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diff --git a/bin/csh/USD.doc/Makefile b/bin/csh/USD.doc/Makefile
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--- /dev/null
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@@ -0,0 +1,7 @@
+#	@(#)Makefile	8.1 (Berkeley) 8/14/93
+
+DIR=	usd/04.csh
+SRCS=	tabs csh.1 csh.2 csh.3 csh.4 csh.a csh.g
+MACROS= -ms
+
+.include <bsd.doc.mk>
diff --git a/bin/csh/USD.doc/csh.1 b/bin/csh/USD.doc/csh.1
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--- /dev/null
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+.\" Copyright (c) 1980, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)csh.1	8.1 (Berkeley) 6/8/93
+.\"
+.EH 'USD:4-%''An Introduction to the C shell'
+.OH 'An Introduction to the C shell''USD:4-%'
+.\".RP
+.TL
+An Introduction to the C shell
+.AU
+William Joy
+(revised for 4.3BSD by Mark Seiden)
+.AI
+Computer Science Division
+.br
+Department of Electrical Engineering and Computer Science
+.br
+University of California, Berkeley
+.br
+Berkeley, California 94720
+.AB
+.I Csh
+is a new command language interpreter for
+.UX
+systems.
+It incorporates good features of other shells and a
+.I history
+mechanism similar to the
+.I redo
+of \s-2INTERLISP\s0.
+While incorporating many features of other shells which make
+writing shell programs (shell scripts) easier,
+most of the features unique to
+.I csh
+are designed more for the interactive \s-2UNIX\s0 user.
+.PP
+\s-2UNIX\s0
+users who have read a general introduction to the system
+will find a valuable basic explanation of the shell here.
+Simple terminal interaction with
+.I csh
+is possible after reading just the first section of this document.
+The second section describes the shell's capabilities which you can
+explore after you have begun to become acquainted with the shell.
+Later sections introduce features which are useful, but not necessary
+for all users of the shell.
+.PP
+Additional information includes an appendix listing special characters of the shell
+and a glossary of terms and commands introduced in this manual.
+.AE
+.SH
+.if n .ND
+Introduction
+.PP
+A
+.I shell
+is a command language interpreter.
+.I Csh
+is the name of one particular command interpreter on
+\s-2UNIX\s0.
+The primary purpose of
+.I csh
+is to translate command lines typed at a terminal into
+system actions, such as invocation of other programs.
+.I Csh
+is a user program just like any you might write.
+Hopefully,
+.I csh
+will be a very useful program for you
+in interacting with the \s-2UNIX\s0 system.
+.PP
+In addition to this document, you will want to refer to a copy
+of the \s-2UNIX\s0 User Reference Manual.
+The
+.I csh
+documentation in section 1 of the manual provides a full description of all
+features of the shell and is the definitive reference for questions
+about the shell.
+.PP
+Many words in this document are shown in
+.I italics.
+These are important words;
+names of commands, and words which have special meaning in discussing
+the shell and \s-2UNIX\s0.
+Many of the words are defined in a glossary at the end of this document.
+If you don't know what is meant by a word, you should look
+for it in the glossary.
+.SH
+Acknowledgements
+.PP
+Numerous people have provided good input about previous versions
+of 
+.I csh
+and aided in its debugging and in the debugging of its documentation.
+I would especially like to thank Michael Ubell
+who made the crucial observation that history commands could be
+done well over the word structure of input text, and implemented
+a prototype history mechanism in an older version of the shell.
+Eric Allman has also provided a large number of useful comments on the
+shell, helping to unify those concepts which are present and to identify
+and eliminate useless and marginally useful features.
+Mike O'Brien suggested the pathname hashing
+mechanism which speeds command execution.
+Jim Kulp added the job control and directory stack primitives and
+added their documentation to this introduction.
+.br
+.bp
+.NH
+Terminal usage of the shell
+.NH 2
+The basic notion of commands
+.PP
+A
+.I shell
+in
+\s-2UNIX\s0
+acts mostly as a medium through which other
+.I programs
+are invoked.
+While it has a set of
+.I builtin
+functions which it performs directly,
+most commands cause execution of programs that are, in fact,
+external to the shell.
+The shell is thus distinguished from the command interpreters of other
+systems both by the fact that it is just a user program, and by the fact
+that it is used almost exclusively as a mechanism for invoking other programs.
+.PP
+.I Commands
+in the \s-2UNIX\s0 system consist of a list of strings or
+.I words
+interpreted as a
+.I "command name"
+followed by
+.I arguments.
+Thus the command
+.DS
+mail bill
+.DE
+consists of two words.
+The first word
+.I mail
+names the command to be executed, in this case the
+mail program which sends messages to other users.
+The shell uses the name of the command in attempting to execute it for you.
+It will look in a number of
+.I directories
+for a file with the name
+.I mail
+which is expected to contain the mail program.
+.PP
+The rest of the words of the command are given as
+.I arguments
+to the command itself when it is executed.
+In this case we specified also the argument
+.I bill
+which is interpreted by the
+.I mail
+program to be the name of a user to whom mail is to be sent.
+In normal terminal usage we might use the
+.I mail
+command as follows.
+.DS
+% mail bill
+I have a question about the csh documentation.
+My document seems to be missing page 5.
+Does a page five exist?
+	Bill
+EOT
+%
+.DE
+.PP
+Here we typed a message to send to
+.I bill
+and ended this message with a ^D which sent an end-of-file to
+the mail program.
+(Here and throughout this document, the notation ``^\fIx\fR''
+is to be read ``control-\fIx\fR'' and represents the striking of the \fIx\fR
+key while the control key is held down.)
+The mail program
+then echoed the characters `EOT' and transmitted our message.
+The characters `% ' were printed before and after the mail command 
+by the shell to indicate that input was needed.
+.PP
+After typing the `% ' prompt the shell was reading command input from
+our terminal.
+We typed a complete command `mail bill'.
+The shell then executed the
+.I mail
+program with argument
+.I bill
+and went dormant waiting for it to complete.
+The mail program then read input from our terminal until we signalled
+an end-of-file via typing a ^D after which the shell noticed
+that mail had completed
+and signaled us that it was ready to read from the terminal again by
+printing another `% ' prompt.
+.PP
+This is the essential pattern of all interaction with \s-2UNIX\s0
+through the shell.
+A complete command is typed at the terminal, the shell executes
+the command and when this execution completes, it prompts for a new command.
+If you run the editor for an hour, the shell will patiently wait for
+you to finish editing and obediently prompt you again whenever you finish
+editing.
+.PP
+An example of a useful command you can execute now is the
+.I tset
+command, which sets the default
+.I erase
+and
+.I kill
+characters on your terminal \- the erase character erases the last
+character you typed and the kill character erases the entire line you
+have entered so far.
+By default, the erase character is the delete key (equivalent to `^?')
+and the kill character is `^U'.  Some people prefer to make the erase character
+the backspace key (equivalent to `^H').
+You can make this be true by typing
+.DS
+tset \-e
+.DE
+which tells the program
+.I tset
+to set the erase character to tset's default setting for this character
+(a backspace).
+.NH 2
+Flag arguments
+.PP
+A useful notion in \s-2UNIX\s0 is that of a
+.I flag
+argument.
+While many arguments to commands specify file names or user names,
+some arguments rather specify an optional capability of the command
+which you wish to invoke.
+By convention, such arguments begin with the character `\-' (hyphen).
+Thus the command
+.DS
+ls
+.DE
+will produce a list of the files in the current
+.I "working directory" .
+The option
+.I \-s
+is the size option, and
+.DS
+ls \-s
+.DE
+causes
+.I ls
+to also give, for each file the size of the file in blocks of 512
+characters.
+The manual section for each command in the \s-2UNIX\s0 reference manual
+gives the available options for each command.
+The
+.I ls
+command has a large number of useful and interesting options.
+Most other commands have either no options or only one or two options.
+It is hard to remember options of commands which are not used very
+frequently, so most \s-2UNIX\s0 utilities perform only one or two functions
+rather than having a large number of hard to remember options.
+.NH 2
+Output to files
+.PP
+Commands that normally read input or write output on the terminal 
+can also be executed with this input and/or output done to
+a file.
+.PP
+Thus suppose we wish to save the current date in a file called `now'.
+The command
+.DS
+date
+.DE
+will print the current date on our terminal.
+This is because our terminal is the default
+.I "standard output"
+for the date command and the date command prints the date on its
+standard output.
+The shell lets us
+.I redirect
+the
+.I "standard output"
+of a command through a
+notation using the
+.I metacharacter
+`>' and the name of the file where output is to be placed.
+Thus the command
+.DS
+date > now
+.DE
+runs the
+.I date
+command such that its standard output is
+the file `now' rather than the terminal.
+Thus this command places the current date and time into the file `now'.
+It is important to know that the
+.I date
+command was unaware that its output was going to a file rather than
+to the terminal.
+The shell performed this
+.I redirection
+before the command began executing.
+.PP
+One other thing to note here is that the file `now'
+need not have existed before the
+.I date
+command was executed; the shell would have created the file if it did
+not exist.
+And if the file did exist?
+If it had existed previously these previous contents would have been discarded!
+A shell option
+.I noclobber
+exists to prevent this from happening accidentally;
+it is discussed in section 2.2.
+.PP
+The system normally keeps files which you create with `>' and all other files.
+Thus the default is for files to be permanent.  If you wish to create a file
+which will be removed automatically, you can begin its name with a `#'
+character, this `scratch' character denotes the fact that the file will
+be a scratch file.*
+.FS
+*Note that if your erase character is a `#', you will have to precede the
+`#' with a `\e'.  The fact that the `#' character is the old (pre-\s-2CRT\s0)
+standard erase character means that it seldom appears in a file name, and
+allows this convention to be used for scratch files.  If you are using a
+\s-2CRT\s0, your erase character should be a ^H, as we demonstrated
+in section 1.1 how this could be set up.
+.FE
+The system will remove such files after a couple of days,
+or sooner if file space becomes very tight.
+Thus, in running the
+.I date
+command above, we don't really want to save the output forever, so we
+would more likely do
+.DS
+date > #now
+.DE
+.NH 2
+Metacharacters in the shell
+.PP
+The shell has a large number of
+special characters (like `>')
+which indicate special functions.
+We say that these notations have
+.I syntactic
+and
+.I semantic
+meaning to the shell.
+In general, most characters which are neither letters nor digits
+have special meaning to the shell.
+We shall shortly learn a means of
+.I quotation
+which allows us to use
+.I metacharacters
+without the shell treating them in any special way.
+.PP
+Metacharacters normally have effect only when the shell is reading
+our input.
+We need not worry about placing shell metacharacters in a letter
+we are sending via
+.I mail,
+or when we are typing in text or data to some other program.
+Note that the shell is only reading input when it has prompted with
+`% ' (although we can type our input even before it prompts).
+.NH 2
+Input from files; pipelines
+.PP
+We learned above how to
+.I redirect
+the
+.I "standard output"
+of a command
+to a file.
+It is also possible to redirect the
+.I "standard input"
+of a command from a file.
+This is not often necessary since most commands will read from
+a file whose name is given as an argument.
+We can give the command
+.DS
+sort < data
+.DE
+to run the
+.I sort
+command with standard input, where the command normally
+reads its input, from the file
+`data'.
+We would more likely say
+.DS
+sort data
+.DE
+letting the
+.I sort
+command open the file
+`data'
+for input itself since this is less to type.
+.PP
+We should note that if we just typed
+.DS
+sort
+.DE
+then the sort program would sort lines from its
+.I "standard input."
+Since we did not
+.I redirect
+the standard input, it would sort lines as we typed them on the terminal
+until we typed a ^D to indicate an end-of-file.
+.PP
+A most useful capability is the ability to combine the standard output
+of one command with the standard input of another, i.e. to run the
+commands in a sequence known as a
+.I pipeline.
+For instance the command
+.DS
+ls \-s
+.DE
+normally produces a list of the files in our directory with the size
+of each in blocks of 512 characters.
+If we are interested in learning which of our files is largest we
+may wish to have this sorted by size rather than by name, which is
+the default way in which
+.I ls
+sorts.
+We could look at the many options of
+.I ls
+to see if there was an option to do this but would eventually discover
+that there is not.
+Instead we can use a couple of simple options of the
+.I sort
+command, combining it with
+.I ls
+to get what we want.
+.PP
+The
+.I \-n
+option of sort specifies a numeric sort rather than an alphabetic sort.
+Thus
+.DS
+ls \-s | sort \-n
+.DE
+specifies that the output of the
+.I ls
+command run with the option
+.I \-s
+is to be
+.I piped
+to the command
+.I sort
+run with the numeric sort option.
+This would give us a sorted list of our files by size, but with the
+smallest first.
+We could then use the
+.I \-r
+reverse sort option and the
+.I head
+command in combination with the previous command doing
+.DS
+ls \-s | sort \-n \-r | head \-5
+.DE
+Here we have taken a list of our files sorted alphabetically,
+each with the size in blocks.
+We have run this to the standard input of the
+.I sort
+command asking it to sort numerically in reverse order (largest first).
+This output has then been run into the command
+.I head
+which gives us the first few lines.
+In this case we have asked
+.I head
+for the first 5 lines.
+Thus this command gives us the names and sizes of our 5 largest files.
+.PP
+The notation introduced above is called the
+.I pipe
+mechanism.
+Commands separated by `\||\|' characters are connected together by the
+shell and the standard output of each is run into the standard input of the
+next.
+The leftmost command in a pipeline will normally take its standard
+input from the terminal and the rightmost will place its standard
+output on the terminal.
+Other examples of pipelines will be given later when we discuss the
+history mechanism;
+one important use of pipes which is illustrated there is in the
+routing of information to the line printer.
+.NH 2
+Filenames
+.PP
+Many commands to be executed will need the names of files as arguments.
+\s-2UNIX\s0
+.I pathnames
+consist of a number of
+.I components
+separated by `/'.
+Each component except the last names a directory in which the next
+component resides, in effect specifying the
+.I path
+of directories to follow to reach the file.
+Thus the pathname
+.DS
+/etc/motd
+.DE
+specifies a file in the directory
+`etc'
+which is a subdirectory of the
+.I root
+directory `/'.
+Within this directory the file named is `motd' which stands
+for `message of the day'.
+A
+.I pathname
+that begins with a slash is said to be an
+.I absolute
+pathname since it is specified from the absolute top of the entire
+directory hierarchy of the system (the
+.I root ).
+.I Pathnames
+which do not begin with `/' are interpreted as starting in the current
+.I "working directory" ,
+which is, by default, your
+.I home
+directory and can be changed dynamically by the
+.I cd
+change directory command.
+Such pathnames are said to be
+.I relative
+to the working directory since they are found by starting
+in the working directory and descending to lower levels of directories
+for each
+.I component
+of the pathname.  If the pathname contains no slashes at all then the
+file is contained in the working directory itself and the pathname is merely
+the name of the file in this directory.
+Absolute pathnames have no relation
+to the working directory.
+.PP
+Most filenames consist of a number of alphanumeric characters and
+`.'s (periods).
+In fact, all printing characters except `/' (slash) may appear in filenames.
+It is inconvenient to have most non-alphabetic characters in filenames
+because many of these have special meaning to the shell.
+The character `.' (period) is not a shell-metacharacter and is often used
+to separate the
+.I extension
+of a file name from the base of the name.
+Thus
+.DS
+prog.c prog.o prog.errs prog.output
+.DE
+are four related files.
+They share a
+.I base
+portion of a name
+(a base portion being that part of the name that is left when a trailing
+`.' and following characters which are not `.' are stripped off).
+The file
+`prog.c'
+might be the source for a C program,
+the file `prog.o' the corresponding object file,
+the file
+`prog.errs' the errors resulting from a compilation of the program
+and the file
+`prog.output' the output of a run of the program.
+.PP
+If we wished to refer to all four of these files in a command, we could
+use the notation
+.DS
+prog.*
+.DE
+This expression is expanded by the shell, before the command to which it is
+an argument is executed, into a list of names which begin with `prog.'.
+The character `*' here matches any sequence (including the empty sequence)
+of characters in a file name.
+The names which match are alphabetically sorted and placed in the
+.I "argument list"
+of the command.
+Thus the command
+.DS
+echo prog.*
+.DE
+will echo the names
+.DS
+prog.c prog.errs prog.o prog.output
+.DE
+Note that the names are in sorted order here, and a different
+order than we listed them above.
+The
+.I echo
+command receives four words as arguments, even though we only typed
+one word as as argument directly.
+The four words were generated by
+.I "filename expansion"
+of the one input word.
+.PP
+Other notations for
+.I "filename expansion"
+are also available.
+The character `?' matches any single character in a filename.
+Thus
+.DS
+echo ? \|?? \|???
+.DE
+will echo a line of filenames; first those with one character names,
+then those with two character names, and finally those with three
+character names.
+The names of each length will be independently sorted.
+.PP
+Another mechanism consists of a sequence of characters between `[' and `]'.
+This metasequence matches any single character from the enclosed set.
+Thus
+.DS
+prog.[co]
+.DE
+will match
+.DS
+prog.c prog.o
+.DE
+in the example above.
+We can also place two characters around a `\-' in this notation to denote
+a range.
+Thus
+.DS
+chap.[1\-5]
+.DE
+might match files
+.DS
+chap.1 chap.2 chap.3 chap.4 chap.5
+.DE
+if they existed.
+This is shorthand for
+.DS
+chap.[12345]
+.DE
+and otherwise equivalent.
+.PP
+An important point to note is that if a list of argument words to
+a command (an
+.I "argument list)"
+contains filename expansion syntax, and if this filename expansion syntax
+fails to match any existing file names, then the shell considers this
+to be an error and prints a diagnostic
+.DS
+No match.
+.DE
+and does not execute the command.
+.PP
+Another very important point is that files with the character `.' at the
+beginning are treated specially.
+Neither `*' or `?' or the `[' `]' mechanism will match it.
+This prevents accidental matching of the filenames `.' and `..'
+in the working directory which have special meaning to the system,
+as well as other files such as 
+.I \&.cshrc
+which are not normally
+visible.
+We will discuss the special role of the file
+.I \&.cshrc
+later.
+.PP
+Another filename expansion mechanism gives access to the pathname of
+the
+.I home
+directory of other users.
+This notation consists of the character `~' (tilde) followed by another user's
+login name.
+For instance the word `~bill' would map to the pathname `/usr/bill'
+if the home directory for `bill' was `/usr/bill'.
+Since, on large systems, users may have login directories scattered over
+many different disk volumes with different prefix directory names,
+this notation provides a convenient way of accessing the files
+of other users.
+.PP
+A special case of this notation consists of a `~' alone, e.g. `~/mbox'.
+This notation is expanded by the shell into the file `mbox' in your
+.I home
+directory, i.e. into `/usr/bill/mbox' for me on Ernie Co-vax, the UCB
+Computer Science Department VAX machine, where this document was prepared.
+This can be very useful if you have used
+.I cd
+to change to another directory and have found a file you wish to
+copy using
+.I cp.
+If I give the command
+.DS
+cp thatfile ~
+.DE
+the shell will expand this command to
+.DS
+cp thatfile /usr/bill
+.DE
+since my home directory is /usr/bill.
+.PP
+There also exists a mechanism using the characters `{' and `}' for
+abbreviating a set of words which have common parts but cannot
+be abbreviated by the above mechanisms because they are not files,
+are the names of files which do not yet exist,
+are not thus conveniently described.
+This mechanism will be described much later,
+in section 4.2,
+as it is used less frequently.
+.NH 2
+Quotation
+.PP
+We have already seen a number of metacharacters used by the shell.
+These metacharacters pose a problem in that we cannot use them directly 
+as parts of words.
+Thus the command
+.DS
+echo *
+.DE
+will not echo the character `*'.
+It will either echo an sorted list of filenames in the
+current
+.I "working directory,"
+or print the message `No match' if there are 
+no files in the working directory.
+.PP
+The recommended mechanism for placing characters which are neither numbers,
+digits, `/', `.' or `\-' in an argument word to a command is to enclose
+it with single quotation characters `\'', i.e.
+.DS
+echo \'*\'
+.DE
+There is one special character `!' which is used by the
+.I history
+mechanism of the shell and which cannot be
+.I escaped
+by placing it within `\'' characters.
+It and the character `\'' itself can be preceded by a single `\e'
+to prevent their special meaning.
+Thus
+.DS
+echo \e\'\e!
+.DE
+prints
+.DS
+\'!
+.DE
+These two mechanisms suffice to place any printing character into a word
+which is an argument to a shell command.  They can be combined, as in
+.DS
+echo \e\'\'*\'
+.DE
+which prints
+.DS
+\'*
+.DE
+since the first `\e' escaped the first `\'' and the `*' was enclosed
+between `\'' characters.
+.NH 2
+Terminating commands
+.PP
+When you are executing a command and the shell is
+waiting for it to complete there are several ways
+to force it to stop.
+For instance if you type the command
+.DS
+cat /etc/passwd
+.DE
+the system will print a copy of a list of all users of the system
+on your terminal.
+This is likely to continue for several minutes unless you stop it.
+You can send an
+\s-2INTERRUPT\s0
+.I signal
+to the
+.I cat
+command by typing ^C on your terminal.*
+.FS
+*On some older Unix systems the \s-2DEL\s0 or \s-2RUBOUT\s0 key
+has the same effect. "stty all" will tell you the INTR key value.
+.FE
+Since
+.I cat
+does not take any precautions to avoid or otherwise handle this signal
+the
+\s-2INTERRUPT\s0
+will cause it to terminate.
+The shell notices that
+.I cat
+has terminated and prompts you again with `% '.
+If you hit \s-2INTERRUPT\s0 again, the shell will just
+repeat its prompt since it handles \s-2INTERRUPT\s0 signals
+and chooses to continue to execute commands rather than terminating
+like
+.I cat
+did, which would have the effect of logging you out.
+.PP
+Another way in which many programs terminate is when they get an end-of-file
+from their standard input.
+Thus the
+.I mail
+program in the first example above was terminated when we typed a ^D
+which generates an end-of-file from the standard input.
+The shell also terminates when it gets an end-of-file printing `logout';
+\s-2UNIX\s0 then logs you off the system.
+Since this means that typing too many ^D's can accidentally log us off,
+the shell has a mechanism for preventing this.
+This 
+.I ignoreeof
+option will be discussed in section 2.2.
+.PP
+If a command has its standard input redirected from a file, then it will
+normally terminate when it reaches the end of this file.
+Thus if we execute
+.DS
+mail bill < prepared.text
+.DE
+the mail command will terminate without our typing a ^D.
+This is because it read to the end-of-file of our file
+`prepared.text' in which we placed a message for `bill' with an editor program.
+We could also have done
+.DS
+cat prepared.text \||\| mail bill
+.DE
+since the
+.I cat
+command would then have written the text through the pipe to the
+standard input of the mail command.
+When the
+.I cat
+command completed it would have terminated,
+closing down the pipeline
+and the
+.I mail
+command would have received an end-of-file from it and terminated.
+Using a pipe here is more complicated than redirecting input
+so we would more likely use the first form.
+These commands could also have been stopped by sending an \s-2INTERRUPT\s0.
+.PP
+Another possibility for stopping a command is to suspend its execution
+temporarily, with the possibility of continuing execution later.  This is
+done by sending a \s-2STOP\s0 signal via typing a ^Z.
+This signal causes all commands running on the terminal
+(usually one but more if a pipeline is executing) to become suspended.
+The shell notices that the command(s) have been suspended, types
+`Stopped' and then prompts for a new command.
+The previously executing command has been suspended, but otherwise
+unaffected by the \s-2STOP\s0 signal.  Any other commands can be executed
+while the original command remains suspended.  The suspended command can
+be continued using the
+.I fg
+command with no arguments.  The shell will then retype the command
+to remind you which command is being continued, and cause the command
+to resume execution.  Unless any input files in use by the suspended
+command have been changed in the meantime, the suspension has no effect
+whatsoever on the execution of the command.  This feature can be very useful
+during editing, when you need to look at another file before continuing. An
+example of command suspension follows.
+.DS
+% mail harold
+Someone just copied a big file into my directory and its name is
+^Z
+Stopped
+% ls
+funnyfile
+prog.c
+prog.o
+% jobs
+.ta 1.75i
+[1]  + Stopped	mail harold
+% fg
+mail harold
+funnyfile. Do you know who did it?
+EOT
+%
+.so tabs
+.DE
+In this example someone was sending a message to Harold and forgot the
+name of the file he wanted to mention.  The mail command was suspended
+by typing ^Z.  When the shell noticed that the mail program was
+suspended, it typed `Stopped' and prompted for a new command.  Then the
+.I ls
+command was typed to find out the name of the file.  The
+.I jobs
+command was run to find out which command was suspended. At this time the
+.I fg
+command was typed to continue execution of the mail program.  Input
+to the mail program was then continued and ended with a ^D
+which indicated the end of the message at which time the mail
+program typed EOT.  The
+.I jobs
+command will show which commands are suspended.
+The ^Z should only be typed at the beginning of a line since
+everything typed on the current line is discarded when a signal is sent
+from the keyboard.  This also happens on \s-2INTERRUPT\s0, and \s-2QUIT\s0
+signals.  More information on
+suspending jobs and controlling them is given in
+section 2.6.
+.PP
+If you write or run programs which are not fully debugged then it may
+be necessary to stop them somewhat ungracefully.
+This can be done by sending them a \s-2QUIT\s0
+signal, sent by typing a ^\e.
+This will usually provoke the shell to produce a message like:
+.DS
+Quit (Core dumped)
+.DE
+indicating that a file
+`core' has been created containing information about the running program's
+state when it terminated due to the \s-2QUIT\s0 signal.
+You can examine this file yourself, or forward information to the
+maintainer of the program telling him/her where the
+.I "core file"
+is.
+.PP
+If you run background commands (as explained in section 2.6) then these
+commands will ignore \s-2INTERRUPT\s0 and \s-2QUIT\s0 signals at the
+terminal.  To stop them you must use the
+.I kill
+command.  See section 2.6 for an example.
+.PP
+If you want to examine the output of a command without having it move
+off the screen as the output of the
+.DS
+cat /etc/passwd
+.DE
+command will, you can use the command
+.DS
+more /etc/passwd
+.DE
+The
+.I more
+program pauses after each complete screenful and types `\-\-More\-\-'
+at which point you can hit a space to get another screenful, a return
+to get another line, a `?' to get some help on other commands, or a `q' to end the
+.I more
+program.  You can also use more as a filter, i.e.
+.DS
+cat /etc/passwd | more
+.DE
+works just like the more simple more command above.
+.PP
+For stopping output of commands not involving
+.I more
+you can use the
+^S key to stop the typeout.  The typeout will resume when you
+hit ^Q or any other key, but ^Q is normally used because
+it only restarts the output and does not become input to the program
+which is running.  This works well on low-speed terminals, but at 9600
+baud it is hard to type ^S and ^Q fast enough to paginate
+the output nicely, and a program like
+.I more
+is usually used.
+.PP
+An additional possibility is to use the ^O flush output
+character; when this character is typed, all output from the current
+command is thrown away (quickly) until the next input read occurs
+or until the next shell prompt.  This can be used to allow a command
+to complete without having to suffer through the output on a slow
+terminal; ^O is a toggle, so flushing can be turned off by
+typing ^O again while output is being flushed.
+.NH 2
+What now?
+.PP
+We have so far seen a number of mechanisms of the shell and learned a lot
+about the way in which it operates.
+The remaining sections will go yet further into the internals of the
+shell, but you will surely want to try using the
+shell before you go any further.
+To try it you can log in to \s-2UNIX\s0 and type the following
+command to the system:
+.DS
+chsh myname /bin/csh
+.DE
+Here `myname' should be replaced by the name you typed to
+the system prompt of `login:' to get onto the system.
+Thus I would use `chsh bill /bin/csh'.
+.B
+You only have to do this once; it takes effect at next login.
+.R
+You are now ready to try using
+.I csh.
+.PP
+Before you do the `chsh' command, the shell you are using when
+you log into the system is `/bin/sh'.
+In fact, much of the above discussion is applicable to `/bin/sh'.
+The next section will introduce many features particular to
+.I csh
+so you should change your shell to
+.I csh
+before you begin reading it.
+.bp
diff --git a/bin/csh/USD.doc/csh.2 b/bin/csh/USD.doc/csh.2
new file mode 100644
index 0000000..610105c
--- /dev/null
+++ b/bin/csh/USD.doc/csh.2
@@ -0,0 +1,1305 @@
+.\" Copyright (c) 1980, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)csh.2	8.1 (Berkeley) 6/8/93
+.\"
+.nr H1 1
+.NH
+Details on the shell for terminal users
+.NH 2
+Shell startup and termination
+.PP
+When you login, the shell is started by the system in your
+.I home
+directory and begins by reading commands from a file
+.I \&.cshrc
+in this directory.
+All shells which you may start during your terminal session will
+read from this file.
+We will later see what kinds of commands are usefully placed there.
+For now we need not have this file and the shell does not complain about
+its absence.
+.PP
+A 
+.I "login shell" ,
+executed after you login to the system,
+will, after it reads commands from
+.I \&.cshrc,
+read commands from a file
+.I \&.login
+also in your home directory.
+This file contains commands which you wish to do each time you login
+to the \s-2UNIX\s0 system.
+My
+.I \&.login
+file looks something like:
+.DS
+set ignoreeof
+set mail=(/usr/spool/mail/bill)
+echo "${prompt}users" ; users
+alias ts \e
+	\'set noglob ; eval \`tset \-s \-m dialup:c100rv4pna \-m plugboard:?hp2621nl \!*\`\';
+ts; stty intr ^C kill ^U crt
+set time=15 history=10
+msgs \-f
+if (\-e $mail) then
+	echo "${prompt}mail"
+	mail
+endif
+.DE
+.PP
+This file contains several commands to be executed by \s-2UNIX\s0
+each time I login.
+The first is a
+.I set
+command which is interpreted directly by the shell.  It sets the shell
+variable
+.I ignoreeof
+which causes the shell to not log me off if I hit ^D.  Rather,
+I use the
+.I logout
+command to log off of the system.
+By setting the
+.I mail
+variable, I ask the shell to watch for incoming mail to me.  Every 5 minutes
+the shell looks for this file and tells me if more mail has arrived there.
+An alternative to this is to put the command
+.DS
+biff y
+.DE
+in place of this
+.I set;
+this will cause me to be notified immediately when mail arrives, and to
+be shown the first few lines of the new message.
+.PP
+Next I set the shell variable `time' to `15' causing the shell to automatically
+print out statistics lines for commands which execute for at least 15 seconds
+of \s-2CPU\s+2 time.  The variable `history' is set to 10 indicating that
+I want the shell to remember the last 10 commands I type in its
+.I "history list" ,
+(described later).
+.PP
+I create an
+.I alias
+``ts'' which executes a
+\fItset\fR\|(1) command setting up the modes of the terminal.
+The parameters to
+.I tset
+indicate the kinds of terminal which I usually use when not on a hardwired
+port.  I then execute ``ts'' and also use the
+.I stty
+command to change the interrupt character to ^C and the line kill
+character to ^U.
+.PP
+I then run the `msgs' program, which provides me with any
+system messages which I have not seen before; the `\-f' option here prevents
+it from telling me anything if there are no new messages.
+Finally, if my mailbox file exists, then I run the `mail' program to
+process my mail.
+.PP
+When the `mail' and `msgs' programs finish, the shell will finish
+processing my
+.I \&.login
+file and begin reading commands from the terminal, prompting for each with
+`% '.
+When I log off (by giving the 
+.I logout
+command) the shell
+will print `logout' and execute commands from the file `.logout'
+if it exists in my home directory.
+After that the shell will terminate and \s-2UNIX\s0 will log
+me off the system.
+If the system is not going down, I will receive a new login message.
+In any case, after the `logout' message the shell is committed to terminating
+and will take no further input from my terminal.
+.NH 2
+Shell variables
+.PP
+The shell maintains a set of
+.I variables.
+We saw above the variables
+.I history
+and
+.I time
+which had values `10' and `15'.
+In fact, each shell variable has as value an array of
+zero or more
+.I strings.
+Shell variables may be assigned values by the set command.  It has
+several forms, the most useful of which was given above and is
+.DS
+set name=value
+.DE
+.PP
+Shell variables may be used to store values which are to
+be used in commands later through a substitution mechanism.
+The shell variables most commonly referenced are, however, those which the
+shell itself refers to.
+By changing the values of these variables one can directly affect the
+behavior of the shell.
+.PP
+One of the most important variables is the variable
+.I path.
+This variable contains a sequence of directory names where the shell
+searches for commands.
+The
+.I set
+command with no arguments
+shows the value of all variables currently defined (we usually say
+.I set)
+in the shell.
+The default value for path will be shown by
+.I set
+to be
+.DS
+% set
+.ta .75i
+argv	()
+cwd	/usr/bill
+home	/usr/bill
+path	(. /usr/ucb /bin /usr/bin)
+prompt	%
+shell	/bin/csh
+status	0
+term	c100rv4pna
+user	bill
+%
+.so tabs
+.DE
+This output indicates that the variable path points to the current
+directory `.' and then `/usr/ucb', `/bin' and `/usr/bin'.
+Commands which you may write might be in `.' (usually one of
+your directories).
+Commands developed at Berkeley, live in `/usr/ucb'
+while commands developed at Bell Laboratories live in `/bin' and `/usr/bin'.
+.PP
+A number of locally developed programs on the system live in the directory
+`/usr/local'.
+If we wish that all shells which we invoke to have
+access to these new programs we can place the command
+.DS
+set path=(. /usr/ucb /bin /usr/bin /usr/local)
+.DE
+in our file
+.I \&.cshrc
+in our home directory.
+Try doing this and then logging out and back in and do
+.DS
+set
+.DE
+again to see that the value assigned to
+.I path
+has changed.
+.FS \(dg
+Another directory that might interest you is /usr/new, which contains
+many useful user-contributed programs provided with Berkeley Unix.
+.FE
+.PP
+One thing you should be aware of is that the shell examines each directory
+which you insert into your path and determines which commands are contained
+there.  Except for the current directory `.', which the shell treats specially,
+this means that if commands are added to a directory in your search path after
+you have started the shell, they will not necessarily be found by the shell.
+If you wish to use a command which has been added in this way, you should
+give the command
+.DS
+rehash
+.DE
+to the shell, which will cause it to recompute its internal table of command
+locations, so that it will find the newly added command.
+Since the shell has to look in the current directory `.' on each command,
+placing it at the end of the path specification usually works equivalently
+and reduces overhead.
+.PP
+Other useful built in variables are the variable
+.I home
+which shows your home directory,
+.I cwd
+which contains your current working directory,
+the variable
+.I ignoreeof
+which can be set in your
+.I \&.login
+file to tell the shell not to exit when it receives an end-of-file from
+a terminal (as described above).
+The variable `ignoreeof'
+is one of several variables which the shell does not care about the
+value of, only whether they are
+.I set
+or
+.I unset.
+Thus to set this variable you simply do
+.DS
+set ignoreeof
+.DE
+and to unset it do
+.DS
+unset ignoreeof
+.DE
+These give the variable `ignoreeof' no value, but none is desired or required.
+.PP
+Finally, some other built-in shell variables of use are the
+variables
+.I noclobber
+and
+.I mail.
+The metasyntax
+.DS
+> filename
+.DE
+which redirects the standard output of a command
+will overwrite and destroy the previous contents of the named file.
+In this way you may accidentally overwrite a file which is valuable.
+If you would prefer that the shell not overwrite files in this
+way you can
+.DS
+set noclobber
+.DE
+in your
+.I \&.login
+file.
+Then trying to do
+.DS
+date > now
+.DE
+would cause a diagnostic if `now' existed already.
+You could type
+.DS
+date >!  now
+.DE
+if you really wanted to overwrite the contents of `now'.
+The `>!' is a special metasyntax indicating that clobbering the
+file is ok.\(dg
+.FS
+\(dgThe space between the `!' and the word `now' is critical here, as `!now'
+would be an invocation of the
+.I history
+mechanism, and have a totally different effect.
+.FE
+.NH 2
+The shell's history list
+.PP
+The shell can maintain a
+.I "history list"
+into which it places the words
+of previous commands.
+It is possible to use a notation to reuse commands or words
+from commands in forming new commands.
+This mechanism can be used to repeat previous commands or to
+correct minor typing mistakes in commands.
+.PP
+The following figure gives a sample session involving typical usage of the
+history mechanism of the shell.
+.KF
+.DS
+% cat bug.c
+main()
+
+{
+	printf("hello);
+}
+% cc !$
+cc bug.c 
+"bug.c", line 4: newline in string or char constant
+"bug.c", line 5: syntax error
+% ed !$
+ed bug.c 
+29
+4s/);/"&/p
+        printf("hello");
+w
+30
+q
+% !c
+cc bug.c 
+% a.out
+hello% !e
+ed bug.c 
+30
+4s/lo/lo\e\en/p
+        printf("hello\en");
+w
+32
+q
+% !c \-o bug
+cc bug.c \-o bug
+% size a.out bug
+a.out: 2784+364+1028 = 4176b = 0x1050b
+bug: 2784+364+1028 = 4176b = 0x1050b
+% ls \-l !*
+ls \-l a.out bug 
+\(mirwxr\(mixr\(mix 1 bill       3932 Dec 19 09:41 a.out
+\(mirwxr\(mixr\(mix 1 bill       3932 Dec 19 09:42 bug
+% bug
+hello
+% num bug.c | spp
+spp: Command not found.
+% ^spp^ssp
+num bug.c | ssp 
+    1	main()
+    3	{
+    4		printf("hello\en");
+    5	}
+% !! | lpr
+num bug.c | ssp | lpr
+% 
+.DE
+.KE
+In this example we have a very simple C program which has a bug (or two)
+in it in the file `bug.c', which we `cat' out on our terminal.  We then
+try to run the C compiler on it, referring to the file again as `!$',
+meaning the last argument to the previous command.  Here the `!' is the
+history mechanism invocation metacharacter, and the `$' stands for the last
+argument, by analogy to `$' in the editor which stands for the end of the line.
+The shell echoed the command, as it would have been typed without use of
+the history mechanism, and then executed it.
+The compilation yielded error diagnostics so we now run the editor on the
+file we were trying to compile, fix the bug, and run the C compiler again,
+this time referring to this command simply as `!c', which repeats the last
+command which started with the letter `c'.  If there were other
+commands starting with `c' done recently we could have said `!cc' or even
+`!cc:p' which would have printed the last command starting with `cc'
+without executing it.
+.PP
+After this recompilation, we ran the resulting `a.out' file, and then
+noting that there still was a bug, ran the editor again.  After fixing
+the program we ran the C compiler again, but tacked onto the command
+an extra `\-o bug' telling the compiler to place the resultant binary in
+the file `bug' rather than `a.out'.  In general, the history mechanisms
+may be used anywhere in the formation of new commands and other characters
+may be placed before and after the substituted commands.
+.PP
+We then ran the `size' command to see how large the binary program images
+we have created were, and then an `ls \-l' command with the same argument
+list, denoting the argument list `\!*'.
+Finally we ran the program `bug' to see that its output is indeed correct.
+.PP
+To make a numbered listing of the program we ran the `num' command on the file `bug.c'.
+In order to compress out blank lines in the output of `num' we ran the
+output through the filter `ssp', but misspelled it as spp.  To correct this
+we used a shell substitute, placing the old text and new text between `^'
+characters.  This is similar to the substitute command in the editor.
+Finally, we repeated the same command with `!!', but sent its output to the
+line printer.
+.PP
+There are other mechanisms available for repeating commands.  The
+.I history
+command prints out a number of previous commands with numbers by which
+they can be referenced.  There is a way to refer to a previous command
+by searching for a string which appeared in it, and there are other,
+less useful, ways to select arguments to include in a new command.
+A complete description of all these mechanisms
+is given in the C shell manual pages in the \s-2UNIX\s0 Programmer's Manual.
+.NH 2
+Aliases
+.PP
+The shell has an
+.I alias
+mechanism which can be used to make transformations on input commands.
+This mechanism can be used to simplify the commands you type,
+to supply default arguments to commands,
+or to perform transformations on commands and their arguments.
+The alias facility is similar to a macro facility.
+Some of the features obtained by aliasing can be obtained also
+using shell command files, but these take place in another instance
+of the shell and cannot directly affect the current shells environment
+or involve commands such as
+.I cd
+which must be done in the current shell.
+.PP
+As an example, suppose that there is a new version of the mail program
+on the system called `newmail'
+you wish to use, rather than the standard mail program which is called
+`mail'.
+If you place the shell command
+.DS
+alias mail newmail
+.DE
+in your
+.I \&.cshrc
+file, the shell will transform an input line of the form
+.DS
+mail bill
+.DE
+into a call on `newmail'.
+More generally, suppose we wish the command `ls' to always show
+sizes of files, that is to always do `\-s'.
+We can do
+.DS
+alias ls ls \-s
+.DE
+or even
+.DS
+alias dir ls \-s
+.DE
+creating a new command syntax `dir'
+which does an `ls \-s'.
+If we say
+.DS
+dir ~bill
+.DE
+then the shell will translate this to
+.DS
+ls \-s /mnt/bill
+.DE
+.PP
+Thus the
+.I alias
+mechanism can be used to provide short names for commands,
+to provide default arguments,
+and to define new short commands in terms of other commands.
+It is also possible to define aliases which contain multiple
+commands or pipelines, showing where the arguments to the original
+command are to be substituted using the facilities of the
+history mechanism.
+Thus the definition
+.DS
+alias cd \'cd \e!* ; ls \'
+.DE
+would do an
+.I ls
+command after each change directory
+.I cd
+command.
+We enclosed the entire alias definition in `\'' characters to prevent
+most substitutions from occurring and the character `;' from being
+recognized as a metacharacter.
+The `!' here is escaped with a `\e' to prevent it from being interpreted
+when the alias command is typed in.
+The `\e!*' here substitutes the entire argument list to the pre-aliasing
+.I cd
+command, without giving an error if there were no arguments.
+The `;' separating commands is used here
+to indicate that one command is to be done and then the next.
+Similarly the definition
+.DS
+alias whois \'grep \e!^ /etc/passwd\'
+.DE
+defines a command which looks up its first argument in the password file.
+.PP
+.B Warning:
+The shell currently reads the
+.I \&.cshrc
+file each time it starts up.  If you place a large number of commands
+there, shells will tend to start slowly.  A mechanism for saving the shell
+environment after reading the \fI\&.cshrc\fR file and quickly restoring it is
+under development, but for now you should try to limit the number of
+aliases you have to a reasonable number... 10 or 15 is reasonable,
+50 or 60 will cause a noticeable delay in starting up shells, and make
+the system seem sluggish when you execute commands from within the editor
+and other programs.
+.NH 2
+More redirection; >> and >&
+.PP
+There are a few more notations useful to the terminal user
+which have not been introduced yet.
+.PP
+In addition to the standard output, commands also have a
+.I "diagnostic output"
+which is normally directed to the terminal even when the standard output
+is redirected to a file or a pipe.
+It is occasionally desirable to direct the diagnostic output along with
+the standard output.
+For instance if you want to redirect the output of a long running command
+into a file and wish to have a record of any error diagnostic it produces
+you can do
+.DS
+command >& file
+.DE
+The `>&' here tells the shell to route both the diagnostic output and the
+standard output into `file'.
+Similarly you can give the command
+.DS
+command |\|& lpr
+.DE
+to route both standard and diagnostic output through the pipe
+to the line printer daemon
+.I lpr.\(dd
+.FS
+\(dd A command of the form
+.br
+.ti +5
+command >&! file
+.br
+exists, and is used when
+.I noclobber
+is set and
+.I file
+already exists.
+.FE
+.PP
+Finally, it is possible to use the form
+.DS
+command >> file
+.DE
+to place output at the end of an existing file.\(dg
+.FS
+\(dg If
+.I noclobber
+is set, then an error will result if
+.I file
+does not exist, otherwise the shell will create
+.I file
+if it doesn't exist.
+A form
+.br
+.ti +5
+command >>! file
+.br
+makes it not be an error for file to not exist when
+.I noclobber
+is set.
+.FE
+.NH 2
+Jobs; Background, Foreground, or Suspended
+.PP
+When one or more commands
+are typed together as a pipeline or as a sequence of commands separated by
+semicolons, a single
+.I job
+is created by the shell consisting of these commands together as a unit.
+Single commands without pipes or semicolons create the simplest jobs.
+Usually, every line typed to the shell creates a job.
+Some lines that create jobs (one per line) are
+.DS
+sort < data
+ls \-s | sort \-n | head \-5
+mail harold
+.DE
+.PP
+If the metacharacter `&' is typed
+at the end of the commands, then the job is started as a
+.I background
+job.  This means that the shell does not wait for it to complete but
+immediately prompts and is ready for another command.  The job runs
+.I "in the background"
+at the same time that normal jobs, called
+.I foreground
+jobs, continue to be read and executed by the shell one at a time.
+Thus
+.DS
+du > usage &
+.DE
+would run the
+.I du
+program, which reports on the disk usage of your working directory (as well as
+any directories below it), put the output into the file `usage' and return
+immediately with a prompt for the next command without out waiting for
+.I du
+to finish.  The
+.I du
+program would continue executing in the background
+until it finished, even though you can type and execute more commands in the
+mean time.
+When a background
+job terminates, a message is typed by the shell just before the next prompt
+telling you that the job has completed.
+In the following example the
+.I du
+job finishes sometime during the
+execution of the
+.I mail
+command and its completion is reported just before
+the prompt after the
+.I mail
+job is finished.
+.DS
+% du > usage &
+[1] 503
+% mail bill
+How do you know when a background job is finished?
+EOT
+.ta 1.75i
+[1] \- Done	du > usage
+%
+.so tabs
+.DE
+If the job did not terminate normally the `Done' message might say
+something else like `Killed'.
+If you want the 
+terminations of background jobs to be reported at the time they occur
+(possibly interrupting the output of other foreground jobs), you can set
+the
+.I notify
+variable.  In the previous example this would mean that the
+`Done' message might have come right in the middle of the message to
+Bill.
+Background jobs are unaffected by any signals from the keyboard like
+the \s-2STOP\s0, \s-2INTERRUPT\s0, or \s-2QUIT\s0 signals mentioned earlier.
+.PP
+Jobs are recorded in a table inside the shell until they terminate.
+In this table, the shell remembers the command names, arguments and the
+.I "process numbers"
+of all commands in the job as well as the working directory where the job was
+started.
+Each job in the table is either running
+.I "in the foreground"
+with the shell waiting for it to terminate, running
+.I "in the background,"
+or
+.I suspended.
+Only one job can be running in the foreground at one time, but several
+jobs can be suspended or running in the background at once.  As each job
+is started, it is assigned a small identifying
+number called the
+.I "job number"
+which can be used later to refer to the job in the commands described below.
+Job numbers remain
+the same until the job terminates and then are re-used.
+.PP
+When a job is started in the backgound using `&', its number, as well
+as the process numbers of all its (top level) commands, is typed by the shell
+before prompting you for another command. For example,
+.DS
+% ls \-s | sort \-n > usage &
+[2] 2034 2035
+%
+.DE
+runs the `ls' program with the `\-s' options, pipes this output into
+the `sort' program with the `\-n' option which puts its output into the
+file `usage'.
+Since the `&' was at the end of the line, these two programs were started
+together as a background job.  After starting the job, the shell prints
+the job number in brackets (2 in this case) followed by the process number
+of each program started in the job.  Then the shell immediates prompts for
+a new command, leaving the job running simultaneously.
+.PP
+As mentioned in section 1.8, foreground jobs become
+.I suspended
+by typing ^Z
+which sends a \s-2STOP\s0 signal to the currently running
+foreground job.  A background job can become suspended by using the
+.I stop
+command described below.  When jobs are suspended they merely stop
+any further progress until started again, either in the foreground
+or the backgound.  The shell notices when a job becomes stopped and
+reports this fact, much like it reports the termination of background jobs.
+For foreground jobs this looks like
+.DS
+% du > usage
+^Z
+Stopped
+%
+.DE
+`Stopped' message is typed by the shell when it notices that the
+.I du
+program stopped.
+For background jobs, using the
+.I stop
+command, it is
+.DS
+% sort usage &
+[1] 2345
+% stop %1
+.ta 1.75i
+[1] + Stopped (signal)	sort usage
+%
+.so tabs
+.DE
+Suspending foreground jobs can be very useful when you need to temporarily
+change what you are doing (execute other commands) and then return to
+the suspended job.  Also, foreground jobs can be suspended and then
+continued as background jobs using the
+.I bg
+command, allowing you to continue other work and
+stop waiting for the foreground job to finish.  Thus
+.DS
+% du > usage
+^Z
+Stopped
+% bg
+[1] du > usage &
+%
+.DE
+starts `du' in the foreground, stops it before it finishes, then continues
+it in the background allowing more foreground commands to be executed.
+This is especially helpful
+when a foreground job ends up taking longer than you expected and you
+wish you had started it in the backgound in the beginning.
+.PP
+All
+.I "job control"
+commands can take an argument that identifies a particular
+job.
+All job name arguments begin with the character `%', since some of the
+job control commands also accept process numbers (printed by the
+.I ps
+command.)
+The default job (when no argument is given) is called the
+.I current
+job and is identified by a `+' in the output of the
+.I jobs
+command, which shows you which jobs you have.
+When only one job is stopped or running in the background (the usual case)
+it is always the current job thus no argument is needed.
+If a job is stopped while running in the foreground it becomes the
+.I current
+job and the existing current job becomes the
+.I previous
+job \- identified by a `\-' in the output of
+.I jobs.
+When the current job terminates, the previous job becomes the current job.
+When given, the argument is either `%\-' (indicating
+the previous job); `%#', where # is the job number; 
+`%pref' where pref is some unique prefix of the command name
+and arguments of one of the jobs; or `%?' followed by some string found
+in only one of the jobs.
+.PP
+The
+.I jobs
+command types the table of jobs, giving the job number,
+commands and status (`Stopped' or `Running') of each backgound or
+suspended job.  With the `\-l' option the process numbers are also
+typed.
+.DS
+% du > usage &
+[1] 3398
+% ls \-s | sort \-n > myfile &
+[2] 3405
+% mail bill
+^Z
+Stopped
+% jobs
+.ta 1.75i
+[1] \(mi Running	du > usage
+[2]    Running	ls \-s | sort \-n > myfile
+[3] \(pl Stopped	mail bill
+% fg %ls
+ls \-s | sort \-n > myfile
+% more myfile
+.so tabs
+.DE
+.PP
+The
+.I fg
+command runs a suspended or background job in the foreground.  It is
+used to restart a previously suspended job or change a background job
+to run in the foreground (allowing signals or input from the terminal).
+In the above example we used
+.I fg
+to change the `ls' job from the
+background to the foreground since we wanted to wait for it to
+finish before looking at its output file.
+The
+.I bg
+command runs a suspended job in the background.  It is usually used
+after stopping the currently running foreground job with the
+\s-2STOP\s0 signal.  The combination of the \s-2STOP\s0 signal and the
+.I bg
+command changes a foreground job into a background job.
+The
+.I stop
+command suspends a background job.
+.PP
+The
+.I kill
+command terminates a background or suspended job immediately.
+In addition to jobs, it may be given process numbers as arguments,
+as printed by
+.I ps.
+Thus, in the example above, the running
+.I du
+command could have been terminated by the command
+.DS
+% kill %1
+.ta 1.75i
+[1]  Terminated	du > usage
+%
+.so tabs
+.DE
+.PP
+The
+.I notify
+command (not the variable mentioned earlier) indicates that the termination
+of a specific job should be
+reported at the time it finishes instead of waiting for the next prompt.
+.PP
+If a job running in the background tries to read input from the terminal
+it is automatically stopped.  When such a job is then run in the
+foreground, input can be given to the job.  If desired, the job can
+be run in the background again until it requests input again.
+This is illustrated in the following sequence where the `s' command in the
+text editor might take a long time.
+.ID
+.nf
+% ed bigfile
+120000
+1,$s/thisword/thatword/
+^Z
+Stopped
+% bg
+[1] ed bigfile &
+% 
+ . . .  some foreground commands
+.ta 1.75i
+[1] Stopped (tty input)	ed bigfile
+% fg
+ed bigfile
+w
+120000
+q
+% 
+.so tabs
+.DE
+So after the `s' command was issued, the `ed' job was stopped with ^Z
+and then put in the background using
+.I bg.
+Some time later when the `s' command was finished,
+.I ed
+tried to read another command and was stopped because jobs
+in the backgound cannot read from the terminal.  The
+.I fg
+command returned the `ed' job to the foreground where it could once again
+accept commands from the terminal.
+.PP
+The command
+.DS
+stty tostop
+.DE
+causes all background jobs run on your terminal to stop
+when they are about to
+write output to the terminal.  This prevents messages from background
+jobs from interrupting foreground job output and allows you to run
+a job in the background without losing terminal output.  It also
+can be used for interactive programs that sometimes have long
+periods without interaction.  Thus each time it outputs a prompt for more
+input it will stop before the prompt.  It can then be run in the
+foreground using
+.I fg,
+more input can be given and, if necessary stopped and returned to
+the background.  This
+.I stty
+command might be a good thing to put in your
+.I \&.login
+file if you do not like output from background jobs interrupting
+your work.  It also can reduce the need for redirecting the output
+of background jobs if the output is not very big:
+.DS
+% stty tostop
+% wc hugefile &
+[1] 10387
+% ed text
+\&. . . some time later
+q
+.ta 1.75i
+[1] Stopped (tty output)	wc hugefile
+% fg wc
+wc hugefile
+   13371   30123   302577
+% stty \-tostop
+.so tabs
+.DE
+Thus after some time the `wc' command, which counts the lines, words
+and characters in a file, had one line of output.  When it tried to
+write this to the terminal it stopped.  By restarting it in the
+foreground we allowed it to write on the terminal exactly when we were
+ready to look at its output.
+Programs which attempt to change the mode of the terminal will also
+block, whether or not
+.I tostop
+is set, when they are not in the foreground, as
+it would be very unpleasant to have a background job change the state
+of the terminal.
+.PP
+Since the
+.I jobs
+command only prints jobs started in the currently executing shell,
+it knows nothing about background jobs started in other login sessions
+or within shell files.  The
+.I ps
+can be used in this case to find out about background jobs not started
+in the current shell.
+.NH 2
+Working Directories
+.PP
+As mentioned in section 1.6, the shell is always in a particular
+.I "working directory."
+The `change directory' command
+.I chdir
+(its
+short form
+.I cd
+may also be used)
+changes the working directory of the shell,
+that is, changes the directory you
+are located in.
+.PP
+It is useful to make a directory for each project you wish to work on
+and to place all files related to that project in that directory.
+The `make directory' command,
+.I mkdir,
+creates a new directory.
+The
+.I pwd
+(`print working directory') command
+reports the absolute pathname of the working directory of the shell,
+that is, the directory you are
+located in.
+Thus in the example below:
+.DS
+% pwd
+/usr/bill
+% mkdir newpaper
+% chdir newpaper
+% pwd
+/usr/bill/newpaper
+%
+.DE
+the user has created and moved to the
+directory
+.I newpaper.
+where, for example, he might
+place a group of related files.
+.PP
+No matter where you have moved to in a directory hierarchy,
+you can return to your `home' login directory by doing just
+.DS
+cd
+.DE
+with no arguments.
+The name `..' always means the directory above the current one in
+the hierarchy, thus
+.DS
+cd ..
+.DE
+changes the shell's working directory to the one directly above the
+current one.
+The name `..' can be used in any
+pathname, thus,
+.DS
+cd ../programs
+.DE
+means
+change to the directory `programs' contained in the directory
+above the current one.
+If you have several directories for different
+projects under, say, your home directory,
+this shorthand notation
+permits you to switch easily between them.
+.PP
+The shell always remembers the pathname of its current working directory in
+the variable
+.I cwd.
+The shell can also be requested to remember the previous directory when
+you change to a new working directory.  If the `push directory' command
+.I pushd
+is used in place of the
+.I cd
+command, the shell saves the name of the current working directory
+on a
+.I "directory stack"
+before changing to the new one.
+You can see this list at any time by typing the `directories'
+command
+.I dirs.
+.ID
+.nf
+% pushd newpaper/references
+~/newpaper/references  ~
+% pushd /usr/lib/tmac
+/usr/lib/tmac  ~/newpaper/references  ~
+% dirs
+/usr/lib/tmac  ~/newpaper/references  ~
+% popd
+~/newpaper/references  ~
+% popd
+~
+%
+.DE
+The list is printed in a horizontal line, reading left to right,
+with a tilde (~) as
+shorthand for your home directory\(emin this case `/usr/bill'.
+The directory stack is printed whenever there is more than one
+entry on it and it changes.
+It is also printed by a
+.I dirs
+command.
+.I Dirs
+is usually faster and more informative than
+.I pwd
+since it shows the current working directory as well as any
+other directories remembered in the stack.
+.PP
+The
+.I pushd
+command with no argument
+alternates the current directory with the first directory in the
+list.
+The `pop directory'
+.I popd
+command without an argument returns you to the directory you were in prior to
+the current one, discarding the previous current directory from the
+stack (forgetting it).
+Typing
+.I popd
+several times in a series takes you backward through the directories
+you had been in (changed to) by
+.I pushd
+command.
+There are other options to
+.I pushd
+and
+.I popd
+to manipulate the contents of the directory stack and to change
+to directories not at the top of the stack; see the
+.I csh
+manual page for details.
+.PP
+Since the shell remembers the working directory in which each job
+was started, it warns you when you might be confused by restarting
+a job in the foreground which has a different working directory than the
+current working directory of the shell.  Thus if you start a background
+job, then change the shell's working directory and then cause the
+background job to run in the foreground, the shell warns you that the
+working directory of the currently running foreground job is different
+from that of the shell.
+.DS
+% dirs \-l
+/mnt/bill
+% cd myproject
+% dirs
+~/myproject
+% ed prog.c
+1143
+^Z
+Stopped
+% cd ..
+% ls
+myproject
+textfile
+% fg
+ed prog.c (wd: ~/myproject)
+.DE
+This way the shell warns you when there
+is an implied change of working directory, even though no cd command was
+issued.  In the above example the `ed' job was still in `/mnt/bill/project'
+even though the shell had changed to `/mnt/bill'.
+A similar warning is given when such a foreground job
+terminates or is suspended (using the \s-2STOP\s0 signal) since
+the return to the shell again implies a change of working directory.
+.DS
+% fg
+ed prog.c (wd: ~/myproject)
+ . . . after some editing
+q
+(wd now: ~)
+%
+.DE
+These messages are sometimes confusing if you use programs that change
+their own working directories, since the shell only remembers which
+directory a job is started in, and assumes it stays there.
+The `\-l' option of
+.I jobs
+will type the working directory
+of suspended or background jobs when it is different
+from the current working directory of the shell.
+.NH 2
+Useful built-in commands
+.PP
+We now give a few of the useful built-in commands of the shell describing
+how they are used.
+.PP
+The
+.I alias
+command described above is used to assign new aliases and to show the
+existing aliases.
+With no arguments it prints the current aliases.
+It may also be given only one argument such as
+.DS
+alias ls
+.DE
+to show the current alias for, e.g., `ls'.
+.PP
+The
+.I echo
+command prints its arguments.
+It is often used in
+.I "shell scripts"
+or as an interactive command
+to see what filename expansions will produce.
+.PP
+The
+.I history
+command will show the contents of the history list.
+The numbers given with the history events can be used to reference
+previous events which are difficult to reference using the
+contextual mechanisms introduced above.
+There is also a shell variable called
+.I prompt.
+By placing a `!' character in its value the shell will there substitute
+the number of the current command in the history list.
+You can use this number to refer to this command in a history substitution.
+Thus you could
+.DS
+set prompt=\'\e! % \'
+.DE
+Note that the `!' character had to be
+.I escaped
+here even within `\'' characters.
+.PP
+The
+.I limit
+command is used to restrict use of resources.
+With no arguments it prints the current limitations:
+.DS
+.ta 1i
+cputime	unlimited
+filesize	unlimited
+datasize	5616 kbytes
+stacksize	512 kbytes
+coredumpsize	unlimited
+.so tabs
+.DE
+Limits can be set, e.g.:
+.DS
+limit coredumpsize 128k
+.DE
+Most reasonable units abbreviations will work; see the
+.I csh
+manual page for more details.
+.PP
+The
+.I logout
+command can be used to terminate a login shell which has
+.I ignoreeof
+set.
+.PP
+The
+.I rehash
+command causes the shell to recompute a table of where commands are
+located.  This is necessary if you add a command to a directory
+in the current shell's search path and wish the shell to find it,
+since otherwise the hashing algorithm may tell the shell that the
+command wasn't in that directory when the hash table was computed.
+.PP
+The
+.I repeat
+command can be used to repeat a command several times.
+Thus to make 5 copies of the file
+.I one
+in the file
+.I five
+you could do
+.DS
+repeat 5 cat one >> five
+.DE
+.PP
+The
+.I setenv
+command can be used
+to set variables in the environment.
+Thus
+.DS
+setenv TERM adm3a
+.DE
+will set the value of the environment variable \s-2TERM\s0
+to
+`adm3a'.
+A user program
+.I printenv
+exists which will print out the environment.
+It might then show:
+.DS
+% printenv
+HOME=/usr/bill
+SHELL=/bin/csh
+PATH=:/usr/ucb:/bin:/usr/bin:/usr/local
+TERM=adm3a
+USER=bill
+%
+.DE
+.PP
+The
+.I source
+command can be used to force the current shell to read commands from
+a file.
+Thus
+.DS
+source .cshrc
+.DE
+can be used after editing in a change to the
+.I \&.cshrc
+file which you wish to take effect right away.
+.PP
+The
+.I time
+command can be used to cause a command to be timed no matter how much
+\s-2CPU\s0 time it takes.
+Thus
+.DS
+% time cp /etc/rc /usr/bill/rc
+0.0u 0.1s 0:01 8% 2+1k 3+2io 1pf+0w
+% time wc /etc/rc /usr/bill/rc
+     52    178   1347 /etc/rc
+     52    178   1347 /usr/bill/rc
+    104    356   2694 total
+0.1u 0.1s 0:00 13% 3+3k 5+3io 7pf+0w
+%
+.DE
+indicates that the
+.I cp
+command used a negligible amount of user time (u)
+and about 1/10th of a system time (s); the elapsed time was 1 second (0:01),
+there was an average memory usage of 2k bytes of program space and 1k
+bytes of data space over the cpu time involved (2+1k); the program
+did three disk reads and two disk writes (3+2io), and took one page fault
+and was not swapped (1pf+0w).
+The word count command
+.I wc
+on the other hand used 0.1 seconds of user time and 0.1 seconds of system
+time in less than a second of elapsed time.
+The percentage `13%' indicates that over the period when it was active
+the command `wc' used an average of 13 percent of the available \s-2CPU\s0
+cycles of the machine.
+.PP
+The
+.I unalias
+and
+.I unset
+commands can be used
+to remove aliases and variable definitions from the shell, and
+.I unsetenv
+removes variables from the environment.
+.NH 2
+What else?
+.PP
+This concludes the basic discussion of the shell for terminal users.
+There are more features of the shell to be discussed here, and all
+features of the shell are discussed in its manual pages.
+One useful feature which is discussed later is the
+.I foreach
+built-in command which can be used to run the same command
+sequence with a number of different arguments.
+.PP
+If you intend to use \s-2UNIX\s0 a lot you you should look through
+the rest of this document and the csh manual pages (section1) to become familiar
+with the other facilities which are available to you.
+.bp
diff --git a/bin/csh/USD.doc/csh.3 b/bin/csh/USD.doc/csh.3
new file mode 100644
index 0000000..cf8af73
--- /dev/null
+++ b/bin/csh/USD.doc/csh.3
@@ -0,0 +1,650 @@
+.\" Copyright (c) 1980, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)csh.3	8.1 (Berkeley) 6/8/93
+.\"
+.nr H1 2
+.NH
+Shell control structures and command scripts
+.NH 2
+Introduction
+.PP
+It is possible to place commands in files and to cause shells to be
+invoked to read and execute commands from these files,
+which are called
+.I "shell scripts."
+We here detail those features of the shell useful to the writers of such
+scripts.
+.NH 2
+Make
+.PP
+It is important to first note what shell scripts are
+.I not
+useful for.
+There is a program called
+.I make
+which is very useful for maintaining a group of related files
+or performing sets of operations on related files.
+For instance a large program consisting of one or more files
+can have its dependencies described in a
+.I makefile
+which contains definitions of the commands used to create these
+different files when changes occur.
+Definitions of the means for printing listings, cleaning up the directory
+in which the files reside, and installing the resultant programs
+are easily, and most appropriately placed in this
+.I makefile.
+This format is superior and preferable to maintaining a group of shell
+procedures to maintain these files.
+.PP
+Similarly when working on a document a
+.I makefile
+may be created which defines how different versions of the document
+are to be created and which options of
+.I nroff
+or
+.I troff
+are appropriate.
+.NH 2
+Invocation and the argv variable
+.PP
+A
+.I csh
+command script may be interpreted by saying
+.DS
+% csh script ...
+.DE
+where
+.I script
+is the name of the file containing a group of
+.I csh
+commands and
+`\&...' is replaced by a sequence of arguments.
+The shell places these arguments in the variable
+.I argv
+and then begins to read commands from the script.
+These parameters are then available through the same mechanisms
+which are used to reference any other shell variables.
+.PP
+If you make the file
+`script'
+executable by doing
+.DS
+chmod 755 script
+.DE
+and place a shell comment at the beginning of the shell script
+(i.e. begin the file with a `#' character)
+then a `/bin/csh' will automatically be invoked to execute `script' when
+you type
+.DS
+script
+.DE
+If the file does not begin with a `#' then the standard shell
+`/bin/sh' will be used to execute it.
+This allows you to convert your older shell scripts to use
+.I csh
+at your convenience.
+.NH 2
+Variable substitution
+.PP
+After each input line is broken into words and history substitutions
+are done on it, the input line is parsed into distinct commands.
+Before each command is executed a mechanism know as
+.I "variable substitution"
+is done on these words.
+Keyed by the character `$' this substitution replaces the names
+of variables by their values.
+Thus
+.DS
+echo $argv
+.DE
+when placed in a command script would cause the current value of the
+variable
+.I argv
+to be echoed to the output of the shell script.
+It is an error for
+.I argv
+to be unset at this point.
+.PP
+A number of notations are provided for accessing components and attributes
+of variables.
+The notation
+.DS
+$?name
+.DE
+expands to `1' if name is
+.I set
+or to `0'
+if name is not
+.I set.
+It is the fundamental mechanism used for checking whether particular
+variables have been assigned values.
+All other forms of reference to undefined variables cause errors.
+.PP
+The notation
+.DS
+$#name
+.DE
+expands to the number of elements in the variable
+.I name.
+Thus
+.DS
+% set argv=(a b c)
+% echo $?argv
+1
+% echo $#argv
+3
+% unset argv
+% echo $?argv
+0
+% echo $argv
+Undefined variable: argv.
+%
+.DE
+.PP
+It is also possible to access the components of a variable
+which has several values.
+Thus
+.DS
+$argv[1]
+.DE
+gives the first component of
+.I argv
+or in the example above `a'.
+Similarly
+.DS
+$argv[$#argv]
+.DE
+would give `c',
+and
+.DS
+$argv[1\-2]
+.DE
+would give `a b'. Other notations useful in shell scripts are
+.DS
+$\fIn\fR
+.DE
+where
+.I n
+is an integer as a shorthand for
+.DS
+$argv[\fIn\fR\|]
+.DE
+the
+.I n\|th
+parameter and
+.DS
+$*
+.DE
+which is a shorthand for
+.DS
+$argv
+.DE
+The form
+.DS
+$$
+.DE
+expands to the process number of the current shell.
+Since this process number is unique in the system it can
+be used in generation of unique temporary file names.
+The form
+.DS
+$<
+.DE
+is quite special and is replaced by the next line of input read from
+the shell's standard input (not the script it is reading).  This is
+useful for writing shell scripts that are interactive, reading
+commands from the terminal, or even writing a shell script that
+acts as a filter, reading lines from its input file. Thus the sequence
+.DS
+echo 'yes or no?\ec'
+set a=($<)
+.DE
+would write out the prompt `yes or no?' without a newline and then
+read the answer into the variable `a'.  In this case `$#a' would be
+`0' if either a blank line or end-of-file (^D) was typed.
+.PP
+One minor difference between `$\fIn\fR\|' and `$argv[\fIn\fR\|]'
+should be noted here.
+The form
+`$argv[\fIn\fR\|]'
+will yield an error if
+.I n
+is not in the range
+`1\-$#argv'
+while `$n'
+will never yield an out of range subscript error.
+This is for compatibility with the way older shells handled parameters.
+.PP
+Another important point is that it is never an error to give a subrange
+of the form `n\-'; if there are less than
+.I n
+components of the given variable then no words are substituted.
+A range of the form `m\-n' likewise returns an empty vector without giving
+an error when \fIm\fR exceeds the number of elements of the given variable,
+provided the subscript \fIn\fR is in range.
+.NH 2
+Expressions
+.PP
+In order for interesting shell scripts to be constructed it
+must be possible to evaluate expressions in the shell based on the
+values of variables.
+In fact, all the arithmetic operations of the language C are available
+in the shell
+with the same precedence that they have in C.
+In particular, the operations `==' and `!=' compare strings
+and the operators `&&' and `|\|\||' implement the boolean and/or operations.
+The special operators `=~' and `!~' are similar to `==' and `!=' except
+that the string on the right side can have pattern matching characters
+(like *, ? or []) and the test is whether the string on the left matches
+the pattern on the right.
+.PP
+The shell also allows file enquiries of the form
+.DS
+\-? filename
+.DE
+where `?' is replace by a number of single characters.
+For instance the expression primitive
+.DS
+\-e filename
+.DE
+tell whether the file
+`filename'
+exists.
+Other primitives test for read, write and execute access to the file,
+whether it is a directory, or has non-zero length.
+.PP
+It is possible to test whether a command terminates normally,
+by a primitive of the
+form `{ command }' which returns true, i.e. `1' if the command
+succeeds exiting normally with exit status 0, or `0' if the command
+terminates abnormally or with exit status non-zero.
+If more detailed information about the execution status of a command
+is required, it can be executed and the variable `$status' examined
+in the next command.
+Since `$status' is set by every command, it is very transient.
+It can be saved if it is inconvenient to use it only in the single
+immediately following command.
+.PP
+For a full list of expression components available see the manual
+section for the shell.
+.NH 2
+Sample shell script
+.PP
+A sample shell script which makes use of the expression mechanism
+of the shell and some of its control structure follows:
+.DS
+% cat copyc
+#
+# Copyc copies those C programs in the specified list
+# to the directory ~/backup if they differ from the files
+# already in ~/backup
+#
+set noglob
+foreach i ($argv) 
+
+        if ($i !~ *.c) continue  # not a .c file so do nothing
+
+        if (! \-r ~/backup/$i:t) then
+                echo $i:t not in backup... not cp\e\'ed
+                continue
+        endif
+
+        cmp \-s $i ~/backup/$i:t # to set $status
+
+        if ($status != 0) then
+                echo new backup of $i
+                cp $i ~/backup/$i:t
+        endif
+end
+.DE
+.PP
+This script makes use of the
+.I foreach
+command, which causes the shell to execute the commands between the
+.I foreach
+and the matching
+.I end
+for each of the values given between `(' and `)' with the named
+variable, in this case `i' set to successive values in the list.
+Within this loop we may use the command
+.I break
+to stop executing the loop 
+and
+.I continue
+to prematurely terminate one iteration
+and begin the next.
+After the
+.I foreach
+loop the iteration variable
+(\fIi\fR in this case)
+has the value at the last iteration.
+.PP
+We set the variable
+.I noglob
+here to prevent filename expansion of the members of
+.I argv.
+This is a good idea, in general, if the arguments to a shell script
+are filenames which have already been expanded or if the arguments
+may contain filename expansion metacharacters.
+It is also possible to quote each use of a `$' variable expansion,
+but this is harder and less reliable.
+.PP
+The other control construct used here is a statement of the form
+.DS
+\fBif\fR ( expression ) \fBthen\fR
+	command
+	...
+\fBendif\fR
+.DE
+The placement of the keywords here is
+.B not
+flexible due to the current implementation of the shell.\(dg
+.FS
+\(dgThe following two formats are not currently acceptable to the shell:
+.sp
+.in +5
+.nf
+\fBif\fR ( expression )		# \fBWon't work!\fR
+\fBthen\fR
+	command
+	...
+\fBendif\fR
+.fi
+.in -5
+.sp
+and
+.sp
+.in +5
+.nf
+\fBif\fR ( expression ) \fBthen\fR command \fBendif\fR		# \fBWon't work\fR
+.in -5
+.fi
+.FE
+.PP
+The shell does have another form of the if statement of the form
+.DS
+\fBif\fR ( expression ) \fBcommand\fR
+.DE
+which can be written
+.DS
+\fBif\fR ( expression ) \e
+	command
+.DE
+Here we have escaped the newline for the sake of appearance.
+The command must not involve `\||\|', `&' or `;'
+and must not be another control command.
+The second form requires the final `\e' to
+.B immediately
+precede the end-of-line.
+.PP
+The more general
+.I if
+statements above also admit a sequence of
+.I else\-if
+pairs followed by a single
+.I else
+and an
+.I endif,
+e.g.:
+.DS
+\fBif\fR ( expression ) \fBthen\fR
+	commands
+\fBelse\fR \fBif\fR (expression ) \fBthen\fR
+	commands
+\&...
+
+\fBelse\fR
+	commands
+\fBendif\fR
+.DE
+.PP
+Another important mechanism used in shell scripts is the `:' modifier.
+We can use the modifier `:r' here to extract a root of a filename or
+`:e' to extract the
+.I extension.
+Thus if the variable
+.I i
+has the value
+`/mnt/foo.bar'
+then
+.sp
+.in +5
+.nf
+% echo $i $i:r $i:e
+/mnt/foo.bar /mnt/foo bar
+%
+.sp
+.in -5
+.fi
+shows how the `:r' modifier strips off the trailing `.bar' and the
+the `:e' modifier leaves only the `bar'.
+Other modifiers will take off the last component of a pathname leaving
+the head `:h' or all but the last component of a pathname leaving the
+tail `:t'.
+These modifiers are fully described in the
+.I csh
+manual pages in the User's Reference Manual.
+It is also possible to use the
+.I "command substitution"
+mechanism described in the next major section to perform modifications
+on strings to then reenter the shell's environment.
+Since each usage of this mechanism involves the creation of a new process,
+it is much more expensive to use than the `:' modification mechanism.\(dd
+.FS
+\(dd It is also important to note that
+the current implementation of the shell limits the number of `:' modifiers
+on a `$' substitution to 1.
+Thus
+.sp
+.nf
+.in +5
+% echo $i $i:h:t
+/a/b/c /a/b:t
+%
+.in -5
+.fi
+.sp
+does not do what one would expect.
+.FE
+Finally, we note that the character `#' lexically introduces a shell
+comment in shell scripts (but not from the terminal).
+All subsequent characters on the input line after a `#' are discarded
+by the shell.
+This character can be quoted using `\'' or `\e' to place it in
+an argument word.
+.NH 2
+Other control structures
+.PP
+The shell also has control structures
+.I while
+and
+.I switch
+similar to those of C.
+These take the forms
+.DS
+\fBwhile\fR ( expression )
+	commands
+\fBend\fR
+.DE
+and
+.DS
+\fBswitch\fR ( word )
+
+\fBcase\fR str1:
+	commands
+	\fBbreaksw\fR
+
+\& ...
+
+\fBcase\fR strn:
+	commands
+	\fBbreaksw\fR
+
+\fBdefault:\fR
+	commands
+	\fBbreaksw\fR
+
+\fBendsw\fR
+.DE
+For details see the manual section for
+.I csh.
+C programmers should note that we use
+.I breaksw
+to exit from a
+.I switch
+while
+.I break
+exits a
+.I while
+or
+.I foreach
+loop.
+A common mistake to make in
+.I csh
+scripts is to use
+.I break
+rather than
+.I breaksw
+in switches.
+.PP
+Finally,
+.I csh
+allows a
+.I goto
+statement, with labels looking like they do in C, i.e.:
+.DS
+loop:
+	commands
+	\fBgoto\fR loop
+.DE
+.NH 2
+Supplying input to commands
+.PP
+Commands run from shell scripts receive by default the standard
+input of the shell which is running the script.
+This is different from previous shells running
+under \s-2UNIX\s0.  It allows shell scripts to fully participate
+in pipelines, but mandates extra notation for commands which are to take
+inline data.
+.PP
+Thus we need a metanotation for supplying inline data to commands in
+shell scripts.
+As an example, consider this script which runs the editor to
+delete leading blanks from the lines in each argument file:
+.DS
+% cat deblank
+# deblank \-\- remove leading blanks
+foreach i ($argv)
+ed \- $i << \'EOF\'
+1,$s/^[ ]*//
+w
+q
+\&\'EOF\'
+end
+%
+.DE
+The notation `<< \'EOF\''
+means that the standard input for the
+.I ed
+command is to come from the text in the shell script file
+up to the next line consisting of exactly `\'EOF\''.
+The fact that the `EOF' is enclosed in `\'' characters, i.e. quoted,
+causes the shell to not perform variable substitution on the
+intervening lines.
+In general, if any part of the word following the `<<' which the
+shell uses to terminate the text to be given to the command is quoted
+then these substitutions will not be performed.
+In this case since we used the form `1,$' in our editor script
+we needed to insure that this `$' was not variable substituted.
+We could also have insured this by preceding the `$' here with a `\e',
+i.e.:
+.DS
+1,\e$s/^[ ]*//
+.DE
+but quoting the `EOF' terminator is a more reliable way of achieving the
+same thing.
+.NH 2
+Catching interrupts
+.PP
+If our shell script creates temporary files, we may wish to catch
+interruptions of the shell script so that we can clean up
+these files.
+We can then do
+.DS
+onintr label
+.DE
+where
+.I label
+is a label in our program.
+If an interrupt is received the shell will do a
+`goto label'
+and we can remove the temporary files and then do an
+.I exit
+command (which is built in to the shell)
+to exit from the shell script.
+If we wish to exit with a non-zero status we can do
+.DS
+exit(1)
+.DE
+e.g. to exit with status `1'.
+.NH 2
+What else?
+.PP
+There are other features of the shell useful to writers of shell
+procedures.
+The
+.I verbose
+and
+.I echo
+options and the related
+.I \-v
+and
+.I \-x
+command line options can be used to help trace the actions of the shell.
+The
+.I \-n
+option causes the shell only to read commands and not to execute
+them and may sometimes be of use.
+.PP
+One other thing to note is that
+.I csh
+will not execute shell scripts which do not begin with the
+character `#', that is shell scripts that do not begin with a comment.
+Similarly, the `/bin/sh' on your system may well defer to `csh'
+to interpret shell scripts which begin with `#'.
+This allows shell scripts for both shells to live in harmony.
+.PP
+There is also another quotation mechanism using `"' which allows
+only some of the expansion mechanisms we have so far discussed to occur
+on the quoted string and serves to make this string into a single word
+as `\'' does.
+.bp
diff --git a/bin/csh/USD.doc/csh.4 b/bin/csh/USD.doc/csh.4
new file mode 100644
index 0000000..ee862df
--- /dev/null
+++ b/bin/csh/USD.doc/csh.4
@@ -0,0 +1,178 @@
+.\" Copyright (c) 1980, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)csh.4	8.1 (Berkeley) 6/8/93
+.\"
+.nr H1 3
+.NH
+Other, less commonly used, shell features
+.NH 2
+Loops at the terminal; variables as vectors
+.PP
+It is occasionally useful to use the
+.I foreach
+control structure at the terminal to aid in performing a number
+of similar commands.
+For instance, there were at one point three shells in use on the Cory \s-2UNIX\s0
+system at Cory Hall,
+`/bin/sh',
+`/bin/nsh',
+and
+`/bin/csh'.
+To count the number of persons using each shell one could have issued
+the commands
+.DS
+% grep \-c csh$ /etc/passwd
+27
+% grep \-c nsh$ /etc/passwd
+128
+% grep \-c \-v sh$ /etc/passwd
+430
+%
+.DE
+Since these commands are very similar we can use
+.I foreach
+to do this more easily.
+.DS
+% foreach i (\'sh$\' \'csh$\' \'\-v sh$\')
+? grep \-c $i /etc/passwd
+? end
+27
+128
+430
+%
+.DE
+Note here that the shell prompts for
+input with `? ' when reading the body of the loop.
+.PP
+Very useful with loops are variables which contain lists of filenames
+or other words.
+You can, for example, do
+.DS
+% set a=(\`ls\`)
+% echo $a
+csh.n csh.rm
+% ls
+csh.n
+csh.rm
+% echo $#a
+2
+%
+.DE
+The
+.I set
+command here gave the variable
+.I a
+a list of all the filenames in the current directory as value.
+We can then iterate over these names to perform any chosen function.
+.PP
+The output of a command within `\`' characters is converted by
+the shell to a list of words.
+You can also place the `\`' quoted string within `"' characters
+to take each (non-empty) line as a component of the variable;
+preventing the lines from being split into words at blanks and tabs.
+A modifier `:x' exists which can be used later to expand each component
+of the variable into another variable splitting it into separate words
+at embedded blanks and tabs.
+.NH 2
+Braces { ... } in argument expansion
+.PP
+Another form of filename expansion, alluded
+to before involves the characters `{' and `}'.
+These characters specify that the contained strings, separated by `,'
+are to be consecutively substituted into the containing characters
+and the results expanded left to right.
+Thus
+.DS
+A{str1,str2,...strn}B
+.DE
+expands to
+.DS
+Astr1B Astr2B ... AstrnB
+.DE
+This expansion occurs before the other filename expansions, and may
+be applied recursively (i.e. nested).
+The results of each expanded string are sorted separately, left
+to right order being preserved.
+The resulting filenames are not required to exist if no other expansion
+mechanisms are used.
+This means that this mechanism can be used to generate arguments which are
+not filenames, but which have common parts.
+.PP
+A typical use of this would be
+.DS
+mkdir ~/{hdrs,retrofit,csh}
+.DE
+to make subdirectories `hdrs', `retrofit' and `csh'
+in your home directory.
+This mechanism is most useful when the common prefix is longer
+than in this example, i.e.
+.DS
+chown root /usr/{ucb/{ex,edit},lib/{ex?.?*,how_ex}}
+.DE
+.NH 2
+Command substitution
+.PP
+A command enclosed in `\`' characters is replaced, just before
+filenames are expanded, by the output from that command.
+Thus it is possible to do
+.DS
+set pwd=\`pwd\`
+.DE
+to save the current directory in the variable
+.I pwd
+or to do
+.DS
+ex \`grep \-l TRACE *.c\`
+.DE
+to run the editor
+.I ex
+supplying as arguments those files whose names end in `.c'
+which have the string `TRACE' in them.*
+.FS
+*Command expansion also occurs in input redirected with `<<'
+and within `"' quotations.
+Refer to the shell manual section for full details.
+.FE
+.NH 2
+Other details not covered here
+.PP
+In particular circumstances it may be necessary to know the exact
+nature and order of different substitutions performed by the shell.
+The exact meaning of certain combinations of quotations is also
+occasionally important.
+These are detailed fully in its manual section.
+.PP
+The shell has a number of command line option flags mostly of use
+in writing \s-2UNIX\s0 programs,
+and debugging shell scripts.
+See the csh(1) manual section for a list of these options.
+.bp
diff --git a/bin/csh/USD.doc/csh.a b/bin/csh/USD.doc/csh.a
new file mode 100644
index 0000000..1026faf
--- /dev/null
+++ b/bin/csh/USD.doc/csh.a
@@ -0,0 +1,95 @@
+.\" Copyright (c) 1980, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)csh.a	8.1 (Berkeley) 6/8/93
+.\"
+.SH
+Appendix \- Special characters
+.LP
+The following table lists the special characters of
+.I csh
+and the \s-2UNIX\s0 system, giving for each the section(s) in which it
+is discussed.
+A number of these characters also have special meaning in expressions.
+See the
+.I csh
+manual section
+for a complete list.
+.ta .75i 1.5i 2.25i
+.LP
+Syntactic metacharacters
+.DS
+;	2.4	separates commands to be executed sequentially
+|	1.5	separates commands in a pipeline
+( )	2.2,3.6	brackets expressions and variable values
+&	2.5	follows commands to be executed without waiting for completion
+.DE
+.LP
+Filename metacharacters
+.DS
+/	1.6	separates components of a file's pathname
+\.	1.6	separates root parts of a file name from extensions
+?	1.6	expansion character matching any single character
+*	1.6	expansion character matching any sequence of characters
+[ ]	1.6	expansion sequence matching any single character from a set
+~	1.6	used at the beginning of a filename to indicate home directories
+{ }	4.2	used to specify groups of arguments with common parts
+.DE
+.LP
+Quotation metacharacters
+.DS
+\e	1.7	prevents meta-meaning of following single character
+\'	1.7	prevents meta-meaning of a group of characters
+"	4.3	like \', but allows variable and command expansion
+.DE
+.LP
+Input/output metacharacters
+.DS
+<	1.5	indicates redirected input
+>	1.3	indicates redirected output
+.DE
+.LP
+Expansion/substitution metacharacters
+.DS
+$	3.4	indicates variable substitution
+!	2.3	indicates history substitution
+:	3.6	precedes substitution modifiers
+^	2.3	used in special forms of history substitution
+\`	4.3	indicates command substitution
+.DE
+.LP
+Other metacharacters
+.DS
+#	1.3,3.6	begins scratch file names; indicates shell comments
+\-	1.2	prefixes option (flag) arguments to commands
+%	2.6	prefixes job name specifications
+.DE
+.bp
diff --git a/bin/csh/USD.doc/csh.g b/bin/csh/USD.doc/csh.g
new file mode 100644
index 0000000..0641769
--- /dev/null
+++ b/bin/csh/USD.doc/csh.g
@@ -0,0 +1,1721 @@
+.\" Copyright (c) 1980, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)csh.g	8.1 (Berkeley) 6/8/93
+.\"
+.SH
+Glossary
+.PP
+This glossary lists the most important terms introduced in the
+introduction to the
+shell and gives references to sections of the shell
+document for further information about them.
+References of the form
+`pr (1)'
+indicate that the command
+.I pr
+is in the \s-2UNIX\s0 User Reference manual in section 1.
+You can look at an online copy of its manual page by doing
+.DS
+man 1 pr
+.DE
+References of the form (2.5)
+indicate that more information can be found in section 2.5 of this
+manual.
+.IP \&\fB.\fR 15n
+Your current directory has the name `.' as well as the name printed
+by the command
+.I pwd;
+see also
+.I dirs.
+The current directory `.' is usually the first 
+.I component 
+of the search path contained in the variable
+.I path ,
+thus commands which are in `.' are found first (2.2).
+The character `.' is also used in separating 
+.I components 
+of filenames
+(1.6).
+The character `.' at the beginning of a 
+.I component 
+of a 
+.I pathname 
+is treated specially and not matched by the 
+.I "filename expansion"
+metacharacters `?', `*', and `[' `]' pairs (1.6).
+.IP \&\fB..\fR
+Each directory has a file `..' in it which is a reference to its
+parent directory.
+After changing into the directory with
+.I chdir ,
+i.e.
+.DS
+chdir paper
+.DE
+you can return to the parent directory by doing
+.DS
+chdir ..
+.DE
+The current directory is printed by
+.I pwd
+(2.7).
+.IP a.out
+Compilers which create executable images create them, by default, in the
+file 
+.I a.out.
+for historical reasons (2.3).
+.IP "absolute pathname"
+.br
+A 
+.I pathname 
+which begins with a `/' is
+.I absolute
+since it specifies the 
+.I path 
+of directories from the beginning
+of the entire directory system \- called the
+.I root
+directory.  
+.I Pathname s 
+which are not
+.I absolute
+are called
+.I relative
+(see definition of
+.I "relative pathname" )
+(1.6).
+.IP alias
+An
+.I alias
+specifies a shorter or different name for a \s-2UNIX\s0
+command, or a transformation on a command to be performed in
+the shell.
+The shell has a command
+.I alias
+which establishes 
+.I aliases 
+and can print their current values.
+The command
+.I unalias
+is used to remove 
+.I aliases 
+(2.4).
+.IP argument
+Commands in \s-2UNIX\s0 receive a list of 
+.I argument 
+words.
+Thus the command
+.DS
+echo a b c
+.DE
+consists of the
+.I "command name"
+`echo' and three 
+.I argument 
+words `a', `b' and `c'.
+The set of 
+.I arguments 
+after the
+.I "command name"
+is said to be the
+.I "argument list"
+of the command (1.1).
+.IP argv
+The list of arguments to a command written in the shell language
+(a shell script or shell procedure) is stored in a variable called
+.I argv
+within the shell.
+This name is taken from the conventional name in the
+C programming language (3.4).
+.IP background
+Commands started without waiting for them to complete are called
+.I background
+commands (2.6).
+.IP base
+A filename is sometimes thought of as consisting of a
+.I base
+part, before any `.' character, and an 
+.I extension 
+\- the part after
+the `.'.  See
+.I filename
+and
+.I extension
+(1.6) and basename (1).
+.IP bg
+The
+.I bg
+command causes a
+.I suspended 
+job to continue execution in the
+.I background
+(2.6).
+.IP bin
+A directory containing binaries of programs and shell scripts to be
+executed is typically called a 
+.I bin 
+directory.
+The standard system 
+.I bin 
+directories are `/bin' containing the most
+heavily used commands and `/usr/bin' which contains most other user
+programs.
+Programs developed at UC Berkeley live in `/usr/ucb', while locally
+written programs live in `/usr/local'.  Games are kept in the directory
+`/usr/games'.
+You can place binaries in any directory.
+If you wish to execute them often, the name of the directories
+should be a 
+.I component 
+of the variable
+.I path .
+.IP break
+.I Break
+is a builtin command used to exit from loops within the control
+structure of the shell (3.7).
+.IP breaksw
+The
+.I breaksw
+builtin command is used to exit from a
+.I switch
+control structure, like a
+.I break
+exits from loops (3.7).
+.IP builtin
+A command executed directly by the shell is called a
+.I builtin
+command.
+Most commands in \s-2UNIX\s0 are not built into the shell,
+but rather exist as files in 
+.I bin 
+directories.
+These commands are accessible because the directories in which
+they reside are named in the
+.I path
+variable.
+.IP case
+A
+.I case
+command is used as a label in a
+.I switch
+statement in the shell's control structure, similar to that of the
+language C.
+Details are given in the shell documentation `csh (1)' (3.7).
+.IP cat
+The
+.I cat
+program catenates a list of specified files on the 
+.I "standard output" .
+It is usually used to look at the contents of a single file on the terminal,
+to `cat a file' (1.8, 2.3).
+.IP cd
+The
+.I cd
+command is used to change the 
+.I "working directory" .
+With no arguments,
+.I cd
+changes your 
+.I "working directory" 
+to be your
+.I home
+directory (2.4, 2.7).
+.IP chdir
+The
+.I chdir
+command is a synonym for
+.I cd .
+.I Cd
+is usually used because it is easier to type.
+.IP chsh
+The
+.I chsh
+command is used to change the shell which you use on \s-2UNIX\s0.
+By default, you use an different version of the shell
+which resides in `/bin/sh'.
+You can change your shell to `/bin/csh' by doing
+.DS
+chsh your-login-name /bin/csh
+.DE
+Thus I would do
+.DS
+chsh bill /bin/csh
+.DE
+It is only necessary to do this once.
+The next time you log in to \s-2UNIX\s0 after doing this command,
+you will be using
+.I csh
+rather than the shell in `/bin/sh' (1.9).
+.IP cmp
+.I Cmp
+is a program which compares files.
+It is usually used on binary files, or to see if two files are identical (3.6).
+For comparing text files the program
+.I diff ,
+described in `diff (1)' is used.
+.IP command
+A function performed by the system, either by the shell
+(a builtin 
+.I command )
+or by a program residing in a file in
+a directory within the \s-2UNIX\s0 system, is called a
+.I command
+(1.1).
+.IP "command name"
+.br
+When a command is issued, it consists of a
+.I "command name" ,
+which is the first word of the command,
+followed by arguments.
+The convention on \s-2UNIX\s0 is that the first word of a
+command names the function to be performed (1.1).
+.IP "command substitution"
+.br
+The replacement of a command enclosed in `\`' characters
+by the text output by that command 
+is called
+.I "command substitution"
+(4.3).
+.IP component
+A part of a
+.I pathname
+between `/' characters is called a
+.I component
+of that 
+.I pathname .
+A variable
+which has multiple strings as value is said to have
+several
+.I component s;
+each string is a
+.I component
+of the variable.
+.IP continue
+A builtin command which causes execution of the enclosing
+.I foreach
+or
+.I while
+loop to cycle prematurely.
+Similar to the
+.I continue
+command in the programming language C (3.6).
+.IP control-
+Certain special characters, called
+.I control
+characters, are produced by holding down the \s-2CONTROL\s0 key
+on your terminal and simultaneously pressing another character, much like
+the \s-2SHIFT\s0 key is used to produce upper case characters. Thus
+.I control- c
+is produced by holding down the \s-2CONTROL\s0 key while pressing the
+`c' key.  Usually \s-2UNIX\s0 prints an caret (^) followed by the
+corresponding letter when you type a
+.I control
+character (e.g. `^C' for
+.I control- c
+(1.8).
+.IP "core\ dump"
+When a program terminates abnormally, the system places an image
+of its current state in a file named `core'.
+This 
+.I "core dump"
+can be examined with the system debugger `adb (1)'
+or `sdb (1)' in order to determine what went wrong with the program (1.8).
+If the shell produces a message of the form
+.DS
+Illegal instruction (core dumped)
+.DE
+(where `Illegal instruction' is only one of several possible
+messages), you should report this to the author of the program
+or a system administrator, 
+saving the `core' file.
+.IP cp
+The
+.I cp
+(copy) program is used to copy the contents of one file into another
+file.
+It is one of the most commonly used \s-2UNIX\s0 commands (1.6).
+.IP csh
+The name of the shell
+program that this document describes.
+.IP \&.cshrc
+The file
+.I \&.cshrc
+in your
+.I home
+directory is read by each shell as it begins execution.
+It is usually used to change the setting of the variable
+.I path
+and to set
+.I alias
+parameters which are to take effect globally (2.1).
+.IP cwd
+The
+.I cwd
+variable in the shell holds the
+.I "absolute pathname"
+of the current
+.I "working directory" \&.
+It is changed by the shell whenever your current
+.I "working directory"
+changes and should not be changed otherwise (2.2).
+.IP date
+The
+.I date
+command prints the current date and time (1.3).
+.IP debugging
+.I Debugging
+is the process of correcting mistakes in programs and shell scripts.
+The shell has several options and variables which may be used
+to aid in shell 
+.I debugging 
+(4.4).
+.IP default:
+The label
+.I default:
+is used within shell
+.I switch
+statements, as it is in the C language
+to label the code to be executed if none of the
+.I case
+labels matches the value switched on (3.7).
+.IP \s-2DELETE\s0
+The
+\s-2DELETE\s0
+or
+\s-2RUBOUT\s0
+key on the terminal normally causes an interrupt to be sent to the current job.
+Many users change the interrupt character to be ^C.
+.IP detached
+A command that continues running in the 
+.I background 
+after you logout is said to be 
+.I detached .
+.IP diagnostic
+An error message produced by a program is often referred to as a
+.I diagnostic .
+Most error messages are not written to the 
+.I "standard output" ,
+since that is often directed away from the terminal (1.3, 1.5).
+Error messsages are instead written to the
+.I "diagnostic output"
+which may be directed away from the terminal, but usually is not.
+Thus 
+.I diagnostics 
+will usually appear on the terminal (2.5).
+.IP directory
+A structure which contains files.
+At any time you are in one particular 
+.I directory 
+whose names can be printed by the command 
+.I pwd .
+The
+.I chdir
+command will change you to another 
+.I directory , 
+and make the files
+in that 
+.I directory 
+visible. The 
+.I directory 
+in which you are when you first login is your
+.I home
+directory (1.1, 2.7).
+.IP "directory\ stack"
+The shell saves the names of previous
+.I "working directories"
+in the
+.I "directory stack"
+when you change your current
+.I "working directory"
+via the
+.I pushd
+command.  The
+.I "directory stack"
+can be printed by using the
+.I dirs
+command, which includes your current
+.I "working directory"
+as the first directory name on the left (2.7).
+.IP dirs
+The
+.I dirs
+command prints the shell's
+.I "directory stack" 
+(2.7).
+.IP du
+The
+.I du
+command is a program (described in `du (1)') which
+prints the number of disk blocks is all directories below
+and including your current
+.I "working directory"
+(2.6).
+.IP echo
+The
+.I echo
+command prints its arguments (1.6, 3.6).
+.IP else
+The
+.I else
+command is part of the `if-then-else-endif' control
+command construct (3.6).
+.IP endif
+If an
+.I if
+statement is ended with the word
+.I then ,
+all lines following the
+.I if
+up to a line starting with the word
+.I endif
+or
+.I else
+are executed if the condition between parentheses after the
+.I if
+is true (3.6).
+.IP \s-2EOF\s0
+An
+.I "end\f1-\fPof\f1-\fPfile"
+is generated by the terminal by a control-d,
+and whenever a command reads to the end of a file which
+it has been given as input.
+Commands receiving input from a
+.I pipe
+receive an 
+.I "end\f1-\fPof\f1-\fPfile" 
+when the command sending them input completes.
+Most commands terminate when they receive an 
+.I "end\f1-\fPof\f1-\fPfile" .
+The shell has an option to ignore 
+.I "end\f1-\fPof\f1-\fPfile" 
+from a terminal
+input which may help you keep from logging out accidentally
+by typing too many control-d's (1.1, 1.8, 3.8).
+.IP escape
+A character `\e' used to prevent the special meaning of a metacharacter
+is said to
+.I escape
+the character from its special meaning.
+Thus
+.DS
+echo \e*
+.DE
+will echo the character `*' while just
+.DS
+echo *
+.DE
+will echo the names of the file in the current directory.
+In this example, \e
+.I escape s
+`*' (1.7).
+There is also a non-printing character called
+.I escape , 
+usually labelled
+\s-2ESC\s0
+or
+\s-2ALTMODE\s0
+on terminal keyboards.
+Some older \s-2UNIX\s0 systems use this character to indicate that
+output is to be 
+.I suspended . 
+Most systems use control-s to stop the output and control-q to start it.
+.IP /etc/passwd
+This file contains information about the accounts currently on the
+system.
+It consists of a line for each account with fields separated by
+`:' characters (1.8).
+You can look at this file by saying
+.DS
+cat /etc/passwd
+.DE
+The commands
+.I finger
+and
+.I grep
+are often used to search for information in this file.
+See `finger (1)', `passwd(5)', and `grep (1)' for more details.
+.IP exit
+The
+.I exit
+command is used to force termination of a shell script,
+and is built into the shell (3.9).
+.IP "exit\ status"
+A command which discovers a problem may reflect this back to the command
+(such as a shell) which invoked (executed) it.
+It does this by returning a non-zero number as its
+.I "exit status" ,
+a status of zero being considered
+`normal termination'.
+The
+.I exit
+command can be used to force a shell command script to give a non-zero
+.I "exit status" 
+(3.6).
+.IP expansion
+The replacement of strings in the shell input which contain metacharacters
+by other strings is referred to as the process of
+.I expansion .
+Thus the replacement of the word `*' by a sorted list of files
+in the current directory is a `filename expansion'.
+Similarly the replacement of the characters `!!' by the text of
+the last command is a `history expansion'.
+.I Expansions 
+are also referred to as
+.I substitutions
+(1.6, 3.4, 4.2).
+.IP expressions
+.I Expressions 
+are used in the shell
+to control the conditional structures used in the writing of shell
+scripts and in calculating values for these scripts.
+The operators available in shell 
+.I expressions 
+are those of the language
+C (3.5).
+.IP extension
+Filenames often consist of a
+.I base
+name and an
+.I extension
+separated by the character `.'.
+By convention, groups of related files often share the same 
+.I root 
+name.
+Thus if `prog.c' were a C program, then the object file for this
+program would be stored in `prog.o'.
+Similarly a paper written with the
+`\-me'
+nroff macro package might be stored in
+`paper.me'
+while a formatted version of this paper might be kept in
+`paper.out' and a list of spelling errors in
+`paper.errs' (1.6).
+.IP fg
+The
+.I "job control"
+command
+.I fg
+is used to run a
+.I background
+or
+.I suspended
+job in the
+.I foreground
+(1.8, 2.6).
+.IP filename
+Each file in \s-2UNIX\s0 has a name consisting of up to 14 characters
+and not including the character `/' which is used in
+.I pathname
+building.  Most 
+.I filenames
+do not begin with the character `.', and contain 
+only letters and digits with perhaps a `.' separating the
+.I base
+portion of the 
+.I filename 
+from an 
+.I extension 
+(1.6).
+.IP "filename expansion"
+.br
+.I "Filename expansion" 
+uses the metacharacters `*', `?' and `[' and `]'
+to provide a convenient mechanism for naming files.
+Using 
+.I "filename expansion" 
+it is easy to name all the files in
+the current directory, or all files which have a common 
+.I root 
+name. Other 
+.I "filename expansion" 
+mechanisms use the metacharacter `~' and allow
+files in other users' directories to be named easily (1.6, 4.2).
+.IP flag
+Many \s-2UNIX\s0 commands accept arguments which are not the names
+of files or other users but are used to modify the action of the commands.
+These are referred to as
+.I flag
+options, and by convention consist of one or more letters preceded by
+the character `\-' (1.2).
+Thus the
+.I ls
+(list files) command has an option
+`\-s' to list the sizes of files.
+This is specified
+.DS
+ls \-s
+.DE
+.IP foreach
+The
+.I foreach
+command is used in shell scripts and at the terminal to specify
+repetition of a sequence of commands while the value of a certain
+shell variable ranges through a specified list (3.6, 4.1).
+.IP foreground
+When commands are executing in the normal way such that the
+shell is waiting for them to finish before prompting for another
+command they are said to be
+.I "foreground jobs"
+or
+.I "running in the foreground" \&.  
+This is as opposed to
+.I background .
+.I Foreground
+jobs can be stopped by signals
+from the terminal caused by typing different
+control characters at the keyboard (1.8, 2.6).
+.IP goto
+The shell has a command
+.I goto
+used in shell scripts to transfer control to a given label (3.7).
+.IP grep
+The
+.I grep
+command searches through a list of argument files for a specified string.
+Thus
+.DS
+grep bill /etc/passwd
+.DE
+will print each line in the file
+.I "/etc/passwd"
+which contains the string `bill'.
+Actually,
+.I grep
+scans for 
+.I "regular expressions"
+in the sense of the editors
+`ed (1)' and `ex (1)'.
+.I Grep
+stands for
+`globally find 
+.I "regular expression" 
+and print' (2.4).
+.IP head
+The
+.I head
+command prints the first few lines of one or more files.
+If you have a bunch of files containing text which you are wondering
+about it is sometimes useful to run
+.I head
+with these files as arguments.
+This will usually show enough of what is in these files to let you decide
+which you are interested in (1.5).
+.br
+.I Head
+is also used to describe the part of a
+.I pathname
+before and including the last `/' character.  The
+.I tail
+of a
+.I pathname
+is the part after the last `/'.  The `:h' and `:t' modifiers allow the
+.I head
+or
+.I tail
+of a 
+.I pathname 
+stored in a shell variable to be used (3.6).
+.IP history
+The
+.I history
+mechanism of the shell allows previous commands to be repeated,
+possibly after modification to correct typing mistakes or to change
+the meaning of the command.
+The shell has a
+.I "history list"
+where these commands are kept, and a
+.I history
+variable which controls how large this list is (2.3).
+.IP "home\ directory"
+.br
+Each user has a 
+.I "home directory" ,
+which is given in your entry
+in the password file,
+.I /etc/passwd .
+This is the directory which you are placed in when you first login.
+The
+.I cd
+or
+.I chdir
+command with no arguments takes you back to this directory, whose
+name is recorded in the shell variable
+.I home .
+You can also access the 
+.I "home directories" 
+of other users in forming
+filenames using a 
+.I "filename expansion" 
+notation and the character `~' (1.6).
+.IP if
+A conditional command within the shell, the
+.I if
+command is used in shell command scripts to make decisions
+about what course of action to take next (3.6).
+.IP ignoreeof
+Normally, your shell will exit, printing
+`logout'
+if you type a control-d at a prompt of `% '.
+This is the way you usually log off the system.
+You can
+.I set
+the
+.I ignoreeof
+variable if you wish in your
+.I \&.login
+file and then use the command
+.I logout
+to logout.
+This is useful if you sometimes accidentally type too many control-d
+characters, logging yourself off
+(2.2).
+.IP input
+Many commands on \s-2UNIX\s0 take information from the terminal or from
+files which they then act on.
+This information is called
+.I input .
+Commands normally read for 
+.I input 
+from their
+.I "standard input"
+which is, by default, the terminal.
+This 
+.I "standard input" 
+can be redirected from a file using a shell metanotation
+with the character `<'.
+Many commands will also read from a file specified as argument.
+Commands placed in 
+.I pipelines
+will read from the output of the previous
+command in the 
+.I pipeline .
+The leftmost command in a 
+.I pipeline 
+reads from the terminal if
+you neither redirect its 
+.I input 
+nor give it a filename to use as
+.I "standard input" .
+Special mechanisms exist for supplying input to commands in shell
+scripts (1.5, 3.8).
+.IP interrupt
+An
+.I interrupt
+is a signal to a program that is generated by typing ^C. (On older versions
+of UNIX the \s-2RUBOUT\s0 or \s-2DELETE\s0 key were used for this purpose.)
+It causes most programs to stop execution.
+Certain programs, such as the shell and the editors,
+handle an 
+.I interrupt 
+in special ways, usually by stopping what they
+are doing and prompting for another command.
+While the shell is executing another command and waiting for it
+to finish, the shell does not listen to 
+.I interrupts.
+The shell often wakes up when you hit 
+.I interrupt 
+because many commands
+die when they receive an 
+.I interrupt 
+(1.8, 3.9).
+.IP job
+One or more commands
+typed on the same input line separated by `|' or `;' characters
+are run together and are called a
+.I job \&.
+Simple commands run by themselves without any `|' or `;' characters
+are the simplest 
+.I jobs.
+.I Jobs
+are classified as
+.I foreground ,
+.I background ,
+or
+.I suspended
+(2.6).
+.IP "job\ control"
+The builtin functions that control the execution of
+jobs are called
+.I "job control"
+commands.  These are
+.I "bg, fg, stop, kill"
+(2.6).
+.IP "job\ number"
+When each job
+is started it is assigned a small number called a
+.I "job number"
+which is printed next to the job in the output of the
+.I jobs
+command.  This number, preceded by a `%' character, can be used as an argument
+to
+.I "job control"
+commands to indicate
+a specific job (2.6).
+.IP jobs
+The
+.I jobs
+command prints a table showing
+jobs that are either running in the
+.I background
+or are
+.I suspended
+(2.6).
+.IP kill
+A command which sends a
+signal
+to a job causing it to terminate (2.6).
+.IP \&.login
+The file
+.I \&.login
+in your
+.I home
+directory is read by the shell each time you login to \s-2UNIX\s0
+and the commands there are executed.
+There are a number of commands which are usefully placed here,
+especially
+.I set
+commands to the shell itself (2.1).
+.IP "login\ shell"
+The shell that is started on your terminal when you login is called
+your
+.I "login shell" .
+It is different from other shells which you may run (e.g. on
+shell scripts)
+in that it reads the
+.I \&.login
+file before reading commands from the terminal and it reads the
+.I \&.logout
+file after you logout
+(2.1).
+.IP logout
+The
+.I logout
+command causes a login shell to exit.
+Normally, a login shell will exit when you hit control-d
+generating an 
+.I end\f1-\fPof\f1-\fPfile, 
+but if you have set
+.I ignoreeof
+in you
+.I \&.login
+file then this will not work and you must use
+.I logout
+to log off the \s-2UNIX\s0 system (2.8).
+.IP \&.logout
+When you log off of \s-2UNIX\s0 the shell will execute commands from
+the file
+.I \&.logout
+in your
+.I home
+directory after it prints `logout'.
+.IP lpr
+The command
+.I lpr
+is the line printer daemon.
+The standard input of
+.I lpr
+spooled and printed on the \s-2UNIX\s0 line printer.
+You can also give
+.I lpr
+a list of filenames as arguments to be printed.
+It is most common to use
+.I lpr
+as the last component of a
+.I pipeline
+(2.3).
+.IP ls
+The
+.I ls
+(list files) command is one of the most commonly used \s-2UNIX\s0
+commands.
+With no argument filenames it prints the names of the files in the
+current directory.
+It has a number of useful
+.I flag
+arguments, and can also be given the names of directories
+as arguments, in which case it lists the names of the files in these
+directories (1.2).
+.IP mail
+The
+.I mail
+program is used to send and receive messages from other \s-2UNIX\s0
+users (1.1, 2.1), whether they are logged on or not.
+.IP make
+The
+.I make
+command is used to maintain one or more related files and to
+organize functions to be performed on these files. 
+In many ways
+.I make
+is easier to use, and more helpful than
+shell command scripts (3.2).
+.IP makefile
+The file containing commands for
+.I make
+is called
+.I makefile 
+or 
+.I Makefile
+(3.2).
+.IP manual
+The 
+.I manual 
+often referred to is the
+`\s-2UNIX\s0 manual'.
+It contains 8 numbered sections with a description of each \s-2UNIX\s0
+program (section 1), system call (section 2), subroutine (section 3),
+device (section 4), special data structure (section 5), game (section 6),
+miscellaneous item (section 7) and system administration program (section 8).
+There are also supplementary documents (tutorials and reference guides)
+for individual programs which require explanation in more detail.
+An online version of the 
+.I manual 
+is accessible through the
+.I man
+command.
+Its documentation can be obtained online via
+.DS
+man man
+.DE
+If you can't decide what manual page to look in, try the 
+.I apropos (1)
+command.
+The supplementary documents are in subdirectories of /usr/doc.
+.IP metacharacter
+.br
+Many characters which are neither letters nor digits have special meaning
+either to the shell or to \s-2UNIX\s0.
+These characters are called
+.I metacharacters .
+If it is necessary to place these characters in arguments to commands
+without them having their special meaning then they must be
+.I quoted .
+An example of a 
+.I metacharacter 
+is the character `>' which is used
+to indicate placement of output into a file.
+For the purposes of the
+.I history
+mechanism,
+most unquoted 
+.I metacharacters
+form separate words (1.4).
+The appendix to this user's manual lists the 
+.I metacharacters
+in groups by their function.
+.IP mkdir
+The
+.I mkdir
+command is used to create a new directory.
+.IP modifier
+Substitutions with the 
+.I history 
+mechanism, keyed by the character `!'
+or of variables using the metacharacter `$', are often subjected
+to modifications, indicated by placing the character `:' after the
+substitution and following this with the 
+.I modifier 
+itself.
+The
+.I "command substitution"
+mechanism can also be used to perform modification in a similar way,
+but this notation is less clear (3.6).
+.IP more
+The program
+.I more
+writes a file on your terminal allowing you to control how much text
+is displayed at a time.
+.I More
+can move through the file screenful by screenful, line by line,
+search forward for a string, or start again at the beginning of the file.
+It is generally the easiest way of viewing a file (1.8).
+.IP noclobber
+The shell has a variable
+.I noclobber
+which may be set in the file
+.I \&.login
+to prevent accidental destruction of files by the `>' output redirection
+metasyntax of the shell (2.2, 2.5).
+.IP noglob
+The shell variable
+.I noglob
+is set to suppress the
+.I "filename expansion"
+of arguments containing the metacharacters `~', `*', `?', `[' and `]' (3.6).
+.IP notify
+The
+.I notify
+command tells the shell to report on the termination of a specific
+.I "background job"
+at the exact time it occurs as opposed to waiting
+until just before the next prompt to report the termination.
+The
+.I notify
+variable, if set, causes the shell to always report the termination
+of
+.I background 
+jobs exactly when they occur (2.6).
+.IP onintr
+The
+.I onintr
+command is built into the shell and is used to control the action
+of a shell command script when an 
+.I interrupt 
+signal is received (3.9).
+.IP output
+Many commands in \s-2UNIX\s0 result in some lines of text which are
+called their
+.I output.
+This 
+.I output 
+is usually placed on what is known as the
+.I "standard output"
+which is normally connected to the user's terminal.
+The shell has a syntax using the metacharacter `>' for redirecting
+the 
+.I "standard output" 
+of a command to a file (1.3).
+Using the
+.I pipe
+mechanism and the metacharacter `|' it is also possible for
+the 
+.I "standard output" 
+of one command to become the 
+.I "standard input" 
+of another command (1.5).
+Certain commands such as the line printer daemon
+.I p
+do not place their results on the 
+.I "standard output" 
+but rather in more
+useful places such as on the line printer (2.3).
+Similarly the
+.I write
+command places its output on another user's terminal rather than its
+.I "standard output" 
+(2.3).
+Commands also have a
+.I "diagnostic output"
+where they write their error messages.
+Normally these go to the terminal even if the 
+.I "standard output" 
+has been sent to a file or another command, but it is possible
+to direct error diagnostics along with 
+.I "standard output" 
+using a special metanotation (2.5).
+.IP path
+The shell has a variable
+.I path
+which gives the names of the directories in which it searches for
+the commands which it is given.
+It always checks first to see if the command it is given is
+built into the shell.
+If it is, then it need not search for the command as it can do it internally.
+If the command is not builtin, then the shell searches for a file
+with the name given in each of the directories in the
+.I path
+variable, left to right.
+Since the normal definition of the
+.I path
+variable is
+.DS
+path	(. /usr/ucb /bin /usr/bin)
+.DE
+the shell normally looks in the current directory, and then in
+the standard system directories `/usr/ucb', `/bin' and `/usr/bin' for the named
+command (2.2).
+If the command cannot be found the shell will print an error diagnostic.
+Scripts of shell commands will be executed using another shell to interpret
+them if they have `execute' permission set.
+This is normally true because a command of the form
+.DS
+chmod 755 script
+.DE
+was executed to turn this execute permission on (3.3).
+If you add new commands to a directory in the 
+.I path , 
+you should issue
+the command 
+.I rehash 
+(2.2).
+.IP pathname
+A list of names, separated by `/' characters, forms a
+.I pathname.
+Each
+.I component,
+between successive `/' characters, names a directory
+in which the next 
+.I component 
+file resides.
+.I Pathnames 
+which begin with the character `/' are interpreted relative
+to the
+.I root
+directory in the filesystem.
+Other 
+.I pathnames 
+are interpreted relative to the current directory
+as reported by
+.I pwd.
+The last component of a 
+.I pathname 
+may name a directory, but
+usually names a file.
+.IP pipeline
+A group of commands which are connected together, the 
+.I "standard output"
+of each connected to the 
+.I "standard input" 
+of the next,
+is called a
+.I pipeline.
+The
+.I pipe
+mechanism used to connect these commands is indicated by
+the shell metacharacter `|' (1.5, 2.3).
+.IP popd
+The
+.I popd
+command changes the shell's
+.I "working directory"
+to the directory you most recently left using the
+.I pushd
+command.  It returns to the directory without having to type its name,
+forgetting the name of the current
+.I "working directory"
+before doing so (2.7).
+.IP port
+The part of a computer system to which each terminal is
+connected is called a
+.I port .
+Usually the system has a fixed number of
+.I ports ,
+some of which are connected to telephone lines
+for dial-up access, and some of which are permanently
+wired directly to specific terminals.
+.IP pr
+The
+.I pr
+command is used to prepare listings of the contents of files
+with headers giving the name of the file and the date and
+time at which the file was last modified (2.3).
+.IP printenv
+The
+.I printenv
+command is used
+to print the current setting of variables in the environment
+(2.8).
+.IP process
+An instance of a running program is called a 
+.I process 
+(2.6).
+\s-2UNIX\s0 assigns each 
+.I process 
+a unique number when it is 
+started \- called the
+.I "process number" .
+.I "Process numbers" 
+can be used to stop individual 
+.I processes
+using the 
+.I kill
+or
+.I stop
+commands when the
+.I processes
+are part of a detached
+.I background
+job.
+.IP program
+Usually synonymous with
+.I command ;
+a binary file or shell command script
+which performs a useful function is often
+called a 
+.I program .
+.IP prompt
+Many programs will print a 
+.I prompt 
+on the terminal when they expect input.
+Thus the editor
+`ex (1)' will print a `:' when it expects input.
+The shell 
+.I prompts
+for input with `% ' and occasionally with `? ' when
+reading commands from the terminal (1.1).
+The shell has a variable
+.I prompt
+which may be set to a different value to change the shell's main 
+.I prompt .
+This is mostly used when debugging the shell (2.8).
+.IP pushd
+The
+.I pushd
+command, which means `push directory', changes the shell's
+.I "working directory"
+and also remembers the current
+.I "working directory"
+before the change is made, allowing you to return to the same
+directory via the
+.I popd
+command later without retyping its name (2.7).
+.IP ps
+The
+.I ps
+command is used to show the processes you are currently running.
+Each process is shown with its unique process number,
+an indication of the terminal name it is attached to,
+an indication of the state of the process (whether it is running,
+stopped, awaiting some event (sleeping), and whether it is swapped out),
+and the amount of \s-2CPU\s0 time it has used so far.
+The command is identified by printing some of the words used
+when it was invoked (2.6).
+Shells, such as the
+.I csh
+you use to run the 
+.I ps 
+command, are not normally shown in the output.
+.IP pwd
+The
+.I pwd
+command prints the full 
+.I pathname 
+of the current
+.I "working directory" \&.
+The
+.I dirs
+builtin command is usually a better and faster choice.
+.IP quit
+The
+.I quit
+signal, generated by a control-\e,
+is used to terminate programs which are behaving unreasonably.
+It normally produces a core image file (1.8).
+.IP quotation
+The process by which metacharacters are prevented their special
+meaning, usually by using the character `\' in pairs, or by
+using the character `\e', is referred to as
+.I quotation
+(1.7).
+.IP redirection
+The routing of input or output from or to a file is known
+as
+.I redirection
+of input or output (1.3).
+.IP rehash
+The
+.I rehash
+command tells the shell to rebuild its internal table of which commands
+are found in which directories in your
+.I path .
+This is necessary when a new program is installed in one of these
+directories (2.8).
+.IP "relative pathname"
+.br
+A
+.I pathname
+which does not begin with a `/' is called a
+.I "relative pathname"
+since it is interpreted
+.I relative
+to the current 
+.I "working directory" .
+The first
+.I component
+of such a
+.I pathname
+refers to some file or directory in the
+.I "working directory" ,
+and subsequent
+.I components
+between `/' characters refer to directories below the
+.I "working directory" .
+.I Pathnames
+that are not
+.I relative
+are called
+.I "absolute pathnames"
+(1.6).
+.IP repeat
+The
+.I repeat
+command iterates another command a specified number of times.
+.IP root
+The directory
+that is at the top of the entire directory structure is called the
+.I root
+directory since it is the `root' of the entire tree structure of
+directories.  The name used in
+.I pathnames
+to indicate the
+.I root
+is `/'.  
+.I Pathnames 
+starting with `/' are said to be
+.I absolute
+since they start at the
+.I root
+directory.
+.I Root
+is also used as the part of a 
+.I pathname 
+that is left after removing
+the 
+.I extension .
+See
+.I filename
+for a further explanation (1.6).
+.IP \s-2RUBOUT\s0
+The \s-2RUBOUT\s0 or \s-2DELETE\s0
+key is often used to erase the previously typed character; some users
+prefer the \s-2BACKSPACE\s0 for this purpose.  On older versions of \s-2UNIX\s0
+this key served as the \s-2INTR\s0 character.
+.IP "scratch file"
+Files whose names begin with a `#' are referred to as 
+.I "scratch files" ,
+since they are automatically removed by the system after a couple of
+days of non-use, or more frequently if disk space becomes tight (1.3).
+.IP script
+Sequences of shell commands placed in a file are called shell command 
+.I scripts .
+It is often possible to perform simple tasks using these 
+.I scripts 
+without writing a program in a language such as C, by
+using the shell to selectively run other programs (3.3, 3.10).
+.IP set
+The builtin
+.I set
+command is used to assign new values to shell variables
+and to show the values of the current variables.
+Many shell variables have special meaning to the shell itself.
+Thus by using the 
+.I set 
+command the behavior of the shell can be affected (2.1).
+.IP setenv
+Variables in the environment `environ (5)'
+can be changed by using the
+.I setenv
+builtin command (2.8).
+The
+.I printenv
+command can be used to print the value of the variables in the environment.
+.IP shell
+A 
+.I shell 
+is a command language interpreter.
+It is possible to write and run your own 
+.I shell ,
+as 
+.I shells 
+are no different than any other programs as far as the
+system is concerned.
+This manual deals with the details of one particular 
+.I shell ,
+called
+.I csh.
+.IP "shell script"
+See
+.I script
+(3.3, 3.10).
+.IP signal
+A
+.I signal
+in \s-2UNIX\s0 is a short message that is sent to a running program
+which causes something to happen to that process.
+.I Signals
+are sent either by typing special
+.I control
+characters on the keyboard or by using the
+.I kill
+or
+.I stop
+commands (1.8, 2.6).
+.IP sort
+The
+.I sort
+program sorts a sequence of lines in ways that can be controlled
+by argument 
+.I flags 
+(1.5).
+.IP source
+The
+.I source
+command causes the shell to read commands from a specified file.
+It is most useful for reading files such as
+.I \&.cshrc
+after changing them (2.8).
+.IP "special character"
+.br
+See
+.I metacharacters
+and the
+appendix to this manual.
+.IP standard
+We refer often to the
+.I "standard input"
+and
+.I "standard output"
+of commands.
+See
+.I input
+and
+.I output
+(1.3, 3.8).
+.IP status
+A command normally returns a
+.I status
+when it finishes.
+By convention a
+.I status
+of zero indicates that the command succeeded.
+Commands may return non-zero 
+.I status 
+to indicate that some abnormal event has occurred.
+The shell variable
+.I status
+is set to the 
+.I status 
+returned by the last command.
+It is most useful in shell commmand scripts (3.6).
+.IP stop
+The
+.I stop
+command causes a
+.I background 
+job to become 
+.I suspended 
+(2.6).
+.IP string
+A sequential group of characters taken together is called a
+.I string \&.
+.I Strings
+can contain any printable characters (2.2).
+.IP stty
+The
+.I stty
+program changes certain parameters inside \s-2UNIX\s0 which determine
+how your terminal is handled.  See `stty (1)' for a complete description (2.6).
+.IP substitution
+The shell implements a number of
+.I substitutions
+where sequences indicated by metacharacters are replaced by other sequences.
+Notable examples of this are history 
+.I substitution 
+keyed by the
+metacharacter `!' and variable 
+.I substitution 
+indicated by `$'.
+We also refer to 
+.I substitutions 
+as
+.I expansions
+(3.4).
+.IP suspended
+A job becomes
+.I suspended
+after a \s-2STOP\s0 signal is sent to it, either by typing a
+.I control -z
+at the terminal (for
+.I foreground
+jobs) or by using the
+.I stop
+command (for
+.I background
+jobs).  When
+.I suspended ,
+a job temporarily stops running until it is restarted by either the
+.I fg
+or
+.I bg
+command (2.6).
+.IP switch
+The
+.I switch
+command of the shell allows the shell
+to select one of a number of sequences of commands based on an
+argument string.
+It is similar to the
+.I switch
+statement in the language C (3.7).
+.IP termination
+When a command which is being executed finishes we say it undergoes
+.I termination
+or
+.I terminates.
+Commands normally terminate when they read an 
+.I end\f1-\fPof\f1-\fPfile
+from their 
+.I "standard input" .
+It is also possible to terminate commands by sending them
+an
+.I interrupt
+or
+.I quit
+signal (1.8).
+The
+.I kill
+program terminates specified jobs (2.6).
+.IP then
+The
+.I then
+command is part of the shell's
+`if-then-else-endif' control construct used in command scripts (3.6).
+.IP time
+The
+.I time
+command can be used to measure the amount of \s-2CPU\s0
+and real time consumed by a specified command as well
+as the amount of disk i/o, memory utilized, and number
+of page faults and swaps taken by the command (2.1, 2.8).
+.IP tset
+The
+.I tset
+program is used to set standard erase and kill characters
+and to tell the system what kind of terminal you are using.
+It is often invoked in a
+.I \&.login
+file (2.1).
+.IP tty
+The word
+.I tty
+is a historical abbreviation for `teletype' which is frequently used
+in \s-2UNIX\s0 to indicate the
+.I port
+to which a given terminal is connected.  The
+.I tty
+command will print the name of the
+.I tty
+or
+.I port
+to which your terminal is presently connected.
+.IP unalias
+The
+.I unalias
+command removes aliases (2.8).
+.IP \s-2UNIX\s0
+\s-2UNIX\s0 is an operating system on which
+.I csh
+runs.
+\s-2UNIX\s0 provides facilities which allow
+.I csh
+to invoke other programs such as editors and text formatters which
+you may wish to use.
+.IP unset
+The
+.I unset
+command removes the definitions of shell variables (2.2, 2.8).
+.IP "variable expansion"
+.br
+See
+.I variables
+and
+.I expansion
+(2.2, 3.4).
+.IP variables
+.I Variables 
+in
+.I csh
+hold one or more strings as value.
+The most common use of 
+.I variables 
+is in controlling the behavior
+of the shell.
+See
+.I path ,
+.I noclobber ,
+and
+.I ignoreeof
+for examples.
+.I Variables 
+such as
+.I argv
+are also used in writing shell programs (shell command scripts)
+(2.2).
+.IP verbose
+The
+.I verbose
+shell variable can be set to cause commands to be echoed
+after they are history expanded.
+This is often useful in debugging shell scripts.
+The
+.I verbose
+variable is set by the shell's
+.I \-v
+command line option (3.10).
+.IP wc
+The
+.I wc
+program calculates the number of characters, words, and lines in the
+files whose names are given as arguments (2.6).
+.IP while
+The
+.I while
+builtin control construct is used in shell command scripts (3.7).
+.IP word
+A sequence of characters which forms an argument to a command is called
+a
+.I word .
+Many characters which are neither letters, digits, `\-', `.' nor `/'
+form 
+.I words 
+all by themselves even if they are not surrounded
+by blanks.
+Any sequence of characters may be made into a 
+.I word 
+by surrounding it
+with `\'' characters
+except for the characters `\'' and `!' which require special treatment
+(1.1).
+This process of placing special characters in 
+.I words 
+without their special meaning is called
+.I quoting .
+.IP "working directory"
+.br
+At any given time you are in one particular directory, called
+your 
+.I "working directory" .
+This directory's name is printed by the
+.I pwd
+command and the files listed by
+.I ls
+are the ones in this directory.
+You can change 
+.I "working directories" 
+using
+.I chdir .
+.IP write
+The
+.I write
+command is an obsolete way of communicating with other users who are logged in to
+\s-2UNIX\s0 (you have to take turns typing).  If you are both using display 
+terminals, use \fItalk\fP(1), which is much more pleasant.
diff --git a/bin/csh/USD.doc/tabs b/bin/csh/USD.doc/tabs
new file mode 100644
index 0000000..9d274a1
--- /dev/null
+++ b/bin/csh/USD.doc/tabs
@@ -0,0 +1,34 @@
+.\" Copyright (c) 1980, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)tabs	8.1 (Berkeley) 6/8/93
+.\"
+.ta 5n 10n 15n 20n 25n 30n 35n 40n 45n 50n 55n 60n 65n 70n 75n 80n