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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 expect `(', `)', `|'
		   and	`>'  inside  l	and  r.	 The character `&' in the r is
		   replaced by l; `\' also quotes `&'.	If l is empty  (``''),
		   the l from a previous substitution 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 fol‐
		   lowed 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

	       swapsize
		      the maximum amount of swap space reserved	 or  used  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 [-hf] [resource]
	       Removes the limitation on resource or, if no resource is speci‐
	       fied,  all  resource  limitations.   With -h, the corresponding
	       hard limits are removed.	 Only  the  super-user	may  do	 this.
	       Note  that  unlimit may not exit successful, since most systems
	       do not allow descriptors to be unlimited.  With -f  errors  are
	       ignored.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

		   > set tperiod = 30
		   > alias periodic checknews

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

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

		   > alias precmd date

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

       postcmd Runs before each command gets executed.

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

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

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

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

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

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

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

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

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

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

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

       autoexpand (+)
	       If set, the expand-history editor command is invoked  automati‐
	       cally  before  each completion attempt. If this is set to only‐
	       history, then only history will be expanded and a  second  com‐
	       pletion will expand filenames.

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

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

       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 6.17.00 (Astron) 2009-07-10.

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 6.17.00			 10 July 2009			       TCSH(1)
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