6401,7 @@ is specified by appending @samp{R}, @samp{L}, or @samp{C} to the tab specifier. The default justification is @samp{L}. Example: @Example -.ta 1i 2iC 2iR +.ta 1i 2iC 3iR @endExample Some notes: @@ -4821,15 +6479,13 @@ Tab stops are associated with the current environment Calling @code{ta} without an argument removes all tab stops. @item -@cindex tab stops, for tty output devices -The start-up value of @code{gtroff} is @w{@samp{T 0.5i}}. This value -is used even for tty output devices (contrary to @acronym{UNIX} -@code{nroff} which has tab stops preset every 0.8@dmn{i}). - -@c XXX xref implementation differences +@cindex tab stops, for TTY output devices +The start-up value of @code{gtroff} is @w{@samp{T 0.5i}} in troff mode +and @w{@samp{T 0.8i}} in nroff mode (the latter is done with an +explicit call to the @code{ta} request in the file @file{tty.tmac}. @end itemize -@cindex current tab settings register +@cindex tab settings register (@code{.tabs}) The read-only number register @code{.tabs} contains a string representation of the current tab settings suitable for use as an argument to the @code{ta} request. @@ -4839,16 +6495,65 @@ argument to the @code{ta} request. \*[tab-string] @result{} T120u @endExample + +@cindex @code{.S} register, Plan@w{ }9 alias for @code{.tabs} +@cindex @code{.tabs} register, Plan@w{ }9 alias (@code{.S}) +The @code{troff} version of the Plan@w{ }9 operating system uses +register @code{.S} for the same purpose. @endDefreq -@cindex tab repetition character -@cindex character, tab repetition -@Defreq {tc, [@Var{fill-char}]} +@Defreq {tc, [@Var{fill-glyph}]} +@cindex tab repetition character (@code{tc}) +@cindex character, tab repetition (@code{tc}) +@cindex glyph, tab repetition (@code{tc}) Normally @code{gtroff} fills the space to the next tab stop with whitespace. This can be changed with the @code{tc} request. With no argument @code{gtroff} reverts to using whitespace, which is the -default. The value of this @dfn{tab repetition} character is -associated with the current environment (@pxref{Environments}). +default. The value of this @dfn{tab repetition character} is +associated with the current environment +(@pxref{Environments}).@footnote{@dfn{Tab repetition character} is a +misnomer since it is an output glyph.} +@endDefreq + +@DefreqList {linetabs, n} +@DefregListEnd {.linetabs} +@cindex tab, line-tabs mode +@cindex line-tabs mode +@cindex mode, line-tabs +If @var{n} is missing or not zero, enable @dfn{line-tabs} mode, +or disable it otherwise (the default). +In line-tabs mode, @code{gtroff} computes tab distances +relative to the (current) output line instead of the input line. + +For example, the following code: + +@Example +.ds x a\t\c +.ds y b\t\c +.ds z c +.ta 1i 3i +\*x +\*y +\*z +@endExample + +@noindent +in normal mode, results in the output + +@Example +a b c +@endExample + +@noindent +in line-tabs mode, the same code outputs + +@Example +a b c +@endExample + +Line-tabs mode is associated with the current environment. +The read-only register @code{.linetabs} is set to@w{ }1 if in line-tabs +mode, and 0 in normal mode. @endDefreq @menu @@ -4863,7 +6568,7 @@ associated with the current environment (@pxref{Environments}). @cindex leaders Sometimes it may may be desirable to use the @code{tc} request to fill a -particular tab stop with a given character (for example dots in a table +particular tab stop with a given glyph (for example dots in a table of contents), but also normal tab stops on the rest of the line. For this @code{gtroff} provides an alternate tab mechanism, called @dfn{leaders} which does just that. @@ -4871,23 +6576,27 @@ this @code{gtroff} provides an alternate tab mechanism, called @cindex leader character A leader character (character code@w{ }1) behaves similarly to a tab character: It moves to the next tab stop. The only difference is that -for this movement, the fill character defaults to a period character and +for this movement, the fill glyph defaults to a period character and not to space. @Defesc {\\a, , , } +@cindex leader character, non-interpreted (@code{\a}) +@cindex character, leader, non-interpreted (@code{\a}) This escape is a non-interpreted leader character. In copy mode (@pxref{Copy-in Mode}), @code{\a} is the same as a real leader character. @endDefesc -@cindex leader repetition character -@cindex character, leader repetition -@Defreq {lc, [@Var{fill-char}]} -Declare the leader character. Without an argument, leaders act the -same as tabs (i.e., using whitespace for filling). @code{gtroff}'s -start-up value is @samp{.}. The value of this @dfn{leader repetition} -character is associated with the current environment -(@pxref{Environments}). +@Defreq {lc, [@Var{fill-glyph}]} +@cindex leader repetition character (@code{lc}) +@cindex character, leader repetition (@code{lc}) +@cindex glyph, leader repetition (@code{lc}) +Declare the @dfn{leader repetition character}.@footnote{@dfn{Leader +repetition character} is a misnomer since it is an output glyph.} +Without an argument, leaders act the same as tabs (i.e., using +whitespace for filling). @code{gtroff}'s start-up value is a dot +(@samp{.}). The value of the leader repetition character is +associated with the current environment (@pxref{Environments}). @endDefreq @cindex table of contents @@ -4917,12 +6626,12 @@ This produces @subsection Fields @cindex fields -@cindex field delimiting character -@cindex delimiting character for fields -@cindex character, field delimiting -@cindex field padding character -@cindex padding character for fields -@cindex character, field padding +@cindex field delimiting character (@code{fc}) +@cindex delimiting character, for fields (@code{fc}) +@cindex character, field delimiting (@code{fc}) +@cindex field padding character (@code{fc}) +@cindex padding character, for fields (@code{fc}) +@cindex character, field padding (@code{fc}) @dfn{Fields} are a more general way of laying out tabular data. A field is defined as the data between a pair of @dfn{delimiting characters}. It contains substrings which are separated by @dfn{padding characters}. @@ -4939,8 +6648,8 @@ Define a delimiting and a padding character for fields. If the latter is missing, the padding character defaults to a space character. If there is no argument at all, the field mechanism is disabled (which is the default). Note that contrary to e.g.@: the tab repetition -character, delimiting and padding characters are not associated to the -current environment (@pxref{Environments}). +character, delimiting and padding characters are @emph{not} associated +to the current environment (@pxref{Environments}). Example: @@ -4969,33 +6678,32 @@ foo bar smurf @cindex character translations @cindex translations of characters -@rqindex . -@rqindex ' -@cindex control character -@cindex character, control -@cindex no-break control character -@cindex character, no-break control -@cindex control character, no-break +@cindex control character, changing (@code{cc}) +@cindex character, control, changing (@code{cc}) +@cindex no-break control character, changing (@code{c2}) +@cindex character, no-break control, changing (@code{c2}) +@cindex control character, no-break, changing (@code{c2}) The control character (@samp{.}) and the no-break control character (@samp{'}) can be changed with the @code{cc} and @code{c2} requests, respectively. @Defreq {cc, [@Var{c}]} -Set the control character to @var{c}. With no argument the default +Set the control character to@w{ }@var{c}. With no argument the default control character @samp{.} is restored. The value of the control character is associated with the current environment (@pxref{Environments}). @endDefreq @Defreq {c2, [@Var{c}]} -Set the no-break control character to @var{c}. With no argument the +Set the no-break control character to@w{ }@var{c}. With no argument the default control character @samp{'} is restored. The value of the no-break control character is associated with the current environment (@pxref{Environments}). @endDefreq -@esindex \\ @Defreq {eo, } +@cindex disabling @code{\} (@code{eo}) +@cindex @code{\}, disabling (@code{eo}) Disable the escape mechanism completely. After executing this request, the backslash character @samp{\} no longer starts an escape sequence. @@ -5021,92 +6729,191 @@ necessary then to double the escape character. Here an example: @endExample @endDefreq -@cindex escape character -@cindex character, escape @Defreq {ec, [@Var{c}]} -Set the escape character to @var{c}. With no argument the default +@cindex escape character, changing (@code{ec}) +@cindex character, escape, changing (@code{ec}) +Set the escape character to@w{ }@var{c}. With no argument the default escape character @samp{\} is restored. It can be also used to re-enable the escape mechanism after an @code{eo} request. Note that changing the escape character globally will likely break -macro packages since @code{gtroff} has no mechanism (like @TeX{}) to -`intern' macros, i.e., to convert a macro definition into an internal -form which is independent of its representation. If a macro is -called, it is executed literally. +macro packages since @code{gtroff} has no mechanism to `intern' macros, +i.e., to convert a macro definition into an internal form which is +independent of its representation (@TeX{} has this mechanism). +If a macro is called, it is executed literally. +@endDefreq + +@DefreqList {ecs, } +@DefreqListEnd {ecr, } +The @code{ecs} request saves the current escape character +in an internal register. +Use this request in combination with the @code{ec} request to +temporarily change the escape character. + +The @code{ecr} request restores the escape character +saved with @code{ecs}. +Without a previous call to @code{ecs}, this request +sets the escape character to @code{\}. @endDefreq -@Defesc {\\e, , , } -This escape sequence prints the current escape character (which is the -backslash character @samp{\} by default). +@DefescList {\\\\, , , } +@DefescItem {\\e, , , } +@DefescListEnd {\\E, , , } +Print the current escape character (which is the backslash character +@samp{\} by default). + +@code{\\} is a `delayed' backslash; more precisely, it is the default +escape character followed by a backslash, which no longer has special +meaning due to the leading escape character. It is @emph{not} an escape +sequence in the usual sense! In any unknown escape sequence +@code{\@var{X}} the escape character is ignored and @var{X} is printed. +But if @var{X} is equal to the current escape character, no warning is +emitted. + +As a consequence, only at top-level or in a diversion a backslash glyph is +printed; in copy-in mode, it expands to a single backslash which then +combines with the following character to an escape sequence. + +The @code{\E} escape differs from @code{\e} by printing an escape +character that is not interpreted in copy mode. +Use this to define strings with escapes that work +when used in copy mode (for example, as a macro argument). +The following example defines strings to begin and end +a superscript: + +@Example +.ds @{ \v'-.3m'\s'\Es[.s]*60/100' +.ds @} \s0\v'.3m' +@endExample + +Another example to demonstrate the differences between the various escape +sequences, using a strange escape character, @samp{-}. + +@Example +.ec - +.de xxx +--A'123' +.. +.xxx + @result{} -A'foo' +@endExample + +@noindent +The result is surprising for most users, expecting @samp{1} since +@samp{foo} is a valid identifier. What has happened? As mentioned +above, the leading escape character makes the following character +ordinary. Written with the default escape character the sequence +@samp{--} becomes @samp{\-} -- this is the minus sign. + +If the escape character followed by itself is a valid escape sequence, +only @code{\E} yields the expected result: + +@Example +.ec - +.de xxx +-EA'123' +.. +.xxx + @result{} 1 +@endExample @endDefesc -A @dfn{translation} is a mapping of an input character to an output -character. The default mappings are given in the font definition files -for the specific output device (@pxref{Font Files}); all mappings (both -with @code{tr} and in the font definition files) occur at output time, -i.e., the input character gets assigned the metric information of the -mapped output character. +@Defesc {\\., , , } +Similar to @code{\\}, the sequence @code{\.} isn't a real escape sequence. +As before, a warning message is suppressed if the escape character is +followed by a dot, and the dot itself is printed. -@Defreq {tr, @Var{a}@Var{b}@Var{c}@Var{d}@dots{}} -Translate character @var{a} to @var{b}, character @var{c} to @var{d}, -etc. If there is an odd number of arguments, the last one is -translated to the space character. +@Example +.de foo +. nop foo +. +. de bar +. nop bar +\\.. +. +.. +.foo +.bar + @result{} foo bar +@endExample + +@noindent +The first backslash is consumed while the macro is read, and the second +is swallowed while exexuting macro @code{foo}. +@endDefesc + +A @dfn{translation} is a mapping of an input character to an output +glyph. The mapping occurs at output time, i.e., the input character +gets assigned the metric information of the mapped output character +right before input tokens are converted to nodes (@pxref{Gtroff +Internals}, for more on this process). + +@DefreqList {tr, @Var{a}@Var{b}@Var{c}@Var{d}@dots{}} +@DefreqListEnd {trin, @Var{a}@Var{b}@Var{c}@Var{d}@dots{}} +Translate character @var{a} to glyph@w{ }@var{b}, character @var{c} to +glyph@w{ }@var{d}, etc. If there is an odd number of arguments, the +last one is translated to an unstretchable space (@w{@samp{\ }}). + +The @code{trin} request is identical to @code{tr}, +but when you unformat a diversion with @code{asciify} +it ignores the translation. +@xref{Diversions}, for details about the @code{asciify} request. Some notes: @itemize @bullet @item -@esindex \( -@esindex \[ -@esindex \' -@esindex \` -@esindex \- -@esindex \_ -@esindex \C -@esindex \N -@rqindex char -@cindex special character +@cindex @code{\(}, and translations +@cindex @code{\[}, and translations +@cindex @code{\'}, and translations +@cindex @code{\`}, and translations +@cindex @code{\-}, and translations +@cindex @code{\_}, and translations +@cindex @code{\C}, and translations +@cindex @code{\N}, and translations +@cindex @code{char} request, and translations +@cindex special characters @cindex character, special -@cindex numbered character -@cindex character, numbered +@cindex numbered glyph (@code{\N}) +@cindex glyph, numbered (@code{\N}) Special characters (@code{\(@var{xx}}, @code{\[@var{xxx}]}, @code{\C'@var{xxx}'}, @code{\'}, @code{\`}, @code{\-}, @code{\_}), -characters defined with the @code{char} request, and numbered characters +glyphs defined with the @code{char} request, and numbered glyphs (@code{\N'@var{xxx}'}) can be translated also. @item -@esindex \e +@cindex @code{\e}, and translations The @code{\e} escape can be translated also. @item -@esindex \% -@esindex \~ +@cindex @code{\%}, and translations +@cindex @code{\~}, and translations Characters can be mapped onto the @code{\%} and @code{\~} escapes (but -@code{\%} and @code{\~} can't be mapped onto another character). +@code{\%} and @code{\~} can't be mapped onto another glyph). @item -@cindex backspace character -@cindex character, backspace -@cindex leader character -@cindex character, leader -@cindex newline character -@cindex character, newline -@cindex tab character -@cindex character, tab -@esindex \a -@esindex \t +@cindex backspace character, and translations +@cindex character, backspace, and translations +@cindex leader character, and translations +@cindex character, leader, and translations +@cindex newline character, and translations +@cindex character, newline, and translations +@cindex tab character, and translations +@cindex character, tab, and translations +@cindex @code{\a}, and translations +@cindex @code{\t}, and translations The following characters can't be translated: space (with one exception, see below), backspace, newline, leader (and @code{\a}), tab (and @code{\t}). @item -@rqindex shc +@cindex @code{shc} request, and translations Translations are not considered for finding the soft hyphen character set with the @code{shc} request. @item -@esindex \& -The character pair @samp{@var{c}\&} (this is an arbitrary character@w{ +@cindex @code{\&}, and translations +The pair @samp{@var{c}\&} (this is an arbitrary character@w{ }@var{c} followed by the zero width space character) maps this character to nothing. @@ -5127,8 +6934,8 @@ foo bar @noindent As shown in the example, the space character can't be the first -character pair as an argument of @code{tr}. Additionally, it is not -possible to map the space character to any other character; requests +character/glyph pair as an argument of @code{tr}. Additionally, it is +not possible to map the space character to any other glyph; requests like @w{@samp{.tr aa x}} undo @w{@samp{.tr aa \&}} instead. If justification is active, lines are justified in spite of the @@ -5136,21 +6943,55 @@ If justification is active, lines are justified in spite of the space character, between words). @item -After an output character has been constructed (this happens at the -moment immediately before the character is appended to an output -character list, either by direct output, in a macro, diversion, or +After an output glyph has been constructed (this happens at the +moment immediately before the glyph is appended to an output +glyph list, either by direct output, in a macro, diversion, or string), it is no longer affected by @code{tr}. -@c XXX xref +@item +Translating character to glyphs where one of them or both are +undefined is possible also; @code{tr} does not check whether the +entities in its argument do exist. + +@xref{Gtroff Internals}. + +@item +@code{troff} no longer has a hard-coded dependency on @w{Latin-1}; +all @code{char@var{XXX}} entities have been removed from the font +description files. This has a notable consequence which shows up in +warnings like @code{can't find character with input code @var{XXX}} +if the @code{tr} request isn't handled properly. + +Consider the following translation: + +@Example +.tr @'e@'E +@endExample + +@noindent +This maps input character @code{@'e} onto glyph @code{@'E}, which is +identical to glyph @code{char201}. But this glyph intentionally +doesn't exist! Instead, @code{\[char201]} is treated as an input +character entity and is by default mapped onto @code{\['E]}, and +@code{gtroff} doesn't handle translations of translations. + +The right way to write the above translation is + +@Example +.tr @'e\['E] +@endExample + +@noindent +With other words, the first argument of @code{tr} should be an input +character or entity, and the second one a glyph entity. @item Without an argument, the @code{tr} request is ignored. @end itemize @endDefreq -@esindex \! -@cindex @code{\!}, and @code{trnt} @Defreq {trnt, @Var{a}@Var{b}@Var{c}@Var{d}@dots{}} +@cindex @code{\!}, and @code{trnt} @code{trnt} is the same as the @code{tr} request except that the translations do not apply to text that is transparently throughput into a diversion with @code{\!}. @xref{Diversions}, for more @@ -5182,41 +7023,41 @@ instead of @code{tr} it prints @samp{a}. @cindex mode, nroff Originally, @code{nroff} and @code{troff} were two separate programs, -the former for tty output, the latter for everything else. With GNU +the former for TTY output, the latter for everything else. With GNU @code{troff}, both programs are merged into one executable, sending -its output to a device driver (@code{grotty} for tty devices, +its output to a device driver (@code{grotty} for TTY devices, @code{grops} for @sc{PostScript}, etc.) which interprets the intermediate output of @code{gtroff}. For @acronym{UNIX} @code{troff} it makes sense to talk about @dfn{Nroff mode} and @dfn{Troff mode} since the differences are hardcoded. For GNU @code{troff}, this distinction is not appropriate because @code{gtroff} simply takes the information given in the font files for a particular device without -handling requests specially if a tty output device is used. +handling requests specially if a TTY output device is used. Usually, a macro package can be used with all output devices. Nevertheless, it is sometimes necessary to make a distinction between -tty and non-tty devices: @code{gtroff} provides two built-in +TTY and non-TTY devices: @code{gtroff} provides two built-in conditions @samp{n} and @samp{t} for the @code{if}, @code{ie}, and @code{while} requests to decide whether @code{gtroff} shall behave like @code{nroff} or like @code{troff}. +@Defreq {troff, } @pindex troffrc @pindex troffrc-end -@Defreq {troff, } Make the @samp{t} built-in condition true (and the @samp{n} built-in condition false) for @code{if}, @code{ie}, and @code{while} conditional requests. This is the default if @code{gtroff} (@emph{not} @code{groff}) is started with the @option{-R} switch to avoid loading of the start-up files @file{troffrc} and @file{troffrc-end}. Without @option{-R}, @code{gtroff} stays in troff -mode if the output device is not a tty (e.g.@: `ps'). +mode if the output device is not a TTY (e.g.@: `ps'). @endDefreq -@pindex tty.tmac @Defreq {nroff, } +@pindex tty.tmac Make the @samp{n} built-in condition true (and the @samp{t} built-in condition false) for @code{if}, @code{ie}, and @code{while} -conditional requests. This is the default if @code{gtroff} uses a tty +conditional requests. This is the default if @code{gtroff} uses a TTY output device; the code for switching to nroff mode is in the file @file{tty.tmac} which is loaded by the start-up file @code{troffrc}. @endDefreq @@ -5224,26 +7065,10 @@ output device; the code for switching to nroff mode is in the file @xref{Conditionals and Loops}, for more details on built-in conditions. -@c XXX move the following to grotty section - -@pindex less -@cindex Teletype -@cindex ISO 6249 SGR -@cindex terminal control sequences -@cindex control sequences, for terminals -For tty output devices, underlining is done by emitting sequences of -@samp{_} and @samp{\b} (the backspace character) before the actual -character. Literally, this is printing an underline character, then -moving back one character position, and printing the actual character -at the same position as the underline character (similar to a -typewriter). Usually, a modern terminal can't interpret this (and the -original Teletype machines for which this sequence was appropriate are -no longer in use). You need a pager program like @code{less} which -translates this into ISO 6429 SGR sequences to control terminals. @c ===================================================================== -@node Line Layout, Page Layout, Troff and Nroff Mode, gtroff Reference +@node Line Layout, Line Control, Troff and Nroff Mode, gtroff Reference @section Line Layout @cindex line layout @cindex layout, line @@ -5269,50 +7094,67 @@ These dimensions are: @ftable @code @item po -@cindex left margin -@cindex margin, left -@cindex page offset -@cindex offset, page +@cindex left margin (@code{po}) +@cindex margin, left (@code{po}) +@cindex page offset (@code{po}) +@cindex offset, page (@code{po}) @dfn{Page offset} -- this is the leftmost position of text on the final output, defining the @dfn{left margin}. @item in -@cindex indentation -@cindex line indentation +@cindex indentation (@code{in}) +@cindex line indentation (@code{in}) @dfn{Indentation} -- this is the distance from the left margin where text is printed. @item ll -@cindex line length -@cindex length of line +@cindex line length (@code{ll}) +@cindex length of line (@code{ll}) @dfn{Line length} -- this is the distance from the left margin to right margin. @end ftable -@c XXX improve example +A simple demonstration: @Example +.ll 3i +This is text without indentation. +The line length has been set to 3\~inch. .in +.5i .ll -.5i -A bunch of really boring text which should -be indented from both margins. -Replace me with a better (and more) example! -.in -.5i -.ll +.5i +Now the left and right margins are both increased. +.in +.ll +Calling .in and .ll without parameters restore +the previous values. @endExample +Result: + +@Example +This is text without indenta- +tion. The line length has +been set to 3 inch. + Now the left and + right margins are + both increased. +Calling .in and .ll without +parameters restore the previ- +ous values. +@endExample + +@DefreqList {po, [@Var{offset}]} +@DefreqItem {po, @t{+}@Var{offset}} +@DefreqItem {po, @t{-}@Var{offset}} +@DefregListEnd {.o} @pindex troffrc -@Defreq {po, [@Var{offset}]} -@Defreqx {po, @t{+}@Var{offset}} -@Defreqx {po, @t{-}@Var{offset}} -@Defregx {.o} Set horizontal page offset to @var{offset} (or increment or decrement the current value by @var{offset}). Note that this request does not cause a break, so changing the page offset in the middle of text being filled may not yield the expected result. The initial value is -1@dmn{i}. For tty output devices, it is set to 0 in the startup file -@file{troffrc}; the default scaling indicator is@w{ }@code{m} (and -not@w{ }@code{v} as incorrectly documented in the original +1@dmn{i}. For TTY output devices, it is set to 0 in the startup file +@file{troffrc}; the default scaling indicator is @samp{m} (and +not @samp{v} as incorrectly documented in the original @acronym{UNIX} troff manual). The current page offset can be found in the read-only number register @@ -5334,19 +7176,20 @@ the previous value before the last call to @code{po}. @endExample @endDefreq -@Defreq {in, [@Var{indent}]} -@Defreqx {in, @t{+}@Var{indent}} -@Defreqx {in, @t{-}@Var{indent}} -@Defregx {.i} +@DefreqList {in, [@Var{indent}]} +@DefreqItem {in, @t{+}@Var{indent}} +@DefreqItem {in, @t{-}@Var{indent}} +@DefregListEnd {.i} Set indentation to @var{indent} (or increment or decrement the current value by @var{indent}). This request causes a break. Initially, there is no indentation. If @code{in} is called without an argument, the indentation is reset to the previous value before the last call to @code{in}. The default -scaling indicator is@w{ }@code{m}. +scaling indicator is @samp{m}. -The indentation is associated with the current environment. +The indentation is associated with the current environment +(@pxref{Environments}). If a negative indentation value is specified (which is not allowed), @code{gtroff} emits a warning of type @samp{range} and sets the @@ -5359,17 +7202,17 @@ The current indentation (as set by @code{in}) can be found in the read-only number register @samp{.i}. @endDefreq -@Defreq {ti, offset} -@Defreqx {ti, @t{+}@Var{offset}} -@Defreqx {ti, @t{-}@Var{offset}} -@Defregx {.in} +@DefreqList {ti, offset} +@DefreqItem {ti, @t{+}@Var{offset}} +@DefreqItem {ti, @t{-}@Var{offset}} +@DefregListEnd {.in} Temporarily indent the next output line by @var{offset}. If an increment or decrement value is specified, adjust the temporary indentation relative to the value set by the @code{in} request. This request causes a break; its value is associated with the current -environment. The default scaling indicator is@w{ }@code{m}. A call -of @code{ti} without an argument is ignored. +environment (@pxref{Environments}). The default scaling indicator +is @samp{m}. A call of @code{ti} without an argument is ignored. If the total indentation value is negative (which is not allowed), @code{gtroff} emits a warning of type @samp{range} and sets the @@ -5388,25 +7231,26 @@ into account whether a partially collected line still uses the old indentation value or a temporary indentation value is active. @endDefreq -@Defreq {ll, [@Var{length}]} -@Defreqx {ll, @t{+}@Var{length}} -@Defreqx {ll, @t{-}@Var{length}} -@Defregx {.l} -@Defregx {.ll} +@DefreqList {ll, [@Var{length}]} +@DefreqItem {ll, @t{+}@Var{length}} +@DefreqItem {ll, @t{-}@Var{length}} +@DefregItem {.l} +@DefregListEnd {.ll} Set the line length to @var{length} (or increment or decrement the current value by @var{length}). Initially, the line length is set to 6.5@dmn{i}. The effect of @code{ll} is delayed until a partially collected line (if it exists) is output. The default scaling -indicator is@w{ }@code{m}. +indicator is @samp{m}. If @code{ll} is called without an argument, the line length is reset to the previous value before the last call to @code{ll}. If a negative line length is specified (which is not allowed), @code{gtroff} emits a warning of type @samp{range} and sets the line length to zero. -The line length is associated with the current environment. +The line length is associated with the current environment +(@pxref{Environments}). -@cindex current line length register +@cindex line length register (@code{.l}) The current line length (as set by @code{ll}) can be found in the read-only number register @samp{.l}. The read-only number register @code{.ll} is the line length that applies to the current output line. @@ -5419,7 +7263,128 @@ collected line still uses the old line length value. @c ===================================================================== -@node Page Layout, Page Control, Line Layout, gtroff Reference +@node Line Control, Page Layout, Line Layout, gtroff Reference +@section Line Control +@cindex line control +@cindex control, line + +It is important to understand how @code{gtroff} handles input and output +lines. + +Many escapes use positioning relative to the input line. For example, +this + +@Example +This is a \h'|1.2i'test. + +This is a +\h'|1.2i'test. +@endExample + +@noindent +produces + +@Example +This is a test. + +This is a test. +@endExample + +The main usage of this feature is to define macros which act exactly +at the place where called. + +@Example +.\" A simple macro to underline a word +.de underline +. nop \\$1\l'|0\[ul]' +.. +@endExample + +@noindent +In the above example, @samp{|0} specifies a negative distance from the +current position (at the end of the just emitted argument @code{\$1}) back +to the beginning of the input line. Thus, the @samp{\l} escape draws a +line from right to left. + +@cindex input line continuation (@code{\}) +@cindex line, input, continuation (@code{\}) +@cindex continuation, input line (@code{\}) +@cindex output line, continuation (@code{\c}) +@cindex line, output, continuation (@code{\c}) +@cindex continuation, output line (@code{\c}) +@cindex interrupted line +@cindex line, interrupted +@code{gtroff} makes a difference between input and output line +continuation; the latter is also called @dfn{interrupting} a line. + +@DefescList {\\@key{RET}, , ,} +@DefescItem {\\c, , ,} +@DefregListEnd{.int} +Continue a line. @code{\@key{RET}} (this is a backslash at the end +of a line immediately followed by a newline) works on the input level, +suppressing the effects of the following newline in the input. + +@Example +This is a \ +.test + @result{} This is a .test +@endExample + +The @samp{|} operator is also affected. + +@cindex @code{\R}, after @code{\c} +@code{\c} works on the output level. Anything after this escape on the +same line is ignored, except @code{\R} which works as usual. Anything +before @code{\c} on the same line will be appended to the current partial +output line. The next non-command line after an interrupted line counts +as a new input line. + +The visual results depend on whether no-fill mode is active. + +@itemize @bullet +@item +@cindex @code{\c}, and no-fill mode +@cindex no-fill mode, and @code{\c} +@cindex mode, no-fill, and @code{\c} +If no-fill mode is active (using the @code{nf} request), the next input +text line after @code{\c} will be handled as a continuation of the same +input text line. + +@Example +.nf +This is a \c +test. + @result{} This is a test. +@endExample + +@item +@cindex @code{\c}, and fill mode +@cindex fill mode, and @code{\c} +@cindex mode, fill, and @code{\c} +If fill mode is active (using the @code{fi} request), a word interrupted +with @code{\c} will be continued with the text on the next input text line, +without an intervening space. + +@Example +This is a te\c +st. + @result{} This is a test. +@endExample +@end itemize + +Note that an intervening control line which causes a break is stronger +than @code{\c}, flushing out the current partial line in the usual way. + +@cindex interrupted line register (@code{.int}) +The @code{.int} register contains a positive value +if the last output line was interrupted with @code{\c}; this is +associated with the current environment (@pxref{Environments}). + +@endDefesc + +@c ===================================================================== + +@node Page Layout, Page Control, Line Control, gtroff Reference @section Page Layout @cindex page layout @cindex layout, page @@ -5427,17 +7392,17 @@ collected line still uses the old line length value. @code{gtroff} provides some very primitive operations for controlling page layout. -@cindex page length -@cindex length of page -@Defreq {pl, [@Var{length}]} -@Defreqx {pl, @t{+}@Var{length}} -@Defreqx {pl, @t{-}@Var{length}} -@Defregx {.p} +@DefreqList {pl, [@Var{length}]} +@DefreqItem {pl, @t{+}@Var{length}} +@DefreqItem {pl, @t{-}@Var{length}} +@DefregListEnd {.p} +@cindex page length (@code{pl}) +@cindex length of page (@code{pl}) Set the @dfn{page length} to @var{length} (or increment or decrement the current value by @var{length}). This is the length of the -physical output page. The default scaling indicator is@w{ }@code{v}. +physical output page. The default scaling indicator is @samp{v}. -@cindex current page length register +@cindex page length register (@code{.p}) The current setting can be found in the read-only number register @samp{.p}. @@ -5463,10 +7428,10 @@ length to 11@dmn{i}. @code{gtroff} provides several operations which help in setting up top and bottom titles (or headers and footers). -@cindex title line -@cindex three-part title -@cindex page number character @Defreq {tl, @t{'}@Var{left}@t{'}@Var{center}@t{'}@Var{right}@t{'}} +@cindex title line (@code{tl}) +@cindex three-part title (@code{tl}) +@cindex page number character (@code{%}) Print a @dfn{title line}. It consists of three parts: a left justified portion, a centered portion, and a right justified portion. The argument separator @samp{'} can be replaced with any character not @@ -5493,28 +7458,24 @@ title line with the left justified word @samp{foo}; the centered and right justfied parts are empty. @item -Any modifications to the current environment within @code{tl} (e.g.@: -changing the font or font size) are undone after processing @code{tl}. - -@item @code{tl} accepts the same parameter delimiting characters as the @code{\A} escape; see @ref{Escapes}. @end itemize @endDefreq -@cindex length of title line -@cindex title line, length -@cindex current title line length register -@Defreq {lt, [@Var{length}]} -@Defreqx {lt, @t{+}@Var{length}} -@Defreqx {lt, @t{-}@Var{length}} -@Defregx {.lt} +@DefreqList {lt, [@Var{length}]} +@DefreqItem {lt, @t{+}@Var{length}} +@DefreqItem {lt, @t{-}@Var{length}} +@DefregListEnd {.lt} +@cindex length of title line (@code{lt}) +@cindex title line, length (@code{lt}) +@cindex title line length register (@code{.lt}) The title line is printed using its own line length, which is specified (or incremented or decremented) with the @code{lt} request. Initially, the title line length is set to 6.5@dmn{i}. If a negative line length is specified (which is not allowed), @code{gtroff} emits a warning of type @samp{range} and sets the title line length to zero. -The default scaling indicator is@w{ }@code{m}. If @code{lt} is called +The default scaling indicator is @samp{m}. If @code{lt} is called without an argument, the title length is reset to the previous value before the last call to @code{lt}. @@ -5524,12 +7485,12 @@ number register; it is associated with the current environment @endDefreq -@cindex page number -@cindex number, page -@Defreq {pn, page} -@Defreqx {pn, @t{+}@Var{page}} -@Defreqx {pn, @t{-}@Var{page}} -@Defregx {.pn} +@DefreqList {pn, page} +@DefreqItem {pn, @t{+}@Var{page}} +@DefreqItem {pn, @t{-}@Var{page}} +@DefregListEnd {.pn} +@cindex page number (@code{pn}) +@cindex number, page (@code{pn}) Change (increase or decrease) the page number of the @emph{next} page. The only argument is the page number; the request is ignored without a parameter. @@ -5539,18 +7500,18 @@ page: either the value set by a @code{pn} request, or the number of the current page plus@w{ }1. @endDefreq -@cindex current page number register @Defreg {%} +@cindex page number register (@code{%}) A read-write register holding the current page number. @endDefreg -@cindex changing the page number character -@cindex page number character, changing -@vindex % @Defreq {pc, [@Var{char}]} +@cindex changing the page number character (@code{pc}) +@cindex page number character, changing (@code{pc}) +@vindex % Change the page number character (used by the @code{tl} request) to a different character. With no argument, this mechanism is disabled. -Note that this doesn't affect the number register @code{%}. +Note that this doesn't affect the number register@w{ }@code{%}. @endDefreq @xref{Traps}. @@ -5563,11 +7524,11 @@ Note that this doesn't affect the number register @code{%}. @cindex page control @cindex control, page -@rqindex pn -@cindex new page -@Defreq {bp, [@Var{page}]} -@Defreqx {bp, @t{+}@Var{page}} -@Defreqx {bp, @t{-}@Var{page}} +@DefreqList {bp, [@Var{page}]} +@DefreqItem {bp, @t{+}@Var{page}} +@DefreqListEnd {bp, @t{-}@Var{page}} +@cindex new page (@code{bp}) +@cindex page, new (@code{bp}) Stop processing the current page and move to the next page. This request causes a break. It can also take an argument to set (increase, decrease) the page number of the next page. The only @@ -5583,22 +7544,25 @@ cause a break or actually eject a page. .. \" end macro @endExample -@cindex top-level diversion -@cindex diversion, top-level +@cindex @code{bp} request, and top-level diversion +@cindex top-level diversion, and @code{bp} +@cindex diversion, top-level, and @code{bp} @code{bp} has no effect if not called within the top-level diversion (@pxref{Diversions}). @endDefreq -@cindex orphan line @Defreq {ne, [@Var{space}]} +@cindex orphan lines, preventing with @code{ne} +@cindex conditional page break (@code{ne}) +@cindex page break, conditional (@code{ne}) It is often necessary to force a certain amount of space before a new page occurs. This is most useful to make sure that there is not a single @dfn{orphan} line left at the bottom of a page. The @code{ne} request ensures that there is a certain distance, specified by the first argument, before the next page is triggered (see @ref{Traps}, -for further information). The default unit for @code{ne} is @samp{v}; -the default value of @var{space} is@w{ }1@dmn{v} if no argument is -given. +for further information). The default scaling indicator for @code{ne} +is @samp{v}; the default value of @var{space} is@w{ }1@dmn{v} if no +argument is given. For example, to make sure that no fewer than 2@w{ }lines get orphaned, do the following before each paragraph: @@ -5607,20 +7571,76 @@ do the following before each paragraph: .ne 2 text text text @endExample + +@code{ne} will then automatically cause a page break if there is space +for one line only. @endDefreq -@rqindex os -@rqindex ne -@Defreq {sv, [@Var{space}]} +@DefreqList {sv, [@Var{space}]} +@DefreqListEnd {os, } +@cindex @code{ne} request, comparison with @code{sv} @code{sv} is similar to the @code{ne} request; it reserves the specified amount of vertical space. If the desired amount of space -exists before the next trap (bottom page boundary), the space is -output immediately (ignoring a partial filled line which stays -untouched). If there is not enough space, it is stored for later -output via the @code{os} request. The default value is@w{ }1@dmn{v} -if no argument is given; the default unit is @samp{v}. +exists before the next trap (or the bottom page boundary if no trap is +set), the space is output immediately (ignoring a partially filled line +which stays untouched). If there is not enough space, it is stored for +later output via the @code{os} request. The default value is@w{ }1@dmn{v} +if no argument is given; the default scaling indicator is @samp{v}. + +@cindex @code{sv} request, and no-space mode +@cindex @code{os} request, and no-space mode +Both @code{sv} and @code{os} ignore no-space mode. While the @code{sv} +request allows negative values for @var{space}, @code{os} will ignore +them. @endDefreq +@Defreg {nl} +This register contains the current vertical position. If the vertical +position is zero and the top of page transition hasn't happened yet, +@code{nl} is set to negative value. @code{gtroff} itself does this at +the very beginning of a document before anything has been printed, but +the main usage is to plant a header trap on a page if this page has +already started. + +Consider the following: + +@Example +.de xxx +. sp +. tl ''Header'' +. sp +.. +. +First page. +.bp +.wh 0 xxx +.nr nl (-1) +Second page. +@endExample + +@noindent +Result: + +@Example +First page. + +... + + Header + +Second page. + +... +@endExample + +@noindent +Without resetting @code{nl} to a negative value, the just planted trap +would be active beginning with the @emph{next} page, not the current +one. + +@xref{Diversions}, for a comparison with the @code{.h} and @code{.d} +registers. +@endDefreg @c ===================================================================== @@ -5631,7 +7651,7 @@ if no argument is given; the default unit is @samp{v}. @code{gtroff} can switch fonts at any point in the text. The basic set of fonts is @samp{R}, @samp{I}, @samp{B}, and @samp{BI}. -These are Times Roman, Italic, Bold, and Bold Italic. For non-tty +These are Times Roman, Italic, Bold, and Bold Italic. For non-TTY devices, there is also at least one symbol font which contains various special symbols (Greek, mathematics). @@ -5649,32 +7669,34 @@ special symbols (Greek, mathematics). @node Changing Fonts, Font Families, Fonts, Fonts @subsection Changing Fonts -@cindex changing fonts -@cindex fonts, changing +@cindex fonts -@rqindex sty -@rqindex fam +@DefreqList {ft, [@Var{font}]} +@DefescItem {\\f, , f, } +@DefescItem {\\f, @lparen{}, fn, } +@DefescListEnd {\\f, @lbrack{}, font, @rbrack} +@cindex changing fonts (@code{ft}, @code{\f}) +@cindex fonts, changing (@code{ft}, @code{\f}) +@cindex @code{sty} request, and changing fonts +@cindex @code{fam} request, and changing fonts +@cindex @code{\F}, and changing fonts @kindex styles @kindex family @pindex DESC -@Defreq {ft, [@Var{font}]} -@Defescx {\\f, , f, } -@Defescx {\\f, @lparen{}, fn, } -@Defescx {\\f, @lbrack{}, font, @rbrack} The @code{ft} request and the @code{\f} escape change the current font -to @var{font} (one-character name @var{f}, two-character name +to @var{font} (one-character name@w{ }@var{f}, two-character name @var{fn}). If @var{font} is a style name (as set with the @code{sty} request or with the @code{styles} command in the @file{DESC} file), use it within -the current font family (as set with the @code{fam} request or with -the @code{family} command in the @file{DESC} file). +the current font family (as set with the @code{fam} request, @code{\F} +escape, or with the @code{family} command in the @file{DESC} file). -@cindex previous font -@cindex font, previous +@cindex previous font (@code{ft}, @code{\f[]}, @code{\fP}) +@cindex font, previous (@code{ft}, @code{\f[]}, @code{\fP}) With no argument or using @samp{P} as an argument, @code{.ft} switches -to the previous font. Use @code{\fP} or @code{\f[P]} to do this with -the escape. +to the previous font. Use @code{\f[]} to do this with the escape. The +old syntax forms @code{\fP} or @code{\f[P]} are also supported. Fonts are generally specified as upper-case strings, which are usually 1@w{ }to 4 characters representing an abbreviation or acronym of the @@ -5692,25 +7714,34 @@ and sausage. eggs, bacon, \fBspam\fP and sausage. @endExample +Note that @code{\f} doesn't produce an input token in @code{gtroff}. +As a consequence, it can be used in requests like @code{mc} (which +expects a single character as an argument) to change the font on +the fly: + +@Example +.mc \f[I]x\f[] +@endExample + @xref{Font Positions}, for an alternative syntax. @endDefreq -@rqindex ft -@rqindex ul -@rqindex bd -@esindex \f -@rqindex cs -@rqindex tkf -@rqindex special -@rqindex fspecial -@rqindex fp -@rqindex code @Defreq {ftr, f [@Var{g}]} -Translate font@w{ }@var{f} to font@w{ }@var{g}. Whenever a font named -@var{f} is referred to in a @code{\f} escape sequence, or in the +@cindex @code{ft} request, and font translations +@cindex @code{ul} request, and font translations +@cindex @code{bd} request, and font translations +@cindex @code{\f}, and font translations +@cindex @code{cs} request, and font translations +@cindex @code{tkf} request, and font translations +@cindex @code{special} request, and font translations +@cindex @code{fspecial} request, and font translations +@cindex @code{fp} request, and font translations +@cindex @code{sty} request, and font translations +Translate font@w{ }@var{f} to font@w{ }@var{g}. Whenever a font named@w{ +}@var{f} is referred to in a @code{\f} escape sequence, or in the @code{ft}, @code{ul}, @code{bd}, @code{cs}, @code{tkf}, -@code{special}, @code{fspecial}, @code{fp}, or @code{code} requests, -font@w{ }@var{g} is used. If @var{g} is missing or equal to @var{f} +@code{special}, @code{fspecial}, @code{fp}, or @code{sty} requests, +font@w{ }@var{g} is used. If @var{g} is missing or equal to@w{ }@var{f} the translation is undone. @endDefreq @@ -5729,21 +7760,34 @@ specified as the concatenation of the font family and style. Specifying a font without the family part causes @code{gtroff} to use that style of the current family. -@cindex postscript fonts -@cindex fonts, postscript -Currently, only @sc{PostScript} fonts are set up to this mechanism. +@cindex PostScript fonts +@cindex fonts, PostScript +Currently, fonts for the devices @option{-Tps}, @option{-Tdvi}, and +@option{-Tlbp} are set up to this mechanism. By default, @code{gtroff} uses the Times family with the four styles @samp{R}, @samp{I}, @samp{B}, and @samp{BI}. This way, it is possible to use the basic four fonts and to select a different font family on the command line (@pxref{Groff Options}). -@Defreq {fam, [@Var{family}]} -@Defregx {.fam} -Switch font family to @var{family}. If no argument is given, switch -back to the previous font family. The current font family is available -in the read-only number register @samp{.fam} (this is a string-valued -register); it is associated with the current environment. +@DefreqList {fam, [@Var{family}]} +@DefregItem {.fam} +@DefescItem {\\F, , f, } +@DefescItem {\\F, @lparen{}, fm, } +@DefescItem {\\F, @lbrack{}, family, @rbrack} +@DefregListEnd {.fn} +@cindex changing font family (@code{fam}, @code{\F}) +@cindex font family, changing (@code{fam}, @code{\F}) +Switch font family to @var{family} (one-character name@w{ }@var{f}, +two-character name @var{fm}). If no argument is given, switch +back to the previous font family. Use @code{\F[]} to do this with the +escape. Note that @code{\FP} doesn't work; it selects font family +@samp{P} instead. + +The value at start-up is @samp{T}. +The current font family is available in the read-only number register +@samp{.fam} (this is a string-valued register); it is associated with +the current environment. @Example spam, @@ -5758,29 +7802,46 @@ baked beans, .ft R \" family T + style R = font TR and spam. @endExample + +Note that @code{\F} doesn't produce an input token in @code{gtroff}. +As a consequence, it can be used in requests like @code{mc} (which +expects a single character as an argument) to change the font family on +the fly: + +@Example +.mc \F[P]x\F[] +@endExample + +The @samp{.fn} register contains the current @dfn{real font name} +of the current font. +This is a string-valued register. +If the current font is a style, the value of @code{\n[.fn]} +is the proper concatenation of family and style name. @endDefreq -@rqindex cs -@rqindex bd -@rqindex tkf -@rqindex uf -@rqindex fspecial @Defreq {sty, n style} +@cindex changing font style (@code{sty}) +@cindex font style, changing (@code{sty}) +@cindex @code{cs} request, and font styles +@cindex @code{bd} request, and font styles +@cindex @code{tkf} request, and font styles +@cindex @code{uf} request, and font styles +@cindex @code{fspecial} request, and font styles Associate @var{style} with font position@w{ }@var{n}. A font position can be associated either with a font or with a style. The current font is the index of a font position and so is also either a font or a -style. When it is a style, the font that is actually used is the font -the name of which is the concatenation of the name of the current +style. If it is a style, the font that is actually used is the font +which name is the concatenation of the name of the current family and the name of the current style. For example, if the current -font is@w{ }1 and font position@w{ }1 is associated with style@w{ -}@samp{R} and the current font family is@w{ }@samp{T}, then font +font is@w{ }1 and font position@w{ }1 is associated with style +@samp{R} and the current font family is @samp{T}, then font @samp{TR} will be used. If the current font is not a style, then the -current family is ignored. When the requests @code{cs}, @code{bd}, -@code{tkf}, @code{uf}, or @code{fspecial} are applied to a style, then +current family is ignored. If the requests @code{cs}, @code{bd}, +@code{tkf}, @code{uf}, or @code{fspecial} are applied to a style, they will instead be applied to the member of the current family corresponding to that style. -@var{n} must be a non-negative integer value. +@var{n}@w{ }must be a non-negative integer value. @pindex DESC @kindex styles @@ -5804,8 +7865,8 @@ is equivalent to .sty 4 BI @endExample -@code{.fam} always checks whether the current font position is valid; -this can give surprising results if the current font position is +@code{fam} and @code{\F} always check whether the current font position +is valid; this can give surprising results if the current font position is associated with a style. In the following example, we want to access the @sc{PostScript} font @@ -5846,16 +7907,18 @@ For the sake of old phototypesetters and compatibility with old versions of @code{troff}, @code{gtroff} has the concept of font @dfn{positions}, on which various fonts are mounted. -@Defreq {fp, pos font [@Var{external-name}]} -@Defregx {.f} -@Defregx {.fp} +@DefreqList {fp, pos font [@Var{external-name}]} +@DefregItem {.f} +@DefregListEnd {.fp} +@cindex mounting font (@code{fp}) +@cindex font, mounting (@code{fp}) Mount font @var{font} at position @var{pos} (which must be a non-negative integer). This numeric position can then be referred to with font changing commands. When @code{gtroff} starts it is using font position@w{ }1 (which must exist; position@w{ }0 is unused usually at start-up). -@cindex current font position register +@cindex font position register (@code{.f}) The current font in use, as a font position, is available in the read-only number register @samp{.f}. This can be useful to remember the current font for later recall. It is associated with the current @@ -5868,7 +7931,7 @@ environment (@pxref{Environments}). .ft \n[save-font] @endExample -@cindex next free font position register +@cindex next free font position register (@code{.fp}) The number of the next free font position is available in the read-only number register @samp{.fp}. This is useful when mounting a new font, like so: @@ -5899,23 +7962,27 @@ fonts with long names in compatibility mode. Both the @code{ft} request and the @code{\f} escape have alternative syntax forms to access font positions. -@rqindex sty -@rqindex fam +@DefreqList {ft, nnn} +@DefescItem {\\f, , n, } +@DefescItem {\\f, @lparen{}, nn, } +@DefescListEnd {\\f, @lbrack{}, nnn, @rbrack} +@cindex changing font position (@code{\f}) +@cindex font position, changing (@code{\f}) +@cindex @code{sty} request, and font positions +@cindex @code{fam} request, and font positions +@cindex @code{\F}, and font positions @kindex styles @kindex family @pindex DESC -@Defreq {ft, nnn} -@Defescx {\\f, , n, } -@Defescx {\\f, @lparen{}, nn, } -@Defescx {\\f, @lbrack{}, nnn, @rbrack} -Change the current font position to @var{nnn} (one-digit position -@var{n}, two-digit position @var{nn}), which must be a non-negative +Change the current font position to @var{nnn} (one-digit position@w{ +}@var{n}, two-digit position @var{nn}), which must be a non-negative integer. If @var{nnn} is associated with a style (as set with the @code{sty} request or with the @code{styles} command in the @file{DESC} file), use -it within the current font family (as set with the @code{fam} request or -with the @code{family} command in the @file{DESC} file). +it within the current font family (as set with the @code{fam} request, +the @code{\F} escape, or with the @code{family} command in the @file{DESC} +file). @Example this is font 1 @@ -5950,17 +8017,10 @@ written in a roman or an italic font, yielding two different glyphs); sometimes more than one character maps to a single glyph (this is a @dfn{ligature} -- the most common is `fi'). -@c XXX - -Please note that currently the distinction between glyphs and -characters in this reference is not clearly carried out. This will be -improved eventually in the next revision. - @cindex symbol @cindex special fonts @kindex fonts @pindex DESC -@rqindex fspecial A @dfn{symbol} is simply a named glyph. Within @code{gtroff}, all glyph names of a particular font are defined in its font file. If the user requests a glyph not available in this font, @code{gtroff} looks @@ -5973,42 +8033,100 @@ special fonts. Fonts mounted with the @code{fonts} keyword in the special fonts locally (i.e.@: for a particular font), use the @code{fspecial} request. +In summary, @code{gtroff} tries the following to find a given symbol: + +@itemize @bullet +@item +If the symbol has been defined with the @code{char} request, use it. +This hides a symbol with the same name in the current font. + +@item +Check the current font. + +@item +If the symbol has been defined with the @code{fchar} request, use it. + +@item +Check all fonts given with the @code{fspecial} request, in the order +of appearance in @code{fspecial} calls. + +@item +Check all fonts given with the @code{special} request, in the order +of appearance in @code{special} calls (inclusively the special fonts +defined in the @file{DESC} file, which come first). + +@item +As a last resort, consult all fonts loaded up to now (in the order they +have been called the first time) for special fonts and check them. +@end itemize + @xref{Font Files}, and @ref{Special Fonts}, for more details. -@Defesc {\\, @lparen{}, nm, } -@Defescx {\\, @lbrack{}, name, @rbrack} +@DefescList {\\, @lparen{}, nm, } +@DefescListEnd {\\, @lbrack{}, name, @rbrack} Insert a symbol @var{name} (two-character name @var{nm}). There is no special syntax for one-character names -- the natural form -@samp{\@var{n}} would collide with escapes. +@samp{\@var{n}} would collide with escapes.@footnote{Note that a +one-character symbol is not the same as an input character, i.e., the +character @code{a} is not the same as @code{\[a]}. By default, +@code{groff} defines only a single one-character symbol, @code{\[-]}; +it is usually accessed as @code{\-}. On the other hand, @code{gtroff} +has the special feature that @code{\[char@var{XXX}]} is the same as the +input character with character code @var{XXX}. For example, +@code{\[char97]} is identical to the letter @code{a} if @acronym{ASCII} +encoding is active.} If @var{name} is undefined, a warning of type @samp{char} is generated, and the escape is ignored. @xref{Debugging}, for information about warnings. -The list of available symbols is device dependent; see @ref{Glyph Name -Index} for some of them discussed in this reference. +@cindex list of available glyphs (@cite{groff_char(7)} man page) +@cindex available glyphs, list (@cite{groff_char(7)} man page) +@cindex glyphs, available, list (@cite{groff_char(7)} man page) +The list of available symbols is device dependent; see the +@cite{groff_char(7)} man page for a complete list for the given output +device. For example, say + +@Example +man -Tdvi groff_char > groff_char.dvi +@endExample + +@noindent +for a list using the default DVI fonts (not all versions of the +@code{man} program support the @option{-T} option). If you want to +use an additional macro package to change the used fonts, @code{groff} +must be called directly: + +@Example +groff -Tdvi -mec -man groff_char.7 > groff_char.dvi +@endExample @c XXX list of common symbols @endDefesc @Defesc {\\C, ', xxx, '} -Typeset the character named @var{xxx}. Normally it is more convenient -to use @code{\[@var{xxx}]}, but @code{\C} has the advantage that it is -compatible with newer versions of @code{ditroff} and is available in -compatibility mode. +@cindex named character (@code{\C}) +@cindex character, named (@code{\C}) +Typeset the glyph named @var{xxx}.@footnote{@code{\C} is actually a +misnomer since it accesses an output glyph.} Normally it is more +convenient to use @code{\[@var{xxx}]}, but @code{\C} has the advantage +that it is compatible with newer versions of @acronym{AT&T} +@code{troff} and is available in compatibility mode. @endDefesc -@rqindex char -@cindex unicode @Defesc {\\N, ', n, '} -Typeset the character with code@w{ }@var{n} in the current font (this -is @strong{not} the input character code). @var{n} can be any -integer. Most devices only have characters with codes between 0 -and@w{ }255; the Unicode output device uses codes in the range -0--65535. If the current font does not contain a character with that -code, special fonts are @emph{not} searched. The @code{\N} escape -sequence can be conveniently used in conjunction with the @code{char} -request: +@cindex numbered glyph (@code{\N}) +@cindex glyph, numbered (@code{\N}) +@cindex @code{char} request, used with @code{\N} +@cindex Unicode +Typeset the glyph with code@w{ }@var{n} in the current font +(@code{n}@w{ }is @strong{not} the input character code). The +number @var{n}@w{ }can be any non-negative decimal integer. Most devices +only have glyphs with codes between 0 and@w{ }255; the Unicode +output device uses codes in the range 0--65535. If the current +font does not contain a glyph with that code, special fonts are +@emph{not} searched. The @code{\N} escape sequence can be +conveniently used in conjunction with the @code{char} request: @Example .char \[phone] \f[ZD]\N'37' @@ -6016,117 +8134,171 @@ request: @noindent @pindex DESC -@cindex unnamed characters -@cindex characters, unnamed -The code of each character is given in the fourth column in the font +@cindex unnamed glyphs +@cindex glyphs, unnamed +The code of each glyph is given in the fourth column in the font description file after the @code{charset} command. It is possible to -include unnamed characters in the font description file by using a +include unnamed glyphs in the font description file by using a name of @samp{---}; the @code{\N} escape sequence is the only way to use these. @endDefesc -@c XXX should be `glyph', not `character' +Some escape sequences directly map onto special glyphs. + +@Defesc {\\', , , } +This is a backslash followed by the apostrophe character, @acronym{ASCII} +character @code{0x27} (@acronym{EBCDIC} character @code{0x7D}). The same +as @code{\[aa]}, the acute accent. +@endDefesc + +@Defesc {\\`, , , } +This is a backslash followed by @acronym{ASCII} character @code{0x60} +(@acronym{EBCDIC} character @code{0x79} usually). The same as +@code{\[ga]}, the grave accent. +@endDefesc + +@Defesc {\\-, , , } +This is the same as @code{\[-]}, the minus sign in the current font. +@endDefesc -@cindex character properties -@cindex properties of characters @Defreq {cflags, n c1 c2 @dots{}} -Each character has certain properties associated with it. These -properties can be modified with the @code{cflags} request. The first -argument is the the sum of the desired flags and the remaining -arguments are the characters to have those properties. It is possible -to omit the spaces between the characters. +@cindex glyph properties (@code{cflags}) +@cindex character properties (@code{cflags}) +@cindex properties of glyphs (@code{cflags}) +@cindex properties of characters (@code{cflags}) +Input characters and symbols have certain properties associated +with it.@footnote{Note that the output glyphs themselves don't have +such properties. For @code{gtroff}, a glyph is a numbered box with +a given width, depth, and height, nothing else. All manipulations +with the @code{cflags} request work on the input level.} These +properties can be modified with the @code{cflags} request. The +first argument is the sum of the desired flags and the remaining +arguments are the characters or symbols to have those properties. +It is possible to omit the spaces between the characters or symbols. @table @code @item 1 -@cindex end of sentence characters -@cindex characters, end of sentence -the character ends sentences (initially characters @samp{.?!} have this -property) +@cindex end-of-sentence characters +@cindex characters, end-of-sentence +The character ends sentences (initially characters @samp{.?!} have this +property). @item 2 @cindex hyphenating characters @cindex characters, hyphenation -lines can be broken before the character (initially no characters have -this property) +Lines can be broken before the character (initially no characters have +this property). @item 4 -@glindex hy -@glindex em -lines can be broken after the character (initially the characters -@samp{-\(hy\(em} have this property) +@cindex @code{hy} glyph, and @code{cflags} +@cindex @code{em} glyph, and @code{cflags} +Lines can be broken after the character (initially the character +@samp{-} and the symbols @samp{\(hy} and @samp{\(em} have this property). @item 8 @cindex overlapping characters @cindex characters, overlapping -@glindex ul -@glindex rn -@glindex ru -the character overlaps horizontally (initially the characters -@samp{\(ul\(rn\(ru} have this property) +@cindex @code{ul} glyph, and @code{cflags} +@cindex @code{rn} glyph, and @code{cflags} +@cindex @code{ru} glyph, and @code{cflags} +The character overlaps horizontally (initially the symbols +@samp{\(ul\(rn\(ru} have this property). @item 16 -@glindex br -the character overlaps vertically (initially character @samp{\(br} has -this property) +@cindex @code{br} glyph, and @code{cflags} +The character overlaps vertically (initially symbol @samp{\(br} has +this property). @item 32 @cindex transparent characters @cindex character, transparent -@cindex ' -@cindex " -@cindex ] -@cindex ) -@cindex * -@glindex dg -@glindex rq -an end of sentence character followed by any number of characters with +@cindex @code{"}, at end of sentence +@cindex @code{'}, at end of sentence +@cindex @code{)}, at end of sentence +@cindex @code{]}, at end of sentence +@cindex @code{*}, at end of sentence +@cindex @code{dg} glyph, at end of sentence +@cindex @code{rq} glyph, at end of sentence +An end-of-sentence character followed by any number of characters with this property is treated as the end of a sentence if followed by a newline or two spaces; in other words the character is -@dfn{transparent} for the purposes of end of sentence recognition -- +@dfn{transparent} for the purposes of end-of-sentence recognition -- this is the same as having a zero space factor in @TeX{} (initially -characters @samp{"')]*\(dg\(rq} have this property). +characters @samp{"')]*} and the symbols @samp{\(dg\(rq} have this +property). @end table @endDefreq -@cindex defining characters -@cindex characters, defining -@cindex creating new characters -@cindex escape character -@cindex character, escape -@rqindex tr -@rqindex cp -@rqindex rc -@rqindex lc -@esindex \l -@esindex \L -@esindex \& -@esindex \e -@rqindex hcode -@Defreq {char, c [@Var{string}]} -Define a new character@w{ }@var{c} to be @var{string} (which can be -empty). Every time character@w{ }@var{c} needs to be printed, +@DefreqList {char, g [@Var{string}]} +@DefreqListEnd {fchar, g [@Var{string}]} +@cindex defining character (@code{char}) +@cindex character, defining (@code{char}) +@cindex creating new characters (@code{char}) +@cindex defining symbol (@code{char}) +@cindex symbol, defining (@code{char}) +@cindex defining glyph (@code{char}) +@cindex glyph, defining (@code{char}) +@cindex escape character, while defining glyph +@cindex character, escape, while defining glyph +@cindex @code{tr} request, and glyph definitions +@cindex @code{cp} request, and glyph definitions +@cindex @code{rc} request, and glyph definitions +@cindex @code{lc} request, and glyph definitions +@cindex @code{\l}, and glyph definitions +@cindex @code{\L}, and glyph definitions +@cindex @code{\&}, and glyph definitions +@cindex @code{\e}, and glyph definitions +@cindex @code{hcode} request, and glyph definitions +Define a new glyph@w{ }@var{g} to be @var{string} (which can be +empty).@footnote{@code{char} is a misnomer since an output glyph is +defined.} Every time glyph@w{ }@var{g} needs to be printed, @var{string} is processed in a temporary environment and the result is wrapped up into a single object. Compatibility mode is turned off and the escape character is set to @samp{\} while @var{string} is being processed. Any emboldening, constant spacing or track kerning is applied to this object rather than to individual characters in -@var{string}. A character defined by this request can be used just -like a normal character provided by the output device. In particular, -other characters can be translated to it with the @code{tr} request; -it can be made the leader character by the @code{lc} request; repeated -patterns can be drawn with the character using the @code{\l} and -@code{\L} escape sequences; words containing the character can be -hyphenated correctly, if the @code{hcode} request is used to give the -character a hyphenation code. There is a special anti-recursion -feature: Use of character within the character's definition is handled -like normal characters not defined with @code{char}. -@endDefreq - -@cindex removing character definition -@cindex character, removing definition +@var{string}. + +A glyph defined by this request can be used just +like a normal glyph provided by the output device. In particular, +other characters can be translated to it with the @code{tr} or +@code{trin} requests; it can be made the leader character by the +@code{lc} request; repeated patterns can be drawn with the glyph +using the @code{\l} and @code{\L} escape sequences; words containing +the glyph can be hyphenated correctly if the @code{hcode} request +is used to give the glyph's symbol a hyphenation code. + +There is a special anti-recursion feature: Use of @code{g} within +the glyph's definition is handled like normal characters and symbols +not defined with @code{char}. + +Note that the @code{tr} and @code{trin} requests take precedence if +@code{char} accesses the same symbol. + +@Example +.tr XY +X + @result{} Y +.char X Z +X + @result{} Y +.tr XX +X + @result{} Z +@endExample + +The @code{fchar} request defines a fallback glyph: +@code{gtroff} only checks for glyphs defined with @code{fchar} +if it cannot find the glyph in the current font. +@code{gtroff} carries out this test before checking special fonts. +@endDefreq + @Defreq {rchar, c1 c2 @dots{}} -Remove the definitions of characters @var{c1}, @var{c2},@w{ -}@enddots{} This undoes the effect of a @code{char} request. +@cindex removing glyph definition (@code{rchar}) +@cindex glyph, removing definition (@code{rchar}) +Remove the definitions of glyphs @var{c1}, @var{c2},@w{ +}@enddots{} This undoes the effect of a @code{char} or @code{fchar} +request. It is possible to omit the whitespace between arguments. @endDefreq @@ -6140,9 +8312,31 @@ It is possible to omit the whitespace between arguments. @cindex special fonts @cindex fonts, special -@c XXX +Special fonts are those that @code{gtroff} searches +when it cannot find the requested glyph in the current font. +The Symbol font is usually a special font. + +@code{gtroff} provides the following two requests to add more special +fonts. @xref{Using Symbols}, for a detailed description of the glyph +searching mechanism in @code{gtroff}. -To be written. +Usually, only non-TTY devices have special fonts. + +@DefreqList {special, s1 s2 @dots{}} +@DefreqListEnd {fspecial, f s1 s2 @dots{}} +@kindex fonts +@pindex DESC +Use the @code{special} request to define special fonts. They are +appended to the list of global special fonts in the given order. +The first entries in this list are the fonts defined with the +@code{fonts} command in the @file{DESC} file which are marked as +special in the corresponding font description files. + +Use the @code{fspecial} request to designate special fonts +only when font@w{ }@var{f} font is active. They are appended to the +list of special fonts for @var{f} in the given order. Initially, this +list is empty. +@endDefreq @c --------------------------------------------------------------------- @@ -6151,15 +8345,73 @@ To be written. @cindex artificial fonts @cindex fonts, artificial -There are a number of requests for artificially creating fonts. These -are largely vestiges of the days when output devices did not have a -wide variety of fonts, and when @code{nroff} and @code{troff} were -separate programs. These are no longer necessary in GNU -@code{troff}. Nevertheless, they are supported. +There are a number of requests and escapes for artificially creating +fonts. These are largely vestiges of the days when output devices +did not have a wide variety of fonts, and when @code{nroff} and +@code{troff} were separate programs. Most of them are no longer +necessary in GNU @code{troff}. Nevertheless, they are supported. + +@DefescList {\\H, ', height, '} +@DefescItem {\\H, ', @t{+}@Var{height}, '} +@DefescListEnd {\\H, ', @t{-}@Var{height}, '} +@cindex changing the font height (@code{\H}) +@cindex font height, changing (@code{\H}) +@cindex height, font, changing (@code{\H}) +Change (increment, decrement) the height of the current font, but not +the width. If @var{height} is zero, restore the original height. +Default scaling indicator is @samp{z}. + +Currently, only the @option{-Tps} device supports this feature. + +Note that @code{\H} doesn't produce an input token in @code{gtroff}. +As a consequence, it can be used in requests like @code{mc} (which +expects a single character as an argument) to change the font on +the fly: + +@Example +.mc \H'+5z'x\H'0' +@endExample + +In compatibility mode, @code{gtroff} behaves differently: If an +increment or decrement is used, it is always taken relative to the +current point size and not relative to the previously selected font +height. Thus, + +@Example +.cp 1 +\H'+5'test \H'+5'test +@endExample + +@noindent +prints the word @samp{test} twice with the same font height (five +points larger than the current font size). +@endDefesc + +@DefescList {\\S, ', slant, '} +@cindex changing the font slant (@code{\S}) +@cindex font slant, changing (@code{\S}) +@cindex slant, font, changing (@code{\S}) +Slant the current font by @var{slant} degrees. Positive values slant +to the right. + +Currently, only the @option{-Tps} device supports this feature. + +Note that @code{\S} doesn't produce an input token in @code{gtroff}. +As a consequence, it can be used in requests like @code{mc} (which +expects a single character as an argument) to change the font on +the fly: + +@Example +.mc \S'20'x\S'0' +@endExample + +This request is incorrectly documented in the original @acronym{UNIX} +troff manual; the slant is always set to an absolute value. +@endDefesc -@cindex underlining @Defreq {ul, [@Var{lines}]} -The @code{ul} request normally underlines subsequent lines if a tty +@cindex underlining (@code{ul}) +The @code{ul} request normally underlines subsequent lines if a TTY output device is used. Otherwise, the lines are printed in italics (only the term `underlined' is used in the following). The single argument is the number of input lines to be underlined; with no @@ -6174,43 +8426,39 @@ underline font is activated. Within the span of a @code{ul} request, it is possible to change fonts, but after the last line affected by @code{ul} the saved font is restored. -@cindex underline font -@cindex font, for underlining -@rqindex uf -This command is associated with the current environment. The -underline font can be changed with the @code{uf} request. +This number of lines still to be underlined is associated with the +current environment (@pxref{Environments}). The underline font can be +changed with the @code{uf} request. @c XXX @xref should be changed to grotty -@xref{Troff and Nroff Mode}, for a discussion how underlining is -implemented in for tty output devices, and which problems can arise. +@c @xref{Troff and Nroff Mode}, for a discussion how underlining is +@c implemented in for TTY output devices, and which problems can arise. The @code{ul} request does not underline spaces. @endDefreq -@cindex continuous underlining -@cindex underlining, continuous @Defreq {cu, [@Var{lines}]} +@cindex continuous underlining (@code{cu}) +@cindex underlining, continuous (@code{cu}) The @code{cu} request is similar to @code{ul} but underlines spaces as -well (if a tty output device is used). +well (if a TTY output device is used). @endDefreq -@cindex underline font -@cindex font for underlining -@rqindex ul -@rqindex cu @Defreq {uf, font} +@cindex underline font (@code{uf}) +@cindex font for underlining (@code{uf}) Set the underline font (globally) used by @code{ul} and @code{cu}. By default, this is the font at position@w{ }2. @var{font} can be either a non-negative font position or the name of a font. @endDefreq -@cindex imitating bold face -@cindex bold face, imitating -@Defreq {bd, font [@Var{offset}]} -@Defreqx {bd, font1 font2 [@Var{offset}]} -@Defregx {.b} -Artificially create a bold font by printing each character twice, +@DefreqList {bd, font [@Var{offset}]} +@DefreqItem {bd, font1 font2 [@Var{offset}]} +@DefregListEnd {.b} +@cindex imitating bold face (@code{bd}) +@cindex bold face, imitating (@code{bd}) +Artificially create a bold font by printing each glyph twice, slightly offset. Two syntax forms are available. @@ -6219,7 +8467,7 @@ Two syntax forms are available. @item Imitate a bold font unconditionally. The first argument specifies the font to embolden, and the second is the number of basic units, minus -one, by which the two characters is offset. If the second argument is +one, by which the two glyphs are offset. If the second argument is missing, emboldening is turned off. @var{font} can be either a non-negative font position or the name of a @@ -6229,7 +8477,7 @@ font. special font is active; in the @code{bd} request, its default unit is @samp{u}. -@rqindex fspecial +@cindex @code{fspecial} request, and imitating bold @kindex special @cindex embolding of special fonts @cindex special fonts, emboldening @@ -6245,19 +8493,20 @@ command in font files or with the @code{fspecial} request). @end itemize @endDefreq -@cindex constant character space mode -@cindex mode for constant character space -@cindex character, constant space -@rqindex ps @Defreq {cs, font [@Var{width} [@Var{em-size}]]} -Switch to and from constant character space mode. If activated, the -width of every character is @math{@var{width}/36} ems. The em size is +@cindex constant glyph space mode (@code{cs}) +@cindex mode for constant glyph space (@code{cs}) +@cindex glyph, constant space +@cindex @code{ps} request, and constant glyph space mode +Switch to and from @dfn{constant glyph space mode}. If activated, the +width of every glyph is @math{@var{width}/36} ems. The em size is given absolutely by @var{em-size}; if this argument is missing, the em value is taken from the current font size (as set with the @code{ps} request) when the font is effectively in use. Without second and -third argument, constant character space mode is deactivated. +third argument, constant glyph space mode is deactivated. -Default unit for @var{em-size} is @samp{z}; @var{width} is an integer. +Default scaling indicator for @var{em-size} is @samp{z}; @var{width} is +an integer. @endDefreq @c --------------------------------------------------------------------- @@ -6267,26 +8516,27 @@ Default unit for @var{em-size} is @samp{z}; @var{width} is an integer. @cindex ligatures and kerning @cindex kerning and ligatures -Ligatures are groups of characters that are run together. For -example, the letters `f' and `i' can form a ligature `fi' as in the -word `file'. This produces a cleaner look (albeit subtle) to the -printed output. Usually, ligatures are not available in fonts for tty -output devices. +Ligatures are groups of characters that are run together, i.e, producing +a single glyph. For example, the letters `f' and `i' can form a +ligature `fi' as in the word `file'. This produces a cleaner look +(albeit subtle) to the printed output. Usually, ligatures are not +available in fonts for TTY output devices. Most @sc{PostScript} fonts support the fi and fl ligatures. The C/A/T -typesetter that was the target of AT&T @code{troff} also supported -`ff', `ffi', and `ffl' ligatures. Advanced typesetters or `expert' -fonts may include ligatures for `ft' and `ct', although GNU +typesetter that was the target of @acronym{AT&T} @code{troff} also +supported `ff', `ffi', and `ffl' ligatures. Advanced typesetters or +`expert' fonts may include ligatures for `ft' and `ct', although GNU @code{troff} does not support these (yet). -@cindex ligatures enabled register -@Defreq {lg, [@Var{flag}]} -@Defregx {.lg} -The ligature mechanism can be switched on or off with the @code{lg} -request; if the parameter is non-zero or missing, ligatures are -enabled, otherwise disabled. Default is on. The current ligature -mode can be found in the read-only number register @code{.lg} (set to -1 or@w{ }2 if ligatures are enabled, 0@w{ }otherwise). +@DefreqList {lg, [@Var{flag}]} +@DefregListEnd {.lg} +@cindex activating ligatures (@code{lg}) +@cindex ligatures, activating (@code{lg}) +@cindex ligatures enabled register (@code{.lg}) +Switch the ligature mechanism on or off; if the parameter is non-zero +or missing, ligatures are enabled, otherwise disabled. Default is on. +The current ligature mode can be found in the read-only number register +@code{.lg} (set to 1 or@w{ }2 if ligatures are enabled, 0@w{ }otherwise). Setting the ligature mode to@w{ }2 enables the two-character ligatures (fi, fl, and ff) and disables the three-character ligatures (ffi and @@ -6294,28 +8544,30 @@ ffl). @endDefreq @dfn{Pairwise kerning} is another subtle typesetting mechanism that -modifies the distance between a character pair to improve readability. +modifies the distance between a glyph pair to improve readability. In most cases (but not always) the distance is decreased. @ifnotinfo For example, compare the combination of the letters `V' and `A'. With kerning, `VA' is printed. Without kerning it appears as `V@w{}A'. @end ifnotinfo -Typewriter-like fonts and fonts for terminals where all characters +Typewriter-like fonts and fonts for terminals where all glyphs have the same width don't use kerning. -@cindex kerning enabled register -@Defreq {kern, [@Var{flag}]} -@Defregx {.kern} -Kerning can be activated with the @code{kern} request. If the -parameter is non-zero or missing, enable pairwise kerning, otherwise -disable it. The read-only number register @code{.kern} is set to@w{ -}1 if pairwise kerning is enabled, 0@w{ }otherwise. - -@cindex zero width space character -@cindex character, zero width space -@cindex space character, zero width +@DefreqList {kern, [@Var{flag}]} +@DefregListEnd {.kern} +@cindex activating kerning (@code{kern}) +@cindex kerning, activating (@code{kern}) +@cindex kerning enabled register (@code{.kern}) +Switch kerning on or off. If the parameter is non-zero or missing, +enable pairwise kerning, otherwise disable it. The read-only number +register @code{.kern} is set to@w{ }1 if pairwise kerning is enabled, +0@w{ }otherwise. + +@cindex zero width space character (@code{\&}) +@cindex character, zero width space (@code{\&}) +@cindex space character, zero width (@code{\&}) If the font description file contains pairwise kerning information, -characters from that font are kerned. Kerning between two characters +glyphs from that font are kerned. Kerning between two glyphs can be inhibited by placing @code{\&} between them: @samp{V\&A}. @xref{Font File Format}. @@ -6323,15 +8575,17 @@ can be inhibited by placing @code{\&} between them: @samp{V\&A}. @cindex track kerning @cindex kerning, track -@dfn{Track kerning} expands or reduces the space between characters. +@dfn{Track kerning} expands or reduces the space between glyphs. This can be handy, for example, if you need to squeeze a long word onto a single line or spread some text to fill a narrow column. It must be used with great care since it is usually considered bad typography if the reader notices the effect. @Defreq {tkf, f s1 n1 s2 n2} +@cindex activating track kerning (@code{tkf}) +@cindex track kerning, activating (@code{tkf}) Enable track kerning for font@w{ }@var{f}. If the current font is@w{ -}@var{f} the width of every character is increased by an amount +}@var{f} the width of every glyph is increased by an amount between @var{n1} and @var{n2} (@var{n1}, @var{n2} can be negative); if the current point size is less than or equal to @var{s1} the width is increased by @var{n1}; if it is greater than or equal to @var{s2} the @@ -6339,28 +8593,33 @@ width is increased by @var{n2}; if the point size is greater than or equal to @var{s1} and less than or equal to @var{s2} the increase in width is a linear function of the point size. -The default unit is @samp{z} for @var{s1} and @var{s2}, @samp{p} for -@var{n1} and @var{n2}. +The default scaling indicator is @samp{z} for @var{s1} and @var{s2}, +@samp{p} for @var{n1} and @var{n2}. + +Note that the track kerning amount is added even to the rightmost glyph +in a line; for large values it is thus recommended to increase the line +length by the same amount to compensate it. @endDefreq Sometimes, when typesetting letters of different fonts, more or less space at such boundaries are needed. There are two escapes to help with this. -@cindex italic correction -@cindex correction, italic -@cindex correction between italic and roman character -@cindex roman character, correction after italic character -@cindex italic character, correction before roman character @Defesc {\\/, , , } -Increase the width of the preceding character so that the spacing -between that character and the following character is correct if the -following character is a roman character. For example, if an +@cindex italic correction (@code{\/}) +@cindex correction, italic (@code{\/}) +@cindex correction between italic and roman glyph (@code{\/}, @code{\,}) +@cindex roman glyph, correction after italic glyph (@code{\/}) +@cindex italic glyph, correction before roman glyph (@code{\/}) +@cindex glyph, italic correction (@code{\/}) +Increase the width of the preceding glyph so that the spacing +between that glyph and the following glyph is correct if the +following glyph is a roman glyph. For example, if an italic@w{ }@code{f} is immediately followed by a roman right -parenthesis, then in many fonts the top right portion of the @code{f} +parenthesis, then in many fonts the top right portion of the@w{ }@code{f} overlaps the top left of the right parenthesis. Use this escape -sequence whenever an italic character is immediately followed by a -roman character without any intervening space. This small amount of +sequence whenever an italic glyph is immediately followed by a +roman glyph without any intervening space. This small amount of space is also called @dfn{italic correction}. @iftex @@ -6375,16 +8634,17 @@ space is also called @dfn{italic correction}. @end iftex @endDefesc -@cindex left italic correction -@cindex correction, left italic -@cindex roman character, correction before italic character -@cindex italic character, correction after roman character @Defesc {\\\,, , , } -Modify the spacing of the following character so that the spacing -between that character and the preceding character is correct if the -preceding character is a roman character. Use this escape sequence -whenever a roman character is immediately followed by an italic -character without any intervening space. In analogy to above, this +@cindex left italic correction (@code{\,}) +@cindex correction, left italic (@code{\,}) +@cindex glyph, left italic correction (@code{\,}) +@cindex roman glyph, correction before italic glyph (@code{\,}) +@cindex italic glyph, correction after roman glyph (@code{\,}) +Modify the spacing of the following glyph so that the spacing +between that glyph and the preceding glyph is correct if the +preceding glyph is a roman glyph. Use this escape sequence +whenever a roman glyph is immediately followed by an italic +glyph without any intervening space. In analogy to above, this space could be called @dfn{left italic correction}, but this term isn't used widely. @@ -6406,7 +8666,7 @@ is to stop interaction of a character with its surrounding. @itemize @bullet @item -It prevents the insertion of extra space after an end of sentence +It prevents the insertion of extra space after an end-of-sentence character. @Example @@ -6430,7 +8690,7 @@ an input line. @endExample @item -It prevents kerning between two characters. +It prevents kerning between two glyphs. @ifnotinfo @example @@ -6449,6 +8709,32 @@ request (@pxref{Character Translations}). @end itemize @endDefesc +@Defesc {\\), , , } +This escape is similar to @code{\&} except that it behaves like a +character declared with the @code{cflags} request to be transparent +for the purposes of an end-of-sentence character. + +Its main usage is in macro definitions to protect against arguments +starting with a control character. + +@Example +.de xxx +\)\\$1 +.. +.de yyy +\&\\$1 +.. +This is a test.\c +.xxx ' +This is a test. + @result{}This is a test.' This is a test. +This is a test.\c +.yyy ' +This is a test. + @result{}This is a test.' This is a test. +@endExample +@endDefesc + @c ===================================================================== @@ -6463,7 +8749,7 @@ request (@pxref{Character Translations}). @cindex spacing, vertical @code{gtroff} uses two dimensions with each line of text, type size and vertical spacing. The @dfn{type size} is approximately the height -of the tallest character.@footnote{This is usually the parenthesis. +of the tallest glyph.@footnote{This is usually the parenthesis. Note that in most cases the real dimensions of the glyphs in a font are @emph{not} related to its type size! For example, the standard @sc{PostScript} font families `Times Roman', `Helvetica', and @@ -6479,7 +8765,7 @@ term papers). By default, @code{gtroff} uses 10@w{ }point type on @cindex leading The difference between type size and vertical spacing is known, by -typesetters, as @dfn{leading}. +typesetters, as @dfn{leading} (this is pronounced `ledding'). @menu * Changing Type Sizes:: @@ -6490,22 +8776,25 @@ typesetters, as @dfn{leading}. @node Changing Type Sizes, Fractional Type Sizes, Sizes, Sizes @subsection Changing Type Sizes -@cindex changing type sizes -@cindex type sizes, changing - -@Defreq {ps, [@Var{size}]} -@Defreqx {ps, @t{+}@Var{size}} -@Defreqx {ps, @t{-}@Var{size}} -@Defescx {\\s, , size, } -@Defregx {.s} + +@DefreqList {ps, [@Var{size}]} +@DefreqItem {ps, @t{+}@Var{size}} +@DefreqItem {ps, @t{-}@Var{size}} +@DefescItem {\\s, , size, } +@DefregListEnd {.s} +@cindex changing type sizes (@code{ps}, @code{\s}) +@cindex type sizes, changing (@code{ps}, @code{\s}) +@cindex point sizes, changing (@code{ps}, @code{\s}) Use the @code{ps} request or the @code{\s} escape to change (increase, decrease) the type size (in points). Specify @var{size} as either an absolute point size, or as a relative change from the current size. The size@w{ }0, or no argument, goes back to the previous size. -Default unit of @code{size} is @samp{z}. If @code{size} is zero or -negative, it is set to 1@dmn{u}. +Default scaling indicator of @code{size} is @samp{z}. If @code{size} +is zero or negative, it is set to 1@dmn{u}. +@cindex type size registers (@code{.s}, @code{.ps}) +@cindex point size registers (@code{.s}, @code{.ps}) The read-only number register @code{.s} returns the point size in points as a decimal fraction. This is a string. To get the point size in scaled points, use the @code{.ps} register instead. @@ -6548,26 +8837,52 @@ Increase or decrease the point size by @var{nn}@w{ }points. @var{nn} must be exactly two digits. @end table +Note that @code{\s} doesn't produce an input token in @code{gtroff}. +As a consequence, it can be used in requests like @code{mc} (which +expects a single character as an argument) to change the font on +the fly: + +@Example +.mc \s[20]x\s[0] +@endExample + @xref{Fractional Type Sizes}, for yet another syntactical form of using the @code{\s} escape. +@endDefreq +@Defreq {sizes, s1 s2 @dots{} sn [0]} Some devices may only have certain permissible sizes, in which case @code{gtroff} rounds to the nearest permissible size. +The @file{DESC} file specifies which sizes are permissible for the device. + +Use the @code{sizes} request to change the permissible sizes +for the current output device. +Arguments are in scaled points; +the @code{sizescale} line in the +@file{DESC} file for the output device +provides the scaling factor. +For example, if the scaling factor is 1000, +then the value 12000 is 12@w{ }points. + +Each argument can be a single point size (such as @samp{12000}), +or a range of sizes (such as @samp{4000-72000}). +You can optionally end the list with a zero. @endDefreq -@cindex current type size register -@cindex current vertical spacing register -@Defreq {vs, [@Var{space}]} -@Defreqx {vs, @t{+}@Var{space}} -@Defreqx {vs, @t{-}@Var{space}} -@Defregx {.v} +@DefreqList {vs, [@Var{space}]} +@DefreqItem {vs, @t{+}@Var{space}} +@DefreqItem {vs, @t{-}@Var{space}} +@DefregListEnd {.v} +@cindex changing vertical line spacing (@code{vs}) +@cindex vertical line spacing, changing (@code{vs}) +@cindex vertical line spacing register (@code{.v}) Change (increase, decrease) the vertical spacing by @var{space}. The -default unit is @samp{p}. +default scaling indicator is @samp{p}. If @code{vs} is called without an argument, the vertical spacing is reset to the previous value before the last call to @code{vs}. -@vindex .V +@cindex @code{.V} register, and @code{vs} @code{gtroff} creates a warning of type @samp{range} if @var{space} is zero or negative; the vertical spacing is then set to the vertical resolution (as given in the @code{.V} register). @@ -6577,30 +8892,85 @@ spacing; it is associated with the current environment (@pxref{Environments}). @endDefreq -@c XXX example +@cindex vertical line spacing, effective value +The effective vertical line spacing consists of four components. + +@itemize @bullet +@item +The vertical line spacing as set with the @code{vs} request. + +@cindex post-vertical line spacing +@cindex line spacing, post-vertical (@code{pvs}) +@item +The @dfn{post-vertical line spacing} as set with the @code{pvs} request. +This is vertical space which will be added after a line has been +output. + +@cindex extra pre-vertical line space (@code{\x}) +@cindex line space, extra pre-vertical (@code{\x}) +@item +The @dfn{extra pre-vertical line space} as set with the @code{\x} request, +using a negative value. This is vertical space which will be added once +before the current line has been output. + +@cindex extra post-vertical line space (@code{\x}) +@cindex line space, extra post-vertical (@code{\x}) +@item +The @dfn{extra post-vertical line space} as set with the @code{\x} request, +using a positive value. This is vertical space which will be added once +after the current line has been output. +@end itemize + +@cindex double-spacing (@code{vs}, @code{pvs}) +It is usually better to use @code{vs} or @code{pvs} instead of @code{ls} +to produce double-spaced documents: @code{vs} and @code{pvs} have a finer +granularity for the inserted vertical space compared to @code{ls}; +furthermore, certain preprocessors assume single-spacing. + +@xref{Manipulating Spacing}, for more details on the @code{\x} escape +and the @code{ls} request. + +@DefreqList {pvs, [@Var{space}]} +@DefreqItem {pvs, @t{+}@Var{space}} +@DefreqItem {pvs, @t{-}@Var{space}} +@DefregListEnd {.pvs} +@cindex @code{ls} request, alternative to (@code{pvs}) +@cindex post-vertical line spacing, changing (@code{pvs}) +@cindex post-vertical line spacing register (@code{.pvs}) +Change (increase, decrease) the post-vertical spacing by +@var{space}. The default scaling indicator is @samp{p}. + +If @code{pvs} is called without an argument, the post-vertical spacing is +reset to the previous value before the last call to @code{pvs}. + +@code{gtroff} creates a warning of type @samp{range} if @var{space} is +zero or negative; the vertical spacing is then set to zero. + +The read-only number register @code{.pvs} contains the current +post-vertical spacing; it is associated with the current environment +(@pxref{Environments}). +@endDefreq -@ignore -@Example -... .sz macro example?? ... -@endExample -@end ignore @c --------------------------------------------------------------------- @node Fractional Type Sizes, , Changing Type Sizes, Sizes @subsection Fractional Type Sizes @cindex fractional type sizes +@cindex fractional point sizes @cindex type sizes, fractional +@cindex point sizes, fractional +@cindex sizes, fractional @cindex @code{s} unit @cindex unit, @code{s} @cindex @code{z} unit @cindex unit, @code{z} -@rqindex ps -@rqindex cs -@rqindex tkf -@esindex \H -@esindex \s +@cindex @code{ps} request, with fractional type sizes +@cindex @code{cs} request, with fractional type sizes +@cindex @code{tkf} request, with fractional type sizes +@cindex @code{\H}, with fractional type sizes +@cindex @code{\s}, with fractional type sizes A @dfn{scaled point} is equal to @math{1/@var{sizescale}} points, where @var{sizescale} is specified in the @file{DESC} file (1@w{ }by default). There is a new scale indicator @samp{z} which has the @@ -6632,7 +9002,6 @@ number of units in a scaled point. So, for example, @samp{\n[.ps]s} is equal to @samp{1m}. Be sure not to confuse the @samp{s} and @samp{z} scale indicators. -@vindex .s @Defreg {.ps} A read-only number register returning the point size in scaled points. @@ -6640,12 +9009,12 @@ A read-only number register returning the point size in scaled points. (@pxref{Environments}). @endDefreg -@cindex last-requested point size register -@cindex point size, last-requested -@vindex .ps -@vindex .s -@Defreg {.psr} -@Defregx {.sr} +@DefregList {.psr} +@DefregListEnd {.sr} +@cindex last-requested point size registers (@code{.psr}, @code{.sr}) +@cindex point size registers, last-requested (@code{.psr}, @code{.sr}) +@cindex @code{.ps} register, in comparison with @code{.psr} +@cindex @code{.s} register, in comparison with @code{.sr} The last-requested point size in scaled points is contained in the @code{.psr} read-only number register. The last requested point size in points as a decimal fraction can be found in @code{.sr}. This is a @@ -6653,9 +9022,9 @@ string-valued read-only number register. Note that the requested point sizes are device-independent, whereas the values returned by the @code{.ps} and @code{.s} registers are not. -For example, if a point size of 11@dmn{pt} is requested for a DVI -device, 10.95@dmn{pt} are actually used (as specified in the -@file{DESC} file). +For example, if a point size of 11@dmn{pt} is requested, and a +@code{sizes} request (or a @code{sizescale} line in a @file{DESC} file) +specifies 10.95@dmn{pt} instead, this value is actually used. Both registers are associated with the current environment (@pxref{Environments}). @@ -6667,7 +9036,7 @@ fractional type sizes: @table @code @item \s[@var{n}] @itemx \s'@var{n}' -Set the point size to @var{n} scaled points; @var{n}@w{ }is a numeric +Set the point size to @var{n}@w{ }scaled points; @var{n}@w{ }is a numeric expression with a default scale indicator of @samp{z}. @item \s[+@var{n}] @@ -6678,8 +9047,8 @@ expression with a default scale indicator of @samp{z}. @itemx \s'-@var{n}' @itemx \s+'@var{n}' @itemx \s-'@var{n}' -Increase or or decrease the point size by @var{n} scaled points; -@var{n} is a numeric expression with a default scale indicator of +Increase or or decrease the point size by @var{n}@w{ }scaled points; +@var{n}@w{ }is a numeric expression with a default scale indicator of @samp{z}. @end table @@ -6696,38 +9065,46 @@ Increase or or decrease the point size by @var{n} scaled points; convenience (i.e.@: there are no built-in strings exept @code{.T}, but even this is a read-write string variable). -@cindex string interpolation -@cindex string expansion -@cindex interpolation of strings -@cindex expansion of strings -@Defreq {ds, name [@Var{string}]} -@Defescx {\\*, , n, } -@Defescx {\\*, @lparen{}, nm, } -@Defescx {\\*, @lbrack{}, name, @rbrack{}} -Define and access a string variable @var{name} (one-character name -@var{n}, two-character name @var{nm}). If @var{name} already exists, -@code{ds} overwrites the previous definition. +@DefreqList {ds, name [@Var{string}]} +@DefreqItem {ds1, name [@Var{string}]} +@DefescItem {\\*, , n, } +@DefescItem {\\*, @lparen{}, nm, } +@DefescListEnd {\\*, @lbrack{}, name arg1 arg2 @dots{}, @rbrack{}} +@cindex string interpolation (@code{\*}) +@cindex string expansion (@code{\*}) +@cindex interpolation of strings (@code{\*}) +@cindex expansion of strings (@code{\*}) +@cindex string arguments +@cindex arguments, of strings +Define and access a string variable @var{name} (one-character name@w{ +}@var{n}, two-character name @var{nm}). If @var{name} already exists, +@code{ds} overwrites the previous definition. Only the syntax form +using brackets can take arguments which are handled identically to +macro arguments; the single exception is that a closing bracket as an +argument must be enclosed in double quotes. @xref{Request Arguments}, +and @ref{Parameters}. Example: @Example -.ds UX \s-1UNIX\s0\u\s-3tm\s0\d +.ds foo a \\$1 test . -The \*(UX Operating System +This is \*[foo nice]. + @result{} This is a nice test. @endExample The @code{\*} escape @dfn{interpolates} (expands in-place) a previously-defined string variable. To be more precise, the stored string is pushed onto the input stack which is then parsed by @code{gtroff}. Similar to number registers, it is possible to nest -strings, i.e. a string variables can be called within string -variables. +strings, i.e. string variables can be called within string variables. -If the string named by the @code{\*} does not exist, it is defined as -empty, and a warning of type @samp{mac} is emitted (see +If the string named by the @code{\*} escape does not exist, it is +defined as empty, and a warning of type @samp{mac} is emitted (see @ref{Debugging}, for more details). @cindex comments, with @code{ds} +@cindex @code{ds} request, and comments @strong{Caution:} Unlike other requests, the second argument to the @code{ds} request takes up the entire line including trailing spaces. This means that comments on a line with such a request can introduce @@ -6749,6 +9126,7 @@ escape adjacent with the end of the string. @cindex quotes, trailing @cindex leading spaces with @code{ds} @cindex spaces with @code{ds} +@cindex @code{ds} request, and leading spaces To produce leading space the string can be started with a double quote. No trailing quote is needed; in fact, any trailing quote is included in your string. @@ -6757,11 +9135,10 @@ included in your string. .ds sign " Yours in a white wine sauce, @endExample -@esindex \@key{RET} @cindex multi-line strings @cindex strings, multi-line -@cindex newline character in strings, escaping -@cindex escaping newline characters in strings +@cindex newline character, in strings, escaping +@cindex escaping newline characters, in strings Strings are not limited to a single line of text. A string can span several lines by escaping the newlines with a backslash. The resulting string is stored @emph{without} the newlines. @@ -6772,11 +9149,34 @@ of text are on these \ next several lines @endExample -It is not possible to have real newlines in a string. +It is not possible to have real newlines in a string. To put a single +double quote character into a string, use two consecutive double quote +characters. -@cindex name space of macros and strings -@cindex macros, shared name space with strings -@cindex strings, shared name space with macros +The @code{ds1} request turns off compatibility mode +while interpreting a string. To be more precise, a @dfn{compatibility +save} input token is inserted at the beginning of the string, and a +@dfn{compatibility restore} input token at the end. + +@Example +.nr xxx 12345 +.ds aa The value of xxx is \\n[xxx]. +.ds1 bb The value of xxx ix \\n[xxx]. +. +.cp 1 +. +\*(aa + @result{} warning: number register `[' not defined + @result{} The value of xxx is 0xxx]. +\*(bb + @result{} The value of xxx ix 12345. +@endExample + +@cindex name space, common, of macros, diversions, and strings +@cindex common name space of macros, diversions, and strings +@cindex macros, shared name space with strings and diversions +@cindex strings, shared name space with macros and diversions +@cindex diversions, shared name space with macros and strings Strings, macros, and diversions (and boxes) share the same name space. Internally, even the same mechanism is used to store them. This has some interesting consequences. For example, it is possible to call a @@ -6795,8 +9195,7 @@ This is @result{} This is a funny test. @endExample -Diversions and boxes can be also called with string syntax. It is not -possible to pass arguments to a macro if called with @code{\*}. +Diversions and boxes can be also called with string syntax. Another consequence is that you can copy one-line diversions or boxes to a string. @@ -6838,8 +9237,13 @@ final newline from a diversion. Another disadvantage is that the spaces in the copied string are already formatted, making them unstretchable. This can cause ugly results. -@rqindex chop -@rqindex unformat +@cindex stripping final newline in diversions +@cindex diversion, stripping final newline +@cindex final newline, stripping in diversions +@cindex newline, final, stripping in diversions +@cindex horizontal space, unformatting +@cindex space, horizontal, unformatting +@cindex unformatting horizontal space A clean solution to this problem is available in GNU @code{troff}, using the requests @code{chop} to remove the final newline of a diversion, and @code{unformat} to make the horizontal spaces @@ -6861,9 +9265,10 @@ This is \*[xxx]. @xref{Gtroff Internals}, for more information. @endDefreq -@cindex appending to strings -@cindex strings, appending -@Defreq {as, name [@Var{string}]} +@DefreqList {as, name [@Var{string}]} +@DefreqListEnd {as1, name [@Var{string}]} +@cindex appending to a string (@code{as}) +@cindex string, appending (@code{as}) The @code{as} request is similar to @code{ds} but appends @var{string} to the string stored as @var{name} instead of redefining it. If @var{name} doesn't exist yet, it is created. @@ -6871,60 +9276,85 @@ to the string stored as @var{name} instead of redefining it. If @Example .as sign " with shallots, onions and garlic, @endExample + +The @code{as1} request is similar to @code{as}, but compatibility mode +is switched off while the appended string is interpreted. To be more +precise, a @dfn{compatibility save} input token is inserted at the +beginning of the appended string, and a @dfn{compatibility restore} +input token at the end. @endDefreq Rudimentary string manipulation routines are given with the next two requests. -@cindex substring @Defreq {substring, str n1 [@Var{n2}]} -Replace the string in register@w{ }@var{str} with the substring +@cindex substring (@code{substring}) +Replace the string named @var{str} with the substring defined by the indices @var{n1} and@w{ }@var{n2}. The first character -in the string has index one. If @var{n2} is omitted, it is taken to +in the string has index@w{ }0. If @var{n2} is omitted, it is taken to be equal to the string's length. If the index value @var{n1} or -@var{n2} is negative or zero, it is counted from the end of the -string, going backwards: The last character has index@w{ }0, the -character before the last character has index@w{ }@minus{}1, etc. +@var{n2} is negative, it is counted from the end of the +string, going backwards: The last character has index@w{ }@minus{}1, the +character before the last character has index@w{ }@minus{}2, etc. @Example .ds xxx abcdefgh -.substring xxx 2 -3 +.substring xxx 1 -4 \*[xxx] @result{} bcde @endExample @endDefreq -@cindex length of a string -@cindex string, length of @Defreq {length, reg str} -Compute the length of @var{str} and returns it in the number -register@w{ }@var{reg}. If @var{reg} doesn't exist, it is created. +@cindex length of a string (@code{length}) +@cindex string, length of (@code{length}) +Compute the number of characters of @var{str} and return it in the +number register @var{reg}. If @var{reg} doesn't exist, it is created. +@code{str} is read in copy mode. @Example -.ds xxx abcdefgh -.length yyy xxx +.ds xxx abcd\h'3i'efgh +.length yyy \n[xxx] \n[yyy] - @result{} 8 + @result{} 14 @endExample @endDefreq -@cindex rename request -@cindex rename macro -@cindex rename string @Defreq {rn, xx yy} -Rename the request, macro, or string @var{xx} to @var{yy}. +@cindex renaming request (@code{rn}) +@cindex request, renaming (@code{rn}) +@cindex renaming macro (@code{rn}) +@cindex macro, renaming (@code{rn}) +@cindex renaming string (@code{rn}) +@cindex string, renaming (@code{rn}) +@cindex renaming diversion (@code{rn}) +@cindex diversion, renaming (@code{rn}) +Rename the request, macro, diversion, or string @var{xx} to @var{yy}. @endDefreq -@cindex remove request -@cindex remove macro -@cindex remove string @Defreq {rm, xx} -Remove the request, macro, or string @var{xx}. @code{gtroff} treats -subsequent invocations as if the object had never been defined. +@cindex removing request (@code{rm}) +@cindex request, removing (@code{rm}) +@cindex removing macro (@code{rm}) +@cindex macro, removing (@code{rm}) +@cindex removing string (@code{rm}) +@cindex string, removing (@code{rm}) +@cindex removing diversion (@code{rm}) +@cindex diversion, removing (@code{rm}) +Remove the request, macro, diversion, or string @var{xx}. @code{gtroff} +treats subsequent invocations as if the object had never been defined. @endDefreq -@cindex alias @Defreq {als, new old} +@cindex alias, string, creating (@code{als}) +@cindex alias, macro, creating (@code{als}) +@cindex alias, diversion, creating (@code{als}) +@cindex creating alias, for string (@code{als}) +@cindex creating alias, for macro (@code{als}) +@cindex creating alias, for diversion (@code{als}) +@cindex string, creating alias (@code{als}) +@cindex macro, creating alias (@code{als}) +@cindex diversion, creating alias (@code{als}) Create an alias named @var{new} for the request, string, macro, or diversion object named @var{old}. The new name and the old name are exactly equivalent (it is similar to a hard rather than a soft @@ -6934,10 +9364,10 @@ type @samp{mac} and ignores the request. @Defreq {chop, xx} Remove (chop) the last character from the macro, string, or diversion -named @var{xx}. This is useful for removing the newline from the end +named @var{xx}. This is useful for removing the newline from the end of diversions that are to be interpolated as strings. This command can be used repeatedly; see @ref{Gtroff Internals}, for details on -nodes inserted by @code{gtroff} automatically. +nodes inserted additionally by @code{gtroff}. @endDefreq @xref{Identifiers}, and @ref{Comments}. @@ -6961,10 +9391,8 @@ nodes inserted by @code{gtroff} automatically. @node Operators in Conditionals, if-else, Conditionals and Loops, Conditionals and Loops @subsection Operators in Conditionals -@rqindex if -@rqindex while -@cindex @code{if}, operators to use with it -@cindex @code{while}, operators to use with it +@cindex @code{if} request, operators to use with +@cindex @code{while} request, operators to use with In @code{if} and @code{while} requests, there are several more operators available: @@ -6974,17 +9402,16 @@ operators available: True if the current page is even or odd numbered (respectively). @item n -@rqindex nroff True if the document is being processed in nroff mode (i.e., the @code{.nroff} command has been issued). @item t -@rqindex troff True if the document is being processed in troff mode (i.e., the @code{.troff} command has been issued). @item v -Always false. +Always false. This condition is for compatibility with other +@code{troff} versions only. @item '@var{xxx}'@var{yyy}' True if the string @var{xxx} is equal to the string @var{yyy}. Other @@ -7001,11 +9428,11 @@ false @endExample @noindent -The resulting motions, character sizes, and fonts have to +The resulting motions, glyph sizes, and fonts have to match,@footnote{The created output nodes must be identical. @xref{Gtroff Internals}.} and not the individual motion, size, and font requests. In the previous example, @samp{|} and @samp{\fR|\fP} -both result in a roman @samp{|} character with the same point size and +both result in a roman @samp{|} glyph with the same point size and at the same location on the page, so the strings are equal. If @samp{.ft@w{ }I} had been added before the @samp{.ie}, the result would be ``false'' because (the first) @samp{|} produces an italic @@ -7017,12 +9444,15 @@ True if there is a number register named @var{xxx}. @item d @var{xxx} True if there is a string, macro, diversion, or request named @var{xxx}. -@item c @var{ch} -@rqindex char -True if there is a character @var{ch} available; @var{ch} is either an -@acronym{ASCII} character or a special character (@code{\(@var{ch}} or -@code{\[@var{ch}]}); the condition is also true if @var{ch} has been -defined by the @code{char} request. +@item m @var{xxx} +True if there is a color named @var{xxx}. + +@item c @var{g} +True if there is a glyph @var{g} available@footnote{The name of this +conditional operator is a misnomer since it tests names of output +glyphs.}; @var{g} is either an @acronym{ASCII} character or a special +character (@code{\(@var{gg}} or @code{\[@var{ggg}]}); the condition +is also true if @var{g} has been defined by the @code{char} request. @end table Note that these operators can't be combined with other operators like @@ -7080,26 +9510,39 @@ more info. @endExample @endDefreq -@c XXX .nop request +@Defreq{nop, anything} +Executes @var{anything}. +This is similar to @code{.if@w{ }1}. +@endDefreq -@Defreq {ie, expr anything} -@Defreqx {el, anything} +@DefreqList {ie, expr anything} +@DefreqListEnd {el, anything} Use the @code{ie} and @code{el} requests to write an if-then-else. The first request is the `if' part and the latter is the `else' part. @Example -.ie n .ls 2 \" double spacing in nroff -.el .ls 1 \" single spacing in troff +.ie n .ls 2 \" double-spacing in nroff +.el .ls 1 \" single-spacing in troff @endExample @endDefreq -@c this is a bug in makeinfo: you can't have `@{' as an argument -@c to deffn +@c there is a bug in makeinfo <= 4.1a: you can't have `@{' as an argument +@c to @deffn +@c +@c and in 4.2 you still can't use @{ in macros. +@c @DefescList {\@{, , , } +@c @DefescListEnd {\@}, , , } +@deffn Escape @t{\@{} +@deffnx Escape @t{\@}} @esindex \@{ @esindex \@} -@c @Defesc {\\@@@{, , , } -@c @Defescx {\\@@@}, , , } +@cindex begin of conditional block (@code{\@{}) +@cindex end of conditional block (@code{\@}}) +@cindex conditional block, begin (@code{\@{}) +@cindex conditional block, end (@code{\@}}) +@cindex block, conditional, begin (@code{\@{}) +@cindex block, condititional, end (@code{\@}}) In many cases, an if (or if-else) construct needs to execute more than one request. This can be done using the @code{\@{} and @code{\@}} escapes. The following example shows the possible ways to use these @@ -7116,6 +9559,7 @@ escapes (note the position of the opening and closing braces). . ds rq "\@} @endExample @c @endDefesc +@end deffn @xref{Expressions}. @@ -7144,7 +9588,7 @@ to@w{ }0. Some remarks. -@rqindex de +@cindex @code{de} request, and @code{while} @itemize @bullet @item The body of a @code{while} request is treated like the body of a @@ -7204,16 +9648,16 @@ The closing brace of a @code{while} body must end a line. @end itemize @endDefreq -@rqindex while -@cindex @code{break}, in a @code{while} loop -@cindex @code{continue}, in a @code{while} loop @Defreq {break, } +@cindex @code{while} request, confusing with @code{br} +@cindex @code{break} request, in a @code{while} loop +@cindex @code{continue} request, in a @code{while} loop Break out of a @code{while} loop. Be sure not to confuse this with the @code{br} request (causing a line break). @endDefreq @Defreq {continue, } -Finishes the current iteration of a @code{while} loop, immediately +Finish the current iteration of a @code{while} loop, immediately restarting the next iteration. @endDefreq @@ -7230,14 +9674,16 @@ restarting the next iteration. A @dfn{macro} is a collection of text and embedded commands which can be invoked multiple times. Use macros to define common operations. -@Defreq {de, name [@Var{end}]} +@DefreqList {de, name [@Var{end}]} +@DefreqItem {de1, name [@Var{end}]} +@DefreqListEnd {dei, name [@Var{end}]} Define a new macro named @var{name}. @code{gtroff} copies subsequent lines (starting with the next one) into an internal buffer until it encounters the line @samp{..} (two dots). The optional second argument to @code{de} changes this to a macro to @samp{.@var{end}}. -Note that no leading whitespace is allowed in the line containing the -ending token (either @samp{..} or the macro @samp{.@var{end}}). +There can be whitespace after the first dot in the line containing the +ending token (either @samp{.} or macro @samp{@var{end}}). Here a small example macro called @samp{P} which causes a break and inserts some vertical space. It could be used to separate paragraphs. @@ -7249,25 +9695,85 @@ inserts some vertical space. It could be used to separate paragraphs. .. @endExample -@c XXX add info about macro definitions in macros. +The following example defines a macro within another. Remember that +expansion must be protected twice; once for reading the macro and +once for executing. + +@Example +\# a dummy macro to avoid a warning +.de end +.. +. +.de foo +. de bar end +. nop \f[B]Hallo \\\\$1!\f[] +. end +.. +. +.foo +.bar Joe + @result{} @b{Hallo Joe!} +@endExample + +@noindent +Since @code{\f} has no expansion, it isn't necessary to protect its +backslash. Had we defined another macro within @code{bar} which takes +a parameter, eight backslashes would be necessary before @samp{$1}. -@c XXX give example for end macro. +The @code{de1} request turns off compatibility mode +while executing the macro. On entry, the current compatibility mode +is saved and restored at exit. -@c XXX add info about indirect macro calls: -@c -@c .de xxx -@c from yyy\c -@c .. -@c -@c test \*[xxx] test -@c => test from yyy test +@Example +.nr xxx 12345 +. +.de aa +The value of xxx is \\n[xxx]. +.. +.de1 bb +The value of xxx ix \\n[xxx]. +.. +. +.cp 1 +. +.aa + @result{} warning: number register ' not defined + @result{} The value of xxx is 0xxx]. +.bb + @result{} The value of xxx ix 12345. +@endExample -@c XXX info about common identifier pool for strings, macros, and -@c diversions. +The @code{dei} request defines a macro indirectly. +That is, it expands strings whose names +are @var{name} or @var{end} before performing the append. + +This: + +@Example +.ds xx aa +.ds yy bb +.dei xx yy +@endExample + +@noindent +is equivalent to: + +@Example +.de aa bb +@endExample + +@pindex trace.tmac +Using @file{trace.tmac}, you can trace calls to @code{de} and @code{de1}. + +Note that macro identifiers are shared with identifiers for strings and +diversions. @endDefreq -@cindex appending, to a macro -@Defreq {am, xx} +@DefreqList {am, xx} +@DefreqItem {am1, xx} +@DefreqListEnd {ami, xx yy} +@cindex appending to a macro (@code{am}) +@cindex macro, appending (@code{am}) Works similarly to @code{de} except it appends onto the macro named @var{xx}. So, to make the previously defined @samp{P} macro actually do indented instead of block paragraphs, add the necessary code to the @@ -7278,21 +9784,31 @@ existing macro like this: .ti +5n .. @endExample + +The @code{am1} request turns off compatibility mode +while executing the appended macro piece. To be more precise, a +@dfn{compatibility save} input token is inserted at the beginning of +the appended code, and a @dfn{compatibility restore} input token at +the end. + +The @code{ami} request appends indirectly, +meaning that @code{gtroff} expands strings whose names +are @var{xx} or @var{yy} before performing the append. + +@pindex trace.tmac +Using @file{trace.tmac}, you can trace calls to @code{am} and @code{am1}. @endDefreq -@cindex alias -@Defreq {als, new old} -Create an alias named @var{new} for the request, string, macro, or -diversion object named @var{old}. The new name and the old name are -exactly equivalent (it is similar to a hard rather than a soft -link). If @var{old} is undefined, @code{gtroff} generates a warning of -type @samp{mac} and ignores the request. +@xref{Strings}, for the @code{als} request to rename a macro. + +The @code{de}, @code{am}, @code{di}, @code{da}, @code{ds}, and +@code{as} requests (together with its variants) only create a new object +if the name of the macro, diversion or string diversion is currently +undefined or if it is defined to be a request; normally they modify the +value of an existing object. -The @code{de}, @code{am}, @code{di}, @code{da}, @code{ds}, -and @code{as} requests only create a new object if the name -of the macro, diversion or string diversion is currently -undefined or if it is defined to be a request; normally -they modify the value of an existing object. +@Defreq {return, } +Exit a macro, immediately returning to the caller. @endDefreq @menu @@ -7307,19 +9823,14 @@ they modify the value of an existing object. @cindex copy-in mode @cindex mode, copy-in -@esindex \n -@esindex \$ -@esindex \* -@esindex \\ -@esindex \@key{RET} @cindex @code{\n}, when reading text for a macro @cindex @code{\$}, when reading text for a macro @cindex @code{\*}, when reading text for a macro @cindex @code{\\}, when reading text for a macro @cindex \@key{RET}, when reading text for a macro -When @code{gtroff} reads in the text for a macro or diversion, it copies -the text (including request lines, but excluding escapes) into an -internal buffer. Escapes are converted into an internal form, +When @code{gtroff} reads in the text for a macro, string, or diversion, +it copies the text (including request lines, but excluding escapes) into +an internal buffer. Escapes are converted into an internal form, except for @code{\n}, @code{\$}, @code{\*}, @code{\\} and @code{\@key{RET}} which are evaluated and inserted into the text where the escape was located. This is known as @dfn{copy-in} mode or @@ -7348,62 +9859,69 @@ The following example prints the numbers 20 and@w{ }10: @subsection Parameters @cindex parameters -@vindex .$ -The arguments to a macro can be examined using a variety of escapes. -The number of arguments is available in the @code{.$} number register. +The arguments to a macro or string can be examined using a variety of +escapes. + +@Defreg {.$} +@cindex number of arguments register (@code{.$}) +The number of arguments passed to a macro or string. This is a read-only +number register. +@endDefreg + Any individual argument can be retrieved with one of the following escapes: +@DefescList {\\$, , n, } +@DefescItem {\\$, @lparen{}, nn, } +@DefescListEnd {\\$, @lbrack{}, nnn, @rbrack{}} @cindex copy-in mode, and macro arguments -@Defesc {\\$, n, , } -@Defescx {\\$, @lparen{}, nn, } -@Defescx {\\$, @lbrack{}, nnn, @rbrack{}} -The escapes @code{\$@var{n}}, @code{\$(@var{nn}} and -@code{\$[@var{nnn}]} retrieve the @var{n}@dmn{th}, @var{nn}@dmn{th} or -@var{nnn}@dmn{th} argument. As usual, the first form only accepts a -single number (larger than zero), the second a two-digit number (larger -or equal to@w{ }10), and the third any positive integer value (larger -than zero). Macros can have an unlimited number of arguments. Note -that due to copy-in mode, use two backslashes on these in actual use to -prevent interpolation until the macro is actually invoked. +@cindex macro, arguments (@code{\$}) +@cindex arguments, macro (@code{\$}) +Retrieve the @var{n}@dmn{th}, @var{nn}@dmn{th} or @var{nnn}@dmn{th} +argument. As usual, the first form only accepts a single number +(larger than zero), the second a two-digit number (larger or equal +to@w{ }10), and the third any positive integer value (larger +than zero). Macros and strings can have an unlimited number of arguments. +Note that due to copy-in mode, use two backslashes on these in actual use +to prevent interpolation until the macro is actually invoked. @endDefesc @Defreq {shift, [@Var{n}]} -Shifts the arguments 1@w{ }position, or as +Shift the arguments 1@w{ }position, or as many positions as specified by its argument. After executing this -request, argument@w{ }@var{i} becomes argument @var{i}-@var{n}; +request, argument@w{ }@var{i} becomes argument @math{@var{i}-@var{n}}; arguments 1 to@w{ }@var{n} are no longer available. Shifting by negative amounts is currently undefined. @endDefreq -@Defesc {\\$*, , , } -@Defescx {\\$@@, , , } +@DefescList {\\$*, , , } +@DefescListEnd {\\$@@, , , } In some cases it is convenient to use all of the arguments at once (for example, to pass the arguments along to another macro). The @code{\$*} escape concatenates all the arguments separated by spaces. A similar escape is @code{\$@@}, which concatenates all the arguments with each surrounded by double quotes, and separated by -spaces. +spaces. If not in compatibility mode, the input level of double quotes +is preserved (see @ref{Request Arguments}). @endDefesc -@rqindex als -@cindex @code{als}, use with @code{\$0} @Defesc {\\$0, , , } +@cindex macro name register (@code{\$0}) +@cindex @code{als} request, and @code{\$0} The name used to invoke the current macro. The @code{als} request can make a macro have more than one name. @Example -.de vl -.ie \\n(.$=1 .ds Vl Pre-Release Version -.el .ds Vl Version \\$3, \\$4. +.de generic-macro +. ... +. if \\n[error] \@{\ +. tm \\$0: Houston, we have a problem. +. return +. \@} .. -@endExample - -@noindent -This would be called as - -@Example -.vl $Id: groff.texinfo,v 1.77 2001/05/07 13:36:24 wlemb Exp $ +. +.als foo generic-macro +.als bar generic-macro @endExample @endDefesc @@ -7417,102 +9935,167 @@ This would be called as @cindex page motions @cindex motions, page -@cindex @code{sp}, as vertical page motion -@Defreq {sp, [@Var{len}]} -Motions up and down the page can be done with the @code{sp} request. -However, this causes a break so that the actual effect is to move to the -left margin and then to the specified location. -@endDefreq - -@Defreq {mk, [@Var{reg}]} -@Defreqx {rt, reg} +@xref{Manipulating Spacing}, for a discussion of the main request for +vertical motion, @code{sp}. + +@DefreqList {mk, [@Var{reg}]} +@DefreqListEnd {rt, [@Var{dist}]} +@cindex marking vertical page location (@code{mk}) +@cindex page location, vertical, marking (@code{mk}) +@cindex location, vertical, page, marking (@code{mk}) +@cindex vertical page location, marking (@code{mk}) +@cindex returning to marked vertical page location (@code{rt}) +@cindex page location, vertical, returning to marked (@code{rt}) +@cindex location, vertical, page, returning to marked (@code{rt}) +@cindex vertical page location, returning to marked (@code{rt}) The request @code{mk} can be used to mark a location on a page, for -movement to later. This request takes a register name as an argument in -which to store the current page location. With no argument it -stores the location in an internal register. The results of this can be -used later by the @code{rt} or the @code{sp} request. The @code{rt} -request returns @emph{upwards} to the location given in the register -name given as an argument; with no argument it returns to the -location marked with the @code{mk} request. - -@c XXX example -@ignore +movement to later. This request takes a register name as an argument +in which to store the current page location. With no argument it +stores the location in an internal register. The results of this can +be used later by the @code{rt} or the @code{sp} request (or the +@code{\v} escape). + +The @code{rt} request returns @emph{upwards} to the location marked +with the last @code{mk} request. If used with an argument, return to +a position which distance from the top of the page is @var{dist} (no +previous call to @code{mk} is necessary in this case). Default scaling +indicator is @samp{v}. + +Here a primitive solution for a two-column macro. + @Example -... dual column example ... +.nr column-length 1.5i +.nr column-gap 4m +.nr bottom-margin 1m +. +@endExample +@Example +.de 2c +. br +. mk +. ll \\n[column-length]u +. wh -\\n[bottom-margin]u 2c-trap +. nr right-side 0 +.. +. +@endExample +@Example +.de 2c-trap +. ie \\n[right-side] \@{\ +. nr right-side 0 +. po -(\\n[column-length]u + \\n[column-gap]u) +. \" remove trap +. wh -\\n[bottom-margin]u +. \@} +. el \@{\ +. \" switch to right side +. nr right-side 1 +. po +(\\n[column-length]u + \\n[column-gap]u) +. rt +. \@} +.. +. +@endExample +@Example +.pl 1.5i +.ll 4i +This is a small test which shows how the +rt request works in combination with mk. + +.2c +Starting here, text is typeset in two columns. +Note that this implementation isn't robust +and thus not suited for a real two-column +macro. +@endExample + +Result: + +@Example +This is a small test which shows how the +rt request works in combination with mk. + +Starting here, isn't robust +text is typeset and thus not +in two columns. suited for a +Note that this real two-column +implementation macro. @endExample -@end ignore @endDefreq The following escapes give fine control of movements about the page. -@cindex vertical motion -@cindex motion, vertical @Defesc {\\v, ', e, '} -The @code{\v'@var{e}'} escape enables arbitrary vertical motion from the -current location on the page. The argument@w{ }@var{e} specifies the -distance to move; positive is downwards and negative upwards. The -default unit for this escape @samp{v}. Beware, however, that -@code{gtroff} continues text processing at the point where the motion -ends, so you should always balance motions to avoid interference with -text processing. +@cindex vertical motion (@code{\v}) +@cindex motion, vertical (@code{\v}) +Move vertically, usually from the current location on the page (if no +absolute position operator @samp{|} is used). The +argument@w{ }@var{e} specifies the distance to move; positive is +downwards and negative upwards. The default scaling indicator for this +escape is @samp{v}. Beware, however, that @code{gtroff} continues text +processing at the point where the motion ends, so you should always +balance motions to avoid interference with text processing. + +@code{\v} doesn't trigger a trap. This can be quite useful; for example, +consider a page bottom trap macro which prints a marker in the margin to +indicate continuation of a footnote or something similar. @endDefesc -There are some special case escapes for vertical motion. +There are some special-case escapes for vertical motion. -@ftable @code -@item \r -move upwards@w{ }1@dmn{v}. +@Defesc {\\r, , , } +Move upwards@w{ }1@dmn{v}. +@endDefesc -@item \u -move upwards@w{ }.5@dmn{v}. +@Defesc {\\u, , , } +Move upwards@w{ }.5@dmn{v}. +@endDefesc -@item \d -move down@w{ }.5@dmn{v}. -@end ftable +@Defesc {\\d, , , } +Move down@w{ }.5@dmn{v}. +@endDefesc -@cindex inserting horizontal space -@cindex horizontal space -@cindex space, horizontal @Defesc {\\h, ', e, '} -The @code{\h'@var{e}'} escape provides horizontal motions. The -expression@w{ }@var{e} indicates how far to move: positive is rightwards -and negative leftwards. -@c XXX Is there a default unit for this? +@cindex inserting horizontal space (@code{\h}) +@cindex horizontal space (@code{\h}) +@cindex space, horizontal (@code{\h}) +@cindex horizontal motion (@code{\h}) +@cindex motion, horizontal (@code{\h}) +Move horizontally, usually from the current location (if no absolute +position operator @samp{|} is used). The expression@w{ }@var{e} +indicates how far to move: positive is rightwards and negative +leftwards. The default scaling indicator for this escape is @samp{m}. @endDefesc -There are a number of special case escapes for horizontal motion: +There are a number of special-case escapes for horizontal motion. -@ftable @code -@item \@key{SP} +@Defesc {\\@key{SP}, , , } +@cindex space, unbreakable +@cindex unbreakable space An unbreakable and unpaddable (i.e.@: not expanded during filling) space. (Note: This is a backslash followed by a space.) +@endDefesc -@item \~ +@Defesc {\\~, , , } An unbreakable space that stretches like a normal inter-word space when a line is adjusted. +@endDefesc -@item \| -A 1/6@dmn{th} em space. Ignored for tty output devices (rounded to +@Defesc {\\|, , , } +A 1/6@dmn{th} em space. Ignored for TTY output devices (rounded to zero). +@endDefesc -@item \^ -A 1/12@dmn{th} em space. Ignored for tty output devices (rounded to +@Defesc {\\^, , , } +A 1/12@dmn{th} em space. Ignored for TTY output devices (rounded to zero). +@endDefesc -@item \0 +@Defesc {\\0, , , } +@cindex space, width of a digit (@code{\0}) +@cindex digit width space (@code{\0}) A space the size of a digit. - -@item \& -@cindex zero width space character -@cindex character, zero width space -@cindex space character, zero width -A zero width space. - -@item \) -Like @code{\&} except that it behaves like a character declared with the -@code{cflags} request to be transparent for the purposes of end of -sentence recognition. -@end ftable +@endDefesc The following string sets the @TeX{} logo: @@ -7520,21 +10103,23 @@ The following string sets the @TeX{} logo: .ds TeX T\h'-.1667m'\v'.224m'E\v'-.224m'\h'-.125m'X @endExample -@cindex width escape -@cindex escape, width -@Defesc {\\w, ', text, '} -Used as @code{\w'@var{text}'}, -returns the width of the specified @var{text} in basic units. +@DefescList {\\w, ', text, '} +@DefregItem {st} +@DefregItem {sb} +@DefregItem {rst} +@DefregItem {rsb} +@DefregItem {ct} +@DefregItem {ssc} +@DefregListEnd {skw} +@cindex width escape (@code{\w}) +Return the width of the specified @var{text} in basic units. This allows horizontal movement based on the width of some arbitrary text (e.g.@: given as an argument to a macro). -@c XXX example - -@ignore @Example -... strlen example ... +The length of the string `abc' is \w'abc'u. + @result{} The length of the string `abc' is 72u. @endExample -@end ignore Font changes may occur in @var{text} which don't affect current settings. @@ -7544,60 +10129,107 @@ After use, @code{\w} sets several registers: @table @code @item st @itemx sb -@vindex st -@vindex sb -The highest and lowest point, respectively, in @var{text}. +The highest and lowest point of the baseline, respectively, in @var{text}. @item rst @itemx rsb -@vindex rst -@vindex rsb Like the @code{st} and @code{sb} registers, but takes account of the -heights and depths of characters. +heights and depths of glyphs. With other words, this gives the +highest and lowest point of @var{text}. @item ct -@vindex ct -Defines the kinds of characters occurring in @var{text}: +Defines the kinds of glyphs occurring in @var{text}: @table @asis @item 0 -only short characters, no descenders or tall characters. +only short glyphs, no descenders or tall glyphs. @item 1 at least one descender. @item 2 -at least one tall character. +at least one tall glyph. @item 3 -at least one each of a descender and a tall character. +at least one each of a descender and a tall glyph. @end table @item ssc -@vindex ssc The amount of horizontal space (possibly negative) that should be added -to the last character before a subscript. +to the last glyph before a subscript. @item skw -@vindex skw -How far to right of the center of the last character in the @code{\w} +How far to right of the center of the last glyph in the @code{\w} argument, the center of an accent from a roman font should be placed -over that character. +over that glyph. @end table @endDefesc -@Defesc {\\k, ', x, '} -Stores the current horizontal position in register @var{x}. -Use this, for example, to return to the beginning of a string -for highlighting or other decoration. +@DefescList {\\k, , p, } +@DefescItem {\\k, @lparen{}, ps, } +@DefescListEnd {\\k, @lbrack{}, position, @rbrack} +@cindex saving horizontal input line position (@code{\k}) +@cindex horizontal input line position, saving (@code{\k}) +@cindex input line position, horizontal, saving (@code{\k}) +@cindex position, horizontal input line, saving (@code{\k}) +@cindex line, input, horizontal position, saving (@code{\k}) +Store the current horizontal position in the @emph{input} line in +number register with name @var{position} (one-character name@w{ }@var{p}, +two-character name @var{ps}). Use this, for example, to return to the +beginning of a string for highlighting or other decoration. @endDefesc +@Defreg {hp} +@cindex horizontal input line position register (@code{hp}) +@cindex input line, horizontal position, register (@code{hp}) +@cindex position, horizontal, in input line, register (@code{hp}) +@cindex line, input, horizontal position, register (@code{hp}) +The current horizontal position at the input line. +@endDefreg + @Defreg {.k} +@cindex horizontal output line position register (@code{.k}) +@cindex output line, horizontal position, register (@code{.k}) +@cindex position, horizontal, in output line, register (@code{.k}) +@cindex line, output, horizontal position, register (@code{.k}) A read-only number register containing the current horizontal output position. @endDefreg -@c XXX documentation +@Defesc {\\o, ', @Var{a}@Var{b}@Var{c}, '} +@cindex overstriking glyphs (@code{\o}) +@cindex glyphs, overstriking (@code{\o}) +Overstrike glyphs @var{a}, @var{b}, @var{c}, @dots{}; the glyphs +are centered, and the resulting spacing is the largest width of the +affected glyphs. +@endDefesc + +@Defesc {\\z, , g, , } +@cindex zero-width printing (@code{\z}, @code{\Z}) +@cindex printing, zero-width (@code{\z}, @code{\Z}) +Print glyph @var{g} with zero width, i.e., without spacing. Use +this to overstrike glyphs left-aligned. +@endDefesc + +@Defesc {\\Z, ', anything, '} +@cindex zero-width printing (@code{\z}, @code{\Z}) +@cindex printing, zero-width (@code{\z}, @code{\Z}) +Print @var{anything}, then restore the horizontal and vertical position. +The argument may not contain tabs or leaders. + +The following is an example of a strike-through macro: + +@Example +.de ST +.nr ww \w'\\$1' +\Z@@\v'-.25m'\l'\\n[ww]u'@@\\$1 +.. +. +This is +.ST "a test" +an actual emergency! +@endExample +@endDefesc @c ===================================================================== @@ -7617,188 +10249,251 @@ information. All drawing is done via escapes. -@cindex drawing horizontal lines -@cindex horizontal line, drawing -@cindex line, horizontal, drawing -@Defesc {\\l, ', l c, '} -Draws a line rightwards from the current -location. The full syntax for this escape is: - -@Example -\l'@var{l}@var{c}' -@endExample - -@noindent -where @var{l} is the length of the line to be drawn, starting at the -current location; positive numbers draw to the right, and negative -numbers draw towards the left. This can also be specified absolutely -(i.e.@: with a leading @samp{|}) which draws back to the beginning -of the line. - -@cindex underscore character -@cindex character, underscore -@cindex line drawing character -@cindex character for line drawing -The optional second parameter @var{c} is a character to draw the line +@DefescList {\\l, ', @Var{l}, '} +@DefescListEnd {\\l, ', @Var{l}@Var{g}, '} +@cindex drawing horizontal lines (@code{\l}) +@cindex horizontal line, drawing (@code{\l}) +@cindex line, horizontal, drawing (@code{\l}) +Draw a line horizontally. @var{l} is the length of the line to be +drawn. If it is positive, start the line at the current location and +draw to the right; its end point is the new current location. Negative +values are handled differently: The line starts at the current location +and draws to the left, but the current location doesn't move. + +@var{l} can also be specified absolutely (i.e.@: with a leading +@samp{|}) which draws back to the beginning of the input line. +Default scaling indicator is @samp{m}. + +@cindex underscore glyph (@code{\[ru]}) +@cindex glyph, underscore (@code{\[ru]}) +@cindex line drawing glyph +@cindex glyph, for line drawing +The optional second parameter@w{ }@var{g} is a glyph to draw the line with. If this second argument is not specified, @code{gtroff} uses -the underscore character. +the underscore glyph, @code{\[ru]}. -@cindex zero width space character -@cindex character, zero width space -@cindex space character, zero width -@esindex \& +@cindex zero width space character (@code{\&}) +@cindex character, zero width space (@code{\&}) +@cindex space character, zero width (@code{\&}) To separate the two arguments (to prevent @code{gtroff} from -interpreting a drawing character as a scaling indicator) use @code{\&}. +interpreting a drawing glyph as a scaling indicator if the glyph is +represented by a single character) use @code{\&}. Here a small useful example: @Example .de box -\(br\\$*\(br\l'|0\(rn'\l'|0\(ul' +\[br]\\$*\[br]\l'|0\[rn]'\l'|0\[ul]' .. @endExample -@opindex | @noindent Note that this works by outputting a box rule (a vertical line), then -the text given as an argument and then another box rule. Then the line -drawing escapes both draw from the current location to the beginning of -the @emph{input} line. +the text given as an argument and then another box rule. Finally, the +line drawing escapes both draw from the current location to the +beginning of the @emph{input} line -- this works because the line +length is negative, not moving the current point. @endDefesc -@cindex drawing vertical lines -@cindex vertical line drawing -@cindex line, vertical, drawing -@cindex line drawing character -@cindex character for line drawing -@cindex box rule character -@cindex character, box rule -@Defesc {\\L, ', l c, '} -Draws vertical lines. Its parameters are -similar to the @code{\l} escape. The -movement is downwards for positive values, -and upwards for negative values. The -default character is the box rule character. As with the vertical -motion escapes, text processing blindly continues where the line -ends. - -@c XXX example +@DefescList {\\L, ', @Var{l}, '} +@DefescListEnd {\\L, ', @Var{l}@Var{g}, '} +@cindex drawing vertical lines (@code{\L}) +@cindex vertical line drawing (@code{\L}) +@cindex line, vertical, drawing (@code{\L}) +@cindex line drawing glyph +@cindex glyph for line drawing +@cindex box rule glyph (@code{\[br]}) +@cindex glyph, box rule (@code{\[br]}) +Draw vertical lines. Its parameters are +similar to the @code{\l} escape, except that the default scaling +indicator is @samp{v}. The movement is downwards for positive values, +and upwards for negative values. The default glyph is the box rule +glyph, @code{\[br]}. As with the vertical motion escapes, text +processing blindly continues where the line ends. -@ignore @Example -...box macro... +This is a \L'3v'test. +@endExample + +@noindent +Here the result, produced with @code{grotty}. + +@Example +This is a + | + | + |test. @endExample -@end ignore @endDefesc @Defesc {\\D, ', command arg @dots{}, '} The @code{\D} escape provides a variety of drawing functions. -While the previous escapes work on a character device, these -escapes do not. +Note that on character devices, only vertical and horizontal lines are +supported within @code{grotty}; other devices may only support a subset +of the available drawing functions. + +The default scaling indicator for all subcommands of @code{\D} is +@samp{m} for horizontal distances and @samp{v} for vertical ones. +Exceptions are @w{@code{\D'f @dots{}'}} and @w{@code{\D't @dots{}'}} +which use @code{u} as the default. @table @code @item \D'l @var{dx} @var{dy}' +@cindex line, drawing (@w{@code{\D'l @dots{}'}}) +@cindex drawing a line (@w{@code{\D'l @dots{}'}}) Draw a line from the current location to the relative point specified by (@var{dx},@var{dy}). -@c XXX example - -@ignore -@Example -...revised box macro... +The following example is a macro for creating a box around a text string; +for simplicity, the box margin is taken as a fixed value, 0.2@dmn{m}. + +@Example +.de BOX +. nr @@wd \w'\\$1' +\h'.2m'\ +\h'-.2m'\v'(.2m - \\n[rsb]u)'\ +\D'l 0 -(\\n[rst]u - \\n[rsb]u + .4m)'\ +\D'l (\\n[@@wd]u + .4m) 0'\ +\D'l 0 (\\n[rst]u - \\n[rsb]u + .4m)'\ +\D'l -(\\n[@@wd]u + .4m) 0'\ +\h'.2m'\v'-(.2m - \\n[rsb]u)'\ +\\$1\ +\h'.2m' +.. @endExample -@end ignore + +@noindent +First, the width of the string is stored in register @code{@@wd}. Then, +four lines are drawn to form a box, properly offset by the box margin. +The registers @code{rst} and @code{rsb} are set by the @code{\w} escape, +containing the largest height and depth of the whole string. @item \D'c @var{d}' -@cindex circle drawing -@cindex drawing a circle -Draw a circle with a diameter of @var{d} with the leftmost point at the +@cindex circle, drawing (@w{@code{\D'c @dots{}'}}) +@cindex drawing a circle (@w{@code{\D'c @dots{}'}}) +Draw a circle with a diameter of@w{ }@var{d} with the leftmost point at the current position. @item \D'C @var{d}' -Draw a solid circle with the same parameters as an outlined circle. - -@item \D'e @var{dx} @var{dy}' -@cindex drawing an ellipse -@cindex ellipse drawing -Draw an ellipse with a horizontal diameter of @var{dx} and a vertical -diameter of @var{dy} with the leftmost point at the current position. - -@item \D'E @var{dx} @var{dy}' +@cindex circle, solid, drawing (@w{@code{\D'C @dots{}'}}) +@cindex drawing a solid circle (@w{@code{\D'C @dots{}'}}) +@cindex solid circle, drawing (@w{@code{\D'C @dots{}'}}) +Draw a solid circle with the same parameters as an outlined circle. No +outline is drawn. + +@item \D'e @var{x} @var{y}' +@cindex drawing an ellipse (@w{@code{\D'e @dots{}'}}) +@cindex ellipse, drawing (@w{@code{\D'e @dots{}'}}) +Draw an ellipse with a horizontal diameter of @var{x} and a vertical +diameter of @var{y} with the leftmost point at the current position. + +@item \D'E @var{x} @var{y}' +@cindex ellipse, solid, drawing (@w{@code{\D'E @dots{}'}}) +@cindex drawing a solid ellipse (@w{@code{\D'E @dots{}'}}) +@cindex solid ellipse, drawing (@w{@code{\D'E @dots{}'}}) Draw a solid ellipse with the same parameters as an outlined ellipse. +No outline is drawn. @item \D'a @var{dx1} @var{dy1} @var{dx2} @var{dy2}' -@cindex arc drawing -@cindex drawing an arc +@cindex arc, drawing (@w{@code{\D'a @dots{}'}}) +@cindex drawing an arc (@w{@code{\D'a @dots{}'}}) Draw an arc clockwise from the current location through the two -specified locations (@var{dx1},@var{dy1}) and (@var{dx2},@var{dy2}). +specified relative locations (@var{dx1},@var{dy1}) and +(@var{dx2},@var{dy2}). The coordinates of the first point are relative +to the current position, and the coordinates of the second point are +relative to the first point. -@item \D'~ @var{dx1} @var{dy1} @var{dx2} @var{dy2} ...' -@cindex drawing a spline -@cindex spline drawing -Draw a spline from the current location to (@var{dx1},@var{dy1}) and -then to (@var{dx2},@var{dy2}), and so on. +@item \D'~ @var{dx1} @var{dy1} @var{dx2} @var{dy2} @dots{}' +@cindex drawing a spline (@w{@code{\D'~ @dots{}'}}) +@cindex spline, drawing (@w{@code{\D'~ @dots{}'}}) +Draw a spline from the current location to the relative point +(@var{dx1},@var{dy1}) and then to (@var{dx2},@var{dy2}), and so on. @item \D'f @var{n}' -@cindex gray shading -@cindex shading -@cindex shades for filling objects +@cindex gray shading (@w{@code{\D'f @dots{}'}}) +@cindex shading filled objects (@w{@code{\D'f @dots{}'}}) Set the shade of gray to be used for filling solid objects to@w{ }@var{n}; @var{n}@w{ }must be an integer between 0 and@w{ }1000, where 0 corresponds solid white and 1000 to solid black, and values in between correspond to intermediate shades of gray. This applies only to solid -circles, solid ellipses and solid polygons. By default, a level of@w{ -}1000 is used. - -@item \D'p @var{dx1} @var{dy1} @var{dx2} @var{dy2} ...' -@cindex drawing a polygon -@cindex polygon drawing -Draw a polygon from the current location to (@var{dx1},@var{dy1}) and -then to (@var{dx2},@var{dy2}) and so on. When the specified data points -are exhausted, a line is drawn back to the starting point. - -@c XXX example - -@ignore -@Example -... box example (yes, again)... -@endExample -@end ignore - -@item \D'P @var{dx1} @var{dy1} @var{dx2} @var{dy2} ...' +circles, solid ellipses, and solid polygons. By default, a level of +1000 is used. + +@item \D'p @var{dx1} @var{dy1} @var{dx2} @var{dy2} @dots{}' +@cindex drawing a polygon (@w{@code{\D'p @dots{}'}}) +@cindex polygon, drawing (@w{@code{\D'p @dots{}'}}) +Draw a polygon from the current location to the relative position +(@var{dx1},@var{dy1}) and then to (@var{dx2},@var{dy2}) and so on. +When the specified data points are exhausted, a line is drawn back +to the starting point. + +@item \D'P @var{dx1} @var{dy1} @var{dx2} @var{dy2} @dots{}' +@cindex polygon, solid, drawing (@w{@code{\D'P @dots{}'}}) +@cindex drawing a solid polygon (@w{@code{\D'P @dots{}'}}) +@cindex solid polygon, drawing (@w{@code{\D'P @dots{}'}}) Draw a solid polygon with the same parameters as an outlined polygon. - -@c XXX example - -@ignore -@Example -... shaded box example ... +No outline is drawn. + +Here a better variant of the box macro to fill the box with some color. +Note that the box must be drawn before the text since colors in +@code{gtroff} are not transparent; the filled polygon would hide the +text completely. + +@Example +.de BOX +. nr @@wd \w'\\$1' +\h'.2m'\ +\h'-.2m'\v'(.2m - \\n[rsb]u)'\ +\M[lightcyan]\ +\D'P 0 -(\\n[rst]u - \\n[rsb]u + .4m) \ + (\\n[@@wd]u + .4m) 0 \ + 0 (\\n[rst]u - \\n[rsb]u + .4m) \ + -(\\n[@@wd]u + .4m) 0'\ +\h'.2m'\v'-(.2m - \\n[rsb]u)'\ +\M[]\ +\\$1\ +\h'.2m' +.. @endExample -@end ignore @item \D't @var{n}' -@cindex line thickness -@cindex thickness of lines -Set the current line thickness to @var{n} machine units. A value of +@cindex line thickness (@w{@code{\D't @dots{}'}}) +@cindex thickness of lines (@w{@code{\D't @dots{}'}}) +Set the current line thickness to @var{n}@w{ }machine units. A value of zero selects the smallest available line thickness. A negative value makes the line thickness proportional to the current point size (this is -the default behaviour of @code{ditroff}). +the default behaviour of @acronym{AT&T} @code{troff}). @end table @endDefesc -@cindex pile, character -@cindex character pile +@xref{Graphics Commands}. + @Defesc {\\b, ', string, '} -@dfn{Piles} a sequence of characters -vertically, and centers it vertically on the current line. Use it -to build large brackets and braces. +@cindex pile, glyph (@code{\b}) +@cindex glyph pile (@code{\b}) +@cindex stacking glyphs (@code{\b}) +@dfn{Pile} a sequence of glyphs vertically, and center it vertically +on the current line. Use it to build large brackets and braces. + +Here an example how to create a large opening brace: @Example -\b'\(lt\(bv\(lk\(bv\(lb' +\b'\[lt]\[bv]\[lk]\[bv]\[lb]' @endExample -@endDefesc -@xref{Drawing Functions}. +@cindex @code{\b}, limitations +@cindex limitations of @code{\b} escape +The first glyph is on the top, the last glyph in @var{string} is +at the bottom. Note that @code{gtroff} separates the glyphs +vertically by 1@dmn{m}, and the whole object is centered 0.5@dmn{m} +above the current baseline; the largest glyph width is used as the +width for the whole object. This rather unflexible positioning +algorithm doesn't work with @option{-Tdvi} since the bracket pieces vary +in height for this device. Instead, use the @code{eqn} preprocessor. + +@xref{Manipulating Spacing}, how to adjust the vertical spacing with +the @code{\x} escape. +@endDefesc @c ===================================================================== @@ -7809,13 +10504,22 @@ to build large brackets and braces. @dfn{Traps} are locations, which, when reached, call a specified macro. These traps can occur at a given location on the page, at a -given location in the current diversion, after a certain number of input -lines or at the end of input. +given location in the current diversion, at a blank line, +after a certain number of input lines, or at the end of input. + +@cindex planting a trap +@cindex trap, planting +Setting a trap is also called @dfn{planting}. +@cindex trap, springing +@cindex springing a trap +It is also said that a trap is @dfn{sprung} if the associated macro +is executed. @menu * Page Location Traps:: * Diversion Traps:: * Input Line Traps:: +* Blank Line Traps:: * End-of-input Traps:: @end menu @@ -7827,8 +10531,8 @@ lines or at the end of input. @cindex traps, page location @dfn{Page location traps} perform an action when @code{gtroff} -reaches a certain vertical location on the page. Page location -traps have a variety of purposes, including: +reaches or passes a certain vertical location on the page. Page +location traps have a variety of purposes, including: @itemize @item @@ -7841,10 +10545,12 @@ setting body text in multiple columns setting footnotes @end itemize -@cindex vertical position trap enable register -@Defreq {vpt, flag} -@Defregx {.vpt} -Enables vertical position traps if @var{flag} is non-zero, or disables +@DefreqList {vpt, flag} +@DefregListEnd {.vpt} +@cindex enabling vertical position traps (@code{vpt}) +@cindex vertical position traps, enabling (@code{vpt}) +@cindex vertical position trap enable register (@code{.vpt}) +Enable vertical position traps if @var{flag} is non-zero, or disables them otherwise. Vertical position traps are traps set by the @code{wh} or @code{dt} requests. Traps set by the @code{it} request are not vertical position traps. The parameter that controls whether vertical @@ -7853,13 +10559,15 @@ are enabled. The current setting of this is available in the @code{.vpt} read-only number register. @endDefreq -@Defreq {wh, dist macro} -Sets a page location trap. Positive values for @var{dist} set +@Defreq {wh, dist [@Var{macro}]} +Set a page location trap. Positive values for @var{dist} set the trap relative to the top of the page; negative values set -the trap relative to the bottom of the page. +the trap relative to the bottom of the page. Default scaling +indicator is @samp{v}. @var{macro} is the name of the macro to execute when the -trap is sprung. +trap is sprung. If @var{macro} is missing, remove the first trap +(if any) at @var{dist}. @cindex page headers @cindex page footers @@ -7870,35 +10578,85 @@ set headers and footers. @Example .de hd \" Page header -'sp .5i -.tl 'Title''date' -'sp .3i +' sp .5i +. tl 'Title''date' +' sp .3i .. +. .de fo \" Page footer -'sp 1v -.tl ''%'' -'bp +' sp 1v +. tl ''%'' +' bp .. +. .wh 0 hd \" trap at top of the page .wh -1i fo \" trap one inch from bottom @endExample + +A trap at or below the bottom of the page is ignored; it can be made +active by either moving it up or increasing the page length so that the +trap is on the page. + +It is possible to have more than one trap at the same location; to do so, +the traps must be defined at different locations, then moved together with +the @code{ch} request; otherwise the second trap would replace the first +one. Earlier defined traps hide later defined traps if moved to the same +position (the many empty lines caused by the @code{bp} request are omitted): + +@Example +.de a +. nop a +.. +.de b +. nop b +.. +.de c +. nop c +.. +. +.wh 1i a +.wh 2i b +.wh 3i c +.bp + @result{} a b c +@endExample +@Example +.ch b 1i +.ch c 1i +.bp + @result{} a +@endExample +@Example +.ch a 0.5i +.bp + @result{} a b +@endExample @endDefreq -@cindex distance to next trap -@cindex trap, distance @Defreg {.t} +@cindex distance to next trap register (@code{.t}) +@cindex trap, distance, register (@code{.t}) A read-only number register holding the distance to the next trap. + +If there are no traps between the current position and the bottom of the +page, it contains the distance to the page bottom. In a diversion, the +distance to the page bottom is infinite (the returned value is the biggest +integer which can be represented in @code{groff}) if there are no diversion +traps. @endDefreg -@cindex changing trap location -@cindex trap, changing location -@Defreq {ch, dist macro} -Changes the location of a trap. +@Defreq {ch, macro dist} +@cindex changing trap location (@code{ch}) +@cindex trap, changing location (@code{ch}) +Change the location of a trap. The first argument is the name of the macro to be invoked at the trap, and the second argument is the new location for the trap -(note that the parameters are specified the opposite of the @code{.wh} request). -This is useful for building up footnotes in a diversion to allow more -space at the bottom of the page for them. +(note that the parameters are specified the opposite of the @code{wh} +request). This is useful for building up footnotes in a diversion to +allow more space at the bottom of the page for them. + +Default scaling indicator for @var{dist} is @samp{v}. If @var{dist} +is missing, the trap is removed. @c XXX @@ -7916,9 +10674,9 @@ sprung. Useful in conjunction with the @code{.trunc} register. @xref{Page Control}, for more information. @endDefreg -@rqindex ne -@cindex @code{ne}, and the @code{.trunc} register @Defreg {.trunc} +@cindex @code{ne} request, and the @code{.trunc} register +@cindex truncated vertical space register (@code{.trunc}) A read-only register containing the amount of vertical space truncated by the most recently sprung vertical position trap, or, if the trap was sprung by an @code{ne} request, minus the amount of vertical motion @@ -7935,28 +10693,34 @@ actually is. @cindex diversion traps @cindex traps, diversion -@vindex .t -@cindex @code{.t}, and diversions @Defreq {dt, dist macro} -Sets a trap @emph{within} a diversion. -@var{dist} is the first argument is the location of the trap -(identical to the @code{.wh} request) -and @var{macro} is the name of the macro to be invoked. The +@cindex @code{.t} register, and diversions +@cindex setting diversion trap (@code{dt}) +@cindex diversion trap, setting (@code{dt}) +@cindex trap, diversion, setting (@code{dt}) +Set a trap @emph{within} a diversion. +@var{dist} is the location of the trap +(identical to the @code{.wh} request; default scaling indicator is +@samp{v}) and @var{macro} is the name of the macro to be invoked. The number register @code{.t} still works within diversions. @xref{Diversions}, for more information. @endDefreq @c --------------------------------------------------------------------- -@node Input Line Traps, End-of-input Traps, Diversion Traps, Traps +@node Input Line Traps, Blank Line Traps, Diversion Traps, Traps @subsection Input Line Traps @cindex input line traps @cindex traps, input line -@Defreq {it, n macro} -Sets an input line trap. -@var{n} is the number of lines of input which may be read before -@dfn{springing} the trap, @var{macro} is the macro to be invoked. +@DefreqList {it, n macro} +@DefreqItem {itc, n macro} +@cindex setting input line trap (@code{it}) +@cindex input line trap, setting (@code{it}) +@cindex trap, input line, setting (@code{it}) +Set an input line trap. +@var{n}@w{ }is the number of lines of input which may be read before +springing the trap, @var{macro} is the macro to be invoked. Request lines are not counted as input lines. For example, one possible use is to have a macro which prints the @@ -7964,26 +10728,58 @@ next @var{n}@w{ }lines in a bold font. @Example .de B -.it \\$1 B-end -.ft B +. it \\$1 B-end +. ft B .. +. .de B-end -.ft R +. ft R .. @endExample + +@cindex input line traps and interrupted lines (@code{itc}) +@cindex interrupted lines and input line traps (@code{itc}) +@cindex traps, input line, and interrupted lines (@code{itc}) +@cindex lines, interrupted, and input line traps (@code{itc}) +The @code{itc} request is identical, +except that a line interrupted with @code{\c} +counts as one input line. + +Both requests are associated with the current environment +(@pxref{Environments}); switching to another environment disables the +current input trap, and going back reactivates it, restoring the number +of already processed lines. @endDefreq @c --------------------------------------------------------------------- -@node End-of-input Traps, , Input Line Traps, Traps +@node Blank Line Traps, End-of-input Traps, Input Line Traps, Traps +@subsection Blank Line Traps +@cindex blank line traps +@cindex traps, blank line + +@Defreq {blm, macro} +@cindex blank line macro (@code{blm}) +Set a blank line trap. +@code{gtroff} executes @var{macro} when it encounters a blank line in +the input file. +@endDefreq + +@c --------------------------------------------------------------------- + +@node End-of-input Traps, , Blank Line Traps, Traps @subsection End-of-input Traps @cindex end-of-input traps @cindex traps, end-of-input @Defreq {em, macro} -Sets a trap at the end of input. The @var{macro} -specified is executed after the last line of the -input file has been processed. +@cindex setting end-of-input trap (@code{em}) +@cindex end-of-input trap, setting (@code{em}) +@cindex trap, end-of-input, setting (@code{em}) +@cindex end-of-input macro (@code{em}) +@cindex macro, end-of-input (@code{em}) +Set a trap at the end of input. @var{macro} is executed after the +last line of the input file has been processed. For example, if the document had to have a section at the bottom of the last page for someone to approve it, the @code{em} request could be @@ -7991,15 +10787,16 @@ used. @Example .de approval -.ne 5v -.sp |(\\n(.t-6v) -.in +4i -.lc _ -.br +. ne 5v +. sp |(\\n[.t] - 6v) +. in +4i +. lc _ +. br Approved:\t\a -.sp +. sp Date:\t\t\a .. +. .em approval @endExample @endDefreq @@ -8015,34 +10812,79 @@ In @code{gtroff} it is possible to @dfn{divert} text into a named storage area. Due to the similarity to defining macros it is sometimes said to be stored in a macro. This is used for saving text for output at a later time, which is useful for keeping blocks of text on the same -page, footnotes, tables of contents and indices. - -@c XXX describe top-level diversion -@c XXX index entry for top-level diversion +page, footnotes, tables of contents, and indices. -@Defreq {di, macro} -@Defreqx {da, macro} -Begins a diversion. Like the @code{de} +@cindex top-level diversion +@cindex diversion, top-level +For orthogonality it is said that @code{gtroff} is in the @dfn{top-level +diversion} if no diversion is active (i.e., the data is diverted to the +output device). + +@DefreqList {di, macro} +@DefreqListEnd {da, macro} +@cindex beginning diversion (@code{di}) +@cindex diversion, beginning (@code{di}) +@cindex ending diversion (@code{di}) +@cindex diversion, ending (@code{di}) +@cindex appending to a diversion (@code{da}) +@cindex diversion, appending (@code{da}) +Begin a diversion. Like the @code{de} request, it takes an argument of a macro name to divert subsequent text into. The @code{da} macro appends to an existing diversion. @code{di} or @code{da} without an argument ends the diversion. +@endDefreq -@c XXX example +@DefreqList {box, macro} +@DefreqListEnd {boxa, macro} +Begin (or appends to) a diversion like the +@code{di} and @code{da} requests. +The difference is that @code{box} and @code{boxa} +do not include a partially-filled line in the diversion. + +Compare this: -@ignore @Example -... end-note example ... +Before the box. +.box xxx +In the box. +.br +.box +After the box. +.br + @result{} Before the box. After the box. +.xxx + @result{} In the box. @endExample -@end ignore + +@noindent +with this: + +@Example +Before the diversion. +.di yyy +In the diversion. +.br +.di +After the diversion. +.br + @result{} After the diversion. +.yyy + @result{} Before the diversion. In the diversion. +@endExample + +@code{box} or @code{boxa} without an argument ends the diversion. @endDefreq -@vindex nl -@vindex .h +@DefregList {.z} +@DefregListEnd {.d} +@cindex @code{nl} register, and @code{.d} @cindex nested diversions @cindex diversion, nested -@Defreg {.z} -@Defregx {.d} +@cindex diversion name register (@code{.z}) +@cindex vertical position in diversion register (@code{.d}) +@cindex position, vertical, in diversion, register (@code{.d}) +@cindex diversion, vertical position in, register (@code{.d}) Diversions may be nested. The read-only number register @code{.z} contains the name of the current diversion (this is a string-valued register). The read-only number register @code{.d} contains the current @@ -8050,60 +10892,86 @@ vertical place in the diversion. If not in a diversion it is the same as the register @code{nl}. @endDefreg -@c XXX more info - @Defreg {.h} +@cindex high-water mark register (@code{.h}) +@cindex mark, high-water, register (@code{.h}) +@cindex position of lowest text line (@code{.h}) +@cindex text line, position of lowest (@code{.h}) The @dfn{high-water mark} on the current page. It corresponds to the text baseline of the lowest line on the page. This is a read-only register. + +@Example +.tm .h==\n[.h], nl==\n[nl] + @result{} .h==0, nl==-1 +This is a test. +.br +.sp 2 +.tm .h==\n[.h], nl==\n[nl] + @result{} .h==40, nl==120 +@endExample + +@cindex @code{.h} register, difference to @code{nl} +@cindex @code{nl} register, difference to @code{.h} +@noindent +As can be seen in the previous example, empty lines are not considered +in the return value of the @code{.h} register. @endDefreg -@Defreg {dn} -@Defregx {dl} +@DefregList {dn} +@DefregListEnd {dl} After completing a diversion, the read-write number registers @code{dn} and @code{dl} contain the vertical and horizontal size of the diversion. -@example -@group +@Example .\" Center text both horizontally & vertically +. +.\" Enclose macro definitions in .eo and .ec +.\" to avoid the doubling of the backslash +.eo +.\" macro .(c starts centering mode .de (c -.br -.nf -.di @@c +. br +. ev (c +. evc 0 +. in 0 +. nf +. di @@c .. -@end group -@group +@endExample +@Example +.\" macro .)c terminates centering mode .de )c -.br -.di -.nr @@s (((\\n(.tu-\\n(dnu)/2u)-1v) -.sp \\n(@@su -.ce 1000 -.nf -.@c -.br -.ce 0 -.sp \\n(@@su -.br -.fi -.rr @@s +. br +. ev +. di +. nr @@s (((\n[.t]u - \n[dn]u) / 2u) - 1v) +. sp \n[@@s]u +. ce 1000 +. @@c +. ce 0 +. sp \n[@@s]u +. br +. fi +. rr @@s +. rm @@s +. rm @@c .. -@end group -@end example +.\" End of macro definitions, restore escape mechanism +.ec +@endExample @endDefreg -@cindex transparent output -@cindex output, transparent -@Defesc {\\!, , , } -@Defescx {\\?, , @Var{anything}, \\?} -Prevents requests, macros and escapes from being +@DefescList {\\!, , , } +@DefescListEnd {\\?, , @Var{anything}, \\?} +@cindex transparent output (@code{\!}, @code{\?}) +@cindex output, transparent (@code{\!}, @code{\?}) +Prevent requests, macros, and escapes from being interpreted when read into a diversion. This takes the given text and @dfn{transparently} embeds it into the diversion. This is useful for macros which shouldn't be invoked until the diverted text is actually output. -@c XXX anything is read in copy mode. (what about \! ??) - The @code{\!} escape transparently embeds text up to and including the end of the line. The @code{\?} escape transparently embeds text until the next @@ -8117,7 +10985,7 @@ occurrence of the @code{\?} escape. For example: @var{anything} may not contain newlines; use @code{\!} to embed newlines in a diversion. The escape sequence @code{\?} is also recognized in copy mode and turned into a single internal code; it is -this code that terminates anything. Thus the following example +this code that terminates @var{anything}. Thus the following example prints@w{ }4. @Example @@ -8137,16 +11005,52 @@ prints@w{ }4. .nr x 4 .f @endExample + +Both escapes read the data in copy mode. + +@cindex @code{\!}, in top-level diversion +@cindex top-level diversion, and @code{\!} +@cindex diversion, top-level, and @code{\!} +If @code{\!} is used in the top-level diversion, its argument is +directly embedded into the @code{gtroff} intermediate output. This can +be used for example to control a postprocessor which processes the data +before it is sent to the device driver. + +@cindex @code{\?}, in top-level diversion +@cindex top-level diversion, and @code{\?} +@cindex diversion, top-level, and @code{\?} +The @code{\?} escape used in the top-level diversion produces no output +at all; its argument is simply ignored. @endDefesc -@cindex unformatting diversions -@cindex diversion, unformatting +@cindex @code{\!}, and @code{output} +@cindex @code{output} request, and @code{\!} +@Defreq {output, string} +Emit @var{string} directly to the @code{gtroff} intermediate output +(subject to copy-mode interpretation); this is similar to @code{\!} used +at the top level. An initial double quote in @var{string} is stripped off +to allow initial blanks. + +This request can't be used before the first page has started -- if you get +an error, simply insert @code{.br} before the @code{output} request. + +Without argument, @code{output} is ignored. + +Use with caution! It is normally only needed for mark-up used by a +postprocessor which does something with the output before sending it to +the output device, filtering out @code{string} again. +@endDefreq + @Defreq {asciify, div} -@dfn{Unformats} the diversion specified by @var{div} -in such a way that @acronym{ASCII} and space characters that +@cindex unformatting diversions (@code{asciify}) +@cindex diversion, unformatting (@code{asciify}) +@cindex @code{trin} request, and @code{asciify} +@dfn{Unformat} the diversion specified by @var{div} +in such a way that @acronym{ASCII} characters, characters translated with +the @code{trin} request, space characters, and some escape sequences that were formatted and diverted are treated like ordinary input characters when the diversion is reread. It can be also used for gross -hacks; for example, the following sets register @code{n} to@w{ }1. +hacks; for example, the following sets register@w{ }@code{n} to@w{ }1. @Example .tr @@. @@ -8162,6 +11066,17 @@ hacks; for example, the following sets register @code{n} to@w{ }1. @xref{Copy-in Mode}. @endDefreq +@Defreq {unformat, div} +Like @code{asciify}, unformat the specified diversion. +However, @code{unformat} only unformats spaces and tabs +between words. +Unformatted tabs are treated as input tokens, +and spaces are stretchable again. + +The vertical size of lines is not preserved; glyph information (font, +font size, space width, etc.)@: is retained. +@endDefreq + @c ===================================================================== @@ -8180,33 +11095,41 @@ following is the information kept in an environment. @itemize @bullet @item -font parameters (size, family, style, character height and slant, space +font parameters (size, family, style, glyph height and slant, space and sentence space size) @item page parameters (line length, title length, vertical spacing, -line spacing, indentation, line numbering, hyphenation data) +line spacing, indentation, line numbering, centering, right-justifying, +underlining, hyphenation data) @item fill and adjust mode @item -tab stops, tab and leader characters, escape character, no-break and -hyphen indicators, margin character data +tab stops, tab and leader characters, escape character, +no-break and hyphen indicators, margin character data @item partially collected lines + +@item +input traps + +@item +drawing and fill colours @end itemize These environments may be given arbitrary names (see @ref{Identifiers}, for more info). Old versions of @code{troff} only had environments -named @samp{0}, @samp{1} and@w{ }@samp{2}. - -@cindex switch environments -@cindex current environment number/name register -@Defreq {ev, env} -@Defregx {.ev} -Switches to another environment. The argument @var{env} is the name of +named @samp{0}, @samp{1}, and @samp{2}. + +@DefreqList {ev, [@Var{env}]} +@DefregListEnd {.ev} +@cindex switching environments (@code{ev}) +@cindex environment, switching (@code{ev}) +@cindex environment number/name register (@code{.ev}) +Switch to another environment. The argument @var{env} is the name of the environment to switch to. With no argument, @code{gtroff} switches back to the previous environment. There is no limit on the number of named environments; they are created the first time that they are @@ -8220,14 +11143,6 @@ active environment onto a stack. If, say, environments @samp{foo}, @samp{bar} (which is popped off the stack), and a second call switches back to environment @samp{foo}. -@c XXX example - -@ignore -@Example -... page break macro, revised ... -@endExample -@end ignore - Here is an example: @Example @@ -8246,27 +11161,77 @@ Here is an example: @endExample @endDefreq -@cindex copy environment @Defreq {evc, env} -Copies the environment @var{env} into the current environment. +@cindex copying environment (@code{evc}) +@cindex environment, copying (@code{evc}) +Copy the environment @var{env} into the current environment. + +The following environment data is not copied: + +@itemize @bullet +@item +Partially filled lines. + +@item +The status whether the previous line was interrupted. + +@item +The number of lines still to center, or to right-justify, or to underline +(with or without underlined spaces); they are set to zero. + +@item +The status whether a temporary indent is active. + +@item +Input traps and its associated data. + +@item +Line numbering mode is disabled; it can be reactivated with +@w{@samp{.nm +0}}. + +@item +The number of consecutive hyphenated lines (set to zero). +@end itemize @endDefreq +@DefregList {.cht} +@DefregItem {.cdp} +@DefregListEnd {.csk} +@cindex environment, last glyph +The @code{\n[.cht]} register contains the +maximum extent (above the baseline) +of the last glyph added to the current environment. + +The @code{\n[.cdp]} register contains the +maximum extent (below the baseline) +of the last glyph added to the current environment. + +The @code{\n[.csk]} register contains the +@dfn{skew} (how far to the right of the glyph's center +that @code{gtroff} shold place an accent) +of the last glyph added to the current environment. +@endDefreg + @c ===================================================================== -@node Suppressing output, I/O, Environments, gtroff Reference +@node Suppressing output, Colors, Environments, gtroff Reference @section Suppressing output -@cindex suppressing output @Defesc {\\O, , num, } -Disables or enables output depending on the value of @var{num}: +@cindex suppressing output (@code{\O}) +@cindex output, suppressing (@code{\O}) +Disable or enable output depending on the value of @var{num}: @table @samp @item \O0 -Disable any ditroff glyphs from being emitted to the device driver. +Disable any glyphs from being emitted to the device driver, provided that +the escape occurs at the outer level (see @code{\O[3]} and @code{\O[4]}). +Motion is not suppressed so effectively @code{\O[0]} means @emph{pen up}. @item \O1 -Enable output of glyphs. +Enable output of glyphs, provided that the escape occurs at the outer +level. @end table @vindex opminx @@ -8278,25 +11243,148 @@ Enable output of glyphs. @xref{Register Index}. These four registers mark the top left and bottom right hand corners of a box which encompasses all written glyphs. -The following two forms of @code{\O} are specific to @code{grohtml}. +For example the input text: + +@Example +Hello \O[0]world \O[1]this is a test. +@endExample + +@noindent +produces the following output: + +@Example +Hello this is a test. +@endExample @table @samp @item \O2 -Disable any ditroff glyphs from being emitted to the device driver. Also -write out to @code{stderr} the page number and four registers encompassing -the glyphs previously written since the last call to @code{\O}. +Provided that the escape occurs at the outer level, enable output of +glyphs and also write out to @code{stderr} the page number and four +registers encompassing the glyphs previously written since the last call +to @code{\O}. @item \O3 -Enable output of glyphs (the default). Also write out to @code{stderr} -the page number and four registers encompassing the glyphs previously -written since the last call to @code{\O}. +Begin a nesting level. At start-up, @code{gtroff} is at outer level. + +@item \O4 +End a nesting level. + +@item \O[5@var{P}@var{filename}] +This escape is @code{grohtml} specific. Provided that this escape +occurs at the outer nesting level write the @code{filename} to +@code{stderr}. The position of the image, @var{P}, must be specified +and must be one of @code{l}, @code{r}, @code{c}, or@w{ }@code{i} (left, +right, centered, inline). @var{filename} will be associated with the +production of the next inline image. @end table @endDefesc +@c ===================================================================== + +@node Colors, I/O, Suppressing output, gtroff Reference +@section Colors +@cindex colors + +@DefreqList {color, [@Var{n}]} +@DefregListEnd {.color} +If @var{n} is missing or non-zero, activate colors (this is the default); +otherwise, turn it off. + +The read-only number register @code{.color} is@w{ }1 if colors are active, +0@w{ }otherwise. + +Internally, @code{color} sets a global flag; it does not produce a token. +Similar to the @code{cp} request, you should use it at the beginning of +your document to control color output. + +Colors can be also turned off with the @option{-c} command line option. +@endDefreq + +@Defreq {defcolor, ident scheme color_components} +Define color with name @var{ident}. @var{scheme} can be one of the +following values: @code{rgb} (three components), @code{cym} (three +components), @code{cmyk} (four components), and @code{gray} or +@code{grey} (one component). + +@cindex default color +@cindex color, default +Color components can be given either as a hexadecimal string or as +positive decimal integers in the range 0--65535. A hexadecimal string +contains all color components concatenated. It must start with either +@code{#} or @code{##}; the former specifies hex values in the range +0--255 (which are internally multiplied by@w{ }257), the latter in the +range 0--65535. Examples: @code{#FFC0CB} (pink), @code{##ffff0000ffff} +(magenta). The default color name @c{default} can't be redefined; its +value is device-specific (usually black). It is possible that the +default color for @code{\m} and @code{\M} is not identical. + +@cindex @code{f} unit, and colors +@cindex unit, @code{f}, and colors +A new scaling indicator@w{ }@code{f} has been introduced which multiplies +its value by 65536; this makes it convenient to specify color components +as fractions in the range 0 to@w{ }1 (1f equals 65536u). Example: + +@Example +.defcolor darkgreen rgb 0.1f 0.5f 0.2f +@endExample + +Note that @code{f} is the default scaling indicator for the +@code{defcolor} request, thus the above statement is equivalent to + +@Example +.defcolor darkgreen rgb 0.1 0.5 0.2 +@endExample +@endDefreq + +@DefescList {\\m, , c, } +@DefescItem {\\m, @lparen{}, co, } +@DefescListEnd {\\m, @lbrack{}, color, @rbrack} +Set drawing color. The following example shows how to turn the next four +words red. + +@Example +\m[red]these are in red\m[] and these words are in black. +@endExample + +The escape @code{\m[]} returns to the previous color. + +The drawing color is associated with the current environment +(@pxref{Environments}). + +Note that @code{\m} doesn't produce an input token in @code{gtroff}. +As a consequence, it can be used in requests like @code{mc} (which +expects a single character as an argument) to change the color on +the fly: + +@Example +.mc \m[red]x\m[] +@endExample +@endDefesc + +@DefescList {\\M, , c, } +@DefescItem {\\M, @lparen{}, co, } +@DefescListEnd {\\M, @lbrack{}, color, @rbrack} +Set background color for filled objects drawn with the +@code{\D'@dots{}'} commands. + +A red ellipse can be created with the following code: + +@Example +\M[red]\h'0.5i'\D'E 2i 1i'\M[] +@endExample + +The escape @code{\M[]} returns to the previous fill color. + +The fill color is associated with the current environment +(@pxref{Environments}). + +Note that @code{\M} doesn't produce an input token in @code{gtroff}. +@endDefesc + @c ===================================================================== -@node I/O, Postprocessor Access, Suppressing output, gtroff Reference +@node I/O, Postprocessor Access, Colors, gtroff Reference @section I/O @cindex i/o @cindex input and output requests @@ -8305,33 +11393,62 @@ written since the last call to @code{\O}. @code{gtroff} has several requests for including files: -@cindex including a file -@cindex file inclusion @Defreq {so, file} -Reads in the specified @var{file} and +@cindex including a file (@code{so}) +@cindex file, inclusion (@code{so}) +Read in the specified @var{file} and includes it in place of the @code{so} request. This is quite useful for large documents, e.g.@: keeping each chapter in a separate file. @xref{gsoelim}, for more information. + +Since @code{gtroff} replaces the @code{so} request with the contents +of @code{file}, it makes a difference whether the data is terminated with +a newline or not: Assuming that file @file{xxx} contains the word +@samp{foo} without a final newline, this + +@Example +This is +.so xxx +bar +@endExample + +@noindent +yields @samp{This is foobar}. +@endDefreq + +@Defreq {pso, command} +Read the standard output from the specified @var{command} +and includes it in place of the @code{pso} request. + +@cindex safer mode +@cindex mode, safer +@cindex unsafe mode +@cindex mode, unsafe +This request causes an error if used in safer mode (which is the default). +Use @code{groff}'s or @code{troff}'s @option{-U} option to activate unsafe +mode. + +The comment regarding a final newline for the @code{so} request is valid +for @code{pso} also. @endDefreq @Defreq {mso, file} -Identical to the @code{so} request except that @code{gtroff} -searches for the specified -@var{file} in the same directories as macro files for the +Identical to the @code{so} request except that @code{gtroff} searches for +the specified @var{file} in the same directories as macro files for the the @option{-m} command line option. If the file name to be included has the form @file{@var{name}.tmac} and it isn't found, @code{mso} tries to include @file{tmac.@var{name}} and vice versa. @endDefreq -@cindex transparent output -@cindex output, transparent -@Defreq {cf, file} -@Defreqx {trf, file} -Transparently outputs the contents of @var{file}. Each line is output -as it were preceded by @code{\!}; however, the lines are not subject to -copy mode interpretation. If the file does not end with a newline, then -a newline is added. For example, to define a macro@w{ }@code{x} -containing the contents of file@w{ }@file{f}, use +@DefreqList {trf, file} +@DefreqListEnd {cf, file} +@cindex transparent output (@code{cf}, @code{trf}) +@cindex output, transparent (@code{cf}, @code{trf}) +Transparently output the contents of @var{file}. Each line is output +as if it were preceded by @code{\!}; however, the lines are not subject +to copy mode interpretation. If the file does not end with a newline, +then a newline is added (@code{trf} only). For example, to define a +macro@w{ }@code{x} containing the contents of file@w{ }@file{f}, use @Example .di x @@ -8339,38 +11456,65 @@ containing the contents of file@w{ }@file{f}, use .di @endExample -The request @w{@code{.cf @var{filename}}}, when used in a diversion, +Both @code{trf} and @code{cf}, when used in a diversion, embeds an object in the diversion which, when reread, causes the -contents of @var{filename} to be transparently copied through to the -output. - -In @acronym{UNIX} @code{troff}, the contents of @var{filename} +contents of @var{file} to be transparently copied through to the +output. In @acronym{UNIX} @code{troff}, the contents of @var{file} is immediately copied through to the output regardless of whether there is a current diversion; this behaviour is so anomalous that it must be -considered a bug. This request causes a line break. +considered a bug. -@rqindex trf -With @code{trf}, unlike @code{cf}, the file cannot contain characters -such as NUL that are not valid @code{gtroff} input characters -(@pxref{Identifiers}). This request causes a line break. +@cindex @code{trf} request, and invalid characters +@cindex characters, invalid for @code{trf} request +@cindex invalid characters for @code{trf} request +While @code{cf} copies the contents of @var{file} completely unprocessed, +@code{trf} disallows characters such as NUL that are not valid +@code{gtroff} input characters (@pxref{Identifiers}). + +Both requests cause a line break. @endDefreq -@Defreq {nx, } -Forces @code{gtroff} to continue processing of -the file specified as an argument. +@Defreq {nx, [@Var{file}]} +@cindex processing next file (@code{nx}) +@cindex file, processing next (@code{nx}) +@cindex next file, processing (@code{nx}) +Force @code{gtroff} to continue processing of +the file specified as an argument. If no argument is given, immediately +jump to the end of file. @endDefreq -@Defreq {rd, } -The @code{rd} request reads from standard input, and includes what is -read as though it were part of the input file. Text is read until a -blank line is encountered. +@Defreq {rd, [@Var{prompt} [@Var{arg1} @Var{arg2} @dots{}]]} +@cindex reading from standard input (@code{rd}) +@cindex standard input, reading from (@code{rd}) +@cindex input, standard, reading from (@code{rd}) +Read from standard input, and include what is read as though it +were part of the input file. Text is read until a blank line +is encountered. + +If standard input is a TTY input device (keyboard), write @var{prompt} +to standard error, followed by a colon (or send BEL for a beep if no +argument is given). + +Arguments after @var{prompt} are available for the input. For example, +the line + +@Example +.rd data foo bar +@endExample + +with the input @w{@samp{This is \$2.}} prints + +@Example +This is bar. +@endExample @endDefreq @cindex form letters @cindex letters, form Using the @code{nx} and @code{rd} requests, it is easy to set up form letters. The form -letter template is constructed like this: +letter template is constructed like this, putting the following lines +into a file called @file{repeat.let}: @Example .ce @@ -8386,13 +11530,13 @@ Body of letter. .nx repeat.let @endExample -@rqindex ex +@cindex @code{ex} request, used with @code{nx} and @code{rd} @noindent -When this is run, the following file should be redirected in. Note that -requests included in this file are executed as though they were part of -the form letter. The last block of input is the @code{ex} requests -which tells groff to stop processing. If this was not there, groff -would not know when to stop. +When this is run, a file containing the following lines should be +redirected in. Note that requests included in this file are executed +as though they were part of the form letter. The last block of input +is the @code{ex} request which tells @code{groff} to stop processing. If +this was not there, @code{groff} would not know when to stop. @Example Trent A. Fisher @@ -8411,21 +11555,50 @@ Dear Mr. Adollar, @endExample @Defreq {pi, pipe} -Pipes the output of @code{gtroff} to the shell command(s) +Pipe the output of @code{gtroff} to the shell command(s) specified by @var{pipe}. This request must occur before @code{gtroff} has a chance to print anything. + +@cindex safer mode +@cindex mode, safer +@cindex unsafe mode +@cindex mode, unsafe +@code{pi} causes an error if used in safer mode (which is the default). +Use @code{groff}'s or @code{troff}'s @option{-U} option to activate unsafe +mode. + +Multiple calls to @code{pi} are allowed, acting as a chain. For example, + +@Example +.pi foo +.pi bar +... +@endExample + +is the same as @w{@samp{.pi foo | bar}}. + +@cindex @code{groff}, and @code{pi} request +@cindex @code{pi} request, and @code{groff} +Note that the intermediate output format of @code{gtroff} is piped to +the specified commands. Consequently, calling @code{groff} without the +@option{-Z} option normally causes a fatal error. @endDefreq -@Defreq {sy, cmds} -@Defregx {systat} -In @dfn{unsafe} mode, executes the shell command(s) specified by -@var{cmds}. The output is not saved anyplace, so it is up to the user -to do so. +@DefreqList {sy, cmds} +@DefregListEnd {systat} +Execute the shell command(s) specified by @var{cmds}. The output is not +saved anyplace, so it is up to the user to do so. -@c XXX add info about safer and unsafe mode +@cindex safer mode +@cindex mode, safer +@cindex unsafe mode +@cindex mode, unsafe +This request causes an error if used in safer mode (which is the default). +Use @code{groff}'s or @code{troff}'s @option{-U} option to activate unsafe +mode. -For example, the following example introduces the current time -into a document: +For example, the following code fragment introduces the current time into a +document: @cindex time, current @cindex current time @@ -8441,53 +11614,103 @@ into a document: @noindent Note that this works by having the @code{perl} script (run by @code{sy}) print out the @code{nr} requests which set the number registers -@samp{H}, @samp{M} and @samp{S}, and then reads those commands in with +@code{H}, @code{M}, and @code{S}, and then reads those commands in with the @code{so} request. -@cindex @code{system()} return value register +For most practical purposes, the number registers @code{seconds}, +@code{minutes}, and @code{hours} which are initialized at start-up of +@code{gtroff} should be sufficient. Use the @code{af} request to get a +formatted output: + +@Example +.af hours 00 +.af minutes 00 +.af seconds 00 +\n[hours]:\n[minutes]:\n[seconds] +@endExample + +@cindex @code{system()} return value register (@code{systat}) The @code{systat} read-write number register contains the return value of the @code{system()} function executed by the last @code{sy} request. @endDefreq -@Defreq {open, stream file} -@Defreqx {opena, stream file} -Opens the specified @var{file} for writing and +@DefreqList {open, stream file} +@DefreqListEnd {opena, stream file} +@cindex opening file (@code{open}) +@cindex file, opening (@code{open}) +@cindex appending to a file (@code{opena}) +@cindex file, appending to (@code{opena}) +Open the specified @var{file} for writing and associates the specified @var{stream} with it. -The @code{opena} is like @code{open}, but if the file exists, append to -it instead of truncating it. +The @code{opena} request is like @code{open}, but if the file exists, +append to it instead of truncating it. + +@cindex safer mode +@cindex mode, safer +@cindex unsafe mode +@cindex mode, unsafe +Both @code{open} and @code{opena} cause an error if used in safer mode +(which is the default). Use @code{groff}'s or @code{troff}'s @option{-U} +option to activate unsafe mode. @endDefreq +@DefreqList {write, stream data} +@DefreqListEnd {writec, stream data} @cindex copy-in mode, and @code{write} requests @cindex mode, copy-in, and @code{write} requests -@Defreq {write, stream data} -Writes to the file associated with the specified @var{stream}. +@cindex writing to file (@code{write}) +@cindex file, writing to (@code{write}) +Write to the file associated with the specified @var{stream}. The stream must previously have been the subject of an open request. The remainder of the line is interpreted as the @code{ds} request reads its second argument: A leading @samp{"} is stripped, and it is read in copy-in mode. + +The @code{writec} request is like @code{write}, but only +@code{write} appends a newline to the data. +@endDefreq + +@Defreq {writem, stream xx} +@cindex @code{asciify} request, and @code{writem} +Write the contents of the macro or string @var{xx} +to the file associated with the specified @var{stream}. + +@var{xx} is read in copy mode, i.e., already formatted elements are +ignored. Consequently, diversions must be unformatted with the +@code{asciify} request before calling @code{writem}. Usually, this +means a loss of information. @endDefreq @Defreq {close, stream} -Closes the specified @var{stream}; +@cindex closing file (@code{close}) +@cindex file, closing (@code{close}) +Close the specified @var{stream}; the stream is no longer an acceptable argument to the @code{write} request. -@c XXX example +Here a simple macro to write an index entry. -@ignore @Example -... example of open write &c... +.open idx test.idx +. +.de IX +. write idx \\n[%] \\$* +.. +. +.IX test entry +. +.close idx @endExample -@end ignore @endDefreq -@Defesc {\\V, ', xxx, '} -Interpolates the contents of the specified -environment variable, as returned by the function @code{getenv}. -Specify the argument to @code{\V} as an identifier, i.e.@: -@samp{\V@var{x}}, @samp{\V(@var{xx}} or @samp{\V[@var{xxx}]}. @code{\V} -is interpreted in copy-in mode. +@DefescList {\\V, , e, } +@DefescItem {\\V, @lparen{}, ev, } +@DefescListEnd {\\V, @lbrack{}, env, @rbrack} +Interpolate the contents of the specified environment variable +@var{env} (one-character name@w{ }@var{e}, two-character name @var{ev}) +as returned by the function @code{getenv}. @code{\V} is interpreted +in copy-in mode. @endDefesc @@ -8505,18 +11728,44 @@ postprocessor. This is particularly useful for embedding @Defesc {\\X, ', xxx, '} Embeds its argument into the @code{gtroff} output preceded with @w{@samp{x X}}. + +@cindex @code{\&}, in @code{\X} +@cindex @code{\)}, in @code{\X} +@cindex @code{\%}, in @code{\X} +@ifnotinfo +@cindex @code{\:}, in @code{\X} +@end ifnotinfo +@ifinfo +@cindex @code{\@r{<colon>}}, in @code{\X} +@end ifinfo +The escapes @code{\&}, @code{\)}, @code{\%}, and @code{\:} are ignored +within @code{\X}, @w{@samp{\ }} and @code{\~} are converted to single +space characters. All other escapes (except @code{\\} which produces a +backslash) cause an error. + +@kindex use_charnames_in_special +@pindex DESC@r{, and @code{use_charnames_in_special}} +@cindex @code{\X}, and special characters +If the @samp{use_charnames_in_special} keyword is set in the @file{DESC} +file, special characters no longer cause an error; the name @var{xx} is +represented as @samp{\(@var{xx})} in the @w{@samp{x X}} output command. +Additionally, the backslash is represented as @code{\\}. + +@samp{use_charnames_in_special} is currently used by @code{grohtml} only. @endDefesc -@Defesc {\\Y, ', xxx, '} -The @code{\Y} escape is called with an identifier (i.e.@: -@code{\Y@var{x}}, @code{\Y(@var{xx}} or @code{\Y[@var{xxx}]}). This is -approximately equivalent to @samp{\X'\*[@var{xxx}]'}. However, the -contents of the string or macro @var{xxx} are not interpreted; also it -is permitted for @var{xxx} to have been defined as a macro and thus -contain newlines (it is not permitted for the argument to @code{\X} to -contain newlines). The inclusion of newlines requires an extension to -the @acronym{UNIX} @code{troff} output format, and confuses drivers -that do not know about this extension. +@DefescList {\\Y, , n, } +@DefescItem {\\Y, @lparen{}, nm, } +@DefescListEnd {\\Y, @lbrack{}, name, @rbrack} +This is approximately equivalent to @samp{\X'\*[@var{name}]'} +(one-character name@w{ }@var{n}, two-character name @var{nm}). +However, the contents of the string or macro @var{name} are not +interpreted; also it is permitted for @var{name} to have been defined +as a macro and thus contain newlines (it is not permitted for the +argument to @code{\X} to contain newlines). The inclusion of +newlines requires an extension to the @acronym{UNIX} @code{troff} +output format, and confuses drivers that do not know about this +extension (@pxref{Device Control Commands}). @endDefesc @xref{Output Devices}. @@ -8526,50 +11775,105 @@ that do not know about this extension. @node Miscellaneous, Gtroff Internals, Postprocessor Access, gtroff Reference @section Miscellaneous -@cindex miscellaneous This section documents parts of @code{gtroff} which cannot (yet) be categorized elsewhere in this manual. -@cindex line numbers -@cindex numbers, line -@Defreq {nm, start inc space indent} -Prints line numbers in the left margin. +@Defreq {nm, [@Var{start} [@Var{inc} [@Var{space} [@Var{indent}]]]]} +@cindex printing line numbers (@code{nm}) +@cindex line numbers, printing (@code{nm}) +@cindex numbers, line, printing (@code{nm}) +Print line numbers. @var{start} is the line number of the @emph{next} -output line; this defaults to@w{ }1. @var{inc} indicates on -which lines numbers are printed, i.e.@: 5 means put line numbers on -every 5@w{ }lines; this defaults to@w{ }1. @var{space} is the -space to be left between the number and the text; this defaults to@w{ -}1. The fourth argument is the indentation of the line numbers. -Without arguments, line numbers are turned off. -@endDefreq - -@c XXX xref ln register - -@Defreq {nn, [@Var{skip}]} -Temporarily turns off line numbering. The -argument is the number of lines not to be numbered; this defaults -to@w{ }1. - -@c XXX (does this disable incrementing or display?) +output line. @var{inc} indicates which line numbers are printed. +For example, the value@w{ }5 means to emit only line numbers which +are multiples of@w{ }5; this defaults to@w{ }1. @var{space} is the +space to be left between the number and the text; this defaults to +one digit space. The fourth argument is the indentation of the line +numbers, defaulting to zero. Both @var{space} and @var{indent} are +given as multiples of digit spaces; they can be negative also. +Without any arguments, line numbers are turned off. + +@code{gtroff} reserves three digit spaces for the line number (which is +printed right-justified) plus the amount given by @var{indent}; the +output lines are concatenated to the line numbers, separated by +@var{space}, and @emph{without} reducing the line length. Depending +on the value of the horizontal page offset (as set with the +@code{po} request), line numbers which are longer than the reserved +space stick out to the left, or the whole line is moved to the right. + +Parameters corresponding to missing arguments are not changed; any +non-digit argument (to be more precise, any argument starting with a +character valid as a delimiter for identifiers) is also treated as +missing. + +If line numbering has been disabled with a call to @code{nm} without +an argument, it can be reactivated with @samp{.nm +0}, using the +previously active line numbering parameters. + +The parameters of @code{nm} are associated with the current environment +(@pxref{Environments}). The current output line number is available +in the number register @code{ln}. + +@Example +.po 1m +.ll 2i +This test shows how line numbering works with groff. +.nm 999 +This test shows how line numbering works with groff. +.br +.nm xxx 3 2 +.ll -\w'0'u +This test shows how line numbering works with groff. +.nn 2 +This test shows how line numbering works with groff. +@endExample -@c XXX example +@noindent +And here the result: -@ignore @Example -... line numbering example ... + This test shows how + line numbering works + 999 with groff. This +1000 test shows how line +1001 numbering works with +1002 groff. + This test shows how + line numbering + works with groff. + This test shows how +1005 line numbering + works with groff. @endExample -@end ignore @endDefreq -@cindex margin characters -@cindex characters for margins -@Defreq {mc, char dist} -Prints margin characters to the right of the text. -The first argument is the character to be -printed, and the second argument is the distance away from the main body -text. With no arguments the margin characters are turned off. If this -occurs before a break, no margin character is printed. +@Defreq {nn, [@Var{skip}]} +Temporarily turn off line numbering. The argument is the number +of lines not to be numbered; this defaults to@w{ }1. +@endDefreq + +@Defreq {mc, glyph [@Var{dist}]} +@cindex margin glyph (@code{mc}) +@cindex glyph, for margins (@code{mc}) +Print a @dfn{margin character} to the right of the +text.@footnote{@dfn{Margin character} is a misnomer since it is an +output glyph.} The first argument is the glyph to be +printed. The second argument is the distance away from the right +margin. If missing, the previously set value is used; default is +10@dmn{pt}). For text lines that are too long (that is, longer than +the text length plus @var{dist}), the margin character is directly +appended to the lines. + +With no arguments the margin character is turned off. +If this occurs before a break, no margin character is printed. + +@cindex @code{tl} request, and @code{mc} +For empty lines and lines produced by the @code{tl} request no margin +character is emitted. + +The margin character is associated with the current environment +(@pxref{Environments}). @pindex nrchbar @pindex changebar @@ -8578,33 +11882,49 @@ there are programs available for doing this (they are called @code{nrchbar} and @code{changebar} and can be found in any @samp{comp.sources.unix} archive. -@c XXX example - -@ignore @Example -... margin char example ... +.ll 3i +.mc | +This paragraph is highlighted with a margin +character. +.sp +Note that vertical space isn't marked. +.br +\& +.br +But we can fake it with `\&'. @endExample -@end ignore -@endDefreq -@pindex soelim -@cindex multi-file documents -@cindex documents, multi-file -@Defreq {lf, line filename} -A debugging aid for -documents which are split into many files, then put together -with @code{soelim} and other preprocessors. The second argument is the -name of the file and the first argument is the input line number in -that file. This way @code{gtroff} can produce error messages which are -intelligible to the user. - -@c XXX example +Result: -@ignore @Example -... example of soelim'ed doc ... +This paragraph is highlighted | +with a margin character. | + +Note that vertical space isn't | +marked. | + | +But we can fake it with `\&'. | @endExample -@end ignore +@endDefreq + +@DefreqList {psbb, filename} +@DefregItem {llx} +@DefregItem {lly} +@DefregItem {urx} +@DefregListEnd {ury} +@cindex PostScript, bounding box +@cindex bounding box +Retrieve the bounding box of the PostScript image +found in @var{filename}. +The file must conform to +Adobe's @dfn{Document Structuring Conventions} (DSC); +the command searches for a @code{%%BoundingBox} comment +and extracts the bounding box values into the number registers +@code{llx}, @code{lly}, @code{urx}, and @code{ury}. +If an error occurs (for example, @code{psbb} cannot find +the @code{%%BoundingBox} comment), +it sets the four number registers to zero. @endDefreq @@ -8618,20 +11938,29 @@ intelligible to the user. @cindex output node @cindex node, output @code{gtroff} processes input in three steps. One or more input -characters are converted to an @dfn{input token}. Then, one or more -input tokens are converted to an @dfn{output node}. Finally, output -nodes are converted to the intermediate output language understood by -all output devices. - -For example, the input string @samp{fi\[:u]} is converted in a +characters are converted to an @dfn{input token}.@footnote{Except the +escapes @code{\f}, @code{\F}, @code{\H}, @code{\m}, @code{\M}, @code{\R}, +@code{\s}, and @code{\S} which are processed immediately if not in +copy-in mode.} Then, one or more input tokens are converted to an +@dfn{output node}. Finally, output nodes are converted to the +intermediate output language understood by all output devices. + +Actually, before step one happens, @code{gtroff} converts certain +escape sequences into reserved input characters (not accessible by +the user); such reserved characters are used for other internal +processing also -- this is the very reason why not all characters +are valid input. @xref{Identifiers}, for more on this topic. + +For example, the input string @samp{fi\[:u]} is converted into a character token @samp{f}, a character token @samp{i}, and a special token @samp{:u} (representing u@w{ }umlaut). Later on, the character tokens @samp{f} and @samp{i} are merged to a single output node -representing the ligature glyph @samp{fi}; the same happens with -@samp{:u}. All output glyph nodes are `processed' which means that -they are invariably associated with a given font, font size, advance -width, etc. During the formatting process, @code{gtroff} itself adds -various nodes to control the data flow. +representing the ligature glyph @samp{fi} (provided the current font +has a glyph for this ligature); the same happens with @samp{:u}. All +output glyph nodes are `processed' which means that they are invariably +associated with a given font, font size, advance width, etc. During +the formatting process, @code{gtroff} itself adds various nodes to +control the data flow. Macros, diversions, and strings collect elements in two chained lists: a list of input tokens which have been passed unprocessed, and a list @@ -8663,12 +11992,11 @@ It contains these elements. @item --- @tab @code{\n} @tab 9 @end multitable -@esindex \v -@rqindex unformat +@cindex @code{\v}, internal representation @noindent Elements 1, 7, and@w{ }8 are inserted by @code{gtroff}; the latter two (which are always present) specify the vertical extent of the last -line, possibly modified by @code{\v}. The @code{br} request finishes +line, possibly modified by @code{\x}. The @code{br} request finishes the current partial line, inserting a newline input token which is subsequently converted to a space when the diversion is reread. Note that the word space node has a fixed width which isn't stretchable @@ -8678,6 +12006,39 @@ the @code{unformat} request. Macros only contain elements in the token list (and the node list is empty); diversions and strings can contain elements in both lists. +Note that the @code{chop} request simply reduces the number of elements in a +macro, string, or diversion by one. Exceptions are @dfn{compatibility save} +and @dfn{compatibility ignore} input tokens which are ignored. The +@code{substring} request also ignores those input tokens. + +Some requests like @code{tr} or @code{cflags} work on glyph +identifiers only; this means that the associated glyph can be changed +without destroying this association. This can be very helpful for +substituting glyphs. In the following example, we assume that +glyph @samp{foo} isn't available by default, so we provide a +substitution using the @code{fchar} request and map it to input +character @samp{x}. + +@Example +.fchar \[foo] foo +.tr x \[foo] +@endExample + +@noindent +Now let us assume that we install an additional special font +@samp{bar} which has glyph @samp{foo}. + +@Example +.special bar +.rchar \[foo] +@endExample + +@noindent +Since glyphs defined with @code{fchar} are searched before glyphs +in special fonts, we must call @code{rchar} to remove the definition +of the fallback glyph. Anyway, the translation is still active; +@samp{x} now maps to the real glyph @samp{foo}. + @c ===================================================================== @@ -8688,23 +12049,54 @@ empty); diversions and strings can contain elements in both lists. @code{gtroff} is not easy to debug, but there are some useful features and strategies for debugging. -@Defreq {tm, string} -Sends the @var{string} to the standard error stream; -this is very useful for printing debugging output among other things. +@Defreq {lf, line filename} +@pindex soelim +@cindex multi-file documents +@cindex documents, multi-file +@cindex setting input line number (@code{lf}) +@cindex input line number, setting (@code{lf}) +@cindex number, input line, setting (@code{lf}) +Change the line number and the file name @code{gtroff} shall use for +error and warning messages. @var{line} is the input line number of the +@emph{next} line. + +Without argument, the request is ignored. + +This is a debugging aid for documents which are split into many files, +then put together with @code{soelim} and other preprocessors. Usually, +it isn't invoked manually. +@endDefreq + +@DefreqList {tm, string} +@DefreqItem {tm1, string} +@DefreqListEnd {tmc, string} +@cindex printing to stderr (@code{tm}, @code{tm1}, @code{tmc}) +@cindex stderr, printing to (@code{tm}, @code{tm1}, @code{tmc}) +Send @var{string} to the standard error output; +this is very useful for printing debugging messages among other things. + +@var{string} is read in copy mode. + +The @code{tm} request ignores leading spaces of @var{string}; @code{tm1} +handles its argument similar to the @code{ds} request: a leading double +quote in @var{string} is stripped to allow initial blanks. + +The @code{tmc} request is similar to @code{tm1} but does +not append a newline (as is done in @code{tm} and @code{tm1}). @endDefreq -@cindex aborting @Defreq {ab, [@Var{string}]} +@cindex aborting (@code{ab}) Similar to the @code{tm} request, except that it causes @code{gtroff} to stop processing. With no argument it -prints @samp{User Abort}. +prints @samp{User Abort.} to standard error. @endDefreq -@cindex @code{ex}, use in debugging -@cindex exiting @Defreq {ex, } -The @code{ex} request also causes @code{gtroff} to stop processing -if encountered at the topmost level; see also @ref{I/O}. +@cindex @code{ex} request, use in debugging +@cindex exiting (@code{ex}) +The @code{ex} request also causes @code{gtroff} to stop processing; +see also @ref{I/O}. @endDefreq When doing something involved it is useful to leave the debugging @@ -8721,50 +12113,122 @@ To activate these statements say groff -rDB=1 file @endExample -@c XXX .tm1, .tmc requests - If it is known in advance that there will be many errors and no useful output, @code{gtroff} can be forced to suppress formatted output with the @option{-z} flag. -@cindex dumping symbol table -@cindex symbol table, dumping @Defreq {pm, } -The @code{pm} request prints out the entire symbol table on @code{stderr}. +@cindex dumping symbol table (@code{pm}) +@cindex symbol table, dumping (@code{pm}) +Print the entire symbol table on @code{stderr}. Names of all defined +macros, strings, and diversions are print together with their size in +bytes. Since @code{gtroff} sometimes adds nodes by itself, the +returned size can be larger than expected. + +This request differs from @acronym{UNIX} @code{troff}: @code{gtroff} +reports the sizes of diversions, ignores an additional argument to +print only the total of the sizes, and the size isn't returned in +blocks of 128 characters. @endDefreq -@cindex dumping number registers -@cindex number registers, dumping @Defreq {pnr, } -Prints the names and contents of all +@cindex dumping number registers (@code{pnr}) +@cindex number registers, dumping (@code{pnr}) +Print the names and contents of all currently defined number registers on @code{stderr}. @endDefreq -@cindex dumping traps -@cindex traps, dumping @Defreq {ptr, } -Prints the names and positions of all traps +@cindex dumping traps (@code{ptr}) +@cindex traps, dumping (@code{ptr}) +Print the names and positions of all traps (not including input line traps and diversion traps) on @code{stderr}. Empty slots in the page trap list are printed as well, because they can affect the priority of subsequently planted traps. @endDefreq -@cindex flush output -@cindex output, flush +@Defreq {fl, } +@cindex flush output (@code{fl}) +@cindex output, flush (@code{fl}) @cindex interactive use of @code{gtroff} @cindex @code{gtroff}, interactive use -@Defreq {fl, } -Instructs @code{gtroff} to flush its output -immediately. The intent is for interactive use. -@code{gtroff}; there is little other use for it. This -request causes a line break. +Instruct @code{gtroff} to flush its output immediately. The intent +is for interactive use, but this behaviour is currently not +implemented in @code{gtroff}. Contrary to @acronym{UNIX} @code{troff}, +TTY output is sent to a device driver also (@code{grotty}), making it +non-trivial to communicate interactively. + +This request causes a line break. @endDefreq -@cindex backtrace of input stack -@cindex input stack, backtrace @Defreq {backtrace, } -The @code{backtrace} request prints a backtrace of the input stack -to the standard error stream. +@cindex backtrace of input stack (@code{backtrace}) +@cindex input stack, backtrace (@code{backtrace}) +Print a backtrace of the input stack to the standard error stream. + +Consider the following in file @file{test}: + +@Example +.de xxx +. backtrace +.. +.de yyy +. xxx +.. +. +.yyy +@endExample + +@noindent +On execution, @code{gtroff} prints the following: + +@Example +test:2: backtrace: macro `xxx' +test:5: backtrace: macro `yyy' +test:8: backtrace: file `test' +@endExample + +The option @option{-b} of @code{gtroff} internally calls a variant of +this request on each error and warning. +@endDefreq + +@Defreg {slimit} +@cindex input stack, setting limit +Use the @code{slimit} number register +to set the maximum number of objects on the input stack. +If @code{slimit} is less than or equal to@w{ }0, +there is no limit set. +With no limit, a buggy recursive macro can exhaust virtual memory. + +The default value is 1000; this is a compile-time constant. +@endDefreg + +@Defreq {warnscale, si} +Set the scaling indicator used in warnings to @var{si}. Valid values for +@var{si} are @samp{u}, @samp{i}, @samp{c}, @samp{p}, and @samp{P}. At +startup, it is set to @samp{i}. +@endDefreq + +@Defreq {spreadwarn, [@Var{limit}]} +Make @code{gtroff} emit a warning if the additional space inserted for +each space between words in an output line is larger or equal to +@var{limit}. A negative value is changed to zero; no argument toggles the +warning on and off without changing @var{limit}. The default scaling +indicator is @samp{m}. At startup, @code{spreadwarn} is deactivated, and +@var{limit} is set to 3@dmn{m}. + +For example, + +@Example +.spreadwarn 0.2m +@endExample + +@noindent +will cause a warning if @code{gtroff} must add 0.2@dmn{m} or more for each +interword space in a line. + +This request is active only if text is justified to both margins (using +@w{@samp{.ad b}}). @endDefreq @cindex warnings @@ -8772,16 +12236,16 @@ to the standard error stream. (@option{-w}) and for printing backtraces (@option{-b}) when a warning or an error occurs. The most verbose level of warnings is @option{-ww}. -@cindex level of warnings -@cindex warnings, level -@Defreq {warn, [@Var{flags}]} -@Defregx {.warn} -Controls the level of warnings checked for. The @var{flags} are the sum +@DefreqList {warn, [@Var{flags}]} +@DefregListEnd {.warn} +@cindex level of warnings (@code{warn}) +@cindex warnings, level (@code{warn}) +Control the level of warnings checked for. The @var{flags} are the sum of the numbers associated with each warning that is to be enabled; all other warnings are disabled. The number associated with each warning is listed below. For example, @w{@code{.warn 0}} disables all warnings, and @w{@code{.warn 1}} disables all warnings except that about missing -characters. If an argument is not given, all warnings are enabled. +glyphs. If no argument is given, all warnings are enabled. The read-only number register @code{.warn} contains the current warning level. @@ -8805,7 +12269,9 @@ the @option{-w} and @option{-W} options; the number is used by the @table @samp @item char @itemx 1 -Non-existent characters. This is enabled by default. +Non-existent glyphs.@footnote{@code{char} is a misnomer since it reports +missing glyphs -- there aren't missing input characters, only invalid +ones.} This is enabled by default. @item number @itemx 2 @@ -8825,8 +12291,8 @@ Missing or mismatched closing delimiters. @item el @itemx 16 -@rqindex ie -@rqindex el +@cindex @code{ie} request, and warnings +@cindex @code{el} request, and warnings Use of the @code{el} request with no matching @code{ie} request. @xref{if-else}. @@ -8844,55 +12310,61 @@ Dubious syntax in numeric expressions. @item di @itemx 256 -@rqindex di -@rqindex da -@cindex @code{di}, debugging -@cindex @code{da}, debugging +@cindex @code{di} request, and warnings +@cindex @code{da} request, and warnings Use of @code{di} or @code{da} without an argument when there is no current diversion. @item mac @itemx 512 -@rqindex de -@c XXX more index entries +@cindex @code{de}, @code{de1}, @code{dei} requests, and warnings +@cindex @code{am}, @code{am1}, @code{ami} requests, and warnings +@cindex @code{ds}, @code{ds1} requests, and warnings +@cindex @code{as}, @code{as1} requests, and warnings +@cindex @code{di} request, and warnings +@cindex @code{da} request, and warnings +@cindex @code{box}, @code{boxa} requests, and warnings +@cindex @code{\*}, and warnings Use of undefined strings, macros and diversions. When an undefined -string, macro or diversion is used, that string is automatically defined -as empty. So, in most cases, at most one warning is given for each -name. +string, macro, or diversion is used, that string is automatically +defined as empty. So, in most cases, at most one warning is given +for each name. -@item reg +@item reg @itemx 1024 -@rqindex nr -@c XXX more index entries +@cindex @code{nr} request, and warnings +@cindex @code{\R}, and warnings +@cindex @code{\n}, and warnings Use of undefined number registers. When an undefined number register is used, that register is automatically defined to have a value of@w{ }0. -A definition is automatically made with a value of@w{ }0. So, in most -cases, at most one warning is given for use of a particular name. +So, in most cases, at most one warning is given for use of a particular +name. -@item tab +@item tab @itemx 2048 +@cindex @code{\t}, and warnings Use of a tab character where a number was expected. -@item right-brace +@item right-brace @itemx 4096 -@esindex \@} -@cindex @code{\@}}, debugging +@cindex @code{\@}}, and warnings Use of @code{\@}} where a number was expected. -@item missing +@item missing @itemx 8192 Requests that are missing non-optional arguments. -@item input +@item input @itemx 16384 -Illegal input characters. +Invalid input characters. -@item escape +@item escape @itemx 32768 -Unrecognized escape sequences. When an unrecognized escape sequence is -encountered, the escape character is ignored. +Unrecognized escape sequences. When an unrecognized escape sequence +@code{\@var{X}} is encountered, the escape character is ignored, and +@var{X} is printed. -@item space +@item space @itemx 65536 @cindex compatibility mode Missing space between a request or macro and its argument. This warning @@ -8902,10 +12374,19 @@ name. The request or macro is not invoked. When this warning is given, no macro is automatically defined. This is enabled by default. This warning never occurs in compatibility mode. -@item font +@item font @itemx 131072 Non-existent fonts. This is enabled by default. +@item ig +@itemx 262144 +Invalid escapes in text ignored with the @code{ig} request. These are +conditions that are errors when they do not occur in ignored text. + +@item color +@itemx 524288 +Color related warnings. + @item all All warnings except @samp{di}, @samp{mac} and @samp{reg}. It is intended that this covers all warnings that are useful with traditional @@ -8918,11 +12399,11 @@ All warnings. @c ===================================================================== -@node Implementation Differences, Summary, Debugging, gtroff Reference +@node Implementation Differences, , Debugging, gtroff Reference @section Implementation Differences @cindex implementation differences @cindex differences in implementation -@cindex incompatibilities with Unix @code{troff} +@cindex incompatibilities with @acronym{AT&T} @code{troff} @cindex compatibility mode @cindex mode, compatibility @@ -8938,12 +12419,8 @@ interprets .dsabcd @endExample -@esindex \* -@esindex \n -@cindex @code{\*}, incompatibilities with Unix @code{troff} -@cindex @code{\n}, incompatibilities with Unix @code{troff} -@rqindex cp -@vindex .C +@cindex @code{\*}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\n}, incompatibilities with @acronym{AT&T} @code{troff} @noindent as defining a string @samp{ab} with contents @samp{cd}. Normally, GNU @code{troff} interprets this as a call of a macro named @@ -8953,25 +12430,83 @@ called @samp{[}. In GNU @code{troff}, however, this is normally interpreted as the start of a long name. In compatibility mode GNU @code{troff} interprets long names in the traditional way (which means that they are not recognized as names). -Compatibility mode can be turned on with the @option{-C} command line -option, and turned on or off with the @code{cp} request. The number -register @code{.C} is@w{ }1 if compatibility mode is on, 0@w{ -}otherwise. - -@esindex \A -@esindex \| -@esindex \^ -@esindex \& -@esindex \@{ -@esindex \@} -@esindex \@key{SP} -@esindex \' -@esindex \` -@esindex \- -@esindex \_ -@esindex \! -@esindex \% -@esindex \c + +@DefreqList {cp, [@Var{n}]} +@DefreqItem {do, cmd} +@DefregListEnd {.C} +If @var{n} is missing or non-zero, turn on compatibility mode; +otherwise, turn it off. + +The read-only number register @code{.C} is@w{ }1 if compatibility mode is +on, 0@w{ }otherwise. + +Compatibility mode can be also turned on with the @option{-C} command line +option. + +The @code{do} request turns off compatibility mode +while executing its arguments as a @code{gtroff} command. + +@Example +.do fam T +@endExample + +@noindent +executes the @code{fam} request when compatibility mode +is enabled. + +@code{gtroff} restores the previous compatibility setting +before interpreting any files sourced by the @var{cmd}. +@endDefreq + +@cindex input level in delimited arguments +@cindex delimited arguments, incompatibilities with @acronym{AT&T} @code{troff} +Two other features are controlled by @option{-C}. If not in +compatibility mode, GNU @code{troff} preserves the input level in +delimited arguments: + +@Example +.ds xx ' +\w'abc\*(xxdef' +@endExample + +@noindent +In compatibility mode, the string @samp{72def'} is returned; without +@option{-C} the resulting string is @samp{168} (assuming a TTY output +device). + +@cindex @code{\f}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\H}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\s}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\S}, incompatibilities with @acronym{AT&T} @code{troff} +Finally, the escapes @code{\f}, @code{\H}, @code{\m}, @code{\M}, +@code{\R}, @code{\s}, and @code{\S} are transparent for recognizing the +beginning of a line only in compatibility mode (this is a rather obscure +feature). For example, the code + +@Example +.de xx +Hallo! +.. +\fB.xx\fP +@endExample + +prints @samp{Hallo!} in bold face if in compatibility mode, and +@samp{.xx} in bold face otherwise. + +@cindex @code{\A}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\|}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\^}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\&}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\@{}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\@}}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\@key{SP}}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\'}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\`}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\-}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\_}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\!}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\%}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\c}, incompatibilities with @acronym{AT&T} @code{troff} GNU @code{troff} does not allow the use of the escape sequences @code{\|}, @code{\^}, @code{\&}, @code{\@{}, @code{\@}}, @code{\@key{SP}}, @code{\'}, @code{\`}, @code{\-}, @code{\_}, @code{\!}, @@ -8981,9 +12516,11 @@ registers, fonts or environments; @acronym{UNIX} @code{troff} does. The avoiding use of these escape sequences in names. @cindex fractional point sizes +@cindex fractional type sizes @cindex point sizes, fractional -@rqindex ps -@cindex @code{ps}, incompatibilities with Unix @code{troff} +@cindex type sizes, fractional +@cindex sizes, fractional +@cindex @code{ps} request, incompatibilities with @acronym{AT&T} @code{troff} Fractional point sizes cause one noteworthy incompatibility. In @acronym{UNIX} @code{troff} the @code{ps} request ignores scale indicators and thus @@ -8997,30 +12534,25 @@ sets the point size to 10@w{ }points, whereas in GNU @code{troff} it sets the point size to 10@w{ }scaled points. @xref{Fractional Type Sizes}, for more information. -@rqindex bd -@rqindex cs -@rqindex tkf -@rqindex tr -@rqindex fp -@cindex @code{bd}, incompatibilities with Unix @code{troff} -@cindex @code{cs}, incompatibilities with Unix @code{troff} -@cindex @code{tkf}, incompatibilities with Unix @code{troff} -@cindex @code{tr}, incompatibilities with Unix @code{troff} -@cindex @code{fp}, incompatibilities with Unix @code{troff} -@cindex input and output characters, compatibility with Unix -@cindex output characters, compatibility with Unix -@cindex characters, input and output, compatibility with Unix +@cindex @code{bd} request, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{cs} request, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{tr} request, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{fp} request, incompatibilities with @acronym{AT&T} @code{troff} +@cindex input characters and output glyphs, compatibility with @acronym{AT&T} @code{troff} +@cindex output glyphs, and input characters,compatibility with @acronym{AT&T} @code{troff} +@cindex characters, input, and output glyphs, compatibility with @acronym{AT&T} @code{troff} +@cindex glyphs, output, and input characters, compatibility with @acronym{AT&T} @code{troff} In GNU @code{troff} there is a fundamental difference between -unformatted, input characters, and formatted, output characters. -Everything that affects how an output character is output is stored -with the character; once an output character has been constructed it is +(unformatted) input characters and (formatted) output glyphs. +Everything that affects how a glyph is output is stored +with the glyph node; once a glyph node has been constructed it is unaffected by any subsequent requests that are executed, including @code{bd}, @code{cs}, @code{tkf}, @code{tr}, or @code{fp} requests. -Normally output characters are constructed from input characters at the -moment immediately before the character is added to the current output +Normally glyphs are constructed from input characters at the +moment immediately before the glyph is added to the current output line. Macros, diversions and strings are all, in fact, the same type of -object; they contain lists of input characters and output characters in -any combination. An output character does not behave like an input +object; they contain lists of input characters and glyph nodes in +any combination. A glyph node does not behave like an input character for the purposes of macro processing; it does not inherit any of the special properties that the input character from which it was constructed might have had. For example, @@ -9033,14 +12565,13 @@ constructed might have had. For example, .x @endExample -@esindex \e -@esindex \! -@esindex \? -@cindex @code{\e}, incompatibilities with Unix @code{troff} -@cindex @code{\!}, incompatibilities with Unix @code{troff} -@cindex @code{\?}, incompatibilities with Unix @code{troff} -@cindex transparent output, incompatibilities with Unix @code{troff} -@cindex output, transparent, incompatibilities with Unix @code{troff} +@cindex printing backslash (@code{\\}, @code{\e}, @code{\E}, @code{\[rs]}) +@cindex backslash, printing (@code{\\}, @code{\e}, @code{\E}, @code{\[rs]}) +@cindex @code{\e}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\!}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex @code{\?}, incompatibilities with @acronym{AT&T} @code{troff} +@cindex transparent output, incompatibilities with @acronym{AT&T} @code{troff} +@cindex output, transparent, incompatibilities with @acronym{AT&T} @code{troff} @noindent prints @samp{\\} in GNU @code{troff}; each pair of input backslashes is turned into one output backslash and the resulting output backslashes @@ -9051,24 +12582,14 @@ correct way to obtain a printable backslash is to use the @code{\e} escape sequence: This always prints a single instance of the current escape character, regardless of whether or not it is used in a diversion; it also works in both GNU @code{troff} and @acronym{UNIX} -@code{troff}. To store, for some reason, an escape sequence in a +@code{troff}.@footnote{To be completely independent of the current +escape character, use @code{\(rs} which represents a reverse solidus +(backslash) glyph.} To store, for some reason, an escape sequence in a diversion that will be interpreted when the diversion is reread, either use the traditional @code{\!} transparent output facility, or, if this is unsuitable, the new @code{\?} escape sequence. -@c XXX .tl compatibility mode -> input stack level -@c XXX .if compatibility mode -> input stack level - -@xref{Diversions}, for more information. - - -@c ===================================================================== - -@node Summary, , Implementation Differences, gtroff Reference -@section Summary -@cindex summary - -@c XXX documentation +@xref{Diversions}, and @ref{Gtroff Internals}, for more information. @@ -9097,8 +12618,8 @@ which are freely available. @node geqn, gtbl, Preprocessors, Preprocessors @section @code{geqn} -@cindex @code{eqn} -@cindex @code{geqn} +@cindex @code{eqn}, the program +@cindex @code{geqn}, the program @c XXX @@ -9120,8 +12641,8 @@ which are freely available. @node gtbl, gpic, geqn, Preprocessors @section @code{gtbl} -@cindex @code{tbl} -@cindex @code{gtbl} +@cindex @code{tbl}, the program +@cindex @code{gtbl}, the program @c XXX @@ -9143,8 +12664,8 @@ which are freely available. @node gpic, ggrn, gtbl, Preprocessors @section @code{gpic} -@cindex @code{pic} -@cindex @code{gpic} +@cindex @code{pic}, the program +@cindex @code{gpic}, the program @c XXX @@ -9166,8 +12687,8 @@ which are freely available. @node ggrn, grap, gpic, Preprocessors @section @code{ggrn} -@cindex @code{grn} -@cindex @code{ggrn} +@cindex @code{grn}, the program +@cindex @code{ggrn}, the program @c XXX @@ -9189,7 +12710,7 @@ which are freely available. @node grap, grefer, ggrn, Preprocessors @section @code{grap} -@cindex @code{grap} +@cindex @code{grap}, the program A free implementation of @code{grap}, written by Ted Faber, is available as an extra package from the following address: @@ -9203,8 +12724,8 @@ is available as an extra package from the following address: @node grefer, gsoelim, grap, Preprocessors @section @code{grefer} -@cindex @code{refer} -@cindex @code{grefer} +@cindex @code{refer}, the program +@cindex @code{grefer}, the program @c XXX @@ -9226,8 +12747,8 @@ is available as an extra package from the following address: @node gsoelim, , grefer, Preprocessors @section @code{gsoelim} -@cindex @code{soelim} -@cindex @code{gsoelim} +@cindex @code{soelim}, the program +@cindex @code{gsoelim}, the program @c XXX @@ -9284,7 +12805,7 @@ is available as an extra package from the following address: @node grotty, grops, Special Characters, Output Devices @section @code{grotty} -@cindex @code{grotty} +@cindex @code{grotty}, the program @c XXX @@ -9301,12 +12822,29 @@ is available as an extra package from the following address: @c XXX +@c The following is no longer true; fix and extend it. + +@c @pindex less +@c @cindex Teletype +@c @cindex ISO 6249 SGR +@c @cindex terminal control sequences +@c @cindex control sequences, for terminals +@c For TTY output devices, underlining is done by emitting sequences of +@c @samp{_} and @samp{\b} (the backspace character) before the actual +@c character. Literally, this is printing an underline character, then +@c moving back one character position, and printing the actual character +@c at the same position as the underline character (similar to a +@c typewriter). Usually, a modern terminal can't interpret this (and the +@c original Teletype machines for which this sequence was appropriate are +@c no longer in use). You need a pager program like @code{less} which +@c translates this into ISO 6429 SGR sequences to control terminals. + @c ===================================================================== @node grops, grodvi, grotty, Output Devices @section @code{grops} -@cindex @code{grops} +@cindex @code{grops}, the program @c XXX @@ -9328,8 +12866,8 @@ is available as an extra package from the following address: @node Embedding PostScript, , Invoking grops, grops @subsection Embedding @sc{PostScript} -@cindex embedding postscript -@cindex postscript, embedding +@cindex embedding PostScript +@cindex PostScript, embedding @c XXX @@ -9338,7 +12876,7 @@ is available as an extra package from the following address: @node grodvi, grolj4, grops, Output Devices @section @code{grodvi} -@cindex @code{grodvi} +@cindex @code{grodvi}, the program @c XXX @@ -9360,7 +12898,7 @@ is available as an extra package from the following address: @node grolj4, grolbp, grodvi, Output Devices @section @code{grolj4} -@cindex @code{grolj4} +@cindex @code{grolj4}, the program @c XXX @@ -9382,7 +12920,7 @@ is available as an extra package from the following address: @node grolbp, grohtml, grolj4, Output Devices @section @code{grolbp} -@cindex @code{grolbp} +@cindex @code{grolbp}, the program @c XXX @@ -9404,29 +12942,64 @@ is available as an extra package from the following address: @node grohtml, gxditview, grolbp, Output Devices @section @code{grohtml} -@cindex @code{grohtml} +@cindex @code{grohtml}, the program @c XXX @menu * Invoking grohtml:: +* grohtml specific registers and strings:: @end menu @c --------------------------------------------------------------------- -@node Invoking grohtml, , grohtml, grohtml +@node Invoking grohtml, grohtml specific registers and strings, grohtml, grohtml @subsection Invoking @code{grohtml} @cindex invoking @code{grohtml} @cindex @code{grohtml}, invoking @c XXX +@c --------------------------------------------------------------------- + +@node grohtml specific registers and strings, , Invoking grohtml, grohtml +@subsection @code{grohtml} specific registers and strings +@cindex registers specific to @code{grohtml} +@cindex strings specific to @code{grohtml} +@cindex @code{grohtml}, registers and strings + +@DefmpregList {ps4html, grohtml} +@DefstrListEnd {www-image-template, grohtml} +The registers @code{ps4html} and @code{www-image-template} are defined +by the @code{pre-grohtml} preprocessor. @code{pre-grohtml} reads in +the @code{troff} input, marks up the inline equations and passes the +result firstly to + +@Example +troff -Tps -rps4html=1 -dwww-image-template=@var{template} +@endExample + +@noindent +and secondly to + +@Example +troff -Thtml +@endExample + +The PostScript device is used to create all the image files, and the +register @code{ps4html} enables the macro sets to ignore floating +keeps, footers, and headings. + +The register @code{www-image-template} is set to the user specified +template name or the default name. +@endDefmpreg + @c ===================================================================== @node gxditview, , grohtml, Output Devices @section @code{gxditview} -@cindex @code{gxditview} +@cindex @code{gxditview}, the program @c XXX @@ -9454,7 +13027,8 @@ is available as an extra package from the following address: @cindex file formats @cindex formats, file -@c XXX +All files read and written by @code{gtroff} are text files. The +following two sections describe their format. @menu * gtroff Output:: @@ -9466,280 +13040,887 @@ is available as an extra package from the following address: @node gtroff Output, Font Files, File formats, File formats @section @code{gtroff} Output -@cindex @code{gtroff} output +@cindex @code{gtroff}, output @cindex output, @code{gtroff} -This section describes the format output of GNU @code{troff}. The -output format used by GNU @code{troff} is very similar -- but -not identical -- to that used by -@acronym{UNIX} device-independent @code{troff} (@code{ditroff}). +This section describes the intermediate output format of GNU +@code{troff}. This output is produced by a run of @code{gtroff} +before it is fed into a device postprocessor program. + +As @code{groff} is a wrapper program around @code{gtroff} that +automatically calls a postprocessor, this output does not show up +normally. This is why it is called @dfn{intermediate}. +@code{groff} provides the option @option{-Z} to inhibit postprocessing, +such that the produced intermediate output is sent to standard output +just like calling @code{gtroff} manually. + +@cindex troff output +@cindex output, troff +@cindex intermediate output +@cindex output, intermediate +Here, the term @dfn{troff output} describes what is output by +@code{gtroff}, while @dfn{intermediate output} refers to the language +that is accepted by the parser that prepares this output for the +postprocessors. This parser is smarter on whitespace and implements +obsolete elements for compatibility, otherwise both formats are the +same.@footnote{The parser and postprocessor for intermediate output +can be found in the file@* +@file{@var{groff-source-dir}/src/libs/libdriver/input.cc}.} + +The main purpose of the intermediate output concept is to facilitate +the development of postprocessors by providing a common programming +interface for all devices. It has a language of its own that is +completely different from the @code{gtroff} language. While the +@code{gtroff} language is a high-level programming language for text +processing, the intermediate output language is a kind of low-level +assembler language by specifying all positions on the page for writing +and drawing. + +The intermediate output produced by @code{gtroff} is fairly readable, +while output from @acronym{AT&T} @code{troff} is rather hard to +understand because of strange habits that are still supported, but not +used any longer by @code{gtroff}. @menu -* Output Format:: -* Device Control:: -* Drawing Functions:: -* Line Continuation:: +* Language Concepts:: +* Command Reference:: +* Intermediate Output Examples:: +* Output Language Compatibility:: @end menu @c --------------------------------------------------------------------- -@node Output Format, Device Control, gtroff Output, gtroff Output -@subsection Output Format -@cindex output format -@cindex format of output +@node Language Concepts, Command Reference, gtroff Output, gtroff Output +@subsection Language Concepts -@cindex 8-bit input -@cindex input, 8-bit -The output format is text based, as opposed to a binary format (like -@TeX{} DVI). The output format is @w{8-bit} clean, thus single -characters can have the eighth bit set, as can the names of fonts and -special characters. +During the run of @code{gtroff}, the input data is cracked down to the +information on what has to be printed at what position on the intended +device. So the language of the intermediate output format can be quite +small. Its only elements are commands with and without arguments. +In this section, the term @dfn{command} always refers to the intermediate +output language, and never to the @code{gtroff} language used for document +formatting. There are commands for positioning and text writing, for drawing, and +for device controlling. -The output format consists of single command characters with attached -parameters which are separated from subsequent text by whitespace or a -newline. +@menu +* Separation:: +* Argument Units:: +* Document Parts:: +@end menu -The names of characters and fonts can be of arbitrary length; drivers -should not assume that they are only two characters long (as -@code{ditroff} does). +@node Separation, Argument Units, Language Concepts, Language Concepts +@subsubsection Separation + +@acronym{AT&T} @code{troff} output has strange requirements on whitespace. +The @code{gtroff} output parser, however, is smart about whitespace by +making it maximally optional. The whitespace characters, i.e., the +tab, space, and newline characters, always have a syntactical meaning. +They are never printable because spacing within the output is always +done by positioning commands. + +Any sequence of space or tab characters is treated as a single +@dfn{syntactical space}. It separates commands and arguments, but is +only required when there would occur a clashing between the command code +and the arguments without the space. Most often, this happens when +variable-length command names, arguments, argument lists, or command +clusters meet. Commands and arguments with a known, fixed length need +not be separated by syntactical space. + +A line break is a syntactical element, too. Every command argument can be +followed by whitespace, a comment, or a newline character. Thus a +@dfn{syntactical line break} is defined to consist of optional +syntactical space that is optionally followed by a comment, and a +newline character. + +The normal commands, those for positioning and text, consist of a +single letter taking a fixed number of arguments. For historical reasons, +the parser allows to stack such commands on the same line, but +fortunately, in @code{gtroff}'s intermediate output, every command with +at least one argument is followed by a line break, thus providing +excellent readability. + +The other commands -- those for drawing and device controlling -- +have a more complicated structure; some recognize long command names, +and some take a variable number of arguments. So all @samp{D} and +@samp{x} commands were designed to request a syntactical line break +after their last argument. Only one command, @w{@samp{x X}}, +has an argument that can stretch over several lines; all other +commands must have all of their arguments on the same line as the +command, i.e., the arguments may not be splitted by a line break. + +Empty lines (these are lines containing only space and/or a comment), can +occur everywhere. They are just ignored. + +@node Argument Units, Document Parts, Separation, Language Concepts +@subsubsection Argument Units + +Some commands take integer arguments that are assumed to represent +values in a measurement unit, but the letter for the corresponding +scale indicator is not written with the output command arguments. +Most commands assume the scale indicator @samp{u}, the basic unit of +the device, some use @samp{z}, the scaled point unit of the device, +while others, such as the color commands, expect plain integers. + +Note that single characters can have the eighth bit set, as can the +names of fonts and special characters. The names of characters and +fonts can be of arbitrary length. A character that is to be printed +will always be in the current font. + +A string argument is always terminated by the next whitespace +character (space, tab, or newline); an embedded @samp{#} character is +regarded as part of the argument, not as the beginning of a comment +command. An integer argument is already terminated by the next +non-digit character, which then is regarded as the first character of +the next argument or command. + +@node Document Parts, , Argument Units, Language Concepts +@subsubsection Document Parts + +A correct intermediate output document consists of two parts, the +@dfn{prologue} and the @dfn{body}. + +The task of the prologue is to set the general device parameters +using three exactly specified commands. @code{gtroff}'s prologue +is guaranteed to consist of the following three lines (in that order): + +@Example +x T @var{device} +x res @var{n} @var{h} @var{v} +x init +@endExample -When a character is to be printed, that character is always in the -current font. Unlike @code{ditroff}, it is not necessary for drivers to -search special fonts to find a character. +@noindent +with the arguments set as outlined in @ref{Device Control Commands}. +Note that the parser for the intermediate output format is able to +swallow additional whitespace and comments as well even in the +prologue. + +The body is the main section for processing the document data. +Syntactically, it is a sequence of any commands different from the +ones used in the prologue. Processing is terminated as soon as the +first @w{@samp{x stop}} command is encountered; the last line of any +@code{gtroff} intermediate output always contains such a command. + +Semantically, the body is page oriented. A new page is started by a +@samp{p} command. Positioning, writing, and drawing commands are +always done within the current page, so they cannot occur before the +first @samp{p} command. Absolute positioning (by the @samp{H} and +@samp{V} commands) is done relative to the current page; all other +positioning is done relative to the current location within this page. -@table @code -@item H@var{n} -@c XXX +@c --------------------------------------------------------------------- -@item V@var{n} -@c XXX +@node Command Reference, Intermediate Output Examples, Language Concepts, gtroff Output +@subsection Command Reference -@item h@var{n} -@c XXX +This section describes all intermediate output commands, both from +@acronym{AT&T} @code{troff} as well as the @code{gtroff} extensions. -@item v@var{n} -@c XXX +@menu +* Comment Command:: +* Simple Commands:: +* Graphics Commands:: +* Device Control Commands:: +* Obsolete Command:: +@end menu -@item c@var{n} -@c XXX +@node Comment Command, Simple Commands, Command Reference, Command Reference +@subsubsection Comment Command -@item C@var{n} -@c XXX +@table @code +@item #@var{anything}@angles{end of line} +A comment. Ignore any characters from the @samp{#} character up to +the next newline character. -@item @var{nn}@var{c} -@c XXX +This command is the only possibility for commenting in the intermediate +output. Each comment can be preceded by arbitrary syntactical space; +every command can be terminated by a comment. +@end table -@item t@var{xxx} -@var{xxx} is any sequence of characters terminated by a space or a -newline; the first character should be printed at the current position, -the the current horizontal position should be increased by the width of -the first character, and so on for each character. The width of the -character is that given in the font file, appropriately scaled for the -current point size, and rounded so that it is a multiple of the -horizontal resolution. Special characters cannot be printed using this -command. +@node Simple Commands, Graphics Commands, Comment Command, Command Reference +@subsubsection Simple Commands -@kindex tcommand -@pindex DESC@r{, and @code{tcommand}} -This command is only allowed if the @samp{tcommand} line is present in -the @file{DESC} file. +The commands in this subsection have a command code consisting of a +single character, taking a fixed number of arguments. Most of them +are commands for positioning and text writing. These commands are +smart about whitespace. Optionally, syntactical space can be inserted +before, after, and between the command letter and its arguments. +All of these commands are stackable, i.e., they can be preceded by +other simple commands or followed by arbitrary other commands on the +same line. A separating syntactical space is only necessary when two +integer arguments would clash or if the preceding argument ends with a +string argument. + +@table @code +@ignore +.if (\n[@USE_ENV_STACK] == 1) \{\ +.command { +Open a new environment by copying the actual device configuration data +to the environment stack. +. +The current environment is setup by the device specification and +manipulated by the setting commands. +. +. +.command } +Close the actual environment (opened by a preceding +.BR { \~command) +and restore the previous environment from the environment +stack as the actual device configuration data. +. +\} \" endif @USE_ENV_STACK +@end ignore -@item u@var{n} @var{xxx} -This is same as the @samp{t} command except that after printing each -character, the current horizontal position is increased by the sum of -the width of that character and@w{ }@var{n}. +@item C @var{xxx}@angles{whitespace} +Print a special character named @var{xxx}. The trailing +syntactical space or line break is necessary to allow glyph names +of arbitrary length. The glyph is printed at the current print +position; the glyph's size is read from the font file. The print +position is not changed. + +@item c @var{g} +Print glyph@w{ }@var{g} at the current print position;@footnote{@samp{c} +is actually a misnomer since it outputs a glyph.} the glyph's size is +read from the font file. The print position is not changed. + +@item f @var{n} +Set font to font number@w{ }@var{n} (a non-negative integer). + +@item H @var{n} +Move right to the absolute vertical position@w{ }@var{n} (a +non-negative integer in basic units @samp{u} relative to left edge +of current page. + +@item h @var{n} +Move @var{n} (a non-negative integer) basic units @samp{u} horizontally +to the right. The original @acronym{UNIX} troff manual allows negative +values for @var{n} also, but @code{gtroff} doesn't use this. + +@item m @var{color-scheme} @r{[}@var{component} @dots{}@r{]} +Set the color for text (glyphs), line drawing, and the outline of +graphic objects using different color schemes; the analoguous command +for the filling color of graphic objects is @samp{DF}. The color +components are specified as integer arguments between 0 and 65536. +The number of color components and their meaning vary for the +different color schemes. These commands are generated by +@code{gtroff}'s escape sequence @code{\m}. No position changing. +These commands are a @code{gtroff} extension. -This command is only allowed if the @samp{tcommand} line is present in -the @file{DESC} file. +@table @code +@item mc @var{cyan} @var{magenta} @var{yellow} +Set color using the CMY color scheme, having the 3@w{ }color components +@var{cyan}, @var{magenta}, and @var{yellow}. -@item n@var{a}@var{b} -@c XXX +@item md +Set color to the default color value (black in most cases). +No component arguments. -@item p@var{n} -@c XXX +@item mg @var{gray} +Set color to the shade of gray given by the argument, an integer +between 0 (black) and 65536 (white). -@item s@var{n} -@kindex sizescale -@pindex DESC@r{, and @code{sizescale}} -The argument to the @samp{s} command is in scaled points (units of -points/@var{n}, where @var{n} is the argument to the @samp{sizescale} -command in the @file{DESC} file). +@item mk @var{cyan} @var{magenta} @var{yellow} @var{black} +Set color using the CMYK color scheme, having the 4@w{ }color components +@var{cyan}, @var{magenta}, @var{yellow}, and @var{black}. -@item f@var{n} -@item x @dots{} \n -Device control. -@c XXX more info +@item mr @var{red} @var{green} @var{blue} +Set color using the RGB color scheme, having the 3@w{ }color components +@var{red}, @var{green}, and @var{blue}. -@item D@var{c} @var{x}@dots{}\n -@c XXX @end table -@c --------------------------------------------------------------------- +@item N @var{n} +Print glyph with index@w{ }@var{n} (a non-negative integer) of the +current font. This command is a @code{gtroff} extension. + +@item n @var{b} @var{a} +Inform the device about a line break, but no positioning is done by +this command. In @acronym{AT&T} @code{troff}, the integer arguments +@var{b} and@w{ }@var{a} informed about the space before and after the +current line to make the intermediate output more human readable +without performing any action. In @code{groff}, they are just ignored, but +they must be provided for compatibility reasons. + +@item p @var{n} +Begin a new page in the outprint. The page number is set +to@w{ }@var{n}. This page is completely independent of pages formerly +processed even if those have the same page number. The vertical +position on the outprint is automatically set to@w{ }0. All +positioning, writing, and drawing is always done relative to a page, +so a @samp{p} command must be issued before any of these commands. + +@item s @var{n} +Set point size to @var{n}@w{ }scaled points (this is unit @samp{z}). +@acronym{AT&T} @code{troff} used the unit points (@samp{p}) instead. +@xref{Output Language Compatibility}. + +@item t @var{xxx}@angles{whitespace} +@itemx t @var{xxx} @var{dummy-arg}@angles{whitespace} +Print a word, i.e., a sequence of characters @var{xxx} representing +output glyphs which names are single characters, terminated by +a space character or a line break; an optional second integer argument +is ignored (this allows the formatter to generate an even number of +arguments). The first glyph should be printed at the current +position, the current horizontal position should then be increased by +the width of the first glyph, and so on for each glyph. +The widths of the glyphs are read from the font file, scaled for the +current point size, and rounded to a multiple of the horizontal +resolution. Special characters cannot be printed using this command +(use the @samp{C} command for special characters). This command is a +@code{gtroff} extension; it is only used for devices whose @file{DESC} +file contains the @code{tcommand} keyword (@pxref{DESC File Format}). + +@item u @var{n} @var{xxx}@angles{whitespace} +Print word with track kerning. This is the same as the @samp{t} +command except that after printing each glyph, the current +horizontal position is increased by the sum of the width of that +glyph and@w{ }@var{n} (an integer in basic units @samp{u}). +This command is a @code{gtroff} extension; it is only used for devices +whose @file{DESC} file contains the @code{tcommand} keyword +(@pxref{DESC File Format}). + +@item V @var{n} +Move down to the absolute vertical position@w{ }@var{n} (a +non-negative integer in basic units @samp{u}) relative to upper edge +of current page. + +@item v @var{n} +Move @var{n}@w{ }basic units @samp{u} down (@var{n} is a non-negative +integer). The original @acronym{UNIX} troff manual allows negative +values for @var{n} also, but @code{gtroff} doesn't use this. -@node Device Control, Drawing Functions, Output Format, gtroff Output -@subsection Device Control -@cindex device control -@cindex control of devices +@item w +Informs about a paddable white space to increase readability. +The spacing itself must be performed explicitly by a move command. -The @samp{x} command is normally followed by a letter or word indicating -the function to perform, followed by white space separated arguments. +@end table -The first argument can be abbreviated to the first letter. +@node Graphics Commands, Device Control Commands, Simple Commands, Command Reference +@subsubsection Graphics Commands + +Each graphics or drawing command in the intermediate output starts +with the letter @samp{D}, followed by one or two characters that +specify a subcommand; this is followed by a fixed or variable number +of integer arguments that are separated by a single space character. +A @samp{D} command may not be followed by another command on the same line +(apart from a comment), so each @samp{D} command is terminated by a +syntactical line break. + +@code{gtroff} output follows the classical spacing rules (no space +between command and subcommand, all arguments are preceded by a +single space character), but the parser allows optional space between +the command letters and makes the space before the first argument +optional. As usual, each space can be any sequence of tab and space +characters. + +Some graphics commands can take a variable number of arguments. +In this case, they are integers representing a size measured in basic +units @samp{u}. The arguments called @var{h1}, @var{h2}, @dots{}, +@var{hn} stand for horizontal distances where positive means right, +negative left. The arguments called @var{v1}, @var{v2}, @dots{}, +@var{vn} stand for vertical distances where positive means down, +negative up. All these distances are offsets relative to the current +location. + +Unless indicated otherwise, each graphics command directly corresponds +to a similar @code{gtroff} @code{\D} escape sequence. @xref{Drawing +Requests}. + +Unknown @samp{D} commands are assumed to be device-specific. +Its arguments are parsed as strings; the whole information is then +sent to the postprocessor. + +In the following command reference, the syntax element +@angles{line break} means a syntactical line break as defined above. @table @code -@item x init -@c XXX +@item D~ @var{h1} @var{v1} @var{h2} @var{v2} @dots{} @var{hn} @var{vn}@angles{line break} +Draw B-spline from current position to offset (@var{h1},@var{v1}), +then to offset (@var{h2},@var{v2}), if given, etc.@: up to +(@var{hn},@var{vn}). This command takes a variable number of argument +pairs; the current position is moved to the terminal point of the drawn +curve. + +@item Da @var{h1} @var{v1} @var{h2} @var{v2}@angles{line break} +Draw arc from current position to +(@var{h1},@var{v1})@math{+}(@var{h2},@var{v2}) with center at +(@var{h1},@var{v1}); then move the current position to the final point +of the arc. + +@item DC @var{d}@angles{line break} +@itemx DC @var{d} @var{dummy-arg}@angles{line break} +Draw a solid circle using the current fill color with +diameter@w{ }@var{d} (integer in basic units @samp{u}) with leftmost +point at the current position; then move the current position to the +rightmost point of the circle. An optional second integer argument is +ignored (this allows the formatter to generate an even number of +arguments). This command is a @code{gtroff} extension. + +@item Dc @var{d}@angles{line break} +Draw circle line with diameter@w{ }@var{d} (integer in basic units +@samp{u}) with leftmost point at the current position; then move the +current position to the rightmost point of the circle. + +@item DE @var{h} @var{v}@angles{line break} +Draw a solid ellipse in the current fill color with a horizontal +diameter of@w{ }@var{h} and a vertical diameter of@w{ }@var{v} (both +integers in basic units @samp{u}) with the leftmost point at the +current position; then move to the rightmost point of the ellipse. +This command is a @code{gtroff} extension. + +@item De @var{h} @var{v}@angles{line break} +Draw an outlined ellipse with a horizontal diameter of@w{ }@var{h} +and a vertical diameter of@w{ }@var{v} (both integers in basic units +@samp{u}) with the leftmost point at current position; then move to +the rightmost point of the ellipse. + +@item DF @var{color-scheme} @r{[}@var{component} @dots{}@r{]}@angles{line break} +Set fill color for solid drawing objects using different color +schemes; the analoguous command for setting the color of text, line +graphics, and the outline of graphic objects is @samp{m}. +The color components are specified as integer arguments between 0 and +65536. The number of color components and their meaning vary for the +different color schemes. These commands are generated by @code{gtroff}'s +escape sequences @w{@code{\D'F @dots{}'}} and @code{\M} (with no other +corresponding graphics commands). No position changing. This command +is a @code{gtroff} extension. -@item x T -@c XXX +@table @code +@item DFc @var{cyan} @var{magenta} @var{yellow}@angles{line break} +Set fill color for solid drawing objects using the CMY color scheme, +having the 3@w{ }color components @var{cyan}, @var{magenta}, and +@var{yellow}. -@item x res @var{n} @var{h} @var{v} -@c XXX +@item DFd@angles{line break} +Set fill color for solid drawing objects to the default fill color value +(black in most cases). No component arguments. + +@item DFg @var{gray}@angles{line break} +Set fill color for solid drawing objects to the shade of gray given by +the argument, an integer between 0 (black) and 65536 (white). + +@item DFk @var{cyan} @var{magenta} @var{yellow} @var{black}@angles{line break} +Set fill color for solid drawing objects using the CMYK color scheme, +having the 4@w{ }color components @var{cyan}, @var{magenta}, @var{yellow}, +and @var{black}. + +@item DFr @var{red} @var{green} @var{blue}@angles{line break} +Set fill color for solid drawing objects using the RGB color scheme, +having the 3@w{ }color components @var{red}, @var{green}, and @var{blue}. -@item x H -@c XXX more info -The argument to the @w{@samp{x Height}} command is also in scaled -points. @end table -The first three output commands are guaranteed to be: +@item Df @var{n}@angles{line break} +The argument@w{ }@var{n} must be an integer in the range @math{-32767} +to 32767. -@Example -x T device -x res n h v -x init -@endExample +@table @asis +@item @math{0 @LE @var{n} @LE 1000} +Set the color for filling solid drawing objects to a shade of gray, +where 0 corresponds to solid white, 1000 (the default) to solid black, +and values in between to intermediate shades of gray; this is +obsoleted by command @samp{DFg}. -@noindent -For example, the input +@item @math{@var{n} @LT 0} or @math{@var{n} @LT 1000} +Set the filling color to the color that is currently being used for +the text and the outline, see command @samp{m}. For example, the +command sequence @Example -crunchy \fH\s+2frog\s0\fP!? +mg 0 0 65536 +Df -1 @endExample @noindent -produces +sets all colors to blue. -@c XXX example +@end table +@noindent +No position changing. This command is a @code{gtroff} extension. + +@item Dl @var{h} @var{v}@angles{line break} +Draw line from current position to offset (@var{h},@var{v}) (integers +in basic units @samp{u}); then set current position to the end of the +drawn line. + +@item Dp @var{h1} @var{v1} @var{h2} @var{v2} @dots{} @var{hn} @var{vn}@angles{line break} +Draw a polygon line from current position to offset (@var{h1},@var{v1}), +from there to offset (@var{h2},@var{v2}), etc.@: up to offset +(@var{hn},@var{vn}), and from there back to the starting position. +For historical reasons, the position is changed by adding the sum of +all arguments with odd index to the actual horizontal position and the +even ones to the vertical position. Although this doesn't make sense +it is kept for compatibility. @ignore -@Example -... sample output here ... -@endExample +As the polygon is closed, the end of drawing is the starting point, so +the position doesn't change. @end ignore +This command is a @code{gtroff} extension. -@c --------------------------------------------------------------------- +@item Dp @var{h1} @var{v1} @var{h2} @var{v2} @dots{} @var{hn} @var{vn}@angles{line break} +Draw a solid polygon in the current fill color rather than an outlined +polygon, using the same arguments and positioning as the corresponding +@samp{Dp} command. +@ignore +No position changing. +@end ignore +This command is a @code{gtroff} extension. + +@item Dt @var{n}@angles{line break} +Set the current line thickness to@w{ }@var{n} (an integer in basic +units @samp{u}) if @math{@var{n}>0}; if @math{@var{n}=0} select the +smallest available line thickness; if @math{@var{n}<0} set the line +thickness proportional to the point size (this is the default before +the first @samp{Dt} command was specified). For historical reasons, +the horizontal position is changed by adding the argument to the actual +horizontal position, while the vertical position is not changed. +Although this doesn't make sense it is kept for compatibility. +@ignore +No position changing. +@end ignore +This command is a @code{gtroff} extension. -@node Drawing Functions, Line Continuation, Device Control, gtroff Output -@subsection Drawing Functions -@cindex drawing functions -@cindex functions for drawing +@end table -@pindex gpic -The @samp{D} drawing command has been extended. These extensions are -used by GNU @code{pic} only if the @option{-x} option is given. +@node Device Control Commands, Obsolete Command, Graphics Commands, Command Reference +@subsubsection Device Control Commands + +Each device control command starts with the letter @samp{x}, +followed by a space character (optional or arbitrary space or tab in +@code{gtroff}) and a subcommand letter or word; each argument (if any) +must be preceded by a syntactical space. All @samp{x} commands are +terminated by a syntactical line break; no device control command can +be followed by another command on the same line (except a comment). + +The subcommand is basically a single letter, but to increase +readability, it can be written as a word, i.e., an arbitrary sequence +of characters terminated by the next tab, space, or newline character. +All characters of the subcommand word but the first are simply ignored. +For example, @code{gtroff} outputs the initialization command +@w{@samp{x i}} as @w{@samp{x init}} and the resolution command +@w{@samp{x r}} as @w{@samp{x res}}. -@xref{Drawing Requests}. +In the following, the syntax element @angles{line break} means a +syntactical line break (@pxref{Separation}). @table @code -@c XXX ... -@item Df @var{n} -Set the shade of gray to be used for filling solid objects to@w{ -}@var{n}; @var{n}@w{ }must be an integer between 0 and@w{ }1000, where 0 -corresponds solid white and 1000 to solid black, and values in between -correspond to intermediate shades of gray. This applies only to solid -circles, solid ellipses and solid polygons. By default, a level of@w{ -}1000 is used. Whatever color a solid object has, it should -completely obscure everything beneath it. A value greater than@w{ }1000 -or less than@w{ }0 can also be used: this means fill with the shade of -gray that is currently being used for lines and text. Normally this -is black, but some drivers may provide a way of changing this. - -@item DC @var{d} -Draw a solid circle with a diameter of@w{ }@var{d} with the leftmost -point at the current position. - -@item DE @var{dx} @var{dy} -Draw a solid ellipse with a horizontal diameter of@w{ }@var{dx} and a -vertical diameter of@w{ }@var{dy} with the leftmost point at the current -position. +@item xF @var{name}@angles{line break} +The @samp{F} stands for @var{Filename}. + +Use @var{name} as the intended name for the current file in error +reports. This is useful for remembering the original file name when +@code{gtroff} uses an internal piping mechanism. The input file is +not changed by this command. This command is a @code{gtroff} extension. + +@item xf @var{n} @var{s}@angles{line break} +The @samp{f} stands for @var{font}. + +Mount font position@w{ }@var{n} (a non-negative integer) with font +named@w{ }@var{s} (a text word). @xref{Font Positions}. + +@item xH @var{n}@angles{line break} +The @samp{H} stands for @var{Height}. + +Set glyph height to@w{ }@var{n} (a positive integer in scaled +points @samp{z}). @acronym{AT&T} @code{troff} uses the unit points +(@samp{p}) instead. @xref{Output Language Compatibility}. + +@item xi@angles{line break} +The @samp{i} stands for @var{init}. + +Initialize device. This is the third command of the prologue. + +@item xp@angles{line break} +The @samp{p} stands for @var{pause}. + +Parsed but ignored. The original @acronym{UNIX} troff manual writes + +@display +pause device, can be restarted +@end display + +@item xr @var{n} @var{h} @var{v}@angles{line break} +The @samp{r} stands for @var{resolution}. + +Resolution is@w{ }@var{n}, while @var{h} is the minimal horizontal +motion, and @var{v} the minimal vertical motion possible with this +device; all arguments are positive integers in basic units @samp{u} +per inch. This is the second command of the prologue. + +@item xS @var{n}@angles{line break} +The @samp{S} stands for @var{Slant}. + +Set slant to@w{ }@var{n} (an integer in basic units @samp{u}). + +@item xs@angles{line break} +The @samp{s} stands for @var{stop}. + +Terminates the processing of the current file; issued as the last +command of any intermediate troff output. + +@item xt@angles{line break} +The @samp{t} stands for @var{trailer}. + +Generate trailer information, if any. In @var{gtroff}, this is +actually just ignored. + +@item xT @var{xxx}@angles{line break} +The @samp{T} stands for @var{Typesetter}. + +Set name of device to word @var{xxx}, a sequence of characters ended +by the next white space character. The possible device names coincide +with those from the @code{groff} @option{-T} option. This is the first +command of the prologue. + +@item xu @var{n}@angles{line break} +The @samp{u} stands for @var{underline}. + +Configure underlining of spaces. If @var{n} is@w{ }1, start +underlining of spaces; if @var{n} is@w{ }0, stop underlining of spaces. +This is needed for the @code{cu} request in nroff mode and is ignored +otherwise. This command is a @code{gtroff} extension. + +@item xX @var{anything}@angles{line break} +The @samp{x} stands for @var{X-escape}. + +Send string @var{anything} uninterpreted to the device. If the line +following this command starts with a @samp{+} character this line is +interpreted as a continuation line in the following sense. The +@samp{+} is ignored, but a newline character is sent instead to the +device, the rest of the line is sent uninterpreted. The same applies +to all following lines until the first character of a line is not a +@samp{+} character. This command is generated by the @code{gtroff} +escape sequence @code{\X}. The line-continuing feature is a +@code{gtroff} extension. -@item Dp @var{dx1} @var{dy1} @var{dx2} @var{dy2} @dots{} @var{dxn} @var{dyn} -Draw a polygon with automatic closure. The first vertex is at the -current position, the second vertex at an offset (@var{dx1},@var{dy1}) -from the current position, the second vertex at an offset -(@var{dx2},@var{dy2}) from the first vertex, and so on up to the -@var{n}@dmn{th} vertex. At the moment, GNU @code{pic} only uses this -command to generate triangles and rectangles. - -@item DP @var{dx1} @var{dy1} @var{dx2} @var{dy2} @dots{} @var{dxn} @var{dyn} -Like @code{Dp} but draw a solid rather than outlined polygon. - -@item Dt @var{n} -@cindex line thickness -@cindex thickness of lines -Set the current line thickness to @var{n}@w{ }machine units. -Traditionally, @acronym{UNIX} @code{troff} drivers use a line thickness -proportional to the current point size; drivers should continue to do -this if no @code{Dt} command has been given, or if a @code{Dt} command -has been given with a negative value of@w{ }@var{n}. A zero value of@w{ -}@var{n} selects the smallest available line thickness. @end table -@esindex \D -A difficulty arises in how the current position should be changed after -the execution of these commands. This is not of great importance since -the code generated by GNU @code{pic} does not depend on this. Given a -drawing command of the form +@node Obsolete Command, , Device Control Commands, Command Reference +@subsubsection Obsolete Command +In @acronym{AT&T} @code{troff} output, the writing of a single +glyph is mostly done by a very strange command that combines a +horizontal move and a single character giving the glyph name. It +doesn't have a command code, but is represented by a 3-character +argument consisting of exactly 2@w{ }digits and a character. -@Example -\D'@var{c} @var{x1} @var{y1} @var{x2} @var{y2} @dots{} @var{xn} @var{yn}' -@endExample +@table @asis +@item @var{dd}@var{g} +Move right @var{dd} (exactly two decimal digits) basic units @samp{u}, +then print glyph@w{ }@var{g} (represented as a single character). + +In @code{gtroff}, arbitrary syntactical space around and within this +command is allowed to be added. Only when a preceding command on the +same line ends with an argument of variable length a separating space +is obligatory. In @acronym{AT&T} @code{troff}, large clusters of these +and other commands are used, mostly without spaces; this made such output +almost unreadable. + +@end table + +For modern high-resolution devices, this command does not make sense +because the width of the glyphs can become much larger than two +decimal digits. In @code{gtroff}, this is only used for the devices +@code{X75}, @code{X75-12}, @code{X100}, and @code{X100-12}. For other +devices, the commands @samp{t} and @samp{u} provide a better +functionality. + +@c --------------------------------------------------------------------- + +@node Intermediate Output Examples, Output Language Compatibility, Command Reference, gtroff Output +@subsection Intermediate Output Examples + +This section presents the intermediate output generated from the same +input for three different devices. The input is the sentence +@samp{hell world} fed into @code{gtroff} on the command line. + +@table @asis +@item High-resolution device @code{ps} + +This is the standard output of @code{gtroff} if no @option{-T} option +is given. + +@example +@group +shell> echo "hell world" | groff -Z -T ps + +x T ps +x res 72000 1 1 +x init +@end group +p1 +x font 5 TR +f5 +s10000 +V12000 +H72000 +thell +wh2500 +tw +H96620 +torld +n12000 0 +@group +x trailer +V792000 +x stop +@end group +@end example -@esindex \w -@vindex st -@vindex sb @noindent -where @var{c} is not one of @samp{c}, @samp{e}, @samp{l}, @samp{a} or -@samp{~}, @acronym{UNIX} @code{troff} treats each x@w{ }value -as a horizontal quantity, and each y@w{ }value as a vertical -quantity; it assumes that the width of the drawn object is the sum of -all x@w{ }values, and that the height is the sum of all y@w{ }values. -(The assumption about the height can be seen by examining the @code{st} -and @code{sb} registers after using such a @code{D}@w{ }command in a -@code{\w} escape sequence.) This rule also holds for all the original -drawing commands with the exception of @code{De}. For the sake of -compatibility GNU @code{troff} also follows this rule, even though it -produces an ugly result in the case of the @code{Df}, @code{Dt}, and, to -a lesser extent, @code{DE}@w{ }commands. Thus after executing a -@code{D}@w{ }command of the form +This output can be fed into @code{grops} to get its representation as +a PostScript file. -@Example -D@var{c} @var{x1} @var{y1} @var{x2} @var{y2} @dots{} @var{xn} @var{yn} -@endExample +@item Low-resolution device @code{latin1} + +This is similar to the high-resolution device except that the +positioning is done at a minor scale. Some comments (lines starting +with @samp{#}) were added for clarification; they were not generated +by the formatter. + +@example +@group +shell> echo "hell world" | groff -Z -T latin1 + +# prologue +x T latin1 +x res 240 24 40 +x init +@end group +# begin a new page +p1 +# font setup +x font 1 R +f1 +s10 +# initial positioning on the page +V40 +H0 +# write text `hell' +thell +# inform about space, and issue a horizontal jump +wh24 +# write text `world' +tworld +# announce line break, but do nothing because ... +n40 0 +@group +# ... the end of the document has been reached +x trailer +V2640 +x stop +@end group +@end example @noindent -the current position should be increased horizontally by the sum of all -x@w{ }values and vertically by the sum of all y@w{ }values. +This output can be fed into @code{grotty} to get a formatted text +document. + +@item @acronym{AT&T} @code{troff} output +Since a computer monitor has a very low resolution compared to modern +printers the intermediate output for the X@w{ }Window devices can use +the jump-and-write command with its 2-digit displacements. + +@example +@group +shell> echo "hell world" | groff -Z -T X100 + +x T X100 +x res 100 1 1 +x init +@end group +p1 +x font 5 TR +f5 +s10 +V16 +H100 +# write text with jump-and-write commands +ch07e07l03lw06w11o07r05l03dh7 +n16 0 +@group +x trailer +V1100 +x stop +@end group +@end example + +@noindent +This output can be fed into @code{xditview} or @code{gxditview} +for displaying in@w{ }X. + +Due to the obsolete jump-and-write command, the text clusters in the +@acronym{AT&T} @code{troff} output are almost unreadable. + +@end table @c --------------------------------------------------------------------- -@node Line Continuation, , Drawing Functions, gtroff Output -@subsection Line Continuation -@cindex line continuation in output commands -@cindex output commands, line continuation +@node Output Language Compatibility, , Intermediate Output Examples, gtroff Output +@subsection Output Language Compatibility -There is a continuation convention which permits the argument to the -@w{@samp{x X}} command to contain newlines: When outputting the argument -to the @w{@samp{x X}} command, GNU @code{troff} follows each newline -in the argument with a @samp{+} character (as usual, it terminates -the entire argument with a newline); thus if the line after the line -containing the @w{@samp{x X}} command starts with @samp{+}, then the -newline ending the line containing the @w{@samp{x X}} command should be -treated as part of the argument to the @w{@samp{x X}} command, the -@samp{+} should be ignored, and the part of the line following the -@samp{+} should be treated like the part of the line following the -@w{@samp{x X}} command. +The intermediate output language of @acronym{AT&T} @code{troff} +was first documented in the @acronym{UNIX} troff manual, with later +additions documented in @cite{A Typesetter-indenpendent TROFF}, +written by Brian Kernighan. + +The @code{gtroff} intermediate output format is compatible with this +specification except for the following features. + +@itemize @bullet +@item +The classical quasi device independence is not yet implemented. + +@item +The old hardware was very different from what we use today. So the +@code{groff} devices are also fundamentally different from the ones in +@acronym{AT&T} @code{troff}. For example, the @acronym{AT&T} +PostScript device is called @code{post} and has a resolution of only +720 units per inch, suitable for printers 20 years ago, while +@code{groff}'s @code{ps} device has a resolution of +72000 units per inch. Maybe, by implementing some rescaling +mechanism similar to the classical quasi device independence, +@code{groff} could emulate @acronym{AT&T}'s @code{post} device. + +@item +The B-spline command @samp{D~} is correctly handled by the +intermediate output parser, but the drawing routines aren't +implemented in some of the postprocessor programs. + +@item +The argument of the commands @samp{s} and @w{@samp{x H}} has the +implicit unit scaled point @samp{z} in @code{gtroff}, while +@acronym{AT&T} @code{troff} has point (@samp{p}). This isn't an +incompatibility but a compatible extension, for both units coincide +for all devices without a @code{sizescale} parameter in the @file{DESC} +file, including all postprocessors from @acronym{AT&T} and +@code{groff}'s text devices. The few @code{groff} devices with +a @code{sizescale} parameter either do not exist for @acronym{AT&T} +@code{troff}, have a different name, or seem to have a different +resolution. So conflicts are very unlikely. + +@item +The position changing after the commands @samp{Dp}, @samp{DP}, and +@samp{Dt} is illogical, but as old versions of @code{gtroff} used this +feature it is kept for compatibility reasons. + +@ignore +Temporarily, there existed some confusion on the positioning after the +@samp{D} commands that are groff extensions. This has been clarified +by establishing the classical rule for all @code{groff} drawing commands: + +@itemize +@item +The position after a graphic object has been drawn is at its end; +for circles and ellipses, the `end' is at the right side. + +@item +From this, the positionings specified for the drawing commands above +follow quite naturally. +@end itemize +@end ignore + +@end itemize @c ===================================================================== @@ -9750,9 +13931,11 @@ treated as part of the argument to the @w{@samp{x X}} command, the @cindex files, font The @code{gtroff} font format is roughly a superset of the -@code{ditroff} font format. Unlike the @code{ditroff} font format, -there is no associated binary format; all files are text files. The -font files for device @var{name} are stored in a directory +@code{ditroff} font format (as used in later versions of @acronym{AT&T} +@code{troff} and its descendants). Unlike the @code{ditroff} font +format, there is no associated binary format; all files are text +files.@footnote{Plan@w{ }9 @code{troff} has also abandoned the binary +format.} The font files for device @var{name} are stored in a directory @file{dev@var{name}}. There are two types of file: a device description file called @file{DESC} and for each font@w{ }@var{f} a font file called@w{ }@file{@var{f}}. @@ -9766,25 +13949,27 @@ called@w{ }@file{@var{f}}. @node DESC File Format, Font File Format, Font Files, Font Files @subsection @file{DESC} File Format -@cindex @file{DESC} file format -@cindex font description file format +@cindex @file{DESC} file, format +@cindex font description file, format @cindex format of font description file @pindex DESC@r{ file format} -The @file{DESC} file can contain the following types of line: +The @file{DESC} file can contain the following types of line. Except +for the @code{charset} keyword which must comes last (if at all), the +order of the lines is not important. @table @code @item res @var{n} @kindex res -There are @var{n} machine units per inch. +There are @var{n}@w{ }machine units per inch. @item hor @var{n} @kindex hor -The horizontal resolution is @var{n} machine units. +The horizontal resolution is @var{n}@w{ }machine units. @item vert @var{n} @kindex vert -The vertical resolution is @var{n} machine units. +The vertical resolution is @var{n}@w{ }machine units. @item sizescale @var{n} @kindex sizescale @@ -9798,17 +13983,34 @@ One scaled point is equal to one point/@var{n}. The arguments to the Quantities in the font files are given in machine units for fonts whose point size is @var{n}@w{ }scaled points. +@item prepro @var{program} +@kindex prepro +Call @var{program} as a preprocessor. Currently, this keyword is used +by @code{groff} with option @option{-Thtml} only. + +@item postpro @var{program} +@kindex postpro +Call @var{program} as a postprocessor. For example, the line + +@Example +postpro grodvi +@endExample + +@noindent +in the file @file{devdvi/DESC} makes @code{groff} call @code{grodvi} +if option @option{-Tdvi} is given (and @option{-Z} isn't used). + @item tcommand @kindex tcommand This means that the postprocessor can handle the @samp{t} and @samp{u} -output commands. +intermediate output commands. @item sizes @var{s1} @var{s2} @dots{} @var{sn} 0 @kindex sizes This means that the device has fonts at @var{s1}, @var{s2}, @dots{} -@var{sn} scaled points. The list of sizes must be terminated by a@w{ -}0. Each @var{si} can also be a range of sizes @var{m}-@var{n}. The -list can extend over more than one line. +@var{sn} scaled points. The list of sizes must be terminated by@w{ }0 +(this is digit zero). Each @var{si} can also be a range of sizes +@var{m}-@var{n}. The list can extend over more than one line. @item styles @var{S1} @var{S2} @dots{} @var{Sm} @kindex styles @@ -9820,36 +14022,84 @@ The first @var{m}@w{ }font positions are associated with styles Fonts @var{F1} @dots{} @var{Fn} are mounted in the font positions @var{m}+1, @dots{}, @var{m}+@var{n} where @var{m} is the number of styles. This command may extend over more than one line. A font name -of@var{ }0 means no font is mounted on the corresponding font position. +of@w{ }0 means no font is mounted on the corresponding font position. @item family @var{fam} @kindex family The default font family is @var{fam}. +@item use_charnames_in_special +@kindex use_charnames_in_special +This command indicates that @code{gtroff} should encode special +characters inside special commands. Currently, this is only used +by the @acronym{HTML} output device. @xref{Postprocessor Access}. + +@item papersize @var{string} @dots{} +@kindex papersize +Select a paper size. Valid values for @var{string} are the ISO paper +types @code{A0}-@code{A7}, @code{B0}-@code{B7}, @code{C0}-@code{C7}, +@code{D0}-@code{D7}, @code{DL}, and the US paper types @code{letter}, +@code{legal}, @code{tabloid}, @code{ledger}, @code{statement}, +@code{executive}, @code{com10}, and @code{monarch}. Case is not significant +for @var{string} if it holds predefined paper types. Alternatively, +@var{string} can be a file name (e.g.@: @file{/etc/papersize}); if the file +can be opened, @code{groff} reads the first line and tests for the above +paper sizes. Finally, @var{string} can be a custom paper size in the format +@code{@var{length},@var{width}} (no spaces before and after the comma). +Both @var{length} and @var{width} must have a unit appended; valid values +are @samp{i} for inches, @samp{C} for centimeters, @samp{p} for points, and +@samp{P} for picas. Example: @code{12c,235p}. An argument which starts +with a digit is always treated as a custom paper format. @code{papersize} +sets both the vertical and horizontal dimension of the output medium. + +More than one argument can be specified; @code{groff} scans from left to +right and uses the first valid paper specification. + +@item pass_filenames +@kindex pass_filenames +Tell @code{gtroff} to emit the name of the source file currently +being processed. This is achieved by the intermediate output command +@samp{F}. Currently, this is only used by the @acronym{HTML} output +device. + +@item print @var{program} +@kindex print +Use @var{program} as a spooler program for printing. If omitted, +the @option{-l} and @option{-L} options of @code{groff} are ignored. + @item charset @kindex charset This line and everything following in the file are ignored. It is allowed for the sake of backwards compatibility. @end table -The @code{res}, @code{unitwidth}, @code{fonts} and @code{sizes} lines +The @code{res}, @code{unitwidth}, @code{fonts}, and @code{sizes} lines are mandatory. Other commands are ignored by @code{gtroff} but may be used by postprocessors to store arbitrary information about the device in the @file{DESC} file. -@c XXX add other commands resp. xrefs to output devices -@c XXX add obsolete commands +@kindex spare1 +@kindex spare2 +@kindex biggestfont +Here a list of obsolete keywords which are recognized by @code{groff} +but completely ignored: @code{spare1}, @code{spare2}, +@code{biggestfont}. + @c --------------------------------------------------------------------- @node Font File Format, , DESC File Format, Font Files @subsection Font File Format -@cindex font file format +@cindex font file, format +@cindex font description file, format @cindex format of font files +@cindex format of font description files -A font file has two sections. The first section is a sequence of lines -each containing a sequence of blank delimited words; the first word in -the line is a key, and subsequent words give a value for that key. +A @dfn{font file}, also (and probably better) called a @dfn{font +description file}, has two sections. The first section is a sequence +of lines each containing a sequence of blank delimited words; the first +word in the line is a key, and subsequent words give a value for that +key. @table @code @item name @var{f} @@ -9862,21 +14112,22 @@ The normal width of a space is@w{ }@var{n}. @item slant @var{n} @kindex slant -The characters of the font have a slant of @var{n}@w{ }degrees. +The glyphs of the font have a slant of @var{n}@w{ }degrees. (Positive means forward.) @item ligatures @var{lig1} @var{lig2} @dots{} @var{lign} [0] @kindex ligatures -Characters @var{lig1}, @var{lig2}, @dots{}, @var{lign} are ligatures; +Glyphs @var{lig1}, @var{lig2}, @dots{}, @var{lign} are ligatures; possible ligatures are @samp{ff}, @samp{fi}, @samp{fl}, @samp{ffi} and @samp{ffl}. For backwards compatibility, the list of ligatures may be terminated with a@w{ }0. The list of ligatures may not extend over more than one line. @item special +@cindex special fonts @kindex special -The font is special; this means that when a character is requested that -is not present in the current font, it is searched for in any +The font is @dfn{special}; this means that when a glyph is requested +that is not present in the current font, it is searched for in any special fonts that are mounted. @end table @@ -9896,68 +14147,94 @@ subsection. These subsections can appear in any order. Each subsection starts with a word on a line by itself. @kindex charset -The word @code{charset} starts the character set subsection. The -@code{charset} line is followed by a sequence of lines. Each line gives -information for one character. A line comprises a number of fields -separated by blanks or tabs. The format is +The word @code{charset} starts the character set +subsection.@footnote{This keyword is misnamed since it starts a list +of ordered glyphs, not characters.} The @code{charset} line is +followed by a sequence of lines. Each line gives information for one +glyph. A line comprises a number of fields separated by blanks or +tabs. The format is -@c XXX fix it for new HTML additions - -@Example -@var{name} @var{metrics} @var{type} @var{code} @var{comment} -@endExample +@quotation +@var{name} @var{metrics} @var{type} @var{code} +[@var{entity-name}] [@code{--} @var{comment}] +@end quotation @cindex 8-bit input @cindex input, 8-bit -@esindex \N +@cindex accessing unnamed glyphs with @code{\N} +@cindex unnamed glyphs, accessing with @code{\N} +@cindex characters, unnamed, accessing with @code{\N} +@cindex glyphs, unnamed, accessing with @code{\N} @kindex --- @noindent -@var{name} identifies the character: If @var{name} is a single -character@w{ }@var{c} then it corresponds to the @code{gtroff} input -character @var{c}; if it is of the form @samp{\@var{c}} where @var{c} is -a single character, then it corresponds to the @code{gtroff} input -character@w{ }\@var{c}; otherwise it corresponds to the groff input -character @samp{\[@var{name}]}. (If it is exactly two characters -@var{xx} it can be entered as @samp{\(@var{xx}}.) @code{gtroff} -supports 8-bit characters; however some utilities have difficulties with -eight-bit characters. For this reason, there is a convention that the -name @samp{char@var{n}} is equivalent to the single character whose code -is@w{ }@var{n}. For example, @samp{char163} would be equivalent to the -character with code@w{ }163 which is the pounds sterling sign in @w{ISO -Latin-1} character set. The name @samp{---} is special and indicates -that the character is unnamed; such characters can only be used by means -of the @code{\N} escape sequence in @code{gtroff}. - -@c XXX input encodings vs. output encodings - -The @var{type} field gives the character type: +@var{name} identifies the glyph name@footnote{The distinction between +input, characters, and output, glyphs, is not clearly separated in the +terminology of @code{groff}; for example, the @code{char} request +should be called @code{glyph} since it defines an output entity.}: +If @var{name} is a single character@w{ }@var{c} then it corresponds +to the @code{gtroff} input character@w{ }@var{c}; if it is of the form +@samp{\@var{c}} where @var{c} is a single character, then it +corresponds to the special character @code{\[@var{c}]}; otherwise it +corresponds to the special character @samp{\[@var{name}]}. If it +is exactly two characters @var{xx} it can be entered as +@samp{\(@var{xx}}. Note that single-letter special characters can't +be accessed as @samp{\@var{c}}; the only exception is @samp{\-} which +is identical to @code{\[-]}. + +@code{gtroff} supports 8-bit input characters; however some utilities +have difficulties with eight-bit characters. For this reason, there is +a convention that the entity name @samp{char@var{n}} is equivalent to +the single input character whose code is@w{ }@var{n}. For example, +@samp{char163} would be equivalent to the character with code@w{ }163 +which is the pounds sterling sign in the @w{ISO Latin-1} character set. +You shouldn't use @samp{char@var{n}} entities in font description files +since they are related to input, not output. Otherwise, you get +hard-coded connections between input and output encoding which +prevents use of different (input) character sets. + +The name @samp{---} is special and indicates that the glyph is +unnamed; such glyphs can only be used by means of the @code{\N} +escape sequence in @code{gtroff}. + +The @var{type} field gives the glyph type: @table @code @item 1 -the character has an descender, for example, `p'; +the glyph has a descender, for example, @samp{p}; @item 2 -the character has an ascender, for example, `b'; +the glyph has an ascender, for example, @samp{b}; @item 3 -the character has both an ascender and a descender, for example, `('. +the glyph has both an ascender and a descender, for example, @samp{(}. @end table The @var{code} field gives the code which the postprocessor uses to -print the character. The character can also be input to @code{gtroff} -using this code by means of the @code{\N} escape sequence. The code can -be any integer. If it starts with @samp{0} it is interpreted as +print the glyph. The glyph can also be input to @code{gtroff} +using this code by means of the @code{\N} escape sequence. @var{code} +can be any integer. If it starts with @samp{0} it is interpreted as octal; if it starts with @samp{0x} or @samp{0X} it is interpreted as -hexadecimal. +hexadecimal. Note, however, that the @code{\N} escape sequence only +accepts a decimal integer. -Anything on the line after the @var{code} field is ignored. +The @var{entity-name} field gives an @acronym{ASCII} string +identifying the glyph which the postprocessor uses to print the +@code{gtroff} glyph @var{name}. This field is optional and has been +introduced so that the @acronym{HTML} device driver can encode its +character set. For example, the glyph @samp{\[Po]} is +represented as @samp{£} in @acronym{HTML} 4.0. + +Anything on the line after the @var{entity-name} field resp.@: after +@samp{--} will be ignored. The @var{metrics} field has the form: -@Example -@var{width}[,@var{height}[,@var{depth}[,@var{italic_correction} - [,@var{left_italic_correction}[,@var{subscript_correction}]]]]] -@endExample +@display +@group +@var{width}[@code{,}@var{height}[@code{,}@var{depth}[@code{,}@var{italic-correction} + [@code{,}@var{left-italic-correction}[@code{,}@var{subscript-correction}]]]]] +@end group +@end display @noindent There must not be any spaces between these subfields (it has been split @@ -9965,22 +14242,21 @@ here into two lines for better legibility only). Missing subfields are assumed to be@w{ }0. The subfields are all decimal integers. Since there is no associated binary format, these values are not required to fit into a variable of type @samp{char} as they are in @code{ditroff}. -The @var{width} subfield gives the width of the character. The -@var{height} subfield gives the height of the character (upwards is -positive); if a character does not extend above the baseline, it should -be given a zero height, rather than a negative height. The @var{depth} -subfield gives the depth of the character, that is, the distance below -the lowest point below the baseline to which the character extends -(downwards is positive); if a character does not extend below above the -baseline, it should be given a zero depth, rather than a negative depth. -The @var{italic_correction} subfield gives the amount of space that -should be added after the character when it is immediately to be -followed by a character from a roman font. The -@var{left_italic_correction} subfield gives the amount of space that -should be added before the character when it is immediately to be -preceded by a character from a roman font. The -@var{subscript_correction} gives the amount of space that should be -added after a character before adding a subscript. This should be less +The @var{width} subfield gives the width of the glyph. The @var{height} +subfield gives the height of the glyph (upwards is positive); if a +glyph does not extend above the baseline, it should be given a zero +height, rather than a negative height. The @var{depth} subfield gives +the depth of the glyph, that is, the distance from the baseline to the +lowest point below the baseline to which the glyph extends (downwards is +positive); if a glyph does not extend below the baseline, it should be +given a zero depth, rather than a negative depth. The +@var{italic-correction} subfield gives the amount of space that should +be added after the glyph when it is immediately to be followed by a +glyph from a roman font. The @var{left-italic-correction} subfield +gives the amount of space that should be added before the glyph when it +is immediately to be preceded by a glyph from a roman font. The +@var{subscript-correction} gives the amount of space that should be +added after a glyph before adding a subscript. This should be less than the italic correction. A line in the @code{charset} section can also have the format @@ -9990,7 +14266,7 @@ A line in the @code{charset} section can also have the format @endExample @noindent -This indicates that @var{name} is just another name for the character +This indicates that @var{name} is just another name for the glyph mentioned in the preceding line. @kindex kernpairs @@ -10002,17 +14278,16 @@ sequence of lines of the form: @endExample @noindent -This means that when character @var{c1} appears next to character -@var{c2} the space between them should be increased by@w{ }@var{n}. -Most entries in the kernpairs section have a negative value for@w{ -}@var{n}. +This means that when glyph @var{c1} appears next to glyph @var{c2} +the space between them should be increased by@w{ }@var{n}. Most +entries in the kernpairs section have a negative value for@w{ }@var{n}. @c ===================================================================== @c ===================================================================== -@node Installation, Request Index, File formats, Top +@node Installation, Copying This Manual, File formats, Top @chapter Installation @cindex installation @@ -10023,8 +14298,22 @@ Most entries in the kernpairs section have a negative value for@w{ @c ===================================================================== @c ===================================================================== -@node Request Index, Escape Index, Installation, Top -@chapter Request Index +@node Copying This Manual, Request Index, Installation, Top +@appendix Copying This Manual + +@menu +* GNU Free Documentation License:: License for copying this manual. +@end menu + +@include fdl.texi + + + +@c ===================================================================== +@c ===================================================================== + +@node Request Index, Escape Index, Copying This Manual, Top +@appendix Request Index Requests appear without the leading control character (normally either @samp{.} or @samp{'}). @@ -10037,7 +14326,10 @@ Requests appear without the leading control character (normally either @c ===================================================================== @node Escape Index, Operator Index, Request Index, Top -@chapter Escape Index +@appendix Escape Index + +Any escape sequence @code{\@var{X}} with @var{X} not in the list below +emits a warning, printing glyph @var{X}. @printindex es @@ -10047,7 +14339,7 @@ Requests appear without the leading control character (normally either @c ===================================================================== @node Operator Index, Register Index, Escape Index, Top -@chapter Operator Index +@appendix Operator Index @printindex op @@ -10057,7 +14349,15 @@ Requests appear without the leading control character (normally either @c ===================================================================== @node Register Index, Macro Index, Operator Index, Top -@chapter Register Index +@appendix Register Index + +The macro package or program a specific register belongs to is appended in +brackets. + +A register name@w{ }@code{x} consisting of exactly one character can be +accessed as @samp{\nx}. A register name @code{xx} consisting of exactly +two characters can be accessed as @samp{\n(xx}. Register names @code{xxx} +of any length can be accessed as @samp{\n[xxx]}. @printindex vr @@ -10067,7 +14367,10 @@ Requests appear without the leading control character (normally either @c ===================================================================== @node Macro Index, String Index, Register Index, Top -@chapter Macro Index +@appendix Macro Index + +The macro package a specific macro belongs to is appended in brackets. +They appear without the leading control character (normally @samp{.}). @printindex ma @@ -10077,7 +14380,16 @@ Requests appear without the leading control character (normally either @c ===================================================================== @node String Index, Glyph Name Index, Macro Index, Top -@chapter String Index +@appendix String Index + +The macro package or program a specific string belongs to is appended in +brackets. + +A string name@w{ }@code{x} consisting of exactly one character can be +accessed as @samp{\*x}. A string name @code{xx} consisting of exactly +two characters can be accessed as @samp{\*(xx}. String names @code{xxx} +of any length can be accessed as @samp{\*[xxx]}. + @printindex st @@ -10087,13 +14399,13 @@ Requests appear without the leading control character (normally either @c ===================================================================== @node Glyph Name Index, Font File Keyword Index, String Index, Top -@chapter Glyph Name Index +@appendix Glyph Name Index A glyph name @code{xx} consisting of exactly two characters can be accessed as @samp{\(xx}. Glyph names @code{xxx} of any length can be accessed as @samp{\[xxx]}. -@printindex gl +@c XXX @@ -10101,7 +14413,7 @@ accessed as @samp{\[xxx]}. @c ===================================================================== @node Font File Keyword Index, Program and File Index, Glyph Name Index, Top -@chapter Font File Keyword Index +@appendix Font File Keyword Index @printindex ky @@ -10111,7 +14423,7 @@ accessed as @samp{\[xxx]}. @c ===================================================================== @node Program and File Index, Concept Index, Font File Keyword Index, Top -@chapter Program and File Index +@appendix Program and File Index @printindex pg @@ -10121,12 +14433,9 @@ accessed as @samp{\[xxx]}. @c ===================================================================== @node Concept Index, , Program and File Index, Top -@chapter Concept Index +@appendix Concept Index @printindex cp - -@summarycontents -@contents @bye |
