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csh(1)								       csh(1)



NAME

  csh -	C shell	command	interpreter

SYNOPSIS

  csh [-bcefinstvVxX] [argument...]

  The csh command invokes the C	shell and interprets C shell commands.

OPTIONS

  -b  Forces a break from option processing, causing any further shell argu-
      ments to be treated as nonoption arguments.  This	can be used to pass
      options to a shell script	without	confusion or possible subterfuge.
      The shell	cannot run a set-user-ID script	without	this option.

  -c  Reads commands from the following	single argument, which must be
      present.	Any remaining arguments	are placed in argv.

  -e  Causes the shell to exit if any invoked command terminates abnormally
      or yields	a nonzero exit status.

  -f  Causes the shell to start	faster,	because	it neither searches for	nor
      executes the .cshrc file in the invoker's	home directory.

  -i  Causes the shell to be interactive, even if the input does not come
      from a terminal.	Shells are always interactive when invoked from	a
      terminal.

  -n  Parses commands, but does	not execute them. This aids in syntactic
      checking of shell	scripts.

  -s  Takes command input from the standard input.

  -t  Reads and	executes a single line of input. You can use a \ (backslash)
      to escape	the newline character at the end of the	current	line to	con-
      tinue onto another line.

  -v  Sets the verbose shell variable, with the	effect that command input is
      echoed to	the standard output after history substitution.

  -V  Sets the verbose shell variable, even before .cshrc is executed.

  -x  Sets the echo shell variable, so that commands are echoed	to the stan-
      dard error after all substitutions and immediately before	execution.

  -X  Sets the echo shell variable, even before	.cshrc is executed.

  After	processing of option arguments,	if arguments remain but	none of	the
  -c, -i, -s, or -t options was	given, the first argument is taken as the
  name of a file of commands to	be executed (that is, a	shell script). The
  shell	opens this file, and saves its name for	possible resubstitution	by
  $0.  If the first characters of the shell script are #!shell_pathname	or
  #csh,	csh runs the specified shell to	process	the script. Otherwise, csh
  runs.	 Remaining parameters initialize the argv variable.




DESCRIPTION

  The C	shell is an interactive	command	interpreter and	a command programming
  language that	uses a syntax similar to the C programming language.  The
  shell	carries	out commands either from a file	(called	a shell	script or
  procedure) or	interactively from a terminal keyboard.

  When you run csh, it begins by executing commands from the file .cshrc in
  your home directory, if it exists.  If the shell is invoked with a name
  that starts with -, as when started by login,	the shell runs as a login
  shell.  If csh runs as a login shell,	it executes commands from the
  system-wide login file /etc/csh.login, if that file exists, and then com-
  mands	from your $home/.cshrc file and	your $home/.login file,	in that
  order.  (If argument zero ($0) to the	shell is a - (dash), then the shell
  is a login shell.)  Your system administrator	can create /etc/csh.login to
  provide a standardized environment for all users, but	you can	include	com-
  mands	in $home/.cshrc	or $home/.login	to override settings and assignments
  made by /etc/csh.login.

  At log in, the $home shell variable and the $HOME environment	variable both
  refer	to your	home directory.	 If you	subsequently change $home to some
  other	value, you will	encounter problems because the shell will not be able
  to find files	it uses, such as .cshrc	and .bindings.

  In the normal	case, the shell	begins reading commands	from the terminal,
  prompting with % (percent sign) or # (number sign) for the superuser.	Pro-
  cessing of arguments and the use of the shell	to process files containing
  command scripts is described later.

  The shell then repeatedly performs the following actions:

   1.  A line of command input is read and broken into words.

   2.  This sequence of	words is placed	on the command history list and	then
       parsed.

   3.  Each command in the current line	is executed.

  When a login shell terminates, it executes commands from the file .logout
  in your home directory.

  Shell	Features


    +  Job control and status reporting

    +  File name completion

    +  History substitution

    +  Command aliasing

    +  Variable	substitution

    +  Command substitution

    +  File name substitution

    +  Input/output redirection	and control flow

    +  Built-in	commands





  Lexical Structure


  A simple command is a	sequence of words separated by spaces or tabs.	The
  shell	splits input lines into	words at spaces	and tabs with the following
  exceptions:

    +  The characters &&amp;, |, ;, <&lt;, >&gt;, (,	), and # form separate words. If dou-
       bled in &&amp;&&amp;, ||, <&lt;<&lt;, or >&gt;>&gt;, these	pairs form single words.

    +  Preceding parser	metacharacters with a \	(backslash) prevents the
       shell from interpreting them as special characters.  A newline pre-
       ceded by	a \ (backslash)	is equivalent to a space.

    +  Strings enclosed	in " " (double quotes),	` ` (grave accents), or	' '
       (single quotes) form parts of a word; metacharacters in these strings,
       including spaces	and tabs, do not form separate words.  For more
       information, see	the section Quoting with Single	and Double Quotes.
       Within pairs of ' or " characters, you can include the newline charac-
       ter by preceding	it with	a \ (backslash).

    +  When the	shell is not reading input from	a terminal, it treats any
       word that begins	with a # (number sign) character as a comment and
       ignores that word and all characters following up to the	next newline
       character. The #	character loses	its special meaning when it is quoted
       (preceded) by a \ (backslash) or	when the string	is enclosed in quotes
       using `,	', or ".

       When the	shell is reading input from a terminal without the c option,
       the # character is not treated specially.  However, when	reading	input
       from a terminal with the	c option, the shell treats a # character as
       the start of a comment and ignores subsequent text up to	the next new-
       line unless the # is quoted with	a \ (backslash)	or the string is
       enclosed	in quotes using	`, ', or ".

  Shell	Commands


  A simple command is a	sequence of words, the first of	which (numbered	0)
  specifies the	command	to be executed.	Any remaining words, with a few
  exceptions, are passed to that command.  If the command specifies an exe-
  cutable file that is a compiled program, the shell immediately runs that
  program.  If the file	is marked executable but is not	a compiled program,
  the shell assumes that it is a shell script.	In this	case, it starts
  another shell	to read	the file and execute the commands included in it.
  (See the section Nonbuilt-In Command Execution for information about using
  the $shell variable to determine which shell is executed.)

  A pipeline is	a sequence of one or more commands separated by	either the |
  (vertical bar) or |&&amp; (vertical bar and ampersand) characters.	With |,	the
  standard output of the preceding command is redirected to the	standard
  input	of the command that follows. With |&&amp;, both the standard	error and the
  standard output are redirected. Note that you	cannot pipe to a built-in
  command and an attempt to do so generates an error message. A	list is	a
  sequence of pipelines	separated by a ; (semicolon), &&amp;	(ampersand), &&amp;&&amp;	(two
  ampersands), or || (two vertical bars) and optionally	ended by a ; (semi-
  colon) or an &&amp; (ampersand).  These separators	and terminators	have the fol-
  lowing effects:

  ;   Causes sequential	execution of the preceding pipeline (the shell waits
      for the pipeline to finish).

  &&amp;   Causes asynchronous execution of the preceding pipeline (the shell does
      not wait for the pipeline	to finish).

  &&amp;&&amp;  Causes the list following	it to be executed only if the preceding	pipe-
      line returns a 0 (zero) exit value.

  ||  Causes the list following	it to be executed only if the preceding	pipe-
      line returns a nonzero exit value.

  The ;	(semicolon) and	&&amp; (ampersand) separators have equal precedence,	as do
  &&amp;&&amp; and ||.  The single-character separators have lower precedence than the
  double-character separators. A newline character without quotes following a
  pipeline functions the same as a ; (semicolon).  A pipeline or sequence can
  be enclosed in () (parentheses) to form a simple command.

  Job Control


  The shell associates a job with each pipeline.  It keeps a table of current
  jobs and assigns them	small integer numbers.	When you start a job asyn-
  chronously by	terminating the	command	with &&amp;,	the shell displays a line
  that looks like this:

       [1] 1234

  This line indicates that the job number is 1 and that	the job	is composed
  of one process with the process ID of	1234.  Use the built-in	jobs command
  to see the table of current jobs.

  If you are running a job and want to do something else, you can enter	the
  Suspend key sequence (normally <&lt;Ctrl-z>&gt;) which sends a stop signal to	the
  current job.	The shell then normally	indicates that the job has been
  stopped and it prints	another	prompt.	 You can then manipulate the state of
  this job, putting it in the background with the bg command, or run some
  other	commands and then eventually bring the job back	into the foreground
  with the foreground command fg.  The job suspension takes effect immedi-
  ately, and is	similar	to the Interrupt key sequence in that pending output
  and unread input are discarded.  A special key sequence, <&lt;Ctrl-y>&gt;, does not
  generate a stop signal until a program attempts to read it. (See the read()
  system call for more information.) This key sequence can usefully be typed
  ahead	when you have prepared some commands for a job that you	want to	stop
  after	it has read them.

  Multiple interactive loop based commands can be started and suspended.
  These	suspended commands can be restarted in any arbitrary order.  When a
  suspended job	is restarted, it must be run in	the foreground rather than in
  the background.  If an attempt is made to restart it in the background, the
  shell	restarts only the command that was suspended and terminates once the
  job completes	without	continuing with	the rest of the	loop.

  A job	being run in the background stops if it	tries to read from the termi-
  nal.	Background jobs	are normally allowed to	produce	output,	but this can
  be disabled by entering the stty tostop command.  If you set this terminal
  option, background jobs stop when they try to	produce	output like they do
  when they try	to read	input.

  There	are several ways to refer to jobs in the shell.	 Use the % (percent
  sign)	with the fg and	bg built-in commands to	control	the job.  This name
  can be either	the job	number or a prefix of the string that started the
  job, if this name is unique.	(% can be used to refer	to both	background
  and foreground jobs.)


  For example, if a make process is running as job number 1, you can refer to
  it as	%1.  You can also refer	to it as %make,	if there is only one job with
  a name that begins with the string make.  You	can also use the following
  characters to	specify	a job whose name contains string, if there is only
  one such job:

       %?string

  Just naming a	job brings it to the foreground, so %1 is a synonym for	fg
  %1, bringing job 1 back into the foreground.	Similarly, entering %1 &&amp;
  resumes job 1	in the background.  Thus, %ex normally restarts	a stopped ex
  job if there was only	one stopped job	whose name began with the string ex.

  The shell maintains a	notion of the current and previous jobs. In output
  produced by the built-in command jobs, the current job is marked with	a +
  (plus	sign) and the previous job with	a - (dash). The	abbreviation %+
  refers to the	current	job and	%- refers to the previous job.	For close
  analogy with the syntax of the history mechanism (described later), %% is
  also a synonym for the current job.

  Status Reporting


  The shell tracks the state of	each job and reports whenever a	job finishes
  or becomes blocked.  The shell prints	the status information just before it
  prints the prompt to avoid disturbing	the appearance of the terminal
  screen.  If, however,	you set	the notify shell variable, the shell notifies
  you immediately of changes of	status in background jobs.  There is also a
  notify shell command that marks a single process so that its status changes
  are immediately reported.  By	default	notify marks the current process.
  Simply enter notify after starting a background job to mark the job.

  When you try to leave	the shell while	jobs are stopped, you are warned that
  you have stopped jobs.  You can use the built-in jobs	command	to see what
  they are.  If	you then immediately exit the shell, or	use jobs and then
  exit,	the shell does not warn	you a second time, and the suspended jobs are
  terminated.

  File Name Completion


  The file name	completion feature is enabled by setting the shell variable
  filec.  The csh interactively	completes file names and user names from
  unique prefixes when they are	input from the terminal	followed by the
  escape character (the	<&lt;ESC>&gt; key or <&lt;Ctrl-[>&gt;)). For example, assume the
  current directory looks like this:

       DSC.OLD	bench  chaos  cmd     dev  mail	 xmpl.c	 xmpl.out
       DSC.NEW	bin    class  cmtest  lib  mbox	 xmpl.o

  The input is as follows:

       % vi ch<&lt;ESC>&gt;

  The csh completes the	prefix ch to the only matching file name chaos:

       vi chaos

  However, given the following command line:

       vi D<&lt;ESC>&gt;

  csh only expands the input as	follows:

       vi DSC.

  The csh sounds the terminal bell to indicate that the	expansion is incom-
  plete, because two file names	match the prefix D.

  If a partial file name is followed by	the End-of-File	character (shown here
  as <&lt;Ctrl-d>&gt;),	then instead of	completing the name, csh lists all file	names
  matching the prefix.	For example, the following input causes	all files
  beginning with D to be listed:

       vi D<&lt;Ctrl-d>&gt;

       DSC.NEW DSC.OLD

  The input line is then echoed	again for you to complete.

  The same system of <&lt;ESC>&gt; and <&lt;EOF>&gt; can also be used to expand	partial	user
  names, if the	word to	be completed (or listed) begins	with ~ (tilde).	 For
  example, entering the	following command line:

       cd ~ro<&lt;ESC>&gt;

  can produce the following expansion:

       cd ~root

  The use of the terminal bell to signal errors	or multiple matches can	be
  inhibited by setting the variable nobeep.

  Normally, all	files in the particular	directory are candidates for name
  completion.  Files with certain suffixes can be excluded from	consideration
  by setting the variable fignore to the list of suffixes to be	ignored.
  Thus,	if fignore is set by the following command:

       % set fignore = (.o .out)

  typing

       % vi x<&lt;ESC>&gt;

  results in the completion to

       % vi xmpl.c

  ignoring the files xmpl.o and	xmpl.out. However, if the only completion
  possible requires not	ignoring these suffixes, then they are not ignored.
  In addition, fignore does not	affect the listing of file names by <&lt;Ctrl-d>&gt;.
  All files are	listed regardless of their suffixes.

  History Substitution


  History substitution places words from previous command input	as portions
  of new commands, making it easy to repeat commands, repeat arguments of a
  previous command in the current command, or fix spelling mistakes in the
  previous command with	little typing. History substitutions begin with	the !
  (exclamation point) character	and can	begin anywhere on the command line,
  provided they	do not nest (in	other words, a history substitution cannot
  contain another history substitution). You can precede the ! with a \
  (backslash) to prevent the exclamation point's special meaning.  In addi-
  tion,	if you place an	! (exclamation point) before a space, tab, newline, =
  (equal sign),	or ( (left parenthesis), the exclamation point is passed to
  the parser unchanged.	(History substitutions also occur when you begin an
  input	line with a ^ (circumflex). This special abbreviation is described
  later.) The shell echoes any input line containing history substitutions
  before it executes that command line.


  Commands input from the terminal that	consist	of one or more words are
  saved	on the history list.  The history substitutions	reintroduce sequences
  of words from	these saved commands into the input stream.

  The history shell variable controls the size of the history list.  You must
  set the history shell	variable either	in the .cshrc file or on the command
  line with the	built-in set command.  The previous command is always
  retained, however, regardless	of the value of	history.  Commands in the
  history list are numbered sequentially, starting from	1. The built-in	his-
  tory command produces	output of the type:

	9  write michael
       10  ex write.c
       11  cat oldwrite.c
       12  diff	*write.c

  The command strings are shown	with their event numbers.  It is not usually
  necessary to use event numbers to refer to events, but you can have the
  current event	number displayed as part of your system	prompt by placing an
  ! (exclamation point)	in the prompt string assigned to the prompt variable.

  A full history reference contains an event specification, a word designa-
  tor, and one or more modifiers in the	following general format:

       event[:]word:modifier[:modifier]...

  Note that only one word can be modified.  A string that contains spaces is
  not allowed.

  In the previous sample of history command output, the	current	event number
  is 13.  Using	this example, the following refer to previous events:

  !10 Refers to	event number 10.

  !-2 Refers to	event number 11	(the current event minus 2).

  !d  Refers to	a command word beginning with d	(in this case, event number
      12).

  !?mic?
      Refers to	a command word that contains the string	mic (in	this case,
      event number 9).

  These	forms, without further modification, simply reintroduce	the words of
  the specified	events,	each separated by a single space. As a special case,
  !! refers to the previous command. (The !! command alone on an input line
  reruns the previous command.)

  To select words from an event, follow	the event specification	by a :
  (colon) and one of the following word	designators. The words of an input
  line are numbered sequentially, starting from	0 (zero), with the first
  (usually command) word being 0 (zero), the second word (first	argument)
  being	1, and so on.  The basic word designators are as follows:

  0   First word (command).

  n   The nth argument,	where n	> 0, for example, !!:3 recalls the third word
      of the previous command and !:2 recalls to the second word of the
      current command.	!#:n is	the same as !:n	and recalls the	nth word of
      the current command.

  ^   First word (word 1).

  $   Last word.

  %   Word matched by (the immediately preceding) ?string? history search.

  x-y Range of words from x through y.

  -y  Words 0-y.

  *   The second through the last words, or nothing if only one	word in
      event.

  x*  Words x- $

  x-  Like x*, but omits the last word ($).

  You can omit the : (colon) separating	the event specification	from the word
  designator if	the word designator begins with	a ^, $,	*, -, or %.  You can
  also place a sequence	of modifiers, each preceded by a : (colon), after the
  optional word	designator. The	following modifiers are	defined:

  &&amp;   Repeats the previous substitution.

  e   Removes all but the trailing extension .xxx.

  g   Applies the change globally, prefixing another modifier, for example
      g&&amp;.

  h   Removes a	trailing path name extension, leaving the head.

  p   Prints the new command, but does not execute it.

  q   Quotes the substituted words, thus preventing further substitutions.

  r   Removes a	trailing .xxx component, leaving the root name.

  s/l/r/
      Substitutes r for	l.  It is an error for no word to be applicable.

  t   Removes all leading path name components,	leaving	the tail.

  x   Like q, but breaks into words at space, tab or newline.

  Unless the modifier is preceded by a g, the change is	applied	only to	the
  first	modifiable word.

  The l	(left) side of a substitution is not a pattern in the sense of a
  string recognized by an editor; rather, it is	a word,	a single unit without
  spaces. Normally, a /	(slash)	delimits the word (l) and its replacement
  (r). However,	you can	use any	character as the delimiter.  Thus, in the
  following example the	= character becomes the	delimiter, allowing you	to
  include the /	in your	word:

       s=/usr/myfile=/usr/yourfile=

  If you include an &&amp; (ampersand) in the replacement (r), it is	replaced by
  the text from	the left-hand side (l).	A null l side is replaced by either
  the last l string or by the last string used in the contextual scan
  !?string?. You can omit the trailing delimiter (/) if	a newline character
  follows immediately.

  A history reference can be given without an event specification.  For	exam-
  ple, !$ refers to the	last argument of the previous command. If a history
  reference without an event specification is not the first history reference
  on the line, it refers to the	previous history reference on the line and
  not to a previous event.  For	example, in !?foo?^ !$,	!?foo?^	gives the
  first	argument of the	command	matching ?foo?,	and the	!$ gives the last
  argument of that same	command, not the last argument of the previous com-
  mand (as it would if it were on a line by itself).

  A special abbreviation of a history reference	occurs when the	first non-
  space	character of an	input line is a	^ (circumflex).	 This is equivalent
  to !:s^, providing a convenient shorthand for	substitutions on the text of
  the previous line. Thus, ^lb^lib corrects the	spelling of lib	in the previ-
  ous command. Finally,	a history substitution can be enclosed in { }
  (braces) to insulate it from the characters that follow. Thus, after ls -ld
  ~paul	you might specify !{l}a	to do ls -ld ~paula, or	!la to rerun a com-
  mand starting	with la.

  Command Line Editing (cmdedit)


  If you are using a video display terminal or a workstation terminal emula-
  tor, csh allows you to recall	and edit commands as if	you were using an
  editor; this capability is in	addition to the	history	mechanism.  This ver-
  sion of the C	shell provides intra-command line editing that includes
  features such	as a kill buffer, multiline named keyboard macros which	can
  be automatically saved and restored, convenient access to the	history	list,
  and user settable key	bindings.  A summary of	the currently available	func-
  tions	is provided below.  In most cases, the functionality is	apparent from
  the names of the routines in the list.

  The shell's editing mode is determined by the	value of the shell editmode
  variable which users should set to emacs or vi in their .cshrc files.	If
  editmode is not set, then the	shell will run in "dumb" mode. It is possible
  to set the mode after	the shell starts up; so	if you find yourself in
  "dumb" mode, you can alter the situation without having to log out and log
  in again.  Setting the editmode variable has two important side effects:
  (1) it causes	the key	bindings to be reevaluated, and	(2) it sets the	EDIT-
  MODE environment variable.  The latter has no	effect within the shell; so
  users	should not set the environment variable	directly in hopes of altering
  the editing mode.

  Terminal control capabilities	are extracted from the user's termcap file
  (usually /etc/termcap), using	the value of the shell variable	term, not the
  environment variable TERM, as	the terminal type.  If term is undefined,
  unknown, or if the associated	termcap	definition is inadequate, a warning
  will be displayed and	most, or all, of the editing features of the shell
  will be disabled.  It	is the user's responsibility to	make sure that term
  is set to an appropriate value before	the shell editor is initialized. Usu-
  ally this should be done in the .login file.	If editing is disabled
  because term is not properly set when	the shell starts up, simply setting
  term to the proper value will	normally cause the shell editor	to be reen-
  abled. NB: Setting the shell variable	term causes the	environment variable
  TERM to be set to the	same value. For	information on controlling the bell,
  see the ERRORS section.

  There	is a bind-to-key command in this shell,	which allows the functions
  listed in the	table on bindings below, and also user defined keyboard	mac-
  ros, to be bound to keys.  The form of the command is

  bind-to-key function key ...

  where	function is one	of the function	names from the list or else the	sin-
  gle character	name of	a keyboard macro and where key is a quoted string
  designating a	key sequence.  Control characters in the key designation
  should not be	entered	literally, but should be indicated by the prefix
  "\^",	e.g.  "\^X".  Similarly, escape	is indicated by	"\e".  A literal
  backslash is "\\". Escape and	control-X are the only legitimate "prefix"
  characters.  For vi mode, bindings prefixed with control-X are for insert
  mode.	 Otherwise, the	bindings are in	effect only in command mode. The fol-
  lowing mnemonics should be used:




  \^?	 delete	(rubout)
  \^c	 control character
  \n	 line feed (new	line)
  \b	 back space
  \t	 horizontal tab
  \v	 vertical tab
  \f	 form feed
  \r	 carriage return
  \e	 escape
  \nnn	 character code	in octal

  Since	the shell converts returns to newlines,	it is probably unwise to
  alter	the binding of newline.	A common binding is to bind KillRegion to
  Ctrl/U, which	would be accomplished using the	following command:

       bind-to-key KillRegion "\^U"

  During editor	initialization the shell will read a file named	.bindings in
  the user's home directory.  If you regularly want certain non-default	key
  bindings to be effective, put	the appropriate	bind-to-key commands in	your
  ~/.bindings file.

  NB: Do not place the bind-to-key commands in your ~/.cshrc or	~/.login
  file;	they must be in	the ~/.bindings	file.

  Invocation of	the history mechanism with "!" either causes the matched com-
  mand to be inserted on the command line for editing before execution or
  immediately executes the command.  This is controlled	by the shell variable
  edithist, which is automatically set,	when the shell variable	editmode is
  set, thereby allowing	editing	of previous commands invoked by	the history
  mechanism.  This feature may be turned off with the command "unset edith-
  ist",	which may be placed in the user's .cshrc file.

  The following	table shows the	current	functions and default key bindings:

  Emacs	    Function Name	       Remark
  ^B	    Backspace
  ESC-b	    BackwardWord
  ^A	    BeginningOfLine
  ^L	    ClearScreen
	    DefaultBinding
  ESC-n	    DefineNamedMacro	       name macro
  ^D	    DeleteCurrentChar
  ^H	    DeletePreviousChar
  ESC-d	    DeleteWord		       after cursor
	    EndOfFile		       exit shell
  ^E	    EndOfLine
	    EraseLine		       kills whole line
  ESC-h	    EraseWord		       before cursor
	    ExecuteMacro
  ESC-e	    ExecuteNamedMacro
  ESC-x	    ExecuteNamedMacro
  ^X-e	    ExecuteUnNamedMacro
  ESC-ESC   FilenameExpansion
  ESC-l	    FilenameList
  ^F	    ForwardChar
  ESC-f	    ForwardWord
	    GnuTransposeChars	       like gnu-emacs
	    IncrementalSearchForward
	    IncrementalSearchReverse
	    InsertChar		       self insert
  ^V	    InsertLiteralChar
  ^W	    KillRegion		       to kill buffer
  ^K	    KillToEOL		       to kill buffer
  ^X^R	    LoadMacroFile
  ^N	    NextHistEntry	       wraps around
  ^P	    PreviousHistEntry	       wraps around
  ^R	    Redisplay		       redraws line
  ^U	    Repetition		       greater than 0
  ^M,^J	    Return
  ^X^S	    SaveMacroFile

  ^@	    SetMark

				       default mark at
				       BOL
	    SearchReverse	       look for	next char
	    SearchForward	       look for	next char
  ^Q	    StartFlow		       (see FLOW CONTROL)
  ^X-(	    StartRemembering	       begin a macro
  ^S	    StopFlow		       (see FLOW CONTROL)
  ^X-)	    StopRemembering	       end a macro
  ^I	    Tab			       inserts 8 spaces
  ^T	    TransposeChars	       before cursor
	    WipeLine

				       kill line without
				       saving
  ^Y	    YankKillBuffer	       no kill ring

  Vi		   Function Name	      Remark
  A		   AppendToEOL

					      can't use	with
					      bind-to-key
  ^H		   BackSpace
  h		   BackSpace
  B		   BackwardWord
  b		   BackwardWord
  0		   BeginningOfLine
  ^		   BeginningOfLine
  s		   ChangeChar

					      can't use	with
					      bind-to-key
  c		   ChangeFollowingObject

					      can't use	with
					      bind-to-key
  C		   ChangeToEOL

					      can't use	with
					      bind-to-key
  S		   ChangeWholeLine

					      can't use	with
					      bind-to-key
  x		   DeleteCurrentChar
  d		   DeleteFollowingObject

					      can't use	with
					      bind-to-key
  X		   DeletePreviousChar

					      can't use	with
					      bind-to-key
  $		   EndOfLine
  ESC		   FilenameExpansion
  ^D		   FilenameListOrEof
  l		   ForwardChar
  SPACE		   ForwardChar
  w		   ForwardWord
  W		   ForwardWord
  e		   ForwardWord
  I		   InsertAtBOL

					      can't use	with
					      bind-to-key
  D		   KillToEOL
  @		   ExecuteNamedMacro
  +		   NextHistEntry
  j		   NextHistEntry
  ^N		   NextHistEntry
  -		   PreviousHistEntry
  k		   PreviousHistEntry
  ^P		   PreviousHistEntry
  ^L		   Redisplay
  ^R		   Redisplay
  z		   Redisplay
  1-9		   Repetition


  r		   ReplaceChar

					      can't use	with
					      bind-to-key
  LINEFEED	   Return
  RETURN	   Return
  /		   IncrementalSearchForward
  ?		   IncrementalSearchReverse
  f		   SearchForward
  F		   SearchReverse
  m		   SetMark
  a		   EnterViAppend

					      can't use	with
					      bind-to-key
  i		   EnterViInsert

					      can't use	with
					      bind-to-key
  p		   ViYankKillBuffer

					      can't use	with
					      bind-to-key
  P		   ViYankKillBuffer

					      can't use	with
					      bind-to-key
  Vi insert mode
  ^H		   DeletePreviousChar
  EraseChar	   DeletePreviousChar
  ^W		   EraseWord
  ESC		   ExitViInsert

					      can't use	with
					      bind-to-key
  ^D		   FilenameListOrEof
  ^Q		   InsertLiteralChar
  ^V		   InsertLiteralChar
  ^U		   KillRegion
  ^N		   NextHistEntry
  ^P		   PreviousHistEntry
  ^L		   Redisplay
  ^R		   Redisplay
  LINEFEED	   Return
  RETURN	   Return
  TAB		   Tab

  Users	may change the bindings	of functions to	keys by	means of the shell
  bind-to-key command.	These commands may be stored in	a file named .bind-
  ings in the user's home directory and	will then be read by the shell when
  the editor is	initialized.

  Flow control is handled by the terminal driver, not by the shell.  The ter-
  minal	driver normally	interprets ^S and ^Q as	a signal to respectively stop
  and restart output to	the terminal.  By default, the shell does not over-
  ride these "bindings", but the user may override them	by rebinding ^S	or ^Q
  to functions other than StopFlow and StartFlow.

  The functions	StopFlow and StartFlow can only	be usefully bound to the keys
  that the terminal driver interprets as performing the	corresponding flow
  control functions.  In other words, you cannot simply	bind these functions
  to other keys	in order to have them perform the flow control operations
  normally provided by ^S and ^Q.

  Keyboard macros can be used to simplify repetitive operations	and reduce
  typing lengthy commands.  For	example, the following lines illustrate	how
  to create a macro to startup Emacs and have it run the shell inside a
  buffer:

       % ^X(emacs -eshell
       % ^X)

  Notice that this is a	multiline macro, since it contains an embedded new-
  line.	 The user can give this	macro a	single character name, e.g. "e", as
  follows:

       % \ene	(escape-n-e).

  The macro may	then be	executed by typing "\exe".  It can also	be bound to a
  key using the	bind-to-key command. Macros can	be saved in files and can be
  reloaded automatically when the shell	starts up.

  Macro	Creation
      To create	a new unnamed macro, use the StartRemembering function which
      is bound by default to ^X(. Subsequent keystrokes, until the
      StopRemembering, ^X ), function is executed, are remembered as an
      "unnamed"	keyboard macro.	 It can	contain	at most	1024 characters.  You
      are not allowed to begin creating	another	macro during macro creation,
      but it is	okay to	execute	other macros, provided loops are not created.
      The unnamed macro	can be executed	using the ExecuteUnNamedMacro func-
      tion, bound to ^Xe. There	is only	one unnamed macro.

  Named	Macros
      Users can	have up	to 128 named macros.  To define	such a macro, first
      create an	unnamed	macro as above and then	give it	a name by executing
      the DefineNamedMacro function, bound to \en (escape-n).  The function
      takes a single character argument	which will be the name of the macro.
      Any previous macro with that same	name will be destroyed.

  Macro	Execution
      To execute a named macro simply use the ExecuteNamedMacro	function,
      bound to \ex, and	give it	the name of the	macro to be executed. Named
      macros can also be bound to keys using the built-in C shell command
      bind-to-key.

  Macro	Files
      Named keyboard macros can	be saved in files and loaded from files.  To
      save the named macros in a file simply type the file name	on the com-
      mand line	(by itself) and	then execute the SaveMacroFile function	bound
      to ^X^S. To read a file of previously saved macros type the file name
      on the command line and execute the LoadMacroFile	function bound to
      ^X^R. Success in each case is indicated by the erasure of	the file
      name.  It	is okay	to store macros	in several different macro files. NB:
      It is not	advisable to try to edit saved macros!

  Autoloading and AutoSaving Macros
      If the shell variable macrofiles is assigned (in the user's .cshrc
      file) the	names of one or	more files of saved keyboard macros, then
      those macro files	will be	automatically loaded when the shell starts
      up. Similarly, the variable savemacros can be assigned the name of a
      (single) file in which all named macros will be saved when the user
      logs out.

  NB: The names	of the incremental search functions have changed since ear-
  lier releases	of this	shell.

  Four search functions	are available to the user, but are not bound (by
  default) to keys.  If	you want to use	them, use the C	shell bind-to-key
  command to bind them to keys.

  IncrementalSearchForward
      When the user executes this function he is placed	in a read/search loop
      in which the string to be	found is built up character by character.  As
      each new character is added to the search	string the cursor is placed
      at the end of the	first match on the command line	following the posi-
      tion of the cursor when the function was executed.  You can reexecute
      the search function while	in the loop to cause the cursor	to move	to
      subsequent matches.  Type	ESC to exit the	loop.

  IncrementalSearchReverse
      This function is similar to IncrementalSearchForward except that the
      cursor is	placed at the beginning	of the first match on the command
      line preceding the position of the cursor	when the function was exe-
      cuted.

  SearchForward
      This function grabs the next character you type and searches for that
      character	from the position of the cursor	to the end of the command
      line, leaving the	cursor following the first instance of the character
      if one is	found.

  SearchReverse
      This function is like SearchForward except that it searches from where
      the cursor is to the beginning of	the command line.

  If the shell variable	breakchars is assigned a string, then the characters
  in that string are used to determine word boundaries.	 The default break
  characters are " ", ",", ^I, /, \, (,	), [, ], {, }, ., ;, >,	<, !, ^, &,
  and |. The user defined break	characters are used instead of,	not in addi-
  tion to, the default list.

  The display update functions take no advantage of the	capabilities of	smart
  terminals.  This will	be fixed in the	future.

  The command line cannot exceed 1024 characters if characters are being
  inserted in the middle of the	line; it can be	longer if characters are
  being	inserted at the	end, but once the 1K boundary is passed	the previous
  characters can no longer be edited or	redisplayed.

  The interactive input	routine	performs some initialization the first time
  it is	called.	 As a result some things are not interactively alterable.  It
  is also not possible for the user to turn off	echoing	of regular characters
  or to	take the terminal out of CBREAK	mode by	means of the stty command,
  for example, and have	it affect the function of the shell.

  Error	conditions within the editor functions are usually indicated by	an
  audible bell.	 If you	prefer a visual	signal and your	terminal has a visi-
  ble bell capability, then you	should set the variable	visiblebell in your
  .cshrc file.	If you want an audible bell also, then set both	visiblebell
  and audiblebell.  If you don't want to be told about your mistakes, you can
  set the nobell variable.

  Quoting with Single and Double Quotes


  Enclose strings in single and	double quotes to prevent all or	some of	the
  substitutions	that remain.  Enclosing	strings	in ' ' (single quotes)
  prevents any further interpretation except history substitution.  Enclosing
  strings in " " (double quotes) allows	further	variable and command expan-
  sion.	In both	cases, the text	that results becomes (all or part of) a	sin-
  gle word.  Only in one special case does a string quoted by "	" yield	parts
  of more than one word; strings quoted	by ' ' never do	(see Command Substi-
  tution).

  Alias	Substitution


  The shell maintains a	list of	aliases	that the alias and unalias built-in
  commands can establish, display, and modify. After the shell scans a com-
  mand line, it	divides	the line into distinct commands	and checks the first
  word of each command,	left to	right, to see if it has	an alias.  If an
  alias	exists,	the text defined as the	alias for that command is reread with
  the history mechanism, as if the alias were the previous input line.	The
  words	that result replace the	command	and argument list.  If no reference
  is made to the history list, the argument list is left unchanged.

  Thus,	if the alias for ls is ls -l, the shell	replaces the command ls	/usr
  with ls -l /usr.  The	argument list is left unchanged	because	there is no
  reference to the history list	in the command with an alias. Similarly, if
  the alias for	lookup is grep !^ /etc/passwd, then lookup bill	maps to	grep
  bill /etc/passwd.

  Here !^ refers to the	history	list and the shell replaces it with the	first
  argument in the input	line, in this case bill.  Note that you	can use	spe-
  cial pattern-matching	characters in an alias.	 Thus, the line:

       alias lprint 'pr	\!* | lpr'

  makes	a command that formats its arguments to	the line printer.  The !
  (exclamation point) is protected from	the shell in the alias so that it is
  not expanded until pr	runs.

  If an	alias is found,	the word transformation	of the input text is per-
  formed and the aliasing process begins again on the reformed input line. If
  the first word of the	new text is the	same as	the old, looping is prevented
  by flagging it to terminate the alias	process. Other loops are detected and
  cause	an error.

  Variable Substitution


  The shell maintains a	set of variables, each of which	has as its value a
  list of zero or more words. Some of these variables are set by the shell or
  referred to by it. For instance, the argv variable is	an image of the	shell
  variable list, and words that	comprise the value of this variable are
  referred to in special ways.

  You can display and change the values	of variables by	using the set and
  unset	commands. Of the variables referred to by the shell, a number are
  toggles (variables that turn on and off); the	shell does not care what
  their	value is, only whether they are	set or unset.  For instance, the ver-
  bose variable	is a toggle that causes	the words of each command to be
  echoed. The setting of this variable results from the	-v option on the com-
  mand line.

  Other	operations treat variables numerically.	 The @ command performs
  numeric calculations and the result is assigned to a variable.  Variable
  values are, however, always represented as (zero or more) strings.  For the
  purposes of numeric operations, the null string is considered	to be 0
  (zero), and the second and subsequent	words of multiword values are
  ignored.

  After	the input line is parsed and alias substitution	is performed, and
  before each command is executed, variable substitution is performed, keyed
  by $ (dollar sign) characters. You can prevent this expansion	by preceding
  the $	with a \ (backslash) except within " " (double quotes),	where it
  always occurs, or by using ' ' (single quotes), where	it never occurs.
  Strings quoted by ` `	(grave accents)	are interpreted	later (see Command
  Substitution), so variable substitution does not occur there until later,
  if at	all. A $ is passed unchanged if	followed by a space, tab, or newline.

  Input/output redirection is recognized and expanded before variable expan-
  sion occurs.	Otherwise, the command name and	complete argument list are
  expanded together. Therefore,	it is possible for the first (command) word
  to this point	to generate more than one word,	the first of which becomes
  the command name, and	the rest of which become arguments.

  Unless enclosed in " " or given the :q modifier, the results of variable
  substitution can themselves eventually be command and	file name substi-
  tuted.  Within pairs of double quotes, a variable whose value	consists of
  multiple words expands to a (portion of a) single word, with the words of
  the variable's value separated by spaces.  When you apply the	:q modifier
  to a substitution, the variable expands to multiple words. The individual
  words	are separated by spaces	and quoted to prevent later command or file
  name substitution.

  The following	notation allows	you to introduce variable values into the
  shell	input. Except as noted,	it is an error to reference a variable that
  is not set.

  $name

  ${name}
      Are replaced by the words	assigned to the	variable name, each separated
      by a space.  Braces insulate name	from following characters that would
      otherwise	be part	of it. Shell variable names begin with a letter	and
      consist of up to 20 letters and digits, including	the underscore char-
      acter.

      If name is not a shell variable but is set in the	environment, then
      that value is returned.  Be aware	that the : (colon) modifiers and the
      other forms given	below are not available	in this	case.

  $name[selector]

  ${name[selector]}
      Can be used to select only some of the words from	the value of name.
      The selector is subjected	to variable substitution and can consist of a
      single number or two numbers separated by	a - (dash). The	first word of
      a	variable's string value	is numbered 1.	If the first number of a
      range is omitted,	it defaults to 1.  If the last member of a range is
      omitted, it defaults to $#name (the total	number of words	in the vari-
      able).  The * (asterisk) selects all words.  It is not an	error for a
      range to be empty	if the second argument is omitted or in	range.

  $#name

  ${#name}
      Gives the	number of words	in the variable. This can be used as a
      [selector] (see previous notation).

  $0  Substitutes the name of the file from which command input	is being
      read. An error occurs if the name	is not known.

  $number

  ${number}
      Equivalent to $argv[number].

  $*  Equivalent to $argv[*].

  You can apply	the modifiers :gh, :gt,	:gr, :h, :t, :r, :q and	:x to the
  preceding substitutions. If {	} (braces) appear in the command form, the
  modifiers must appear	within the braces. Note	that the current implementa-
  tion allows only one : (colon) modifier on each $ variable expansion.

  The following	substitutions cannot be	changed	with : modifiers.

  $?name

  ${?name}
      Substitutes the string 1 if name is set, 0 if it is not.

  $?0 Substitutes 1 if the current input file name is known, 0 (zero) if it
      is not.

  $$  Substitutes the (decimal)	process	number of the (parent) shell.

  $<&lt;  Substitutes a line from the standard input, with no further interpreta-
      tion.  Use it to read from the keyboard in a shell script.



  Command and File name	Substitution


  The shell performs command and file name substitution	selectively on the
  arguments of built-in	commands. This means that it does not expand those
  parts	of expressions that are	not evaluated. For commands that are not
  internal (that is, built in) to the shell, the shell substitutes the com-
  mand name separately from the	argument list. This occurs very	late, after
  the shell performs input/output redirection, and in a	child of the main
  shell.

  Command Substitution


  The shell performs command substitution on a command string enclosed in ` `
  (grave accents). The shell normally breaks the output	from such a command
  into separate	words at spaces, tabs and newline characters, with null	words
  being	discarded; this	text then replaces the original	command	string.
  Within strings surrounded by " " (double quotes), the	shell treats only the
  newline character as a word separator, thus preserving spaces	and tabs.

  In any case, the single final	newline	character does not force a new word.
  Note that it is therefore possible for a command substitution	to yield only
  part of a word, even if the command outputs a	complete line.

  File Name Substitution


  If a word contains any of the	characters *, ?, [, or { or begins with	a ~
  (tilde), then	that word is a candidate for file name substitution, also
  known	as globbing. This word is then regarded	as a pattern, and replaced
  with a sorted	list of	file names that	match the pattern.

  In a list of words specifying	file name substitution,	it is an error for no
  pattern to match an existing file name, but it is not	required that each
  pattern match. Only the character-matching symbols (metacharacters) *, ?
  and [	imply pattern matching;	the characters ~ and { are more	like abbrevi-
  ations.

  In matching file names, the .	(dot) character	at the beginning of a file
  name or immediately following	a / (slash), as	well as	the / character, must
  be matched explicitly.  The *	(asterisk) character matches any string	of
  characters, including	the null string. The ? (question mark) character
  matches any single character.	The sequence [abcd] matches any	one of the
  enclosed characters. Within [	], a lexical range of characters can be	indi-
  cated	by two characters separated by a - (dash), as in [a-z].	 The charac-
  ters that match this pattern are defined by the current collating sequence.
  The collating	sequence is determined by the value of the LC_COLLATE or LANG
  environment variable.

  The ~	(tilde)	character at the beginning of a	file name is used to refer to
  home directories. Standing alone, the	~ expands to your home directory as
  reflected in the value of the	home shell variable. When followed by a	name
  that consists	of letters, digits, and	- (dash) characters, the shell
  searches for a user with that	name and substitutes that user's home direc-
  tory.	 Thus, ~ken might expand to /users/ken and ~ken/chmach to
  /users/ken/chmach.  If the ~ (tilde) character is followed by	a character
  other	than a letter or / (slash) or does not appear at the beginning of a
  word,	it is left undisturbed.

  The pattern a{b,c,d}e	is a shorthand for abe ace ade.	Left-to-right order
  is preserved,	with the results of the	matches	being sorted separately	at a
  low level to preserve	this order. This construct can be nested. Thus,	the
  shell	expands:

       ~source/s1/{oldls,ls}.c

  to the file names:

       /usr/source/s1/oldls.c /usr/source/s1/ls.c

  The preceding	example	assumes	the home directory for source is /usr/source.
  (Note	that these files may or	may not	exist.)

  Similarly, the shell expands:

       ../{memo,*box}

  to the paths:

       ../memo ../box ../mbox

  (Note	that memo was not sorted with the results of matching *box.)  As a
  special case,	{, }, and {} are passed	undisturbed.

  Redirecting Input and	Output


  You can redirect the standard	input and standard output of a command with
  the following	syntax:

  <&lt; file
      Opens file (which	is first variable, command and file name expanded) as
      the standard input.

  <&lt;<&lt; word
      Reads the	shell input up to a line that is identical to word. The	word
      is not subjected to variable, file name or command substitution; each
      input line is compared to	word before any	substitutions are done on
      this input line. Unless a	quoting	character (\, ", `, or ') appears in
      word, the	shell performs variable	and command substitution on the
      intervening lines, allowing \ to quote $,	\, and `. Commands that	are
      substituted have all spaces, tabs, and newline characters	preserved,
      except for the final newline character, which is dropped.	The resulting
      text is placed in	an anonymous temporary file and	given to the command
      as standard input.

  >&gt; file

  >&gt;! file

  >&gt;&&amp; file

  >&gt;&&amp;! file
      Uses file	as standard output. If the file	does not exist,	it is
      created; if the file exists, it is truncated, and	its previous contents
      are lost.

      If the noclobber shell variable is set, then the file must not exist or
      be a character special file (for example,	a terminal or /dev/null) or
      an error results.	This helps prevent the accidental destruction of
      files. In	this case, use the ! (exclamation point) forms to suppress
      this check.

      The forms	involving &&amp; (ampersand)	route the diagnostic output into the
      specified	file as	well as	the standard output.  file is expanded in the
      same way as <&lt; input file names.

  >&gt;>&gt; file

  >&gt;>&gt;&&amp; file

  >&gt;>&gt;! file

  >&gt;>&gt;&&amp;! file
      Uses file	as standard output like	>&gt; but places output at the end of the
      file. If the noclobber shell variable is set, it is an error for the
      file not to exist	unless one of the ! forms is given.  Otherwise,	it is
      similar to >&gt;.

  A command receives the environment in	which the shell	was invoked, as
  changed by the input/output parameters and the presence of the command in a
  pipeline. Thus, unlike some previous shells, commands	run from a shell
  script have no access	to the text of the commands by default;	rather they
  receive the original standard	input of the shell. Use	the <&lt;<&lt; mechanism to
  present inline data. This lets shell scripts function	as components of
  pipelines and	lets the shell read its	input in blocks.

  To redirect diagnostic output	through	a pipe with the	standard output, use
  the form |&&amp; (vertical	bar, ampersand)	rather than | (vertical	bar) alone.

  Control Flow


  The shell contains a number of commands that can be used to regulate the
  flow of control in command files (shell scripts) and (in limited but useful
  ways)	from terminal input. These commands all	operate	by forcing the shell
  to reread or skip in its input and, because of the implementation, restrict
  the placement	of some	of the commands.

  The foreach, switch, and while statements, and the if-then-else form of the
  if statement,	require	that the major keywords	appear in a single simple
  command on an	input line.

  If the shell input is	not seekable, the shell	buffers	input whenever a loop
  is being read	and performs seeks in the internal buffer to do	the rereading
  implied by the loop.	(To the	extent that this allows, backward gotos
  succeed on non-seekable inputs.)

  Built-In Commands


  Built-in commands are	executed within	the shell. If a	built-in command
  occurs as any	component of a pipeline	except the last, it is executed	in a
  subshell. The	csh searches for a csh built-in	command	first.	If a built-in
  does not exist, the csh searches through the directories specified by	the
  environment variable path for	a system-level command to execute.

  alias	[name [word_list]]
      If no arguments are specified, displays all aliases. If name is speci-
      fied, displays the alias for name. If a word_list	is also	specified,
      alias assigns the	specified word_list as the alias of name.  Command
      and file name substitution are performed on word_list.

  bg [%job ...]
      Puts the current (if %job	is not specified) or specified jobs into the
      background, continuing them if they were stopped.

  break
      Causes execution to resume after the end of the nearest enclosing
      foreach or while.	The remaining commands on the current line are exe-
      cuted. Multilevel	breaks are therefore possible by writing them all on
      one line.

  breaksw
      Causes a break from a switch; resumes after the endsw.

  case label:
      Defines a	label in a switch statement.  (See switch.)

  cd [directory]

  chdir	[directory]
      Changes the shell's working directory to directory. If no	argument is
      given, it	changes	to your	home directory.

      If directory is not found	as a subdirectory of the current directory
      (and does	not begin with /, ./ or	../), then each	component of the
      cdpath shell variable is checked to see if it has	a subdirectory direc-
      tory. Finally, if	all else fails,	but directory is a shell variable
      whose value begins with /, this is tried to see if it is a directory.

  continue
      Continues	execution of the nearest enclosing while or foreach.  The
      rest of the commands on the current line are executed.

  default:
      Labels the default case in a switch statement. The default should	come
      after all	case labels.

  dirs
      Displays the directory stack; the	top of the stack is at the left, the
      first directory in the stack being the current directory.

  echo [-n] word_list
      Writes the specified words to the	shell's	standard output, separated by
      spaces, and terminated with a newline character, unless the -n option
      is specified.

  else

  end

  endif

  endsw
      See the description of foreach, if, switch, and while below.

  eval argument	...
      Reads arguments as input to the shell and	executes the resulting com-
      mands.  This is usually used to execute commands generated as the
      result of	command	or variable substitution, since	parsing	occurs before
      these substitutions.

  exec command
      Executes the specified command in	place of the current shell.

  exit [(expression)]
      Exits the	shell with either the value of the status shell	variable, if
      no expression is specified, or with the value of the specified expres-
      sion.

  fg [%job ...]
      Brings the current (if %job is not specified) or specified job into the
      foreground, continuing them if they were stopped.

  foreach name (word_list)

  ...

  end Sets the variable	name to	each member of word_list successively and
      executes the sequence of commands	between	the foreach command and	the
      matching end.  (foreach and end commands must appear alone on separate
      lines.)

      Use the built-in continue	command	to continue the	loop and the built-in
      break command to terminate it prematurely.  When this command is read
      from the terminal, the loop is read once,	prompting with ? before	any
      statement	in the loop is executed. If you	make a mistake in entering a
      loop at the terminal, it can be corrected	before you run the loop.
      Commands within loops prompted for by ? are not placed in	the history
      list.

  glob word_list
      Functions	like echo, but does not	recognize \ (backslash)	escapes	and
      delimits words by	null characters	in the output. Useful if you want to
      use the shell to perform file name substitution to expand	a list of
      words.

  goto word
      Performs file name and command expansion on the specified	word to	yield
      a	string of the form label:.  The	shell rewinds its input	as much	as
      possible and searches for	a line of the form label:, possibly preceded
      by spaces	or tabs. Execution continues after the line specified by
      word.

  history [-h] [-r] [number]
      Displays the history event list; by default, the oldest events are
      displayed	first. If you specify a	number,	only the number	most recent
      events are displayed.  The -r option reverses the	display	order to the
      most recent first, rather	than the oldest	first.	The -h option
      displays the history list	without	leading	numbers.  Use this to produce
      files suitable for sourcing using	the source command.

  if (expression) command
      Executes the single command (including its arguments) if the specified
      expression evaluates TRUE.  Variable substitution	on command happens
      early, at	the same time it does for the rest of the if command.  The
      command argument must be a simple	command	(rather	than a pipeline, com-
      mand list, alias,	or parenthesized command list).	Note that
      input/output redirection occurs even if expression is FALSE and command
      is not executed.

  if (expression) then

  ...

  else if (expression2)	then

  ...

  else

  ...

  endif
      If expression is TRUE, executes the commands following the first then
      up to the	first else; otherwise, if expression2 is TRUE, executes	the
      commands following the second then up to the second else.	 Any number
      of else-if pairs are possible; only one endif is needed.	The else part
      is optional.  (The words else and	endif must appear at the beginning of
      input lines.  The	if command must	appear alone on	its input line or
      after an else.)

  inlib	library_name
      This command is no longer	supported.  See	the loader(5) reference	page
      for information on using shared libraries.

  jobs [-l]
      Lists the	active jobs; with the -l option, lists process IDs in addi-
      tion to job numbers, status, and the command.

  kill [-l] [-sig] [%job ...] |	[-sig] [PID ...]
      Sends either the TERM (terminate)	signal or the specified	signal to the
      jobs or processes	that you specify.  Signals are either given by number
      or by name (as given in /usr/include/sys/signal.h, stripped of the pre-
      fix SIG).	The signal names are listed by kill -l.	There is no default
      job; specifying kill with	no job or PID does not send a signal to	the
      current job.  If the signal being	sent is	SIGTERM	(terminate) or SIGHUP
      (hangup),	then the job or	process	is sent	a SIGCONT (continue) signal
      as well.

  limit	[-h] [resource]	[maximum_use]
      Limits the usage by the current process and each process it creates not
      to (individually)	exceed maximum_use on the specified resource.  If no
      maximum_use is given, then the current limit is displayed; if no
      resource is given, then all limitations are given.

      If the -h	option is given, the hard limits are used instead of the
      current limits.  The hard	limits impose a	ceiling	on the values of the
      current limits.  Only the	superuser can raise the	hard limits, but a
      user can lower or	raise the current limits within	the legal range.

      Controllable resources currently include addresspace (the	maximum
      address space in bytes for a process), coredumpsize (the size of the
      largest core dump	that is	created), cputime (the maximum number of CPU
      seconds to be used by each process), datasize (the maximum growth	of
      the data region allowed beyond the end of	the program text), descrip-
      tors (the	maximum	number of open files for each process),	filesize (the
      largest single file that can be created),	memoryuse (the maximum size
      to which a process's resident set	size can grow),	and stacksize (the
      maximum size of the automatically	extended stack region).

      The maximum_use can be specified as a floating-point or integer number
      followed by a scale factor: k or kbytes (1024 bytes), m or megabytes,
      or b or blocks. For both resource	names and scale	factors, unambiguous
      prefixes of the names suffice.  The scale	factor optionally can be
      separated	from the numeric value by a space; 1024k is exactly
      equivalent to 1024 k. The	filesize can be	lowered	by an instance of
      csh, but can only	be raised by an	instance whose effective user ID is
      root. For	more information, refer	to the documentation for the ulimit
      system call.

  login
      Terminates a login shell and replaces it with an instance	of
      /usr/bin/login.  This is one way to log out (included for	compatibility
      with sh).

  logout
      Terminates a login shell.	 Especially useful if ignoreeof	is set.

  newgrp [-] [group]
      Changes the primary group	identification of the current shell process
      to group.	 If you	specify	a - (dash), newgrp changes the login environ-
      ment to the login	environment of the new group.  If you do not specify
      a	group, newgrp changes the group	identification to that specified for
      the current user in the /etc/passwd file.	 The newgrp command recog-
      nizes group names	only; it does not recognize group ID numbers.

      Only a user who is root can change the primary group of the shell	to
      one in which the user does not have membership. Any active user-
      generated	shell is terminated when the newgrp command is used.

  nice [+number] [command]
      Without arguments, nice sets the priority	of commands run	in this	shell
      to 4.  The +number arguments sets	the priority to	the specified number.
      The command argument causes command to run at priority 4 (without	the
      +number argument)	or at priority number (if +number is specified).  The
      greater the number, the less CPU the process gets.  The superuser	can
      raise the	priority by using nice with a negative number.	The command
      is always	executed in a subshell,	and the	restrictions placed on
      commands in simple if statements apply.

  nohup	[command]
      The first	form causes hangups to be ignored for the remainder of the
      shell script. The	second form causes the specified command to be run
      with hangups ignored. To run a pipeline or list of commands with this
      form, put	the pipeline or	list in	a shell	script,	give the script	exe-
      cute permission, and use the shell script	as the command.	All processes
      run in the background with &&amp; are effectively protected from being	sent
      a	hangup signal when you log out,	but are	still subject to explicitly
      sent hangups unless nohup	is used.

  notify [%job ...]
      Causes the shell to notify you asynchronously when the status of the
      current (if %job is not specified) or specified jobs changes.  Nor-
      mally, notification is presented immediately before the shell prompt.
      This is automatic	if the notify shell variable is	set.

  onintr [-] [label]
      Controls the action of the shell on interrupts. The first	form restores
      the default action of the	shell on interrupts, which is to terminate
      shell scripts or to return to the	terminal command input level.  The
      second form causes all interrupts	to be ignored.	The third form causes
      the shell	to execute a goto label	when it	receives an interrupt or when
      a	child process terminates due to	an interruption.

      In any case, if the shell	is running in the background and interrupts
      are being	ignored, all forms of onintr have no meaning and interrupts
      continue to be ignored by	the shell and all invoked commands.

  popd [+number]
      Pops the directory stack (removes	the top	entry),	changing directories
      to the new top directory.	 With a	+number	argument, popd discards	the
      number entry in the stack. The elements of the directory stack are num-
      bered from the top, starting at 0	(zero).

  pushd	[name] [+n]
      Changes to the directory that comes to the top of	the stack.  With no
      arguments, pushd exchanges the top two elements of the directory stack.
      With a name argument, pushd changes to the new directory (that is, cd)
      and pushes the old current working directory (given in the cwd shell
      variable)	onto the directory stack.  With	a numeric argument, pushd
      rotates the number argument of the directory stack around	to be the top
      element and changes directory to it.  The	members	of the directory
      stack are	numbered from the top, starting	at 0 (zero).

  rehash
      Causes the internal hash table of	the contents of	the directories	in
      the path shell variable to be recomputed.	This is	needed if new com-
      mands are	added to directories in	path while you are logged in.  This
      should be	necessary only if commands are added to	one of your own
      directories, or if someone changes the contents of one of	the system
      directories.

  repeat count command
      Executes the specified command, which is subject to the same restric-
      tions as in the simple if	statement, count times.	Note that
      input/output redirections	occur exactly once, even if count is 0
      (zero).

  rmlib	library_name
      This command is no longer	supported.  See	the loader(5) reference	page
      for information on using shared libraries.

  set

  set name

  set name=word

  set name[index]=word

  set name=(word_list)
      The first	form of	the command displays the value of all shell vari-
      ables. Variables that have values	other than a single word are
      displayed	as a parenthesized word	list. The second form sets name	to
      the null string. The third form sets name	to the single word.  The
      fourth form sets the indexth component of	name to	word; this component
      must already exist.  The final form sets name to the list	of words in
      word_list. In all	cases, the value is command and	file name expanded.
      These arguments can be repeated to set multiple values in	a single set
      command. Note however, that variable expansion happens for all argu-
      ments before any setting occurs.

  setenv name value
      Sets the value of	the environment	variable name to be value, a single
      string. The most commonly	used environment variables USER, TERM, HOME,
      and PATH are automatically imported to and exported from the csh vari-
      ables user, term,	home, and path,	so there is no need to use setenv for
      these common environment variables.

      If you modify the	LC_COLLATE or LANG environment variables, the current
      international character support environment and collating	sequence are
      changed as specified for subsequent commands executed from the shell.

  shift	[variable]
      Shifts to	the left the members of	argv (discarding argv[1]) or the
      specified	variable. An error occurs if argv is not set or	has fewer
      than two strings assigned	to it.

  source [-h] name
      Causes the shell to read commands	from name.  You	can nest source	com-
      mands.  However, if they are nested too deeply, the shell	can run	out
      of file descriptors.  An error in	a source at any	level terminates all
      nested source commands. Normally,	input during source commands is	not
      placed on	the history list. The -h option	causes the commands to be
      placed in	the history list without being executed.

  stop [%job ...]
      Stops the	current	(if %job is not	specified) or specified	job that is
      executing	in the background.

  suspend
      Causes the shell to suspend execution by sending itself a	stop signal.
      This command gives an error message if attempted from a login shell.
      Since csh	normally ignores the stop signal, this is the only way of
      suspending the shell.

  switch (string)

  case string1:	...

  breaksw ...

  default: ...

  breaksw

  endsw
      Successively matches each	case label (string1) against string, which is
      first command and	file name expanded. Use	the pattern-matching charac-
      ters *, ?, and [...] in the case labels, which are variable expanded.
      If none of the labels match before a default label is found, then	exe-
      cution begins after the default label. Each case label and the default
      label must appear	at the beginning of a line.

      The breaksw command causes execution to continue after the endsw com-
      mand.  Otherwise,	control	can fall through case labels and the default
      labels, as in C.

      If no label matches and there is no default, execution continues after
      the endsw	command.

  time [command]
      With no argument,	displays a summary of time used	by this	shell and its
      children.	 If arguments are given, the specified command is timed	and a
      time summary (as described under the time	shell variable)	is displayed.
      If necessary, an extra shell is created to display the time when the
      command completes.

  umask	[value]
      Displays the file	creation mask (first form) or sets it to the speci-
      fied value (second form).	 The mask is given as an octal value.  Common
      values for the mask are 002, giving all access to	the owner and group,
      and assigning read and execute access to others, or 022, giving all
      access to	the owner, and assigning read and execute access to users in
      the group	and others.

  unalias pattern
      Discards all aliases with	names that match pattern. Thus,	all aliases
      are removed by unalias *.	 The absence of	aliases	that match pattern
      does not cause an	error.

  unhash
      Disables the use of the internal hash table to speed location of exe-
      cuted programs.

  unlimit [-h] [resource]
      Removes the limitation on	resource.  If no resource is specified,	then
      all resource limitations are removed.

      If -h is given, the corresponding	hard limits are	removed.  Only the
      superuser	can do this.

  unset	pattern
      Removes all variables with names that match pattern.  Use	unset *	to
      remove all variables. The	absence	of variables that match	pattern	is
      not an error.

  unsetenv pattern
      Removes all variables with names that match pattern from the environ-
      ment.  See also the setenv command (discussed earlier in this list).

  wait
      Waits for	all background jobs to terminate. If the shell is interac-
      tive, an interrupt can disrupt the wait, at which	time the shell
      displays the names and job numbers of all	jobs known to be outstanding.

  which	[ -U ] name ...
      Takes a list of names and	looks for the files which would	be executed
      had these	names been given as commands.  This built-in command works
      like /usr/bin/which if the -U option is given; without the option, the
      built-in command provides	more useful information	by identifying shell
      built-ins	and aliases.  See which(1) for more information.

  while	(expression)

  ...

  end While expression evaluates as nonzero, executes the commands between
      the while	and the	matching end.  You can use the break command to	ter-
      minate the loop prematurely and the continue command to continue the
      loop. (The while and end must appear alone on their input	lines.)	If
      the input	is a terminal, prompting occurs	the first time through the
      loop, as for the foreach statement.

  %job
      Brings the specified job into the	foreground.

  %job &&amp;
      Continues	the specified job in the background.

  @

  @ name = expression

  @ name[index]	= expression
      The first	form displays the values of all	the shell variables.  The
      second form sets the specified name to the value of expression. If the
      expression contains <&lt;, >&gt;,	&&amp;, or |, at least this part of the expression
      must be placed within (  ) (parentheses).	 The third form	assigns	the
      value of expression to the indexth argument of name.  Both name and its
      indexth component	must already exist.

      C	operators, such	as *= and +=, are available. White space separating
      the name from the	assignment operator is optional. Spaces	are, however,
      mandatory	in separating components of expression,	which would otherwise
      be single	words.

      Special postfix ++ and - - operators increment and decrement name,
      respectively, for	example	@ i++.

  Expressions


  The built-in commands	@, exit, if, and while accept expressions that
  include operators similar to those of	C, but with a precedence from right
  to left instead of from left to right. The following operators are avail-
  able:

       ( )
       ~
       !
       *    /	 %
       +    -
       <<   >>
       <=   >=	 <    >
       ==   !=	 =~   !~
       &
       ^
       |
       &&
       ||

  In the preceding list, operators of equal precedence appear on the same
  line,	below those lines containing operators (if any)	that have greater
  precedence, and above	those lines containing operators having	lesser pre-
  cedence.  The	==, !=,	=~, and	!~ operators compare their arguments as
  strings; all others operate on numbers. The =~ and !~	operators are similar
  to !=	and ==,	except that the	rightmost side is a pattern against which the
  left-hand operand is matched.	This reduces the need for use of the switch
  statement in shell scripts when all that is really needed is pattern match-
  ing.

  Null or missing arguments are	considered 0 (zero). The result	of all
  expressions are strings, which represent decimal numbers. It is important
  to note that no two components of an expression can appear in	the same
  word.	 Except	when next to components	of expressions that are	syntactically
  significant to the parser (&&amp;,	|, <&lt;, >&gt;, -, (, and ) ) expression components
  should be surrounded with spaces.

  Also available in expressions	as primitive operands are command executions
  enclosed in {	and } and file inquiries of the	form -l	name where l is	one
  of the following:

  r   Read access

  w   Write access

  x   Execute access

  e   Existence

  o   Ownership

  z   Zero size

  f   Plain file

  d   Directory

  l   Symbolic link

  The specified	file is	command	and file name expanded and then	tested to see
  if it	has the	specified relationship to the real user. If the	file does not
  exist	or is inaccessible, then all inquiries return FALSE, that is, 0
  (zero).  Command executions succeed, returning TRUE (1), if the command
  exits	with status 0 (zero); otherwise, they fail, returning FALSE (0). If
  more detailed	status information is required,	execute	the command outside
  of an	expression and examine the status shell	variable.

  Predefined and Environment Variables


  The following	variables have special meaning to the shell. Of	these, argv,
  cwd, home, path, prompt, shell, and status are always	set by the shell.
  Except for cwd and status, this setting occurs only at initialization; the
  remaining variables maintain their settings unless you explicitly reset
  them.

  The csh command copies the USER environment variable into the	variable
  user,	TERM into term,	and HOME into home, and	copies these back into the
  environment whenever the normal shell	variables are reset.  The PATH
  environment variable is handled similarly; it	is not necessary to worry
  about	their settings other than in the .cshrc	file.  Each csh	subprocess
  imports the definition of path from the environment, and exports it again
  if you then change it.

  argv
      Is set to	the arguments to the shell.  It	is from	this variable that
      positional parameters are	substituted, for example, $1 is	replaced by
      $argv[1],	and so on.

  autologout
      If autologout is set to a	value greater than 0 (zero), the shell ter-
      minates if a command is not entered within the prescribed	number of
      minutes after issuing the	shell prompt.

      Auto-logout is enabled by	default	if the shell runs as a login shell
      and if the standard input	stream is not a	pseudo tty and the DISPLAY
      environment variable is not set.	Auto-logout can	be disabled by adding
      the following line to your .login	or .cshrc file:


	   set autologout = 0

  cdpath
      Gives a list of alternate	directories to be searched to find subdirec-
      tories in	chdir commands.

  cwd Is set to	the full path name of the current directory.

  echo
      Causes each command and its arguments to be echoed to standard output
      just before it is	executed.  It is set when the -x command line option
      is specified. For	nonbuilt-in commands, all expansions occur before
      echoing. Built-in	commands are echoed before command and file name sub-
      stitution, since these substitutions are then done selectively.

  filec
      Enables file name	completion.

  histchars
      Changes the characters used in history substitution when given a string
      value. The first character of its	value is used as the history substi-
      tution character,	replacing the default character	! (exclamation
      point). The second character of its value	replaces the character ^
      (circumflex) in quick substitutions.

  history
      Controls the existence and size of the history buffer. All commands
      (executable or not) are saved in the history buffer. Values of history
      that are too large can run the shell out of memory. The last executed
      command is always	saved on the history list even if history is left
      unset.

  home
      Contains the absolute path name to the home directory of the user, ini-
      tialized from the	environment.  The file name expansion of ~ (tilde)
      refers to	this variable.

  ignoreeof
      Causes the shell to ignore End-of-File characters	from input devices
      that are terminals. This prevents	shells from accidentally being killed
      when they	read an	End-of-File character.

  LANG
      Specifies	the locale of your system, which is comprised of three parts:
      language,	territory, and codeset.	 The default locale is the C locale,
      which specifies the value	English	for language, U.S. for territory, and
      ASCII for	codeset. The locale specified for the LANG variable controls
      the language applied to messages.	 Unless	set explicitly,	the
      LC_COLLATE, LC_CTYPE, LC_MESSAGES, LC_MONETARY, LC_NUMERIC, and LC_TIME
      variables	also derive their settings from	the locale set for LANG.

  LC_COLLATE
      Specifies	the collating sequence to use when sorting names and when
      character	ranges occur in	patterns.  The default value is	the collating
      sequence for American English.

  LC_CTYPE
      Specifies	the character classification information to use	on your	sys-
      tem.  The	default	value is American English.

  LC_MESSAGES
      Specifies	the language that the system expects for user input of yes
      and no strings. The default value	is American English.

  LC_MONETARY
      Specifies	the monetary format for	your system.  The default value	is
      the monetary format for American English.

  LC_NUMERIC
      Specifies	the numeric format for your system.  The default value is the
      numeric format for American English.

  LC_TIME
      Specifies	the date and time format for your system.  The default value
      is the date and time format for American English.

  mail
      Specifies	the files where	the shell checks for mail. This	is done	after
      each command completion that results in a	prompt,	if a specified inter-
      val has elapsed.	The shell displays the message You have	new mail if
      the file has been	modified since the last	check.

      If the first word	of the value of	mail is	numeric, it specifies a	dif-
      ferent mail checking interval (in	seconds) than the default (10
      minutes).

      If you specify multiple mail files, the shell displays the message New
      mail in file when	there is mail in file.

  NLSPATH
      Specifies	a list of directories to search	to find	message	catalogs.

  noclobber
      If set, places restrictions on output redirection	to ensure that files
      are not accidentally destroyed, and that >&gt;>&gt; redirections refer to
      existing files. (See also	Redirecting Input and Output.)

  noglob
      If set, inhibits file name expansion. This is most useful	in shell
      scripts that do not deal with file names,	or after a list	of file	names
      is obtained and further expansions are not desirable.

  nonomatch
      If set, does not return an error for a file name expansion that does
      not match	any existing files; rather, the	primitive pattern is
      returned.	It is still an error for the primitive pattern to be mal-
      formed, for example, echo	[ still	gives an error.

  notify
      If set, causes the shell to notify you asynchronously of background job
      completion.  The default is to present job status	changes	immediately
      before printing a	prompt.

  path
      Each word	of the path variable specifies a directory in which commands
      are to be	sought for execution.  A null word specifies the current
      directory. If no path variable is	set, then only full path names are
      executed.	The usual search path is the current directory and /usr/bin,
      but this can vary	from system to system. A shell that is given neither
      the -c nor the -t	option normally	hashes the contents of the direc-
      tories in	the path variable after	reading	.cshrc and each	time the path
      variable is reset.  If new commands are added to these directories
      while the	shell is active, it is necessary to execute the	rehash com-
      mand in order to access the new commands.

  prompt
      The string that is printed before	each command is	read from an interac-
      tive terminal input.  If a ! (exclamation	point) appears in the string,
      it is replaced by	the current event number, unless it is preceded	by a
      \	(backslash).  The default prompt is %, # for the superuser.

  savehist
      When given a numeric value, controls the number of entries of the	his-
      tory list	that are saved in ~/.history when you log out. All commands
      (executable or not) that are in the history list are saved. During
      startup, the shell sources ~/.history into the history list, enabling
      history to be saved across logins. Very large values of savehist slow
      down the shell during startup.

  shell
      The file in which	the shell resides. This	is used	in forking shells to
      interpret	files that have	execute	bits set, but that are not executable
      by the system. (See Nonbuilt-In Command Execution.) This is initialized
      to the (system-dependent)	location of the	shell.

  status
      The status returned by the last command. If it terminated	abnormally,
      then 0200	is added to the	status.	Built-in commands that fail return
      exit status 1; all other built-in	commands set status 0 (zero).

  time
      Controls automatic timing	of commands, and the line displayed by a
      built-in time command.  The value	can consist of zero, one, or two
      words.

      The first	word is	the threshold for automatic timing, measured in	CPU
      seconds; for any command that takes at least that	many CPU seconds, the
      shell displays a line showing the	timing information when	that command
      finishes.

      The second word is a string, enclosed in ' ' (single quotes) or "	"
      (double quotes), specifying the timing line to be	displayed; it con-
      trols both the automatic display and the output of the time command.
      The string can contain any combination of	text as	well as	the following
      specifiers, which	must be	uppercase characters and preceded by a %
      (percent sign) as	shown.	Sequences such as \n are not treated as	spe-
      cial characters in the string.

      %D  Kilobytes of data space.

      %E  Elapsed time,	measured in seconds.

      %F  Number of page faults.

      %I  Number of blocks read	during I/O operations.

      %K  Kilobytes of stack space.

      %M  Total	kilobytes of memory.

      %O  Number of blocks written during I/O operations.

      %P  CPU time (both system	and user) as a percentage of elapsed time.

      %S  System time: CPU seconds used	by system calls.

      %U  User time: CPU seconds used by the process outside of	system calls.

      %W  Number of times the process was swapped.

      %X  Kilobytes of text space.

      If the first word	is zero	or if the time variable	is set with no value,
      every command is timed.  The default string displayed, when the second
      word is not supplied, is as follows:


	   %Uu %Ss %E %P% %X+%Dk %I+%Oio %Fpf+%Ww

  verbose
      Causes the words of each command to be displayed on the standard output
      after history substitution.  Set by the -v command line option.

  Nonbuilt-In Command Execution


  When a command to be executed	is found not to	be a built-in command, the
  shell	attempts to execute the	command	with the execv() system	call.

  Each word in the path	shell variable names a directory from which the	shell
  attempts to execute the command (if the command does not begin with a	/
  (slash)). If it is given neither a -c	nor a -t option, the shell hashes the
  names	in these directories into an internal table so that it only tries an
  execv	in a directory if there	is a possibility that the command resides
  there. This greatly speeds command location when a large number of direc-
  tories are present in	the search path.  If this mechanism was	turned off
  (with	unhash), or if the shell was given a -c	or -t argument (and in any
  case,	for each directory component of	path that does not begin with a	/),
  the shell concatenates the directory name with the given command name	to
  form a path name of a	file, which it then attempts to	execute.

  Commands in parentheses are always executed in a subshell. Thus, (cd ; pwd)
  ; pwd	displays the home directory and	then the current directory, without
  changing the current directory location; whereas, cd ; pwd changes the
  current directory location to	the home directory, and	prints the home
  directory. Commands in parentheses are most often used to prevent chdir
  from affecting the current shell.

  If the file has execute permissions but is not an executable binary to the
  system, then it is assumed to	be a file containing shell commands and	a new
  shell	is created to read it.

  If there is an alias for shell, then the words of the	alias are prefixed to
  the argument list to form the	shell command.	The first word of the alias
  should be the	full path name of the shell (for example, $shell). Note	that
  this is a special, late-occurring case of alias substitution and only
  allows words to be prefixed to the argument list without modification.

  Signal Handling


  The shell normally ignores SIGQUIT signals. Jobs running in the background
  (either by &&amp; or the bg or %...&&amp; commands) are	immune to signals generated
  from the keyboard (SIGINT, SIGQUIT, and SIGHUP). Other signals have the
  values the shell inherited from its parent. You can control the shell's
  handling of interrupts and terminate signals in shell	scripts	with onintr.
  Login	shells catch the SIGTERM (terminate) signal; otherwise,	this signal
  is passed on to children from	the state in the shell's parent.  In no	case
  are interrupts allowed when a	login shell is reading the .logout file.






  Limitations


  The following	are csh	limitations:

    +  Words can be no longer than 1024	bytes.

    +  Argument	lists are limited to 38912 bytes.  However, the	argument list
       space is	shared with the	space for environment variables; having	a
       large list of environment variables can severely	limit the allowable
       argument	list length.

    +  The number of arguments to a command that involves file name expansion
       is limited to 1/6th the number of characters allowed in an argument
       list.

    +  Command substitutions can substitute no more characters than are
       allowed in an argument list.

    +  To detect looping, the shell restricts the number of alias substitu-
       tions on	a single line to 20.

    +  Words can also be separated by double spaces.

    +  The job control is not supported	in the non-interactive mode of opera-
       tion.

  Character Classes


  You can use the following notation to	match file names within	a range	indi-
  cation:

  [:charclass:]

  This format instructs	the system to match any	single character belonging to
  charclass; the defined classes correspond to ctype() subroutines as fol-
  lows:

       alnum
       alpha
       cntrl
       digit
       graph
       lower
       print
       punct
       space
       upper
       xdigit

  Your locale might define additional character	properties, such as the	fol-
  lowing:

       [:vowel:]

  The preceding	character class	could be TRUE for a, e,	i, o, u, or y.	You
  could	then use [:vowel] inside a set construction to match any vowel.
  Refer	to The LC_CTYPE	Category section of the	locale file format reference
  page for more	information.






RESTRICTIONS

  Due to problems with the getrusage system call, csh incorrectly returns a
  value	of 0 for each of the following fields when the built-in	time(3)	func-
  tion or the time shell variable is used:

  %D   Kilobytes of data space
  %F   Number of page faults
  %K   Kilobytes of stack space
  %W   Number of times the process was swapped
  %X   Kilobytes of text space

RETURN VALUES

  For information about	return values, see the following sections: sallyShell
  Commands, Expressions, Predefined and	Environment Variables, and OPTIONS.

FILES

  $HOME/.cshrc
      C	shell startup file; read at beginning of execution by each C shell.

  $HOME/.login
      Read by login shell (after .cshrc) at login.

  $HOME/.logout
      Read by login shell at logout.

  /usr/bin/sh
      The path to the default shell.

  /tmp/sh*
      Temporary	file for <&lt;<&lt;.

  /etc/passwd
      Contains user information.

SEE ALSO

  Commands:  alias(1), bg(1), cd(1), echo(1), fg(1), hash(1), jobs(1),
  kill(1), ksh(1), newgrp(1), nice(1), nohup(1), sh(1),	Bourne shell sh(1b),
  POSIX	shell sh(1p), time(1), ulimit(1), umask(1), unalias(1),	wait(1)

  Functions:  access(2), chdir(2), exec(2), fork(2), getrlimit(2), pipe(2),
  umask(2), wait(2)

  Files:  locale(4), null(7)

  Miscellaneous:  loader(5)

  Command and Shell User's Guide