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TCSH(1)								       TCSH(1)

NAME
       tcsh - C	shell with file	name completion	and command line editing

SYNOPSIS
       tcsh [-bcdefFimnqstvVxX]	[-Dname[=value]] [arg ...]
       tcsh -l

DESCRIPTION
       tcsh  is	 an enhanced but completely compatible version of the Berkeley
       UNIX C shell, csh(1).  It is a command language interpreter usable both
       as an interactive login shell and a shell script	command	processor.  It
       includes	a command-line editor  (see  The  command-line	editor),  pro-
       grammable  word	completion (see	Completion and listing), spelling cor-
       rection (see Spelling correction), a  history  mechanism	 (see  History
       substitution),  job  control  (see  Jobs) and a C-like syntax.  The NEW
       FEATURES	section	describes major	 enhancements  of  tcsh	 over  csh(1).
       Throughout  this	 manual,  features  of	tcsh  not found	in most	csh(1)
       implementations (specifically, the 4.4BSD csh) are labeled with	`(+)',
       and features which are present in csh(1)	but not	usually	documented are
       labeled with `(u)'.

   Argument list processing
       If the first argument (argument 0) to the shell is `-'  then  it	 is  a
       login shell.  A login shell can be also specified by invoking the shell
       with the	-l flag	as the only argument.

       The rest	of the flag arguments are interpreted as follows:

       -b  Forces a ``break'' from  option  processing,	 causing  any  further
	   shell arguments to be treated as non-option arguments.  The remain-
	   ing arguments will not be interpreted as shell options.   This  may
	   be used to pass options to a	shell script without confusion or pos-
	   sible subterfuge.  The shell	will not  run  a  set-user  ID	script
	   without this	option.

       -c  Commands  are  read	from  the  following  argument	(which must be
	   present, and	must be	a single  argument),  stored  in  the  command
	   shell  variable  for	 reference, and	executed.  Any remaining argu-
	   ments are placed in the argv	shell variable.

       -d  The shell loads the directory stack from  ~/.cshdirs	 as  described
	   under Startup and shutdown, whether or not it is a login shell. (+)

       -Dname[=value]
	   Sets	the environment	variable name to value.	(Domain/OS only) (+)

       -e  The shell exits if any invoked  command  terminates	abnormally  or
	   yields a non-zero exit status.

       -f  The	shell  does not	load any resource or startup files, or perform
	   any command hashing,	and thus starts	faster.

       -F  The shell uses fork(2) instead of vfork(2) to spawn processes. (+)

       -i  The shell is	interactive and	prompts	for its	top-level input,  even
	   if it appears to not	be a terminal.	Shells are interactive without
	   this	option if their	inputs and outputs are terminals.

       -l  The shell is	a login	shell.	Applicable only	if -l is the only flag
	   specified.

       -m  The	shell loads ~/.tcshrc even if it does not belong to the	effec-
	   tive	user.  Newer versions of su(1) can pass	-m to the shell. (+)

       -n  The shell parses commands but does not execute them.	 This aids  in
	   debugging shell scripts.

       -q  The shell accepts SIGQUIT (see Signal handling) and behaves when it
	   is used under a debugger.  Job control is disabled. (u)

       -s  Command input is taken from the standard input.

       -t  The shell reads and executes	a single line of input.	 A `\' may  be
	   used	 to  escape  the  newline at the end of	this line and continue
	   onto	another	line.

       -v  Sets	the verbose shell variable, so that command  input  is	echoed
	   after history substitution.

       -x  Sets	 the  echo shell variable, so that commands are	echoed immedi-
	   ately before	execution.

       -V  Sets	the verbose shell variable even	before executing ~/.tcshrc.

       -X  Is to -x as -V is to	-v.

       --help
	   Print a help	message	on the standard	output and exit. (+)

       --version
	   Print the version/platform/compilation options on the standard out-
	   put	and  exit.   This information is also contained	in the version
	   shell variable. (+)

       After processing	of flag	arguments, if arguments	remain but none	of the
       -c,  -i,	 -s,  or -t options were given,	the first argument is taken as
       the name	of a file of commands, or ``script'',  to  be  executed.   The
       shell opens this	file and saves its name	for possible resubstitution by
       `$0'.  Because many systems use either the standard version 6  or  ver-
       sion  7	shells whose shell scripts are not compatible with this	shell,
       the shell uses such a `standard'	shell to execute a script whose	 first
       character is not	a `#', i.e., that does not start with a	comment.

       Remaining arguments are placed in the argv shell	variable.

   Startup and shutdown
       A  login	 shell	begins	by  executing  commands	 from the system files
       /etc/csh.cshrc and /etc/csh.login.   It	then  executes	commands  from
       files  in  the  user's  home  directory:	 first	~/.tcshrc  (+)	or, if
       ~/.tcshrc is not	found, ~/.cshrc, then ~/.history (or the value of  the
       histfile	shell variable), then ~/.login,	and finally ~/.cshdirs (or the
       value of	 the  dirsfile	shell  variable)  (+).	 The  shell  may  read
       /etc/csh.login  before  instead	of  after /etc/csh.cshrc, and ~/.login
       before instead of after ~/.tcshrc or ~/.cshrc  and  ~/.history,	if  so
       compiled; see the version shell variable. (+)

       Non-login  shells read only /etc/csh.cshrc and ~/.tcshrc	or ~/.cshrc on
       startup.

       For examples of startup	files,	please	consult	 http://tcshrc.source-
       forge.net.

       Commands	 like  stty(1)	and  tset(1),  which need be run only once per
       login, usually go in one's ~/.login file.  Users	who need  to  use  the
       same  set  of  files with both csh(1) and tcsh can have only a ~/.cshrc
       which checks for	the existence of the tcsh shell	variable (q.v.)	before
       using  tcsh-specific  commands,	or  can	 have  both  a	~/.cshrc and a
       ~/.tcshrc which sources (see the	builtin	command) ~/.cshrc.   The  rest
       of  this	manual uses `~/.tcshrc'	to mean	`~/.tcshrc or, if ~/.tcshrc is
       not found, ~/.cshrc'.

       In the normal case, the shell begins reading commands from  the	termi-
       nal,  prompting with `> '.  (Processing of arguments and	the use	of the
       shell to	process	files containing command scripts are described later.)
       The  shell  repeatedly  reads  a	 line of command input,	breaks it into
       words, places it	on the command history list, parses  it	 and  executes
       each command in the line.

       One can log out by typing `^D' on an empty line,	`logout' or `login' or
       via the shell's autologout mechanism (see the  autologout  shell	 vari-
       able).  When a login shell terminates it	sets the logout	shell variable
       to `normal' or `automatic' as appropriate, then executes	commands  from
       the  files  /etc/csh.logout  and	 ~/.logout.  The shell may drop	DTR on
       logout if so compiled; see the version shell variable.

       The names of the	system login and logout	files vary from	system to sys-
       tem for compatibility with different csh(1) variants; see FILES.

   Editing
       We  first describe The command-line editor.  The	Completion and listing
       and Spelling correction sections	describe  two  sets  of	 functionality
       that  are  implemented  as  editor commands but which deserve their own
       treatment.  Finally, Editor commands lists  and	describes  the	editor
       commands	specific to the	shell and their	default	bindings.

   The command-line editor (+)
       Command-line  input  can	 be edited using key sequences much like those
       used in GNU Emacs or vi(1).  The	editor is active only  when  the  edit
       shell  variable	is  set, which it is by	default	in interactive shells.
       The bindkey builtin can display and change key  bindings.   Emacs-style
       key  bindings are used by default (unless the shell was compiled	other-
       wise; see the version shell variable), but bindkey can change  the  key
       bindings	to vi-style bindings en	masse.

       The  shell always binds the arrow keys (as defined in the TERMCAP envi-
       ronment variable) to

	   down	   down-history
	   up	   up-history
	   left	   backward-char
	   right   forward-char

       unless doing so would alter another single-character binding.  One  can
       set  the	 arrow	key escape sequences to	the empty string with settc to
       prevent these bindings.	The ANSI/VT100 sequences for  arrow  keys  are
       always bound.

       Other  key  bindings are, for the most part, what Emacs and vi(1) users
       would expect and	can easily be displayed	by bindkey,  so	 there	is  no
       need to list them here.	Likewise, bindkey can list the editor commands
       with a short description	of each.

       Note that editor	commands do not	have the same notion of	a ``word''  as
       does  the  shell.   The editor delimits words with any non-alphanumeric
       characters not in the shell variable wordchars, while the shell	recog-
       nizes  only whitespace and some of the characters with special meanings
       to it, listed under Lexical structure.

   Completion and listing (+)
       The shell is often able to complete words when given a unique abbrevia-
       tion.  Type part	of a word (for example `ls /usr/lost') and hit the tab
       key to run the complete-word editor command.  The shell	completes  the
       filename	 `/usr/lost'  to  `/usr/lost+found/', replacing	the incomplete
       word with the complete word in the input	buffer.	  (Note	 the  terminal
       `/';  completion	 adds  a `/' to	the end	of completed directories and a
       space to	the end	of other completed words, to speed typing and  provide
       a visual	indicator of successful	completion.  The addsuffix shell vari-
       able can	be unset to prevent this.)  If	no  match  is  found  (perhaps
       `/usr/lost+found' doesn't exist), the terminal bell rings.  If the word
       is already complete (perhaps there is a `/usr/lost' on your system,  or
       perhaps	you  were  thinking too	far ahead and typed the	whole thing) a
       `/' or space is added to	the end	if it isn't already there.

       Completion works	anywhere in the	line, not at just the  end;  completed
       text  pushes the	rest of	the line to the	right.	Completion in the mid-
       dle of a	word often results in leftover characters to the right of  the
       cursor that need	to be deleted.

       Commands	 and  variables	 can  be  completed in much the	same way.  For
       example,	typing `em[tab]' would complete	`em' to	`emacs'	if emacs  were
       the  only  command  on your system beginning with `em'.	Completion can
       find a command in any directory in path or if given  a  full  pathname.
       Typing  `echo  $ar[tab]'	 would	complete  `$ar'	to `$argv' if no other
       variable	began with `ar'.

       The shell parses	the input buffer to determine  whether	the  word  you
       want  to	 complete  should be completed as a filename, command or vari-
       able.  The first	word in	the buffer and the first word  following  `;',
       `|',  `|&',  `&&' or `||' is considered to be a command.	 A word	begin-
       ning with `$' is	considered to be a variable.  Anything else is a file-
       name.  An empty line is `completed' as a	filename.

       You  can	 list the possible completions of a word at any	time by	typing
       `^D' to run the delete-char-or-list-or-eof editor command.   The	 shell
       lists  the  possible completions	using the ls-F builtin (q.v.)  and re-
       prints the prompt and unfinished	command	line, for example:

	   > ls	/usr/l[^D]
	   lbin/       lib/	   local/      lost+found/
	   > ls	/usr/l

       If the autolist shell variable is set, the shell	 lists	the  remaining
       choices (if any)	whenever completion fails:

	   > set autolist
	   > nm	/usr/lib/libt[tab]
	   libtermcap.a@ libtermlib.a@
	   > nm	/usr/lib/libterm

       If autolist is set to `ambiguous', choices are listed only when comple-
       tion fails and adds no new characters to	the word being completed.

       A filename to be	completed can contain variables, your own  or  others'
       home  directories  abbreviated with `~' (see Filename substitution) and
       directory stack entries abbreviated with	`=' (see Directory stack  sub-
       stitution).  For	example,

	   > ls	~k[^D]
	   kahn	   kas	   kellogg
	   > ls	~ke[tab]
	   > ls	~kellogg/

       or

	   > set local = /usr/local
	   > ls	$lo[tab]
	   > ls	$local/[^D]
	   bin/	etc/ lib/ man/ src/
	   > ls	$local/

       Note  that  variables  can also be expanded explicitly with the expand-
       variables editor	command.

       delete-char-or-list-or-eof lists	at only	the end	of the	line;  in  the
       middle  of  a  line it deletes the character under the cursor and on an
       empty line it logs one out or,  if  ignoreeof  is  set,	does  nothing.
       `M-^D', bound to	the editor command list-choices, lists completion pos-
       sibilities anywhere on a	line, and list-choices	(or  any  one  of  the
       related	editor	commands that do or don't delete, list and/or log out,
       listed under delete-char-or-list-or-eof)	can be bound to	`^D' with  the
       bindkey builtin command if so desired.

       The complete-word-fwd and complete-word-back editor commands (not bound
       to any keys by default) can be used to cycle up and  down  through  the
       list  of	possible completions, replacing	the current word with the next
       or previous word	in the list.

       The shell variable fignore can be set to	 a  list  of  suffixes	to  be
       ignored by completion.  Consider	the following:

	   > ls
	   Makefile	   condiments.h~   main.o	   side.c
	   README	   main.c	   meal		   side.o
	   condiments.h	   main.c~
	   > set fignore = (.o \~)
	   > emacs ma[^D]
	   main.c   main.c~  main.o
	   > emacs ma[tab]
	   > emacs main.c

       `main.c~'  and  `main.o'	 are  ignored by completion (but not listing),
       because they end	in suffixes in fignore.	 Note that a `\' was needed in
       front  of  `~'  to  prevent it from being expanded to home as described
       under Filename substitution.  fignore is	ignored	if only	one completion
       is possible.

       If  the	complete  shell	 variable  is  set to `enhance', completion 1)
       ignores case and	2) considers periods, hyphens  and  underscores	 (`.',
       `-'  and	 `_')  to be word separators and hyphens and underscores to be
       equivalent.  If you had the following files

	   comp.lang.c	    comp.lang.perl   comp.std.c++
	   comp.lang.c++    comp.std.c

       and typed `mail -f c.l.c[tab]', it  would  be  completed	 to  `mail  -f
       comp.lang.c',  and  ^D  would  list  `comp.lang.c' and `comp.lang.c++'.
       `mail -f	c..c++[^D]' would  list	 `comp.lang.c++'  and  `comp.std.c++'.
       Typing `rm a--file[^D]' in the following	directory

	   A_silly_file	   a-hyphenated-file	another_silly_file

       would  list  all	 three	files, because case is ignored and hyphens and
       underscores are equivalent.  Periods, however, are  not	equivalent  to
       hyphens or underscores.

       Completion  and	listing	are affected by	several	other shell variables:
       recexact	can be set to complete on the shortest possible	unique	match,
       even if more typing might result	in a longer match:

	   > ls
	   fodder   foo	     food     foonly
	   > set recexact
	   > rm	fo[tab]

       just beeps, because `fo'	could expand to	`fod' or `foo',	but if we type
       another `o',

	   > rm	foo[tab]
	   > rm	foo

       the completion completes	on `foo', even though `food' and `foonly' also
       match.	autoexpand can be set to run the expand-history	editor command
       before each completion attempt, autocorrect can be set to spelling-cor-
       rect  the  word	to  be completed (see Spelling correction) before each
       completion attempt and correct can be set to complete commands automat-
       ically  after  one hits `return'.  matchbeep can	be set to make comple-
       tion beep or not	beep in	a variety of situations, and nobeep can	be set
       to  never  beep	at  all.   nostat  can be set to a list	of directories
       and/or patterns that match directories to prevent the completion	mecha-
       nism from stat(2)ing those directories.	listmax	and listmaxrows	can be
       set to limit the	number of  items  and  rows  (respectively)  that  are
       listed  without asking first.  recognize_only_executables can be	set to
       make the	shell list only	executables when listing commands, but	it  is
       quite slow.

       Finally,	the complete builtin command can be used to tell the shell how
       to complete words other than filenames, commands	and  variables.	  Com-
       pletion	and listing do not work	on glob-patterns (see Filename substi-
       tution),	but the	list-glob  and	expand-glob  editor  commands  perform
       equivalent functions for	glob-patterns.

   Spelling correction (+)
       The shell can sometimes correct the spelling of filenames, commands and
       variable	names as well as completing and	listing	them.

       Individual words	can be spelling-corrected with the  spell-word	editor
       command (usually	bound to M-s and M-S) and the entire input buffer with
       spell-line (usually bound to M-$).  The correct shell variable  can  be
       set to `cmd' to correct the command name	or `all' to correct the	entire
       line each time return is	typed, and autocorrect can be set  to  correct
       the word	to be completed	before each completion attempt.

       When  spelling correction is invoked in any of these ways and the shell
       thinks that any part of the command line	is misspelled, it prompts with
       the corrected line:

	   > set correct = cmd
	   > lz	/usr/bin
	   CORRECT>ls /usr/bin (y|n|e|a)?

       One can answer `y' or space to execute the corrected line, `e' to leave
       the uncorrected command in the input buffer, `a'	to abort  the  command
       as if `^C' had been hit,	and anything else to execute the original line
       unchanged.

       Spelling	correction recognizes user-defined completions (see  the  com-
       plete  builtin  command).   If  an input	word in	a position for which a
       completion is defined resembles a word in the completion	list, spelling
       correction  registers  a	 misspelling and suggests the latter word as a
       correction.  However, if	the input word does not	match any of the  pos-
       sible  completions for that position, spelling correction does not reg-
       ister a misspelling.

       Like completion,	spelling correction works anywhere in the line,	 push-
       ing  the	rest of	the line to the	right and possibly leaving extra char-
       acters to the right of the cursor.

       Beware: spelling	correction is not  guaranteed  to  work	 the  way  one
       intends,	 and  is  provided mostly as an	experimental feature.  Sugges-
       tions and improvements are welcome.

   Editor commands (+)
       `bindkey' lists	key  bindings  and  `bindkey  -l'  lists  and  briefly
       describes  editor  commands.  Only new or especially interesting	editor
       commands	are described here.  See emacs(1) and vi(1)  for  descriptions
       of each editor's	key bindings.

       The  character  or characters to	which each command is bound by default
       is given	in parentheses.	 `^character' means a  control	character  and
       `M-character'  a	meta character,	typed as escape-character on terminals
       without a meta key.  Case counts, but commands that are bound  to  let-
       ters by default are bound to both lower-	and uppercase letters for con-
       venience.

       complete-word (tab)
	       Completes a word	as described under Completion and listing.

       complete-word-back (not bound)
	       Like complete-word-fwd, but steps up from the end of the	 list.

       complete-word-fwd (not bound)
	       Replaces	 the  current  word with the first word	in the list of
	       possible	completions.  May be repeated to step down through the
	       list.   At the end of the list, beeps and reverts to the	incom-
	       plete word.

       complete-word-raw (^X-tab)
	       Like complete-word, but ignores user-defined completions.

       copy-prev-word (M-^_)
	       Copies the previous word	in the current	line  into  the	 input
	       buffer.	See also insert-last-word.

       dabbrev-expand (M-/)
	       Expands	the  current word to the most recent preceding one for
	       which the current is a leading substring, wrapping  around  the
	       history	list  (once)  if  necessary.  Repeating	dabbrev-expand
	       without any intervening typing changes  to  the	next  previous
	       word etc., skipping identical matches much like history-search-
	       backward	does.

       delete-char (not	bound)
	       Deletes the character under the cursor.	See also  delete-char-
	       or-list-or-eof.

       delete-char-or-eof (not bound)
	       Does  delete-char  if  there is a character under the cursor or
	       end-of-file on an empty line.  See also delete-char-or-list-or-
	       eof.

       delete-char-or-list (not	bound)
	       Does  delete-char  if  there is a character under the cursor or
	       list-choices at the end of the line.  See also  delete-char-or-
	       list-or-eof.

       delete-char-or-list-or-eof (^D)
	       Does  delete-char  if  there  is	 a character under the cursor,
	       list-choices at the end of the line or end-of-file on an	 empty
	       line.  See also those three commands, each of which does	only a
	       single action, and delete-char-or-eof, delete-char-or-list  and
	       list-or-eof,  each  of  which  does  a different	two out	of the
	       three.

       down-history (down-arrow, ^N)
	       Like up-history,	but steps down,	stopping at the	original input
	       line.

       end-of-file (not	bound)
	       Signals	an  end	 of file, causing the shell to exit unless the
	       ignoreeof shell variable	(q.v.) is set to  prevent  this.   See
	       also delete-char-or-list-or-eof.

       expand-history (M-space)
	       Expands history substitutions in	the current word.  See History
	       substitution.  See also magic-space, toggle-literal-history and
	       the autoexpand shell variable.

       expand-glob (^X-*)
	       Expands	the glob-pattern to the	left of	the cursor.  See File-
	       name substitution.

       expand-line (not	bound)
	       Like expand-history, but	expands	history	substitutions in  each
	       word in the input buffer,

       expand-variables	(^X-$)
	       Expands	the  variable to the left of the cursor.  See Variable
	       substitution.

       history-search-backward (M-p, M-P)
	       Searches	backwards through  the	history	 list  for  a  command
	       beginning  with	the current contents of	the input buffer up to
	       the cursor and copies it	into the  input	 buffer.   The	search
	       string  may  be a glob-pattern (see Filename substitution) con-
	       taining `*', `?', `[]' or `{}'.	 up-history  and  down-history
	       will  proceed  from  the	appropriate point in the history list.
	       Emacs mode only.	 See also history-search-forward and i-search-
	       back.

       history-search-forward (M-n, M-N)
	       Like history-search-backward, but searches forward.

       i-search-back (not bound)
	       Searches	 backward  like	 history-search-backward,  copies  the
	       first match into	the input buffer with the cursor positioned at
	       the  end	of the pattern,	and prompts with `bck: ' and the first
	       match.  Additional  characters  may  be	typed  to  extend  the
	       search,	i-search-back  may be typed to continue	searching with
	       the same	pattern, wrapping around the history  list  if	neces-
	       sary,  (i-search-back  must  be bound to	a single character for
	       this to work) or	one of the following special characters	may be
	       typed:

		   ^W	   Appends  the	 rest  of the word under the cursor to
			   the search pattern.
		   delete (or any character bound to backward-delete-char)
			   Undoes the effect of	the last character  typed  and
			   deletes  a  character  from	the  search pattern if
			   appropriate.
		   ^G	   If the previous search was successful,  aborts  the
			   entire  search.  If not, goes back to the last suc-
			   cessful search.
		   escape  Ends	the search, leaving the	current	 line  in  the
			   input buffer.

	       Any other character not bound to	self-insert-command terminates
	       the search, leaving the current line in the input  buffer,  and
	       is then interpreted as normal input.  In	particular, a carriage
	       return causes the current line  to  be  executed.   Emacs  mode
	       only.  See also i-search-fwd and	history-search-backward.

       i-search-fwd (not bound)
	       Like i-search-back, but searches	forward.

       insert-last-word	(M-_)
	       Inserts	the  last  word	of the previous	input line (`!$') into
	       the input buffer.  See also copy-prev-word.

       list-choices (M-^D)
	       Lists completion	possibilities as  described  under  Completion
	       and  listing.   See  also  delete-char-or-list-or-eof and list-
	       choices-raw.

       list-choices-raw	(^X-^D)
	       Like list-choices, but ignores user-defined completions.

       list-glob (^X-g,	^X-G)
	       Lists (via the ls-F builtin) matches to the  glob-pattern  (see
	       Filename	substitution) to the left of the cursor.

       list-or-eof (not	bound)
	       Does  list-choices  or  end-of-file on an empty line.  See also
	       delete-char-or-list-or-eof.

       magic-space (not	bound)
	       Expands history substitutions in	the current line, like expand-
	       history,	 and  inserts  a space.	 magic-space is	designed to be
	       bound to	the space bar, but is not bound	by default.

       normalize-command (^X-?)
	       Searches	for the	current	word in	PATH  and,  if	it  is	found,
	       replaces	 it  with  the	full  path to the executable.  Special
	       characters are quoted.  Aliases are  expanded  and  quoted  but
	       commands	 within	 aliases are not.  This	command	is useful with
	       commands	that take commands as arguments, e.g., `dbx'  and  `sh
	       -x'.

       normalize-path (^X-n, ^X-N)
	       Expands	the  current word as described under the `expand' set-
	       ting of the symlinks shell variable.

       overwrite-mode (unbound)
	       Toggles between input and overwrite modes.

       run-fg-editor (M-^Z)
	       Saves the current input line and	looks for a stopped job	with a
	       name  equal  to the last	component of the file name part	of the
	       EDITOR or VISUAL	environment variables, or, if neither is  set,
	       `ed'  or	 `vi'.	 If such a job is found, it is restarted as if
	       `fg %job' had been typed.  This is  used	 to  toggle  back  and
	       forth between an	editor and the shell easily.  Some people bind
	       this command to `^Z' so they can	do this	even more easily.

       run-help	(M-h, M-H)
	       Searches	for documentation on the current  command,  using  the
	       same  notion  of	 `current command' as the completion routines,
	       and prints it.  There is	no way to use  a  pager;  run-help  is
	       designed	 for  short help files.	 If the	special	alias helpcom-
	       mand is defined,	it is run with the  command  name  as  a  sole
	       argument.   Else,  documentation	should be in a file named com-
	       mand.help, command.1, command.6,	command.8  or  command,	 which
	       should  be  in one of the directories listed in the HPATH envi-
	       ronment variable.  If there is more than	one help file only the
	       first is	printed.

       self-insert-command (text characters)
	       In  insert mode (the default), inserts the typed	character into
	       the input line after the	character under	the cursor.  In	 over-
	       write  mode,  replaces  the character under the cursor with the
	       typed character.	 The input mode	is normally preserved  between
	       lines,  but the inputmode shell variable	can be set to `insert'
	       or `overwrite' to put the editor	in that	mode at	the  beginning
	       of each line.  See also overwrite-mode.

       sequence-lead-in	(arrow prefix, meta prefix, ^X)
	       Indicates that the following characters are part	of a multi-key
	       sequence.  Binding a command to	a  multi-key  sequence	really
	       creates	two  bindings: the first character to sequence-lead-in
	       and the whole sequence to the command.  All sequences beginning
	       with  a	character  bound  to  sequence-lead-in are effectively
	       bound to	undefined-key unless bound to another command.

       spell-line (M-$)
	       Attempts	to correct the spelling	of  each  word	in  the	 input
	       buffer,	like spell-word, but ignores words whose first charac-
	       ter is one of `-', `!', `^' or `%', or which contain  `\',  `*'
	       or  `?',	to avoid problems with switches, substitutions and the
	       like.  See Spelling correction.

       spell-word (M-s,	M-S)
	       Attempts	to  correct  the  spelling  of	the  current  word  as
	       described  under	Spelling correction.  Checks each component of
	       a word which appears to be a pathname.

       toggle-literal-history (M-r, M-R)
	       Expands or  `unexpands'	history	 substitutions	in  the	 input
	       buffer.	See also expand-history	and the	autoexpand shell vari-
	       able.

       undefined-key (any unbound key)
	       Beeps.

       up-history (up-arrow, ^P)
	       Copies the previous entry in the	history	list  into  the	 input
	       buffer.	If histlit is set, uses	the literal form of the	entry.
	       May be repeated to step up through the history  list,  stopping
	       at the top.

       vi-search-back (?)
	       Prompts	with `?' for a search string (which may	be a glob-pat-
	       tern, as	with history-search-backward),	searches  for  it  and
	       copies it into the input	buffer.	 The bell rings	if no match is
	       found.  Hitting return ends the	search	and  leaves  the  last
	       match  in the input buffer.  Hitting escape ends	the search and
	       executes	the match.  vi mode only.

       vi-search-fwd (/)
	       Like vi-search-back, but	searches forward.

       which-command (M-?)
	       Does a which (see the description of the	 builtin  command)  on
	       the first word of the input buffer.

       yank-pop	(M-y)
	       When  executed  immediately  after  a yank or another yank-pop,
	       replaces	the yanked string with the next	previous  string  from
	       the  killring.  This  also has the effect of rotating the kill-
	       ring, such  that	 this  string  will  be	 considered  the  most
	       recently	 killed	 by  a	later yank command. Repeating yank-pop
	       will cycle through the killring any number of times.

   Lexical structure
       The shell splits	input lines into words at blanks and tabs.   The  spe-
       cial  characters	 `&', `|', `;',	`<', `>', `(', and `)' and the doubled
       characters `&&',	`||', `<<' and `>>' are	always separate	words, whether
       or not they are surrounded by whitespace.

       When the	shell's	input is not a terminal, the character `#' is taken to
       begin a comment.	 Each `#' and the rest of the input line on  which  it
       appears is discarded before further parsing.

       A  special  character  (including a blank or tab) may be	prevented from
       having its special meaning, and possibly	made part of another word,  by
       preceding  it  with  a backslash	(`\') or enclosing it in single	(`''),
       double (`"') or backward	(``') quotes.  When  not  otherwise  quoted  a
       newline	preceded  by a `\' is equivalent to a blank, but inside	quotes
       this sequence results in	a newline.

       Furthermore, all	Substitutions (see below) except History  substitution
       can  be	prevented  by  enclosing  the strings (or parts	of strings) in
       which they appear with single quotes or by quoting the crucial  charac-
       ter(s) (e.g., `$' or ``'	for Variable substitution or Command substitu-
       tion respectively) with `\'.   (Alias  substitution  is	no  exception:
       quoting	in any way any character of a word for which an	alias has been
       defined prevents	substitution of	the alias.  The	usual way  of  quoting
       an  alias  is  to precede it with a backslash.) History substitution is
       prevented by backslashes	but not	by single quotes.  Strings quoted with
       double  or  backward  quotes  undergo Variable substitution and Command
       substitution, but other substitutions are prevented.

       Text inside single or double quotes becomes a single word (or  part  of
       one).   Metacharacters  in these	strings, including blanks and tabs, do
       not form	separate words.	 Only in one special case (see Command substi-
       tution  below)  can a double-quoted string yield	parts of more than one
       word; single-quoted strings never do.   Backward	 quotes	 are  special:
       they  signal Command substitution (q.v.), which may result in more than
       one word.

       Quoting complex strings,	particularly strings which themselves  contain
       quoting characters, can be confusing.  Remember that quotes need	not be
       used as they are	in human writing!  It may be easier to	quote  not  an
       entire  string,	but only those parts of	the string which need quoting,
       using different types of	quoting	to do so if appropriate.

       The backslash_quote shell variable (q.v.) can  be  set  to  make	 back-
       slashes	always	quote  `\',  `'',  and `"'.  (+) This may make complex
       quoting tasks easier, but it can	cause syntax errors in csh(1) scripts.

   Substitutions
       We  now	describe the various transformations the shell performs	on the
       input in	the order in which they	occur.	We note	in  passing  the  data
       structures  involved  and the commands and variables which affect them.
       Remember	that substitutions can be prevented by	quoting	 as  described
       under Lexical structure.

   History substitution
       Each  command,  or  ``event'',  input from the terminal is saved	in the
       history list.  The previous command is always saved,  and  the  history
       shell  variable can be set to a number to save that many	commands.  The
       histdup shell variable can be set to not	save duplicate events or  con-
       secutive	duplicate events.

       Saved  commands	are  numbered sequentially from	1 and stamped with the
       time.  It is not	usually	necessary to use event numbers,	but  the  cur-
       rent  event  number can be made part of the prompt by placing an	`!' in
       the prompt shell	variable.

       The shell actually saves	history	in expanded and	 literal  (unexpanded)
       forms.  If the histlit shell variable is	set, commands that display and
       store history use the literal form.

       The history builtin command can print, store in	a  file,  restore  and
       clear the history list at any time, and the savehist and	histfile shell
       variables can be	can be set to store the	history	list automatically  on
       logout and restore it on	login.

       History	substitutions  introduce  words	from the history list into the
       input stream, 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 and a  high  degree  of	confi-
       dence.

       History	substitutions  begin  with  the	character `!'.	They may begin
       anywhere	in the input stream, but they do not nest.   The  `!'  may  be
       preceded	 by  a	`\' to prevent its special meaning; for	convenience, a
       `!' is passed unchanged when it is followed by a	blank,	tab,  newline,
       `=' or `('.  History substitutions also occur when an input line	begins
       with `^'.  This special abbreviation  will  be  described  later.   The
       characters  used	 to  signal  history substitution (`!' and `^')	can be
       changed by setting the histchars	shell variable.	 Any input line	 which
       contains	a history substitution is printed before it is executed.

       A history substitution may have an ``event specification'', which indi-
       cates the event from which words	are to be  taken,  a  ``word  designa-
       tor'',  which  selects particular words from the	chosen event, and/or a
       ``modifier'', which manipulates the selected words.

       An event	specification can be

	   n	   A number, referring to a particular event
	   -n	   An offset, referring	to the	event  n  before  the  current
		   event
	   #	   The	current	 event.	  This	should	be  used  carefully in
		   csh(1), where there is no check for recursion.  tcsh	allows
		   10 levels of	recursion.  (+)
	   !	   The previous	event (equivalent to `-1')
	   s	   The	most  recent  event  whose  first word begins with the
		   string s
	   ?s?	   The most recent event which contains	 the  string  s.   The
		   second  `?' can be omitted if it is immediately followed by
		   a newline.

       For example, consider this bit of someone's history list:

	    9  8:30    nroff -man wumpus.man
	   10  8:31    cp wumpus.man wumpus.man.old
	   11  8:36    vi wumpus.man
	   12  8:37    diff wumpus.man.old wumpus.man

       The commands are	shown with their event numbers and time	 stamps.   The
       current	event,	which we haven't typed in yet, is event	13.  `!11' and
       `!-2' refer to event 11.	 `!!' refers to	the previous event, 12.	  `!!'
       can  be	abbreviated  `!'  if  it  is followed by `:' (`:' is described
       below).	`!n' refers to event 9,	which begins with `n'.	`!?old?'  also
       refers  to event	12, which contains `old'.  Without word	designators or
       modifiers history references simply expand to the entire	event,	so  we
       might  type  `!cp'  to redo the copy command or `!!|more' if the	`diff'
       output scrolled off the top of the screen.

       History references may be insulated  from  the  surrounding  text  with
       braces  if  necessary.	For  example, `!vdoc' would look for a command
       beginning with  `vdoc',	and,  in  this	example,  not  find  one,  but
       `!{v}doc'  would	 expand	 unambiguously to `vi wumpus.mandoc'.  Even in
       braces, history substitutions do	not nest.

       (+) While csh(1)	expands, for example, `!3d' to event 3 with the	letter
       `d'  appended  to  it, tcsh expands it to the last event	beginning with
       `3d'; only completely numeric arguments are treated as  event  numbers.
       This  makes  it	possible  to recall events beginning with numbers.  To
       expand `!3d' as in csh(1) say `!{3}d'.

       To select words from an event we	can follow the event specification  by
       a  `:'  and  a designator for the desired words.	 The words of an input
       line are	numbered from 0, the first (usually command) word being	0, the
       second  word (first argument) being 1, etc.  The	basic word designators
       are:

	   0	   The first (command) word
	   n	   The nth argument
	   ^	   The first argument, equivalent to `1'
	   $	   The last argument
	   %	   The word matched by an ?s? search
	   x-y	   A range of words
	   -y	   Equivalent to `0-y'
	   *	   Equivalent to `^-$',	but returns nothing if the event  con-
		   tains only 1	word
	   x*	   Equivalent to `x-$'
	   x-	   Equivalent to `x*', but omitting the	last word (`$')

       Selected	 words	are inserted into the command line separated by	single
       blanks.	For example, the `diff'	command	in the previous	example	 might
       have been typed as `diff	!!:1.old !!:1' (using `:1' to select the first
       argument	from the previous event) or `diff !-2:2	!-2:1' to  select  and
       swap  the arguments from	the `cp' command.  If we didn't	care about the
       order of	the `diff' we might have said `diff !-2:1-2' or	 simply	 `diff
       !-2:*'.	 The  `cp'  command  might  have  been	written	`cp wumpus.man
       !#:1.old', using	`#' to refer to	the current event.  `!n:-  hurkle.man'
       would  reuse the	first two words	from the `nroff' command to say	`nroff
       -man hurkle.man'.

       The `:' separating the event specification from the word	designator can
       be omitted if the argument selector begins with a `^', `$', `*',	`%' or
       `-'.  For example, our `diff' command might  have  been	`diff  !!^.old
       !!^'  or, equivalently, `diff !!$.old !!$'.  However, if	`!!' is	abbre-
       viated `!', an argument selector	beginning with `-' will	be interpreted
       as an event specification.

       A  history reference may	have a word designator but no event specifica-
       tion.  It then references the previous command.	Continuing our	`diff'
       example,	 we  could  have  said	simply `diff !^.old !^'	or, to get the
       arguments in the	opposite order,	just `diff !*'.

       The word	or words in a history reference	 can  be  edited,  or  ``modi-
       fied'',	by following it	with one or more modifiers, each preceded by a
       `:':

	   h	   Remove a trailing pathname component, leaving the head.
	   t	   Remove all leading pathname components, leaving the tail.
	   r	   Remove a filename extension `.xxx', leaving the root	 name.
	   e	   Remove all but the extension.
	   u	   Uppercase the first lowercase letter.
	   l	   Lowercase the first uppercase letter.
	   s/l/r/  Substitute  l  for  r.   l is simply	a string like r, not a
		   regular expression as in the	eponymous ed(1)	command.   Any
		   character  may  be used as the delimiter in place of	`/'; a
		   `\' can be used to quote the	delimiter inside l and r.  The
		   character  `&'  in  the r is	replaced by l; `\' also	quotes
		   `&'.	 If l is empty (``''), the l from a previous substitu-
		   tion	 or  the  s  from a previous search or event number in
		   event specification is used.	 The trailing delimiter	may be
		   omitted if it is immediately	followed by a newline.
	   &	   Repeat the previous substitution.
	   g	   Apply the following modifier	once to	each word.
	   a (+)   Apply the following modifier	as many	times as possible to a
		   single word.	 `a' and `g' can be used together to  apply  a
		   modifier  globally.	 With  the `s' modifier, only the pat-
		   terns contained in the original word	are  substituted,  not
		   patterns that contain any substitution result.
	   p	   Print the new command line but do not execute it.
	   q	   Quote  the  substituted words, preventing further substitu-
		   tions.
	   x	   Like	q, but break into words	at blanks, tabs	and  newlines.

       Modifiers  are applied to only the first	modifiable word	(unless	`g' is
       used).  It is an	error for no word to be	modifiable.

       For example, the	`diff' command might have been written as  `diff  wum-
       pus.man.old !#^:r', using `:r' to remove	`.old' from the	first argument
       on the same line	(`!#^').  We could say `echo hello  out	 there',  then
       `echo  !*:u' to capitalize `hello', `echo !*:au'	to say it out loud, or
       `echo !*:agu' to	really shout.  We might	follow `mail -s	"I  forgot  my
       password"  rot'	with  `!:s/rot/root' to	correct	the spelling of	`root'
       (but see	Spelling correction for	a different approach).

       There is	a special abbreviation for substitutions.  `^',	when it	is the
       first  character	 on  an	 input line, is	equivalent to `!:s^'.  Thus we
       might have said `^rot^root' to make the spelling	correction in the pre-
       vious  example.	 This  is the only history substitution	which does not
       explicitly begin	with `!'.

       (+) In csh as such, only	one modifier may be applied to each history or
       variable	expansion.  In tcsh, more than one may be used,	for example

	   % mv	wumpus.man /usr/man/man1/wumpus.1
	   % man !$:t:r
	   man wumpus

       In csh, the result would	be `wumpus.1:r'.  A substitution followed by a
       colon may need to be insulated from it with braces:

	   > mv	a.out /usr/games/wumpus
	   > setenv PATH !$:h:$PATH
	   Bad ! modifier: $.
	   > setenv PATH !{-2$:h}:$PATH
	   setenv PATH /usr/games:/bin:/usr/bin:.

       The first attempt would succeed in csh but fails	in tcsh, because  tcsh
       expects another modifier	after the second colon rather than `$'.

       Finally,	 history can be	accessed through the editor as well as through
       the substitutions just described.  The up- and  down-history,  history-
       search-backward	and  -forward,	i-search-back and -fwd,	vi-search-back
       and -fwd, copy-prev-word	and insert-last-word  editor  commands	search
       for  events  in	the  history list and copy them	into the input buffer.
       The toggle-literal-history editor command switches between the expanded
       and literal forms of history lines in the input buffer.	expand-history
       and expand-line expand history substitutions in the current word	and in
       the entire input	buffer respectively.

   Alias substitution
       The  shell  maintains  a	 list  of  aliases which can be	set, unset and
       printed by the alias and	unalias	commands.  After  a  command  line  is
       parsed  into simple commands (see Commands) the first word of each com-
       mand, left-to-right, is checked to see if it has	an alias.  If so,  the
       first  word  is replaced	by the alias.  If the alias contains a history
       reference, it undergoes History substitution (q.v.) as though the orig-
       inal  command were the previous input line.  If the alias does not con-
       tain a history reference, the argument list is left untouched.

       Thus if the alias for `ls' were `ls -l' the  command  `ls  /usr'	 would
       become  `ls -l /usr', the argument list here being undisturbed.	If the
       alias for `lookup' were `grep !^	/etc/passwd' then `lookup bill'	 would
       become  `grep  bill  /etc/passwd'.   Aliases  can  be used to introduce
       parser metasyntax.  For example,	`alias print 'pr \!* | lpr'' defines a
       ``command'' (`print') which pr(1)s its arguments	to the line printer.

       Alias  substitution is repeated until the first word of the command has
       no alias.  If an	alias substitution does	not change the first word  (as
       in  the previous	example) it is flagged to prevent a loop.  Other loops
       are detected and	cause an error.

       Some aliases are	referred to by the shell; see Special aliases.

   Variable substitution
       The shell maintains a list of variables,	each of	which has as  value  a
       list  of	zero or	more words.  The values	of shell variables can be dis-
       played and changed with the set and unset commands.  The	 system	 main-
       tains  its  own	list  of ``environment'' variables.  These can be dis-
       played and changed with printenv, setenv	and unsetenv.

       (+) Variables may be made read-only with	 `set  -r'  (q.v.)   Read-only
       variables  may not be modified or unset;	attempting to do so will cause
       an error.  Once made read-only, a variable cannot be made writable,  so
       `set  -r' should	be used	with caution.  Environment variables cannot be
       made read-only.

       Some variables are set  by  the	shell  or  referred  to	 by  it.   For
       instance,  the  argv variable is	an image of the	shell's	argument list,
       and words of this variable's value are referred	to  in	special	 ways.
       Some  of	 the variables referred	to by the shell	are toggles; the shell
       does not	care what their	value is, only whether they are	 set  or  not.
       For  instance,  the  verbose  variable is a toggle which	causes command
       input to	be echoed.  The	-v command line	 option	 sets  this  variable.
       Special	shell  variables  lists	all variables which are	referred to by
       the shell.

       Other operations	treat variables	numerically.  The `@' command  permits
       numeric calculations to be performed and	the result assigned to a vari-
       able.  Variable values are, however, always  represented	 as  (zero  or
       more) strings.  For the purposes	of numeric operations, the null	string
       is considered to	be zero, and the second	and subsequent words of	multi-
       word values are ignored.

       After  the input	line is	aliased	and parsed, and	before each command is
       executed, variable substitution is performed keyed by  `$'  characters.
       This  expansion can be prevented	by preceding the `$' with a `\'	except
       within `"'s where it always occurs, and	within	`''s  where  it	 never
       occurs.	 Strings quoted	by ``' are interpreted later (see Command sub-
       stitution below)	so `$' substitution does not occur there until	later,
       if  at  all.  A `$' is passed unchanged if followed by a	blank, tab, or
       end-of-line.

       Input/output redirections are recognized	before variable	expansion, and
       are  variable  expanded	separately.   Otherwise,  the command name and
       entire argument list are	expanded together.  It is  thus	 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 vari-
       able substitution may eventually	be command and	filename  substituted.
       Within  `"',  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 blanks.  When the `:q' modifier is	applied	to a substitu-
       tion the	variable will expand to	multiple words with  each  word	 sepa-
       rated  by  a blank and quoted to	prevent	later command or filename sub-
       stitution.

       The following metasequences are provided	for introducing	variable  val-
       ues into	the shell input.  Except as noted, it is an error to reference
       a variable which	is not set.

       $name
       ${name} Substitutes the words of	the value of variable name, each sepa-
	       rated  by a blank.  Braces insulate name	from following charac-
	       ters which would	otherwise be part of it.  Shell	variables have
	       names  consisting of letters and	digits starting	with a letter.
	       The underscore character	is considered a	letter.	  If  name  is
	       not  a shell variable, but is set in the	environment, then that
	       value is	returned (but some of the other	forms given below  are
	       not available in	this case).
       $name[selector]
       ${name[selector]}
	       Substitutes  only  the  selected	 words from the	value of name.
	       The selector is subjected to `$'	substitution and  may  consist
	       of  a  single  number  or  two numbers separated	by a `-'.  The
	       first word of a variable's 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
	       selector	`*' selects all	words.	It is not an error for a range
	       to be empty if the second argument is omitted or	in range.
       $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', which is equivalent to `$argv[*]'.

       The  `:'	 modifiers  described  under  History substitution, except for
       `:p', can be applied to the substitutions above.	 More than one may  be
       used.   (+)  Braces  may	 be needed to insulate a variable substitution
       from a literal colon just as with History substitution (q.v.); any mod-
       ifiers must appear within the braces.

       The following substitutions can not be modified with `:'	modifiers.

       $?name
       ${?name}
	       Substitutes the string `1' if name is set, `0' if it is not.
       $?0     Substitutes  `1'	if the current input filename is known,	`0' if
	       it is not.  Always `0' in interactive shells.
       $#name
       ${#name}
	       Substitutes the number of words in name.
       $#      Equivalent to `$#argv'.	(+)
       $%name
       ${%name}
	       Substitutes the number of characters in name.  (+)
       $%number
       ${%number}
	       Substitutes the number of characters in $argv[number].  (+)
       $?      Equivalent to `$status'.	 (+)
       $$      Substitutes the (decimal) process number	of the (parent)	shell.
       $!      Substitutes the (decimal) process number	of the last background
	       process started by this shell.  (+)
       $_      Substitutes the command line of the last	command	executed.  (+)
       $<      Substitutes  a  line  from  the standard	input, with no further
	       interpretation thereafter.  It can be used  to  read  from  the
	       keyboard	in a shell script.  (+)	While csh always quotes	$<, as
	       if it were equivalent to	`$<:q',	tcsh does  not.	  Furthermore,
	       when  tcsh  is waiting for a line to be typed the user may type
	       an interrupt to interrupt the sequence into which the  line  is
	       to be substituted, but csh does not allow this.

       The  editor  command expand-variables, normally bound to	`^X-$',	can be
       used to interactively expand individual variables.

   Command, filename and directory stack substitution
       The remaining substitutions are applied selectively to the arguments of
       builtin	commands.   This  means	that portions of expressions which are
       not evaluated are not subjected	to  these  expansions.	 For  commands
       which  are  not	internal to the	shell, the command name	is substituted
       separately from the argument list.  This	occurs very late, after	input-
       output redirection is performed,	and in a child of the main shell.

   Command substitution
       Command	substitution  is  indicated by a command enclosed in ``'.  The
       output from such	a command is broken into  separate  words  at  blanks,
       tabs  and  newlines, and	null words are discarded.  The output is vari-
       able and	command	substituted and	put in place of	the original string.

       Command substitutions inside double  quotes  (`"')  retain  blanks  and
       tabs; only newlines force new words.  The single	final newline does not
       force a new word	in any case.  It is thus possible for a	 command  sub-
       stitution  to  yield only part of a word, even if the command outputs a
       complete	line.

       By default, the shell since version 6.12	replaces all newline and  car-
       riage  return characters	in the command by spaces.  If this is switched
       off by unsetting	csubstnonl, newlines separate commands as usual.

   Filename substitution
       If a word contains any of the characters	`*', `?', `[' or `{' or	begins
       with  the  character  `~'  it is	a candidate for	filename substitution,
       also known as ``globbing''.  This word is then regarded	as  a  pattern
       (``glob-pattern''),  and	replaced with an alphabetically	sorted list of
       file names which	match the pattern.

       In matching filenames, the character `.'	at the beginning of a filename
       or  immediately	following  a `/', as well as the character `/' must be
       matched explicitly.  The	character `*' matches any  string  of  charac-
       ters,  including	the null string.  The character	`?' matches any	single
       character.  The sequence	`[...]'	matches	 any  one  of  the  characters
       enclosed.   Within  `[...]',  a	pair  of  characters  separated	by `-'
       matches any character lexically between the two.

       (+) Some	glob-patterns can be negated: The  sequence  `[^...]'  matches
       any  single  character not specified by the characters and/or ranges of
       characters in the braces.

       An entire glob-pattern can also be negated with `^':

	   > echo *
	   bang	crash crunch ouch
	   > echo ^cr*
	   bang	ouch

       Glob-patterns which do not use `?', `*',	or `[]'	or which use  `{}'  or
       `~' (below) are not negated correctly.

       The  metanotation  `a{b,c,d}e' is a shorthand for `abe ace ade'.	 Left-
       to-right	order is preserved: `/usr/source/s1/{oldls,ls}.c'  expands  to
       `/usr/source/s1/oldls.c	/usr/source/s1/ls.c'.	The results of matches
       are  sorted  separately	at  a  low  level  to  preserve	 this	order:
       `../{memo,*box}'	 might expand to `../memo ../box ../mbox'.  (Note that
       `memo' was not sorted with the results of matching `*box'.)  It is  not
       an  error  when this construct expands to files which do	not exist, but
       it is possible to get an	error from a command  to  which	 the  expanded
       list  is	 passed.  This construct may be	nested.	 As a special case the
       words `{', `}' and `{}' are passed undisturbed.

       The character `~' at the	beginning of a filename	refers to home	direc-
       tories.	 Standing  alone,  i.e., `~', it expands to the	invoker's home
       directory as reflected in the value of the home shell  variable.	  When
       followed	by a name consisting of	letters, digits	and `-'	characters the
       shell searches for a user with that name	 and  substitutes  their  home
       directory;  thus	`~ken' might expand to `/usr/ken' and `~ken/chmach' to
       `/usr/ken/chmach'.  If the character `~'	is  followed  by  a  character
       other  than  a letter or	`/' or appears elsewhere than at the beginning
       of a word, it is	left undisturbed.   A  command	like  `setenv  MANPATH
       /usr/man:/usr/local/man:~/lib/man'  does	not, therefore,	do home	direc-
       tory substitution as one	might hope.

       It is an	error for a glob-pattern containing `*', `?', `[' or `~', with
       or without `^', not to match any	files.	However, only one pattern in a
       list of glob-patterns must match	a file (so that,  e.g.,	 `rm  *.a  *.c
       *.o'  would  fail  only if there	were no	files in the current directory
       ending in `.a', `.c', or	`.o'), and if the nonomatch shell variable  is
       set  a  pattern	(or  list  of  patterns) which matches nothing is left
       unchanged rather	than causing an	error.

       The noglob shell	variable can be	set to prevent filename	 substitution,
       and  the	 expand-glob  editor command, normally bound to	`^X-*',	can be
       used to interactively expand individual filename	substitutions.

   Directory stack substitution	(+)
       The directory stack is a	list of	directories, numbered from zero,  used
       by  the	pushd, popd and	dirs builtin commands (q.v.).  dirs can	print,
       store in	a file,	restore	and clear the directory	stack at any time, and
       the  savedirs  and  dirsfile  shell  variables  can be set to store the
       directory stack automatically on	logout and restore it on  login.   The
       dirstack	 shell variable	can be examined	to see the directory stack and
       set to put arbitrary directories	into the directory stack.

       The character `=' followed by one or more digits	expands	to an entry in
       the  directory stack.  The special case `=-' expands to the last	direc-
       tory in the stack.  For example,

	   > dirs -v
	   0	   /usr/bin
	   1	   /usr/spool/uucp
	   2	   /usr/accts/sys
	   > echo =1
	   /usr/spool/uucp
	   > echo =0/calendar
	   /usr/bin/calendar
	   > echo =-
	   /usr/accts/sys

       The noglob and nonomatch	shell variables	 and  the  expand-glob	editor
       command apply to	directory stack	as well	as filename substitutions.

   Other substitutions (+)
       There   are  several  more  transformations  involving  filenames,  not
       strictly	related	to the above but mentioned here	for completeness.  Any
       filename	 may  be  expanded  to	a full path when the symlinks variable
       (q.v.) is set to	`expand'.  Quoting prevents this  expansion,  and  the
       normalize-path editor command does it on	demand.	 The normalize-command
       editor command expands commands in PATH	into  full  paths  on  demand.
       Finally,	 cd  and  pushd	 interpret  `-'	 as  the old working directory
       (equivalent to the shell	variable owd).	This is	not a substitution  at
       all,  but  an abbreviation recognized by	only those commands.  Nonethe-
       less, it	too can	be prevented by	quoting.

   Commands
       The next	three sections describe	how the	shell  executes	 commands  and
       deals with their	input and output.

   Simple commands, pipelines and sequences
       A  simple  command is a sequence	of words, the first of which specifies
       the command to be executed.  A series of	simple commands	joined by  `|'
       characters  forms a pipeline.  The output of each command in a pipeline
       is connected to the input of the	next.

       Simple commands and pipelines may be joined into	 sequences  with  `;',
       and  will be executed sequentially.  Commands and pipelines can also be
       joined into sequences with `||' or `&&',	indicating, as in the  C  lan-
       guage,  that  the  second  is to	be executed only if the	first fails or
       succeeds	respectively.

       A simple	command, pipeline or sequence may be  placed  in  parentheses,
       `()',  to  form a simple	command, which may in turn be a	component of a
       pipeline	or sequence.  A	command, pipeline or sequence can be  executed
       without waiting for it to terminate by following	it with	an `&'.

   Builtin and non-builtin command execution
       Builtin	commands are executed within the shell.	 If any	component of a
       pipeline	except the last	is a builtin command, the pipeline is executed
       in a subshell.

       Parenthesized commands are always executed in a subshell.

	   (cd;	pwd); pwd

       thus  prints  the  home directory, leaving you where you	were (printing
       this after the home directory), while

	   cd; pwd

       leaves you in the home  directory.   Parenthesized  commands  are  most
       often used to prevent cd	from affecting the current shell.

       When  a command to be executed is found not to be a builtin command the
       shell attempts to execute the command via execve(2).  Each word in  the
       variable	 path  names  a	directory in which the shell will look for the
       command.	 If the	shell is not given a -f	option,	the shell  hashes  the
       names  in  these	directories into an internal table so that it will try
       an execve(2) in only a directory	where there is a possibility that  the
       command	resides	 there.	  This	greatly	speeds command location	when a
       large number of directories are present in the search path. This	 hash-
       ing mechanism is	not used:

       1.  If hashing is turned	explicitly off via unhash.

       2.  If the shell	was given a -f argument.

       3.  For	each  directory	 component of path which does not begin	with a
	   `/'.

       4.  If the command contains a `/'.

       In the above four cases the shell concatenates each  component  of  the
       path  vector  with the given command name to form a path	name of	a file
       which it	then attempts to execute it. If	execution is  successful,  the
       search stops.

       If  the	file  has  execute permissions but is not an executable	to the
       system (i.e., it	is neither an executable  binary  nor  a  script  that
       specifies  its interpreter), then it is assumed to be a file containing
       shell commands and a new	shell is spawned to read it.  The  shell  spe-
       cial  alias  may	 be set	to specify an interpreter other	than the shell
       itself.

       On systems which	do not understand the `#!' script interpreter  conven-
       tion  the  shell	 may  be compiled to emulate it; see the version shell
       variable.  If so, the shell checks the first line of the	file to	see if
       it  is of the form `#!interpreter arg ...'.  If it is, the shell	starts
       interpreter with	the given args and feeds the file to  it  on  standard
       input.

   Input/output
       The  standard  input and	standard output	of a command may be redirected
       with the	following syntax:

       < name  Open file name (which is	first variable,	command	 and  filename
	       expanded) as the	standard input.
       << word Read  the  shell	input up to a line which is identical to word.
	       word is not subjected to	variable, filename or command  substi-
	       tution, and each	input line is compared to word before any sub-
	       stitutions are done on this input line.	Unless a quoting  `\',
	       `"',  `'	 or ``'	appears	in word	variable and command substitu-
	       tion is performed on the	intervening  lines,  allowing  `\'  to
	       quote  `$',  `\'	 and ``'.  Commands which are substituted have
	       all blanks, tabs, and newlines preserved, except	for the	 final
	       newline	which  is dropped.  The	resultant text is placed in an
	       anonymous temporary file	which is given to the command as stan-
	       dard input.
       > name
       _! name
       __ name
       __! name
	       The file	name is	used as	standard output.  If the file does not
	       exist then it is	created; if the	file exists, it	is  truncated,
	       its previous contents being lost.

	       If  the shell variable noclobber	is set,	then the file must not
	       exist or	be a character	special	 file  (e.g.,  a  terminal  or
	       `/dev/null')  or	an error results.  This	helps prevent acciden-
	       tal destruction of files.  In this case the `!'	forms  can  be
	       used to suppress	this check.

	       The  forms  involving  `&' route	the diagnostic output into the
	       specified file  as  well	 as  the  standard  output.   name  is
	       expanded	in the same way	as `<' input filenames are.
       >> name
       ___ name
       __! name
       ___! name
	       Like  `>', but appends output to	the end	of name.  If the shell
	       variable	noclobber is set, then it is an	error for the file not
	       to exist, unless	one of the `!' forms is	given.

       A  command  receives  the environment in	which the shell	was invoked as
       modified	by the input-output parameters and the presence	of the command
       in  a pipeline.	Thus, unlike some previous shells, commands run	from a
       file of shell commands have no access to	the text of  the  commands  by
       default;	 rather	they receive the original standard input of the	shell.
       The `<<'	mechanism should be used to present inline data.  This permits
       shell command scripts to	function as components of pipelines and	allows
       the shell to block read its input.   Note  that	the  default  standard
       input  for  a command run detached is not the empty file	/dev/null, but
       the original standard input of the shell.  If this is a terminal	and if
       the  process  attempts to read from the terminal, then the process will
       block and the user will be notified (see	Jobs).

       Diagnostic output may be	directed through a pipe	with the standard out-
       put.  Simply use	the form `|&' rather than just `|'.

       The  shell  cannot  presently  redirect	diagnostic output without also
       redirecting standard output, but	`(command  >  output-file)  >&	error-
       file'  is often an acceptable workaround.  Either output-file or	error-
       file may	be `/dev/tty' to send output to	the terminal.

   Features
       Having described	how the	shell accepts,	parses	and  executes  command
       lines, we now turn to a variety of its useful features.

   Control flow
       The  shell  contains a number of	commands which 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, due to the	imple-
       mentation, restrict the placement of some of the	commands.

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

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

   Expressions
       The if, while and exit builtin commands use expressions with  a	common
       syntax.	 The expressions can include any of the	operators described in
       the next	three sections.	 Note that the @ builtin  command  (q.v.)  has
       its own separate	syntax.

   Logical, arithmetical and comparison	operators
       These operators are similar to those of C and have the same precedence.
       They include

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

       Here the	precedence increases to	the right, `=='	`!='  `=~'  and	 `!~',
       `<='  `>='  `<'	and  `>',  `<<'	and `>>', `+' and `-', `*' `/' and `%'
       being, in groups, at the	same level.  The `==' `!=' `=~'	and `!~' oper-
       ators  compare  their  arguments	as strings; all	others operate on num-
       bers.  The operators `=~' and `!~' are like `!='	and `=='  except  that
       the  right  hand	 side  is  a  glob-pattern (see	Filename substitution)
       against which the left hand operand is matched.	This reduces the  need
       for use of the switch builtin command in	shell scripts when all that is
       really needed is	pattern	matching.

       Null or missing arguments are  considered  `0'.	 The  results  of  all
       expressions are strings,	which represent	decimal	numbers.  It is	impor-
       tant to note that no two	components of an expression can	appear in  the
       same  word; except when adjacent	to components of expressions which are
       syntactically significant to the	parser (`&' `|'	`<' `>'	`(' `)')  they
       should be surrounded by spaces.

   Command exit	status
       Commands	 can be	executed in expressions	and their exit status returned
       by enclosing them in braces (`{}').  Remember that the braces should be
       separated  from the words of the	command	by spaces.  Command executions
       succeed,	returning true,	i.e., `1', if the command exits	with status 0,
       otherwise they fail, returning false, i.e., `0'.	 If more detailed sta-
       tus information is required then	the command should be executed outside
       of an expression	and the	status shell variable examined.

   File	inquiry	operators
       Some  of	 these operators perform true/false tests on files and related
       objects.	 They are of the form -op file,	where op is one	of

	   r   Read access
	   w   Write access
	   x   Execute access
	   X   Executable in the path or shell builtin,	e.g., `-X ls' and  `-X
	       ls-F' are generally true, but `-X /bin/ls' is not (+)
	   e   Existence
	   o   Ownership
	   z   Zero size
	   s   Non-zero	size (+)
	   f   Plain file
	   d   Directory
	   l   Symbolic	link (+) *
	   b   Block special file (+)
	   c   Character special file (+)
	   p   Named pipe (fifo) (+) *
	   S   Socket special file (+) *
	   u   Set-user-ID bit is set (+)
	   g   Set-group-ID bit	is set (+)
	   k   Sticky bit is set (+)
	   t   file  (which  must be a digit) is an open file descriptor for a
	       terminal	device (+)
	   R   Has been	migrated (convex only) (+)
	   L   Applies subsequent operators in a multiple-operator test	 to  a
	       symbolic	 link rather than to the file to which the link	points
	       (+) *

       file is command and filename expanded and then tested to	see if it  has
       the specified relationship to the real user.  If	file does not exist or
       is inaccessible or, for the operators indicated by `*', if  the	speci-
       fied file type does not exist on	the current system, then all enquiries
       return false, i.e., `0'.

       These operators may be combined for conciseness:	`-xy file' is  equiva-
       lent  to	`-x file && -y file'.  (+) For example,	`-fx' is true (returns
       `1') for	plain executable files,	but not	for directories.

       L may be	used in	a multiple-operator test to apply subsequent operators
       to  a  symbolic	link rather than to the	file to	which the link points.
       For example, `-lLo' is true for links owned by the invoking user.   Lr,
       Lw  and	Lx are always true for links and false for non-links.  L has a
       different meaning when it is the	last operator in  a  multiple-operator
       test; see below.

       It  is  possible	 but  not useful, and sometimes	misleading, to combine
       operators which expect file to be a file	with operators which  do  not,
       (e.g., X	and t).	 Following L with a non-file operator can lead to par-
       ticularly strange results.

       Other operators return other information, i.e., not just	 `0'  or  `1'.
       (+) They	have the same format as	before;	op may be one of

	   A	   Last	 file  access time, as the number of seconds since the
		   epoch
	   A:	   Like	A, but in timestamp format, e.g., `Fri May 14 16:36:10
		   1993'
	   M	   Last	file modification time
	   M:	   Like	M, but in timestamp format
	   C	   Last	inode modification time
	   C:	   Like	C, but in timestamp format
	   D	   Device number
	   I	   Inode number
	   F	   Composite file identifier, in the form device:inode
	   L	   The name of the file	pointed	to by a	symbolic link
	   N	   Number of (hard) links
	   P	   Permissions,	in octal, without leading zero
	   P:	   Like	P, with	leading	zero
	   Pmode   Equivalent  to  `-P file & mode', e.g., `-P22 file' returns
		   `22'	if file	is writable by group and  other,  `20'	if  by
		   group only, and `0' if by neither
	   Pmode:  Like	Pmode:,	with leading zero
	   U	   Numeric userid
	   U:	   Username, or	the numeric userid if the username is unknown
	   G	   Numeric groupid
	   G:	   Groupname,  or  the	numeric	 groupid  if  the groupname is
		   unknown
	   Z	   Size, in bytes

       Only one	of these operators may appear in a multiple-operator test, and
       it must be the last.  Note that L has a different meaning at the	end of
       and elsewhere in	a multiple-operator test.   Because  `0'  is  a	 valid
       return  value  for many of these	operators, they	do not return `0' when
       they fail: most return `-1', and	F returns `:'.

       If the shell is compiled	with POSIX  defined  (see  the	version	 shell
       variable), the result of	a file inquiry is based	on the permission bits
       of the file and not on the result of the	access(2)  system  call.   For
       example,	if one tests a file with -w whose permissions would ordinarily
       allow writing but which is on a file system mounted read-only, the test
       will succeed in a POSIX shell but fail in a non-POSIX shell.

       File  inquiry operators can also	be evaluated with the filetest builtin
       command (q.v.) (+).

   Jobs
       The shell associates a job with each pipeline.  It  keeps  a  table  of
       current jobs, printed by	the jobs command, and assigns them small inte-
       ger numbers.  When a job	is started asynchronously with `&', the	 shell
       prints a	line which looks like

	   [1] 1234

       indicating that the job which was started asynchronously	was job	number
       1 and had one (top-level) process, whose	process	id was 1234.

       If you are running a job	and wish to do something else you may hit  the
       suspend	key  (usually  `^Z'), which sends a STOP signal	to the current
       job.  The shell will then normally indicate that	the job	has been `Sus-
       pended'	and  print  another prompt.  If	the listjobs shell variable is
       set, all	jobs will be listed like the jobs builtin command;  if	it  is
       set  to `long' the listing will be in long format, like `jobs -l'.  You
       can then	manipulate the state of	the suspended job.  You	can put	it  in
       the  ``background''  with the bg	command	or run some other commands and
       eventually bring	the job	back into the ``foreground''  with  fg.	  (See
       also  the  run-fg-editor	 editor	command.)  A `^Z' takes	effect immedi-
       ately and is like an interrupt in that pending output and unread	 input
       are  discarded  when  it	is typed.  The wait builtin command causes the
       shell to	wait for all background	jobs to	complete.

       The `^]'	key sends a delayed suspend signal, which does not generate  a
       STOP signal until a program attempts to read(2) it, to the current job.
       This can	usefully be typed ahead	when you have prepared	some  commands
       for  a job which	you wish to stop after it has read them.  The `^Y' key
       performs	this function in csh(1); in tcsh, `^Y' is an editing  command.
       (+)

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

       There  are  several  ways to refer to jobs in the shell.	 The character
       `%' introduces a	job name.  If you wish to refer	to job number  1,  you
       can  name  it  as `%1'.	Just naming a job brings it to the foreground;
       thus `%1' is a synonym for `fg %1', bringing job	1 back into the	 fore-
       ground.	Similarly, saying `%1 &' resumes job 1 in the background, just
       like `bg	%1'.  A	job can	also be	named by an unambiguous	prefix of  the
       string  typed  in to start it: `%ex' would normally restart a suspended
       ex(1) job, if there were	only one suspended job whose name  began  with
       the  string  `ex'.   It is also possible	to say `%?string' to specify a
       job whose text contains string, if there	is only	one such job.

       The shell maintains a notion of the current and previous	jobs.  In out-
       put  pertaining	to  jobs, the current job is marked with a `+' and the
       previous	job with a `-'.	 The abbreviations `%+', `%', and (by  analogy
       with the	syntax of the history mechanism) `%%' all refer	to the current
       job, and	`%-' refers to the previous job.

       The job control mechanism requires that the stty(1) option `new'	be set
       on  some	systems.  It is	an artifact from a `new' implementation	of the
       tty driver which	allows generation of  interrupt	 characters  from  the
       keyboard	 to tell jobs to stop.	See stty(1) and	the setty builtin com-
       mand for	details	on setting options in the new tty driver.

   Status reporting
       The shell learns	immediately whenever a process changes state.  It nor-
       mally  informs  you  whenever  a	job becomes blocked so that no further
       progress	is possible, but only right before it prints a	prompt.	  This
       is  done	so that	it does	not otherwise disturb your work.  If, however,
       you set the shell variable notify, the shell will  notify  you  immedi-
       ately  of  changes of status in background jobs.	 There is also a shell
       command notify which marks a single process so that its status  changes
       will  be	 immediately  reported.	  By  default notify marks the current
       process;	simply say `notify' after starting a background	 job  to  mark
       it.

       When  you  try  to  leave the shell while jobs are stopped, you will be
       warned that `You	have stopped jobs.' You	may use	the  jobs  command  to
       see  what  they	are.  If you do	this or	immediately try	to exit	again,
       the shell will not warn you a second time, and the suspended jobs  will
       be terminated.

   Automatic, periodic and timed events	(+)
       There are various ways to run commands and take other actions automati-
       cally at	various	times in the ``life cycle'' of the  shell.   They  are
       summarized  here, and described in detail under the appropriate Builtin
       commands, Special shell variables and Special aliases.

       The sched builtin command puts commands in a scheduled-event  list,  to
       be executed by the shell	at a given time.

       The  beepcmd,  cwdcmd,  periodic,  precmd,  postcmd, and	jobcmd Special
       aliases can be set, respectively, to execute commands  when  the	 shell
       wants  to ring the bell,	when the working directory changes, every tpe-
       riod minutes, before each prompt, before	each  command  gets  executed,
       after  each  command  gets  executed,  and  when	a job is started or is
       brought into the	foreground.

       The autologout shell variable can be set	to log out or lock  the	 shell
       after a given number of minutes of inactivity.

       The  mail shell variable	can be set to check for	new mail periodically.

       The printexitvalue shell	variable can be	set to print the  exit	status
       of commands which exit with a status other than zero.

       The  rmstar  shell  variable can	be set to ask the user,	when `rm *' is
       typed, if that is really	what was meant.

       The time	shell variable can be set to execute the time builtin  command
       after the completion of any process that	takes more than	a given	number
       of CPU seconds.

       The watch and who shell variables can be	set to	report	when  selected
       users log in or out, and	the log	builtin	command	reports	on those users
       at any time.

   Native Language System support (+)
       The shell is eight bit clean (if	so compiled;  see  the	version	 shell
       variable)  and  thus  supports  character sets needing this capability.
       NLS support differs depending on	whether	or not the shell was  compiled
       to  use	the  system's NLS (again, see version).	 In either case, 7-bit
       ASCII is	the default character code (e.g., the classification of	 which
       characters  are	printable)  and	 sorting,  and	changing  the  LANG or
       LC_CTYPE	environment variables causes a check for possible  changes  in
       these respects.

       When  using  the	 system's  NLS,	the setlocale(3) function is called to
       determine appropriate character code/classification and sorting	(e.g.,
       a  'en_CA.UTF-8'	 would yield "UTF-8" as	a character code).  This func-
       tion typically examines the LANG	and  LC_CTYPE  environment  variables;
       refer  to the system documentation for further details.	When not using
       the system's NLS, the shell simulates  it  by  assuming	that  the  ISO
       8859-1  character  set is used whenever either of the LANG and LC_CTYPE
       variables are set, regardless of	their values.  Sorting is not affected
       for the simulated NLS.

       In addition, with both real and simulated NLS, all printable characters
       in the range \200-\377, i.e., those  that  have	M-char	bindings,  are
       automatically  rebound to self-insert-command.  The corresponding bind-
       ing for the escape-char sequence, if any, is left alone.	 These charac-
       ters are	not rebound if the NOREBIND environment	variable is set.  This
       may be useful for the simulated NLS  or	a  primitive  real  NLS	 which
       assumes	full  ISO 8859-1.  Otherwise, all M-char bindings in the range
       \240-\377 are effectively undone.  Explicitly  rebinding	 the  relevant
       keys with bindkey is of course still possible.

       Unknown	characters (i.e., those	that are neither printable nor control
       characters) are printed in the format \nnn.  If the tty is not in 8 bit
       mode,  other  8	bit characters are printed by converting them to ASCII
       and using standout mode.	 The shell never changes the 7/8 bit  mode  of
       the  tty	 and tracks user-initiated changes of 7/8 bit mode.  NLS users
       (or, for	that matter, those who want to use a meta  key)	 may  need  to
       explicitly  set	the  tty in 8 bit mode through the appropriate stty(1)
       command in, e.g., the ~/.login file.

   OS variant support (+)
       A number	of new builtin commands	are provided to	 support  features  in
       particular  operating  systems.	 All  are  described  in detail	in the
       Builtin commands	section.

       On  systems  that  support  TCF	(aix-ibm370,  aix-ps2),	 getspath  and
       setspath	 get  and set the system execution path, getxvers and setxvers
       get and set the experimental version prefix and migrate	migrates  pro-
       cesses  between	sites.	The jobs builtin prints	the site on which each
       job is executing.

       Under BS2000, bs2cmd executes commands  of  the	underlying  BS2000/OSD
       operating system.

       Under  Domain/OS,  inlib	 adds shared libraries to the current environ-
       ment, rootnode changes the rootnode and ver changes the systype.

       Under Mach, setpath is equivalent to Mach's setpath(1).

       Under Masscomp/RTU and Harris CX/UX, universe sets the universe.

       Under Harris CX/UX, ucb or att runs a command under the specified  uni-
       verse.

       Under Convex/OS,	warp prints or sets the	universe.

       The  VENDOR, OSTYPE and MACHTYPE	environment variables indicate respec-
       tively the vendor, operating system and	machine	 type  (microprocessor
       class  or  machine model) of the	system on which	the shell thinks it is
       running.	 These are particularly	useful when sharing one's home	direc-
       tory between several types of machines; one can,	for example,

	   set path = (~/bin.$MACHTYPE /usr/ucb	/bin /usr/bin .)

       in  one's ~/.login and put executables compiled for each	machine	in the
       appropriate directory.

       The version shell variable indicates what options were chosen when  the
       shell was compiled.

       Note  also  the	newgrp builtin,	the afsuser and	echo_style shell vari-
       ables and the system-dependent locations	of  the	 shell's  input	 files
       (see FILES).

   Signal handling
       Login  shells  ignore  interrupts when reading the file ~/.logout.  The
       shell ignores quit signals unless started with -q.  Login shells	 catch
       the terminate signal, but non-login shells inherit the terminate	behav-
       ior from	their parents.	Other signals have the values which the	 shell
       inherited from its parent.

       In  shell scripts, the shell's handling of interrupt and	terminate sig-
       nals can	be controlled with onintr, and its handling of hangups can  be
       controlled with hup and nohup.

       The  shell  exits on a hangup (see also the logout shell	variable).  By
       default,	the shell's children do	too, but the shell does	not send  them
       a hangup	when it	exits.	hup arranges for the shell to send a hangup to
       a child when it exits, and nohup	sets a child to	ignore hangups.

   Terminal management (+)
       The shell uses  three  different	 sets  of  terminal  (``tty'')	modes:
       `edit',	used  when editing, `quote', used when quoting literal charac-
       ters, and `execute', used when executing	 commands.   The  shell	 holds
       some settings in	each mode constant, so commands	which leave the	tty in
       a confused state	do not interfere  with	the  shell.   The  shell  also
       matches	changes	 in the	speed and padding of the tty.  The list	of tty
       modes that are kept constant can	be  examined  and  modified  with  the
       setty  builtin.	Note that although the editor uses CBREAK mode (or its
       equivalent), it takes typed-ahead characters anyway.

       The echotc, settc and telltc commands can be  used  to  manipulate  and
       debug terminal capabilities from	the command line.

       On systems that support SIGWINCH	or SIGWINDOW, the shell	adapts to win-
       dow resizing automatically and adjusts the environment variables	 LINES
       and  COLUMNS  if	set.  If the environment variable TERMCAP contains li#
       and co# fields, the shell adjusts them to reflect the new window	 size.

REFERENCE
       The  next sections of this manual describe all of the available Builtin
       commands, Special aliases and Special shell variables.

   Builtin commands
       %job    A synonym for the fg builtin command.

       %job &  A synonym for the bg builtin command.

       :       Does nothing, successfully.

       @
       @ name =	expr
       @ name[index] = expr
       @ name++|--
       @ name[index]++|--
	       The first form prints the values	of all shell variables.

	       The second form assigns the value of expr to name.   The	 third
	       form  assigns  the  value  of expr to the index'th component of
	       name; both name and its index'th	component must already	exist.

	       expr  may  contain  the	operators `*', `+', etc., as in	C.  If
	       expr contains `<', `>', `&' or `' then at least	that  part  of
	       expr  must be placed within `()'.  Note that the	syntax of expr
	       has nothing to do with that described under Expressions.

	       The fourth and fifth forms increment (`++') or decrement	(`--')
	       name or its index'th component.

	       The space between `@' and name is required.  The	spaces between
	       name and	`=' and	between	`=' and	expr are optional.  Components
	       of expr must be separated by spaces.

       alias [name [wordlist]]
	       Without	arguments,  prints all aliases.	 With name, prints the
	       alias for name.	With name and wordlist,	 assigns  wordlist  as
	       the  alias  of  name.  wordlist is command and filename substi-
	       tuted.  name may	not be `alias' or  `unalias'.	See  also  the
	       unalias builtin command.

       alloc   Shows  the  amount of dynamic memory acquired, broken down into
	       used and	free memory.  With an argument	shows  the  number  of
	       free  and  used	blocks	in each	size category.	The categories
	       start at	size 8 and double at each step.	 This command's	output
	       may  vary  across  system types,	because	systems	other than the
	       VAX may use a different memory allocator.

       bg [%job	...]
	       Puts the	specified jobs (or,  without  arguments,  the  current
	       job)  into  the	background,  continuing	each if	it is stopped.
	       job may be a number, a string, `', `%', `+' or `-' as described
	       under Jobs.

       bindkey [-l|-d|-e|-v|-u]	(+)
       bindkey [-a] [-b] [-k] [-r] [--]	key (+)
       bindkey [-a] [-b] [-k] [-c|-s] [--] key command (+)
	       Without	options,  the  first form lists	all bound keys and the
	       editor command to which each is bound, the  second  form	 lists
	       the  editor  command  to	 which key is bound and	the third form
	       binds the editor	command	command	to key.	 Options include:

	       -l  Lists all editor commands and a short description of	 each.
	       -d  Binds  all  keys  to	 the standard bindings for the default
		   editor.
	       -e  Binds all keys to the standard GNU Emacs-like bindings.
	       -v  Binds all keys to the standard vi(1)-like bindings.
	       -a  Lists or changes key-bindings in the	alternative  key  map.
		   This	is the key map used in vi command mode.
	       -b  key	is interpreted as a control character written ^charac-
		   ter (e.g., `^A') or C-character (e.g., `C-A'), a meta char-
		   acter  written  M-character	(e.g.,	`M-A'),	a function key
		   written F-string (e.g., `F-string'),	or an extended	prefix
		   key written X-character (e.g., `X-A').
	       -k  key	is interpreted as a symbolic arrow key name, which may
		   be one of `down', `up', `left' or `right'.
	       -r  Removes key's binding.  Be careful: `bindkey	-r'  does  not
		   bind	key to self-insert-command (q.v.), it unbinds key com-
		   pletely.
	       -c  command is interpreted as a	builtin	 or  external  command
		   instead of an editor	command.
	       -s  command  is taken as	a literal string and treated as	termi-
		   nal input when key is typed.	 Bound	keys  in  command  are
		   themselves reinterpreted, and this continues	for ten	levels
		   of interpretation.
	       --  Forces a break from option processing, so the next word  is
		   taken as key	even if	it begins with '-'.
	       -u (or any invalid option)
		   Prints a usage message.

	       key  may	 be  a	single character or a string.  If a command is
	       bound to	a string, the first character of the string  is	 bound
	       to  sequence-lead-in and	the entire string is bound to the com-
	       mand.

	       Control characters in key can be	literal	(they can be typed  by
	       preceding  them with the	editor command quoted-insert, normally
	       bound to	`^V') or written caret-character  style,  e.g.,	 `^A'.
	       Delete is written `^?'  (caret-question mark).  key and command
	       can contain backslashed escape sequences	(in the	style of  Sys-
	       tem V echo(1)) as follows:

		   \a	   Bell
		   \b	   Backspace
		   \e	   Escape
		   \f	   Form	feed
		   \n	   Newline
		   \r	   Carriage return
		   \t	   Horizontal tab
		   \v	   Vertical tab
		   \nnn	   The ASCII character corresponding to	the octal num-
			   ber nnn

	       `\' nullifies the special meaning of the	 following  character,
	       if it has any, notably `\' and `^'.

       bs2cmd bs2000-command (+)
	       Passes  bs2000-command  to  the	BS2000 command interpreter for
	       execution. Only non-interactive commands	can be	executed,  and
	       it  is  not  possible to	execute	any command that would overlay
	       the image of the	current	process, like /EXECUTE or /CALL-PROCE-
	       DURE. (BS2000 only)

       break   Causes execution	to resume after	the end	of the nearest enclos-
	       ing foreach or while.  The remaining commands  on  the  current
	       line  are  executed.   Multi-level  breaks are thus possible by
	       writing them all	on one line.

       breaksw Causes a	break from a switch, resuming after the	endsw.

       builtins	(+)
	       Prints the names	of all builtin commands.

       bye (+) A synonym for the logout	builtin	command.   Available  only  if
	       the shell was so	compiled; see the version shell	variable.

       case label:
	       A label in a switch statement as	discussed below.

       cd [-p] [-l] [-n|-v] [name]
	       If  a  directory	 name  is  given,  changes the shell's working
	       directory to name.  If not, changes to home.  If	name is	`-' it
	       is  interpreted	as  the	 previous working directory (see Other
	       substitutions).	(+) If name is not a subdirectory of the  cur-
	       rent  directory	(and  does not begin with `/', `./' or `../'),
	       each component of the variable cdpath is	checked	to see	if  it
	       has  a  subdirectory name.  Finally, if all else	fails but name
	       is a shell variable whose value begins with `/',	then  this  is
	       tried to	see if it is a directory.

	       With -p,	prints the final directory stack, just like dirs.  The
	       -l, -n and -v flags have	the same effect	on cd as on dirs,  and
	       they imply -p.  (+)

	       See also	the implicitcd shell variable.

       chdir   A synonym for the cd builtin command.

       complete	[command [word/pattern/list[:select]/[[suffix]/] ...]] (+)
	       Without	arguments, lists all completions.  With	command, lists
	       completions for command.	 With command and word	etc.,  defines
	       completions.

	       command may be a	full command name or a glob-pattern (see File-
	       name substitution).  It can begin with  `-'  to	indicate  that
	       completion should be used only when command is ambiguous.

	       word specifies which word relative to the current word is to be
	       completed, and may be one of the	following:

		   c   Current-word completion.	  pattern  is  a  glob-pattern
		       which  must  match the beginning	of the current word on
		       the command line.  pattern is ignored  when  completing
		       the current word.
		   C   Like  c,	 but includes pattern when completing the cur-
		       rent word.
		   n   Next-word completion.  pattern is a glob-pattern	 which
		       must  match  the	 beginning of the previous word	on the
		       command line.
		   N   Like n, but must	match the beginning of	the  word  two
		       before the current word.
		   p   Position-dependent  completion.	 pattern  is a numeric
		       range, with the same syntax used	to index  shell	 vari-
		       ables, which must include the current word.

	       list,  the list of possible completions,	may be one of the fol-
	       lowing:

		   a	   Aliases
		   b	   Bindings (editor commands)
		   c	   Commands (builtin or	external commands)
		   C	   External commands which  begin  with	 the  supplied
			   path	prefix
		   d	   Directories
		   D	   Directories which begin with	the supplied path pre-
			   fix
		   e	   Environment variables
		   f	   Filenames
		   F	   Filenames which begin with the supplied path	prefix
		   g	   Groupnames
		   j	   Jobs
		   l	   Limits
		   n	   Nothing
		   s	   Shell variables
		   S	   Signals
		   t	   Plain (``text'') files
		   T	   Plain  (``text'')  files  which begin with the sup-
			   plied path prefix
		   v	   Any variables
		   u	   Usernames
		   x	   Like	n, but	prints	select	when  list-choices  is
			   used.
		   X	   Completions
		   $var	   Words from the variable var
		   (...)   Words from the given	list
		   `...`   Words from the output of command

	       select  is an optional glob-pattern.  If	given, words from only
	       list that match select are considered  and  the	fignore	 shell
	       variable	 is  ignored.	The last three types of	completion may
	       not have	a select pattern, and x	uses select as an  explanatory
	       message when the	list-choices editor command is used.

	       suffix  is  a  single  character	to be appended to a successful
	       completion.  If null, no	character is appended.	If omitted (in
	       which  case  the	fourth delimiter can also be omitted), a slash
	       is appended to directories and a	space to other words.

	       Now for some examples.  Some commands take only directories  as
	       arguments, so there's no	point completing plain files.

		   > complete cd 'p/1/d/'

	       completes  only	the  first  word following `cd'	(`p/1')	with a
	       directory.  p-type completion can also be used to  narrow  down
	       command completion:

		   > co[^D]
		   complete compress
		   > complete -co* 'p/0/(compress)/'
		   > co[^D]
		   > compress

	       This completion completes commands (words in position 0,	`p/0')
	       which begin with	`co' (thus matching `co*') to `compress'  (the
	       only  word  in  the list).  The leading `-' indicates that this
	       completion is to	be used	with only ambiguous commands.

		   > complete find 'n/-user/u/'

	       is an example of	n-type completion.  Any	word following	`find'
	       and immediately following `-user' is completed from the list of
	       users.

		   > complete cc 'c/-I/d/'

	       demonstrates c-type completion.	Any word  following  `cc'  and
	       beginning  with	`-I' is	completed as a directory.  `-I'	is not
	       taken as	part of	the directory because we used lowercase	c.

	       Different lists are useful with different commands.

		   > complete alias 'p/1/a/'
		   > complete man 'p/*/c/'
		   > complete set 'p/1/s/'
		   > complete true 'p/1/x:Truth	has no options./'

	       These complete words following `alias' with aliases, `man' with
	       commands,  and `set' with shell variables.  `true' doesn't have
	       any options, so x does nothing when completion is attempted and
	       prints  `Truth  has  no	options.'  when	completion choices are
	       listed.

	       Note that the man example, and several  other  examples	below,
	       could just as well have used 'c/*' or 'n/*' as 'p/*'.

	       Words  can be completed from a variable evaluated at completion
	       time,

		   > complete ftp 'p/1/$hostnames/'
		   > set hostnames = (rtfm.mit.edu tesla.ee.cornell.edu)
		   > ftp [^D]
		   rtfm.mit.edu	tesla.ee.cornell.edu
		   > ftp [^C]
		   >  set  hostnames  =	  (rtfm.mit.edu	  tesla.ee.cornell.edu
		   uunet.uu.net)
		   > ftp [^D]
		   rtfm.mit.edu	tesla.ee.cornell.edu uunet.uu.net

	       or from a command run at	completion time:

		   > complete kill 'p/*/`ps | awk \{print\ \$1\}`/'
		   > kill -9 [^D]
		   23113 23377 23380 23406 23429 23529 23530 PID

	       Note  that the complete command does not	itself quote its argu-
	       ments, so the braces, space and `$' in  `{print	$1}'  must  be
	       quoted explicitly.

	       One command can have multiple completions:

		   > complete dbx 'p/2/(core)/'	'p/*/c/'

	       completes the second argument to	`dbx' with the word `core' and
	       all other arguments with	commands.  Note	 that  the  positional
	       completion   is	specified  before  the	next-word  completion.
	       Because completions are evaluated from left to  right,  if  the
	       next-word completion were specified first it would always match
	       and the positional completion would never be executed.  This is
	       a common	mistake	when defining a	completion.

	       The  select  pattern  is	useful when a command takes files with
	       only particular forms as	arguments.  For	example,

		   > complete cc 'p/*/f:*.[cao]/'

	       completes `cc' arguments	to files ending	in only	`.c', `.a', or
	       `.o'.  select can also exclude files, using negation of a glob-
	       pattern as described under Filename  substitution.   One	 might
	       use

		   > complete rm 'p/*/f:^*.{c,h,cc,C,tex,1,man,l,y}/'

	       to  exclude  precious  source  code  from  `rm' completion.  Of
	       course, one could still type excluded names manually  or	 over-
	       ride  the  completion  mechanism	using the complete-word-raw or
	       list-choices-raw	editor commands	(q.v.).

	       The `C',	`D', `F' and `T' lists are like	`c', `d', `f' and  `t'
	       respectively,  but  they	use the	select argument	in a different
	       way: to restrict	completion to files beginning with a  particu-
	       lar path	prefix.	 For example, the Elm mail program uses	`=' as
	       an abbreviation for one's mail directory.  One might use

		   > complete elm c@=@F:$HOME/Mail/@

	       to complete `elm	-f =' as if it were `elm  -f  ~/Mail/'.	  Note
	       that  we	 used  `@'  instead of `/' to avoid confusion with the
	       select argument,	and we used `$HOME'  instead  of  `~'  because
	       home  directory	substitution  works at only the	beginning of a
	       word.

	       suffix is used to add a nonstandard suffix (not	space  or  `/'
	       for directories)	to completed words.

		   > complete finger 'c/*@/$hostnames/'	'p/1/u/@'

	       completes arguments to `finger' from the	list of	users, appends
	       an `@', and then	completes after	the `@'	from  the  `hostnames'
	       variable.   Note	 again	the order in which the completions are
	       specified.

	       Finally,	here's a complex example for inspiration:

		   > complete find \
		   'n/-name/f/'	'n/-newer/f/' 'n/-{,n}cpio/f/' \
		   'n/-exec/c/'	'n/-ok/c/' 'n/-user/u/'	\
		   'n/-group/g/' 'n/-fstype/(nfs 4.2)/'	\
		   'n/-type/(b c d f l p s)/' \
		   'c/-/(name newer cpio ncpio exec ok user \
		   group fstype	type atime ctime depth inum \
		   ls mtime nogroup nouser perm	print prune \
		   size	xdev)/'	\
		   'p/*/d/'

	       This completes words following `-name',	`-newer',  `-cpio'  or
	       `ncpio'	(note  the pattern which matches both) to files, words
	       following `-exec' or `-ok' to commands, words following	`user'
	       and  `group' to users and groups	respectively and words follow-
	       ing `-fstype' or	`-type'	to members of  the  given  lists.   It
	       also  completes	the  switches  themselves  from	the given list
	       (note the use of	c-type completion) and completes anything  not
	       otherwise completed to a	directory.  Whew.

	       Remember	 that  programmed  completions are ignored if the word
	       being completed is a tilde substitution (beginning with `~') or
	       a  variable  (beginning with `$').  complete is an experimental
	       feature,	and the	syntax may change in future  versions  of  the
	       shell.  See also	the uncomplete builtin command.

       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.  It should  come
	       after all case labels.

       dirs [-l] [-n|-v]
       dirs -S|-L [filename] (+)
       dirs -c (+)
	       The  first  form	 prints	 the  directory	stack.	The top	of the
	       stack is	at the left and	the first directory in	the  stack  is
	       the  current  directory.	 With -l, `~' or `~name' in the	output
	       is expanded explicitly to home or  the  pathname	 of  the  home
	       directory  for  user  name.   (+)  With -n, entries are wrapped
	       before they reach the edge of the screen.  (+) With -v, entries
	       are  printed  one  per line, preceded by	their stack positions.
	       (+) If more than	one of -n or -v	is given, -v takes precedence.
	       -p is accepted but does nothing.

	       With  -S, the second form saves the directory stack to filename
	       as a series of cd and  pushd  commands.	 With  -L,  the	 shell
	       sources	filename,  which  is presumably	a directory stack file
	       saved by	the -S option or the savedirs  mechanism.   In	either
	       case,  dirsfile is used if filename is not given	and ~/.cshdirs
	       is used if dirsfile is unset.

	       Note that login shells  do  the	equivalent  of	`dirs  -L'  on
	       startup	and,  if  savedirs  is	set, `dirs -S' before exiting.
	       Because only ~/.tcshrc is normally sourced  before  ~/.cshdirs,
	       dirsfile	should be set in ~/.tcshrc rather than ~/.login.

	       The last	form clears the	directory stack.

       echo [-n] word ...
	       Writes  each  word to the shell's standard output, separated by
	       spaces and terminated with a  newline.	The  echo_style	 shell
	       variable	 may  be  set to emulate (or not) the flags and	escape
	       sequences of the	BSD and/or System  V  versions	of  echo;  see
	       echo(1).

       echotc [-sv] arg	... (+)
	       Exercises  the  terminal	capabilities (see termcap(5)) in args.
	       For example, 'echotc home' sends	the cursor to the  home	 posi-
	       tion,  'echotc  cm  3  10' sends	it to column 3 and row 10, and
	       'echotc ts 0; echo "This	is a test."; echotc fs'	 prints	 "This
	       is a test."  in the status line.

	       If arg is 'baud', 'cols', 'lines', 'meta' or 'tabs', prints the
	       value of	that capability	("yes" or  "no"	 indicating  that  the
	       terminal	does or	does not have that capability).	 One might use
	       this to make the	output from a shell  script  less  verbose  on
	       slow  terminals,	or limit command output	to the number of lines
	       on the screen:

		   > set history=`echotc lines`
		   > @ history--

	       Termcap strings may contain wildcards which will	not echo  cor-
	       rectly.	 One  should  use  double  quotes when setting a shell
	       variable	to a terminal capability string, as in	the  following
	       example that places the date in the status line:

		   > set tosl="`echotc ts 0`"
		   > set frsl="`echotc fs`"
		   > echo -n "$tosl";date; echo	-n "$frsl"

	       With  -s,  nonexistent  capabilities  return  the  empty	string
	       rather than causing an error.  With -v, messages	are verbose.

       else
       end
       endif
       endsw   See the description of  the  foreach,  if,  switch,  and	 while
	       statements below.

       eval arg	...
	       Treats  the  arguments  as  input to the	shell and executes the
	       resulting command(s) in the context of the current shell.  This
	       is  usually used	to execute commands generated as the result of
	       command or variable substitution, because parsing occurs	before
	       these substitutions.  See tset(1) for a sample use of eval.

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

       exit [expr]
	       The shell exits either with the value of	the specified expr (an
	       expression, as described	under Expressions) or,	without	 expr,
	       with the	value 0.

       fg [%job	...]
	       Brings  the  specified jobs (or,	without	arguments, the current
	       job) into the foreground, continuing each  if  it  is  stopped.
	       job may be a number, a string, `', `%', `+' or `-' as described
	       under Jobs.  See	also the run-fg-editor editor command.

       filetest	-op file ... (+)
	       Applies op (which is a file inquiry operator as described under
	       File inquiry operators) to each file and	returns	the results as
	       a space-separated list.

       foreach name (wordlist)
       ...
       end     Successively sets the variable name to each member of  wordlist
	       and  executes the sequence of commands between this command and
	       the matching end.  (Both	foreach	and end	must appear  alone  on
	       separate	 lines.)   The builtin command continue	may be used to
	       continue	the loop prematurely and the builtin command break  to
	       terminate  it  prematurely.  When this command is read from the
	       terminal, the loop is read once prompting with `foreach?	'  (or
	       prompt2)	 before	 any  statements in the	loop are executed.  If
	       you make	a mistake typing in a loop at the terminal you can rub
	       it out.

       getspath	(+)
	       Prints the system execution path.  (TCF only)

       getxvers	(+)
	       Prints the experimental version prefix.	(TCF only)

       glob wordlist
	       Like  echo,  but	the `-n' parameter is not recognized and words
	       are delimited by	null characters	in  the	 output.   Useful  for
	       programs	 which wish to use the shell to	filename expand	a list
	       of words.

       goto word
	       word is filename	and command-substituted	to yield a  string  of
	       the  form `label'.  The shell rewinds its input as much as pos-
	       sible, searches for a line of the form `label:',	possibly  pre-
	       ceded  by  blanks  or  tabs, and	continues execution after that
	       line.

       hashstat
	       Prints a	statistics line	indicating how effective the  internal
	       hash table has been at locating commands	(and avoiding exec's).
	       An exec is attempted for	each component of the path  where  the
	       hash  function  indicates a possible hit, and in	each component
	       which does not begin with a `/'.

	       On machines without vfork(2), prints only the number  and  size
	       of hash buckets.

       history [-hTr] [n]
       history -S|-L|-M	[filename] (+)
       history -c (+)
	       The  first  form	 prints	the history event list.	 If n is given
	       only the	n most recent events are printed or saved.   With  -h,
	       the  history list is printed without leading numbers.  If -T is
	       specified, timestamps are printed also in comment form.	 (This
	       can be used to produce files suitable for loading with 'history
	       -L' or 'source -h'.)  With -r, the order	of  printing  is  most
	       recent first rather than	oldest first.

	       With  -S,  the  second form saves the history list to filename.
	       If the first word of the	savehist shell variable	is  set	 to  a
	       number,	at most	that many lines	are saved.  If the second word
	       of savehist is set to `merge', the history list is merged  with
	       the  existing history file instead of replacing it (if there is
	       one) and	sorted by time stamp.  (+) Merging is intended for  an
	       environment  like  the  X  Window System	with several shells in
	       simultaneous use.  Currently it succeeds	only when  the	shells
	       quit nicely one after another.

	       With -L,	the shell appends filename, which is presumably	a his-
	       tory list saved by the -S option	or the savehist	mechanism,  to
	       the  history list.  -M is like -L, but the contents of filename
	       are merged into the history list	and sorted by  timestamp.   In
	       either  case,  histfile	is  used  if filename is not given and
	       ~/.history is used if  histfile	is  unset.   `history  -L'  is
	       exactly	like  'source  -h'  except  that it does not require a
	       filename.

	       Note that login shells do the equivalent	 of  `history  -L'  on
	       startup	and,  if savehist is set, `history -S' before exiting.
	       Because only ~/.tcshrc is normally sourced  before  ~/.history,
	       histfile	should be set in ~/.tcshrc rather than ~/.login.

	       If  histlit  is	set, the first and second forms	print and save
	       the literal (unexpanded)	form of	the history list.

	       The last	form clears the	history	list.

       hup [command] (+)
	       With command, runs command such that it will exit on  a	hangup
	       signal  and  arranges  for the shell to send it a hangup	signal
	       when the	shell exits.  Note that	commands  may  set  their  own
	       response	 to  hangups,  overriding  hup.	  Without  an argument
	       (allowed	in only	a shell	script), causes	the shell to exit on a
	       hangup  for  the	remainder of the script.  See also Signal han-
	       dling and the nohup builtin command.

       if (expr) command
	       If expr (an expression, as described under Expressions)	evalu-
	       ates  true, then	command	is executed.  Variable substitution on
	       command happens early, at the same time it does for the rest of
	       the  if	command.   command  must  be  a	simple command,	not an
	       alias, a	pipeline, a command list or  a	parenthesized  command
	       list,  but  it  may  have  arguments.  Input/output redirection
	       occurs even if expr is false and	command	is thus	not  executed;
	       this is a bug.

       if (expr) then
       ...
       else if (expr2) then
       ...
       else
       ...
       endif   If  the	specified  expr	is true	then the commands to the first
	       else are	executed; otherwise if expr2 is	true then the commands
	       to  the	second	else are executed, etc.	 Any number of else-if
	       pairs are possible; only	one endif is needed.  The else part is
	       likewise	 optional.   (The  words else and endif	must appear at
	       the beginning of	input lines; the if must appear	alone  on  its
	       input line or after an else.)

       inlib shared-library ...	(+)
	       Adds  each shared-library to the	current	environment.  There is
	       no way to remove	a shared library.  (Domain/OS only)

       jobs [-l]
	       Lists the active	jobs.  With -l,	lists process IDs in  addition
	       to  the normal information.  On TCF systems, prints the site on
	       which each job is executing.

       kill [-s	signal]	%job|pid ...
       kill -l The first and second forms sends	the specified signal  (or,  if
	       none  is	 given,	 the TERM (terminate) signal) to the specified
	       jobs or processes.  job may be a	number,	a string, `', `%', `+'
	       or  `-'	as  described under Jobs.  Signals are either given by
	       number or by name (as given in /usr/include/signal.h,  stripped
	       of  the	prefix	`SIG').	  There	is no default job; saying just
	       `kill' does not send a signal to	the current job.  If the  sig-
	       nal  being  sent	 is TERM (terminate) or	HUP (hangup), then the
	       job or process is sent a	CONT (continue)	signal as  well.   The
	       third form lists	the signal names.

       limit [-h] [resource [maximum-use]]
	       Limits  the consumption by the current process and each process
	       it creates to not individually exceed maximum-use on the	speci-
	       fied  resource.	 If  no	maximum-use is given, then the current
	       limit is	printed; if no resource	is given, then all limitations
	       are  given.   If	the -h flag is given, the hard limits are used
	       instead of the current limits.  The hard	limits impose a	 ceil-
	       ing  on	the values of the current limits.  Only	the super-user
	       may raise the hard limits, but a	user may lower	or  raise  the
	       current limits within the legal range.

	       Controllable  resources	currently include (if supported	by the
	       OS):

	       cputime
		      the maximum number of cpu-seconds	to  be	used  by  each
		      process

	       filesize
		      the largest single file which can	be created

	       datasize
		      the  maximum growth of the data+stack region via sbrk(2)
		      beyond the end of	the program text

	       stacksize
		      the maximum size	of  the	 automatically-extended	 stack
		      region

	       coredumpsize
		      the size of the largest core dump	that will be created

	       memoryuse
		      the maximum amount of physical memory a process may have
		      allocated	to it at a given time

	       heapsize
		      the maximum amount of memory a process may allocate  per
		      brk() system call

	       descriptors or openfiles
		      the maximum number of open files for this	process

	       concurrency
		      the maximum number of threads for	this process

	       memorylocked
		      the  maximum  size  which	a process may lock into	memory
		      using mlock(2)

	       maxproc
		      the maximum number of simultaneous  processes  for  this
		      user id

	       sbsize the maximum size of socket buffer	usage for this user

	       maximum-use  may	be given as a (floating	point or integer) num-
	       ber followed by a scale factor.	 For  all  limits  other  than
	       cputime the default scale is `k'	or `kilobytes' (1024 bytes); a
	       scale factor of `m' or  `megabytes'  may	 also  be  used.   For
	       cputime the default scaling is `seconds', while `m' for minutes
	       or `h' for hours, or a time of the form `mm:ss' giving  minutes
	       and seconds may be used.

	       For both	resource names and scale factors, unambiguous prefixes
	       of the names suffice.

       log (+) Prints the watch	shell variable and reports on each user	 indi-
	       cated  in  watch	who is logged in, regardless of	when they last
	       logged in.  See also watchlog.

       login   Terminates a login shell, replacing  it	with  an  instance  of
	       /bin/login.  This  is one way to	log off, included for compati-
	       bility with sh(1).

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

       ls-F [-switch ...] [file	...] (+)
	       Lists  files like `ls -F', but much faster.  It identifies each
	       type of special file in the listing with	a special character:

	       /   Directory
	       *   Executable
	       #   Block device
	       %   Character device
	       |   Named pipe (systems with named pipes	only)
	       =   Socket (systems with	sockets	only)
	       @   Symbolic link (systems with symbolic	links only)
	       +   Hidden directory (AIX only)	or  context  dependent	(HP/UX
		   only)
	       :   Network special (HP/UX only)

	       If  the	listlinks  shell  variable  is set, symbolic links are
	       identified in more detail (on only systems that have  them,  of
	       course):

	       @   Symbolic link to a non-directory
	       >   Symbolic link to a directory
	       &   Symbolic link to nowhere

	       listlinks  also	slows  down ls-F and causes partitions holding
	       files pointed to	by symbolic links to be	mounted.

	       If the listflags	shell variable is set to `x', `a' or  `A',  or
	       any combination thereof (e.g., `xA'), they are used as flags to
	       ls-F, making it act like	`ls -xF', `ls -Fa', `ls	-FA' or	a com-
	       bination	 (e.g.,	 `ls -FxA').  On machines where	`ls -C'	is not
	       the default, ls-F acts like `ls -CF', unless listflags contains
	       an  `x',	 in which case it acts like `ls	-xF'.  ls-F passes its
	       arguments to ls(1) if it	is given any switches,	so  `alias  ls
	       ls-F' generally does the	right thing.

	       The  ls-F builtin can list files	using different	colors depend-
	       ing on the filetype or extension.  See the color	tcsh  variable
	       and the LS_COLORS environment variable.

       migrate [-site] pid|%jobid ... (+)
       migrate -site (+)
	       The  first  form	migrates the process or	job to the site	speci-
	       fied or the default site	determined by the  system  path.   The
	       second  form  is	 equivalent to `migrate	-site $$': it migrates
	       the current process to the specified site.  Migrating the shell
	       itself  can  cause  unexpected behavior,	because	the shell does
	       not like	to lose	its tty.  (TCF only)

       newgrp [-] group	(+)
	       Equivalent to `exec newgrp'; see	newgrp(1).  Available only  if
	       the shell was so	compiled; see the version shell	variable.

       nice [+number] [command]
	       Sets the	scheduling priority for	the shell to number, or, with-
	       out number, to 4.  With command,	runs command at	the  appropri-
	       ate priority.  The greater the number, the less cpu the process
	       gets.  The super-user may specify negative  priority  by	 using
	       `nice -number ...'.  Command is always executed in a sub-shell,
	       and the restrictions placed on commands in simple if statements
	       apply.

       nohup [command]
	       With command, runs command such that it will ignore hangup sig-
	       nals.  Note  that  commands  may	 set  their  own  response  to
	       hangups,	 overriding  nohup.   Without  an argument (allowed in
	       only a shell script), causes the	shell to  ignore  hangups  for
	       the  remainder of the script.  See also Signal handling and the
	       hup builtin command.

       notify [%job ...]
	       Causes the shell	to notify the  user  asynchronously  when  the
	       status of any of	the specified jobs (or,	without	%job, the cur-
	       rent job) changes, instead of waiting until the next prompt  as
	       is  usual.   job	may be a number, a string, `', `%', `+'	or `-'
	       as described under Jobs.	 See also the notify shell variable.

       onintr [-|label]
	       Controls	the action of the shell	on interrupts.	Without	 argu-
	       ments,  restores	the default action of the shell	on interrupts,
	       which is	to terminate shell scripts or to return	to the	termi-
	       nal command input level.	 With `-', causes all interrupts to be
	       ignored.	 With label, causes  the  shell	 to  execute  a	 `goto
	       label'  when an interrupt is received or	a child	process	termi-
	       nates because it	was interrupted.

	       onintr is ignored if the	shell is running detached and in  sys-
	       tem  startup  files  (see FILES), where interrupts are disabled
	       anyway.

       popd [-p] [-l] [-n|-v] [+n]
	       Without arguments, pops the directory stack and returns to  the
	       new top directory.  With	a number `+n', discards	the n'th entry
	       in the stack.

	       Finally,	all forms of popd print	 the  final  directory	stack,
	       just  like  dirs.  The pushdsilent shell	variable can be	set to
	       prevent this and	the -p flag can	be given to override  pushdsi-
	       lent.   The -l, -n and -v flags have the	same effect on popd as
	       on dirs.	 (+)

       printenv	[name] (+)
	       Prints the names	and values of all  environment	variables  or,
	       with name, the value of the environment variable	name.

       pushd [-p] [-l] [-n|-v] [name|+n]
	       Without arguments, exchanges the	top two	elements of the	direc-
	       tory stack.  If pushdtohome is  set,  pushd  without  arguments
	       does  `pushd  ~',  like	cd.  (+) With name, pushes the current
	       working directory onto the directory stack and changes to name.
	       If name is `-' it is interpreted	as the previous	working	direc-
	       tory (see Filename substitution).  (+) If dunique is set, pushd
	       removes	any instances of name from the stack before pushing it
	       onto the	stack.	(+) With a number `+n',	rotates	the  nth  ele-
	       ment  of	 the  directory	stack around to	be the top element and
	       changes to  it.	 If  dextract  is  set,	 however,  `pushd  +n'
	       extracts	the nth	directory, pushes it onto the top of the stack
	       and changes to it.  (+)

	       Finally,	all forms of pushd print the  final  directory	stack,
	       just  like  dirs.  The pushdsilent shell	variable can be	set to
	       prevent this and	the -p flag can	be given to override  pushdsi-
	       lent.  The -l, -n and -v	flags have the same effect on pushd as
	       on dirs.	 (+)

       rehash  Causes the internal hash	table of the contents of the  directo-
	       ries  in	the path variable to be	recomputed.  This is needed if
	       new commands are	added to directories in	 path  while  you  are
	       logged  in.   This should be necessary only if you add commands
	       to one of your own directories,	or  if	a  systems  programmer
	       changes	the  contents  of one of the system directories.  Also
	       flushes the cache of home directories built by tilde expansion.

       repeat count command
	       The  specified  command,	 which is subject to the same restric-
	       tions as	the command in the one line  if	 statement  above,  is
	       executed	 count	times.	 I/O  redirections occur exactly once,
	       even if count is	0.

       rootnode	//nodename (+)
	       Changes the rootnode to //nodename, so that `/' will be	inter-
	       preted as `//nodename'.	(Domain/OS only)

       sched (+)
       sched [+]hh:mm command (+)
       sched -n	(+)
	       The  first  form	 prints	 the  scheduled-event list.  The sched
	       shell variable may be set to define the	format	in  which  the
	       scheduled-event	list is	printed.  The second form adds command
	       to the scheduled-event list.  For example,

		   > sched 11:00 echo It\'s eleven o\'clock.

	       causes the shell	to echo	`It's eleven o'clock.' at 11 AM.   The
	       time may	be in 12-hour AM/PM format

		   > sched 5pm set prompt='[%h]	It\'s after 5; go home:	>'

	       or may be relative to the current time:

		   > sched +2:15 /usr/lib/uucp/uucico -r1 -sother

	       A  relative  time  specification	may not	use AM/PM format.  The
	       third form removes item n from the event	list:

		   > sched
			1  Wed Apr  4 15:42  /usr/lib/uucp/uucico -r1 -sother
			2  Wed Apr  4 17:00  set prompt=[%h] It's after	5;  go
		   home: >
		   > sched -2
		   > sched
			1  Wed Apr  4 15:42  /usr/lib/uucp/uucico -r1 -sother

	       A  command  in the scheduled-event list is executed just	before
	       the first prompt	is printed after the time when the command  is
	       scheduled.  It is possible to miss the exact time when the com-
	       mand is to be run, but an overdue command will execute  at  the
	       next  prompt.   A  command  which  comes	due while the shell is
	       waiting for user	input is executed immediately.	However,  nor-
	       mal  operation of an already-running command will not be	inter-
	       rupted so that a	scheduled-event	list element may be run.

	       This mechanism is similar to, but not the same  as,  the	 at(1)
	       command	on  some Unix systems.	Its major disadvantage is that
	       it may not run a	command	at exactly the	specified  time.   Its
	       major  advantage	 is  that because sched	runs directly from the
	       shell, it has access to shell variables and  other  structures.
	       This  provides  a mechanism for changing	one's working environ-
	       ment based on the time of day.

       set
       set name	...
       set name=word ...
       set [-r]	[-f|-l]	name=(wordlist)	... (+)
       set name[index]=word ...
       set -r (+)
       set -r name ... (+)
       set -r name=word	... (+)
	       The first form of the command prints the	 value	of  all	 shell
	       variables.   Variables  which  contain  more than a single word
	       print 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  name  to  the  list	 of  words  in
	       wordlist.   In  all  cases  the	value  is command and filename
	       expanded.  If -r	is specified, the value	is set read-only.   If
	       -f  or  -l  are	specified, set only unique words keeping their
	       order.  -f prefers the first occurrence of a word, and  -l  the
	       last.   The  fifth  form	sets the index'th component of name to
	       word; this component must already exist.	 The sixth form	 lists
	       only  the names of all shell variables that are read-only.  The
	       seventh form makes name read-only, whether  or  not  it	has  a
	       value.	The  second  form  sets	 name to the null string.  The
	       eighth form is the same as the third form, but make name	 read-
	       only at the same	time.

	       These  arguments	 can  be repeated to set and/or	make read-only
	       multiple	variables in a single  set  command.   Note,  however,
	       that  variable  expansion  happens for all arguments before any
	       setting occurs.	Note also that `=' can	be  adjacent  to  both
	       name  and word or separated from	both by	whitespace, but	cannot
	       be adjacent to only one or  the	other.	 See  also  the	 unset
	       builtin command.

       setenv [name [value]]
	       Without	arguments, prints the names and	values of all environ-
	       ment variables.	Given name, sets the environment variable name
	       to value	or, without value, to the null string.

       setpath path (+)
	       Equivalent to setpath(1).  (Mach	only)

       setspath	LOCAL|site|cpu ... (+)
	       Sets the	system execution path.	(TCF only)

       settc cap value (+)
	       Tells the shell to believe that the terminal capability cap (as
	       defined in termcap(5)) has the value value.  No sanity checking
	       is  done.   Concept terminal users may have to `settc xn	no' to
	       get proper wrapping at the rightmost column.

       setty [-d|-q|-x]	[-a] [[+|-]mode] (+)
	       Controls	which tty modes	(see Terminal  management)  the	 shell
	       does  not  allow	to change.  -d,	-q or -x tells setty to	act on
	       the `edit', `quote' or `execute'	set of tty modes respectively;
	       without -d, -q or -x, `execute' is used.

	       Without	other  arguments,  setty lists the modes in the	chosen
	       set which are fixed on (`+mode')	or off (`-mode').  The	avail-
	       able  modes,  and thus the display, vary	from system to system.
	       With -a,	lists all tty modes in the chosen set whether  or  not
	       they  are  fixed.   With	+mode, -mode or	mode, fixes mode on or
	       off or removes control from mode	in the chosen set.  For	 exam-
	       ple, `setty +echok echoe' fixes `echok' mode on and allows com-
	       mands to	turn `echoe' mode on or	off, both when	the  shell  is
	       executing commands.

       setxvers	[string] (+)
	       Set the experimental version prefix to string, or removes it if
	       string is omitted.  (TCF	only)

       shift [variable]
	       Without arguments, discards argv[1] and shifts the  members  of
	       argv  to	the left.  It is an error for argv not to be set or to
	       have less than one word as value.  With variable, performs  the
	       same function on	variable.

       source [-h] name	[args ...]
	       The  shell reads	and executes commands from name.  The commands
	       are not placed on the history list.  If	any  args  are	given,
	       they are	placed in argv.	 (+) source commands may be nested; if
	       they are	nested too deeply  the	shell  may  run	 out  of  file
	       descriptors.   An error in a source at any level	terminates all
	       nested source commands.	With -h, commands are  placed  on  the
	       history list instead of being executed, much like `history -L'.

       stop %job|pid ...
	       Stops the specified jobs	or processes which  are	 executing  in
	       the background.	job may	be a number, a string, `', `%',	`+' or
	       `-' as described	under Jobs.  There is no default  job;	saying
	       just `stop' does	not stop the current job.

       suspend Causes  the shell to stop in its	tracks,	much as	if it had been
	       sent a stop signal with ^Z.  This is most often	used  to  stop
	       shells started by su(1).

       switch (string)
       case str1:
	   ...
	   breaksw
       ...
       default:
	   ...
	   breaksw
       endsw   Each  case label	is successively	matched, against the specified
	       string which is first command and filename expanded.  The  file
	       metacharacters  `*',  `?'  and `[...]'  may be used in the case
	       labels, which are variable expanded.  If	 none  of  the	labels
	       match  before  a	 `default'  label is found, then the execution
	       begins after the	 default  label.   Each	 case  label  and  the
	       default label must appear at the	beginning of a line.  The com-
	       mand breaksw causes execution  to  continue  after  the	endsw.
	       Otherwise  control  may	fall  through  case labels and default
	       labels as in C.	If no label matches and	there is  no  default,
	       execution continues after the endsw.

       telltc (+)
	       Lists the values	of all terminal	capabilities (see termcap(5)).

       termname	[terminal type]	(+)
	       Tests if	terminal type (or the current value of TERM if no ter-
	       minal  type  is	given) has an entry in the hosts termcap(5) or
	       terminfo(5) database. Prints the	terminal type  to  stdout  and
	       returns 0 if an entry is	present	otherwise returns 1.

       time [command]
	       Executes	command	(which must be a simple	command, not an	alias,
	       a pipeline, a command list or a parenthesized command list) and
	       prints a	time summary as	described under	the time variable.  If
	       necessary, an extra shell is created to print the time  statis-
	       tic when	the command completes.	Without	command, prints	a time
	       summary for the current shell and its children.

       umask [value]
	       Sets the	file creation mask to value, which is given in	octal.
	       Common  values  for  the	mask are 002, giving all access	to the
	       group and read and execute access to others,  and  022,	giving
	       read  and  execute  access  to  the  group and others.  Without
	       value, prints the current file creation mask.

       unalias pattern
	       Removes all aliases whose names	match  pattern.	  `unalias  *'
	       thus removes all	aliases.  It is	not an error for nothing to be
	       unaliased.

       uncomplete pattern (+)
	       Removes all completions whose names match pattern.  `uncomplete
	       *'  thus	removes	all completions.  It is	not an error for noth-
	       ing to be uncompleted.

       unhash  Disables	use of the internal hash table to  speed  location  of
	       executed	programs.

       universe	universe (+)
	       Sets the	universe to universe.  (Masscomp/RTU only)

       unlimit [-h] [resource]
	       Removes the limitation on resource or, if no resource is	speci-
	       fied, all resource limitations.	 With  -h,  the	 corresponding
	       hard  limits  are  removed.   Only  the super-user may do this.
	       Note that unlimit may not exit successful, since	 most  systems
	       do not allow descriptors	to be unlimited.

       unset pattern
	       Removes	all  variables	whose names match pattern, unless they
	       are read-only.  `unset *' thus  removes	all  variables	unless
	       they are	read-only; this	is a bad idea.	It is not an error for
	       nothing to be unset.

       unsetenv	pattern
	       Removes all environment variables whose	names  match  pattern.
	       `unsetenv  *' thus removes all environment variables; this is a
	       bad idea.  It is	not an error for nothing to be unsetenved.

       ver [systype [command]] (+)
	       Without arguments, prints SYSTYPE.  With	systype, sets  SYSTYPE
	       to  systype.   With systype and command,	executes command under
	       systype.	 systype may  be  `bsd4.3'  or	`sys5.3'.   (Domain/OS
	       only)

       wait    The  shell  waits  for  all  background	jobs.  If the shell is
	       interactive, an interrupt will disrupt the wait and  cause  the
	       shell  to  print	 the  names and	job numbers of all outstanding
	       jobs.

       warp universe (+)
	       Sets the	universe to universe.  (Convex/OS only)

       watchlog	(+)
	       An alternate name for the log builtin command  (q.v.).	Avail-
	       able  only  if the shell	was so compiled; see the version shell
	       variable.

       where command (+)
	       Reports all known  instances  of	 command,  including  aliases,
	       builtins	and executables	in path.

       which command (+)
	       Displays	 the  command that will	be executed by the shell after
	       substitutions, path searching, etc.   The  builtin  command  is
	       just  like  which(1), but it correctly reports tcsh aliases and
	       builtins	and is 10 to 100 times faster.	See  also  the	which-
	       command editor command.

       while (expr)
       ...
       end     Executes	 the  commands	between	the while and the matching end
	       while expr (an  expression,  as	described  under  Expressions)
	       evaluates  non-zero.   while and	end must appear	alone on their
	       input lines.  break and continue	may be used  to	 terminate  or
	       continue	the loop prematurely.  If the input is a terminal, the
	       user is prompted	the first time through the loop	as with	 fore-
	       ach.

   Special aliases (+)
       If  set,	 each of these aliases executes	automatically at the indicated
       time.  They are all initially undefined.

       beepcmd Runs when the shell wants to ring the terminal bell.

       cwdcmd  Runs after every	change of working directory.  For example,  if
	       the  user is working on an X window system using	xterm(1) and a
	       re-parenting window manager that	supports title	bars  such  as
	       twm(1) and does

		   > alias cwdcmd  'echo -n "^[]2;${HOST}:$cwd ^G"'

	       then the	shell will change the title of the running xterm(1) to
	       be the name of the host,	a colon, and the full current  working
	       directory.  A fancier way to do that is

		   >	      alias	     cwdcmd	     'echo	    -n
		   "^[]2;${HOST}:$cwd^G^[]1;${HOST}^G"'

	       This will put the hostname and working directory	on  the	 title
	       bar but only the	hostname in the	icon manager menu.

	       Note  that  putting  a cd, pushd	or popd	in cwdcmd may cause an
	       infinite	loop.  It is the author's opinion that anyone doing so
	       will get	what they deserve.

       jobcmd  Runs  before  each  command  gets executed, or when the command
	       changes state.  This is similar to postcmd,  but	 it  does  not
	       print builtins.

		   > alias jobcmd  'echo -n "^[]2\;\!#^G"'

	       then  executing	vi  foo.c  will	 put the command string	in the
	       xterm title bar.

       helpcommand
	       Invoked by the run-help editor command.	The command  name  for
	       which  help is sought is	passed as sole argument.  For example,
	       if one does

		   > alias helpcommand '\!:1 --help'

	       then the	help display of	the command itself  will  be  invoked,
	       using  the  GNU help calling convention.	 Currently there is no
	       easy way	to account for various calling conventions (e.g.,  the
	       customary Unix `-h'), except by using a table of	many commands.

       periodic
	       Runs every tperiod minutes.  This provides a  convenient	 means
	       for checking on common but infrequent changes such as new mail.
	       For example, if one does

		   > set tperiod = 30
		   > alias periodic checknews

	       then the	checknews(1) program runs every	30 minutes.  If	 peri-
	       odic  is	set but	tperiod	is unset or set	to 0, periodic behaves
	       like precmd.

       precmd  Runs just before	each prompt is printed.	 For example,  if  one
	       does

		   > alias precmd date

	       then  date(1)  runs just	before the shell prompts for each com-
	       mand.  There are	no limits on what precmd can be	set to do, but
	       discretion should be used.

       postcmd Runs before each	command	gets executed.

		   > alias postcmd  'echo -n "^[]2\;\!#^G"'

	       then  executing	vi  foo.c  will	 put the command string	in the
	       xterm title bar.

       shell   Specifies the interpreter for executable	scripts	which  do  not
	       themselves  specify an interpreter.  The	first word should be a
	       full path name to the desired interpreter (e.g.,	`/bin/csh'  or
	       `/usr/local/bin/tcsh').

   Special shell variables
       The  variables  described  in  this section have	special	meaning	to the
       shell.

       The  shell  sets	 addsuffix,  argv,  autologout,	 csubstnonl,  command,
       echo_style,  edit,  gid,	 group,	 home,	loginsh,  oid,	path,  prompt,
       prompt2,	prompt3, shell,	shlvl, tcsh, term, tty,	uid, user and  version
       at  startup;  they do not change	thereafter unless changed by the user.
       The shell updates cwd, dirstack,	owd and	 status	 when  necessary,  and
       sets logout on logout.

       The shell synchronizes group, home, path, shlvl,	term and user with the
       environment variables of	the same names:	whenever the environment vari-
       able  changes  the  shell  changes  the corresponding shell variable to
       match (unless the shell variable	is read-only) and  vice	 versa.	  Note
       that  although  cwd  and	PWD have identical meanings, they are not syn-
       chronized in this manner, and that the  shell  automatically  intercon-
       verts the different formats of path and PATH.

       addsuffix (+)
	       If  set,	filename completion adds `/' to	the end	of directories
	       and a space to the end of normal	files when  they  are  matched
	       exactly.	 Set by	default.

       afsuser (+)
	       If set, autologout's autolock feature uses its value instead of
	       the local username for kerberos authentication.

       ampm (+)
	       If set, all times are shown in 12-hour AM/PM format.

       argv    The arguments to	the shell.  Positional	parameters  are	 taken
	       from  argv,  i.e., `$1' is replaced by `$argv[1]', etc.	Set by
	       default,	but usually empty in interactive shells.

       autocorrect (+)
	       If set, the spell-word editor command is	invoked	 automatically
	       before each completion attempt.

       autoexpand (+)
	       If  set,	the expand-history editor command is invoked automati-
	       cally before each completion attempt.

       autolist	(+)
	       If set, possibilities are listed	after an ambiguous completion.
	       If  set	to  `ambiguous', possibilities are listed only when no
	       new characters are added	by completion.

       autologout (+)
	       The first word is the number of minutes	of  inactivity	before
	       automatic  logout.   The	 optional second word is the number of
	       minutes of inactivity before automatic locking.	When the shell
	       automatically logs out, it prints `auto-logout',	sets the vari-
	       able logout to `automatic' and exits.  When the shell automati-
	       cally locks, the	user is	required to enter his password to con-
	       tinue working.  Five incorrect  attempts	 result	 in  automatic
	       logout.	Set to `60' (automatic logout after 60 minutes,	and no
	       locking)	by default in login and	superuser shells, but  not  if
	       the shell thinks	it is running under a window system (i.e., the
	       DISPLAY environment variable is set), the tty is	 a  pseudo-tty
	       (pty)  or  the shell was	not so compiled	(see the version shell
	       variable).  See also the	afsuser	and logout shell variables.

       backslash_quote (+)
	       If set, backslashes (`\') always	quote `\', `'',	and `"'.  This
	       may  make complex quoting tasks easier, but it can cause	syntax
	       errors in csh(1)	scripts.

       catalog The file	name  of  the  message	catalog.   If  set,  tcsh  use
	       `tcsh.${catalog}'  as  a	 message  catalog  instead  of default
	       `tcsh'.

       cdpath  A list of directories in	which cd should	search for subdirecto-
	       ries if they aren't found in the	current	directory.

       color   If  set,	 it  enables color display for the builtin ls-F	and it
	       passes --color=auto to ls.  Alternatively, it  can  be  set  to
	       only ls-F or only ls to enable color to only one	command.  Set-
	       ting it to nothing is equivalent	to setting it to (ls-F ls).

       colorcat
	       If set, it enables color	escape sequence	for NLS	message	files.
	       And display colorful NLS	messages.

       command (+)
	       If  set,	 the command which was passed to the shell with	the -c
	       flag (q.v.).

       complete	(+)
	       If set to `enhance', completion 1) ignores case and 2)  consid-
	       ers  periods,  hyphens and underscores (`.', `-'	and `_') to be
	       word separators and hyphens and underscores to  be  equivalent.
	       If set to `igncase', the	completion becomes case	insensitive.

       continue	(+)
	       If  set	to  a  list  of	 commands, the shell will continue the
	       listed commands,	instead	of starting a new one.

       continue_args (+)
	       Same as continue, but the shell will execute:

		   echo	`pwd` $argv > ~/.<cmd>_pause; %<cmd>

       correct (+)
	       If set to `cmd',	commands are automatically spelling-corrected.
	       If set to `complete', commands are automatically	completed.  If
	       set to `all', the entire	command	line is	corrected.

       csubstnonl (+)
	       If set, newlines	and carriage returns in	 command  substitution
	       are replaced by spaces.	Set by default.

       cwd     The  full  pathname  of	the  current  directory.  See also the
	       dirstack	and owd	shell variables.

       dextract	(+)
	       If set, `pushd +n' extracts the nth directory from  the	direc-
	       tory stack rather than rotating it to the top.

       dirsfile	(+)
	       The  default location in	which `dirs -S'	and `dirs -L' look for
	       a history file.	If unset, ~/.cshdirs is	 used.	 Because  only
	       ~/.tcshrc  is  normally	sourced	 before	 ~/.cshdirs,  dirsfile
	       should be set in	~/.tcshrc rather than ~/.login.

       dirstack	(+)
	       An array	 of  all  the  directories  on	the  directory	stack.
	       `$dirstack[1]' is the current working directory,	`$dirstack[2]'
	       the first directory on the stack, etc.  Note that  the  current
	       working directory is `$dirstack[1]' but `=0' in directory stack
	       substitutions, etc.  One	can change the	stack  arbitrarily  by
	       setting	dirstack,  but	the first element (the current working
	       directory) is always correct.  See also the cwd and  owd	 shell
	       variables.

       dspmbyte	(+)
	       Has an affect iff 'dspm'	is listed as part of the version shell
	       variable.  If set to `euc', it enables display and editing EUC-
	       kanji(Japanese) code.  If set to	`sjis',	it enables display and
	       editing Shift-JIS(Japanese) code.  If set to `big5', it enables
	       display	and  editing Big5(Chinese) code.  If set to `utf8', it
	       enables display and editing Utf8(Unicode) code.	If set to  the
	       following  format,  it  enables display and editing of original
	       multi-byte code format:

		   > set dspmbyte = 0000....(256 bytes)....0000

	       The table requires just 256 bytes.  Each	character of 256 char-
	       acters  corresponds  (from  left	 to  right) to the ASCII codes
	       0x00, 0x01, ... 0xff.  Each character is	set  to	 number	 0,1,2
	       and 3.  Each number has the following meaning:
		 0 ... not used	for multi-byte characters.
		 1 ... used for	the first byte of a multi-byte character.
		 2 ... used for	the second byte	of a multi-byte	character.
		 3  ...	 used  for  both  the  first byte and second byte of a
	       multi-byte character.

		 Example:
	       If set to `001322', the first  character	 (means	 0x00  of  the
	       ASCII code) and second character	(means 0x01 of ASCII code) are
	       set to `0'.  Then, it is	not used  for  multi-byte  characters.
	       The  3rd	 character (0x02) is set to '1', indicating that it is
	       used for	the first byte of a  multi-byte	 character.   The  4th
	       character(0x03) is set '3'.  It is used for both	the first byte
	       and the second byte of a	multi-byte character.  The 5th and 6th
	       characters (0x04,0x05) are set to '2', indicating that they are
	       used for	the second byte	of a multi-byte	character.

	       The GNU fileutils version of ls cannot display multi-byte file-
	       names  without  the -N (	--literal ) option.   If you are using
	       this version, set the second word of dspmbyte to	"ls".  If not,
	       for example, "ls-F -l" cannot display multi-byte	filenames.

		 Note:
	       This  variable  can only	be used	if KANJI and DSPMBYTE has been
	       defined at compile time.

       dunique (+)
	       If set, pushd removes any instances  of	name  from  the	 stack
	       before pushing it onto the stack.

       echo    If  set,	 each command with its arguments is echoed just	before
	       it is executed.	For non-builtin	commands all expansions	 occur
	       before echoing.	Builtin	commands are echoed before command and
	       filename	substitution, because  these  substitutions  are  then
	       done selectively.  Set by the -x	command	line option.

       echo_style (+)
	       The style of the	echo builtin.  May be set to

	       bsd     Don't echo a newline if the first argument is `-n'.
	       sysv    Recognize backslashed escape sequences in echo strings.
	       both    Recognize both the `-n'	flag  and  backslashed	escape
		       sequences; the default.
	       none    Recognize neither.

	       Set by default to the local system default.  The	BSD and	System
	       V options are described in the echo(1) man pages	on the	appro-
	       priate systems.

       edit (+)
	       If  set,	 the  command-line  editor is used.  Set by default in
	       interactive shells.

       ellipsis	(+)
	       If set, the `%c'/`%.' and `%C' prompt sequences (see the	prompt
	       shell  variable)	 indicate skipped directories with an ellipsis
	       (`...')	instead	of `/<skipped>'.

       fignore (+)
	       Lists file name suffixes	to be ignored by completion.

       filec   In tcsh,	completion is always used and this variable is ignored
	       by  default. If edit is unset, then the traditional csh comple-
	       tion is used.  If set in	csh, filename completion is used.

       gid (+) The user's real group ID.

       group (+)
	       The user's group	name.

       highlight
	       If set, the incremental search match (in	i-search-back  and  i-
	       search-fwd)  and	the region between the mark and	the cursor are
	       highlighted in reverse video.

	       Highlighting requires  more  frequent  terminal	writes,	 which
	       introduces  extra  overhead. If you care	about terminal perfor-
	       mance, you may want to leave this unset.

       histchars
	       A string	value determining the characters used in History  sub-
	       stitution  (q.v.).  The first character of its value is used as
	       the history substitution	character, replacing the default char-
	       acter  `!'.   The  second  character  of	its value replaces the
	       character `^' in	quick substitutions.

       histdup (+)
	       Controls	handling of duplicate entries in the history list.  If
	       set to `all' only unique	history	events are entered in the his-
	       tory list.  If set to `prev' and	the last history event is  the
	       same  as	 the  current command, then the	current	command	is not
	       entered in the history.	If set to `erase' and the  same	 event
	       is  found  in  the history list,	that old event gets erased and
	       the current one gets inserted.  Note that the `prev' and	 `all'
	       options renumber	history	events so there	are no gaps.

       histfile	(+)
	       The  default  location  in  which `history -S' and `history -L'
	       look for	a history file.	 If unset, ~/.history is used.	 hist-
	       file  is	 useful	 when  sharing the same	home directory between
	       different machines, or when saving separate histories  on  dif-
	       ferent  terminals.   Because only ~/.tcshrc is normally sourced
	       before ~/.history, histfile should be set in  ~/.tcshrc	rather
	       than ~/.login.

       histlit (+)
	       If  set,	builtin	and editor commands and	the savehist mechanism
	       use the literal (unexpanded) form of lines in the history list.
	       See also	the toggle-literal-history editor command.

       history The  first word indicates the number of history events to save.
	       The optional second word	(+) indicates the format in which his-
	       tory  is	 printed;  if  not given, `%h\t%T\t%R\n' is used.  The
	       format sequences	are described below  under  prompt;  note  the
	       variable	meaning	of `%R'.  Set to `100' by default.

       home    Initialized to the home directory of the	invoker.  The filename
	       expansion of `~'	refers to this variable.

       ignoreeof
	       If set to the empty string or `0' and the  input	 device	 is  a
	       terminal,  the  end-of-file  command  (usually generated	by the
	       user by typing `^D' on an empty line) causes the	shell to print
	       `Use  "exit" to leave tcsh.' instead of exiting.	 This prevents
	       the shell from accidentally being  killed.   Historically  this
	       setting	exited	after  26  successive  EOF's to	avoid infinite
	       loops.  If set to a number n, the shell ignores n - 1  consecu-
	       tive  end-of-files  and exits on	the nth.  (+) If unset,	`1' is
	       used, i.e., the shell exits on a	single `^D'.

       implicitcd (+)
	       If set, the shell treats	a directory name typed as a command as
	       though  it  were	a request to change to that directory.	If set
	       to verbose, the change of directory is echoed to	 the  standard
	       output.	 This  behavior	 is inhibited in non-interactive shell
	       scripts,	or for	command	 strings  with	more  than  one	 word.
	       Changing	directory takes	precedence over	executing a like-named
	       command,	but it is done after alias substitutions.   Tilde  and
	       variable	expansions work	as expected.

       inputmode (+)
	       If  set	to  `insert' or	`overwrite', puts the editor into that
	       input mode at the beginning of each line.

       killdup (+)
	       Controls	handling of duplicate entries in the  kill  ring.   If
	       set  to `all' only unique strings are entered in	the kill ring.
	       If set to `prev'	and the	last killed string is the same as  the
	       current	killed	string,	then the current string	is not entered
	       in the ring.  If	set to `erase' and the same string is found in
	       the  kill ring, the old string is erased	and the	current	one is
	       inserted.

       killring	(+)
	       Indicates the number of killed strings to keep in memory.   Set
	       to  `30'	 by  default.	If  unset or set to less than `2', the
	       shell will only keep the	most recently killed string.   Strings
	       are  put	 in  the  killring  by the editor commands that	delete
	       (kill) strings of text, e.g.  backward-delete-word,  kill-line,
	       etc, as well as the copy-region-as-kill command.	 The yank edi-
	       tor command will	yank the most recently killed string into  the
	       command-line,  while yank-pop (see Editor commands) can be used
	       to yank earlier killed strings.

       listflags (+)
	       If set to `x', `a' or `A', or any  combination  thereof	(e.g.,
	       `xA'),  they  are used as flags to ls-F,	making it act like `ls
	       -xF', `ls -Fa', `ls -FA'	or a combination  (e.g.,  `ls  -FxA'):
	       `a'  shows all files (even if they start	with a `.'), `A' shows
	       all files but `.' and `..', and `x'  sorts  across  instead  of
	       down.   If  the	second word of listflags is set, it is used as
	       the path	to `ls(1)'.

       listjobs	(+)
	       If set, all jobs	are listed when	a job is suspended.  If	set to
	       `long', the listing is in long format.

       listlinks (+)
	       If  set,	 the  ls-F  builtin  command shows the type of file to
	       which each symbolic link	points.

       listmax (+)
	       The maximum number of items which the list-choices editor  com-
	       mand will list without asking first.

       listmaxrows (+)
	       The maximum number of rows of items which the list-choices edi-
	       tor command will	list without asking first.

       loginsh (+)
	       Set by the shell	if it is a login shell.	 Setting or  unsetting
	       it within a shell has no	effect.	 See also shlvl.

       logout (+)
	       Set  by	the  shell  to `normal'	before a normal	logout,	`auto-
	       matic' before an	automatic logout, and `hangup'	if  the	 shell
	       was  killed by a	hangup signal (see Signal handling).  See also
	       the autologout shell variable.

       mail    The names of the	files or directories  to  check	 for  incoming
	       mail,  separated	 by  whitespace,  and optionally preceded by a
	       numeric word.  Before each prompt, if 10	 minutes  have	passed
	       since  the last check, the shell	checks each file and says `You
	       have new	mail.' (or, if mail contains multiple files, `You have
	       new  mail  in  name.')  if the filesize is greater than zero in
	       size and	has a modification time	greater	than its access	 time.

	       If  you	are  in	 a  login shell, then no mail file is reported
	       unless it has been  modified  after  the	 time  the  shell  has
	       started	up,  to	 prevent  redundant notifications.  Most login
	       programs	will tell you whether or not you have  mail  when  you
	       log in.

	       If  a  file  specified  in  mail	is a directory,	the shell will
	       count each file within that directory as	 a  separate  message,
	       and  will  report  `You	have n mails.' or `You have n mails in
	       name.' as appropriate.  This functionality is provided  primar-
	       ily  for	those systems which store mail in this manner, such as
	       the Andrew Mail System.

	       If the first word of mail is numeric it is taken	as a different
	       mail checking interval, in seconds.

	       Under  very  rare circumstances,	the shell may report `You have
	       mail.' instead of `You have new mail.'

       matchbeep (+)
	       If  set	to  `never',  completion  never	 beeps.	  If  set   to
	       `nomatch',  it  beeps  only  when there is no match.  If	set to
	       `ambiguous', it beeps when there	are multiple matches.  If  set
	       to  `notunique',	 it  beeps  when  there	is one exact and other
	       longer matches.	If unset, `ambiguous' is used.

       nobeep (+)
	       If set, beeping is completely disabled.	See also  visiblebell.

       noclobber
	       If set, restrictions are	placed on output redirection to	insure
	       that files are not accidentally destroyed and that  `>>'	 redi-
	       rections	  refer	  to  existing	files,	as  described  in  the
	       Input/output section.

       noding  If set, disable the printing of	`DING!'	 in  the  prompt  time
	       specifiers at the change	of hour.

       noglob  If  set,	Filename substitution and Directory stack substitution
	       (q.v.) are inhibited.  This is most  useful  in	shell  scripts
	       which  do not deal with filenames, or after a list of filenames
	       has been	obtained and further expansions	are not	desirable.

       nokanji (+)
	       If set and the shell supports  Kanji  (see  the	version	 shell
	       variable), it is	disabled so that the meta key can be used.

       nonomatch
	       If set, a Filename substitution or Directory stack substitution
	       (q.v.)  which  does  not	 match	any  existing  files  is  left
	       untouched  rather  than causing an error.  It is	still an error
	       for the substitution to be  malformed,  e.g.,  `echo  ['	 still
	       gives an	error.

       nostat (+)
	       A  list	of  directories	(or glob-patterns which	match directo-
	       ries; see Filename substitution)	that should not	 be  stat(2)ed
	       during a	completion operation.  This is usually used to exclude
	       directories which take too much time to	stat(2),  for  example
	       /afs.

       notify  If  set,	 the  shell  announces job completions asynchronously.
	       The default is to present job completions just before  printing
	       a prompt.

       oid (+) The user's real organization ID.	 (Domain/OS only)

       owd (+) The old working directory, equivalent to	the `-'	used by	cd and
	       pushd.  See also	the cwd	and dirstack shell variables.

       padhour If set, enable the printing of padding '0' for hours, in	24 and
	       12 hour formats.	 E.G.: 07:45:42	vs. 7:45:42

       path    A list of directories in	which to look for executable commands.
	       A null word specifies the current directory.  If	 there	is  no
	       path  variable then only	full path names	will execute.  path is
	       set by the shell	at startup from	the PATH environment  variable
	       or, if PATH does	not exist, to a	system-dependent default some-
	       thing like `(/usr/local/bin /usr/bsd /bin  /usr/bin  .)'.   The
	       shell  may  put	`.'  first or last in path or omit it entirely
	       depending on how	it was compiled; see the version  shell	 vari-
	       able.   A shell which is	given neither the -c nor the -t	option
	       hashes the contents of the directories in  path	after  reading
	       ~/.tcshrc  and each time	path is	reset.	If one adds a new com-
	       mand to a directory in path while the shell is active, one  may
	       need to do a rehash for the shell to find it.

       printexitvalue (+)
	       If set and an interactive program exits with a non-zero status,
	       the shell prints	`Exit status'.

       prompt  The string which	is printed before reading  each	 command  from
	       the  terminal.  prompt may include any of the following format-
	       ting sequences (+), which are replaced by  the  given  informa-
	       tion:

	       %/  The current working directory.
	       %~  The	current	 working directory, but	with one's home	direc-
		   tory	represented by `~' and other users'  home  directories
		   represented	 by  `~user'  as  per  Filename	 substitution.
		   `~user' substitution	happens	only if	the shell has  already
		   used	`~user'	in a pathname in the current session.
	       %c[[0]n], %.[[0]n]
		   The trailing	component of the current working directory, or
		   n trailing components if a digit n is given.	 If  n	begins
		   with	 `0',  the  number  of	skipped	components precede the
		   trailing component(s) in the	 format	 `/<skipped>trailing'.
		   If  the  ellipsis shell variable is set, skipped components
		   are	represented  by	 an  ellipsis  so  the	whole  becomes
		   `...trailing'.   `~'	substitution is	done as	in `%~'	above,
		   but the `~' component is  ignored  when  counting  trailing
		   components.
	       %C  Like	%c, but	without	`~' substitution.
	       %h, %!, !
		   The current history event number.
	       %M  The full hostname.
	       %m  The hostname	up to the first	`.'.
	       %S (%s)
		   Start (stop)	standout mode.
	       %B (%b)
		   Start (stop)	boldfacing mode.
	       %U (%u)
		   Start (stop)	underline mode.
	       %t, %@
		   The time of day in 12-hour AM/PM format.
	       %T  Like	 `%t',	but  in	24-hour	format (but see	the ampm shell
		   variable).
	       %p  The `precise' time of day in	 12-hour  AM/PM	 format,  with
		   seconds.
	       %P  Like	 `%p',	but  in	24-hour	format (but see	the ampm shell
		   variable).
	       \c  c is	parsed as in bindkey.
	       ^c  c is	parsed as in bindkey.
	       %%  A single `%'.
	       %n  The user name.
	       %j  The number of jobs.
	       %d  The weekday in `Day'	format.
	       %D  The day in `dd' format.
	       %w  The month in	`Mon' format.
	       %W  The month in	`mm' format.
	       %y  The year in `yy' format.
	       %Y  The year in `yyyy' format.
	       %l  The shell's tty.
	       %L  Clears from the end of the prompt to	end of the display  or
		   the end of the line.
	       %$  Expands  the	shell or environment variable name immediately
		   after the `$'.
	       %#  `>' (or the first character of the promptchars shell	 vari-
		   able)  for  normal  users,  `#' (or the second character of
		   promptchars)	for the	superuser.
	       %{string%}
		   Includes string as a	literal	escape sequence.  It should be
		   used	only to	change terminal	attributes and should not move
		   the cursor location.	 This cannot be	the last  sequence  in
		   prompt.
	       %?  The	return	code  of  the command executed just before the
		   prompt.
	       %R  In prompt2, the status of the parser.  In prompt3, the cor-
		   rected string.  In history, the history string.

	       `%B',  `%S', `%U' and `%{string%}' are available	in only	eight-
	       bit-clean shells; see the version shell variable.

	       The bold, standout and underline	sequences are  often  used  to
	       distinguish a superuser shell.  For example,

		   > set prompt	= "%m [%h] %B[%@]%b [%/] you rang? "
		   tut [37] [2:54pm] [/usr/accts/sys] you rang?	_

	       If  `%t',  `%@',	`%T', `%p', or `%P' is used, and noding	is not
	       set, then print `DING!' on the change of	hour (i.e, `:00'  min-
	       utes) instead of	the actual time.

	       Set by default to `%# ' in interactive shells.

       prompt2 (+)
	       The  string with	which to prompt	in while and foreach loops and
	       after lines ending in `\'.  The same format  sequences  may  be
	       used  as	 in  prompt (q.v.); note the variable meaning of `%R'.
	       Set by default to `%R? '	in interactive shells.

       prompt3 (+)
	       The string with	which  to  prompt  when	 confirming  automatic
	       spelling	 correction.  The same format sequences	may be used as
	       in prompt (q.v.); note the variable meaning of  `%R'.   Set  by
	       default to `CORRECT>%R (y|n|e|a)? ' in interactive shells.

       promptchars (+)
	       If  set	(to  a	two-character  string),	 the  `%#'  formatting
	       sequence	in the prompt shell  variable  is  replaced  with  the
	       first  character	 for normal users and the second character for
	       the superuser.

       pushdtohome (+)
	       If set, pushd without arguments does `pushd ~', like cd.

       pushdsilent (+)
	       If set, pushd and popd do not print the directory stack.

       recexact	(+)
	       If set, completion completes on an exact	match even if a	longer
	       match is	possible.

       recognize_only_executables (+)
	       If  set,	 command  listing displays only	files in the path that
	       are executable.	Slow.

       rmstar (+)
	       If set, the user	is prompted before `rm *' is executed.

       rprompt (+)
	       The string to print on the right-hand side of the screen	(after
	       the  command  input)  when the prompt is	being displayed	on the
	       left.  It recognizes the	same formatting	characters as  prompt.
	       It  will	 automatically disappear and reappear as necessary, to
	       ensure that command input isn't obscured, and will appear  only
	       if  the	prompt,	command	input, and itself will fit together on
	       the first line.	If  edit  isn't	 set,  then  rprompt  will  be
	       printed after the prompt	and before the command input.

       savedirs	(+)
	       If  set,	the shell does `dirs -S' before	exiting.  If the first
	       word is set to a	number,	at  most  that	many  directory	 stack
	       entries are saved.

       savehist
	       If  set,	 the  shell  does `history -S' before exiting.	If the
	       first word is set to a number, at  most	that  many  lines  are
	       saved.  (The number must	be less	than or	equal to history.)  If
	       the second word is set to `merge', the history list  is	merged
	       with  the  existing  history  file  instead of replacing	it (if
	       there is	one) and sorted	by time	 stamp	and  the  most	recent
	       events are retained.  (+)

       sched (+)
	       The  format in which the	sched builtin command prints scheduled
	       events; if not  given,  `%h\t%T\t%R\n'  is  used.   The	format
	       sequences  are  described above under prompt; note the variable
	       meaning of `%R'.

       shell   The file	in which the shell resides.  This is used  in  forking
	       shells  to  interpret  files  which  have execute bits set, but
	       which are not executable	by the system.	(See  the  description
	       of  Builtin and non-builtin command execution.)	Initialized to
	       the (system-dependent) home of the shell.

       shlvl (+)
	       The number of nested shells.  Reset to 1	in login shells.   See
	       also loginsh.

       status  The  status  returned  by  the  last command.  If it terminated
	       abnormally, then	0200 is	added to the status.  Builtin commands
	       which  fail  return exit	status `1', all	other builtin commands
	       return status `0'.

       symlinks	(+)
	       Can be set to several different values to control symbolic link
	       (`symlink') resolution:

	       If  set to `chase', whenever the	current	directory changes to a
	       directory containing a symbolic link, it	 is  expanded  to  the
	       real name of the	directory to which the link points.  This does
	       not work	for the	user's home directory; this is a bug.

	       If set to `ignore', the shell  tries  to	 construct  a  current
	       directory relative to the current directory before the link was
	       crossed.	 This means that cding through	a  symbolic  link  and
	       then  `cd  ..'ing  returns one to the original directory.  This
	       affects only builtin commands and filename completion.

	       If set to `expand', the shell tries to fix  symbolic  links  by
	       actually	 expanding arguments which look	like path names.  This
	       affects any command, not	just  builtins.	  Unfortunately,  this
	       does  not  work	for hard-to-recognize filenames, such as those
	       embedded	in command options.  Expansion	may  be	 prevented  by
	       quoting.	 While this setting is usually the most	convenient, it
	       is sometimes misleading and sometimes confusing when  it	 fails
	       to  recognize  an argument which	should be expanded.  A compro-
	       mise is to use `ignore' and use the editor  command  normalize-
	       path (bound by default to ^X-n) when necessary.

	       Some  examples  are  in	order.	 First,	let's set up some play
	       directories:

		   > cd	/tmp
		   > mkdir from	from/src to
		   > ln	-s from/src to/dst

	       Here's the behavior with	symlinks unset,

		   > cd	/tmp/to/dst; echo $cwd
		   /tmp/to/dst
		   > cd	..; echo $cwd
		   /tmp/from

	       here's the behavior with	symlinks set to	`chase',

		   > cd	/tmp/to/dst; echo $cwd
		   /tmp/from/src
		   > cd	..; echo $cwd
		   /tmp/from

	       here's the behavior with	symlinks set to	`ignore',

		   > cd	/tmp/to/dst; echo $cwd
		   /tmp/to/dst
		   > cd	..; echo $cwd
		   /tmp/to

	       and here's the behavior with symlinks set to `expand'.

		   > cd	/tmp/to/dst; echo $cwd
		   /tmp/to/dst
		   > cd	..; echo $cwd
		   /tmp/to
		   > cd	/tmp/to/dst; echo $cwd
		   /tmp/to/dst
		   > cd	".."; echo $cwd
		   /tmp/from
		   > /bin/echo ..
		   /tmp/to
		   > /bin/echo ".."
		   ..

	       Note that `expand' expansion 1) works just  like	 `ignore'  for
	       builtins	 like  cd,  2) is prevented by quoting,	and 3) happens
	       before filenames	are passed to non-builtin commands.

       tcsh (+)
	       The version number of the shell in the format `R.VV.PP',	 where
	       `R'  is	the major release number, `VV' the current version and
	       `PP' the	patchlevel.

       term    The terminal type.  Usually set in ~/.login as described	 under
	       Startup and shutdown.

       time    If set to a number, then	the time builtin (q.v.)	executes auto-
	       matically after each command which takes	more  than  that  many
	       CPU seconds.  If	there is a second word,	it is used as a	format
	       string for the output of	the time builtin.  (u)	The  following
	       sequences may be	used in	the format string:

	       %U  The time the	process	spent in user mode in cpu seconds.
	       %S  The time the	process	spent in kernel	mode in	cpu seconds.
	       %E  The elapsed (wall clock) time in seconds.
	       %P  The CPU percentage computed as (%U +	%S) / %E.
	       %W  Number of times the process was swapped.
	       %X  The average amount in (shared) text space used in Kbytes.
	       %D  The	average	 amount	in (unshared) data/stack space used in
		   Kbytes.
	       %K  The total space used	(%X + %D) in Kbytes.
	       %M  The maximum memory the process had in use at	 any  time  in
		   Kbytes.
	       %F  The	number of major	page faults (page needed to be brought
		   from	disk).
	       %R  The number of minor page faults.
	       %I  The number of input operations.
	       %O  The number of output	operations.
	       %r  The number of socket	messages received.
	       %s  The number of socket	messages sent.
	       %k  The number of signals received.
	       %w  The number of voluntary context switches (waits).
	       %c  The number of involuntary context switches.

	       Only the	first four sequences are supported on systems  without
	       BSD  resource limit functions.  The default time	format is `%Uu
	       %Ss %E %P %X+%Dk	%I+%Oio	%Fpf+%Ww'  for	systems	 that  support
	       resource	 usage	reporting and `%Uu %Ss %E %P' for systems that
	       do not.

	       Under Sequent's DYNIX/ptx, %X, %D, %K, %r and %s	are not	avail-
	       able, but the following additional sequences are:

	       %Y  The number of system	calls performed.
	       %Z  The number of pages which are zero-filled on	demand.
	       %i  The	number	of  times  a  process's	 resident set size was
		   increased by	the kernel.
	       %d  The number of times	a  process's  resident	set  size  was
		   decreased by	the kernel.
	       %l  The number of read system calls performed.
	       %m  The number of write system calls performed.
	       %p  The number of reads from raw	disk devices.
	       %q  The number of writes	to raw disk devices.

	       and  the	 default  time	format	is  `%Uu  %Ss  %E  %P  %I+%Oio
	       %Fpf+%Ww'.  Note	that the CPU percentage	 can  be  higher  than
	       100% on multi-processors.

       tperiod (+)
	       The period, in minutes, between executions of the periodic spe-
	       cial alias.

       tty (+) The name	of the tty, or empty if	not attached to	one.

       uid (+) The user's real user ID.

       user    The user's login	name.

       verbose If set, causes the words	of each	command	to be  printed,	 after
	       history	substitution  (if  any).   Set	by the -v command line
	       option.

       version (+)
	       The version ID stamp.  It contains the shell's  version	number
	       (see  tcsh), origin, release date, vendor, operating system and
	       machine (see VENDOR, OSTYPE and MACHTYPE) and a comma-separated
	       list  of	options	which were set at compile time.	 Options which
	       are set by default in the distribution are noted.

	       8b    The shell is eight	bit clean; default
	       7b    The shell is not eight bit	clean
	       wide  The shell is multibyte encoding clean (like UTF-8)
	       nls   The system's NLS is used; default for systems with	NLS
	       lf    Login shells execute  /etc/csh.login  before  instead  of
		     after /etc/csh.cshrc and ~/.login before instead of after
		     ~/.tcshrc and ~/.history.
	       dl    `.' is put	last in	path for security; default
	       nd    `.' is omitted from path for security
	       vi    vi-style editing is the default rather than emacs
	       dtr   Login shells drop DTR when	exiting
	       bye   bye is a synonym for logout and log is an alternate  name
		     for watchlog
	       al    autologout	is enabled; default
	       kan   Kanji  is	used  if  appropriate according	to locale set-
		     tings, unless the nokanji shell variable is set
	       sm    The system's malloc(3) is used
	       hb    The `#!<program> <args>' convention is emulated when exe-
		     cuting shell scripts
	       ng    The newgrp	builtin	is available
	       rh    The  shell	 attempts  to  set  the	REMOTEHOST environment
		     variable
	       afs   The shell verifies	your password with the kerberos	server
		     if	 local	authentication fails.  The afsuser shell vari-
		     able or the AFSUSER environment  variable	override  your
		     local username if set.

	       An  administrator may enter additional strings to indicate dif-
	       ferences	in the local version.

       visiblebell (+)
	       If set, a screen	flash is used rather than  the	audible	 bell.
	       See also	nobeep.

       watch (+)
	       A  list of user/terminal	pairs to watch for logins and logouts.
	       If either the user is `any' all terminals are watched  for  the
	       given  user  and	 vice  versa.	Setting	 watch	to `(any any)'
	       watches all users and terminals.	 For example,

		   set watch = (george ttyd1 any console $user any)

	       reports activity	of the user `george' on	ttyd1, any user	on the
	       console,	and oneself (or	a trespasser) on any terminal.

	       Logins and logouts are checked every 10 minutes by default, but
	       the first word of watch can be set to a number to  check	 every
	       so many minutes.	 For example,

		   set watch = (1 any any)

	       reports any login/logout	once every minute.  For	the impatient,
	       the log builtin command triggers	a watch	report	at  any	 time.
	       All  current logins are reported	(as with the log builtin) when
	       watch is	first set.

	       The who shell variable controls the format of watch reports.

       who (+) The format string for watch messages.  The following  sequences
	       are replaced by the given information:

	       %n  The name of the user	who logged in/out.
	       %a  The	observed  action,  i.e.,  `logged on', `logged off' or
		   `replaced olduser on'.
	       %l  The terminal	(tty) on which the user	logged in/out.
	       %M  The full hostname of	the remote host,  or  `local'  if  the
		   login/logout	was from the local host.
	       %m  The	hostname  of the remote	host up	to the first `.'.  The
		   full	name is	printed	if it is an IP address or an X	Window
		   System display.

	       %M  and	%m are available on only systems that store the	remote
	       hostname	in /etc/utmp.  If unset, `%n has %a %l	from  %m.'  is
	       used,  or  `%n  has  %a	%l.'  on systems which don't store the
	       remote hostname.

       wordchars (+)
	       A list of non-alphanumeric characters to	be considered part  of
	       a  word	by  the	 forward-word, backward-word etc., editor com-
	       mands.  If unset, `*?_-.[]~=' is	used.

ENVIRONMENT
       AFSUSER (+)
	       Equivalent to the afsuser shell variable.

       COLUMNS The number of columns in	the terminal.	See  Terminal  manage-
	       ment.

       DISPLAY Used by X Window	System (see X(1)).  If set, the	shell does not
	       set autologout (q.v.).

       EDITOR  The pathname to a default editor.  See also the VISUAL environ-
	       ment variable and the run-fg-editor editor command.

       GROUP (+)
	       Equivalent to the group shell variable.

       HOME    Equivalent to the home shell variable.

       HOST (+)
	       Initialized  to	the  name of the machine on which the shell is
	       running,	as determined by the gethostname(2) system call.

       HOSTTYPE	(+)
	       Initialized to the type of machine on which the shell  is  run-
	       ning, as	determined at compile time.  This variable is obsolete
	       and will	be removed in a	future version.

       HPATH (+)
	       A colon-separated list of directories  in  which	 the  run-help
	       editor command looks for	command	documentation.

       LANG    Gives the preferred character environment.  See Native Language
	       System support.

       LC_CTYPE
	       If set, only ctype character handling is	changed.   See	Native
	       Language	System support.

       LINES   The  number of lines in the terminal.  See Terminal management.

       LS_COLORS
	       The format of this variable is reminiscent  of  the  termcap(5)
	       file  format; a colon-separated list of expressions of the form
	       "xx=string", where "xx" is a two-character variable name.   The
	       variables with their associated defaults	are:

		   no	0      Normal (non-filename) text
		   fi	0      Regular file
		   di	01;34  Directory
		   ln	01;36  Symbolic	link
		   pi	33     Named pipe (FIFO)
		   so	01;35  Socket
		   do	01;35  Door
		   bd	01;33  Block device
		   cd	01;32  Character device
		   ex	01;32  Executable file
		   mi	(none) Missing file (defaults to fi)
		   or	(none) Orphaned	symbolic link (defaults	to ln)
		   lc	^[[    Left code
		   rc	m      Right code
		   ec	(none) End code	(replaces lc+no+rc)

	       You  need to include only the variables you want	to change from
	       the default.

	       File names can also be colorized	based on  filename  extension.
	       This  is	 specified  in the LS_COLORS variable using the	syntax
	       "*ext=string".  For example, using ISO 6429 codes, to color all
	       C-language  source files	blue you would specify "*.c=34".  This
	       would color all files ending in .c in blue (34) color.

	       Control characters can be  written  either  in  C-style-escaped
	       notation,  or  in  stty-like  ^-notation.  The C-style notation
	       adds ^[ for Escape, _ for a normal space	character, and	?  for
	       Delete.	 In  addition,	the ^[ escape character	can be used to
	       override	the default interpretation of ^[, ^, : and =.

	       Each file will be written as <lc> <color-code> <rc>  <filename>
	       <ec>.   If  the	<ec> code is undefined,	the sequence <lc> <no>
	       <rc> will be used instead.  This	is generally  more  convenient
	       to  use,	 but  less general.  The left, right and end codes are
	       provided	so you don't have to type common parts over  and  over
	       again  and  to  support weird terminals;	you will generally not
	       need to change them at all unless your terminal	does  not  use
	       ISO 6429	color sequences	but a different	system.

	       If your terminal	does use ISO 6429 color	codes, you can compose
	       the type	codes (i.e., all except	the lc,	rc, and	ec codes) from
	       numerical  commands  separated  by semicolons.  The most	common
	       commands	are:

		       0   to restore default color
		       1   for brighter	colors
		       4   for underlined text
		       5   for flashing	text
		       30  for black foreground
		       31  for red foreground
		       32  for green foreground
		       33  for yellow (or brown) foreground
		       34  for blue foreground
		       35  for purple foreground
		       36  for cyan foreground
		       37  for white (or gray) foreground
		       40  for black background
		       41  for red background
		       42  for green background
		       43  for yellow (or brown) background
		       44  for blue background
		       45  for purple background
		       46  for cyan background
		       47  for white (or gray) background

	       Not all commands	will work on all systems or display devices.

	       A few terminal programs do not recognize	the default  end  code
	       properly.   If all text gets colorized after you	do a directory
	       listing,	try changing the no and	fi codes from 0	to the numeri-
	       cal codes for your standard fore- and background	colors.

       MACHTYPE	(+)
	       The  machine  type  (microprocessor class or machine model), as
	       determined at compile time.

       NOREBIND	(+)
	       If set, printable characters are	not  rebound  to  self-insert-
	       command.	 See Native Language System support.

       OSTYPE (+)
	       The operating system, as	determined at compile time.

       PATH    A colon-separated list of directories in	which to look for exe-
	       cutables.  Equivalent to	the path shell variable, but in	a dif-
	       ferent format.

       PWD (+) Equivalent  to  the cwd shell variable, but not synchronized to
	       it; updated only	after an actual	directory change.

       REMOTEHOST (+)
	       The host	from which the user has	logged in remotely, if this is
	       the  case  and  the shell is able to determine it.  Set only if
	       the shell was so	compiled; see the version shell	variable.

       SHLVL (+)
	       Equivalent to the shlvl shell variable.

       SYSTYPE (+)
	       The current system type.	 (Domain/OS only)

       TERM    Equivalent to the term shell variable.

       TERMCAP The terminal capability string.	See Terminal management.

       USER    Equivalent to the user shell variable.

       VENDOR (+)
	       The vendor, as determined at compile time.

       VISUAL  The pathname to a default full-screen  editor.	See  also  the
	       EDITOR  environment  variable and the run-fg-editor editor com-
	       mand.

FILES
       /etc/csh.cshrc  Read first by every shell.  ConvexOS, Stellix and Intel
		       use  /etc/cshrc	and  NeXTs  use	/etc/cshrc.std.	 A/UX,
		       AMIX, Cray and IRIX have	no equivalent in  csh(1),  but
		       read  this  file	 in tcsh anyway.  Solaris 2.x does not
		       have it either, but tcsh	reads /etc/.cshrc.  (+)
       /etc/csh.login  Read by login shells after  /etc/csh.cshrc.   ConvexOS,
		       Stellix	 and   Intel   use   /etc/login,   NeXTs   use
		       /etc/login.std, Solaris 2.x uses	/etc/.login and	 A/UX,
		       AMIX, Cray and IRIX use /etc/cshrc.
       ~/.tcshrc (+)   Read by every shell after /etc/csh.cshrc	or its equiva-
		       lent.
       ~/.cshrc	       Read by every shell, if ~/.tcshrc doesn't exist,	 after
		       /etc/csh.cshrc  or  its	equivalent.   This manual uses
		       `~/.tcshrc' to mean `~/.tcshrc or, if ~/.tcshrc is  not
		       found, ~/.cshrc'.
       ~/.history      Read  by	 login	shells	after ~/.tcshrc	if savehist is
		       set, but	see also histfile.
       ~/.login	       Read by login shells  after  ~/.tcshrc  or  ~/.history.
		       The  shell  may	be  compiled  to  read ~/.login	before
		       instead of after	~/.tcshrc and ~/.history; see the ver-
		       sion shell variable.
       ~/.cshdirs (+)  Read by login shells after ~/.login if savedirs is set,
		       but see also dirsfile.
       /etc/csh.logout Read by login shells at logout.	ConvexOS, Stellix  and
		       Intel  use  /etc/logout	and NeXTs use /etc/logout.std.
		       A/UX, AMIX, Cray	and IRIX have no equivalent in csh(1),
		       but  read  this	file in	tcsh anyway.  Solaris 2.x does
		       not have	it either, but tcsh reads /etc/.logout.	 (+)
       ~/.logout       Read by login shells at logout after /etc/csh.logout or
		       its equivalent.
       /bin/sh	       Used  to	 interpret  shell  scripts not starting	with a
		       `#'.
       /tmp/sh*	       Temporary file for `<<'.
       /etc/passwd     Source of home directories for `~name' substitutions.

       The order in which startup files	are read may differ if the  shell  was
       so compiled; see	Startup	and shutdown and the version shell variable.

NEW FEATURES (+)
       This  manual  describes tcsh as a single	entity,	but experienced	csh(1)
       users will want to pay special attention	to tcsh's new features.

       A command-line editor, which supports  GNU  Emacs  or  vi(1)-style  key
       bindings.  See The command-line editor and Editor commands.

       Programmable,  interactive word completion and listing.	See Completion
       and listing and the complete and	uncomplete builtin commands.

       Spelling	correction (q.v.) of filenames,	commands and variables.

       Editor commands (q.v.) which perform other useful functions in the mid-
       dle of typed commands, including	documentation lookup (run-help), quick
       editor restarting (run-fg-editor) and  command  resolution  (which-com-
       mand).

       An  enhanced  history  mechanism.  Events in the	history	list are time-
       stamped.	 See also the history command and its associated  shell	 vari-
       ables,  the  previously	undocumented `#' event specifier and new modi-
       fiers under History substitution, the *-history,	 history-search-*,  i-
       search-*,  vi-search-*  and  toggle-literal-history editor commands and
       the histlit shell variable.

       Enhanced	directory parsing and directory	stack handling.	 See  the  cd,
       pushd, popd and dirs commands and their associated shell	variables, the
       description of Directory	stack substitution, the	dirstack, owd and sym-
       links shell variables and the normalize-command and normalize-path edi-
       tor commands.

       Negation	in glob-patterns.  See Filename	substitution.

       New File	inquiry	operators (q.v.) and a	filetest  builtin  which  uses
       them.

       A  variety  of  Automatic,  periodic  and timed events (q.v.) including
       scheduled events, special aliases, automatic logout and terminal	 lock-
       ing, command timing and watching	for logins and logouts.

       Support for the Native Language System (see Native Language System sup-
       port), OS variant features (see OS variant support and  the  echo_style
       shell variable) and system-dependent file locations (see	FILES).

       Extensive terminal-management capabilities.  See	Terminal management.

       New  builtin  commands including	builtins, hup, ls-F, newgrp, printenv,
       which and where (q.v.).

       New variables that make useful  information  easily  available  to  the
       shell.	See  the  gid, loginsh,	oid, shlvl, tcsh, tty, uid and version
       shell variables and the HOST, REMOTEHOST, VENDOR, OSTYPE	 and  MACHTYPE
       environment variables.

       A new syntax for	including useful information in	the prompt string (see
       prompt).	 and special prompts for loops and  spelling  correction  (see
       prompt2 and prompt3).

       Read-only variables.  See Variable substitution.

BUGS
       When  a	suspended command is restarted,	the shell prints the directory
       it started in if	this is	different from the  current  directory.	  This
       can be misleading (i.e.,	wrong) as the job may have changed directories
       internally.

       Shell  builtin  functions  are  not   stoppable/restartable.    Command
       sequences  of the form `a ; b ; c' are also not handled gracefully when
       stopping	is attempted.  If you suspend `b', the shell will then immedi-
       ately  execute  `c'.   This  is especially noticeable if	this expansion
       results from an alias.  It suffices to place the	sequence  of  commands
       in ()'s to force	it to a	subshell, i.e.,	`( a ; b ; c )'.

       Control	over tty output	after processes	are started is primitive; per-
       haps this will inspire someone to  work	on  a  good  virtual  terminal
       interface.   In	a  virtual  terminal  interface	 much more interesting
       things could be done with output	control.

       Alias substitution is most often	used to	clumsily simulate shell	proce-
       dures; shell procedures should be provided rather than aliases.

       Commands	 within	 loops	are  not  placed in the	history	list.  Control
       structures should be parsed rather than being  recognized  as  built-in
       commands.   This	would allow control commands to	be placed anywhere, to
       be combined with	`|', and to be used with `&' and `;' metasyntax.

       foreach doesn't ignore here documents when looking for its end.

       It should be possible to	use the	`:' modifiers on the output of command
       substitutions.

       The  screen  update for lines longer than the screen width is very poor
       if the terminal cannot move the cursor up (i.e.,	terminal type `dumb').

       HPATH and NOREBIND don't	need to	be environment variables.

       Glob-patterns  which  do	 not use `?', `*' or `[]' or which use `{}' or
       `~' are not negated correctly.

       The single-command form of if  does  output  redirection	 even  if  the
       expression is false and the command is not executed.

       ls-F includes file identification characters when sorting filenames and
       does not	handle control characters in filenames	well.	It  cannot  be
       interrupted.

       Command substitution supports multiple commands and conditions, but not
       cycles or backward gotos.

       Report bugs at http://bugs.gw.com/, preferably with fixes.  If you want
       to  help	 maintain  and	test tcsh, send	mail to	tcsh-request@mx.gw.com
       with the	text `subscribe	tcsh' on a line	by itself in the body.

THE T IN TCSH
       In 1964,	DEC produced the PDP-6.	 The PDP-10 was	a later	re-implementa-
       tion.   It  was	re-christened  the DECsystem-10	in 1970	or so when DEC
       brought out the second model, the KI10.

       TENEX was created at Bolt, Beranek & Newman (a Cambridge, Massachusetts
       think  tank)  in	 1972  as an experiment	in demand-paged	virtual	memory
       operating systems.  They	built a	new pager for the DEC PDP-10 and  cre-
       ated the	OS to go with it.  It was extremely successful in academia.

       In  1975,  DEC  brought	out  a new model of the	PDP-10,	the KL10; they
       intended	to have	only a version of TENEX, which they had	licensed  from
       BBN,  for  the new box.	They called their version TOPS-20 (their capi-
       talization is trademarked).  A lot of  TOPS-10  users  (`The  OPerating
       System  for PDP-10') objected; thus DEC found themselves	supporting two
       incompatible systems on the same	hardware--but then there were 6	on the
       PDP-11!

       TENEX,  and  TOPS-20  to	 version 3, had	command	completion via a user-
       code-level subroutine library called ULTCMD.  With version 3, DEC moved
       all  that  capability  and more into the	monitor	(`kernel' for you Unix
       types), accessed	by the COMND% JSYS (`Jump to SYStem' instruction,  the
       supervisor call mechanism [are my IBM roots also	showing?]).

       The creator of tcsh was impressed by this feature and several others of
       TENEX and TOPS-20, and created a	version	of csh which mimicked them.

LIMITATIONS
       Words can be no longer than 1024	characters.

       The system limits argument lists	to 10240 characters.

       The number of arguments to a command which involves filename  expansion
       is  limited  to	1/6th  the number of characters	allowed	in an argument
       list.

       Command substitutions  may  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.

SEE ALSO
       csh(1), emacs(1), ls(1),	newgrp(1), sh(1), setpath(1), stty(1),	su(1),
       tset(1),	  vi(1),   x(1),  access(2),  execve(2),  fork(2),  killpg(2),
       pipe(2),	setrlimit(2), sigvec(2), stat(2), umask(2), vfork(2), wait(2),
       malloc(3),  setlocale(3),  tty(4),  a.out(5),  termcap(5),  environ(7),
       termio(7), Introduction to the C	Shell

VERSION
       This manual documents tcsh 6.15.00 (Astron) 2007-03-03.

AUTHORS
       William Joy
	 Original author of csh(1)
       J.E. Kulp, IIASA, Laxenburg, Austria
	 Job control and directory stack features
       Ken Greer, HP Labs, 1981
	 File name completion
       Mike Ellis, Fairchild, 1983
	 Command name recognition/completion
       Paul Placeway, Ohio State CIS Dept., 1983-1993
	 Command line editor, prompt routines, new glob	 syntax	 and  numerous
	 fixes and speedups
       Karl Kleinpaste,	CCI 1983-4
	 Special  aliases,  directory  stack  extraction  stuff,  login/logout
	 watch,	scheduled events, and the idea of the new prompt format
       Rayan Zachariassen, University of Toronto, 1984
	 ls-F and which	builtins and numerous  bug  fixes,  modifications  and
	 speedups
       Chris Kingsley, Caltech
	 Fast storage allocator	routines
       Chris Grevstad, TRW, 1987
	 Incorporated 4.3BSD csh into tcsh
       Christos	S. Zoulas, Cornell U. EE Dept.,	1987-94
	 Ports	 to   HPUX,   SVR2  and	 SVR3,	a  SysV	 version  of  getwd.c,
	 SHORT_STRINGS support and a new version of sh.glob.c
       James J Dempsey,	BBN, and Paul Placeway,	OSU, 1988
	 A/UX port
       Daniel Long, NNSC, 1988
	 wordchars
       Patrick Wolfe, Kuck and Associates, Inc., 1988
	 vi mode cleanup
       David C Lawrence, Rensselaer Polytechnic	Institute, 1989
	 autolist and ambiguous	completion listing
       Alec Wolman, DEC, 1989
	 Newlines in the prompt
       Matt Landau, BBN, 1989
	 ~/.tcshrc
       Ray Moody, Purdue Physics, 1989
	 Magic space bar history expansion
       Mordechai ????, Intel, 1989
	 printprompt() fixes and additions
       Kazuhiro	Honda, Dept. of	Computer Science, Keio University, 1989
	 Automatic spelling correction and prompt3
       Per Hedeland, Ellemtel, Sweden, 1990-
	 Various bugfixes, improvements	and manual updates
       Hans J. Albertsson (Sun Sweden)
	 ampm, settc and telltc
       Michael Bloom
	 Interrupt handling fixes
       Michael Fine, Digital Equipment Corp
	 Extended key support
       Eric Schnoebelen, Convex, 1990
	 Convex	support, lots of csh bug fixes,	save and restore of  directory
	 stack
       Ron Flax, Apple,	1990
	 A/UX 2.0 (re)port
       Dan Oscarsson, LTH Sweden, 1990
	 NLS support and simulated NLS support for non NLS sites, fixes
       Johan Widen, SICS Sweden, 1990
	 shlvl,	Mach support, correct-line, 8-bit printing
       Matt Day, Sanyo Icon, 1990
	 POSIX termio support, SysV limit fixes
       Jaap Vermeulen, Sequent,	1990-91
	 Vi mode fixes,	expand-line, window change fixes, Symmetry port
       Martin Boyer, Institut de recherche d'Hydro-Quebec, 1991
	 autolist  beeping  options, modified the history search to search for
	 the whole string from the beginning of	the line to the	cursor.
       Scott Krotz, Motorola, 1991
	 Minix port
       David Dawes, Sydney U. Australia, Physics Dept.,	1991
	 SVR4 job control fixes
       Jose Sousa, Interactive Systems Corp., 1991
	 Extended vi fixes and vi delete command
       Marc Horowitz, MIT, 1991
	 ANSIfication fixes, new exec hashing code, imake fixes, where
       Bruce Sterling Woodcock,	sterling@netcom.com, 1991-1995
	 ETA and Pyramid port, Makefile	and lint fixes,	ignoreeof=n  addition,
	 and various other portability changes and bug fixes
       Jeff Fink, 1992
	 complete-word-fwd and complete-word-back
       Harry C.	Pulley,	1992
	 Coherent port
       Andy Phillips, Mullard Space Science Lab	U.K., 1992
	 VMS-POSIX port
       Beto Appleton, IBM Corp., 1992
	 Walking  process  group fixes,	csh bug	fixes, POSIX file tests, POSIX
	 SIGHUP
       Scott Bolte, Cray Computer Corp., 1992
	 CSOS port
       Kaveh R.	Ghazi, Rutgers University, 1992
	 Tek, m88k, Titan and Masscomp ports and fixes.	 Added	autoconf  sup-
	 port.
       Mark Linderman, Cornell University, 1992
	 OS/2 port
       Mika Liljeberg, liljeber@kruuna.Helsinki.FI, 1992
	 Linux port
       Tim P. Starrin, NASA Langley Research Center Operations,	1993
	 Read-only variables
       Dave Schweisguth, Yale University, 1993-4
	 New man page and tcsh.man2html
       Larry Schwimmer,	Stanford University, 1993
	 AFS and HESIOD	patches
       Luke Mewburn, RMIT University, 1994-6
	 Enhanced directory printing in	prompt,	added ellipsis and rprompt.
       Edward Hutchins,	Silicon	Graphics Inc., 1996
	 Added implicit	cd.
       Martin Kraemer, 1997
	 Ported	to Siemens Nixdorf EBCDIC machine
       Amol Deshpande, Microsoft, 1997
	 Ported	 to  WIN32  (Windows/95	and Windows/NT); wrote all the missing
	 library and message catalog code to interface to Windows.
       Taga Nayuta, 1998
	 Color ls additions.

THANKS TO
       Bryan Dunlap, Clayton Elwell, Karl Kleinpaste, Bob Manson, Steve	Romig,
       Diana  Smetters,	Bob Sutterfield, Mark Verber, Elizabeth	Zwicky and all
       the other people	at Ohio	State for suggestions and encouragement

       All the people on the net, for putting up with, reporting bugs in,  and
       suggesting new additions	to each	and every version

       Richard M. Alderson III,	for writing the	`T in tcsh' section

Astron 6.15.00			 3 March 2007			       TCSH(1)

NAME | SYNOPSIS | DESCRIPTION | REFERENCE | ENVIRONMENT | FILES | NEW FEATURES (+) | BUGS | THE T IN TCSH | LIMITATIONS | SEE ALSO | VERSION | AUTHORS | THANKS TO

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