Skip site navigation (1)Skip section navigation (2)

FreeBSD Man Pages

Man Page or Keyword Search:
Man Architecture
Apropos Keyword Search (all sections) Output format
home | help
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.

       If  the complete	shell variable is set to `Enhance', completion ignores
       case and	differences between a hyphen and an underscore word  separator
       only  when  the user types a lowercase character	or a hyphen.  Entering
       an uppercase character or an underscore will not	match the  correspond-
       ing   lowercase	 character  or	hyphen	word  separator.   Typing  `rm
       a--file[^D]' in the directory of	the previous example would still  list
       all   three   files,   but   typing   `rm  A--file'  would  match  only
       `A_silly_file'  and  typing   `rm   a__file[^D]'	  would	  match	  just
       `A_silly_file'  and  `another_silly_file'  because  the user explicitly
       used an uppercase or an underscore character.

       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 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  (unless  either  globdot  or  globstar or both are
       set(+)).	 The character `*' matches any string of characters, 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 globstar shell variable can be set to allow `**' or `***' as	a file
       glob  pattern  that  matches  any  string  of characters	including `/',
       recursively traversing any existing sub-directories.  For example,  `ls
       **.c'  will  list  all  the .c files in the current directory tree.  If
       used by itself, it will match match zero	or more	sub-directories	 (e.g.
       `ls  /usr/include/**/time.h'  will  list	any file named `time.h'	in the
       /usr/include directory tree; `ls	/usr/include/**time.h' will match  any
       file  in	 the  /usr/include  directory tree ending in `time.h'; and `ls
       /usr/include/**time**.h'	will match any .h file with `time' either in a
       subdirectory name or in the filename itself).  To prevent problems with
       recursion, the `**' glob-pattern	will not descend into a	symbolic  link
       containing a directory.	To override this, use `***' (+)

       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 `There are suspended	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] [I--] [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.  (+) Using -- forces a break  from  option  pro-
	       cessing so the next word	is taken as the	directory name even if
	       it begins with '-'. (+)

	       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.

	       command	invoked	 from `...` version has	additional environment
	       variable	set, the variable name is  COMMAND_LINE	 and  contains
	       (as  its	name indicates)	contents of the	current	(already typed
	       in) command line. One can  examine  and	use  contents  of  the
	       COMMAND_LINE  variable  in  her	custom	script	to  build more
	       sophisticated completions (see completion for  svn(1)  included
	       in this package).

	       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,
	       causes  the  non-interactive shell only to exit on a hangup for
	       the remainder of	the script.  See also Signal handling 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

	       vmemoryuse
		      the  maximum amount of virtual memory a process may have
		      allocated	to it at a given time (address space)

	       vmemoryuse
		      the maximum amount of virtual 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

	       swapsize
		      the maximum amount of swap space reserved	 or  used  for
		      this user

	       maxlocks
		      the maximum number of locks for this user

	       maxsignal
		      the maximum number of pending signals for	this user

	       maxmessage
		      the  maximum  number  of bytes in	POSIX mqueues for this
		      user

	       maxnice
		      the maximum nice priority	the user is allowed  to	 raise
		      mapped from [19...-20] to	[0...39] for this user

	       maxrtprio
		      the  maximum  realtime  priority for this	user maxrttime
		      the timeout for RT tasks in microseconds 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' or `g'  or  `gigabytes'  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.

	       If  maximum-use	 is  `unlimited',  then	 the limitation	on the
	       specified resource  is  removed	(this  is  equivalent  to  the
	       unlimit builtin command).

	       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	shell 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, causes the
	       non-interactive shell only 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
	       the autorehash shell variable is	not set	and new	 commands  are
	       added  to  directories  in  path	while you are logged in.  With
	       autorehash, a new command will be found	automatically,	except
	       in  the	special	 case  where  another command of the same name
	       which is	located	in a different directory already exists	in the
	       hash  table.   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 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 [-hf] [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.  With -f errors are
	       ignored.

       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\;\!#:q^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\;\!#:q^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. If this is set to only-
	       history,	then only history will be expanded and a  second  com-
	       pletion will expand filenames.

       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.

       autorehash (+)
	       If set, the internal hash table of the contents of the directo-
	       ries in the path	variable will be recomputed if	a  command  is
	       not  found  in the hash table.  In addition, the	list of	avail-
	       able commands will be rebuilt for each  command	completion  or
	       spelling	 correction  attempt if	set to `complete' or `correct'
	       respectively; if	set to `always', this will be  done  for  both
	       cases.

       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.).

       compat_expr (+)
	       If set, the shell will evaluate expressions right to left, like
	       the original csh.

       complete	(+)
	       If set to `igncase', the	completion becomes  case  insensitive.
	       If  set	to  `enhance',	completion  ignores case and considers
	       hyphens and underscores to be equivalent; it  will  also	 treat
	       periods,	 hyphens  and  underscores  (`.', `-' and `_') as word
	       separators.  If set to `Enhance', completion matches  uppercase
	       and  underscore characters explicitly and matches lowercase and
	       hyphens in a case-insensivite manner; it	 will  treat  periods,
	       hypens and underscores as word separators.

       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 effect 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>'.

       euid (+)
	       The user's effective user ID.

       euser (+)
	       The first matching  passwd  entry  name	corresponding  to  the
	       effective user ID.

       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.

       globdot (+)
	       If  set,	 wild-card glob	patterns will match files and directo-
	       ries beginning with `.' except for `.' and `..'

       globstar	(+)
	       If set, the `**'	and `***' file glob patterns  will  match  any
	       string of characters including `/' traversing any existing sub-
	       directories.  (e.g.  `ls	**.c' will list	all the	 .c  files  in
	       the  current directory tree).  If used by itself, it will match
	       match	zero	or    more    sub-directories	 (e.g.	   `ls
	       /usr/include/**/time.h'	will  list  any	file named `time.h' in
	       the    /usr/include     directory     tree;     whereas	   `ls
	       /usr/include/**time.h'  will match any file in the /usr/include
	       directory tree ending in	`time.h').  To prevent	problems  with
	       recursion,  the	`**' glob-pattern will not descend into	a sym-
	       bolic link containing a directory.  To override this, use `***'

       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    A  list	of  files  and directories to check for	incoming mail,
	       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.

       parseoctal
	       To  retain  compatibily	with  older versions numeric variables
	       starting	with 0 are not	interpreted  as	 octal.	 Setting  this
	       variable	enables	proper octal parsing.

       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.
	       %N  The effective 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, unless the variable
	       anyerror	is set,	and any	error in a  pipeline  or  a  backquote
	       expansion will be propagated (this is the default csh behavior,
	       and the current tcsh default).  If  it  terminated  abnormally,
	       then  0200 is added to the status.  Builtin commands which fail
	       return exit status `1', all other builtin commands return  sta-
	       tus `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.

       Control structures should be parsed rather  than	 being	recognized  as
       built-in	commands.  This	would allow control commands to	be placed any-
       where, to be combined with `|', and to be used with `&' and  `;'	 meta-
       syntax.

       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
       The system limits argument lists	to ARG_MAX 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 6.18.01 (Astron) 2012-02-14.

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 6.18.01		       14 February 2012			       TCSH(1)

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

Want to link to this manual page? Use this URL:
<http://www.freebsd.org/cgi/man.cgi?query=csh&sektion=1&manpath=FreeBSD+10.1-RELEASE>

home | help