1TCSH(1) General Commands Manual TCSH(1)
2
6 tcsh - C shell with file name completion and command line editing
7
9 tcsh [-bcdefFimnqstvVxX] [-Dname[=value]] [arg ...]
10 tcsh -l
11
13 tcsh is an enhanced but completely compatible version of the Berkeley
14 UNIX C shell, csh(1). It is a command language interpreter usable both
15 as an interactive login shell and a shell script command processor. It
16 includes a command-line editor (see The command-line editor), program‐
17 mable word completion (see Completion and listing), spelling correction
18 (see Spelling correction), a history mechanism (see History substitu‐
19 tion), job control (see Jobs) and a C-like syntax. The NEW FEATURES
20 section describes major enhancements of tcsh over csh(1). Throughout
21 this manual, features of tcsh not found in most csh(1) implementations
22 (specifically, the 4.4BSD csh) are labeled with `(+)', and features
23 which are present in csh(1) but not usually documented are labeled with
24 `(u)'.
25 Argument list processing
27 If the first argument (argument 0) to the shell is `-' then it is a
28 login shell. A login shell can be also specified by invoking the shell
29 with the -l flag as the only argument.
30 The rest of the flag arguments are interpreted as follows:
32 -b Forces a ``break'' from option processing, causing any further
34 shell arguments to be treated as non-option arguments. The remain‐
35 ing arguments will not be interpreted as shell options. This may
36 be used to pass options to a shell script without confusion or pos‐
37 sible subterfuge. The shell will not run a set-user ID script
38 without this option.
39 -c Commands are read from the following argument (which must be
41 present, and must be a single argument), stored in the command
42 shell variable for reference, and executed. Any remaining argu‐
43 ments are placed in the argv shell variable.
44 -d The shell loads the directory stack from ~/.cshdirs as described
46 under Startup and shutdown, whether or not it is a login shell. (+)
47 -Dname[=value]
49 Sets the environment variable name to value. (Domain/OS only) (+)
50 -e The shell exits if any invoked command terminates abnormally or
52 yields a non-zero exit status.
53 -f The shell does not load any resource or startup files, or perform
55 any command hashing, and thus starts faster.
56 -F The shell uses fork(2) instead of vfork(2) to spawn processes. (+)
58 -i The shell is interactive and prompts for its top-level input, even
60 if it appears to not be a terminal. Shells are interactive without
61 this option if their inputs and outputs are terminals.
62 -l The shell is a login shell. Applicable only if -l is the only flag
64 specified.
65 -m The shell loads ~/.tcshrc even if it does not belong to the effec‐
67 tive user. Newer versions of su(1) can pass -m to the shell. (+)
68 -n The shell parses commands but does not execute them. This aids in
70 debugging shell scripts.
71 -q The shell accepts SIGQUIT (see Signal handling) and behaves when it
73 is used under a debugger. Job control is disabled. (u)
74 -s Command input is taken from the standard input.
76 -t The shell reads and executes a single line of input. A `\' may be
78 used to escape the newline at the end of this line and continue
79 onto another line.
80 -v Sets the verbose shell variable, so that command input is echoed
82 after history substitution.
83 -x Sets the echo shell variable, so that commands are echoed immedi‐
85 ately before execution.
86 -V Sets the verbose shell variable even before executing ~/.tcshrc.
88 -X Is to -x as -V is to -v.
90 --help
92 Print a help message on the standard output and exit. (+)
93 --version
95 Print the version/platform/compilation options on the standard out‐
96 put and exit. This information is also contained in the version
97 shell variable. (+)
98 After processing of flag arguments, if arguments remain but none of the
100 -c, -i, -s, or -t options were given, the first argument is taken as
101 the name of a file of commands, or ``script'', to be executed. The
102 shell opens this file and saves its name for possible resubstitution by
103 `$0'. Because many systems use either the standard version 6 or ver‐
104 sion 7 shells whose shell scripts are not compatible with this shell,
105 the shell uses such a `standard' shell to execute a script whose first
106 character is not a `#', i.e., that does not start with a comment.
107 Remaining arguments are placed in the argv shell variable.
109 Startup and shutdown
111 A login shell begins by executing commands from the system files
112 /etc/csh.cshrc and /etc/csh.login. It then executes commands from
113 files in the user's home directory: first ~/.tcshrc (+) or, if
114 ~/.tcshrc is not found, ~/.cshrc, then the contents of ~/.history (or
115 the value of the histfile shell variable) are loaded into memory, then
116 ~/.login, and finally ~/.cshdirs (or the value of the dirsfile shell
117 variable) (+). The shell may read /etc/csh.login before instead of
118 after /etc/csh.cshrc, and ~/.login before instead of after ~/.tcshrc or
119 ~/.cshrc and ~/.history, if so compiled; see the version shell vari‐
120 able. (+)
121 Non-login shells read only /etc/csh.cshrc and ~/.tcshrc or ~/.cshrc on
123 startup.
124 For examples of startup files, please consult http://tcshrc.source‐
126 forge.net.
127 Commands like stty(1) and tset(1), which need be run only once per
129 login, usually go in one's ~/.login file. Users who need to use the
130 same set of files with both csh(1) and tcsh can have only a ~/.cshrc
131 which checks for the existence of the tcsh shell variable (q.v.) before
132 using tcsh-specific commands, or can have both a ~/.cshrc and a
133 ~/.tcshrc which sources (see the builtin command) ~/.cshrc. The rest
134 of this manual uses `~/.tcshrc' to mean `~/.tcshrc or, if ~/.tcshrc is
135 not found, ~/.cshrc'.
136 In the normal case, the shell begins reading commands from the termi‐
138 nal, prompting with `> '. (Processing of arguments and the use of the
139 shell to process files containing command scripts are described later.)
140 The shell repeatedly reads a line of command input, breaks it into
141 words, places it on the command history list, parses it and executes
142 each command in the line.
143 One can log out by typing `^D' on an empty line, `logout' or `login' or
145 via the shell's autologout mechanism (see the autologout shell vari‐
146 able). When a login shell terminates it sets the logout shell variable
147 to `normal' or `automatic' as appropriate, then executes commands from
148 the files /etc/csh.logout and ~/.logout. The shell may drop DTR on
149 logout if so compiled; see the version shell variable.
150 The names of the system login and logout files vary from system to sys‐
152 tem for compatibility with different csh(1) variants; see FILES.
153 Editing
155 We first describe The command-line editor. The Completion and listing
156 and Spelling correction sections describe two sets of functionality
157 that are implemented as editor commands but which deserve their own
158 treatment. Finally, Editor commands lists and describes the editor
159 commands specific to the shell and their default bindings.
160 The command-line editor (+)
162 Command-line input can be edited using key sequences much like those
163 used in emacs(1) or vi(1). The editor is active only when the edit
164 shell variable is set, which it is by default in interactive shells.
165 The bindkey builtin can display and change key bindings.
166 emacs(1)-style key bindings are used by default (unless the shell was
167 compiled otherwise; see the version shell variable), but bindkey can
168 change the key bindings to vi(1)-style bindings en masse.
169 The shell always binds the arrow keys (as defined in the TERMCAP envi‐
171 ronment variable) to
172 down down-history
174 up up-history
175 left backward-char
176 right forward-char
177 unless doing so would alter another single-character binding. One can
179 set the arrow key escape sequences to the empty string with settc to
180 prevent these bindings. The ANSI/VT100 sequences for arrow keys are
181 always bound.
182 Other key bindings are, for the most part, what emacs(1) and vi(1)
184 users would expect and can easily be displayed by bindkey, so there is
185 no need to list them here. Likewise, bindkey can list the editor com‐
186 mands with a short description of each. Certain key bindings have dif‐
187 ferent behavior depending if emacs(1) or vi(1) style bindings are being
188 used; see vimode for more information.
189 Note that editor commands do not have the same notion of a ``word'' as
191 does the shell. The editor delimits words with any non-alphanumeric
192 characters not in the shell variable wordchars, while the shell recog‐
193 nizes only whitespace and some of the characters with special meanings
194 to it, listed under Lexical structure.
195 Completion and listing (+)
197 The shell is often able to complete words when given a unique abbrevia‐
198 tion. Type part of a word (for example `ls /usr/lost') and hit the tab
199 key to run the complete-word editor command. The shell completes the
200 filename `/usr/lost' to `/usr/lost+found/', replacing the incomplete
201 word with the complete word in the input buffer. (Note the terminal
202 `/'; completion adds a `/' to the end of completed directories and a
203 space to the end of other completed words, to speed typing and provide
204 a visual indicator of successful completion. The addsuffix shell vari‐
205 able can be unset to prevent this.) If no match is found (perhaps
206 `/usr/lost+found' doesn't exist), the terminal bell rings. If the word
207 is already complete (perhaps there is a `/usr/lost' on your system, or
208 perhaps you were thinking too far ahead and typed the whole thing) a
209 `/' or space is added to the end if it isn't already there.
210 Completion works anywhere in the line, not at just the end; completed
212 text pushes the rest of the line to the right. Completion in the mid‐
213 dle of a word often results in leftover characters to the right of the
214 cursor that need to be deleted.
215 Commands and variables can be completed in much the same way. For
217 example, typing `em[tab]' would complete `em' to `emacs' if emacs were
218 the only command on your system beginning with `em'. Completion can
219 find a command in any directory in path or if given a full pathname.
220 Typing `echo $ar[tab]' would complete `$ar' to `$argv' if no other
221 variable began with `ar'.
222 The shell parses the input buffer to determine whether the word you
224 want to complete should be completed as a filename, command or vari‐
225 able. The first word in the buffer and the first word following `;',
226 `|', `|&', `&&' or `||' is considered to be a command. A word begin‐
227 ning with `$' is considered to be a variable. Anything else is a file‐
228 name. An empty line is `completed' as a filename.
229 You can list the possible completions of a word at any time by typing
231 `^D' to run the delete-char-or-list-or-eof editor command. The shell
232 lists the possible completions using the ls-F builtin (q.v.) and re‐
233 prints the prompt and unfinished command line, for example:
234 > ls /usr/l[^D]
236 lbin/ lib/ local/ lost+found/
237 > ls /usr/l
238 If the autolist shell variable is set, the shell lists the remaining
240 choices (if any) whenever completion fails:
241 > set autolist
243 > nm /usr/lib/libt[tab]
244 libtermcap.a@ libtermlib.a@
245 > nm /usr/lib/libterm
246 If autolist is set to `ambiguous', choices are listed only when comple‐
248 tion fails and adds no new characters to the word being completed.
249 A filename to be completed can contain variables, your own or others'
251 home directories abbreviated with `~' (see Filename substitution) and
252 directory stack entries abbreviated with `=' (see Directory stack sub‐
253 stitution). For example,
254 > ls ~k[^D]
256 kahn kas kellogg
257 > ls ~ke[tab]
258 > ls ~kellogg/
259 or
261 > set local = /usr/local
263 > ls $lo[tab]
264 > ls $local/[^D]
265 bin/ etc/ lib/ man/ src/
266 > ls $local/
267 Note that variables can also be expanded explicitly with the expand-
269 variables editor command.
270 delete-char-or-list-or-eof lists at only the end of the line; in the
272 middle of a line it deletes the character under the cursor and on an
273 empty line it logs one out or, if ignoreeof is set, does nothing.
274 `M-^D', bound to the editor command list-choices, lists completion pos‐
275 sibilities anywhere on a line, and list-choices (or any one of the
276 related editor commands that do or don't delete, list and/or log out,
277 listed under delete-char-or-list-or-eof) can be bound to `^D' with the
278 bindkey builtin command if so desired.
279 The complete-word-fwd and complete-word-back editor commands (not bound
281 to any keys by default) can be used to cycle up and down through the
282 list of possible completions, replacing the current word with the next
283 or previous word in the list.
284 The shell variable fignore can be set to a list of suffixes to be
286 ignored by completion. Consider the following:
287 > ls
289 Makefile condiments.h~ main.o side.c
290 README main.c meal side.o
291 condiments.h main.c~
292 > set fignore = (.o \~)
293 > emacs ma[^D]
294 main.c main.c~ main.o
295 > emacs ma[tab]
296 > emacs main.c
297 `main.c~' and `main.o' are ignored by completion (but not listing),
299 because they end in suffixes in fignore. Note that a `\' was needed in
300 front of `~' to prevent it from being expanded to home as described
301 under Filename substitution. fignore is ignored if only one completion
302 is possible.
303 If the complete shell variable is set to `enhance', completion 1)
305 ignores case and 2) considers periods, hyphens and underscores (`.',
306 `-' and `_') to be word separators and hyphens and underscores to be
307 equivalent. If you had the following files
308 comp.lang.c comp.lang.perl comp.std.c++
310 comp.lang.c++ comp.std.c
311 and typed `mail -f c.l.c[tab]', it would be completed to `mail -f
313 comp.lang.c', and ^D would list `comp.lang.c' and `comp.lang.c++'.
314 `mail -f c..c++[^D]' would list `comp.lang.c++' and `comp.std.c++'.
315 Typing `rm a--file[^D]' in the following directory
316 A_silly_file a-hyphenated-file another_silly_file
318 would list all three files, because case is ignored and hyphens and
320 underscores are equivalent. Periods, however, are not equivalent to
321 hyphens or underscores.
322 If the complete shell variable is set to `Enhance', completion ignores
324 case and differences between a hyphen and an underscore word separator
325 only when the user types a lowercase character or a hyphen. Entering
326 an uppercase character or an underscore will not match the correspond‐
327 ing lowercase character or hyphen word separator. Typing `rm
328 a--file[^D]' in the directory of the previous example would still list
329 all three files, but typing `rm A--file' would match only
330 `A_silly_file' and typing `rm a__file[^D]' would match just
331 `A_silly_file' and `another_silly_file' because the user explicitly
332 used an uppercase or an underscore character.
333 Completion and listing are affected by several other shell variables:
335 recexact can be set to complete on the shortest possible unique match,
336 even if more typing might result in a longer match:
337 > ls
339 fodder foo food foonly
340 > set recexact
341 > rm fo[tab]
342 just beeps, because `fo' could expand to `fod' or `foo', but if we type
344 another `o',
345 > rm foo[tab]
347 > rm foo
348 the completion completes on `foo', even though `food' and `foonly' also
350 match. autoexpand can be set to run the expand-history editor command
351 before each completion attempt, autocorrect can be set to spelling-cor‐
352 rect the word to be completed (see Spelling correction) before each
353 completion attempt and correct can be set to complete commands automat‐
354 ically after one hits `return'. matchbeep can be set to make comple‐
355 tion beep or not beep in a variety of situations, and nobeep can be set
356 to never beep at all. nostat can be set to a list of directories
357 and/or patterns that match directories to prevent the completion mecha‐
358 nism from stat(2)ing those directories. listmax and listmaxrows can be
359 set to limit the number of items and rows (respectively) that are
360 listed without asking first. recognize_only_executables can be set to
361 make the shell list only executables when listing commands, but it is
362 quite slow.
363 Finally, the complete builtin command can be used to tell the shell how
365 to complete words other than filenames, commands and variables. Com‐
366 pletion and listing do not work on glob-patterns (see Filename substi‐
367 tution), but the list-glob and expand-glob editor commands perform
368 equivalent functions for glob-patterns.
369 Spelling correction (+)
371 The shell can sometimes correct the spelling of filenames, commands and
372 variable names as well as completing and listing them.
373 Individual words can be spelling-corrected with the spell-word editor
375 command (usually bound to M-s and M-S) and the entire input buffer with
376 spell-line (usually bound to M-$). The correct shell variable can be
377 set to `cmd' to correct the command name or `all' to correct the entire
378 line each time return is typed, and autocorrect can be set to correct
379 the word to be completed before each completion attempt.
380 When spelling correction is invoked in any of these ways and the shell
382 thinks that any part of the command line is misspelled, it prompts with
383 the corrected line:
384 > set correct = cmd
386 > lz /usr/bin
387 CORRECT>ls /usr/bin (y|n|e|a)?
388 One can answer `y' or space to execute the corrected line, `e' to leave
390 the uncorrected command in the input buffer, `a' to abort the command
391 as if `^C' had been hit, and anything else to execute the original line
392 unchanged.
393 Spelling correction recognizes user-defined completions (see the com‐
395 plete builtin command). If an input word in a position for which a
396 completion is defined resembles a word in the completion list, spelling
397 correction registers a misspelling and suggests the latter word as a
398 correction. However, if the input word does not match any of the pos‐
399 sible completions for that position, spelling correction does not reg‐
400 ister a misspelling.
401 Like completion, spelling correction works anywhere in the line, push‐
403 ing the rest of the line to the right and possibly leaving extra char‐
404 acters to the right of the cursor.
405 Editor commands (+)
407 `bindkey' lists key bindings and `bindkey -l' lists and briefly
408 describes editor commands. Only new or especially interesting editor
409 commands are described here. See emacs(1) and vi(1) for descriptions
410 of each editor's key bindings.
411 The character or characters to which each command is bound by default
413 is given in parentheses. `^character' means a control character and
414 `M-character' a meta character, typed as escape-character on terminals
415 without a meta key. Case counts, but commands that are bound to let‐
416 ters by default are bound to both lower- and uppercase letters for con‐
417 venience.
418 backward-char (^B, left)
420 Move back a character. Cursor behavior modified by vimode.
421 backward-delete-word (M-^H, M-^?)
423 Cut from beginning of current word to cursor - saved in cut
424 buffer. Word boundary behavior modified by vimode.
425 backward-word (M-b, M-B)
427 Move to beginning of current word. Word boundary and cursor
428 behavior modified by vimode.
429 beginning-of-line (^A, home)
431 Move to beginning of line. Cursor behavior modified by vimode.
432 capitalize-word (M-c, M-C)
434 Capitalize the characters from cursor to end of current word.
435 Word boundary behavior modified by vimode.
436 complete-word (tab)
438 Completes a word as described under Completion and listing.
439 complete-word-back (not bound)
441 Like complete-word-fwd, but steps up from the end of the list.
442 complete-word-fwd (not bound)
444 Replaces the current word with the first word in the list of
445 possible completions. May be repeated to step down through the
446 list. At the end of the list, beeps and reverts to the incom‐
447 plete word.
448 complete-word-raw (^X-tab)
450 Like complete-word, but ignores user-defined completions.
451 copy-prev-word (M-^_)
453 Copies the previous word in the current line into the input
454 buffer. See also insert-last-word. Word boundary behavior
455 modified by vimode.
456 dabbrev-expand (M-/)
458 Expands the current word to the most recent preceding one for
459 which the current is a leading substring, wrapping around the
460 history list (once) if necessary. Repeating dabbrev-expand
461 without any intervening typing changes to the next previous
462 word etc., skipping identical matches much like history-search-
463 backward does.
464 delete-char (not bound)
466 Deletes the character under the cursor. See also delete-char-
467 or-list-or-eof. Cursor behavior modified by vimode.
468 delete-char-or-eof (not bound)
470 Does delete-char if there is a character under the cursor or
471 end-of-file on an empty line. See also delete-char-or-list-or-
472 eof. Cursor behavior modified by vimode.
473 delete-char-or-list (not bound)
475 Does delete-char if there is a character under the cursor or
476 list-choices at the end of the line. See also delete-char-or-
477 list-or-eof.
478 delete-char-or-list-or-eof (^D)
480 Does delete-char if there is a character under the cursor,
481 list-choices at the end of the line or end-of-file on an empty
482 line. See also those three commands, each of which does only a
483 single action, and delete-char-or-eof, delete-char-or-list and
484 list-or-eof, each of which does a different two out of the
485 three.
486 delete-word (M-d, M-D)
488 Cut from cursor to end of current word - save in cut buffer.
489 Word boundary behavior modified by vimode.
490 down-history (down-arrow, ^N)
492 Like up-history, but steps down, stopping at the original input
493 line.
494 downcase-word (M-l, M-L)
496 Lowercase the characters from cursor to end of current word.
497 Word boundary behavior modified by vimode.
498 end-of-file (not bound)
500 Signals an end of file, causing the shell to exit unless the
501 ignoreeof shell variable (q.v.) is set to prevent this. See
502 also delete-char-or-list-or-eof.
503 end-of-line (^E, end)
505 Move cursor to end of line. Cursor behavior modified by
506 vimode.
507 expand-history (M-space)
509 Expands history substitutions in the current word. See History
510 substitution. See also magic-space, toggle-literal-history and
511 the autoexpand shell variable.
512 expand-glob (^X-*)
514 Expands the glob-pattern to the left of the cursor. See File‐
515 name substitution.
516 expand-line (not bound)
518 Like expand-history, but expands history substitutions in each
519 word in the input buffer.
520 expand-variables (^X-$)
522 Expands the variable to the left of the cursor. See Variable
523 substitution.
524 forward-char (^F, right)
526 Move forward one character. Cursor behavior modified by
527 vimode.
528 forward-word (M-f, M-F)
530 Move forward to end of current word. Word boundary and cursor
531 behavior modified by vimode.
532 history-search-backward (M-p, M-P)
534 Searches backwards through the history list for a command
535 beginning with the current contents of the input buffer up to
536 the cursor and copies it into the input buffer. The search
537 string may be a glob-pattern (see Filename substitution) con‐
538 taining `*', `?', `[]' or `{}'. up-history and down-history
539 will proceed from the appropriate point in the history list.
540 Emacs mode only. See also history-search-forward and i-search-
541 back.
542 history-search-forward (M-n, M-N)
544 Like history-search-backward, but searches forward.
545 i-search-back (not bound)
547 Searches backward like history-search-backward, copies the
548 first match into the input buffer with the cursor positioned at
549 the end of the pattern, and prompts with `bck: ' and the first
550 match. Additional characters may be typed to extend the
551 search, i-search-back may be typed to continue searching with
552 the same pattern, wrapping around the history list if neces‐
553 sary, (i-search-back must be bound to a single character for
554 this to work) or one of the following special characters may be
555 typed:
556 ^W Appends the rest of the word under the cursor to
558 the search pattern.
559 delete (or any character bound to backward-delete-char)
560 Undoes the effect of the last character typed and
561 deletes a character from the search pattern if
562 appropriate.
563 ^G If the previous search was successful, aborts the
564 entire search. If not, goes back to the last suc‐
565 cessful search.
566 escape Ends the search, leaving the current line in the
567 input buffer.
568 Any other character not bound to self-insert-command terminates
570 the search, leaving the current line in the input buffer, and
571 is then interpreted as normal input. In particular, a carriage
572 return causes the current line to be executed. See also i-
573 search-fwd and history-search-backward. Word boundary behavior
574 modified by vimode.
575 i-search-fwd (not bound)
577 Like i-search-back, but searches forward. Word boundary behav‐
578 ior modified by vimode.
579 insert-last-word (M-_)
581 Inserts the last word of the previous input line (`!$') into
582 the input buffer. See also copy-prev-word.
583 list-choices (M-^D)
585 Lists completion possibilities as described under Completion
586 and listing. See also delete-char-or-list-or-eof and list-
587 choices-raw.
588 list-choices-raw (^X-^D)
590 Like list-choices, but ignores user-defined completions.
591 list-glob (^X-g, ^X-G)
593 Lists (via the ls-F builtin) matches to the glob-pattern (see
594 Filename substitution) to the left of the cursor.
595 list-or-eof (not bound)
597 Does list-choices or end-of-file on an empty line. See also
598 delete-char-or-list-or-eof.
599 magic-space (not bound)
601 Expands history substitutions in the current line, like expand-
602 history, and inserts a space. magic-space is designed to be
603 bound to the space bar, but is not bound by default.
604 normalize-command (^X-?)
606 Searches for the current word in PATH and, if it is found,
607 replaces it with the full path to the executable. Special
608 characters are quoted. Aliases are expanded and quoted but
609 commands within aliases are not. This command is useful with
610 commands that take commands as arguments, e.g., `dbx' and `sh
611 -x'.
612 normalize-path (^X-n, ^X-N)
614 Expands the current word as described under the `expand' set‐
615 ting of the symlinks shell variable.
616 overwrite-mode (unbound)
618 Toggles between input and overwrite modes.
619 run-fg-editor (M-^Z)
621 Saves the current input line and looks for a stopped job where
622 the file name portion of its first word is found in the editors
623 shell variable. If editors is not set, then the file name por‐
624 tion of the EDITOR environment variable (`ed' if unset) and the
625 VISUAL environment variable (`vi' if unset) will be used. If
626 such a job is found, it is restarted as if `fg %job' had been
627 typed. This is used to toggle back and forth between an editor
628 and the shell easily. Some people bind this command to `^Z' so
629 they can do this even more easily.
630 run-help (M-h, M-H)
632 Searches for documentation on the current command, using the
633 same notion of `current command' as the completion routines,
634 and prints it. There is no way to use a pager; run-help is
635 designed for short help files. If the special alias helpcom‐
636 mand is defined, it is run with the command name as a sole
637 argument. Else, documentation should be in a file named com‐
638 mand.help, command.1, command.6, command.8 or command, which
639 should be in one of the directories listed in the HPATH envi‐
640 ronment variable. If there is more than one help file only the
641 first is printed.
642 self-insert-command (text characters)
644 In insert mode (the default), inserts the typed character into
645 the input line after the character under the cursor. In over‐
646 write mode, replaces the character under the cursor with the
647 typed character. The input mode is normally preserved between
648 lines, but the inputmode shell variable can be set to `insert'
649 or `overwrite' to put the editor in that mode at the beginning
650 of each line. See also overwrite-mode.
651 sequence-lead-in (arrow prefix, meta prefix, ^X)
653 Indicates that the following characters are part of a multi-key
654 sequence. Binding a command to a multi-key sequence really
655 creates two bindings: the first character to sequence-lead-in
656 and the whole sequence to the command. All sequences beginning
657 with a character bound to sequence-lead-in are effectively
658 bound to undefined-key unless bound to another command.
659 spell-line (M-$)
661 Attempts to correct the spelling of each word in the input buf‐
662 fer, like spell-word, but ignores words whose first character
663 is one of `-', `!', `^' or `%', or which contain `\', `*' or
664 `?', to avoid problems with switches, substitutions and the
665 like. See Spelling correction.
666 spell-word (M-s, M-S)
668 Attempts to correct the spelling of the current word as
669 described under Spelling correction. Checks each component of
670 a word which appears to be a pathname.
671 toggle-literal-history (M-r, M-R)
673 Expands or `unexpands' history substitutions in the input buf‐
674 fer. See also expand-history and the autoexpand shell vari‐
675 able.
676 undefined-key (any unbound key)
678 Beeps.
679 up-history (up-arrow, ^P)
681 Copies the previous entry in the history list into the input
682 buffer. If histlit is set, uses the literal form of the entry.
683 May be repeated to step up through the history list, stopping
684 at the top.
685 upcase-word (M-u, M-U)
687 Uppercase the characters from cursor to end of current word.
688 Word boundary behavior modified by vimode.
689 vi-beginning-of-next-word (not bound)
691 Vi goto the beginning of next word. Word boundary and cursor
692 behavior modified by vimode.
693 vi-eword (not bound)
695 Vi move to the end of the current word. Word boundary behavior
696 modified by vimode.
697 vi-search-back (?)
699 Prompts with `?' for a search string (which may be a glob-pat‐
700 tern, as with history-search-backward), searches for it and
701 copies it into the input buffer. The bell rings if no match is
702 found. Hitting return ends the search and leaves the last
703 match in the input buffer. Hitting escape ends the search and
704 executes the match. vi mode only.
705 vi-search-fwd (/)
707 Like vi-search-back, but searches forward.
708 which-command (M-?)
710 Does a which (see the description of the builtin command) on
711 the first word of the input buffer.
712 yank-pop (M-y)
714 When executed immediately after a yank or another yank-pop,
715 replaces the yanked string with the next previous string from
716 the killring. This also has the effect of rotating the kill‐
717 ring, such that this string will be considered the most
718 recently killed by a later yank command. Repeating yank-pop
719 will cycle through the killring any number of times.
720 Lexical structure
722 The shell splits input lines into words at blanks and tabs. The spe‐
723 cial characters `&', `|', `;', `<', `>', `(', and `)' and the doubled
724 characters `&&', `||', `<<' and `>>' are always separate words, whether
725 or not they are surrounded by whitespace.
726 When the shell's input is not a terminal, the character `#' is taken to
728 begin a comment. Each `#' and the rest of the input line on which it
729 appears is discarded before further parsing.
730 A special character (including a blank or tab) may be prevented from
732 having its special meaning, and possibly made part of another word, by
733 preceding it with a backslash (`\') or enclosing it in single (`''),
734 double (`"') or backward (``') quotes. When not otherwise quoted a
735 newline preceded by a `\' is equivalent to a blank, but inside quotes
736 this sequence results in a newline.
737 Furthermore, all Substitutions (see below) except History substitution
739 can be prevented by enclosing the strings (or parts of strings) in
740 which they appear with single quotes or by quoting the crucial charac‐
741 ter(s) (e.g., `$' or ``' for Variable substitution or Command substitu‐
742 tion respectively) with `\'. (Alias substitution is no exception:
743 quoting in any way any character of a word for which an alias has been
744 defined prevents substitution of the alias. The usual way of quoting
745 an alias is to precede it with a backslash.) History substitution is
746 prevented by backslashes but not by single quotes. Strings quoted with
747 double or backward quotes undergo Variable substitution and Command
748 substitution, but other substitutions are prevented.
749 Text inside single or double quotes becomes a single word (or part of
751 one). Metacharacters in these strings, including blanks and tabs, do
752 not form separate words. Only in one special case (see Command substi‐
753 tution below) can a double-quoted string yield parts of more than one
754 word; single-quoted strings never do. Backward quotes are special:
755 they signal Command substitution (q.v.), which may result in more than
756 one word.
757 Quoting complex strings, particularly strings which themselves contain
759 quoting characters, can be confusing. Remember that quotes need not be
760 used as they are in human writing! It may be easier to quote not an
761 entire string, but only those parts of the string which need quoting,
762 using different types of quoting to do so if appropriate.
763 The backslash_quote shell variable (q.v.) can be set to make back‐
765 slashes always quote `\', `'', and `"'. (+) This may make complex
766 quoting tasks easier, but it can cause syntax errors in csh(1) scripts.
767 Substitutions
769 We now describe the various transformations the shell performs on the
770 input in the order in which they occur. We note in passing the data
771 structures involved and the commands and variables which affect them.
772 Remember that substitutions can be prevented by quoting as described
773 under Lexical structure.
774 History substitution
776 Each command, or ``event'', input from the terminal is saved in the
777 history list. The previous command is always saved, and the history
778 shell variable can be set to a number to save that many commands. The
779 histdup shell variable can be set to not save duplicate events or con‐
780 secutive duplicate events.
781 Saved commands are numbered sequentially from 1 and stamped with the
783 time. It is not usually necessary to use event numbers, but the cur‐
784 rent event number can be made part of the prompt by placing an `!' in
785 the prompt shell variable.
786 The shell actually saves history in expanded and literal (unexpanded)
788 forms. If the histlit shell variable is set, commands that display and
789 store history use the literal form.
790 The history builtin command can print, store in a file, restore and
792 clear the history list at any time, and the savehist and histfile shell
793 variables can be set to store the history list automatically on logout
794 and restore it on login.
795 History substitutions introduce words from the history list into the
797 input stream, making it easy to repeat commands, repeat arguments of a
798 previous command in the current command, or fix spelling mistakes in
799 the previous command with little typing and a high degree of confi‐
800 dence.
801 History substitutions begin with the character `!'. They may begin
803 anywhere in the input stream, but they do not nest. The `!' may be
804 preceded by a `\' to prevent its special meaning; for convenience, a
805 `!' is passed unchanged when it is followed by a blank, tab, newline,
806 `=' or `('. History substitutions also occur when an input line begins
807 with `^'. This special abbreviation will be described later. The
808 characters used to signal history substitution (`!' and `^') can be
809 changed by setting the histchars shell variable. Any input line which
810 contains a history substitution is printed before it is executed.
811 A history substitution may have an ``event specification'', which indi‐
813 cates the event from which words are to be taken, a ``word designa‐
814 tor'', which selects particular words from the chosen event, and/or a
815 ``modifier'', which manipulates the selected words.
816 An event specification can be
818 n A number, referring to a particular event
820 -n An offset, referring to the event n before the current
821 event
822 # The current event. This should be used carefully in
823 csh(1), where there is no check for recursion. tcsh allows
824 10 levels of recursion. (+)
825 ! The previous event (equivalent to `-1')
826 s The most recent event whose first word begins with the
827 string s
828 ?s? The most recent event which contains the string s. The
829 second `?' can be omitted if it is immediately followed by
830 a newline.
831 For example, consider this bit of someone's history list:
833 9 8:30 nroff -man wumpus.man
835 10 8:31 cp wumpus.man wumpus.man.old
836 11 8:36 vi wumpus.man
837 12 8:37 diff wumpus.man.old wumpus.man
838 The commands are shown with their event numbers and time stamps. The
840 current event, which we haven't typed in yet, is event 13. `!11' and
841 `!-2' refer to event 11. `!!' refers to the previous event, 12. `!!'
842 can be abbreviated `!' if it is followed by `:' (`:' is described
843 below). `!n' refers to event 9, which begins with `n'. `!?old?' also
844 refers to event 12, which contains `old'. Without word designators or
845 modifiers history references simply expand to the entire event, so we
846 might type `!cp' to redo the copy command or `!!|more' if the `diff'
847 output scrolled off the top of the screen.
848 History references may be insulated from the surrounding text with
850 braces if necessary. For example, `!vdoc' would look for a command
851 beginning with `vdoc', and, in this example, not find one, but
852 `!{v}doc' would expand unambiguously to `vi wumpus.mandoc'. Even in
853 braces, history substitutions do not nest.
854 (+) While csh(1) expands, for example, `!3d' to event 3 with the letter
856 `d' appended to it, tcsh expands it to the last event beginning with
857 `3d'; only completely numeric arguments are treated as event numbers.
858 This makes it possible to recall events beginning with numbers. To
859 expand `!3d' as in csh(1) say `!{3}d'.
860 To select words from an event we can follow the event specification by
862 a `:' and a designator for the desired words. The words of an input
863 line are numbered from 0, the first (usually command) word being 0, the
864 second word (first argument) being 1, etc. The basic word designators
865 are:
866 0 The first (command) word
868 n The nth argument
869 ^ The first argument, equivalent to `1'
870 $ The last argument
871 % The word matched by an ?s? search
872 x-y A range of words
873 -y Equivalent to `0-y'
874 * Equivalent to `^-$', but returns nothing if the event con‐
875 tains only 1 word
876 x* Equivalent to `x-$'
877 x- Equivalent to `x*', but omitting the last word (`$')
878 Selected words are inserted into the command line separated by single
880 blanks. For example, the `diff' command in the previous example might
881 have been typed as `diff !!:1.old !!:1' (using `:1' to select the first
882 argument from the previous event) or `diff !-2:2 !-2:1' to select and
883 swap the arguments from the `cp' command. If we didn't care about the
884 order of the `diff' we might have said `diff !-2:1-2' or simply `diff
885 !-2:*'. The `cp' command might have been written `cp wumpus.man
886 !#:1.old', using `#' to refer to the current event. `!n:- hurkle.man'
887 would reuse the first two words from the `nroff' command to say `nroff
888 -man hurkle.man'.
889 The `:' separating the event specification from the word designator can
891 be omitted if the argument selector begins with a `^', `$', `*', `%' or
892 `-'. For example, our `diff' command might have been `diff !!^.old
893 !!^' or, equivalently, `diff !!$.old !!$'. However, if `!!' is abbre‐
894 viated `!', an argument selector beginning with `-' will be interpreted
895 as an event specification.
896 A history reference may have a word designator but no event specifica‐
898 tion. It then references the previous command. Continuing our `diff'
899 example, we could have said simply `diff !^.old !^' or, to get the
900 arguments in the opposite order, just `diff !*'.
901 The word or words in a history reference can be edited, or ``modi‐
903 fied'', by following it with one or more modifiers, each preceded by a
904 `:':
905 h Remove a trailing pathname component, leaving the head.
907 t Remove all leading pathname components, leaving the tail.
908 r Remove a filename extension `.xxx', leaving the root name.
909 e Remove all but the extension.
910 u Uppercase the first lowercase letter.
911 l Lowercase the first uppercase letter.
912 s/l/r/ Substitute l for r. l is simply a string like r, not a
913 regular expression as in the eponymous ed(1) command. Any
914 character may be used as the delimiter in place of `/'; a
915 `\' can be used to quote the delimiter inside l and r. The
916 character `&' in the r is replaced by l; `\' also quotes
917 `&'. If l is empty (``''), the l from a previous substitu‐
918 tion or the s from a previous search or event number in
919 event specification is used. The trailing delimiter may be
920 omitted if it is immediately followed by a newline.
921 & Repeat the previous substitution.
922 g Apply the following modifier once to each word.
923 a (+) Apply the following modifier as many times as possible to a
924 single word. `a' and `g' can be used together to apply a
925 modifier globally. With the `s' modifier, only the pat‐
926 terns contained in the original word are substituted, not
927 patterns that contain any substitution result.
928 p Print the new command line but do not execute it.
929 q Quote the substituted words, preventing further substitu‐
930 tions.
931 x Like q, but break into words at blanks, tabs and newlines.
932 Modifiers are applied to only the first modifiable word (unless `g' is
934 used). It is an error for no word to be modifiable.
935 For example, the `diff' command might have been written as `diff wum‐
937 pus.man.old !#^:r', using `:r' to remove `.old' from the first argument
938 on the same line (`!#^'). We could say `echo hello out there', then
939 `echo !*:u' to capitalize `hello', `echo !*:au' to say it out loud, or
940 `echo !*:agu' to really shout. We might follow `mail -s "I forgot my
941 password" rot' with `!:s/rot/root' to correct the spelling of `root'
942 (but see Spelling correction for a different approach).
943 There is a special abbreviation for substitutions. `^', when it is the
945 first character on an input line, is equivalent to `!:s^'. Thus we
946 might have said `^rot^root' to make the spelling correction in the pre‐
947 vious example. This is the only history substitution which does not
948 explicitly begin with `!'.
949 (+) In csh as such, only one modifier may be applied to each history or
951 variable expansion. In tcsh, more than one may be used, for example
952 % mv wumpus.man /usr/man/man1/wumpus.1
954 % man !$:t:r
955 man wumpus
956 In csh, the result would be `wumpus.1:r'. A substitution followed by a
958 colon may need to be insulated from it with braces:
959 > mv a.out /usr/games/wumpus
961 > setenv PATH !$:h:$PATH
962 Bad ! modifier: $.
963 > setenv PATH !{-2$:h}:$PATH
964 setenv PATH /usr/games:/bin:/usr/bin:.
965 The first attempt would succeed in csh but fails in tcsh, because tcsh
967 expects another modifier after the second colon rather than `$'.
968 Finally, history can be accessed through the editor as well as through
970 the substitutions just described. The up- and down-history, history-
971 search-backward and -forward, i-search-back and -fwd, vi-search-back
972 and -fwd, copy-prev-word and insert-last-word editor commands search
973 for events in the history list and copy them into the input buffer.
974 The toggle-literal-history editor command switches between the expanded
975 and literal forms of history lines in the input buffer. expand-history
976 and expand-line expand history substitutions in the current word and in
977 the entire input buffer respectively.
978 Alias substitution
980 The shell maintains a list of aliases which can be set, unset and
981 printed by the alias and unalias commands. After a command line is
982 parsed into simple commands (see Commands) the first word of each com‐
983 mand, left-to-right, is checked to see if it has an alias. If so, the
984 first word is replaced by the alias. If the alias contains a history
985 reference, it undergoes History substitution (q.v.) as though the orig‐
986 inal command were the previous input line. If the alias does not con‐
987 tain a history reference, the argument list is left untouched.
988 Thus if the alias for `ls' were `ls -l' the command `ls /usr' would
990 become `ls -l /usr', the argument list here being undisturbed. If the
991 alias for `lookup' were `grep !^ /etc/passwd' then `lookup bill' would
992 become `grep bill /etc/passwd'. Aliases can be used to introduce
993 parser metasyntax. For example, `alias print 'pr \!* | lpr'' defines a
994 ``command'' (`print') which pr(1)s its arguments to the line printer.
995 Alias substitution is repeated until the first word of the command has
997 no alias. If an alias substitution does not change the first word (as
998 in the previous example) it is flagged to prevent a loop. Other loops
999 are detected and cause an error.
1000 Some aliases are referred to by the shell; see Special aliases.
1002 Variable substitution
1004 The shell maintains a list of variables, each of which has as value a
1005 list of zero or more words. The values of shell variables can be dis‐
1006 played and changed with the set and unset commands. The system main‐
1007 tains its own list of ``environment'' variables. These can be dis‐
1008 played and changed with printenv, setenv and unsetenv.
1009 (+) Variables may be made read-only with `set -r' (q.v.). Read-only
1011 variables may not be modified or unset; attempting to do so will cause
1012 an error. Once made read-only, a variable cannot be made writable, so
1013 `set -r' should be used with caution. Environment variables cannot be
1014 made read-only.
1015 Some variables are set by the shell or referred to by it. For
1017 instance, the argv variable is an image of the shell's argument list,
1018 and words of this variable's value are referred to in special ways.
1019 Some of the variables referred to by the shell are toggles; the shell
1020 does not care what their value is, only whether they are set or not.
1021 For instance, the verbose variable is a toggle which causes command
1022 input to be echoed. The -v command line option sets this variable.
1023 Special shell variables lists all variables which are referred to by
1024 the shell.
1025 Other operations treat variables numerically. The `@' command permits
1027 numeric calculations to be performed and the result assigned to a vari‐
1028 able. Variable values are, however, always represented as (zero or
1029 more) strings. For the purposes of numeric operations, the null string
1030 is considered to be zero, and the second and subsequent words of multi-
1031 word values are ignored.
1032 After the input line is aliased and parsed, and before each command is
1034 executed, variable substitution is performed keyed by `$' characters.
1035 This expansion can be prevented by preceding the `$' with a `\' except
1036 within `"'s where it always occurs, and within `''s where it never
1037 occurs. Strings quoted by ``' are interpreted later (see Command sub‐
1038 stitution below) so `$' substitution does not occur there until later,
1039 if at all. A `$' is passed unchanged if followed by a blank, tab, or
1040 end-of-line.
1041 Input/output redirections are recognized before variable expansion, and
1043 are variable expanded separately. Otherwise, the command name and
1044 entire argument list are expanded together. It is thus possible for
1045 the first (command) word (to this point) to generate more than one
1046 word, the first of which becomes the command name, and the rest of
1047 which become arguments.
1048 Unless enclosed in `"' or given the `:q' modifier the results of vari‐
1050 able substitution may eventually be command and filename substituted.
1051 Within `"', a variable whose value consists of multiple words expands
1052 to a (portion of a) single word, with the words of the variable's value
1053 separated by blanks. When the `:q' modifier is applied to a substitu‐
1054 tion the variable will expand to multiple words with each word sepa‐
1055 rated by a blank and quoted to prevent later command or filename sub‐
1056 stitution.
1057 The following metasequences are provided for introducing variable val‐
1059 ues into the shell input. Except as noted, it is an error to reference
1060 a variable which is not set.
1061 $name
1063 ${name} Substitutes the words of the value of variable name, each sepa‐
1064 rated by a blank. Braces insulate name from following charac‐
1065 ters which would otherwise be part of it. Shell variables have
1066 names consisting of letters and digits starting with a letter.
1067 The underscore character is considered a letter. If name is
1068 not a shell variable, but is set in the environment, then that
1069 value is returned (but some of the other forms given below are
1070 not available in this case).
1071 $name[selector]
1072 ${name[selector]}
1073 Substitutes only the selected words from the value of name.
1074 The selector is subjected to `$' substitution and may consist
1075 of a single number or two numbers separated by a `-'. The
1076 first word of a variable's value is numbered `1'. If the first
1077 number of a range is omitted it defaults to `1'. If the last
1078 member of a range is omitted it defaults to `$#name'. The
1079 selector `*' selects all words. It is not an error for a range
1080 to be empty if the second argument is omitted or in range.
1081 $0 Substitutes the name of the file from which command input is
1082 being read. An error occurs if the name is not known.
1083 $number
1084 ${number}
1085 Equivalent to `$argv[number]'.
1086 $* Equivalent to `$argv', which is equivalent to `$argv[*]'.
1087 The `:' modifiers described under History substitution, except for
1089 `:p', can be applied to the substitutions above. More than one may be
1090 used. (+) Braces may be needed to insulate a variable substitution
1091 from a literal colon just as with History substitution (q.v.); any mod‐
1092 ifiers must appear within the braces.
1093 The following substitutions can not be modified with `:' modifiers.
1095 $?name
1097 ${?name}
1098 Substitutes the string `1' if name is set, `0' if it is not.
1099 $?0 Substitutes `1' if the current input filename is known, `0' if
1100 it is not. Always `0' in interactive shells.
1101 $#name
1102 ${#name}
1103 Substitutes the number of words in name.
1104 $# Equivalent to `$#argv'. (+)
1105 $%name
1106 ${%name}
1107 Substitutes the number of characters in name. (+)
1108 $%number
1109 ${%number}
1110 Substitutes the number of characters in $argv[number]. (+)
1111 $? Equivalent to `$status'. (+)
1112 $$ Substitutes the (decimal) process number of the (parent) shell.
1113 $! Substitutes the (decimal) process number of the last background
1114 process started by this shell. (+)
1115 $_ Substitutes the command line of the last command executed. (+)
1116 $< Substitutes a line from the standard input, with no further
1117 interpretation thereafter. It can be used to read from the
1118 keyboard in a shell script. (+) While csh always quotes $<, as
1119 if it were equivalent to `$<:q', tcsh does not. Furthermore,
1120 when tcsh is waiting for a line to be typed the user may type
1121 an interrupt to interrupt the sequence into which the line is
1122 to be substituted, but csh does not allow this.
1123 The editor command expand-variables, normally bound to `^X-$', can be
1125 used to interactively expand individual variables.
1126 Command, filename and directory stack substitution
1128 The remaining substitutions are applied selectively to the arguments of
1129 builtin commands. This means that portions of expressions which are
1130 not evaluated are not subjected to these expansions. For commands
1131 which are not internal to the shell, the command name is substituted
1132 separately from the argument list. This occurs very late, after input-
1133 output redirection is performed, and in a child of the main shell.
1134 Command substitution
1136 Command substitution is indicated by a command enclosed in ``'. The
1137 output from such a command is broken into separate words at blanks,
1138 tabs and newlines, and null words are discarded. The output is vari‐
1139 able and command substituted and put in place of the original string.
1140 Command substitutions inside double quotes (`"') retain blanks and
1142 tabs; only newlines force new words. The single final newline does not
1143 force a new word in any case. It is thus possible for a command sub‐
1144 stitution to yield only part of a word, even if the command outputs a
1145 complete line.
1146 By default, the shell since version 6.12 replaces all newline and car‐
1148 riage return characters in the command by spaces. If this is switched
1149 off by unsetting csubstnonl, newlines separate commands as usual.
1150 Filename substitution
1152 If a word contains any of the characters `*', `?', `[' or `{' or begins
1153 with the character `~' it is a candidate for filename substitution,
1154 also known as ``globbing''. This word is then regarded as a pattern
1155 (``glob-pattern''), and replaced with an alphabetically sorted list of
1156 file names which match the pattern.
1157 In matching filenames, the character `.' at the beginning of a filename
1159 or immediately following a `/', as well as the character `/' must be
1160 matched explicitly (unless either globdot or globstar or both are
1161 set(+)). The character `*' matches any string of characters, including
1162 the null string. The character `?' matches any single character. The
1163 sequence `[...]' matches any one of the characters enclosed. Within
1164 `[...]', a pair of characters separated by `-' matches any character
1165 lexically between the two.
1166 (+) Some glob-patterns can be negated: The sequence `[^...]' matches
1168 any single character not specified by the characters and/or ranges of
1169 characters in the braces.
1170 An entire glob-pattern can also be negated with `^':
1172 > echo *
1174 bang crash crunch ouch
1175 > echo ^cr*
1176 bang ouch
1177 Glob-patterns which do not use `?', `*', or `[]' or which use `{}' or
1179 `~' (below) are not negated correctly.
1180 The metanotation `a{b,c,d}e' is a shorthand for `abe ace ade'. Left-
1182 to-right order is preserved: `/usr/source/s1/{oldls,ls}.c' expands to
1183 `/usr/source/s1/oldls.c /usr/source/s1/ls.c'. The results of matches
1184 are sorted separately at a low level to preserve this order:
1185 `../{memo,*box}' might expand to `../memo ../box ../mbox'. (Note that
1186 `memo' was not sorted with the results of matching `*box'.) It is not
1187 an error when this construct expands to files which do not exist, but
1188 it is possible to get an error from a command to which the expanded
1189 list is passed. This construct may be nested. As a special case the
1190 words `{', `}' and `{}' are passed undisturbed.
1191 The character `~' at the beginning of a filename refers to home direc‐
1193 tories. Standing alone, i.e., `~', it expands to the invoker's home
1194 directory as reflected in the value of the home shell variable. When
1195 followed by a name consisting of letters, digits and `-' characters the
1196 shell searches for a user with that name and substitutes their home
1197 directory; thus `~ken' might expand to `/usr/ken' and `~ken/chmach' to
1198 `/usr/ken/chmach'. If the character `~' is followed by a character
1199 other than a letter or `/' or appears elsewhere than at the beginning
1200 of a word, it is left undisturbed. A command like `setenv MANPATH
1201 /usr/man:/usr/local/man:~/lib/man' does not, therefore, do home direc‐
1202 tory substitution as one might hope.
1203 It is an error for a glob-pattern containing `*', `?', `[' or `~', with
1205 or without `^', not to match any files. However, only one pattern in a
1206 list of glob-patterns must match a file (so that, e.g., `rm *.a *.c
1207 *.o' would fail only if there were no files in the current directory
1208 ending in `.a', `.c', or `.o'), and if the nonomatch shell variable is
1209 set a pattern (or list of patterns) which matches nothing is left
1210 unchanged rather than causing an error.
1211 The globstar shell variable can be set to allow `**' or `***' as a file
1213 glob pattern that matches any string of characters including `/',
1214 recursively traversing any existing sub-directories. For example, `ls
1215 **.c' will list all the .c files in the current directory tree. If
1216 used by itself, it will match zero or more sub-directories (e.g. `ls
1217 /usr/include/**/time.h' will list any file named `time.h' in the
1218 /usr/include directory tree; `ls /usr/include/**time.h' will match any
1219 file in the /usr/include directory tree ending in `time.h'; and `ls
1220 /usr/include/**time**.h' will match any .h file with `time' either in a
1221 subdirectory name or in the filename itself). To prevent problems with
1222 recursion, the `**' glob-pattern will not descend into a symbolic link
1223 containing a directory. To override this, use `***' (+)
1224 The noglob shell variable can be set to prevent filename substitution,
1226 and the expand-glob editor command, normally bound to `^X-*', can be
1227 used to interactively expand individual filename substitutions.
1228 Directory stack substitution (+)
1230 The directory stack is a list of directories, numbered from zero, used
1231 by the pushd, popd and dirs builtin commands (q.v.). dirs can print,
1232 store in a file, restore and clear the directory stack at any time, and
1233 the savedirs and dirsfile shell variables can be set to store the
1234 directory stack automatically on logout and restore it on login. The
1235 dirstack shell variable can be examined to see the directory stack and
1236 set to put arbitrary directories into the directory stack.
1237 The character `=' followed by one or more digits expands to an entry in
1239 the directory stack. The special case `=-' expands to the last direc‐
1240 tory in the stack. For example,
1241 > dirs -v
1243 0 /usr/bin
1244 1 /usr/spool/uucp
1245 2 /usr/accts/sys
1246 > echo =1
1247 /usr/spool/uucp
1248 > echo =0/calendar
1249 /usr/bin/calendar
1250 > echo =-
1251 /usr/accts/sys
1252 The noglob and nonomatch shell variables and the expand-glob editor
1254 command apply to directory stack as well as filename substitutions.
1255 Other substitutions (+)
1257 There are several more transformations involving filenames, not
1258 strictly related to the above but mentioned here for completeness. Any
1259 filename may be expanded to a full path when the symlinks variable
1260 (q.v.) is set to `expand'. Quoting prevents this expansion, and the
1261 normalize-path editor command does it on demand. The normalize-command
1262 editor command expands commands in PATH into full paths on demand.
1263 Finally, cd and pushd interpret `-' as the old working directory
1264 (equivalent to the shell variable owd). This is not a substitution at
1265 all, but an abbreviation recognized by only those commands. Nonethe‐
1266 less, it too can be prevented by quoting.
1267 Commands
1269 The next three sections describe how the shell executes commands and
1270 deals with their input and output.
1271 Simple commands, pipelines and sequences
1273 A simple command is a sequence of words, the first of which specifies
1274 the command to be executed. A series of simple commands joined by `|'
1275 characters forms a pipeline. The output of each command in a pipeline
1276 is connected to the input of the next.
1277 Simple commands and pipelines may be joined into sequences with `;',
1279 and will be executed sequentially. Commands and pipelines can also be
1280 joined into sequences with `||' or `&&', indicating, as in the C lan‐
1281 guage, that the second is to be executed only if the first fails or
1282 succeeds respectively.
1283 A simple command, pipeline or sequence may be placed in parentheses,
1285 `()', to form a simple command, which may in turn be a component of a
1286 pipeline or sequence. A command, pipeline or sequence can be executed
1287 without waiting for it to terminate by following it with an `&'.
1288 Builtin and non-builtin command execution
1290 Builtin commands are executed within the shell. If any component of a
1291 pipeline except the last is a builtin command, the pipeline is executed
1292 in a subshell.
1293 Parenthesized commands are always executed in a subshell.
1295 (cd; pwd); pwd
1297 thus prints the home directory, leaving you where you were (printing
1299 this after the home directory), while
1300 cd; pwd
1302 leaves you in the home directory. Parenthesized commands are most
1304 often used to prevent cd from affecting the current shell.
1305 When a command to be executed is found not to be a builtin command the
1307 shell attempts to execute the command via execve(2). Each word in the
1308 variable path names a directory in which the shell will look for the
1309 command. If the shell is not given a -f option, the shell hashes the
1310 names in these directories into an internal table so that it will try
1311 an execve(2) in only a directory where there is a possibility that the
1312 command resides there. This greatly speeds command location when a
1313 large number of directories are present in the search path. This hash‐
1314 ing mechanism is not used:
1315 1. If hashing is turned explicitly off via unhash.
1317 2. If the shell was given a -f argument.
1319 3. For each directory component of path which does not begin with a
1321 `/'.
1322 4. If the command contains a `/'.
1324 In the above four cases the shell concatenates each component of the
1326 path vector with the given command name to form a path name of a file
1327 which it then attempts to execute it. If execution is successful, the
1328 search stops.
1329 If the file has execute permissions but is not an executable to the
1331 system (i.e., it is neither an executable binary nor a script that
1332 specifies its interpreter), then it is assumed to be a file containing
1333 shell commands and a new shell is spawned to read it. The shell spe‐
1334 cial alias may be set to specify an interpreter other than the shell
1335 itself.
1336 On systems which do not understand the `#!' script interpreter conven‐
1338 tion the shell may be compiled to emulate it; see the version shell
1339 variable. If so, the shell checks the first line of the file to see if
1340 it is of the form `#!interpreter arg ...'. If it is, the shell starts
1341 interpreter with the given args and feeds the file to it on standard
1342 input.
1343 Input/output
1345 The standard input and standard output of a command may be redirected
1346 with the following syntax:
1347 < name Open file name (which is first variable, command and filename
1349 expanded) as the standard input.
1350 << word Read the shell input up to a line which is identical to word.
1351 word is not subjected to variable, filename or command substi‐
1352 tution, and each input line is compared to word before any sub‐
1353 stitutions are done on this input line. Unless a quoting `\',
1354 `"', `' or ``' appears in word variable and command substitu‐
1355 tion is performed on the intervening lines, allowing `\' to
1356 quote `$', `\' and ``'. Commands which are substituted have
1357 all blanks, tabs, and newlines preserved, except for the final
1358 newline which is dropped. The resultant text is placed in an
1359 anonymous temporary file which is given to the command as stan‐
1360 dard input.
1361 > name
1362 >! name
1363 >& name
1364 >&! name
1365 The file name is used as standard output. If the file does not
1366 exist then it is created; if the file exists, it is truncated,
1367 its previous contents being lost.
1368 If the shell variable noclobber is set, then the file must not
1370 exist or be a character special file (e.g., a terminal or
1371 `/dev/null') or an error results. This helps prevent acciden‐
1372 tal destruction of files. In this case the `!' forms can be
1373 used to suppress this check. If notempty is given in noclob‐
1374 ber, `>' is allowed on empty files; if ask is set, an
1375 interacive confirmation is presented, rather than an error.
1376 The forms involving `&' route the diagnostic output into the
1378 specified file as well as the standard output. name is
1379 expanded in the same way as `<' input filenames are.
1380 >> name
1381 >>& name
1382 >>! name
1383 >>&! name
1384 Like `>', but appends output to the end of name. If the shell
1385 variable noclobber is set, then it is an error for the file not
1386 to exist, unless one of the `!' forms is given.
1387 A command receives the environment in which the shell was invoked as
1389 modified by the input-output parameters and the presence of the command
1390 in a pipeline. Thus, unlike some previous shells, commands run from a
1391 file of shell commands have no access to the text of the commands by
1392 default; rather they receive the original standard input of the shell.
1393 The `<<' mechanism should be used to present inline data. This permits
1394 shell command scripts to function as components of pipelines and allows
1395 the shell to block read its input. Note that the default standard
1396 input for a command run detached is not the empty file /dev/null, but
1397 the original standard input of the shell. If this is a terminal and if
1398 the process attempts to read from the terminal, then the process will
1399 block and the user will be notified (see Jobs).
1400 Diagnostic output may be directed through a pipe with the standard out‐
1402 put. Simply use the form `|&' rather than just `|'.
1403 The shell cannot presently redirect diagnostic output without also
1405 redirecting standard output, but `(command > output-file) >& error-
1406 file' is often an acceptable workaround. Either output-file or error-
1407 file may be `/dev/tty' to send output to the terminal.
1408 Features
1410 Having described how the shell accepts, parses and executes command
1411 lines, we now turn to a variety of its useful features.
1412 Control flow
1414 The shell contains a number of commands which can be used to regulate
1415 the flow of control in command files (shell scripts) and (in limited
1416 but useful ways) from terminal input. These commands all operate by
1417 forcing the shell to reread or skip in its input and, due to the imple‐
1418 mentation, restrict the placement of some of the commands.
1419 The foreach, switch, and while statements, as well as the if-then-else
1421 form of the if statement, require that the major keywords appear in a
1422 single simple command on an input line as shown below.
1423 If the shell's input is not seekable, the shell buffers up input when‐
1425 ever a loop is being read and performs seeks in this internal buffer to
1426 accomplish the rereading implied by the loop. (To the extent that this
1427 allows, backward gotos will succeed on non-seekable inputs.)
1428 Expressions
1430 The if, while and exit builtin commands use expressions with a common
1431 syntax. The expressions can include any of the operators described in
1432 the next three sections. Note that the @ builtin command (q.v.) has
1433 its own separate syntax.
1434 Logical, arithmetical and comparison operators
1436 These operators are similar to those of C and have the same precedence.
1437 They include
1438 || && | ^ & == != =~ !~ <= >=
1440 < > << >> + - * / % ! ~ ( )
1441 Here the precedence increases to the right, `==' `!=' `=~' and `!~',
1443 `<=' `>=' `<' and `>', `<<' and `>>', `+' and `-', `*' `/' and `%'
1444 being, in groups, at the same level. The `==' `!=' `=~' and `!~' oper‐
1445 ators compare their arguments as strings; all others operate on num‐
1446 bers. The operators `=~' and `!~' are like `!=' and `==' except that
1447 the right hand side is a glob-pattern (see Filename substitution)
1448 against which the left hand operand is matched. This reduces the need
1449 for use of the switch builtin command in shell scripts when all that is
1450 really needed is pattern matching.
1451 Null or missing arguments are considered `0'. The results of all
1453 expressions are strings, which represent decimal numbers. It is impor‐
1454 tant to note that no two components of an expression can appear in the
1455 same word; except when adjacent to components of expressions which are
1456 syntactically significant to the parser (`&' `|' `<' `>' `(' `)') they
1457 should be surrounded by spaces.
1458 Command exit status
1460 Commands can be executed in expressions and their exit status returned
1461 by enclosing them in braces (`{}'). Remember that the braces should be
1462 separated from the words of the command by spaces. Command executions
1463 succeed, returning true, i.e., `1', if the command exits with status 0,
1464 otherwise they fail, returning false, i.e., `0'. If more detailed sta‐
1465 tus information is required then the command should be executed outside
1466 of an expression and the status shell variable examined.
1467 File inquiry operators
1469 Some of these operators perform true/false tests on files and related
1470 objects. They are of the form -op file, where op is one of
1471 r Read access
1473 w Write access
1474 x Execute access
1475 X Executable in the path or shell builtin, e.g., `-X ls' and `-X
1476 ls-F' are generally true, but `-X /bin/ls' is not (+)
1477 e Existence
1478 o Ownership
1479 z Zero size
1480 s Non-zero size (+)
1481 f Plain file
1482 d Directory
1483 l Symbolic link (+) *
1484 b Block special file (+)
1485 c Character special file (+)
1486 p Named pipe (fifo) (+) *
1487 S Socket special file (+) *
1488 u Set-user-ID bit is set (+)
1489 g Set-group-ID bit is set (+)
1490 k Sticky bit is set (+)
1491 t file (which must be a digit) is an open file descriptor for a
1492 terminal device (+)
1493 R Has been migrated (Convex only) (+)
1494 L Applies subsequent operators in a multiple-operator test to a
1495 symbolic link rather than to the file to which the link points
1496 (+) *
1497 file is command and filename expanded and then tested to see if it has
1499 the specified relationship to the real user. If file does not exist or
1500 is inaccessible or, for the operators indicated by `*', if the speci‐
1501 fied file type does not exist on the current system, then all inquiries
1502 return false, i.e., `0'.
1503 These operators may be combined for conciseness: `-xy file' is equiva‐
1505 lent to `-x file && -y file'. (+) For example, `-fx' is true (returns
1506 `1') for plain executable files, but not for directories.
1507 L may be used in a multiple-operator test to apply subsequent operators
1509 to a symbolic link rather than to the file to which the link points.
1510 For example, `-lLo' is true for links owned by the invoking user. Lr,
1511 Lw and Lx are always true for links and false for non-links. L has a
1512 different meaning when it is the last operator in a multiple-operator
1513 test; see below.
1514 It is possible but not useful, and sometimes misleading, to combine
1516 operators which expect file to be a file with operators which do not
1517 (e.g., X and t). Following L with a non-file operator can lead to par‐
1518 ticularly strange results.
1519 Other operators return other information, i.e., not just `0' or `1'.
1521 (+) They have the same format as before; op may be one of
1522 A Last file access time, as the number of seconds since the
1524 epoch
1525 A: Like A, but in timestamp format, e.g., `Fri May 14 16:36:10
1526 1993'
1527 M Last file modification time
1528 M: Like M, but in timestamp format
1529 C Last inode modification time
1530 C: Like C, but in timestamp format
1531 D Device number
1532 I Inode number
1533 F Composite file identifier, in the form device:inode
1534 L The name of the file pointed to by a symbolic link
1535 N Number of (hard) links
1536 P Permissions, in octal, without leading zero
1537 P: Like P, with leading zero
1538 Pmode Equivalent to `-P file & mode', e.g., `-P22 file' returns
1539 `22' if file is writable by group and other, `20' if by
1540 group only, and `0' if by neither
1541 Pmode: Like Pmode, with leading zero
1542 U Numeric userid
1543 U: Username, or the numeric userid if the username is unknown
1544 G Numeric groupid
1545 G: Groupname, or the numeric groupid if the groupname is
1546 unknown
1547 Z Size, in bytes
1548 Only one of these operators may appear in a multiple-operator test, and
1550 it must be the last. Note that L has a different meaning at the end of
1551 and elsewhere in a multiple-operator test. Because `0' is a valid
1552 return value for many of these operators, they do not return `0' when
1553 they fail: most return `-1', and F returns `:'.
1554 If the shell is compiled with POSIX defined (see the version shell
1556 variable), the result of a file inquiry is based on the permission bits
1557 of the file and not on the result of the access(2) system call. For
1558 example, if one tests a file with -w whose permissions would ordinarily
1559 allow writing but which is on a file system mounted read-only, the test
1560 will succeed in a POSIX shell but fail in a non-POSIX shell.
1561 File inquiry operators can also be evaluated with the filetest builtin
1563 command (q.v.) (+).
1564 Jobs
1566 The shell associates a job with each pipeline. It keeps a table of
1567 current jobs, printed by the jobs command, and assigns them small inte‐
1568 ger numbers. When a job is started asynchronously with `&', the shell
1569 prints a line which looks like
1570 [1] 1234
1572 indicating that the job which was started asynchronously was job number
1574 1 and had one (top-level) process, whose process id was 1234.
1575 If you are running a job and wish to do something else you may hit the
1577 suspend key (usually `^Z'), which sends a STOP signal to the current
1578 job. The shell will then normally indicate that the job has been `Sus‐
1579 pended' and print another prompt. If the listjobs shell variable is
1580 set, all jobs will be listed like the jobs builtin command; if it is
1581 set to `long' the listing will be in long format, like `jobs -l'. You
1582 can then manipulate the state of the suspended job. You can put it in
1583 the ``background'' with the bg command or run some other commands and
1584 eventually bring the job back into the ``foreground'' with fg. (See
1585 also the run-fg-editor editor command.) A `^Z' takes effect immedi‐
1586 ately and is like an interrupt in that pending output and unread input
1587 are discarded when it is typed. The wait builtin command causes the
1588 shell to wait for all background jobs to complete.
1589 The `^]' key sends a delayed suspend signal, which does not generate a
1591 STOP signal until a program attempts to read(2) it, to the current job.
1592 This can usefully be typed ahead when you have prepared some commands
1593 for a job which you wish to stop after it has read them. The `^Y' key
1594 performs this function in csh(1); in tcsh, `^Y' is an editing command.
1595 (+)
1596 A job being run in the background stops if it tries to read from the
1598 terminal. Background jobs are normally allowed to produce output, but
1599 this can be disabled by giving the command `stty tostop'. If you set
1600 this tty option, then background jobs will stop when they try to pro‐
1601 duce output like they do when they try to read input.
1602 There are several ways to refer to jobs in the shell. The character
1604 `%' introduces a job name. If you wish to refer to job number 1, you
1605 can name it as `%1'. Just naming a job brings it to the foreground;
1606 thus `%1' is a synonym for `fg %1', bringing job 1 back into the fore‐
1607 ground. Similarly, saying `%1 &' resumes job 1 in the background, just
1608 like `bg %1'. A job can also be named by an unambiguous prefix of the
1609 string typed in to start it: `%ex' would normally restart a suspended
1610 ex(1) job, if there were only one suspended job whose name began with
1611 the string `ex'. It is also possible to say `%?string' to specify a
1612 job whose text contains string, if there is only one such job.
1613 The shell maintains a notion of the current and previous jobs. In out‐
1615 put pertaining to jobs, the current job is marked with a `+' and the
1616 previous job with a `-'. The abbreviations `%+', `%', and (by analogy
1617 with the syntax of the history mechanism) `%%' all refer to the current
1618 job, and `%-' refers to the previous job.
1619 The job control mechanism requires that the stty(1) option `new' be set
1621 on some systems. It is an artifact from a `new' implementation of the
1622 tty driver which allows generation of interrupt characters from the
1623 keyboard to tell jobs to stop. See stty(1) and the setty builtin com‐
1624 mand for details on setting options in the new tty driver.
1625 Status reporting
1627 The shell learns immediately whenever a process changes state. It nor‐
1628 mally informs you whenever a job becomes blocked so that no further
1629 progress is possible, but only right before it prints a prompt. This
1630 is done so that it does not otherwise disturb your work. If, however,
1631 you set the shell variable notify, the shell will notify you immedi‐
1632 ately of changes of status in background jobs. There is also a shell
1633 command notify which marks a single process so that its status changes
1634 will be immediately reported. By default notify marks the current
1635 process; simply say `notify' after starting a background job to mark
1636 it.
1637 When you try to leave the shell while jobs are stopped, you will be
1639 warned that `There are suspended jobs.' You may use the jobs command to
1640 see what they are. If you do this or immediately try to exit again,
1641 the shell will not warn you a second time, and the suspended jobs will
1642 be terminated.
1643 Automatic, periodic and timed events (+)
1645 There are various ways to run commands and take other actions automati‐
1646 cally at various times in the ``life cycle'' of the shell. They are
1647 summarized here, and described in detail under the appropriate Builtin
1648 commands, Special shell variables and Special aliases.
1649 The sched builtin command puts commands in a scheduled-event list, to
1651 be executed by the shell at a given time.
1652 The beepcmd, cwdcmd, periodic, precmd, postcmd, and jobcmd Special
1654 aliases can be set, respectively, to execute commands when the shell
1655 wants to ring the bell, when the working directory changes, every tpe‐
1656 riod minutes, before each prompt, before each command gets executed,
1657 after each command gets executed, and when a job is started or is
1658 brought into the foreground.
1659 The autologout shell variable can be set to log out or lock the shell
1661 after a given number of minutes of inactivity.
1662 The mail shell variable can be set to check for new mail periodically.
1664 The printexitvalue shell variable can be set to print the exit status
1666 of commands which exit with a status other than zero.
1667 The rmstar shell variable can be set to ask the user, when `rm *' is
1669 typed, if that is really what was meant.
1670 The time shell variable can be set to execute the time builtin command
1672 after the completion of any process that takes more than a given number
1673 of CPU seconds.
1674 The watch and who shell variables can be set to report when selected
1676 users log in or out, and the log builtin command reports on those users
1677 at any time.
1678 Native Language System support (+)
1680 The shell is eight bit clean (if so compiled; see the version shell
1681 variable) and thus supports character sets needing this capability.
1682 NLS support differs depending on whether or not the shell was compiled
1683 to use the system's NLS (again, see version). In either case, 7-bit
1684 ASCII is the default character code (e.g., the classification of which
1685 characters are printable) and sorting, and changing the LANG or
1686 LC_CTYPE environment variables causes a check for possible changes in
1687 these respects.
1688 When using the system's NLS, the setlocale(3) function is called to
1690 determine appropriate character code/classification and sorting (e.g.,
1691 a 'en_CA.UTF-8' would yield "UTF-8" as a character code). This func‐
1692 tion typically examines the LANG and LC_CTYPE environment variables;
1693 refer to the system documentation for further details. When not using
1694 the system's NLS, the shell simulates it by assuming that the ISO
1695 8859-1 character set is used whenever either of the LANG and LC_CTYPE
1696 variables are set, regardless of their values. Sorting is not affected
1697 for the simulated NLS.
1698 In addition, with both real and simulated NLS, all printable characters
1700 in the range \200-\377, i.e., those that have M-char bindings, are
1701 automatically rebound to self-insert-command. The corresponding bind‐
1702 ing for the escape-char sequence, if any, is left alone. These charac‐
1703 ters are not rebound if the NOREBIND environment variable is set. This
1704 may be useful for the simulated NLS or a primitive real NLS which
1705 assumes full ISO 8859-1. Otherwise, all M-char bindings in the range
1706 \240-\377 are effectively undone. Explicitly rebinding the relevant
1707 keys with bindkey is of course still possible.
1708 Unknown characters (i.e., those that are neither printable nor control
1710 characters) are printed in the format \nnn. If the tty is not in 8 bit
1711 mode, other 8 bit characters are printed by converting them to ASCII
1712 and using standout mode. The shell never changes the 7/8 bit mode of
1713 the tty and tracks user-initiated changes of 7/8 bit mode. NLS users
1714 (or, for that matter, those who want to use a meta key) may need to
1715 explicitly set the tty in 8 bit mode through the appropriate stty(1)
1716 command in, e.g., the ~/.login file.
1717 OS variant support (+)
1719 A number of new builtin commands are provided to support features in
1720 particular operating systems. All are described in detail in the
1721 Builtin commands section.
1722 On systems that support TCF (aix-ibm370, aix-ps2), getspath and
1724 setspath get and set the system execution path, getxvers and setxvers
1725 get and set the experimental version prefix and migrate migrates pro‐
1726 cesses between sites. The jobs builtin prints the site on which each
1727 job is executing.
1728 Under BS2000, bs2cmd executes commands of the underlying BS2000/OSD
1730 operating system.
1731 Under Domain/OS, inlib adds shared libraries to the current environ‐
1733 ment, rootnode changes the rootnode and ver changes the systype.
1734 Under Mach, setpath is equivalent to Mach's setpath(1).
1736 Under Masscomp/RTU and Harris CX/UX, universe sets the universe.
1738 Under Harris CX/UX, ucb or att runs a command under the specified uni‐
1740 verse.
1741 Under Convex/OS, warp prints or sets the universe.
1743 The VENDOR, OSTYPE and MACHTYPE environment variables indicate respec‐
1745 tively the vendor, operating system and machine type (microprocessor
1746 class or machine model) of the system on which the shell thinks it is
1747 running. These are particularly useful when sharing one's home direc‐
1748 tory between several types of machines; one can, for example,
1749 set path = (~/bin.$MACHTYPE /usr/ucb /bin /usr/bin .)
1751 in one's ~/.login and put executables compiled for each machine in the
1753 appropriate directory.
1754 The version shell variable indicates what options were chosen when the
1756 shell was compiled.
1757 Note also the newgrp builtin, the afsuser and echo_style shell vari‐
1759 ables and the system-dependent locations of the shell's input files
1760 (see FILES).
1761 Signal handling
1763 Login shells ignore interrupts when reading the file ~/.logout. The
1764 shell ignores quit signals unless started with -q. Login shells catch
1765 the terminate signal, but non-login shells inherit the terminate behav‐
1766 ior from their parents. Other signals have the values which the shell
1767 inherited from its parent.
1768 In shell scripts, the shell's handling of interrupt and terminate sig‐
1770 nals can be controlled with onintr, and its handling of hangups can be
1771 controlled with hup and nohup.
1772 The shell exits on a hangup (see also the logout shell variable). By
1774 default, the shell's children do too, but the shell does not send them
1775 a hangup when it exits. hup arranges for the shell to send a hangup to
1776 a child when it exits, and nohup sets a child to ignore hangups.
1777 Terminal management (+)
1779 The shell uses three different sets of terminal (``tty'') modes:
1780 `edit', used when editing, `quote', used when quoting literal charac‐
1781 ters, and `execute', used when executing commands. The shell holds
1782 some settings in each mode constant, so commands which leave the tty in
1783 a confused state do not interfere with the shell. The shell also
1784 matches changes in the speed and padding of the tty. The list of tty
1785 modes that are kept constant can be examined and modified with the
1786 setty builtin. Note that although the editor uses CBREAK mode (or its
1787 equivalent), it takes typed-ahead characters anyway.
1788 The echotc, settc and telltc commands can be used to manipulate and
1790 debug terminal capabilities from the command line.
1791 On systems that support SIGWINCH or SIGWINDOW, the shell adapts to win‐
1793 dow resizing automatically and adjusts the environment variables LINES
1794 and COLUMNS if set. If the environment variable TERMCAP contains li#
1795 and co# fields, the shell adjusts them to reflect the new window size.
1796
1798 The next sections of this manual describe all of the available Builtin
1799 commands, Special aliases and Special shell variables.
1800 Builtin commands
1802 %job A synonym for the fg builtin command.
1803 %job & A synonym for the bg builtin command.
1805 : Does nothing, successfully.
1807 @
1809 @ name = expr
1810 @ name[index] = expr
1811 @ name++|--
1812 @ name[index]++|--
1813 The first form prints the values of all shell variables.
1814 The second form assigns the value of expr to name. The third
1816 form assigns the value of expr to the index'th component of
1817 name; both name and its index'th component must already exist.
1818 expr may contain the operators `*', `+', etc., as in C. If
1820 expr contains `<', `>', `&' or `' then at least that part of
1821 expr must be placed within `()'. Note that the syntax of expr
1822 has nothing to do with that described under Expressions.
1823 The fourth and fifth forms increment (`++') or decrement (`--')
1825 name or its index'th component.
1826 The space between `@' and name is required. The spaces between
1828 name and `=' and between `=' and expr are optional. Components
1829 of expr must be separated by spaces.
1830 alias [name [wordlist]]
1832 Without arguments, prints all aliases. With name, prints the
1833 alias for name. With name and wordlist, assigns wordlist as
1834 the alias of name. wordlist is command and filename substi‐
1835 tuted. name may not be `alias' or `unalias'. See also the
1836 unalias builtin command.
1837 alloc Shows the amount of dynamic memory acquired, broken down into
1839 used and free memory. With an argument shows the number of
1840 free and used blocks in each size category. The categories
1841 start at size 8 and double at each step. This command's output
1842 may vary across system types, because systems other than the
1843 VAX may use a different memory allocator.
1844 bg [%job ...]
1846 Puts the specified jobs (or, without arguments, the current
1847 job) into the background, continuing each if it is stopped.
1848 job may be a number, a string, `', `%', `+' or `-' as described
1849 under Jobs.
1850 bindkey [-l|-d|-e|-v|-u] (+)
1852 bindkey [-a] [-b] [-k] [-r] [--] key (+)
1853 bindkey [-a] [-b] [-k] [-c|-s] [--] key command (+)
1854 Without options, the first form lists all bound keys and the
1855 editor command to which each is bound, the second form lists
1856 the editor command to which key is bound and the third form
1857 binds the editor command command to key. Options include:
1858 -l Lists all editor commands and a short description of each.
1860 -d Binds all keys to the standard bindings for the default
1861 editor, as per -e and -v below.
1862 -e Binds all keys to emacs(1)-style bindings. Unsets vimode.
1863 -v Binds all keys to vi(1)-style bindings. Sets vimode.
1864 -a Lists or changes key-bindings in the alternative key map.
1865 This is the key map used in vimode command mode.
1866 -b key is interpreted as a control character written ^charac‐
1867 ter (e.g., `^A') or C-character (e.g., `C-A'), a meta char‐
1868 acter written M-character (e.g., `M-A'), a function key
1869 written F-string (e.g., `F-string'), or an extended prefix
1870 key written X-character (e.g., `X-A').
1871 -k key is interpreted as a symbolic arrow key name, which may
1872 be one of `down', `up', `left' or `right'.
1873 -r Removes key's binding. Be careful: `bindkey -r' does not
1874 bind key to self-insert-command (q.v.), it unbinds key com‐
1875 pletely.
1876 -c command is interpreted as a builtin or external command
1877 instead of an editor command.
1878 -s command is taken as a literal string and treated as termi‐
1879 nal input when key is typed. Bound keys in command are
1880 themselves reinterpreted, and this continues for ten levels
1881 of interpretation.
1882 -- Forces a break from option processing, so the next word is
1883 taken as key even if it begins with '-'.
1884 -u (or any invalid option)
1885 Prints a usage message.
1886 key may be a single character or a string. If a command is
1888 bound to a string, the first character of the string is bound
1889 to sequence-lead-in and the entire string is bound to the com‐
1890 mand.
1891 Control characters in key can be literal (they can be typed by
1893 preceding them with the editor command quoted-insert, normally
1894 bound to `^V') or written caret-character style, e.g., `^A'.
1895 Delete is written `^?' (caret-question mark). key and command
1896 can contain backslashed escape sequences (in the style of Sys‐
1897 tem V echo(1)) as follows:
1898 \a Bell
1900 \b Backspace
1901 \e Escape
1902 \f Form feed
1903 \n Newline
1904 \r Carriage return
1905 \t Horizontal tab
1906 \v Vertical tab
1907 \nnn The ASCII character corresponding to the octal num‐
1908 ber nnn
1909 `\' nullifies the special meaning of the following character,
1911 if it has any, notably `\' and `^'.
1912 bs2cmd bs2000-command (+)
1914 Passes bs2000-command to the BS2000 command interpreter for
1915 execution. Only non-interactive commands can be executed, and
1916 it is not possible to execute any command that would overlay
1917 the image of the current process, like /EXECUTE or /CALL-PROCE‐
1918 DURE. (BS2000 only)
1919 break Causes execution to resume after the end of the nearest enclos‐
1921 ing foreach or while. The remaining commands on the current
1922 line are executed. Multi-level breaks are thus possible by
1923 writing them all on one line.
1924 breaksw Causes a break from a switch, resuming after the endsw.
1926 builtins (+)
1928 Prints the names of all builtin commands.
1929 bye (+) A synonym for the logout builtin command. Available only if
1931 the shell was so compiled; see the version shell variable.
1932 case label:
1934 A label in a switch statement as discussed below.
1935 cd [-p] [-l] [-n|-v] [I--] [name]
1937 If a directory name is given, changes the shell's working
1938 directory to name. If not, changes to home, unless the cdto‐
1939 home variable is not set, in which case a name is required. If
1940 name is `-' it is interpreted as the previous working directory
1941 (see Other substitutions). (+) If name is not a subdirectory
1942 of the current directory (and does not begin with `/', `./' or
1943 `../'), each component of the variable cdpath is checked to see
1944 if it has a subdirectory name. Finally, if all else fails but
1945 name is a shell variable whose value begins with `/' or '.',
1946 then this is tried to see if it is a directory, and the -p
1947 option is implied.
1948 With -p, prints the final directory stack, just like dirs. The
1950 -l, -n and -v flags have the same effect on cd as on dirs, and
1951 they imply -p. (+) Using -- forces a break from option pro‐
1952 cessing so the next word is taken as the directory name even if
1953 it begins with '-'. (+)
1954 See also the implicitcd and cdtohome shell variables.
1956 chdir A synonym for the cd builtin command.
1958 complete [command [word/pattern/list[:select]/[[suffix]/] ...]] (+)
1960 Without arguments, lists all completions. With command, lists
1961 completions for command. With command and word etc., defines
1962 completions.
1963 command may be a full command name or a glob-pattern (see File‐
1965 name substitution). It can begin with `-' to indicate that
1966 completion should be used only when command is ambiguous.
1967 word specifies which word relative to the current word is to be
1969 completed, and may be one of the following:
1970 c Current-word completion. pattern is a glob-pattern
1972 which must match the beginning of the current word on
1973 the command line. pattern is ignored when completing
1974 the current word.
1975 C Like c, but includes pattern when completing the cur‐
1976 rent word.
1977 n Next-word completion. pattern is a glob-pattern which
1978 must match the beginning of the previous word on the
1979 command line.
1980 N Like n, but must match the beginning of the word two
1981 before the current word.
1982 p Position-dependent completion. pattern is a numeric
1983 range, with the same syntax used to index shell vari‐
1984 ables, which must include the current word.
1985 list, the list of possible completions, may be one of the fol‐
1987 lowing:
1988 a Aliases
1990 b Bindings (editor commands)
1991 c Commands (builtin or external commands)
1992 C External commands which begin with the supplied
1993 path prefix
1994 d Directories
1995 D Directories which begin with the supplied path pre‐
1996 fix
1997 e Environment variables
1998 f Filenames
1999 F Filenames which begin with the supplied path prefix
2000 g Groupnames
2001 j Jobs
2002 l Limits
2003 n Nothing
2004 s Shell variables
2005 S Signals
2006 t Plain (``text'') files
2007 T Plain (``text'') files which begin with the sup‐
2008 plied path prefix
2009 v Any variables
2010 u Usernames
2011 x Like n, but prints select when list-choices is
2012 used.
2013 X Completions
2014 $var Words from the variable var
2015 (...) Words from the given list
2016 `...` Words from the output of command
2017 select is an optional glob-pattern. If given, words from only
2019 list that match select are considered and the fignore shell
2020 variable is ignored. The last three types of completion may
2021 not have a select pattern, and x uses select as an explanatory
2022 message when the list-choices editor command is used.
2023 suffix is a single character to be appended to a successful
2025 completion. If null, no character is appended. If omitted (in
2026 which case the fourth delimiter can also be omitted), a slash
2027 is appended to directories and a space to other words.
2028 command invoked from `...` version has additional environment
2030 variable set, the variable name is COMMAND_LINE and contains
2031 (as its name indicates) contents of the current (already typed
2032 in) command line. One can examine and use contents of the
2033 COMMAND_LINE variable in her custom script to build more
2034 sophisticated completions (see completion for svn(1) included
2035 in this package).
2036 Now for some examples. Some commands take only directories as
2038 arguments, so there's no point completing plain files.
2039 > complete cd 'p/1/d/'
2041 completes only the first word following `cd' (`p/1') with a
2043 directory. p-type completion can also be used to narrow down
2044 command completion:
2045 > co[^D]
2047 complete compress
2048 > complete -co* 'p/0/(compress)/'
2049 > co[^D]
2050 > compress
2051 This completion completes commands (words in position 0, `p/0')
2053 which begin with `co' (thus matching `co*') to `compress' (the
2054 only word in the list). The leading `-' indicates that this
2055 completion is to be used with only ambiguous commands.
2056 > complete find 'n/-user/u/'
2058 is an example of n-type completion. Any word following `find'
2060 and immediately following `-user' is completed from the list of
2061 users.
2062 > complete cc 'c/-I/d/'
2064 demonstrates c-type completion. Any word following `cc' and
2066 beginning with `-I' is completed as a directory. `-I' is not
2067 taken as part of the directory because we used lowercase c.
2068 Different lists are useful with different commands.
2070 > complete alias 'p/1/a/'
2072 > complete man 'p/*/c/'
2073 > complete set 'p/1/s/'
2074 > complete true 'p/1/x:Truth has no options./'
2075 These complete words following `alias' with aliases, `man' with
2077 commands, and `set' with shell variables. `true' doesn't have
2078 any options, so x does nothing when completion is attempted and
2079 prints `Truth has no options.' when completion choices are
2080 listed.
2081 Note that the man example, and several other examples below,
2083 could just as well have used 'c/*' or 'n/*' as 'p/*'.
2084 Words can be completed from a variable evaluated at completion
2086 time,
2087 > complete ftp 'p/1/$hostnames/'
2089 > set hostnames = (rtfm.mit.edu tesla.ee.cornell.edu)
2090 > ftp [^D]
2091 rtfm.mit.edu tesla.ee.cornell.edu
2092 > ftp [^C]
2093 > set hostnames = (rtfm.mit.edu tesla.ee.cornell.edu
2094 uunet.uu.net)
2095 > ftp [^D]
2096 rtfm.mit.edu tesla.ee.cornell.edu uunet.uu.net
2097 or from a command run at completion time:
2099 > complete kill 'p/*/`ps | awk \{print\ \$1\}`/'
2101 > kill -9 [^D]
2102 23113 23377 23380 23406 23429 23529 23530 PID
2103 Note that the complete command does not itself quote its argu‐
2105 ments, so the braces, space and `$' in `{print $1}' must be
2106 quoted explicitly.
2107 One command can have multiple completions:
2109 > complete dbx 'p/2/(core)/' 'p/*/c/'
2111 completes the second argument to `dbx' with the word `core' and
2113 all other arguments with commands. Note that the positional
2114 completion is specified before the next-word completion.
2115 Because completions are evaluated from left to right, if the
2116 next-word completion were specified first it would always match
2117 and the positional completion would never be executed. This is
2118 a common mistake when defining a completion.
2119 The select pattern is useful when a command takes files with
2121 only particular forms as arguments. For example,
2122 > complete cc 'p/*/f:*.[cao]/'
2124 completes `cc' arguments to files ending in only `.c', `.a', or
2126 `.o'. select can also exclude files, using negation of a glob-
2127 pattern as described under Filename substitution. One might
2128 use
2129 > complete rm 'p/*/f:^*.{c,h,cc,C,tex,1,man,l,y}/'
2131 to exclude precious source code from `rm' completion. Of
2133 course, one could still type excluded names manually or over‐
2134 ride the completion mechanism using the complete-word-raw or
2135 list-choices-raw editor commands (q.v.).
2136 The `C', `D', `F' and `T' lists are like `c', `d', `f' and `t'
2138 respectively, but they use the select argument in a different
2139 way: to restrict completion to files beginning with a particu‐
2140 lar path prefix. For example, the Elm mail program uses `=' as
2141 an abbreviation for one's mail directory. One might use
2142 > complete elm c@=@F:$HOME/Mail/@
2144 to complete `elm -f =' as if it were `elm -f ~/Mail/'. Note
2146 that we used `@' instead of `/' to avoid confusion with the
2147 select argument, and we used `$HOME' instead of `~' because
2148 home directory substitution works at only the beginning of a
2149 word.
2150 suffix is used to add a nonstandard suffix (not space or `/'
2152 for directories) to completed words.
2153 > complete finger 'c/*@/$hostnames/' 'p/1/u/@'
2155 completes arguments to `finger' from the list of users, appends
2157 an `@', and then completes after the `@' from the `hostnames'
2158 variable. Note again the order in which the completions are
2159 specified.
2160 Finally, here's a complex example for inspiration:
2162 > complete find \
2164 'n/-name/f/' 'n/-newer/f/' 'n/-{,n}cpio/f/' \
2165 ´n/-exec/c/' 'n/-ok/c/' 'n/-user/u/' \
2166 'n/-group/g/' 'n/-fstype/(nfs 4.2)/' \
2167 'n/-type/(b c d f l p s)/' \
2168 ´c/-/(name newer cpio ncpio exec ok user \
2169 group fstype type atime ctime depth inum \
2170 ls mtime nogroup nouser perm print prune \
2171 size xdev)/' \
2172 'p/*/d/'
2173 This completes words following `-name', `-newer', `-cpio' or
2175 `ncpio' (note the pattern which matches both) to files, words
2176 following `-exec' or `-ok' to commands, words following `user'
2177 and `group' to users and groups respectively and words follow‐
2178 ing `-fstype' or `-type' to members of the given lists. It
2179 also completes the switches themselves from the given list
2180 (note the use of c-type completion) and completes anything not
2181 otherwise completed to a directory. Whew.
2182 Remember that programmed completions are ignored if the word
2184 being completed is a tilde substitution (beginning with `~') or
2185 a variable (beginning with `$'). See also the uncomplete
2186 builtin command.
2187 continue
2189 Continues execution of the nearest enclosing while or foreach.
2190 The rest of the commands on the current line are executed.
2191 default:
2193 Labels the default case in a switch statement. It should come
2194 after all case labels.
2195 dirs [-l] [-n|-v]
2197 dirs -S|-L [filename] (+)
2198 dirs -c (+)
2199 The first form prints the directory stack. The top of the
2200 stack is at the left and the first directory in the stack is
2201 the current directory. With -l, `~' or `~name' in the output
2202 is expanded explicitly to home or the pathname of the home
2203 directory for user name. (+) With -n, entries are wrapped
2204 before they reach the edge of the screen. (+) With -v, entries
2205 are printed one per line, preceded by their stack positions.
2206 (+) If more than one of -n or -v is given, -v takes precedence.
2207 -p is accepted but does nothing.
2208 With -S, the second form saves the directory stack to filename
2210 as a series of cd and pushd commands. With -L, the shell
2211 sources filename, which is presumably a directory stack file
2212 saved by the -S option or the savedirs mechanism. In either
2213 case, dirsfile is used if filename is not given and ~/.cshdirs
2214 is used if dirsfile is unset.
2215 Note that login shells do the equivalent of `dirs -L' on
2217 startup and, if savedirs is set, `dirs -S' before exiting.
2218 Because only ~/.tcshrc is normally sourced before ~/.cshdirs,
2219 dirsfile should be set in ~/.tcshrc rather than ~/.login.
2220 The last form clears the directory stack.
2222 echo [-n] word ...
2224 Writes each word to the shell's standard output, separated by
2225 spaces and terminated with a newline. The echo_style shell
2226 variable may be set to emulate (or not) the flags and escape
2227 sequences of the BSD and/or System V versions of echo; see
2228 echo(1).
2229 echotc [-sv] arg ... (+)
2231 Exercises the terminal capabilities (see termcap(5)) in args.
2232 For example, 'echotc home' sends the cursor to the home posi‐
2233 tion, 'echotc cm 3 10' sends it to column 3 and row 10, and
2234 'echotc ts 0; echo "This is a test."; echotc fs' prints "This
2235 is a test." in the status line.
2236 If arg is 'baud', 'cols', 'lines', 'meta' or 'tabs', prints the
2238 value of that capability ("yes" or "no" indicating that the
2239 terminal does or does not have that capability). One might use
2240 this to make the output from a shell script less verbose on
2241 slow terminals, or limit command output to the number of lines
2242 on the screen:
2243 > set history=`echotc lines`
2245 > @ history--
2246 Termcap strings may contain wildcards which will not echo cor‐
2248 rectly. One should use double quotes when setting a shell
2249 variable to a terminal capability string, as in the following
2250 example that places the date in the status line:
2251 > set tosl="`echotc ts 0`"
2253 > set frsl="`echotc fs`"
2254 > echo -n "$tosl";date; echo -n "$frsl"
2255 With -s, nonexistent capabilities return the empty string
2257 rather than causing an error. With -v, messages are verbose.
2258 else
2260 end
2261 endif
2262 endsw See the description of the foreach, if, switch, and while
2263 statements below.
2264 eval arg ...
2266 Treats the arguments as input to the shell and executes the
2267 resulting command(s) in the context of the current shell. This
2268 is usually used to execute commands generated as the result of
2269 command or variable substitution, because parsing occurs before
2270 these substitutions. See tset(1) for a sample use of eval.
2271 exec command
2273 Executes the specified command in place of the current shell.
2274 exit [expr]
2276 The shell exits either with the value of the specified expr (an
2277 expression, as described under Expressions) or, without expr,
2278 with the value 0.
2279 fg [%job ...]
2281 Brings the specified jobs (or, without arguments, the current
2282 job) into the foreground, continuing each if it is stopped.
2283 job may be a number, a string, `', `%', `+' or `-' as described
2284 under Jobs. See also the run-fg-editor editor command.
2285 filetest -op file ... (+)
2287 Applies op (which is a file inquiry operator as described under
2288 File inquiry operators) to each file and returns the results as
2289 a space-separated list.
2290 foreach name (wordlist)
2292 ...
2293 end Successively sets the variable name to each member of wordlist
2294 and executes the sequence of commands between this command and
2295 the matching end. (Both foreach and end must appear alone on
2296 separate lines.) The builtin command continue may be used to
2297 continue the loop prematurely and the builtin command break to
2298 terminate it prematurely. When this command is read from the
2299 terminal, the loop is read once prompting with `foreach? ' (or
2300 prompt2) before any statements in the loop are executed. If
2301 you make a mistake typing in a loop at the terminal you can rub
2302 it out.
2303 getspath (+)
2305 Prints the system execution path. (TCF only)
2306 getxvers (+)
2308 Prints the experimental version prefix. (TCF only)
2309 glob wordlist
2311 Like echo, but the `-n' parameter is not recognized and words
2312 are delimited by null characters in the output. Useful for
2313 programs which wish to use the shell to filename expand a list
2314 of words.
2315 goto word
2317 word is filename and command-substituted to yield a string of
2318 the form `label'. The shell rewinds its input as much as pos‐
2319 sible, searches for a line of the form `label:', possibly pre‐
2320 ceded by blanks or tabs, and continues execution after that
2321 line.
2322 hashstat
2324 Prints a statistics line indicating how effective the internal
2325 hash table has been at locating commands (and avoiding exec's).
2326 An exec is attempted for each component of the path where the
2327 hash function indicates a possible hit, and in each component
2328 which does not begin with a `/'.
2329 On machines without vfork(2), prints only the number and size
2331 of hash buckets.
2332 history [-hTr] [n]
2334 history -S|-L|-M [filename] (+)
2335 history -c (+)
2336 The first form prints the history event list. If n is given
2337 only the n most recent events are printed or saved. With -h,
2338 the history list is printed without leading numbers. If -T is
2339 specified, timestamps are printed also in comment form. (This
2340 can be used to produce files suitable for loading with 'history
2341 -L' or 'source -h'.) With -r, the order of printing is most
2342 recent first rather than oldest first.
2343 With -S, the second form saves the history list to filename.
2345 If the first word of the savehist shell variable is set to a
2346 number, at most that many lines are saved. If the second word
2347 of savehist is set to `merge', the history list is merged with
2348 the existing history file instead of replacing it (if there is
2349 one) and sorted by time stamp. (+) Merging is intended for an
2350 environment like the X Window System with several shells in
2351 simultaneous use. If the second word of savehist is `merge'
2352 and the third word is set to `lock', the history file update
2353 will be serialized with other shell sessions that would possi‐
2354 bly like to merge history at exactly the same time.
2355 With -L, the shell appends filename, which is presumably a his‐
2357 tory list saved by the -S option or the savehist mechanism, to
2358 the history list. -M is like -L, but the contents of filename
2359 are merged into the history list and sorted by timestamp. In
2360 either case, histfile is used if filename is not given and
2361 ~/.history is used if histfile is unset. `history -L' is
2362 exactly like 'source -h' except that it does not require a
2363 filename.
2364 Note that login shells do the equivalent of `history -L' on
2366 startup and, if savehist is set, `history -S' before exiting.
2367 Because only ~/.tcshrc is normally sourced before ~/.history,
2368 histfile should be set in ~/.tcshrc rather than ~/.login.
2369 If histlit is set, the first and second forms print and save
2371 the literal (unexpanded) form of the history list.
2372 The last form clears the history list.
2374 hup [command] (+)
2376 With command, runs command such that it will exit on a hangup
2377 signal and arranges for the shell to send it a hangup signal
2378 when the shell exits. Note that commands may set their own
2379 response to hangups, overriding hup. Without an argument,
2380 causes the non-interactive shell only to exit on a hangup for
2381 the remainder of the script. See also Signal handling and the
2382 nohup builtin command.
2383 if (expr) command
2385 If expr (an expression, as described under Expressions) evalu‐
2386 ates true, then command is executed. Variable substitution on
2387 command happens early, at the same time it does for the rest of
2388 the if command. command must be a simple command, not an
2389 alias, a pipeline, a command list or a parenthesized command
2390 list, but it may have arguments. Input/output redirection
2391 occurs even if expr is false and command is thus not executed;
2392 this is a bug.
2393 if (expr) then
2395 ...
2396 else if (expr2) then
2397 ...
2398 else
2399 ...
2400 endif If the specified expr is true then the commands to the first
2401 else are executed; otherwise if expr2 is true then the commands
2402 to the second else are executed, etc. Any number of else-if
2403 pairs are possible; only one endif is needed. The else part is
2404 likewise optional. (The words else and endif must appear at
2405 the beginning of input lines; the if must appear alone on its
2406 input line or after an else.)
2407 inlib shared-library ... (+)
2409 Adds each shared-library to the current environment. There is
2410 no way to remove a shared library. (Domain/OS only)
2411 jobs [-l]
2413 Lists the active jobs. With -l, lists process IDs in addition
2414 to the normal information. On TCF systems, prints the site on
2415 which each job is executing.
2416 kill [-s signal] %job|pid ...
2418 kill -l The first and second forms sends the specified signal (or, if
2419 none is given, the TERM (terminate) signal) to the specified
2420 jobs or processes. job may be a number, a string, `', `%', `+'
2421 or `-' as described under Jobs. Signals are either given by
2422 number or by name (as given in /usr/include/signal.h, stripped
2423 of the prefix `SIG'). There is no default job; saying just
2424 `kill' does not send a signal to the current job. If the sig‐
2425 nal being sent is TERM (terminate) or HUP (hangup), then the
2426 job or process is sent a CONT (continue) signal as well. The
2427 third form lists the signal names.
2428 limit [-h] [resource [maximum-use]]
2430 Limits the consumption by the current process and each process
2431 it creates to not individually exceed maximum-use on the speci‐
2432 fied resource. If no maximum-use is given, then the current
2433 limit is printed; if no resource is given, then all limitations
2434 are given. If the -h flag is given, the hard limits are used
2435 instead of the current limits. The hard limits impose a ceil‐
2436 ing on the values of the current limits. Only the super-user
2437 may raise the hard limits, but a user may lower or raise the
2438 current limits within the legal range.
2439 Controllable resources currently include (if supported by the
2441 OS):
2442 cputime
2444 the maximum number of cpu-seconds to be used by each
2445 process
2446 filesize
2448 the largest single file which can be created
2449 datasize
2451 the maximum growth of the data+stack region via sbrk(2)
2452 beyond the end of the program text
2453 stacksize
2455 the maximum size of the automatically-extended stack
2456 region
2457 coredumpsize
2459 the size of the largest core dump that will be created
2460 memoryuse
2462 the maximum amount of physical memory a process may have
2463 allocated to it at a given time
2464 NOTE: Changing this value has no effect. Support has
2466 been removed from Linux kernel v2.6 and newer.
2467 vmemoryuse
2469 the maximum amount of virtual memory a process may have
2470 allocated to it at a given time (address space)
2471 vmemoryuse
2473 the maximum amount of virtual memory a process may have
2474 allocated to it at a given time
2475 heapsize
2477 the maximum amount of memory a process may allocate per
2478 brk() system call
2479 descriptors or openfiles
2481 the maximum number of open files for this process
2482 pseudoterminals
2484 the maximum number of pseudo-terminals for this user
2485 kqueues
2487 the maximum number of kqueues allocated for this process
2488 concurrency
2490 the maximum number of threads for this process
2491 memorylocked
2493 the maximum size which a process may lock into memory
2494 using mlock(2)
2495 maxproc
2497 the maximum number of simultaneous processes for this
2498 user id
2499 maxthread
2501 the maximum number of simultaneous threads (lightweight
2502 processes) for this user id
2503 threads
2505 the maximum number of threads for this process
2506 sbsize the maximum size of socket buffer usage for this user
2508 swapsize
2510 the maximum amount of swap space reserved or used for
2511 this user
2512 maxlocks
2514 the maximum number of locks for this user
2515 posixlocks
2517 the maximum number of POSIX advisory locks for this user
2518 maxsignal
2520 the maximum number of pending signals for this user
2521 maxmessage
2523 the maximum number of bytes in POSIX mqueues for this
2524 user
2525 maxnice
2527 the maximum nice priority the user is allowed to raise
2528 mapped from [19...-20] to [0...39] for this user
2529 maxrtprio
2531 the maximum realtime priority for this user maxrttime
2532 the timeout for RT tasks in microseconds for this user.
2533 maximum-use may be given as a (floating point or integer) num‐
2535 ber followed by a scale factor. For all limits other than
2536 cputime the default scale is `k' or `kilobytes' (1024 bytes); a
2537 scale factor of `m' or `megabytes' or `g' or `gigabytes' may
2538 also be used. For cputime the default scaling is `seconds',
2539 while `m' for minutes or `h' for hours, or a time of the form
2540 `mm:ss' giving minutes and seconds may be used.
2541 If maximum-use is `unlimited', then the limitation on the
2543 specified resource is removed (this is equivalent to the
2544 unlimit builtin command).
2545 For both resource names and scale factors, unambiguous prefixes
2547 of the names suffice.
2548 log (+) Prints the watch shell variable and reports on each user indi‐
2550 cated in watch who is logged in, regardless of when they last
2551 logged in. See also watchlog.
2552 login Terminates a login shell, replacing it with an instance of
2554 /bin/login. This is one way to log off, included for compati‐
2555 bility with sh(1).
2556 logout Terminates a login shell. Especially useful if ignoreeof is
2558 set.
2559 ls-F [-switch ...] [file ...] (+)
2561 Lists files like `ls -F', but much faster. It identifies each
2562 type of special file in the listing with a special character:
2563 / Directory
2565 * Executable
2566 # Block device
2567 % Character device
2568 | Named pipe (systems with named pipes only)
2569 = Socket (systems with sockets only)
2570 @ Symbolic link (systems with symbolic links only)
2571 + Hidden directory (AIX only) or context dependent (HP/UX
2572 only)
2573 : Network special (HP/UX only)
2574 If the listlinks shell variable is set, symbolic links are
2576 identified in more detail (on only systems that have them, of
2577 course):
2578 @ Symbolic link to a non-directory
2580 > Symbolic link to a directory
2581 & Symbolic link to nowhere
2582 listlinks also slows down ls-F and causes partitions holding
2584 files pointed to by symbolic links to be mounted.
2585 If the listflags shell variable is set to `x', `a' or `A', or
2587 any combination thereof (e.g., `xA'), they are used as flags to
2588 ls-F, making it act like `ls -xF', `ls -Fa', `ls -FA' or a com‐
2589 bination (e.g., `ls -FxA'). On machines where `ls -C' is not
2590 the default, ls-F acts like `ls -CF', unless listflags contains
2591 an `x', in which case it acts like `ls -xF'. ls-F passes its
2592 arguments to ls(1) if it is given any switches, so `alias ls
2593 ls-F' generally does the right thing.
2594 The ls-F builtin can list files using different colors depend‐
2596 ing on the filetype or extension. See the color shell variable
2597 and the LS_COLORS environment variable.
2598 migrate [-site] pid|%jobid ... (+)
2600 migrate -site (+)
2601 The first form migrates the process or job to the site speci‐
2602 fied or the default site determined by the system path. The
2603 second form is equivalent to `migrate -site $$': it migrates
2604 the current process to the specified site. Migrating the shell
2605 itself can cause unexpected behavior, because the shell does
2606 not like to lose its tty. (TCF only)
2607 newgrp [-] [group] (+)
2609 Equivalent to `exec newgrp'; see newgrp(1). Available only if
2610 the shell was so compiled; see the version shell variable.
2611 nice [+number] [command]
2613 Sets the scheduling priority for the shell to number, or, with‐
2614 out number, to 4. With command, runs command at the appropri‐
2615 ate priority. The greater the number, the less cpu the process
2616 gets. The super-user may specify negative priority by using
2617 `nice -number ...'. Command is always executed in a sub-shell,
2618 and the restrictions placed on commands in simple if statements
2619 apply.
2620 nohup [command]
2622 With command, runs command such that it will ignore hangup sig‐
2623 nals. Note that commands may set their own response to
2624 hangups, overriding nohup. Without an argument, causes the
2625 non-interactive shell only to ignore hangups for the remainder
2626 of the script. See also Signal handling and the hup builtin
2627 command.
2628 notify [%job ...]
2630 Causes the shell to notify the user asynchronously when the
2631 status of any of the specified jobs (or, without %job, the cur‐
2632 rent job) changes, instead of waiting until the next prompt as
2633 is usual. job may be a number, a string, `', `%', `+' or `-'
2634 as described under Jobs. See also the notify shell variable.
2635 onintr [-|label]
2637 Controls the action of the shell on interrupts. Without argu‐
2638 ments, restores the default action of the shell on interrupts,
2639 which is to terminate shell scripts or to return to the termi‐
2640 nal command input level. With `-', causes all interrupts to be
2641 ignored. With label, causes the shell to execute a `goto
2642 label' when an interrupt is received or a child process termi‐
2643 nates because it was interrupted.
2644 onintr is ignored if the shell is running detached and in sys‐
2646 tem startup files (see FILES), where interrupts are disabled
2647 anyway.
2648 popd [-p] [-l] [-n|-v] [+n]
2650 Without arguments, pops the directory stack and returns to the
2651 new top directory. With a number `+n', discards the n'th entry
2652 in the stack.
2653 Finally, all forms of popd print the final directory stack,
2655 just like dirs. The pushdsilent shell variable can be set to
2656 prevent this and the -p flag can be given to override pushdsi‐
2657 lent. The -l, -n and -v flags have the same effect on popd as
2658 on dirs. (+)
2659 printenv [name] (+)
2661 Prints the names and values of all environment variables or,
2662 with name, the value of the environment variable name.
2663 pushd [-p] [-l] [-n|-v] [name|+n]
2665 Without arguments, exchanges the top two elements of the direc‐
2666 tory stack. If pushdtohome is set, pushd without arguments
2667 does `pushd ~', like cd. (+) With name, pushes the current
2668 working directory onto the directory stack and changes to name.
2669 If name is `-' it is interpreted as the previous working direc‐
2670 tory (see Filename substitution). (+) If dunique is set, pushd
2671 removes any instances of name from the stack before pushing it
2672 onto the stack. (+) With a number `+n', rotates the nth ele‐
2673 ment of the directory stack around to be the top element and
2674 changes to it. If dextract is set, however, `pushd +n'
2675 extracts the nth directory, pushes it onto the top of the stack
2676 and changes to it. (+)
2677 Finally, all forms of pushd print the final directory stack,
2679 just like dirs. The pushdsilent shell variable can be set to
2680 prevent this and the -p flag can be given to override pushdsi‐
2681 lent. The -l, -n and -v flags have the same effect on pushd as
2682 on dirs. (+)
2683 rehash Causes the internal hash table of the contents of the directo‐
2685 ries in the path variable to be recomputed. This is needed if
2686 the autorehash shell variable is not set and new commands are
2687 added to directories in path while you are logged in. With
2688 autorehash, a new command will be found automatically, except
2689 in the special case where another command of the same name
2690 which is located in a different directory already exists in the
2691 hash table. Also flushes the cache of home directories built
2692 by tilde expansion.
2693 repeat count command
2695 The specified command, which is subject to the same restric‐
2696 tions as the command in the one line if statement above, is
2697 executed count times. I/O redirections occur exactly once,
2698 even if count is 0.
2699 rootnode //nodename (+)
2701 Changes the rootnode to //nodename, so that `/' will be inter‐
2702 preted as `//nodename'. (Domain/OS only)
2703 sched (+)
2705 sched [+]hh:mm command (+)
2706 sched -n (+)
2707 The first form prints the scheduled-event list. The sched
2708 shell variable may be set to define the format in which the
2709 scheduled-event list is printed. The second form adds command
2710 to the scheduled-event list. For example,
2711 > sched 11:00 echo It\'s eleven o\'clock.
2713 causes the shell to echo `It's eleven o'clock.' at 11 AM. The
2715 time may be in 12-hour AM/PM format
2716 > sched 5pm set prompt='[%h] It\'s after 5; go home: >'
2718 or may be relative to the current time:
2720 > sched +2:15 /usr/lib/uucp/uucico -r1 -sother
2722 A relative time specification may not use AM/PM format. The
2724 third form removes item n from the event list:
2725 > sched
2727 1 Wed Apr 4 15:42 /usr/lib/uucp/uucico -r1 -sother
2728 2 Wed Apr 4 17:00 set prompt=[%h] It's after 5; go
2729 home: >
2730 > sched -2
2731 > sched
2732 1 Wed Apr 4 15:42 /usr/lib/uucp/uucico -r1 -sother
2733 A command in the scheduled-event list is executed just before
2735 the first prompt is printed after the time when the command is
2736 scheduled. It is possible to miss the exact time when the com‐
2737 mand is to be run, but an overdue command will execute at the
2738 next prompt. A command which comes due while the shell is
2739 waiting for user input is executed immediately. However, nor‐
2740 mal operation of an already-running command will not be inter‐
2741 rupted so that a scheduled-event list element may be run.
2742 This mechanism is similar to, but not the same as, the at(1)
2744 command on some Unix systems. Its major disadvantage is that
2745 it may not run a command at exactly the specified time. Its
2746 major advantage is that because sched runs directly from the
2747 shell, it has access to shell variables and other structures.
2748 This provides a mechanism for changing one's working environ‐
2749 ment based on the time of day.
2750 set
2752 set name ...
2753 set name=word ...
2754 set [-r] [-f|-l] name=(wordlist) ... (+)
2755 set name[index]=word ...
2756 set -r (+)
2757 set -r name ... (+)
2758 set -r name=word ... (+)
2759 The first form of the command prints the value of all shell
2760 variables. Variables which contain more than a single word
2761 print as a parenthesized word list. The second form sets name
2762 to the null string. The third form sets name to the single
2763 word. The fourth form sets name to the list of words in
2764 wordlist. In all cases the value is command and filename
2765 expanded. If -r is specified, the value is set read-only. If
2766 -f or -l are specified, set only unique words keeping their
2767 order. -f prefers the first occurrence of a word, and -l the
2768 last. The fifth form sets the index'th component of name to
2769 word; this component must already exist. The sixth form lists
2770 only the names of all shell variables that are read-only. The
2771 seventh form makes name read-only, whether or not it has a
2772 value. The eighth form is the same as the third form, but make
2773 name read-only at the same time.
2774 These arguments can be repeated to set and/or make read-only
2776 multiple variables in a single set command. Note, however,
2777 that variable expansion happens for all arguments before any
2778 setting occurs. Note also that `=' can be adjacent to both
2779 name and word or separated from both by whitespace, but cannot
2780 be adjacent to only one or the other. See also the unset
2781 builtin command.
2782 setenv [name [value]]
2784 Without arguments, prints the names and values of all environ‐
2785 ment variables. Given name, sets the environment variable name
2786 to value or, without value, to the null string.
2787 setpath path (+)
2789 Equivalent to setpath(1). (Mach only)
2790 setspath LOCAL|site|cpu ... (+)
2792 Sets the system execution path. (TCF only)
2793 settc cap value (+)
2795 Tells the shell to believe that the terminal capability cap (as
2796 defined in termcap(5)) has the value value. No sanity checking
2797 is done. Concept terminal users may have to `settc xn no' to
2798 get proper wrapping at the rightmost column.
2799 setty [-d|-q|-x] [-a] [[+|-]mode] (+)
2801 Controls which tty modes (see Terminal management) the shell
2802 does not allow to change. -d, -q or -x tells setty to act on
2803 the `edit', `quote' or `execute' set of tty modes respectively;
2804 without -d, -q or -x, `execute' is used.
2805 Without other arguments, setty lists the modes in the chosen
2807 set which are fixed on (`+mode') or off (`-mode'). The avail‐
2808 able modes, and thus the display, vary from system to system.
2809 With -a, lists all tty modes in the chosen set whether or not
2810 they are fixed. With +mode, -mode or mode, fixes mode on or
2811 off or removes control from mode in the chosen set. For exam‐
2812 ple, `setty +echok echoe' fixes `echok' mode on and allows com‐
2813 mands to turn `echoe' mode on or off, both when the shell is
2814 executing commands.
2815 setxvers [string] (+)
2817 Set the experimental version prefix to string, or removes it if
2818 string is omitted. (TCF only)
2819 shift [variable]
2821 Without arguments, discards argv[1] and shifts the members of
2822 argv to the left. It is an error for argv not to be set or to
2823 have less than one word as value. With variable, performs the
2824 same function on variable.
2825 source [-h] name [args ...]
2827 The shell reads and executes commands from name. The commands
2828 are not placed on the history list. If any args are given,
2829 they are placed in argv. (+) source commands may be nested; if
2830 they are nested too deeply the shell may run out of file
2831 descriptors. An error in a source at any level terminates all
2832 nested source commands. With -h, commands are placed on the
2833 history list instead of being executed, much like `history -L'.
2834 stop %job|pid ...
2836 Stops the specified jobs or processes which are executing in
2837 the background. job may be a number, a string, `', `%', `+' or
2838 `-' as described under Jobs. There is no default job; saying
2839 just `stop' does not stop the current job.
2840 suspend Causes the shell to stop in its tracks, much as if it had been
2842 sent a stop signal with ^Z. This is most often used to stop
2843 shells started by su(1).
2844 switch (string)
2846 case str1:
2847 ...
2848 breaksw
2849 ...
2850 default:
2851 ...
2852 breaksw
2853 endsw Each case label is successively matched, against the specified
2854 string which is first command and filename expanded. The file
2855 metacharacters `*', `?' and `[...]' may be used in the case
2856 labels, which are variable expanded. If none of the labels
2857 match before a `default' label is found, then the execution
2858 begins after the default label. Each case label and the
2859 default label must appear at the beginning of a line. The com‐
2860 mand breaksw causes execution to continue after the endsw.
2861 Otherwise control may fall through case labels and default
2862 labels as in C. If no label matches and there is no default,
2863 execution continues after the endsw.
2864 telltc (+)
2866 Lists the values of all terminal capabilities (see termcap(5)).
2867 termname [terminal type] (+)
2869 Tests if terminal type (or the current value of TERM if no ter‐
2870 minal type is given) has an entry in the hosts termcap(5) or
2871 terminfo(5) database. Prints the terminal type to stdout and
2872 returns 0 if an entry is present otherwise returns 1.
2873 time [command]
2875 Executes command (which must be a simple command, not an alias,
2876 a pipeline, a command list or a parenthesized command list) and
2877 prints a time summary as described under the time variable. If
2878 necessary, an extra shell is created to print the time statis‐
2879 tic when the command completes. Without command, prints a time
2880 summary for the current shell and its children.
2881 umask [value]
2883 Sets the file creation mask to value, which is given in octal.
2884 Common values for the mask are 002, giving all access to the
2885 group and read and execute access to others, and 022, giving
2886 read and execute access to the group and others. Without
2887 value, prints the current file creation mask.
2888 unalias pattern
2890 Removes all aliases whose names match pattern. `unalias *'
2891 thus removes all aliases. It is not an error for nothing to be
2892 unaliased.
2893 uncomplete pattern (+)
2895 Removes all completions whose names match pattern. `uncomplete
2896 *' thus removes all completions. It is not an error for noth‐
2897 ing to be uncompleted.
2898 unhash Disables use of the internal hash table to speed location of
2900 executed programs.
2901 universe universe (+)
2903 Sets the universe to universe. (Masscomp/RTU only)
2904 unlimit [-hf] [resource]
2906 Removes the limitation on resource or, if no resource is speci‐
2907 fied, all resource limitations. With -h, the corresponding
2908 hard limits are removed. Only the super-user may do this.
2909 Note that unlimit may not exit successful, since most systems
2910 do not allow descriptors to be unlimited. With -f errors are
2911 ignored.
2912 unset pattern
2914 Removes all variables whose names match pattern, unless they
2915 are read-only. `unset *' thus removes all variables unless
2916 they are read-only; this is a bad idea. It is not an error for
2917 nothing to be unset.
2918 unsetenv pattern
2920 Removes all environment variables whose names match pattern.
2921 `unsetenv *' thus removes all environment variables; this is a
2922 bad idea. It is not an error for nothing to be unsetenved.
2923 ver [systype [command]] (+)
2925 Without arguments, prints SYSTYPE. With systype, sets SYSTYPE
2926 to systype. With systype and command, executes command under
2927 systype. systype may be `bsd4.3' or `sys5.3'. (Domain/OS
2928 only)
2929 wait The shell waits for all background jobs. If the shell is
2931 interactive, an interrupt will disrupt the wait and cause the
2932 shell to print the names and job numbers of all outstanding
2933 jobs.
2934 warp universe (+)
2936 Sets the universe to universe. (Convex/OS only)
2937 watchlog (+)
2939 An alternate name for the log builtin command (q.v.). Avail‐
2940 able only if the shell was so compiled; see the version shell
2941 variable.
2942 where command (+)
2944 Reports all known instances of command, including aliases,
2945 builtins and executables in path.
2946 which command (+)
2948 Displays the command that will be executed by the shell after
2949 substitutions, path searching, etc. The builtin command is
2950 just like which(1), but it correctly reports tcsh aliases and
2951 builtins and is 10 to 100 times faster. See also the which-
2952 command editor command.
2953 while (expr)
2955 ...
2956 end Executes the commands between the while and the matching end
2957 while expr (an expression, as described under Expressions)
2958 evaluates non-zero. while and end must appear alone on their
2959 input lines. break and continue may be used to terminate or
2960 continue the loop prematurely. If the input is a terminal, the
2961 user is prompted the first time through the loop as with fore‐
2962 ach.
2963 Special aliases (+)
2965 If set, each of these aliases executes automatically at the indicated
2966 time. They are all initially undefined.
2967 beepcmd Runs when the shell wants to ring the terminal bell.
2969 cwdcmd Runs after every change of working directory. For example, if
2971 the user is working on an X window system using xterm(1) and a
2972 re-parenting window manager that supports title bars such as
2973 twm(1) and does
2974 > alias cwdcmd 'echo -n "^[]2;${HOST}:$cwd ^G"'
2976 then the shell will change the title of the running xterm(1) to
2978 be the name of the host, a colon, and the full current working
2979 directory. A fancier way to do that is
2980 > alias cwdcmd 'echo -n
2982 "^[]2;${HOST}:$cwd^G^[]1;${HOST}^G"'
2983 This will put the hostname and working directory on the title
2985 bar but only the hostname in the icon manager menu.
2986 Note that putting a cd, pushd or popd in cwdcmd may cause an
2988 infinite loop. It is the author's opinion that anyone doing so
2989 will get what they deserve.
2990 jobcmd Runs before each command gets executed, or when the command
2992 changes state. This is similar to postcmd, but it does not
2993 print builtins.
2994 > alias jobcmd 'echo -n "^[]2\;\!#:q^G"'
2996 then executing vi foo.c will put the command string in the
2998 xterm title bar.
2999 helpcommand
3001 Invoked by the run-help editor command. The command name for
3002 which help is sought is passed as sole argument. For example,
3003 if one does
3004 > alias helpcommand '\!:1 --help'
3006 then the help display of the command itself will be invoked,
3008 using the GNU help calling convention. Currently there is no
3009 easy way to account for various calling conventions (e.g., the
3010 customary Unix `-h'), except by using a table of many commands.
3011 periodic
3013 Runs every tperiod minutes. This provides a convenient means
3014 for checking on common but infrequent changes such as new mail.
3015 For example, if one does
3016 > set tperiod = 30
3018 > alias periodic checknews
3019 then the checknews(1) program runs every 30 minutes. If peri‐
3021 odic is set but tperiod is unset or set to 0, periodic behaves
3022 like precmd.
3023 precmd Runs just before each prompt is printed. For example, if one
3025 does
3026 > alias precmd date
3028 then date(1) runs just before the shell prompts for each com‐
3030 mand. There are no limits on what precmd can be set to do, but
3031 discretion should be used.
3032 postcmd Runs before each command gets executed.
3034 > alias postcmd 'echo -n "^[]2\;\!#:q^G"'
3036 then executing vi foo.c will put the command string in the
3038 xterm title bar.
3039 shell Specifies the interpreter for executable scripts which do not
3041 themselves specify an interpreter. The first word should be a
3042 full path name to the desired interpreter (e.g., `/bin/csh' or
3043 `/usr/local/bin/tcsh').
3044 Special shell variables
3046 The variables described in this section have special meaning to the
3047 shell.
3048 The shell sets addsuffix, argv, autologout, csubstnonl, command,
3050 echo_style, edit, gid, group, home, loginsh, oid, path, prompt,
3051 prompt2, prompt3, shell, shlvl, tcsh, term, tty, uid, user and version
3052 at startup; they do not change thereafter unless changed by the user.
3053 The shell updates cwd, dirstack, owd and status when necessary, and
3054 sets logout on logout.
3055 The shell synchronizes group, home, path, shlvl, term and user with the
3057 environment variables of the same names: whenever the environment vari‐
3058 able changes the shell changes the corresponding shell variable to
3059 match (unless the shell variable is read-only) and vice versa. Note
3060 that although cwd and PWD have identical meanings, they are not syn‐
3061 chronized in this manner, and that the shell automatically converts
3062 between the different formats of path and PATH.
3063 addsuffix (+)
3065 If set, filename completion adds `/' to the end of directories
3066 and a space to the end of normal files when they are matched
3067 exactly. Set by default.
3068 afsuser (+)
3070 If set, autologout's autolock feature uses its value instead of
3071 the local username for kerberos authentication.
3072 ampm (+)
3074 If set, all times are shown in 12-hour AM/PM format.
3075 anyerror (+)
3077 This variable selects what is propagated to the value of the
3078 status variable. For more information see the description of
3079 the status variable below.
3080 argv The arguments to the shell. Positional parameters are taken
3082 from argv, i.e., `$1' is replaced by `$argv[1]', etc. Set by
3083 default, but usually empty in interactive shells.
3084 autocorrect (+)
3086 If set, the spell-word editor command is invoked automatically
3087 before each completion attempt.
3088 autoexpand (+)
3090 If set, the expand-history editor command is invoked automati‐
3091 cally before each completion attempt. If this is set to only‐
3092 history, then only history will be expanded and a second com‐
3093 pletion will expand filenames.
3094 autolist (+)
3096 If set, possibilities are listed after an ambiguous completion.
3097 If set to `ambiguous', possibilities are listed only when no
3098 new characters are added by completion.
3099 autologout (+)
3101 The first word is the number of minutes of inactivity before
3102 automatic logout. The optional second word is the number of
3103 minutes of inactivity before automatic locking. When the shell
3104 automatically logs out, it prints `auto-logout', sets the vari‐
3105 able logout to `automatic' and exits. When the shell automati‐
3106 cally locks, the user is required to enter his password to con‐
3107 tinue working. Five incorrect attempts result in automatic
3108 logout. Set to `60' (automatic logout after 60 minutes, and no
3109 locking) by default in login and superuser shells, but not if
3110 the shell thinks it is running under a window system (i.e., the
3111 DISPLAY environment variable is set), the tty is a pseudo-tty
3112 (pty) or the shell was not so compiled (see the version shell
3113 variable). See also the afsuser and logout shell variables.
3114 autorehash (+)
3116 If set, the internal hash table of the contents of the directo‐
3117 ries in the path variable will be recomputed if a command is
3118 not found in the hash table. In addition, the list of avail‐
3119 able commands will be rebuilt for each command completion or
3120 spelling correction attempt if set to `complete' or `correct'
3121 respectively; if set to `always', this will be done for both
3122 cases.
3123 backslash_quote (+)
3125 If set, backslashes (`\') always quote `\', `'', and `"'. This
3126 may make complex quoting tasks easier, but it can cause syntax
3127 errors in csh(1) scripts.
3128 catalog The file name of the message catalog. If set, tcsh use
3130 `tcsh.${catalog}' as a message catalog instead of default
3131 `tcsh'.
3132 cdpath A list of directories in which cd should search for subdirecto‐
3134 ries if they aren't found in the current directory.
3135 cdtohome (+)
3137 If not set, cd requires a directory name, and will not go to
3138 the home directory if it's omitted. This is set by default.
3139 color If set, it enables color display for the builtin ls-F and it
3141 passes --color=auto to ls. Alternatively, it can be set to
3142 only ls-F or only ls to enable color to only one command. Set‐
3143 ting it to nothing is equivalent to setting it to (ls-F ls).
3144 colorcat
3146 If set, it enables color escape sequence for NLS message files.
3147 And display colorful NLS messages.
3148 command (+)
3150 If set, the command which was passed to the shell with the -c
3151 flag (q.v.).
3152 compat_expr (+)
3154 If set, the shell will evaluate expressions right to left, like
3155 the original csh.
3156 complete (+)
3158 If set to `igncase', the completion becomes case insensitive.
3159 If set to `enhance', completion ignores case and considers
3160 hyphens and underscores to be equivalent; it will also treat
3161 periods, hyphens and underscores (`.', `-' and `_') as word
3162 separators. If set to `Enhance', completion matches uppercase
3163 and underscore characters explicitly and matches lowercase and
3164 hyphens in a case-insensitive manner; it will treat periods,
3165 hyphens and underscores as word separators.
3166 continue (+)
3168 If set to a list of commands, the shell will continue the
3169 listed commands, instead of starting a new one.
3170 continue_args (+)
3172 Same as continue, but the shell will execute:
3173 echo `pwd` $argv > ~/.<cmd>_pause; %<cmd>
3175 correct (+)
3177 If set to `cmd', commands are automatically spelling-corrected.
3178 If set to `complete', commands are automatically completed. If
3179 set to `all', the entire command line is corrected.
3180 csubstnonl (+)
3182 If set, newlines and carriage returns in command substitution
3183 are replaced by spaces. Set by default.
3184 cwd The full pathname of the current directory. See also the
3186 dirstack and owd shell variables.
3187 dextract (+)
3189 If set, `pushd +n' extracts the nth directory from the direc‐
3190 tory stack rather than rotating it to the top.
3191 dirsfile (+)
3193 The default location in which `dirs -S' and `dirs -L' look for
3194 a history file. If unset, ~/.cshdirs is used. Because only
3195 ~/.tcshrc is normally sourced before ~/.cshdirs, dirsfile
3196 should be set in ~/.tcshrc rather than ~/.login.
3197 dirstack (+)
3199 An array of all the directories on the directory stack.
3200 `$dirstack[1]' is the current working directory, `$dirstack[2]'
3201 the first directory on the stack, etc. Note that the current
3202 working directory is `$dirstack[1]' but `=0' in directory stack
3203 substitutions, etc. One can change the stack arbitrarily by
3204 setting dirstack, but the first element (the current working
3205 directory) is always correct. See also the cwd and owd shell
3206 variables.
3207 dspmbyte (+)
3209 Has an effect iff 'dspm' is listed as part of the version shell
3210 variable. If set to `euc', it enables display and editing EUC-
3211 kanji(Japanese) code. If set to `sjis', it enables display and
3212 editing Shift-JIS(Japanese) code. If set to `big5', it enables
3213 display and editing Big5(Chinese) code. If set to `utf8', it
3214 enables display and editing Utf8(Unicode) code. If set to the
3215 following format, it enables display and editing of original
3216 multi-byte code format:
3217 > set dspmbyte = 0000....(256 bytes)....0000
3219 The table requires just 256 bytes. Each character of 256 char‐
3221 acters corresponds (from left to right) to the ASCII codes
3222 0x00, 0x01, ... 0xff. Each character is set to number 0,1,2
3223 and 3. Each number has the following meaning:
3224 0 ... not used for multi-byte characters.
3225 1 ... used for the first byte of a multi-byte character.
3226 2 ... used for the second byte of a multi-byte character.
3227 3 ... used for both the first byte and second byte of a
3228 multi-byte character.
3229 Example:
3231 If set to `001322', the first character (means 0x00 of the
3232 ASCII code) and second character (means 0x01 of ASCII code) are
3233 set to `0'. Then, it is not used for multi-byte characters.
3234 The 3rd character (0x02) is set to '1', indicating that it is
3235 used for the first byte of a multi-byte character. The 4th
3236 character(0x03) is set '3'. It is used for both the first byte
3237 and the second byte of a multi-byte character. The 5th and 6th
3238 characters (0x04,0x05) are set to '2', indicating that they are
3239 used for the second byte of a multi-byte character.
3240 The GNU fileutils version of ls cannot display multi-byte file‐
3242 names without the -N ( --literal ) option. If you are using
3243 this version, set the second word of dspmbyte to "ls". If not,
3244 for example, "ls-F -l" cannot display multi-byte filenames.
3245 Note:
3247 This variable can only be used if KANJI and DSPMBYTE has been
3248 defined at compile time.
3249 dunique (+)
3251 If set, pushd removes any instances of name from the stack
3252 before pushing it onto the stack.
3253 echo If set, each command with its arguments is echoed just before
3255 it is executed. For non-builtin commands all expansions occur
3256 before echoing. Builtin commands are echoed before command and
3257 filename substitution, because these substitutions are then
3258 done selectively. Set by the -x command line option.
3259 echo_style (+)
3261 The style of the echo builtin. May be set to
3262 bsd Don't echo a newline if the first argument is `-n'; the
3264 default for csh.
3265 sysv Recognize backslashed escape sequences in echo strings.
3266 both Recognize both the `-n' flag and backslashed escape
3267 sequences; the default for tcsh.
3268 none Recognize neither.
3269 Set by default to the local system default. The BSD and System
3271 V options are described in the echo(1) man pages on the appro‐
3272 priate systems.
3273 edit (+)
3275 If set, the command-line editor is used. Set by default in
3276 interactive shells.
3277 editors (+)
3279 A list of command names for the run-fg-editor editor command to
3280 match. If not set, the EDITOR (`ed' if unset) and VISUAL (`vi'
3281 if unset) environment variables will be used instead.
3282 ellipsis (+)
3284 If set, the `%c'/`%.' and `%C' prompt sequences (see the prompt
3285 shell variable) indicate skipped directories with an ellipsis
3286 (`...') instead of `/<skipped>'.
3287 euid (+)
3289 The user's effective user ID.
3290 euser (+)
3292 The first matching passwd entry name corresponding to the
3293 effective user ID.
3294 fignore (+)
3296 Lists file name suffixes to be ignored by completion.
3297 filec In tcsh, completion is always used and this variable is ignored
3299 by default. If edit is unset, then the traditional csh comple‐
3300 tion is used. If set in csh, filename completion is used.
3301 gid (+) The user's real group ID.
3303 globdot (+)
3305 If set, wild-card glob patterns will match files and directo‐
3306 ries beginning with `.' except for `.' and `..'
3307 globstar (+)
3309 If set, the `**' and `***' file glob patterns will match any
3310 string of characters including `/' traversing any existing sub-
3311 directories. (e.g. `ls **.c' will list all the .c files in
3312 the current directory tree). If used by itself, it will match
3313 zero or more sub-directories (e.g. `ls /usr/include/**/time.h'
3314 will list any file named `time.h' in the /usr/include directory
3315 tree; whereas `ls /usr/include/**time.h' will match any file in
3316 the /usr/include directory tree ending in `time.h'). To pre‐
3317 vent problems with recursion, the `**' glob-pattern will not
3318 descend into a symbolic link containing a directory. To over‐
3319 ride this, use `***'
3320 group (+)
3322 The user's group name.
3323 highlight
3325 If set, the incremental search match (in i-search-back and i-
3326 search-fwd) and the region between the mark and the cursor are
3327 highlighted in reverse video.
3328 Highlighting requires more frequent terminal writes, which
3330 introduces extra overhead. If you care about terminal perfor‐
3331 mance, you may want to leave this unset.
3332 histchars
3334 A string value determining the characters used in History sub‐
3335 stitution (q.v.). The first character of its value is used as
3336 the history substitution character, replacing the default char‐
3337 acter `!'. The second character of its value replaces the
3338 character `^' in quick substitutions.
3339 histdup (+)
3341 Controls handling of duplicate entries in the history list. If
3342 set to `all' only unique history events are entered in the his‐
3343 tory list. If set to `prev' and the last history event is the
3344 same as the current command, then the current command is not
3345 entered in the history. If set to `erase' and the same event
3346 is found in the history list, that old event gets erased and
3347 the current one gets inserted. Note that the `prev' and `all'
3348 options renumber history events so there are no gaps.
3349 histfile (+)
3351 The default location in which `history -S' and `history -L'
3352 look for a history file. If unset, ~/.history is used. hist‐
3353 file is useful when sharing the same home directory between
3354 different machines, or when saving separate histories on dif‐
3355 ferent terminals. Because only ~/.tcshrc is normally sourced
3356 before ~/.history, histfile should be set in ~/.tcshrc rather
3357 than ~/.login.
3358 histlit (+)
3360 If set, builtin and editor commands and the savehist mechanism
3361 use the literal (unexpanded) form of lines in the history list.
3362 See also the toggle-literal-history editor command.
3363 history The first word indicates the number of history events to save.
3365 The optional second word (+) indicates the format in which his‐
3366 tory is printed; if not given, `%h\t%T\t%R\n' is used. The
3367 format sequences are described below under prompt; note the
3368 variable meaning of `%R'. Set to `100' by default.
3369 home Initialized to the home directory of the invoker. The filename
3371 expansion of `~' refers to this variable.
3372 ignoreeof
3374 If set to the empty string or `0' and the input device is a
3375 terminal, the end-of-file command (usually generated by the
3376 user by typing `^D' on an empty line) causes the shell to print
3377 `Use "exit" to leave tcsh.' instead of exiting. This prevents
3378 the shell from accidentally being killed. Historically this
3379 setting exited after 26 successive EOF's to avoid infinite
3380 loops. If set to a number n, the shell ignores n - 1 consecu‐
3381 tive end-of-files and exits on the nth. (+) If unset, `1' is
3382 used, i.e., the shell exits on a single `^D'.
3383 implicitcd (+)
3385 If set, the shell treats a directory name typed as a command as
3386 though it were a request to change to that directory. If set
3387 to verbose, the change of directory is echoed to the standard
3388 output. This behavior is inhibited in non-interactive shell
3389 scripts, or for command strings with more than one word.
3390 Changing directory takes precedence over executing a like-named
3391 command, but it is done after alias substitutions. Tilde and
3392 variable expansions work as expected.
3393 inputmode (+)
3395 If set to `insert' or `overwrite', puts the editor into that
3396 input mode at the beginning of each line.
3397 killdup (+)
3399 Controls handling of duplicate entries in the kill ring. If
3400 set to `all' only unique strings are entered in the kill ring.
3401 If set to `prev' and the last killed string is the same as the
3402 current killed string, then the current string is not entered
3403 in the ring. If set to `erase' and the same string is found in
3404 the kill ring, the old string is erased and the current one is
3405 inserted.
3406 killring (+)
3408 Indicates the number of killed strings to keep in memory. Set
3409 to `30' by default. If unset or set to less than `2', the
3410 shell will only keep the most recently killed string. Strings
3411 are put in the killring by the editor commands that delete
3412 (kill) strings of text, e.g. backward-delete-word, kill-line,
3413 etc, as well as the copy-region-as-kill command. The yank edi‐
3414 tor command will yank the most recently killed string into the
3415 command-line, while yank-pop (see Editor commands) can be used
3416 to yank earlier killed strings.
3417 listflags (+)
3419 If set to `x', `a' or `A', or any combination thereof (e.g.,
3420 `xA'), they are used as flags to ls-F, making it act like `ls
3421 -xF', `ls -Fa', `ls -FA' or a combination (e.g., `ls -FxA'):
3422 `a' shows all files (even if they start with a `.'), `A' shows
3423 all files but `.' and `..', and `x' sorts across instead of
3424 down. If the second word of listflags is set, it is used as
3425 the path to `ls(1)'.
3426 listjobs (+)
3428 If set, all jobs are listed when a job is suspended. If set to
3429 `long', the listing is in long format.
3430 listlinks (+)
3432 If set, the ls-F builtin command shows the type of file to
3433 which each symbolic link points.
3434 listmax (+)
3436 The maximum number of items which the list-choices editor com‐
3437 mand will list without asking first.
3438 listmaxrows (+)
3440 The maximum number of rows of items which the list-choices edi‐
3441 tor command will list without asking first.
3442 loginsh (+)
3444 Set by the shell if it is a login shell. Setting or unsetting
3445 it within a shell has no effect. See also shlvl.
3446 logout (+)
3448 Set by the shell to `normal' before a normal logout, `auto‐
3449 matic' before an automatic logout, and `hangup' if the shell
3450 was killed by a hangup signal (see Signal handling). See also
3451 the autologout shell variable.
3452 mail A list of files and directories to check for incoming mail,
3454 optionally preceded by a numeric word. Before each prompt, if
3455 10 minutes have passed since the last check, the shell checks
3456 each file and says `You have new mail.' (or, if mail contains
3457 multiple files, `You have new mail in name.') if the filesize
3458 is greater than zero in size and has a modification time
3459 greater than its access time.
3460 If you are in a login shell, then no mail file is reported
3462 unless it has been modified after the time the shell has
3463 started up, to prevent redundant notifications. Most login
3464 programs will tell you whether or not you have mail when you
3465 log in.
3466 If a file specified in mail is a directory, the shell will
3468 count each file within that directory as a separate message,
3469 and will report `You have n mails.' or `You have n mails in
3470 name.' as appropriate. This functionality is provided primar‐
3471 ily for those systems which store mail in this manner, such as
3472 the Andrew Mail System.
3473 If the first word of mail is numeric it is taken as a different
3475 mail checking interval, in seconds.
3476 Under very rare circumstances, the shell may report `You have
3478 mail.' instead of `You have new mail.'
3479 matchbeep (+)
3481 If set to `never', completion never beeps. If set to
3482 `nomatch', it beeps only when there is no match. If set to
3483 `ambiguous', it beeps when there are multiple matches. If set
3484 to `notunique', it beeps when there is one exact and other
3485 longer matches. If unset, `ambiguous' is used.
3486 nobeep (+)
3488 If set, beeping is completely disabled. See also visiblebell.
3489 noclobber
3491 If set, restrictions are placed on output redirection to insure
3492 that files are not accidentally destroyed and that `>>' redi‐
3493 rections refer to existing files, as described in the
3494 Input/output section.
3495 noding If set, disable the printing of `DING!' in the prompt time
3497 specifiers at the change of hour.
3498 noglob If set, Filename substitution and Directory stack substitution
3500 (q.v.) are inhibited. This is most useful in shell scripts
3501 which do not deal with filenames, or after a list of filenames
3502 has been obtained and further expansions are not desirable.
3503 nokanji (+)
3505 If set and the shell supports Kanji (see the version shell
3506 variable), it is disabled so that the meta key can be used.
3507 nonomatch
3509 If set, a Filename substitution or Directory stack substitution
3510 (q.v.) which does not match any existing files is left
3511 untouched rather than causing an error. It is still an error
3512 for the substitution to be malformed, e.g., `echo [' still
3513 gives an error.
3514 nostat (+)
3516 A list of directories (or glob-patterns which match directo‐
3517 ries; see Filename substitution) that should not be stat(2)ed
3518 during a completion operation. This is usually used to exclude
3519 directories which take too much time to stat(2), for example
3520 /afs.
3521 notify If set, the shell announces job completions asynchronously.
3523 The default is to present job completions just before printing
3524 a prompt.
3525 oid (+) The user's real organization ID. (Domain/OS only)
3527 owd (+) The old working directory, equivalent to the `-' used by cd and
3529 pushd. See also the cwd and dirstack shell variables.
3530 padhour If set, enable the printing of padding '0' for hours, in 24 and
3532 12 hour formats. E.G.: 07:45:42 vs. 7:45:42.
3533 parseoctal
3535 To retain compatibily with older versions numeric variables
3536 starting with 0 are not interpreted as octal. Setting this
3537 variable enables proper octal parsing.
3538 path A list of directories in which to look for executable commands.
3540 A null word specifies the current directory. If there is no
3541 path variable then only full path names will execute. path is
3542 set by the shell at startup from the PATH environment variable
3543 or, if PATH does not exist, to a system-dependent default some‐
3544 thing like `(/usr/local/bin /usr/bsd /bin /usr/bin .)'. The
3545 shell may put `.' first or last in path or omit it entirely
3546 depending on how it was compiled; see the version shell vari‐
3547 able. A shell which is given neither the -c nor the -t option
3548 hashes the contents of the directories in path after reading
3549 ~/.tcshrc and each time path is reset. If one adds a new com‐
3550 mand to a directory in path while the shell is active, one may
3551 need to do a rehash for the shell to find it.
3552 printexitvalue (+)
3554 If set and an interactive program exits with a non-zero status,
3555 the shell prints `Exit status'.
3556 prompt The string which is printed before reading each command from
3558 the terminal. prompt may include any of the following format‐
3559 ting sequences (+), which are replaced by the given informa‐
3560 tion:
3561 %/ The current working directory.
3563 %~ The current working directory, but with one's home direc‐
3564 tory represented by `~' and other users' home directories
3565 represented by `~user' as per Filename substitution.
3566 `~user' substitution happens only if the shell has already
3567 used `~user' in a pathname in the current session.
3568 %c[[0]n], %.[[0]n]
3569 The trailing component of the current working directory, or
3570 n trailing components if a digit n is given. If n begins
3571 with `0', the number of skipped components precede the
3572 trailing component(s) in the format `/<skipped>trailing'.
3573 If the ellipsis shell variable is set, skipped components
3574 are represented by an ellipsis so the whole becomes
3575 `...trailing'. `~' substitution is done as in `%~' above,
3576 but the `~' component is ignored when counting trailing
3577 components.
3578 %C Like %c, but without `~' substitution.
3579 %h, %!, !
3580 The current history event number.
3581 %M The full hostname.
3582 %m The hostname up to the first `.'.
3583 %S (%s)
3584 Start (stop) standout mode.
3585 %B (%b)
3586 Start (stop) boldfacing mode.
3587 %U (%u)
3588 Start (stop) underline mode.
3589 %t, %@
3590 The time of day in 12-hour AM/PM format.
3591 %T Like `%t', but in 24-hour format (but see the ampm shell
3592 variable).
3593 %p The `precise' time of day in 12-hour AM/PM format, with
3594 seconds.
3595 %P Like `%p', but in 24-hour format (but see the ampm shell
3596 variable).
3597 \c c is parsed as in bindkey.
3598 ^c c is parsed as in bindkey.
3599 %% A single `%'.
3600 %n The user name.
3601 %N The effective user name.
3602 %j The number of jobs.
3603 %d The weekday in `Day' format.
3604 %D The day in `dd' format.
3605 %w The month in `Mon' format.
3606 %W The month in `mm' format.
3607 %y The year in `yy' format.
3608 %Y The year in `yyyy' format.
3609 %l The shell's tty.
3610 %L Clears from the end of the prompt to end of the display or
3611 the end of the line.
3612 %$ Expands the shell or environment variable name immediately
3613 after the `$'.
3614 %# `>' (or the first character of the promptchars shell vari‐
3615 able) for normal users, `#' (or the second character of
3616 promptchars) for the superuser.
3617 %{string%}
3618 Includes string as a literal escape sequence. It should be
3619 used only to change terminal attributes and should not move
3620 the cursor location. This cannot be the last sequence in
3621 prompt.
3622 %? The return code of the command executed just before the
3623 prompt.
3624 %R In prompt2, the status of the parser. In prompt3, the cor‐
3625 rected string. In history, the history string.
3626 `%B', `%S', `%U' and `%{string%}' are available in only eight-
3628 bit-clean shells; see the version shell variable.
3629 The bold, standout and underline sequences are often used to
3631 distinguish a superuser shell. For example,
3632 > set prompt = "%m [%h] %B[%@]%b [%/] you rang? "
3634 tut [37] [2:54pm] [/usr/accts/sys] you rang? _
3635 If `%t', `%@', `%T', `%p', or `%P' is used, and noding is not
3637 set, then print `DING!' on the change of hour (i.e, `:00' min‐
3638 utes) instead of the actual time.
3639 Set by default to `%# ' in interactive shells.
3641 prompt2 (+)
3643 The string with which to prompt in while and foreach loops and
3644 after lines ending in `\'. The same format sequences may be
3645 used as in prompt (q.v.); note the variable meaning of `%R'.
3646 Set by default to `%R? ' in interactive shells.
3647 prompt3 (+)
3649 The string with which to prompt when confirming automatic
3650 spelling correction. The same format sequences may be used as
3651 in prompt (q.v.); note the variable meaning of `%R'. Set by
3652 default to `CORRECT>%R (y|n|e|a)? ' in interactive shells.
3653 promptchars (+)
3655 If set (to a two-character string), the `%#' formatting
3656 sequence in the prompt shell variable is replaced with the
3657 first character for normal users and the second character for
3658 the superuser.
3659 pushdtohome (+)
3661 If set, pushd without arguments does `pushd ~', like cd.
3662 pushdsilent (+)
3664 If set, pushd and popd do not print the directory stack.
3665 recexact (+)
3667 If set, completion completes on an exact match even if a longer
3668 match is possible.
3669 recognize_only_executables (+)
3671 If set, command listing displays only files in the path that
3672 are executable. Slow.
3673 rmstar (+)
3675 If set, the user is prompted before `rm *' is executed.
3676 rprompt (+)
3678 The string to print on the right-hand side of the screen (after
3679 the command input) when the prompt is being displayed on the
3680 left. It recognizes the same formatting characters as prompt.
3681 It will automatically disappear and reappear as necessary, to
3682 ensure that command input isn't obscured, and will appear only
3683 if the prompt, command input, and itself will fit together on
3684 the first line. If edit isn't set, then rprompt will be
3685 printed after the prompt and before the command input.
3686 savedirs (+)
3688 If set, the shell does `dirs -S' before exiting. If the first
3689 word is set to a number, at most that many directory stack
3690 entries are saved.
3691 savehist
3693 If set, the shell does `history -S' before exiting. If the
3694 first word is set to a number, at most that many lines are
3695 saved. (The number should be less than or equal to the number
3696 history entries; if it is set to greater than the number of
3697 history settings, only history entries will be saved) If the
3698 second word is set to `merge', the history list is merged with
3699 the existing history file instead of replacing it (if there is
3700 one) and sorted by time stamp and the most recent events are
3701 retained. If the second word of savehist is `merge' and the
3702 third word is set to `lock', the history file update will be
3703 serialized with other shell sessions that would possibly like
3704 to merge history at exactly the same time. (+)
3705 sched (+)
3707 The format in which the sched builtin command prints scheduled
3708 events; if not given, `%h\t%T\t%R\n' is used. The format
3709 sequences are described above under prompt; note the variable
3710 meaning of `%R'.
3711 shell The file in which the shell resides. This is used in forking
3713 shells to interpret files which have execute bits set, but
3714 which are not executable by the system. (See the description
3715 of Builtin and non-builtin command execution.) Initialized to
3716 the (system-dependent) home of the shell.
3717 shlvl (+)
3719 The number of nested shells. Reset to 1 in login shells. See
3720 also loginsh.
3721 status The exit status from the last command or backquote expansion,
3723 or any command in a pipeline is propagated to status. (This is
3724 also the default csh behavior.) This default does not match
3725 what POSIX mandates (to return the status of the last command
3726 only). To match the POSIX behavior, you need to unset anyerror.
3727 If the anyerror variable is unset, the exit status of a pipe‐
3729 line is determined only from the last command in the pipeline,
3730 and the exit status of a backquote expansion is not propagated
3731 to status.
3732 If a command terminated abnormally, then 0200 is added to the
3734 status. Builtin commands which fail return exit status `1',
3735 all other builtin commands return status `0'.
3736 symlinks (+)
3738 Can be set to several different values to control symbolic link
3739 (`symlink') resolution:
3740 If set to `chase', whenever the current directory changes to a
3742 directory containing a symbolic link, it is expanded to the
3743 real name of the directory to which the link points. This does
3744 not work for the user's home directory; this is a bug.
3745 If set to `ignore', the shell tries to construct a current
3747 directory relative to the current directory before the link was
3748 crossed. This means that cding through a symbolic link and
3749 then `cd ..'ing returns one to the original directory. This
3750 affects only builtin commands and filename completion.
3751 If set to `expand', the shell tries to fix symbolic links by
3753 actually expanding arguments which look like path names. This
3754 affects any command, not just builtins. Unfortunately, this
3755 does not work for hard-to-recognize filenames, such as those
3756 embedded in command options. Expansion may be prevented by
3757 quoting. While this setting is usually the most convenient, it
3758 is sometimes misleading and sometimes confusing when it fails
3759 to recognize an argument which should be expanded. A compro‐
3760 mise is to use `ignore' and use the editor command normalize-
3761 path (bound by default to ^X-n) when necessary.
3762 Some examples are in order. First, let's set up some play
3764 directories:
3765 > cd /tmp
3767 > mkdir from from/src to
3768 > ln -s from/src to/dst
3769 Here's the behavior with symlinks unset,
3771 > cd /tmp/to/dst; echo $cwd
3773 /tmp/to/dst
3774 > cd ..; echo $cwd
3775 /tmp/from
3776 here's the behavior with symlinks set to `chase',
3778 > cd /tmp/to/dst; echo $cwd
3780 /tmp/from/src
3781 > cd ..; echo $cwd
3782 /tmp/from
3783 here's the behavior with symlinks set to `ignore',
3785 > cd /tmp/to/dst; echo $cwd
3787 /tmp/to/dst
3788 > cd ..; echo $cwd
3789 /tmp/to
3790 and here's the behavior with symlinks set to `expand'.
3792 > cd /tmp/to/dst; echo $cwd
3794 /tmp/to/dst
3795 > cd ..; echo $cwd
3796 /tmp/to
3797 > cd /tmp/to/dst; echo $cwd
3798 /tmp/to/dst
3799 > cd ".."; echo $cwd
3800 /tmp/from
3801 > /bin/echo ..
3802 /tmp/to
3803 > /bin/echo ".."
3804 ..
3805 Note that `expand' expansion 1) works just like `ignore' for
3807 builtins like cd, 2) is prevented by quoting, and 3) happens
3808 before filenames are passed to non-builtin commands.
3809 tcsh (+)
3811 The version number of the shell in the format `R.VV.PP', where
3812 `R' is the major release number, `VV' the current version and
3813 `PP' the patchlevel.
3814 term The terminal type. Usually set in ~/.login as described under
3816 Startup and shutdown.
3817 time If set to a number, then the time builtin (q.v.) executes auto‐
3819 matically after each command which takes more than that many
3820 CPU seconds. If there is a second word, it is used as a format
3821 string for the output of the time builtin. (u) The following
3822 sequences may be used in the format string:
3823 %U The time the process spent in user mode in cpu seconds.
3825 %S The time the process spent in kernel mode in cpu seconds.
3826 %E The elapsed (wall clock) time in seconds.
3827 %P The CPU percentage computed as (%U + %S) / %E.
3828 %W Number of times the process was swapped.
3829 %X The average amount in (shared) text space used in Kbytes.
3830 %D The average amount in (unshared) data/stack space used in
3831 Kbytes.
3832 %K The total space used (%X + %D) in Kbytes.
3833 %M The maximum memory the process had in use at any time in
3834 Kbytes.
3835 %F The number of major page faults (page needed to be brought
3836 from disk).
3837 %R The number of minor page faults.
3838 %I The number of input operations.
3839 %O The number of output operations.
3840 %r The number of socket messages received.
3841 %s The number of socket messages sent.
3842 %k The number of signals received.
3843 %w The number of voluntary context switches (waits).
3844 %c The number of involuntary context switches.
3845 Only the first four sequences are supported on systems without
3847 BSD resource limit functions. The default time format is `%Uu
3848 %Ss %E %P %X+%Dk %I+%Oio %Fpf+%Ww' for systems that support
3849 resource usage reporting and `%Uu %Ss %E %P' for systems that
3850 do not.
3851 Under Sequent's DYNIX/ptx, %X, %D, %K, %r and %s are not avail‐
3853 able, but the following additional sequences are:
3854 %Y The number of system calls performed.
3856 %Z The number of pages which are zero-filled on demand.
3857 %i The number of times a process's resident set size was
3858 increased by the kernel.
3859 %d The number of times a process's resident set size was
3860 decreased by the kernel.
3861 %l The number of read system calls performed.
3862 %m The number of write system calls performed.
3863 %p The number of reads from raw disk devices.
3864 %q The number of writes to raw disk devices.
3865 and the default time format is `%Uu %Ss %E %P %I+%Oio
3867 %Fpf+%Ww'. Note that the CPU percentage can be higher than
3868 100% on multi-processors.
3869 tperiod (+)
3871 The period, in minutes, between executions of the periodic spe‐
3872 cial alias.
3873 tty (+) The name of the tty, or empty if not attached to one.
3875 uid (+) The user's real user ID.
3877 user The user's login name.
3879 verbose If set, causes the words of each command to be printed, after
3881 history substitution (if any). Set by the -v command line
3882 option.
3883 version (+)
3885 The version ID stamp. It contains the shell's version number
3886 (see tcsh), origin, release date, vendor, operating system and
3887 machine (see VENDOR, OSTYPE and MACHTYPE) and a comma-separated
3888 list of options which were set at compile time. Options which
3889 are set by default in the distribution are noted.
3890 8b The shell is eight bit clean; default
3892 7b The shell is not eight bit clean
3893 wide The shell is multibyte encoding clean (like UTF-8)
3894 nls The system's NLS is used; default for systems with NLS
3895 lf Login shells execute /etc/csh.login before instead of
3896 after /etc/csh.cshrc and ~/.login before instead of after
3897 ~/.tcshrc and ~/.history.
3898 dl `.' is put last in path for security; default
3899 nd `.' is omitted from path for security
3900 vi vi(1)-style editing is the default rather than
3901 emacs(1)-style
3902 dtr Login shells drop DTR when exiting
3903 bye bye is a synonym for logout and log is an alternate name
3904 for watchlog
3905 al autologout is enabled; default
3906 kan Kanji is used if appropriate according to locale set‐
3907 tings, unless the nokanji shell variable is set
3908 sm The system's malloc(3) is used
3909 hb The `#!<program> <args>' convention is emulated when exe‐
3910 cuting shell scripts
3911 ng The newgrp builtin is available
3912 rh The shell attempts to set the REMOTEHOST environment
3913 variable
3914 afs The shell verifies your password with the kerberos server
3915 if local authentication fails. The afsuser shell vari‐
3916 able or the AFSUSER environment variable override your
3917 local username if set.
3918 An administrator may enter additional strings to indicate dif‐
3920 ferences in the local version.
3921 vimode (+)
3923 If unset, various key bindings change behavior to be more
3924 emacs(1)-style: word boundaries are determined by wordchars
3925 versus other characters.
3926 If set, various key bindings change behavior to be more
3928 vi(1)-style: word boundaries are determined by wordchars versus
3929 whitespace versus other characters; cursor behavior depends
3930 upon current vi mode (command, delete, insert, replace).
3931 This variable is unset by bindkey -e and set by bindkey -v.
3933 vimode may be explicitly set or unset by the user after those
3934 bindkey operations if required.
3935 visiblebell (+)
3937 If set, a screen flash is used rather than the audible bell.
3938 See also nobeep.
3939 watch (+)
3941 A list of user/terminal pairs to watch for logins and logouts.
3942 If either the user is `any' all terminals are watched for the
3943 given user and vice versa. Setting watch to `(any any)'
3944 watches all users and terminals. For example,
3945 set watch = (george ttyd1 any console $user any)
3947 reports activity of the user `george' on ttyd1, any user on the
3949 console, and oneself (or a trespasser) on any terminal.
3950 Logins and logouts are checked every 10 minutes by default, but
3952 the first word of watch can be set to a number to check every
3953 so many minutes. For example,
3954 set watch = (1 any any)
3956 reports any login/logout once every minute. For the impatient,
3958 the log builtin command triggers a watch report at any time.
3959 All current logins are reported (as with the log builtin) when
3960 watch is first set.
3961 The who shell variable controls the format of watch reports.
3963 who (+) The format string for watch messages. The following sequences
3965 are replaced by the given information:
3966 %n The name of the user who logged in/out.
3968 %a The observed action, i.e., `logged on', `logged off' or
3969 `replaced olduser on'.
3970 %l The terminal (tty) on which the user logged in/out.
3971 %M The full hostname of the remote host, or `local' if the
3972 login/logout was from the local host.
3973 %m The hostname of the remote host up to the first `.'. The
3974 full name is printed if it is an IP address or an X Window
3975 System display.
3976 %M and %m are available on only systems that store the remote
3978 hostname in /etc/utmp. If unset, `%n has %a %l from %m.' is
3979 used, or `%n has %a %l.' on systems which don't store the
3980 remote hostname.
3981 wordchars (+)
3983 A list of non-alphanumeric characters to be considered part of
3984 a word by the forward-word, backward-word etc., editor com‐
3985 mands. If unset, the default value is determined based on the
3986 state of vimode: if vimode is unset, `*?_-.[]~=' is used as the
3987 default; if vimode is set, `_' is used as the default.
3988
3990 AFSUSER (+)
3991 Equivalent to the afsuser shell variable.
3992 COLUMNS The number of columns in the terminal. See Terminal manage‐
3994 ment.
3995 DISPLAY Used by X Window System (see X(1)). If set, the shell does not
3997 set autologout (q.v.).
3998 EDITOR The pathname to a default editor. Used by the run-fg-editor
4000 editor command if the the editors shell variable is unset. See
4001 also the VISUAL environment variable.
4002 GROUP (+)
4004 Equivalent to the group shell variable.
4005 HOME Equivalent to the home shell variable.
4007 HOST (+)
4009 Initialized to the name of the machine on which the shell is
4010 running, as determined by the gethostname(2) system call.
4011 HOSTTYPE (+)
4013 Initialized to the type of machine on which the shell is run‐
4014 ning, as determined at compile time. This variable is obsolete
4015 and will be removed in a future version.
4016 HPATH (+)
4018 A colon-separated list of directories in which the run-help
4019 editor command looks for command documentation.
4020 LANG Gives the preferred character environment. See Native Language
4022 System support.
4023 LC_CTYPE
4025 If set, only ctype character handling is changed. See Native
4026 Language System support.
4027 LINES The number of lines in the terminal. See Terminal management.
4029 LS_COLORS
4031 The format of this variable is reminiscent of the termcap(5)
4032 file format; a colon-separated list of expressions of the form
4033 "xx=string", where "xx" is a two-character variable name. The
4034 variables with their associated defaults are:
4035 no 0 Normal (non-filename) text
4037 fi 0 Regular file
4038 di 01;34 Directory
4039 ln 01;36 Symbolic link
4040 pi 33 Named pipe (FIFO)
4041 so 01;35 Socket
4042 do 01;35 Door
4043 bd 01;33 Block device
4044 cd 01;32 Character device
4045 ex 01;32 Executable file
4046 mi (none) Missing file (defaults to fi)
4047 or (none) Orphaned symbolic link (defaults to ln)
4048 lc ^[[ Left code
4049 rc m Right code
4050 ec (none) End code (replaces lc+no+rc)
4051 You need to include only the variables you want to change from
4053 the default.
4054 File names can also be colorized based on filename extension.
4056 This is specified in the LS_COLORS variable using the syntax
4057 "*ext=string". For example, using ISO 6429 codes, to color all
4058 C-language source files blue you would specify "*.c=34". This
4059 would color all files ending in .c in blue (34) color.
4060 Control characters can be written either in C-style-escaped
4062 notation, or in stty-like ^-notation. The C-style notation
4063 adds ^[ for Escape, _ for a normal space character, and ? for
4064 Delete. In addition, the ^[ escape character can be used to
4065 override the default interpretation of ^[, ^, : and =.
4066 Each file will be written as <lc> <color-code> <rc> <filename>
4068 <ec>. If the <ec> code is undefined, the sequence <lc> <no>
4069 <rc> will be used instead. This is generally more convenient
4070 to use, but less general. The left, right and end codes are
4071 provided so you don't have to type common parts over and over
4072 again and to support weird terminals; you will generally not
4073 need to change them at all unless your terminal does not use
4074 ISO 6429 color sequences but a different system.
4075 If your terminal does use ISO 6429 color codes, you can compose
4077 the type codes (i.e., all except the lc, rc, and ec codes) from
4078 numerical commands separated by semicolons. The most common
4079 commands are:
4080 0 to restore default color
4082 1 for brighter colors
4083 4 for underlined text
4084 5 for flashing text
4085 30 for black foreground
4086 31 for red foreground
4087 32 for green foreground
4088 33 for yellow (or brown) foreground
4089 34 for blue foreground
4090 35 for purple foreground
4091 36 for cyan foreground
4092 37 for white (or gray) foreground
4093 40 for black background
4094 41 for red background
4095 42 for green background
4096 43 for yellow (or brown) background
4097 44 for blue background
4098 45 for purple background
4099 46 for cyan background
4100 47 for white (or gray) background
4101 Not all commands will work on all systems or display devices.
4103 A few terminal programs do not recognize the default end code
4105 properly. If all text gets colorized after you do a directory
4106 listing, try changing the no and fi codes from 0 to the numeri‐
4107 cal codes for your standard fore- and background colors.
4108 MACHTYPE (+)
4110 The machine type (microprocessor class or machine model), as
4111 determined at compile time.
4112 NOREBIND (+)
4114 If set, printable characters are not rebound to self-insert-
4115 command. See Native Language System support.
4116 OSTYPE (+)
4118 The operating system, as determined at compile time.
4119 PATH A colon-separated list of directories in which to look for exe‐
4121 cutables. Equivalent to the path shell variable, but in a dif‐
4122 ferent format.
4123 PWD (+) Equivalent to the cwd shell variable, but not synchronized to
4125 it; updated only after an actual directory change.
4126 REMOTEHOST (+)
4128 The host from which the user has logged in remotely, if this is
4129 the case and the shell is able to determine it. Set only if
4130 the shell was so compiled; see the version shell variable.
4131 SHLVL (+)
4133 Equivalent to the shlvl shell variable.
4134 SYSTYPE (+)
4136 The current system type. (Domain/OS only)
4137 TERM Equivalent to the term shell variable.
4139 TERMCAP The terminal capability string. See Terminal management.
4141 USER Equivalent to the user shell variable.
4143 VENDOR (+)
4145 The vendor, as determined at compile time.
4146 VISUAL The pathname to a default full-screen editor. Used by the run-
4148 fg-editor editor command if the the editors shell variable is
4149 unset. See also the EDITOR environment variable.
4150
4152 /etc/csh.cshrc Read first by every shell. ConvexOS, Stellix and Intel
4153 use /etc/cshrc and NeXTs use /etc/cshrc.std. A/UX,
4154 AMIX, Cray and IRIX have no equivalent in csh(1), but
4155 read this file in tcsh anyway. Solaris 2.x does not
4156 have it either, but tcsh reads /etc/.cshrc. (+)
4157 /etc/csh.login Read by login shells after /etc/csh.cshrc. ConvexOS,
4158 Stellix and Intel use /etc/login, NeXTs use
4159 /etc/login.std, Solaris 2.x uses /etc/.login and A/UX,
4160 AMIX, Cray and IRIX use /etc/cshrc.
4161 ~/.tcshrc (+) Read by every shell after /etc/csh.cshrc or its equiva‐
4162 lent.
4163 ~/.cshrc Read by every shell, if ~/.tcshrc doesn't exist, after
4164 /etc/csh.cshrc or its equivalent. This manual uses
4165 `~/.tcshrc' to mean `~/.tcshrc or, if ~/.tcshrc is not
4166 found, ~/.cshrc'.
4167 ~/.history Read by login shells after ~/.tcshrc if savehist is
4168 set, but see also histfile.
4169 ~/.login Read by login shells after ~/.tcshrc or ~/.history.
4170 The shell may be compiled to read ~/.login before
4171 instead of after ~/.tcshrc and ~/.history; see the ver‐
4172 sion shell variable.
4173 ~/.cshdirs (+) Read by login shells after ~/.login if savedirs is set,
4174 but see also dirsfile.
4175 /etc/csh.logout Read by login shells at logout. ConvexOS, Stellix and
4176 Intel use /etc/logout and NeXTs use /etc/logout.std.
4177 A/UX, AMIX, Cray and IRIX have no equivalent in csh(1),
4178 but read this file in tcsh anyway. Solaris 2.x does
4179 not have it either, but tcsh reads /etc/.logout. (+)
4180 ~/.logout Read by login shells at logout after /etc/csh.logout or
4181 its equivalent.
4182 /bin/sh Used to interpret shell scripts not starting with a
4183 `#'.
4184 /tmp/sh* Temporary file for `<<'.
4185 /etc/passwd Source of home directories for `~name' substitutions.
4186 The order in which startup files are read may differ if the shell was
4188 so compiled; see Startup and shutdown and the version shell variable.
4189
4191 This manual describes tcsh as a single entity, but experienced csh(1)
4192 users will want to pay special attention to tcsh's new features.
4193 A command-line editor, which supports emacs(1)-style or vi(1)-style key
4195 bindings. See The command-line editor and Editor commands.
4196 Programmable, interactive word completion and listing. See Completion
4198 and listing and the complete and uncomplete builtin commands.
4199 Spelling correction (q.v.) of filenames, commands and variables.
4201 Editor commands (q.v.) which perform other useful functions in the mid‐
4203 dle of typed commands, including documentation lookup (run-help), quick
4204 editor restarting (run-fg-editor) and command resolution (which-com‐
4205 mand).
4206 An enhanced history mechanism. Events in the history list are time-
4208 stamped. See also the history command and its associated shell vari‐
4209 ables, the previously undocumented `#' event specifier and new modi‐
4210 fiers under History substitution, the *-history, history-search-*, i-
4211 search-*, vi-search-* and toggle-literal-history editor commands and
4212 the histlit shell variable.
4213 Enhanced directory parsing and directory stack handling. See the cd,
4215 pushd, popd and dirs commands and their associated shell variables, the
4216 description of Directory stack substitution, the dirstack, owd and sym‐
4217 links shell variables and the normalize-command and normalize-path edi‐
4218 tor commands.
4219 Negation in glob-patterns. See Filename substitution.
4221 New File inquiry operators (q.v.) and a filetest builtin which uses
4223 them.
4224 A variety of Automatic, periodic and timed events (q.v.) including
4226 scheduled events, special aliases, automatic logout and terminal lock‐
4227 ing, command timing and watching for logins and logouts.
4228 Support for the Native Language System (see Native Language System sup‐
4230 port), OS variant features (see OS variant support and the echo_style
4231 shell variable) and system-dependent file locations (see FILES).
4232 Extensive terminal-management capabilities. See Terminal management.
4234 New builtin commands including builtins, hup, ls-F, newgrp, printenv,
4236 which and where (q.v.).
4237 New variables that make useful information easily available to the
4239 shell. See the gid, loginsh, oid, shlvl, tcsh, tty, uid and version
4240 shell variables and the HOST, REMOTEHOST, VENDOR, OSTYPE and MACHTYPE
4241 environment variables.
4242 A new syntax for including useful information in the prompt string (see
4244 prompt), and special prompts for loops and spelling correction (see
4245 prompt2 and prompt3).
4246 Read-only variables. See Variable substitution.
4248
4250 When a suspended command is restarted, the shell prints the directory
4251 it started in if this is different from the current directory. This
4252 can be misleading (i.e., wrong) as the job may have changed directories
4253 internally.
4254 Shell builtin functions are not stoppable/restartable. Command
4256 sequences of the form `a ; b ; c' are also not handled gracefully when
4257 stopping is attempted. If you suspend `b', the shell will then immedi‐
4258 ately execute `c'. This is especially noticeable if this expansion
4259 results from an alias. It suffices to place the sequence of commands
4260 in ()'s to force it to a subshell, i.e., `( a ; b ; c )'.
4261 Control over tty output after processes are started is primitive; per‐
4263 haps this will inspire someone to work on a good virtual terminal
4264 interface. In a virtual terminal interface much more interesting
4265 things could be done with output control.
4266 Alias substitution is most often used to clumsily simulate shell proce‐
4268 dures; shell procedures should be provided rather than aliases.
4269 Control structures should be parsed rather than being recognized as
4271 built-in commands. This would allow control commands to be placed any‐
4272 where, to be combined with `|', and to be used with `&' and `;' meta‐
4273 syntax.
4274 foreach doesn't ignore here documents when looking for its end.
4276 It should be possible to use the `:' modifiers on the output of command
4278 substitutions.
4279 The screen update for lines longer than the screen width is very poor
4281 if the terminal cannot move the cursor up (i.e., terminal type `dumb').
4282 HPATH and NOREBIND don't need to be environment variables.
4284 Glob-patterns which do not use `?', `*' or `[]' or which use `{}' or
4286 `~' are not negated correctly.
4287 The single-command form of if does output redirection even if the
4289 expression is false and the command is not executed.
4290 ls-F includes file identification characters when sorting filenames and
4292 does not handle control characters in filenames well. It cannot be
4293 interrupted.
4294 Command substitution supports multiple commands and conditions, but not
4296 cycles or backward gotos.
4297 Report bugs at https://bugs.astron.com/, preferably with fixes. If you
4299 want to help maintain and test tcsh, add yourself to the mailing list
4300 in https://mailman.astron.com/.
4301
4303 In 1964, DEC produced the PDP-6. The PDP-10 was a later re-implementa‐
4304 tion. It was re-christened the DECsystem-10 in 1970 or so when DEC
4305 brought out the second model, the KI10.
4306 TENEX was created at Bolt, Beranek & Newman (a Cambridge, Massachusetts
4308 think tank) in 1972 as an experiment in demand-paged virtual memory
4309 operating systems. They built a new pager for the DEC PDP-10 and cre‐
4310 ated the OS to go with it. It was extremely successful in academia.
4311 In 1975, DEC brought out a new model of the PDP-10, the KL10; they
4313 intended to have only a version of TENEX, which they had licensed from
4314 BBN, for the new box. They called their version TOPS-20 (their capi‐
4315 talization is trademarked). A lot of TOPS-10 users (`The OPerating
4316 System for PDP-10') objected; thus DEC found themselves supporting two
4317 incompatible systems on the same hardware--but then there were 6 on the
4318 PDP-11!
4319 TENEX, and TOPS-20 to version 3, had command completion via a user-
4321 code-level subroutine library called ULTCMD. With version 3, DEC moved
4322 all that capability and more into the monitor (`kernel' for you Unix
4323 types), accessed by the COMND% JSYS (`Jump to SYStem' instruction, the
4324 supervisor call mechanism [are my IBM roots also showing?]).
4325 The creator of tcsh was impressed by this feature and several others of
4327 TENEX and TOPS-20, and created a version of csh which mimicked them.
4328
4330 The system limits argument lists to ARG_MAX characters.
4331 The number of arguments to a command which involves filename expansion
4333 is limited to 1/6th the number of characters allowed in an argument
4334 list.
4335 Command substitutions may substitute no more characters than are
4337 allowed in an argument list.
4338 To detect looping, the shell restricts the number of alias substitu‐
4340 tions on a single line to 20.
4341
4343 csh(1), emacs(1), ls(1), newgrp(1), sh(1), setpath(1), stty(1), su(1),
4344 tset(1), vi(1), x(1), access(2), execve(2), fork(2), killpg(2),
4345 pipe(2), setrlimit(2), sigvec(2), stat(2), umask(2), vfork(2), wait(2),
4346 malloc(3), setlocale(3), tty(4), a.out(5), termcap(5), environ(7),
4347 termio(7), Introduction to the C Shell
4348
4350 This manual documents tcsh 6.22.02 (Astron) 2019-12-04.
4351
4353 William Joy
4354 Original author of csh(1)
4355 J.E. Kulp, IIASA, Laxenburg, Austria
4356 Job control and directory stack features
4357 Ken Greer, HP Labs, 1981
4358 File name completion
4359 Mike Ellis, Fairchild, 1983
4360 Command name recognition/completion
4361 Paul Placeway, Ohio State CIS Dept., 1983-1993
4362 Command line editor, prompt routines, new glob syntax and numerous
4363 fixes and speedups
4364 Karl Kleinpaste, CCI 1983-4
4365 Special aliases, directory stack extraction stuff, login/logout
4366 watch, scheduled events, and the idea of the new prompt format
4367 Rayan Zachariassen, University of Toronto, 1984
4368 ls-F and which builtins and numerous bug fixes, modifications and
4369 speedups
4370 Chris Kingsley, Caltech
4371 Fast storage allocator routines
4372 Chris Grevstad, TRW, 1987
4373 Incorporated 4.3BSD csh into tcsh
4374 Christos S. Zoulas, Cornell U. EE Dept., 1987-94
4375 Ports to HPUX, SVR2 and SVR3, a SysV version of getwd.c,
4376 SHORT_STRINGS support and a new version of sh.glob.c
4377 James J Dempsey, BBN, and Paul Placeway, OSU, 1988
4378 A/UX port
4379 Daniel Long, NNSC, 1988
4380 wordchars
4381 Patrick Wolfe, Kuck and Associates, Inc., 1988
4382 vi mode cleanup
4383 David C Lawrence, Rensselaer Polytechnic Institute, 1989
4384 autolist and ambiguous completion listing
4385 Alec Wolman, DEC, 1989
4386 Newlines in the prompt
4387 Matt Landau, BBN, 1989
4388 ~/.tcshrc
4389 Ray Moody, Purdue Physics, 1989
4390 Magic space bar history expansion
4391 Mordechai ????, Intel, 1989
4392 printprompt() fixes and additions
4393 Kazuhiro Honda, Dept. of Computer Science, Keio University, 1989
4394 Automatic spelling correction and prompt3
4395 Per Hedeland, Ellemtel, Sweden, 1990-
4396 Various bugfixes, improvements and manual updates
4397 Hans J. Albertsson (Sun Sweden)
4398 ampm, settc and telltc
4399 Michael Bloom
4400 Interrupt handling fixes
4401 Michael Fine, Digital Equipment Corp
4402 Extended key support
4403 Eric Schnoebelen, Convex, 1990
4404 Convex support, lots of csh bug fixes, save and restore of directory
4405 stack
4406 Ron Flax, Apple, 1990
4407 A/UX 2.0 (re)port
4408 Dan Oscarsson, LTH Sweden, 1990
4409 NLS support and simulated NLS support for non NLS sites, fixes
4410 Johan Widen, SICS Sweden, 1990
4411 shlvl, Mach support, correct-line, 8-bit printing
4412 Matt Day, Sanyo Icon, 1990
4413 POSIX termio support, SysV limit fixes
4414 Jaap Vermeulen, Sequent, 1990-91
4415 Vi mode fixes, expand-line, window change fixes, Symmetry port
4416 Martin Boyer, Institut de recherche d'Hydro-Quebec, 1991
4417 autolist beeping options, modified the history search to search for
4418 the whole string from the beginning of the line to the cursor.
4419 Scott Krotz, Motorola, 1991
4420 Minix port
4421 David Dawes, Sydney U. Australia, Physics Dept., 1991
4422 SVR4 job control fixes
4423 Jose Sousa, Interactive Systems Corp., 1991
4424 Extended vi fixes and vi delete command
4425 Marc Horowitz, MIT, 1991
4426 ANSIfication fixes, new exec hashing code, imake fixes, where
4427 Bruce Sterling Woodcock, sterling@netcom.com, 1991-1995
4428 ETA and Pyramid port, Makefile and lint fixes, ignoreeof=n addition,
4429 and various other portability changes and bug fixes
4430 Jeff Fink, 1992
4431 complete-word-fwd and complete-word-back
4432 Harry C. Pulley, 1992
4433 Coherent port
4434 Andy Phillips, Mullard Space Science Lab U.K., 1992
4435 VMS-POSIX port
4436 Beto Appleton, IBM Corp., 1992
4437 Walking process group fixes, csh bug fixes, POSIX file tests, POSIX
4438 SIGHUP
4439 Scott Bolte, Cray Computer Corp., 1992
4440 CSOS port
4441 Kaveh R. Ghazi, Rutgers University, 1992
4442 Tek, m88k, Titan and Masscomp ports and fixes. Added autoconf sup‐
4443 port.
4444 Mark Linderman, Cornell University, 1992
4445 OS/2 port
4446 Mika Liljeberg, liljeber@kruuna.Helsinki.FI, 1992
4447 Linux port
4448 Tim P. Starrin, NASA Langley Research Center Operations, 1993
4449 Read-only variables
4450 Dave Schweisguth, Yale University, 1993-4
4451 New man page and tcsh.man2html
4452 Larry Schwimmer, Stanford University, 1993
4453 AFS and HESIOD patches
4454 Luke Mewburn, RMIT University, 1994-6
4455 Enhanced directory printing in prompt, added ellipsis and rprompt.
4456 Edward Hutchins, Silicon Graphics Inc., 1996
4457 Added implicit cd.
4458 Martin Kraemer, 1997
4459 Ported to Siemens Nixdorf EBCDIC machine
4460 Amol Deshpande, Microsoft, 1997
4461 Ported to WIN32 (Windows/95 and Windows/NT); wrote all the missing
4462 library and message catalog code to interface to Windows.
4463 Taga Nayuta, 1998
4464 Color ls additions.
4465
4467 Bryan Dunlap, Clayton Elwell, Karl Kleinpaste, Bob Manson, Steve Romig,
4468 Diana Smetters, Bob Sutterfield, Mark Verber, Elizabeth Zwicky and all
4469 the other people at Ohio State for suggestions and encouragement
4470 All the people on the net, for putting up with, reporting bugs in, and
4472 suggesting new additions to each and every version
4473 Richard M. Alderson III, for writing the `T in tcsh' section
4475Astron 6.22.02 4 Dec 2019 TCSH(1)