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Diffstat (limited to 'contrib/file/file.man')
| -rw-r--r-- | contrib/file/file.man | 315 |
1 files changed, 172 insertions, 143 deletions
diff --git a/contrib/file/file.man b/contrib/file/file.man index 1215e69..fff7730 100644 --- a/contrib/file/file.man +++ b/contrib/file/file.man @@ -1,5 +1,5 @@ -.\" $File: file.man,v 1.79 2008/11/06 22:49:08 rrt Exp $ -.Dd October 9, 2008 +.\" $File: file.man,v 1.98 2011/12/08 12:12:46 rrt Exp $ +.Dd October 17, 2011 .Dt FILE __CSECTION__ .Os .Sh NAME @@ -7,18 +7,22 @@ .Nd determine file type .Sh SYNOPSIS .Nm -.Op Fl bchikLnNprsvz -.Op Fl -mime-type -.Op Fl -mime-encoding -.Op Fl f Ar namefile +.Bk -words +.Op Fl bchiklLNnprsvz0 +.Op Fl Fl apple +.Op Fl Fl mime-encoding +.Op Fl Fl mime-type +.Op Fl e Ar testname .Op Fl F Ar separator +.Op Fl f Ar namefile .Op Fl m Ar magicfiles -.Ar file +.Ar +.Ek .Nm .Fl C -.Op Fl m Ar magicfile +.Op Fl m Ar magicfiles .Nm -.Op Fl -help +.Op Fl Fl help .Sh DESCRIPTION This manual page documents version __VERSION__ of the .Nm @@ -42,12 +46,12 @@ terminal), .Em executable (the file contains the result of compiling a program in a form understandable to some -.Dv UNIX +.Tn UNIX kernel or another), or .Em data meaning anything else (data is usually -.Sq binary +.Dq binary or non-printable). Exceptions are well-known file formats (core files, tar archives) that are known to contain binary data. @@ -55,12 +59,12 @@ When modifying magic files or the program itself, make sure to .Em "preserve these keywords" . Users depend on knowing that all the readable files in a directory have the word -.Sq text +.Dq text printed. Don't do as Berkeley did and change -.Sq shell commands text +.Dq shell commands text to -.Sq shell script . +.Dq shell script . .Pp The filesystem tests are based on examining the return from a .Xr stat 2 @@ -70,8 +74,7 @@ or if it's some sort of special file. Any known file types appropriate to the system you are running on (sockets, symbolic links, or named pipes (FIFOs) on those systems that implement them) -are intuited if they are defined in -the system header file +are intuited if they are defined in the system header file .In sys/stat.h . .Pp The magic tests are used to check for files with data in @@ -85,13 +88,14 @@ and possibly .In exec.h in the standard include directory. These files have a -.Sq "magic number" +.Dq "magic number" stored in a particular place near the beginning of the file that tells the -.Dv UNIX operating system +.Tn UNIX +operating system that the file is a binary executable, and which of several types thereof. The concept of a -.Sq "magic" +.Dq "magic" has been applied by extension to data files. Any file with some invariant identifier at a small fixed offset into the file can usually be described in this way. @@ -100,7 +104,8 @@ magic file .Pa __MAGIC__.mgc , or the files in the directory .Pa __MAGIC__ -if the compiled file does not exist. In addition, if +if the compiled file does not exist. +In addition, if .Pa $HOME/.magic.mgc or .Pa $HOME/.magic @@ -117,10 +122,10 @@ in each set. If a file passes any of these tests, its character set is reported. ASCII, ISO-8859-x, UTF-8, and extended-ASCII files are identified as -.Sq text +.Dq text because they will be mostly readable on nearly any terminal; UTF-16 and EBCDIC are only -.Sq character data +.Dq character data because, while they contain text, it is text that will require translation before it can be read. @@ -138,8 +143,8 @@ has determined the character set used in a text-type file, it will attempt to determine in what language the file is written. The language tests look for particular strings (cf. -.In names.h -) that can appear anywhere in the first few blocks of a file. +.In names.h ) +that can appear anywhere in the first few blocks of a file. For example, the keyword .Em .br indicates that the file is most likely a @@ -156,37 +161,38 @@ archives). .Pp Any file that cannot be identified as having been written in any of the character sets listed above is simply said to be -.Sq data . +.Dq data . .Sh OPTIONS .Bl -tag -width indent -.It Fl b , -brief +.It Fl b , Fl Fl brief Do not prepend filenames to output lines (brief mode). -.It Fl c , -checking-printout +.It Fl C , Fl Fl compile +Write a +.Pa magic.mgc +output file that contains a pre-parsed version of the magic file or directory. +.It Fl c , Fl Fl checking-printout Cause a checking printout of the parsed form of the magic file. This is usually used in conjunction with the .Fl m flag to debug a new magic file before installing it. -.It Fl C , -compile -Write a -.Pa magic.mgc -output file that contains a pre-parsed version of the magic file or directory. -.It Fl e , -exclude Ar testname +.It Fl e , Fl Fl exclude Ar testname Exclude the test named in .Ar testname -from the list of tests made to determine the file type. Valid test names -are: -.Bl -tag -width +from the list of tests made to determine the file type. +Valid test names are: +.Bl -tag -width compress .It apptype .Dv EMX application type (only on EMX). -.It text -Various types of text files (this test will try to guess the text encoding, irrespective of the setting of the +.It ascii +Various types of text files (this test will try to guess the text +encoding, irrespective of the setting of the .Sq encoding option). .It encoding Different text encodings for soft magic tests. .It tokens -Looks for known tokens inside text files. +Ignored for backwards compatibility. .It cdf Prints details of Compound Document Files. .It compress @@ -198,7 +204,12 @@ Consults magic files. .It tar Examines tar files. .El -.It Fl f , -files-from Ar namefile +.It Fl F , Fl Fl separator Ar separator +Use the specified string as the separator between the filename and the +file result returned. +Defaults to +.Sq \&: . +.It Fl f , Fl Fl files-from Ar namefile Read the names of the files to be examined from .Ar namefile (one per line) @@ -209,71 +220,81 @@ or at least one filename argument must be present; to test the standard input, use .Sq - as a filename argument. -.It Fl F , -separator Ar separator -Use the specified string as the separator between the filename and the -file result returned. Defaults to -.Sq \&: . -.It Fl h , -no-dereference +Please note that +.Ar namefile +is unwrapped and the enclosed filenames are processed when this option is +encountered and before any further options processing is done. +This allows one to process multiple lists of files with different command line +arguments on the same +.Nm +invocation. +Thus if you want to set the delimiter, you need to do it before you specify +the list of files, like: +.Dq Fl F Ar @ Fl f Ar namefile , +instead of: +.Dq Fl f Ar namefile Fl F Ar @ . +.It Fl h , Fl Fl no-dereference option causes symlinks not to be followed -(on systems that support symbolic links). This is the default if the -environment variable +(on systems that support symbolic links). +This is the default if the environment variable .Dv POSIXLY_CORRECT is not defined. -.It Fl i , -mime +.It Fl i , Fl Fl mime Causes the file command to output mime type strings rather than the more -traditional human readable ones. Thus it may say +traditional human readable ones. +Thus it may say .Sq text/plain; charset=us-ascii rather than -.Sq ASCII text . -In order for this option to work, file changes the way -it handles files recognized by the command itself (such as many of the -text file types, directories etc), and makes use of an alternative -.Sq magic -file. -(See the FILES section, below). -.It Fl -mime-type , -mime-encoding +.Dq ASCII text . +.It Fl Fl mime-type , Fl Fl mime-encoding Like .Fl i , but print only the specified element(s). -.It Fl k , -keep-going -Don't stop at the first match, keep going. Subsequent matches will be +.It Fl k , Fl Fl keep-going +Don't stop at the first match, keep going. +Subsequent matches will be have the string .Sq "\[rs]012\- " prepended. (If you want a newline, see the -.Sq "\-r" +.Fl r option.) -.It Fl L , -dereference +.It Fl l , Fl Fl list +Print information about the strength of each magic pattern. +.It Fl L , Fl Fl dereference option causes symlinks to be followed, as the like-named option in .Xr ls 1 (on systems that support symbolic links). This is the default if the environment variable -.Dv POSIXLY_CORRECT +.Ev POSIXLY_CORRECT is defined. -.It Fl m , -magic-file Ar list +.It Fl l +Shows sorted patterns list in the order which is used for the matching. +.It Fl m , Fl Fl magic-file Ar magicfiles Specify an alternate list of files and directories containing magic. This can be a single item, or a colon-separated list. -If a compiled magic file is found alongside a file or directory, it will be used instead. -.It Fl n , -no-buffer +If a compiled magic file is found alongside a file or directory, +it will be used instead. +.It Fl N , Fl Fl no-pad +Don't pad filenames so that they align in the output. +.It Fl n , Fl Fl no-buffer Force stdout to be flushed after checking each file. This is only useful if checking a list of files. It is intended to be used by programs that want filetype output from a pipe. -.It Fl N , -no-pad -Don't pad filenames so that they align in the output. -.It Fl p , -preserve-date +.It Fl p , Fl Fl preserve-date On systems that support -.Xr utime 2 +.Xr utime 3 or .Xr utimes 2 , attempt to preserve the access time of files analyzed, to pretend that .Nm never read them. -.It Fl r , -raw +.It Fl r , Fl Fl raw Don't translate unprintable characters to \eooo. Normally .Nm translates unprintable characters to their octal representation. -.It Fl s , -special-files +.It Fl s , Fl Fl special-files Normally, .Nm only attempts to read and determine the type of argument files which @@ -293,16 +314,18 @@ This option also causes to disregard the file size as reported by .Xr stat 2 since on some systems it reports a zero size for raw disk partitions. -.It Fl v , -version +.It Fl v , Fl Fl version Print the version of the program and exit. -.It Fl z , -uncompress +.It Fl z , Fl Fl uncompress Try to look inside compressed files. -.It Fl 0 , -print0 +.It Fl 0 , Fl Fl print0 Output a null character .Sq \e0 -after the end of the filename. Nice to +after the end of the filename. +Nice to .Xr cut 1 -the output. This does not affect the separator which is still printed. +the output. +This does not affect the separator which is still printed. .It Fl -help Print a help message and exit. .El @@ -315,7 +338,7 @@ Directory containing default magic files. .El .Sh ENVIRONMENT The environment variable -.Dv MAGIC +.Ev MAGIC can be used to set the default magic file name. If that variable is set, then .Nm @@ -323,26 +346,31 @@ will not attempt to open .Pa $HOME/.magic . .Nm adds -.Sq .mgc +.Dq Pa .mgc to the value of this variable as appropriate. +However, +.Pa file +has to exist in order for +.Pa file.mime +to be considered. The environment variable -.Dv POSIXLY_CORRECT +.Ev POSIXLY_CORRECT controls (on systems that support symbolic links), whether .Nm -will attempt to follow symlinks or not. If set, then +will attempt to follow symlinks or not. +If set, then .Nm -follows symlink, otherwise it does not. This is also controlled -by the +follows symlink, otherwise it does not. +This is also controlled by the .Fl L and .Fl h options. .Sh SEE ALSO .Xr magic __FSECTION__ , -.Xr strings 1 , +.Xr hexdump 1 , .Xr od 1 , -.Xr hexdump 1, -.Xr file 1posix +.Xr strings 1 , .Sh STANDARDS CONFORMANCE This program is believed to exceed the System V Interface Definition of FILE(CMD), as near as one can determine from the vague language @@ -358,12 +386,12 @@ is that this version treats any white space as a delimiter, so that spaces in pattern strings must be escaped. For example, .Bd -literal -offset indent ->10 string language impress\ (imPRESS data) +\*[Gt]10 string language impress\ (imPRESS data) .Ed .Pp in an existing magic file would have to be changed to .Bd -literal -offset indent ->10 string language\e impress (imPRESS data) +\*[Gt]10 string language\e impress (imPRESS data) .Ed .Pp In addition, in this version, if a pattern string contains a backslash, @@ -381,13 +409,13 @@ in an existing magic file would have to be changed to SunOS releases 3.2 and later from Sun Microsystems include a .Nm command derived from the System V one, but with some extensions. -My version differs from Sun's only in minor ways. +This version differs from Sun's only in minor ways. It includes the extension of the -.Sq & +.Sq \*[Am] operator, used as, for example, .Bd -literal -offset indent ->16 long&0x7fffffff >0 not stripped +\*[Gt]16 long\*[Am]0x7fffffff \*[Gt]0 not stripped .Ed .Sh MAGIC DIRECTORY The magic file entries have been collected from various sources, @@ -405,13 +433,13 @@ If your old command uses a magic file, keep the old magic file around for comparison purposes (rename it to -.Pa __MAGIC__.orig ). +.Pa __MAGIC__.orig ) . .Sh EXAMPLES .Bd -literal -offset indent $ file file.c file /dev/{wd0a,hda} file.c: C program text file: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), - dynamically linked (uses shared libs), stripped + dynamically linked (uses shared libs), stripped /dev/wd0a: block special (0/0) /dev/hda: block special (3/0) @@ -450,33 +478,48 @@ the external list of magic types. This slowed the program down slightly but made it a lot more flexible. .Pp This program, based on the System V version, -was written by Ian Darwin <ian@darwinsys.com> +was written by Ian Darwin +.Aq ian@darwinsys.com without looking at anybody else's source code. .Pp John Gilmore revised the code extensively, making it better than the first version. Geoff Collyer found several inadequacies and provided some magic file entries. -Contributions by the `&' operator by Rob McMahon, cudcv@warwick.ac.uk, 1989. +Contributions by the +.Sq \*[Am] +operator by Rob McMahon, +.Aq cudcv@warwick.ac.uk , +1989. .Pp -Guy Harris, guy@netapp.com, made many changes from 1993 to the present. +Guy Harris, +.Aq guy@netapp.com , +made many changes from 1993 to the present. +1989. .Pp Primary development and maintenance from 1990 to the present by -Christos Zoulas (christos@astron.com). +Christos Zoulas +.Aq christos@astron.com . .Pp -Altered by Chris Lowth, chris@lowth.com, 2000: -Handle the +Altered by Chris Lowth +.Aq chris@lowth.com , +2000: handle the .Fl i option to output mime type strings, using an alternative magic file and internal logic. .Pp -Altered by Eric Fischer (enf@pobox.com), July, 2000, +Altered by Eric Fischer +.Aq enf@pobox.com , +July, 2000, to identify character codes and attempt to identify the languages of non-ASCII files. .Pp -Altered by Reuben Thomas (rrt@sc3d.org), 2007 to 2008, to improve MIME -support and merge MIME and non-MIME magic, support directories as well -as files of magic, apply many bug fixes and improve the build system. +Altered by Reuben Thomas +.Aq rrt@sc3d.org , +2007-2011, to improve MIME support, merge MIME and non-MIME magic, +support directories as well as files of magic, apply many bug fixes, +update and fix a lot of magic, improve the build system, improve the +documentation, and rewrite the Python bindings in pure Python. .Pp The list of contributors to the .Sq magic @@ -487,63 +530,49 @@ Many contributors are listed in the source files. .Sh LEGAL NOTICE Copyright (c) Ian F. Darwin, Toronto, Canada, 1986-1999. Covered by the standard Berkeley Software Distribution copyright; see the file -LEGAL.NOTICE in the source distribution. +COPYING in the source distribution. .Pp The files -.Dv tar.h +.Pa tar.h and -.Dv is_tar.c +.Pa is_tar.c were written by John Gilmore from his public-domain .Xr tar 1 program, and are not covered by the above license. +.Sh RETURN CODE +.Nm +returns 0 on success, and non-zero on error. .Sh BUGS .Pp -There must be a better way to automate the construction of the Magic -file from all the glop in Magdir. -What is it? +Please report bugs and send patches to the bug tracker at +.Pa http://bugs.gw.com/ +or the mailing list at +.Aq file@mx.gw.com . +.Sh TODO .Pp -.Nm -uses several algorithms that favor speed over accuracy, -thus it can be misled about the contents of -text -files. +Fix output so that tests for MIME and APPLE flags are not needed all +over the place, and actual output is only done in one place. This +needs a design. Suggestion: push possible outputs on to a list, then +pick the last-pushed (most specific, one hopes) value at the end, or +use a default if the list is empty. This should not slow down evaluation. .Pp -The support for text files (primarily for programming languages) -is simplistic, inefficient and requires recompilation to update. +Continue to squash all magic bugs. See Debian BTS for a good source. .Pp -The list of keywords in -.Dv ascmagic -probably belongs in the Magic file. -This could be done by using some keyword like -.Sq * -for the offset value. +Store arbitrarily long strings, for example for %s patterns, so that +they can be printed out. Fixes Debian bug #271672. Would require more +complex store/load code in apprentice. .Pp -Complain about conflicts in the magic file entries. -Make a rule that the magic entries sort based on file offset rather -than position within the magic file? +Add syntax for relative offsets after current level (Debian bug #466037). .Pp -The program should provide a way to give an estimate -of -.Sq how good -a guess is. -We end up removing guesses (e.g. -.Sq From\ -as first 5 chars of file) because -they are not as good as other guesses (e.g. -.Sq Newsgroups: -versus -.Sq Return-Path: -). -Still, if the others don't pan out, it should be possible to use the -first guess. +Make file -ki work, i.e. give multiple MIME types. .Pp -This manual page, and particularly this section, is too long. -.Sh RETURN CODE -.Nm -returns 0 on success, and non-zero on error. +Add a zip library so we can peek inside Office2007 documents to +figure out what they are. +.Pp +Add an option to print URLs for the sources of the file descriptions. .Sh AVAILABILITY You can obtain the original author's latest version by anonymous FTP on -.Dv ftp.astron.com +.Pa ftp.astron.com in the directory -.Dv /pub/file/file-X.YZ.tar.gz +.Pa /pub/file/file-X.YZ.tar.gz . |
