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TCSH(1)								       TCSH(1)

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

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

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

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

       The rest of the flag arguments are interpreted as follows:

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

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

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

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

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

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

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

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

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

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

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

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

       -s  Command input is taken from the standard input.

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

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

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

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

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

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

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

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

       Remaining arguments are placed in the argv shell variable.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       or

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

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

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

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

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

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

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

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

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

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

	   A_silly_file	   a-hyphenated-file	another_silly_file

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

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

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

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

	   > rm foo[tab]
	   > rm foo

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       spell-line (M-$)
	       Attempts to correct the spelling of each word in the input buf‐
	       fer,  like  spell-word, but ignores words whose first character
	       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  buf‐
	       fer.   See  also	 expand-history and the autoexpand shell vari‐
	       able.

       undefined-key (any unbound key)
	       Beeps.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       History substitutions introduce words from the history  list  into  the
       input  stream, making it easy to repeat commands, repeat arguments of a
       previous command in the current command, or fix	spelling  mistakes  in
       the  previous  command  with  little typing and a high degree of confi‐
       dence.

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

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

       An event specification can be

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       Input/output redirections are recognized before variable expansion, and
       are variable expanded separately.   Otherwise,  the  command  name  and
       entire  argument	 list  are expanded together.  It is thus possible for
       the first (command) word (to this point)	 to  generate  more  than  one
       word,  the  first  of  which  becomes the command name, and the rest of
       which become arguments.

       Unless enclosed in `"' or given the `:q' modifier the results of	 vari‐
       able  substitution  may eventually be command and filename substituted.
       Within `"', a variable whose value consists of multiple	words  expands
       to a (portion of a) single word, with the words of the variable's value
       separated by blanks.  When the `:q' modifier is applied to a  substitu‐
       tion  the  variable  will expand to multiple words with each word sepa‐
       rated by a blank and quoted to prevent later command or	filename  sub‐
       stitution.

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

       $name
       ${name} Substitutes the words of the value of variable name, each sepa‐
	       rated by a blank.  Braces insulate name from following  charac‐
	       ters which would otherwise be part of it.  Shell variables have
	       names consisting of letters and digits starting with a  letter.
	       The  underscore	character  is considered a letter.  If name is
	       not a shell variable, but is set in the environment, then  that
	       value  is returned (but some of the other forms given below are
	       not available in this case).
       $name[selector]
       ${name[selector]}
	       Substitutes only the selected words from	 the  value  of	 name.
	       The  selector  is subjected to `$' substitution and may consist
	       of a single number or two numbers  separated  by	 a  `-'.   The
	       first word of a variable's value is numbered `1'.  If the first
	       number of a range is omitted it defaults to `1'.	 If  the  last
	       member  of  a  range  is	 omitted it defaults to `$#name'.  The
	       selector `*' selects all words.	It is not an error for a range
	       to be empty if the second argument is omitted or in range.
       $0      Substitutes  the	 name  of the file from which command input is
	       being read.  An error occurs if the name is not known.
       $number
       ${number}
	       Equivalent to `$argv[number]'.
       $*      Equivalent to `$argv', which is equivalent to `$argv[*]'.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       Parenthesized commands are always executed in a subshell.

	   (cd; pwd); pwd

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

	   cd; pwd

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

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

       1.  If hashing is turned explicitly off via unhash.

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

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

       4.  If the command contains a `/'.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	   [1] 1234

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

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

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

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

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

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

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

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

       When you try to leave the shell while jobs are  stopped,	 you  will  be
       warned that `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] [name]
	       If a directory name  is	given,	changes	 the  shell's  working
	       directory to name.  If not, changes to home.  If name is `-' it
	       is interpreted as the previous  working	directory  (see	 Other
	       substitutions).	 (+) If name is not a subdirectory of the cur‐
	       rent directory (and does not begin with `/',  `./'  or  `../'),
	       each  component	of the variable cdpath is checked to see if it
	       has a subdirectory name.	 Finally, if all else fails  but  name
	       is  a  shell variable whose value begins with `/', then this is
	       tried to see if it is a directory.

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

	       See also the implicitcd shell variable.

       chdir   A synonym for the cd builtin command.

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

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

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

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

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

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

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

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

	       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
	       (allowed in only a shell script), causes the shell to exit on a
	       hangup  for  the remainder of the script.  See also Signal han‐
	       dling and the nohup builtin command.

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

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

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

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

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

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

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

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

	       filesize
		      the largest single file which can be created

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

	       stacksize
		      the maximum size	of  the	 automatically-extended	 stack
		      region

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

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

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

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

	       concurrency
		      the maximum number of threads for this process

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

	       maxproc
		      the maximum number of simultaneous  processes  for  this
		      user id

	       sbsize the maximum size of socket buffer usage for this user

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	       or may be relative to the current time:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       group (+)
	       The user's group name.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	       Here's the behavior with symlinks unset,

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       user    The user's login name.

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

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

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

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

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

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

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

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

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

		   set watch = (1 any any)

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

	       The who shell variable controls the format of watch reports.

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

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

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

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

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

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

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

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

       GROUP (+)
	       Equivalent to the group shell variable.

       HOME    Equivalent to the home shell variable.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       SHLVL (+)
	       Equivalent to the shlvl shell variable.

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

       TERM    Equivalent to the term shell variable.

       TERMCAP The terminal capability string.	See Terminal management.

       USER    Equivalent to the user shell variable.

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

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

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

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

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

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

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

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

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

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

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

       Negation in glob-patterns.  See Filename substitution.

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

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

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

       Extensive terminal-management capabilities.  See Terminal management.

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

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

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

       Read-only variables.  See Variable substitution.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

LIMITATIONS
       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 6.16.00 (Astron) 2008-09-30.

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 6.16.00		       30 September 2008		       TCSH(1)
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