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🐚 TCSH(1) - General Commands Manual

📖 NAME

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

🚀 Quick Reference

📌 Use Case	🖥️ Command	📝 Description
Start interactive shell	tcsh	Launch enhanced C shell
Execute script	tcsh script.csh	Run commands from file
Login shell	tcsh -l	Start as login shell
Read commands from stdin	tcsh -s	Interactive reading from stdin
Single command execution	tcsh -c "command"	Execute one command and exit
Debug script (parse only)	tcsh -n	Parse without executing
Echo commands before execution	tcsh -x	Set echo variable
Verbose mode (echo after history)	tcsh -v	Set verbose variable
Fast startup (no resource files)	tcsh -f	Skip ~/.tcshrc etc.
Force fork instead of vfork	tcsh -F	Use fork() for processes
List active jobs	jobs	Show background/suspended jobs
Bring job to foreground	fg %1	Resume job 1 in foreground
Send job to background	bg %1	Resume job 1 in background
Change directory	cd /path	Change working directory
Push directory onto stack	pushd /path	Change dir and push old one
Pop directory stack	popd	Return to previous directory
Show directory stack	dirs	List directory stack
Set environment variable	setenv VAR value	Set env var
Set shell variable	set var=value	Set shell variable
Unset variable	unset var	Remove shell variable
Define alias	alias name 'command'	Create command alias
Remove alias	unalias name	Delete alias
History list	history	Display command history
Repeat last command	!!	Re-execute previous command
Use last argument	!$	Insert last argument of previous command
Spelling correction	spell-word (M-s)	Correct current word
Complete word	Tab	Auto-complete filename/command/variable
List completion choices	^D	List possible completions
Edit command line	Emacs/Vi keys	Inline editing
Exit shell	exit or ^D	Terminate shell

📋 SYNOPSIS

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

🐚 DESCRIPTION

tcsh is an enhanced but completely compatible version of the Berkeley UNIX C shell, csh(1). It includes a command-line editor, programmable word completion, spelling correction, history mechanism, job control, and a C-like syntax. Features marked with (+) are not in most csh implementations; features marked with (u) are undocumented in csh.

🔹 Argument list processing

If the first argument is -, it's a login shell. A login shell can also be specified with -l as the only argument. The rest of the flag arguments are interpreted as follows:

• -b – Force break from option processing; remaining arguments are non-option.
• -c – Commands read from the following argument, stored in command shell variable.
• -d – Load directory stack from ~/.cshdirs.
• -Dname[=value] – Set environment variable name to value (Domain/OS only).
• -e – Exit if any command yields non-zero exit status.
• -f – Fast start: no resource files, no command hashing.
• -F – Use fork() instead of vfork().
• -i – Interactive shell even if not a terminal.
• -l – Login shell (only flag allowed).
• -m – Load ~/.tcshrc even if not effective user.
• -n – Parse commands but do not execute (debugging).
• -q – Accept SIGQUIT; job control disabled.
• -s – Read commands from standard input.
• -t – Read and execute a single line of input.
• -v – Set verbose variable; echo after history substitution.
• -x – Set echo variable; echo commands before execution.
• -V – Set verbose before executing ~/.tcshrc.
• -X – Like -x, but set before ~/.tcshrc.
• --help – Print help message and exit.
• --version – Print version/platform/compilation options.

After flag processing, if arguments remain and no -c, -i, -s, or -t was given, the first argument is taken as a script file. Remaining arguments are placed in argv.

🔹 Startup and shutdown

Login shells execute system files /etc/csh.cshrc and /etc/csh.login, then user files: ~/.tcshrc (or ~/.cshrc), ~/.history, ~/.login, and ~/.cshdirs. Non-login shells read only /etc/csh.cshrc and ~/.tcshrc/~/.cshrc. At logout, /etc/csh.logout and ~/.logout are executed.

🔹 Editing

The command-line editor is active when edit is set (default in interactive shells). bindkey displays/configures key bindings. Emacs-style bindings are default. Arrow keys are bound to down-history, up-history, backward-char, forward-char.

🔹 Completion and listing

Type part of a word and press Tab to complete. ^D lists possible completions. Completion works for filenames, commands, and variables. The complete builtin allows custom completions. Variables like autolist, recexact, fignore, autocorrect, autoexpand, recognize_only_executables affect behavior.

🔹 Spelling correction

Use M-s (spell-word) or M-$ (spell-line). Set correct to cmd or all for automatic correction. The shell prompts with corrected line; answer y/n/e/a.

🔹 Editor commands

Key bindings are listed by bindkey -l. Notable commands: complete-word (Tab), delete-char-or-list-or-eof (^D), expand-history (M-space), history-search-backward (M-p), i-search-back, vi-search-back, spell-word (M-s), run-help (M-h), which-command (M-?), yank-pop (M-y).

🔹 Lexical structure

Input lines are split at blanks, tabs, and special characters (&, |, ;, <, >, (, ), &&, ||, <<, >>). # starts a comment when input is not a terminal. Quoting with \, ', ", ` prevents special meaning.

🔹 Substitutions

📜 History substitution

History substitutions begin with !. Event specification: n (event number), -n (offset), # (current), ! (previous), s (beginning with string), ?s? (containing string). Word designators: 0 (command), n (argument), ^ (first), $ (last), * (all). Modifiers: h (head), t (tail), r (root), e (extension), u/l (case), s/l/r/ (substitute), & (repeat), g (global), a (apply to single word), p (print), q (quote), x (break into words).

📜 Alias substitution

After parsing, the first word of each command is checked for alias. Aliases can contain history references. Alias substitution is repeated until no change.

📜 Variable substitution

Variables are referenced with $name or ${name}. Subscripting: $name[selector]. Special variables: $0 (script name), $number (argv), $* (all args), $?name (set test), $#name (word count), $%name (character count), $$ (PID), $! (last background PID), $_ (last command line), $< (read from stdin). Modifiers from history can be applied.

📜 Command, filename and directory stack substitution

Command substitution: `command`. Filename substitution (globbing): *, ?, [...], {...}, ~ (home), ^ (negation). Directory stack substitution: =n expands to stack entry.

🔹 Commands

Simple commands, pipelines (|), sequences (;, ||, &&), and background execution (&). Parenthesized commands run in subshell.

🔹 Builtin and non-builtin command execution

Builtins execute within the shell. Non-builtins are searched via path and hashed. The shell emulates #! if compiled.

🔹 Input/output

Redirection: < file, << word, > file, >& file, >> file, >>& file. noclobber prevents overwriting. Diagnostic output can be piped with |&.

🔹 Features

📜 Control flow

foreach, switch, while, if-then-else. Keywords must appear on single input lines.

📜 Expressions

Logical, arithmetic, comparison operators: ||, &&, |, ^, &, ==, !=, =~, !~, <=, >=, <, >, <<, >>, +, -, *, /, %, !, ~, (, ). =~ and !~ match glob patterns.

📜 Command exit status

Commands in expressions return true (1) if exit status 0, false (0) otherwise.

📜 File inquiry operators

Test operators: -r, -w, -x, -X, -e, -o, -z, -s, -f, -d, -l, -b, -c, -p, -S, -u, -g, -k, -t, -R, -L. Information operators: -A, -A:, -M, -M:, -C, -C:, -D, -I, -F, -L (link target), -N, -P, -P:, -Pmode, -U, -U:, -G, -G:, -Z. Multiple operators can be combined.

📜 Jobs

Job control: bg, fg, stop, notify. Jobs referred by %job. Current job marked with +, previous with -.

📜 Status reporting

Shell notifies of job status changes before prompt. notify variable gives immediate notification.

📜 Automatic, periodic and timed events

sched for scheduled commands, beepcmd, cwdcmd, periodic, precmd, postcmd, jobcmd special aliases. autologout, mail, printexitvalue, rmstar, time, watch.

📜 Native Language System support

8-bit clean, supports character sets via LANG/LC_CTYPE. Printable characters in range \200-\377 are rebound to self-insert-command unless NOREBIND is set.

📜 OS variant support

Builtins for TCF, BS2000, Domain/OS, Mach, Masscomp/RTU, Harris CX/UX, Convex/OS. VENDOR, OSTYPE, MACHTYPE environment variables.

📜 Signal handling

Login shells ignore interrupts when reading ~/.logout. Quit ignored unless -q. Terminate caught by login shells. onintr, hup, nohup control handling.

📜 Terminal management

Three tty mode sets: edit, quote, execute. setty manages fixed modes. echotc, settc, telltc manipulate termcap. Window resizing adjusts LINES/COLUMNS.

📑 REFERENCE

🔹 Builtin commands

List of builtin commands with descriptions. Key entries:

• alias – Define/print aliases
• bg – Background jobs
• bindkey – Key bindings
• cd/chdir – Change directory
• complete – Programmable completions
• dirs – Directory stack
• echo – Print arguments
• eval – Execute arguments as shell input
• exec – Replace shell with command
• exit – Exit shell
• fg – Foreground jobs
• foreach – Loop over list
• glob – Filename expand
• goto – Jump to label
• history – Display/save history
• if – Conditional
• jobs – List jobs
• kill – Send signal
• limit – Set resource limits
• login/logout – Login/logout
• ls-F – List files with type indicators
• popd/pushd – Directory stack manipulation
• rehash – Recompute command hash table
• repeat – Repeat command
• sched – Scheduled events
• set/unset – Shell variables
• setenv/unsetenv – Environment variables
• shift – Shift argv
• source – Execute file
• stop – Stop background job
• suspend – Suspend shell
• switch – Multi-way branch
• time – Time command
• umask – File creation mask
• unalias – Remove alias
• unhash – Disable hashing
• unlimit – Remove resource limit
• wait – Wait for background jobs
• where – Locate command
• which – Show command path
• while – Loop

🔹 Special aliases

• beepcmd – Runs when bell rings
• cwdcmd – Runs after directory change
• jobcmd – Runs before/after command state change
• helpcommand – Invoked by run-help editor command
• periodic – Runs every tperiod minutes
• precmd – Runs before each prompt
• postcmd – Runs before each command
• shell – Interpreter for scripts without #!

🔹 Special shell variables

Essential variables:

• addsuffix – Add / or space after completion
• autolist – List completions on ambiguous
• autologout – Automatic logout/lock
• cdpath – Search path for cd
• correct – Automatic spelling correction
• cwd – Current working directory
• dirstack – Directory stack array
• echo – Echo commands before execution
• edit – Enable command-line editor
• fignore – Suffixes to ignore in completion
• gid/uid – Real user/group IDs
• histchars – History substitution characters
• histfile – History file location
• histlit – Use literal history
• history – Number of events to save
• home – Home directory
• ignoreeof – Ignore EOF to exit
• listjobs – List jobs on suspension
• loginsh – Set if login shell
• mail – Mail check files
• noclobber – Protect against overwriting
• noglob – Disable filename globbing
• nonomatch – Allow unmatched globs
• notify – Immediate job status notification
• path – Command search path
• prompt – Prompt string with format sequences
• savehist – Save history on exit
• shell – Shell executable path
• shlvl – Shell nesting level
• status – Exit status of last command
• symlinks – Symbolic link handling
• tcsh – Version number
• term – Terminal type
• time – Automatic timing threshold
• user – Login name
• version – Compilation options
• vimode – Vi-style editing mode
• visiblebell – Screen flash instead of beep
• watch – User/terminal watch list
• who – Format for watch messages
• wordchars – Word characters for editor

🌍 ENVIRONMENT

Environment variables: AFSUSER, COLUMNS, DISPLAY, EDITOR, GROUP, HOME, HOST, HOSTTYPE, HPATH, LANG, LC_CTYPE, LINES, LS_COLORS, MACHTYPE, NOREBIND, OSTYPE, PATH, PWD, REMOTEHOST, SHLVL, SYSTYPE, TERM, TERMCAP, USER, VENDOR, VISUAL. See descriptions in the manual for details.

📁 FILES

• /etc/csh.cshrc – Read first by every shell
• /etc/csh.login – Read by login shells
• ~/.tcshrc – Read by every shell (or ~/.cshrc)
• ~/.history – History file
• ~/.login – Login shell startup
• ~/.cshdirs – Directory stack file
• /etc/csh.logout – Read at logout
• ~/.logout – User logout script
• /bin/sh – Interpreter for scripts without #!
• /tmp/sh* – Temporary files for <<
• /etc/passwd – Home directory source for ~name

✨ NEW FEATURES

• Command-line editor (Emacs/Vi style)
• Programmable completion and listing
• Spelling correction
• Enhanced history (time-stamped, new modifiers)
• Directory stack enhancements
• Glob-pattern negation
• New file inquiry operators and filetest
• Automatic/periodic/timed events
• NLS and OS variant support
• Terminal management
• New builtins: builtins, hup, ls-F, newgrp, printenv, which, where
• New variables: gid, loginsh, oid, shlvl, tcsh, tty, uid, version
• Prompt format sequences
• Read-only variables

🐛 BUGS

• Suspended command restart may show wrong directory
• Builtin functions not stoppable/restartable
• Primitive tty output control
• Alias substitution clumsy
• Control structures should be parsed, not builtins
• foreach doesn't ignore here documents
• Modifiers on command substitutions not possible
• Screen update poor for long lines
• HPATH/NOREBIND shouldn't be env vars
• Glob negation broken for some patterns
• if does redirection even if false
• ls-F includes identification chars in sort
• Report bugs at https://bugs.astron.com/

🔤 THE T IN TCSH

tcsh is inspired by the TENEX/TOPS-20 command completion feature. The 't' stands for 'TENEX'.

⚠️ LIMITATIONS

• Argument list limited to ARG_MAX characters
• Filename expansion limited to 1/6th of argument list
• Command substitutions limited to argument list size
• Alias substitutions limited to 20 per line

📚 SEE ALSO

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

📌 VERSION

This manual documents tcsh 6.21.00 (Astron) 2019-05-08.

👤 AUTHORS

• William Joy – Original author of csh(1)
• J.E. Kulp – Job control and directory stack
• Ken Greer – File name completion
• Mike Ellis – Command name recognition/completion
• Paul Placeway – Command line editor, prompt routines, glob syntax
• Karl Kleinpaste – Special aliases, directory stack, login/logout watch, scheduled events
• Rayan Zachariassen – ls-F and which builtins
• Chris Kingsley – Fast storage allocator
• Chris Grevstad – Incorporated 4.3BSD csh into tcsh
• Christos S. Zoulas – Ports to many systems
• James J Dempsey, Paul Placeway – A/UX port
• Daniel Long – wordchars
• Patrick Wolfe – Vi mode cleanup
• David C Lawrence – autolist
• Alec Wolman – Newlines in prompt
• Matt Landau – ~/.tcshrc
• Ray Moody – Magic space bar
• Mordechai – printprompt() fixes
• Kazuhiro Honda – Spelling correction and prompt3
• Per Hedeland – Bugfixes and improvements
• Hans J. Albertsson – ampm, settc, telltc
• Michael Bloom – Interrupt handling
• Michael Fine – Extended key support
• Eric Schnoebelen – Convex support
• Ron Flax – A/UX 2.0 port
• Dan Oscarsson – NLS support
• Johan Widen – shlvl, Mach support, correct-line
• Matt Day – POSIX termio, SysV limit fixes
• Jaap Vermeulen – Vi mode fixes, expand-line
• Martin Boyer – autolist beeping options
• Scott Krotz – Minix port
• David Dawes – SVR4 job control
• Jose Sousa – Extended vi fixes
• Marc Horowitz – ANSIfication, exec hashing, where
• Bruce Sterling Woodcock – ETA, Pyramid, ignoreeof
• Jeff Fink – complete-word-fwd/back
• Harry C. Pulley – Coherent port
• Andy Phillips – VMS-POSIX
• Beto Appleton – Process group fixes, POSIX file tests
• Scott Bolte – CSOS port
• Kaveh R. Ghazi – Tek, m88k, Titan, Masscomp ports, autoconf
• Mark Linderman – OS/2 port
• Mika Liljeberg – Linux port
• Tim P. Starrin – Read-only variables
• Dave Schweisguth – Man page and tcsh.man2html
• Larry Schwimmer – AFS and HESIOD patches
• Luke Mewburn – Enhanced directory printing, ellipsis, rprompt
• Edward Hutchins – Implicit cd
• Martin Kraemer – EBCDIC port
• Amol Deshpande – WIN32 port
• Taga Nayuta – Color ls additions

🙏 THANKS TO

Bryan Dunlap, Clayton Elwell, Karl Kleinpaste, Bob Manson, Steve Romig, Diana Smetters, Bob Sutterfield, Mark Verber, Elizabeth Zwicky and all the other people at Ohio State for suggestions and encouragement. All the people on the net for bug reports and suggestions. Richard M. Alderson III for writing the 'T in tcsh' section.

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🐚 TCSH(1) - General Commands Manual 📖 NAME 🚀 Quick Reference 📋 SYNOPSIS 🐚 DESCRIPTION 📑 REFERENCE 🌍 ENVIRONMENT 📁 FILES ✨ NEW FEATURES 🐛 BUGS 🔤 THE T IN TCSH ⚠️ LIMITATIONS 📚 SEE ALSO 📌 VERSION 👤 AUTHORS 🙏 THANKS TO