## SYNOPSIS

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

## DESCRIPTION

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

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

           The rest of the flag arguments are interpreted as follows:

           -b  Forces a ``break'' from option processing, causing any
               further  shell  arguments  to be treated as non-option
               arguments.  The remaining arguments will not be inter
               preted  as  shell  options.   This may be used to pass
               options to a shell script without confusion or  possi
               ble  subterfuge.  The shell will not run a set-user ID
               script without this option.

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

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

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

           -e  The  shell  exits  if  any  invoked command terminates

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

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

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

           -s  Command input is taken from the standard input.

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

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

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

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

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

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

           Remaining arguments are placed in the argv shell variable.

       Startup and shutdown
           A login shell begins by executing commands from the system
           files /etc/csh.cshrc and /etc/csh.login.  It then executes
           commands  from  files  in the user's home directory: first
           ~/.tcshrc (+) or, if ~/.tcshrc  is  not  found,  ~/.cshrc,
           then  ~/.history (or the value of the histfile shell vari
           able), then ~/.login, and finally ~/.cshdirs (or the value
           of  the  dirsfile shell variable) (+).  The shell may read
           /etc/csh.login before instead of after /etc/csh.cshrc, and
           ~/.login before instead of after ~/.tcshrc or ~/.cshrc and
           specific commands, or can  have  both  a  ~/.cshrc  and  a
           ~/.tcshrc   which   sources   (see  the  builtin  command)
           ~/.cshrc.  The rest of this  manual  uses  `~/.tcshrc'  to
           mean  `~/.tcshrc or, if ~/.tcshrc is not found, ~/.cshrc'.

           In the normal case, the shell begins reading commands from
           the  terminal,  prompting with `> '.  (Processing of argu
           ments and the use of the shell to process files containing
           command  scripts  are described later.)  The shell repeat
           edly reads a line of command input, breaks it into  words,
           places  it on the command history list, parses it and exe
           cutes each command in the line.

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

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

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

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

           The shell always binds the arrow keys (as defined  in  the
           TERMCAP environment variable) to

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

           with any non-alphanumeric  characters  not  in  the  shell
           variable   wordchars,  while  the  shell  recognizes  only
           whitespace and some of the characters with  special  mean
           ings to it, listed under Lexical structure.

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

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

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

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

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

           word being completed.

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

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

           or

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

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

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

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

           The shell variable fignore can be set to a  list  of  suf
           fixes  to  be ignored by completion.  Consider the follow
           ing:

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

           the following files

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

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

               A_silly_file                         a-hyphenated-file
               another_silly_file

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

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

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

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

               > rm foo[tab]
               > rm foo

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

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

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

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

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

           Spelling  correction  recognizes  user-defined completions
           (see the complete builtin command).  If an input word in a
           position  for  which  a  completion is defined resembles a
           word in the completion list, spelling correction registers
           a  misspelling  and  suggests the latter word as a correc
           tion.  However, if the input word does not  match  any  of
           the  possible completions for that position, spelling cor
           rection does not register a misspelling.

           Like completion, spelling correction works anywhere in the
           line, pushing the rest of the line to the right and possi
           bly leaving extra characters to the right of the cursor.

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

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

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

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

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

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

           delete-char   (bound   to  `Del'  if  using  the  standard
           /etc/csh.cshrc)
                   Deletes  the character under the cursor.  See also
                   delete-char-or-list-or-eof.

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

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

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

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

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

           expand-history (M-space)
                   Expands  the  variable  to the left of the cursor.
                   See Variable substitution.

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

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

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

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

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

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

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

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

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

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

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

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

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

           run-help (M-h, M-H)
                   Searches for documentation on the current command,
                   using  the same notion of `current command' as the
                   completion routines, and prints it.  There  is  no
                   way to use a pager; run-help is designed for short
                   help files.  If the special alias  helpcommand  is
                   lines, but the inputmode shell variable can be set
                   to  `insert'  or  `overwrite' to put the editor in
                   that mode at the beginning of each line.  See also
                   overwrite-mode.

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

           spell-line (M-$)
                   Attempts to correct the spelling of each  word  in
                   the  input  buffer,  like  spell-word, but ignores
                   words whose first character is one  of  `-',  `!',
                   `^'  or  `%', or which contain `\', `*' or `?', to
                   avoid problems with  switches,  substitutions  and
                   the like.  See Spelling correction.

           spell-word (M-s, M-S)
                   Attempts  to  correct  the spelling of the current
                   word  as  described  under  Spelling   correction.
                   Checks  each  component of a word which appears to
                   be a pathname.

           toggle-literal-history (M-r, M-R)
                   Expands or `unexpands'  history  substitutions  in
                   the input buffer.  See also expand-history and the
                   autoexpand shell variable.

           undefined-key (any unbound key)
                   Beeps.

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

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

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

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

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

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

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

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

       Substitutions
           We now describe the various transformations the shell per
           Saved  commands  are  numbered  sequentially  from  1  and
           stamped with the time.  It is not usually necessary to use
           event numbers, but the current event number  can  be  made
           part  of  the prompt by placing an `!' in the prompt shell
           variable.

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

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

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

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

           A  history  substitution  may  have  an ``event specifica
           tion'', which indicates the event from which words are  to
           be  taken, a ``word designator'', which selects particular
           words from the chosen event, and/or a ``modifier'',  which
           manipulates the selected words.

           An event specification can be

               n       A number, referring to a particular event
               -n      An offset, referring to the event n before the
                       current event
               #       The current event.  This should be used  care
                       fully  in  csh(1), where there is no check for
                       recursion.  tcsh allows 10  levels  of  recur
                       sion.  (+)

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

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

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

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

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

           Selected  words  are  inserted into the command line sepa
           rated by single blanks.  For example, the  `diff'  command
           in  the  previous  example  might have been typed as `diff
           !!:1.old !!:1' (using `:1' to select  the  first  argument
           from  the  previous event) or `diff !-2:2 !-2:1' to select
           and swap the arguments  from  the  `cp'  command.   If  we

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

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

               h       Remove a trailing pathname component,  leaving
                       the head.
               t       Remove  all leading pathname components, leav
                       ing the tail.
               r       Remove a filename  extension  `.xxx',  leaving
                       the root name.
               e       Remove all but the extension.
               u       Uppercase the first lowercase letter.
               l       Lowercase the first uppercase letter.
               s/l/r/  Substitute l for r.  l is simply a string like
                       r, not a regular expression as in  the  epony
                       mous ed(1) command.  Any character may be used
                       as the delimiter in place of `/'; a `\' can be
                       used  to  quote  the delimiter inside l and r.
                       The character `&' in the r is replaced  by  l;
                       `\'  also  quotes  `&'.  If l is empty (``''),
                       the l from a previous substitution  or  the  s
                       from  a  previous `?s?' event specification is
                       used.  The trailing delimiter may  be  omitted
                       if it is immediately followed by a newline.
               &       Repeat the previous substitution.
               g       Apply  the  following  modifier  once  to each
                       word.
               a (+)   Apply the following modifier as many times  as
                       possible to a single word.  `a' and `g' can be
                       used together to apply  a  modifier  globally.
                       In  the  current implementation, using the `a'
                       and `s' modifiers  together  can  lead  to  an
                       infinite  loop.  For example, `:as/f/ff/' will
                       never terminate.  This behavior  might  change
                       in the future.
               p       Print  the new command line but do not execute
                       it.
               q       Quote the substituted words,  preventing  fur
                       ther substitutions.
               x       Like  q,  but break into words at blanks, tabs
                       and newlines.

           Modifiers are applied to only the  first  modifiable  word
           (unless  `g'  is  used).  It is an error for no word to be
           modifiable.
           make  the  spelling  correction  in  the previous example.
           This is the  only  history  substitution  which  does  not
           explicitly begin with `!'.

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

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

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

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

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

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

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

           Thus if the alias for `ls' were `ls -l'  the  command  `ls
           /usr'  would  become  `ls -l /usr', the argument list here
           aliases.

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

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

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

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

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

           Input/output  redirections  are recognized before variable
           expansion, and are variable expanded  separately.   Other
           wise,  the  command  name  and  entire  argument  list are
           expanded together.  It is  thus  possible  for  the  first
           (command)  word  (to this point) to generate more than one
           word, the first of which becomes the command name, and the
           is an error to reference a variable which is not set.

           $name
           ${name} Substitutes  the  words  of  the value of variable
                   name, each separated by a blank.  Braces  insulate
                   name  from following characters which would other
                   wise be part of it.  Shell  variables  have  names
                   consisting of up to 20 letters and digits starting
                   with a letter.  The underscore character  is  con
                   sidered  a  letter.   If name is not a shell vari
                   able, but is set in  the  environment,  then  that
                   value is returned (but `:' modifiers and the other
                   forms given below are not available in this case).
           $name[selector]
           ${name[selector]}
                   Substitutes only the selected words from the value
                   of name.  The selector is subjected to `$' substi
                   tution  and  may consist of a single number or two
                   numbers separated by a `-'.  The first word  of  a
                   variable's  value  is  numbered `1'.  If the first
                   number of a range is omitted it defaults  to  `1'.
                   If  the  last  member  of  a  range  is omitted it
                   defaults to `$#name'.  The  selector  `*'  selects
                   all  words.   It is not an error for a range to be
                   empty if the second  argument  is  omitted  or  in
                   range.
           $0      Substitutes  the  name of the file from which com
                   mand input is being read.  An error occurs if  the
                   name is not known.
           $number
           ${number}
                   Equivalent to `$argv[number]'.
           $*      Equivalent  to  `$argv',  which  is  equivalent to
                   `$argv[*]'.

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

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

           $?name
           ${?name}
                   Substitutes the string `1' if name is set, `0'  if
                   it is not.
           $?0     Substitutes  `1'  if the current input filename is
                   known, `0' if it is not.  Always `0'  in  interac
                   tive shells.

           $!      Substitutes the (decimal) process  number  of  the
                   last  background  process  started  by this shell.
                   (+)
           $_      Substitutes the command line of the  last  command
                   executed.  (+)
           $<      Substitutes  a  line from the standard input, with
                   no further interpretation thereafter.  It  can  be
                   used  to read from the keyboard in a shell script.
                   (+) While csh always quotes  $<,  as  if  it  were
                   equivalent to `$<:q', tcsh does not.  Furthermore,
                   when tcsh is waiting for a line to  be  typed  the
                   user  may  type  an  interrupt  to  interrupt  the
                   sequence into which the line is to be substituted,
                   but csh does not allow this.

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

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

       Command substitution
           Command substitution is indicated by a command enclosed in
           ``'.   The output from such a command is broken into sepa
           rate words at blanks, tabs and newlines,  and  null  words
           are discarded.  The output is variable and command substi
           tuted and put in place of the original string.

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

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

           In matching filenames, the character `.' at the  beginning

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

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

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

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

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

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

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

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

       Other substitutions (+)
           There are several  more  transformations  involving  file
           names,  not  strictly  related  to the above but mentioned
           here for completeness.  Any filename may be expanded to  a
           full  path  when  the  symlinks  variable (q.v.) is set to
           `expand'.  Quoting prevents this expansion, and  the  nor
           malize-path editor command does it on demand.  The normal
           ize-command editor command expands commands in  PATH  into
           full paths on demand.  Finally, cd and pushd interpret `-'
           as the old working  directory  (equivalent  to  the  shell
           variable  owd).  This is not a substitution at all, but an
           abbreviation recognized by only those commands.   Nonethe
           less, it too can be prevented by quoting.

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

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

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

           A  simple  command,  pipeline or sequence may be placed in
           parentheses, `()', to form a simple command, which may  in
           turn be a component of a pipeline or sequence.  A command,
           pipeline or sequence can be executed without  waiting  for
               cd; pwd

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

           When a command to be executed is found not to be a builtin
           command the shell attempts  to  execute  the  command  via
           execve(2).   Each word in the variable path names a direc
           tory in which the shell will look for the command.  If  it
           is  given  neither  a -c nor a -t option, the shell hashes
           the names in these directories into an internal  table  so
           that  it  will  try an execve(2) in only a directory where
           there is a possibility that  the  command  resides  there.
           This  greatly  speeds command location when a large number
           of directories are present in the search  path.   If  this
           mechanism  has  been turned off (via unhash), if the shell
           was given a -c or -t argument or  in  any  case  for  each
           directory  component  of  path which does not begin with a
           `/', the shell concatenates the current working  directory
           with  the given command name to form a path name of a file
           which it then attempts to execute.

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

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

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

           < name  Open  file  name (which is first variable, command
                   and filename expanded) as the standard input.
           << word Read the shell input up to a line which is identi
                   cal  to  word.  word is not subjected to variable,
                   filename or command substitution, and  each  input
                   line  is compared to word before any substitutions
                   are done on this input  line.   Unless  a  quoting
                   `\',  `"',  `' or ``' appears in word variable and
                   command substitution is performed on the interven

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

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

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

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

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

       Features
           Having described how the shell accepts,  parses  and  exe
           cutes  command lines, we now turn to a variety of its use
           ful features.

           input  whenever a loop is being read and performs seeks in
           this internal buffer to accomplish the  rereading  implied
           by  the  loop.   (To the extent that this allows, backward
           gotos will succeed on non-seekable inputs.)

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

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

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

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

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

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

       File inquiry operators
               f   Plain file
               d   Directory
               l   Symbolic link (+) *
               b   Block special file (+)
               c   Character special file (+)
               p   Named pipe (fifo) (+) *
               S   Socket special file (+) *
               u   Set-user-ID bit is set (+)
               g   Set-group-ID bit is set (+)
               k   Sticky bit is set (+)
               t   file (which must be  a  digit)  is  an  open  file
                   descriptor for a terminal device (+)
               R   Has been migrated (convex only) (+)
               L   Applies  subsequent operators in a multiple-opera
                   tor test to a symbolic link  rather  than  to  the
                   file to which the link points (+) *

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

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

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

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

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

               A       Last  file  access time, as the number of sec
                       onds since the epoch
               A:      Like A, but in timestamp  format,  e.g.,  `Fri
                       May 14 16:36:10 1993'
               M       Last file modification time
                       group  and  other,  `20' if by group only, and
                       `0' if by neither
               Pmode:  Like Pmode:, with leading zero
               U       Numeric userid
               U:      Username, or the numeric userid if  the  user
                       name is unknown
               G       Numeric groupid
               G:      Groupname,  or  the  numeric  groupid  if  the
                       groupname is unknown
               Z       Size, in bytes

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

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

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

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

               [1] 1234

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

           If you are running a job and wish to do something else you
           may hit the suspend key (usually `^Z'), which sends a STOP
           signal  to  the current job.  The shell will then normally
           indicate that the  job  has  been  `Suspended'  and  print
           another  prompt.   If  the listjobs shell variable is set,
           all jobs will be listed like the jobs builtin command;  if
           it  is  set  to `long' the listing will be in long format,
           like `jobs -l'.  You can then manipulate the state of  the
           suspended  job.  You can put it in the ``background'' with
           editing command.  (+)

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

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

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

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

       Status reporting
           The  shell  learns  immediately whenever a process changes
           state.  It normally informs you  whenever  a  job  becomes
           blocked  so that no further progress is possible, but only
           right before it prints a prompt.  This is done so that  it
           does  not  otherwise  disturb your work.  If, however, you
           set the shell variable notify, the shell will  notify  you
           immediately  of  changes  of  status  in  background jobs.
           There is also a shell command notify which marks a  single
           process  so  that  its  status changes will be immediately
           reported.  By default notify marks  the  current  process;
           simply  say  `notify'  after  starting a background job to
           mark it.

           When you try to leave the shell while  jobs  are  stopped,
           event list, to be executed by the shell at a given time.

           The beepcmd, cwdcmd, periodic, precmd, postcmd, and jobcmd
           Special  aliases can be set, respectively, to execute com
           mands when the shell wants to  ring  the  bell,  when  the
           working  directory  changes, every tperiod minutes, before
           each prompt, before each command gets executed, after each
           command  gets  executed,  and  when a job is started or is
           brought into the foreground.

           The autologout shell variable can be set  to  log  out  or
           lock the shell after a given number of minutes of inactiv
           ity.

           The mail shell variable can be set to check for  new  mail
           periodically.

           The  printexitvalue shell variable can be set to print the
           exit status of commands which exit  with  a  status  other
           than zero.

           The rmstar shell variable can be set to ask the user, when
           `rm *' is typed, if that is really what was meant.

           The time shell variable can be set  to  execute  the  time
           builtin  command  after the completion of any process that
           takes more than a given number of CPU seconds.

           The watch and who shell variables can  be  set  to  report
           when  selected  users  log  in or out, and the log builtin
           command reports on those users at any time.

       Native Language System support (+)
           The shell is eight bit clean (if so compiled; see the ver
           sion  shell  variable)  and  thus  supports character sets
           needing this capability.  NLS support differs depending on
           whether  or not the shell was compiled to use the system's
           NLS (again, see version).  In either case, 7-bit ASCII  is
           the  default  for  character  classification  (e.g., which
           characters are printable) and sorting,  and  changing  the
           LANG  or LC_CTYPE environment variables causes a check for
           possible changes in these respects.

           When using the system's NLS, the setlocale(3) function  is
           called  to  determine appropriate character classification
           and sorting.  This function typically  examines  the  LANG
           and  LC_CTYPE  environment  variables; refer to the system
           documentation for further details.   When  not  using  the
           system's  NLS, the shell simulates it by assuming that the
           ISO 8859-1 character set is used whenever  either  of  the
           LANG  and  LC_CTYPE variables are set, regardless of their
           values.  Sorting is not affected for the simulated NLS.
           nor  control  characters)  are printed in the format \nnn.
           If the tty is not in 8 bit mode, other  8  bit  characters
           are printed by converting them to ASCII and using standout
           mode.  The shell never changes the 7/8 bit mode of the tty
           and  tracks  user-initiated  changes of 7/8 bit mode.  NLS
           users (or, for that matter, those who want to use  a  meta
           key)  may  need  to  explicitly  set the tty in 8 bit mode
           through the appropriate  stty(1)  command  in,  e.g.,  the
           ~/.login file.

       OS variant support (+)
           A  number  of new builtin commands are provided to support
           features  in  particular  operating  systems.    All   are
           described in detail in the Builtin commands section.

           On   systems   that  support  TCF  (aix-ibm370,  aix-ps2),
           getspath and setspath get and  set  the  system  execution
           path,  getxvers  and setxvers get and set the experimental
           version prefix  and  migrate  migrates  processes  between
           sites.  The jobs builtin prints the site on which each job
           is executing.

           Under Domain/OS, inlib adds shared libraries to  the  cur
           rent  environment,  rootnode  changes the rootnode and ver
           changes the systype.

           Under Mach, setpath is equivalent to Mach's setpath(1).

           Under Masscomp/RTU and Harris  CX/UX,  universe  sets  the
           universe.

           Under  Harris  CX/UX,  ucb or att runs a command under the
           specified universe.

           Under Convex/OS, warp prints or sets the universe.

           The VENDOR,  OSTYPE  and  MACHTYPE  environment  variables
           indicate  respectively  the  vendor,  operating system and
           machine type (microprocessor class or  machine  model)  of
           the system on which the shell thinks it is running.  These
           are particularly useful when sharing one's home  directory
           between several types of machines; one can, for example,

               set  path = (~/bin.$MACHTYPE /usr/ucb /bin /usr/bin .)

           in one's ~/.login and put executables  compiled  for  each
           machine in the appropriate directory.

           The  version  shell  variable  indicates what options were
           chosen when the shell was compiled.

           Note also the newgrp builtin, the afsuser  and  echo_style

           The shell exits on a hangup (see  also  the  logout  shell
           variable).   By  default, the shell's children do too, but
           the shell does not send them a hangup when it exits.   hup
           arranges for the shell to send a hangup to a child when it
           exits, and nohup sets a child to ignore hangups.

       Terminal management (+)
           The shell uses three different sets of terminal  (``tty'')
           modes: `edit', used when editing, `quote', used when quot
           ing literal characters, and `execute', used when executing
           commands.  The shell holds some settings in each mode con
           stant, so commands which leave the tty in a confused state
           do  not  interfere with the shell.  The shell also matches
           changes in the speed and padding of the tty.  The list  of
           tty modes that are kept constant can be examined and modi
           fied with the setty builtin.  Note that although the  edi
           tor  uses CBREAK mode (or its equivalent), it takes typed-
           ahead characters anyway.

           The echotc, settc and  telltc  commands  can  be  used  to
           manipulate  and  debug terminal capabilities from the com
           mand line.

           On systems that support SIGWINCH or SIGWINDOW,  the  shell
           adapts  to  window  resizing automatically and adjusts the
           environment variables LINES and COLUMNS if  set.   If  the
           environment  variable TERMCAP contains li# and co# fields,
           the shell adjusts them to reflect the new window size.

## REFERENCE

           The next sections of  this  manual  describe  all  of  the
           available  Builtin  commands,  Special aliases and Special
           shell variables.

       Builtin commands
           %job    A synonym for the fg builtin command.

           %job &  A synonym for the bg builtin command.

           :       Does nothing, successfully.

           @
           @ name = expr
           @ name[index] = expr
           @ name++|--
           @ name[index]++|--
                   The first form prints  the  values  of  all  shell
                   variables.

                   The second form assigns the value of expr to name.
                   The third form assigns the value of  expr  to  the
                   expr  are  optional.   Components  of expr must be
                   separated by spaces.

           alias [name [wordlist]]
                   Without arguments, prints all aliases.  With name,
                   prints   the   alias  for  name.   With  name  and
                   wordlist, assigns wordlist as the alias  of  name.
                   wordlist  is  command  and  filename  substituted.
                   name may not be `alias' or  `unalias'.   See  also
                   the unalias builtin command.

           alloc   Shows  the amount of dynamic memory acquired, bro
                   ken down into used and free memory.  With an argu
                   ment  shows  the number of free and used blocks in
                   each size category.  The categories start at  size
                   8  and double at each step.  This command's output
                   may vary  across  system  types,  because  systems
                   other  than  the  VAX  may  use a different memory
                   allocator.

           bg [%job ...]
                   Puts the specified jobs  (or,  without  arguments,
                   the  current  job) into the background, continuing
                   each if it is stopped.  job may  be  a  number,  a
                   string,  `',  `%',  `+'  or `-' as described under
                   Jobs.

           bindkey [-l|-d|-e|-v|-u] (+)
           bindkey [-a] [-b] [-k] [-r] [--] key (+)
           bindkey [-a] [-b] [-k] [-c|-s] [--] key command (+)
                   Without options, the first form  lists  all  bound
                   keys  and  the  editor  command  to  which each is
                   bound, the second form lists the editor command to
                   which  key  is  bound and the third form binds the
                   editor command command to key.  Options include:

                   -l  Lists all editor commands and a short descrip
                       tion of each.
                   -d  Binds  all  keys  to the standard bindings for
                       the default editor.
                   -e  Binds all keys to the standard GNU  Emacs-like
                       bindings.
                   -v  Binds  all  keys  to  the  standard vi(1)-like
                       bindings.
                   -a  Lists or changes key-bindings in the  alterna
                       tive  key map.  This is the key map used in vi
                       command mode.
                   -b  key is  interpreted  as  a  control  character
                       written ^character (e.g., `^A') or C-character
                       (e.g., `C-A'), a  meta  character  written  M-
                       character  (e.g., `M-A'), a function key writ
                       ten  F-string  (e.g.,   `F-string'),   or   an
                       interpretation.
                   --  Forces  a break from option processing, so the
                       next word is taken as key even  if  it  begins
                       with '-'.
                   -u (or any invalid option)
                       Prints a usage message.

                   key  may  be a single character or a string.  If a
                   command is bound to a string, the first  character
                   of the string is bound to sequence-lead-in and the
                   entire string is bound to the command.

                   Control characters in key can be literal (they can
                   be typed by preceding them with the editor command
                   quoted-insert, normally bound to `^V') or  written
                   caret-character  style,  e.g.,  `^A'.   Delete  is
                   written `^?'  (caret-question mark).  key and com
                   mand  can contain backslashed escape sequences (in
                   the style of System V echo(1)) as follows:

                       \a      Bell
                       \b      Backspace
                       \e      Escape
                       \f      Form feed
                       \n      Newline
                       \r      Carriage return
                       \t      Horizontal tab
                       \v      Vertical tab
                       \nnn    The ASCII character  corresponding  to
                               the octal number nnn

                   `\' nullifies the special meaning of the following
                   character, if it has any, notably `\' and `^'.

           break   Causes execution to resume after the  end  of  the
                   nearest enclosing foreach or while.  The remaining
                   commands on the current line are executed.  Multi-
                   level breaks are thus possible by writing them all
                   on one line.

           breaksw Causes a break from a switch, resuming  after  the
                   endsw.

           builtins (+)
                   Prints the names of all builtin commands.

           bye (+) A  synonym for the logout builtin command.  Avail
                   able only if the shell was so  compiled;  see  the
                   version shell variable.

           case label:
                   A  label in a switch statement as discussed below.
                   With -p, prints the final  directory  stack,  just
                   like  dirs.  The -l, -n and -v flags have the same
                   effect on cd as on dirs, and they imply -p.  (+)

                   See also the implicitcd shell variable.

           chdir   A synonym for the cd builtin command.

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

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

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

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

                   list, the list of possible completions, may be one
                   of the following:

                       a       Aliases
                       b       Bindings (editor commands)
                       c       Commands  (builtin  or  external  com
                               mands)
                       C       External commands which begin with the
                               supplied path prefix
                       d       Directories
                       D       Directories  which begin with the sup
                               plied path prefix

                       u       Usernames
                       x       Like n, but prints select  when  list-
                               choices is used.
                       X       Completions
                       $var    Words from the variable var
                       (...)   Words from the given list
                       `...`   Words from the output of command

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

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

                   Now for some examples.  Some  commands  take  only
                   directories as arguments, so there's no point com
                   pleting plain files.

                       > complete cd 'p/1/d/'

                   completes  only  the  first  word  following  `cd'
                   (`p/1')  with  a directory.  p-type completion can
                   also be used to narrow down command completion:

                       > co[^D]
                       complete compress
                       > complete -co* 'p/0/(compress)/'
                       > co[^D]
                       > compress

                   This completion completes commands (words in posi
                   tion  0, `p/0') which begin with `co' (thus match
                   ing `co*') to `compress' (the  only  word  in  the
                   list).   The  leading `-' indicates that this com
                   pletion is to be used  with  only  ambiguous  com
                   mands.

                       > complete find 'n/-user/u/'

                   is an example of n-type completion.  Any word fol
                   lowing `find' and immediately following `-user' is
                   completed from the list of users.

                   These  complete  words  following   `alias'   with
                   aliases, `man' with commands, and `set' with shell
                   variables.  `true' doesn't have any options, so  x
                   does  nothing  when  completion  is  attempted and
                   prints `Truth has  no  options.'  when  completion
                   choices are listed.

                   Note that the man example, and several other exam
                   ples below, could just as well have used 'c/*'  or
                   'n/*' as 'p/*'.

                   Words  can  be completed from a variable evaluated
                   at completion time,

                       > complete ftp 'p/1/$hostnames/'
                       > set hostnames = (rtfm.mit.edu  tesla.ee.cor
                       nell.edu)
                       > ftp [^D]
                       rtfm.mit.edu tesla.ee.cornell.edu
                       > ftp [^C]
                       >  set hostnames = (rtfm.mit.edu tesla.ee.cor
                       nell.edu uunet.uu.net)
                       > ftp [^D]
                       rtfm.mit.edu tesla.ee.cornell.edu uunet.uu.net

                   or from a command run at completion time:

                       >   complete  kill  'p/*/`ps  |  awk  \{print\
                       \$1\}`/'
                       > kill -9 [^D]
                       23113 23377 23380 23406 23429 23529 23530 PID

                   Note that the complete  command  does  not  itself
                   quote  its arguments, so the braces, space and `$'
                   in `{print $1}' must be quoted explicitly.

                   One command can have multiple completions:

                       > complete dbx 'p/2/(core)/' 'p/*/c/'

                   completes the second argument to  `dbx'  with  the
                   word `core' and all other arguments with commands.
                   Note that the positional completion  is  specified
                   before  the next-word completion.  Because comple
                   tions are evaluated from left  to  right,  if  the
                   next-word completion were specified first it would
                   always match and the positional  completion  would
                   never  be executed.  This is a common mistake when
                   defining a completion.

                   The select pattern is useful when a command  takes
                   to  exclude precious source code from `rm' comple
                   tion.  Of course, one could  still  type  excluded
                   names  manually  or override the completion mecha
                   nism using the complete-word-raw or  list-choices-
                   raw editor commands (q.v.).

                   The `C', `D', `F' and `T' lists are like `c', `d',
                   `f' and `t' respectively, but they use the  select
                   argument  in  a different way: to restrict comple
                   tion to files beginning  with  a  particular  path
                   prefix.   For  example,  the Elm mail program uses
                   `=' as an abbreviation for one's  mail  directory.
                   One might use

                       > complete elm c@=@F:$HOME/Mail/@

                   to  complete  `elm  -f  ='  as  if it were `elm -f
                   ~/Mail/'.  Note that we used `@' instead of `/' to
                   avoid  confusion  with the select argument, and we
                   used `$HOME' instead of `~' because home directory
                   substitution  works  at  only  the  beginning of a
                   word.

                   suffix is used to add a  nonstandard  suffix  (not
                   space  or `/' for directories) to completed words.

                       > complete finger 'c/*@/$hostnames/' 'p/1/u/@'

                   completes  arguments  to `finger' from the list of
                   users, appends an `@', and  then  completes  after
                   the `@' from the `hostnames' variable.  Note again
                   the order in which the completions are  specified.

                   Finally, here's a complex example for inspiration:

                       > complete find \
                       ´n/-name/f/' 'n/-newer/f/' 'n/-{,n}cpio/f/' \
                       ´n/-exec/c/' 'n/-ok/c/' 'n/-user/u/' \
                       ´n/-group/g/' 'n/-fstype/(nfs 4.2)/' \
                       ´n/-type/(b c d f l p s)/' \
                       ´c/-/(name newer cpio ncpio exec ok user \
                       group fstype type atime ctime depth inum \
                       ls mtime nogroup nouser perm print prune \
                       size xdev)/' \
                       ´p/*/d/'

                   This completes words following `-name',  `-newer',
                   `-cpio' or `ncpio' (note the pattern which matches
                   both) to files, words following `-exec'  or  `-ok'
                   to commands, words following `user' and `group' to
                   users and groups respectively and words  following
                   `-fstype'  or  `-type'  to  members  of  the given
                   Continues execution of the nearest enclosing while
                   or foreach.  The rest of the commands on the  cur
                   rent line are executed.

           default:
                   Labels the default case in a switch statement.  It
                   should come after all case labels.

           dirs [-l] [-n|-v]
           dirs -S|-L [filename] (+)
           dirs -c (+)
                   The first form prints the  directory  stack.   The
                   top  of  the  stack  is  at the left and the first
                   directory in the stack is the  current  directory.
                   With  -l, `~' or `~name' in the output is expanded
                   explicitly to home or the  pathname  of  the  home
                   directory for user name.  (+) With -n, entries are
                   wrapped before they reach the edge of the  screen.
                   (+)  With  -v,  entries  are printed one per line,
                   preceded by their stack positions.   (+)  If  more
                   than  one  of  -n  or -v is given, -v takes prece
                   dence.  -p is accepted but does nothing.

                   With -S, the second form saves the directory stack
                   to  filename as a series of cd and pushd commands.
                   With -L, the shell sources filename, which is pre
                   sumably  a  directory  stack  file saved by the -S
                   option or the savedirs mechanism.  In either case,
                   dirsfile  is  used  if  filename  is not given and
                   ~/.cshdirs is used if dirsfile is unset.

                   Note that login shells do the equivalent of  `dirs
                   -L'  on startup and, if savedirs is set, `dirs -S'
                   before exiting.  Because only  ~/.tcshrc  is  nor
                   mally  sourced  before ~/.cshdirs, dirsfile should
                   be set in ~/.tcshrc rather than ~/.login.

                   The last form clears the directory stack.

           echo [-n] word ...
                   Writes each word to the shell's  standard  output,
                   separated by spaces and terminated with a newline.
                   The echo_style shell variable may be set  to  emu
                   late  (or  not)  the flags and escape sequences of
                   the BSD and/or System  V  versions  of  echo;  see
                   echo(1).

           echotc [-sv] arg ... (+)
                   Exercises  the  terminal  capabilities  (see term
                   cap(5)) in args.  For example, 'echotc home' sends
                   the  cursor to the home position, 'echotc cm 3 10'
                   sends it to column 3 and row 10, and 'echotc ts 0;
                   Termcap strings may contain wildcards  which  will
                   not  echo correctly.  One should use double quotes
                   when setting a shell variable to a terminal  capa
                   bility  string,  as  in the following example that
                   places the date in the status line:

                       > set tosl="`echotc ts 0`"
                       > set frsl="`echotc fs`"
                       > echo -n "$tosl";date; echo -n "$frsl"

                   With -s, nonexistent capabilities return the empty
                   string  rather  than  causing  an error.  With -v,
                   messages are verbose.

           else
           end
           endif
           endsw   See the description of the  foreach,  if,  switch,
                   and while statements below.

           eval arg ...
                   Treats  the  arguments  as  input to the shell and
                   executes the resulting command(s) in  the  context
                   of  the  current  shell.   This is usually used to
                   execute commands generated as the result  of  com
                   mand  or  variable  substitution,  because parsing
                   occurs before these  substitutions.   See  tset(1)
                   for a sample use of eval.

           exec command
                   Executes  the  specified  command  in place of the
                   current shell.

           exit [expr]
                   The shell exits either with the value of the spec
                   ified  expr  (an  expression,  as  described under
                   Expressions) or, without expr, with the  value  of
                   the status variable.

           fg [%job ...]
                   Brings  the specified jobs (or, without arguments,
                   the current job) into the  foreground,  continuing
                   each  if  it  is  stopped.  job may be a number, a
                   string, `', `%', `+' or  `-'  as  described  under
                   Jobs.   See also the run-fg-editor editor command.

           filetest -op file ... (+)
                   Applies op (which is a file  inquiry  operator  as
                   described  under  File  inquiry operators) to each
                   file and returns the results as a  space-separated
                   list.

           getspath (+)
                   Prints the system execution path.  (TCF only)

           getxvers (+)
                   Prints  the  experimental  version  prefix.   (TCF
                   only)

           glob wordlist
                   Like  echo,  but no `\' escapes are recognized and
                   words are delimited by null characters in the out
                   put.   Useful  for  programs which wish to use the
                   shell to filename expand a list of words.

           goto word
                   word is filename and command-substituted to  yield
                   a  string  of the form `label'.  The shell rewinds
                   its input as much as possible, searches for a line
                   of  the form `label:', possibly preceded by blanks
                   or tabs, and continues execution after that  line.

           hashstat
                   Prints  a statistics line indicating how effective
                   the internal hash table has been at locating  com
                   mands (and avoiding exec's).  An exec is attempted
                   for each component of  the  path  where  the  hash
                   function  indicates  a  possible  hit, and in each
                   component which does not begin with a `/'.

                   On machines without vfork(2), prints only the num
                   ber and size of hash buckets.

           history [-hTr] [n]
           history -S|-L|-M [filename] (+)
           history -c (+)
                   The  first form prints the history event list.  If
                   n is given only  the  n  most  recent  events  are
                   printed  or  saved.   With -h, the history list is
                   printed without leading numbers.  If -T is  speci
                   fied, timestamps are printed also in comment form.
                   (This can be used to produce  files  suitable  for
                   loading  with  'history -L' or 'source -h'.)  With
                   -r, the order of printing  is  most  recent  first
                   rather than oldest first.

                   With -S, the second form saves the history list to
                   filename.  If the first word of the savehist shell
                   variable  is  set  to  a number, at most that many
                   lines are saved.  If the second word  of  savehist
                   is set to `merge', the history list is merged with
                   the existing history file instead of replacing  it
                   (if  there  is one) and sorted by time stamp.  (+)
                   filename.

                   Note that login shells do the equivalent of  `his
                   tory -L' on startup and, if savehist is set, `his
                   tory -S' before exiting.  Because  only  ~/.tcshrc
                   is  normally  sourced  before ~/.history, histfile
                   should be set in ~/.tcshrc rather than ~/.login.

                   If histlit is set,  the  first  and  second  forms
                   print  and  save  the literal (unexpanded) form of
                   the history list.

                   The last form clears the history list.

           hup [command] (+)
                   With command, runs command such that it will  exit
                   on  a  hangup signal and arranges for the shell to
                   send it a hangup  signal  when  the  shell  exits.
                   Note  that  commands may set their own response to
                   hangups,  overriding  hup.   Without  an  argument
                   (allowed in only a shell script), causes the shell
                   to exit on a  hangup  for  the  remainder  of  the
                   script.   See  also  Signal handling and the nohup
                   builtin command.

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

           if (expr) then
           ...
           else if (expr2) then
           ...
           else
           ...
           endif   If the specified expr is true then the commands to
                   the first else are executed; otherwise if expr2 is
                   true then the commands to the second else are exe
                   cuted, etc.  Any number of else-if pairs are  pos
                   sible; only one endif is needed.  The else part is
                   likewise optional.  (The words else and endif must
                   appear  at  the  beginning  of input lines; the if
                   must appear alone on its input line  or  after  an
                   else.)
                   signal (or, if none is given, the TERM (terminate)
                   signal) to the specified jobs or  processes.   job
                   may  be a number, a string, `', `%', `+' or `-' as
                   described under Jobs.  Signals are either given by
                   number  or  by name (as given in /usr/include/sig
                   nal.h, stripped of the prefix `SIG').  There is no
                   default  job;  saying  just `kill' does not send a
                   signal to the current job.  If  the  signal  being
                   sent is TERM (terminate) or HUP (hangup), then the
                   job or process is sent a CONT (continue) signal as
                   well.  The third form lists the signal names.

           limit [-h] [resource [maximum-use]]
                   Limits  the consumption by the current process and
                   each process it creates to not individually exceed
                   maximum-use on the specified resource.  If no max
                   imum-use is  given,  then  the  current  limit  is
                   printed; if no resource is given, then all limita
                   tions are given.  If the -h  flag  is  given,  the
                   hard  limits  are used instead of the current lim
                   its.  The hard limits impose a ceiling on the val
                   ues  of  the  current limits.  Only the super-user
                   may raise the hard limits, but a user may lower or
                   raise the current limits within the legal range.

                   Controllable  resources currently include (if sup
                   ported by the OS):

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

                   filesize
                          the  largest  single file which can be cre
                          ated

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

                   stacksize
                          the  maximum  size  of  the  automatically-
                          extended stack region

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

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

                   maxproc
                          the  maximum  number  of  simultaneous pro
                          cesses for this user id

                   sbsize the maximum size of socket buffer usage for
                          this user

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

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

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

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

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

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

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

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

                   listflags  contains  an `x', in which case it acts
                   like `ls -xF'.  ls-F passes its arguments to ls(1)
                   if  it  is  given any switches, so `alias ls ls-F'
                   generally does the right thing.

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

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

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

           nice [+number] [command]
                   Sets the scheduling priority for the shell to num
                   ber, or, without number, to 4.  With command, runs
                   command  at the appropriate priority.  The greater
                   the number, the less cpu the  process  gets.   The
                   super-user  may specify negative priority by using
                   `nice -number ...'.  Command is always executed in
                   a  sub-shell,  and the restrictions placed on com
                   mands in simple if statements apply.

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

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

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

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

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

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

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

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

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

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

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

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

                   or may be relative to the current time:

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

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

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

                   A command in the scheduled-event list is  executed
                   just  before the first prompt is printed after the
                   time when the command is scheduled.  It is  possi
                   ble  to miss the exact time when the command is to
                   be run, but an overdue command will execute at the
                   next  prompt.  A command which comes due while the
                   shell is waiting for user input is executed  imme
                   diately.  However, normal operation of an already-
                   running command will not be interrupted so that  a
                   scheduled-event list element may be run.

                   This mechanism is similar to, but not the same as,
                   the at(1) command on some Unix systems.  Its major
                   disadvantage  is  that it may not run a command at
                   exactly the specified time.  Its  major  advantage
                   is  that  because  sched  runs  directly  from the
                   shell, it has access to shell variables and  other
                   structures.   This provides a mechanism for chang
                   list.  The second  form  sets  name  to  the  null
                   string.   The  third  form sets name to the single
                   word.  The fourth form sets name to  the  list  of
                   words in wordlist.  In all cases the value is com
                   mand and filename expanded.  If -r  is  specified,
                   the value is set read-only.  If -f or -l are spec
                   ified, set only unique words keeping their  order.
                   -f  prefers the first occurrence of a word, and -l
                   the last.  The fifth form sets the index'th compo
                   nent  of name to word; this component must already
                   exist.  The sixth form lists only the names of all
                   shell  variables  that are read-only.  The seventh
                   form makes name read-only, whether or not it has a
                   value.   The  second  form  sets  name to the null
                   string.  The eighth form is the same as the  third
                   form, but make name read-only at the same time.

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

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

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

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

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

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

                   removes it if string is omitted.  (TCF only)

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

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

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

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

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

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

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

           uncomplete pattern (+)
                   Removes all completions whose names match pattern.
                   `uncomplete  *'  thus removes all completions.  It
                   is not an error for nothing to be uncompleted.

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

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

           unlimit [-h] [resource]
                   Removes the  limitation  on  resource  or,  if  no
                   resource  is  specified, all resource limitations.
                   With  -h,  the  corresponding  hard   limits   are
                   removed.  Only the super-user may do this.

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

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

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

                   Reports all known instances of command,  including
                   aliases, builtins and executables in path.

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

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

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

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

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

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

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

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

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

                   Note that putting a cd, pushd or  popd  in  cwdcmd
                   may  cause  an  infinite loop.  It is the author's
                   mand  name  for  which help is sought is passed as
                   sole argument.  For example, if one does

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

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

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

                       > set tperiod = 30
                       > alias periodic checknews

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

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

                       > alias precmd date

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

           postcmd Runs before each command gets executed.

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

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

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

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

           The  shell  sets  addsuffix,  argv,  autologout,  command,
           automatically interconverts the different formats of  path
           and PATH.

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

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

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

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

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

           autoexpand (+)
                   If  set,  the  expand-history  editor  command  is
                   invoked   automatically   before  each  completion
                   attempt.

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

           autologout (+)
                   The  first  word is the number of minutes of inac
                   tivity before automatic logout.  The optional sec
                   ond  word  is  the number of minutes of inactivity
                   before automatic locking.  When the shell automat
                   ically logs out, it prints `auto-logout', sets the
                   variable logout to `automatic'  and  exits.   When
                   the   shell   automatically  locks,  the  user  is
                   required to enter his password to  continue  work
                   ing.   Five incorrect attempts result in automatic
                   logout.  Set to `60' (automatic  logout  after  60
                   minutes,  and  no locking) by default in login and
                   superuser shells, but not if the shell  thinks  it
                   is  running  under a window system (i.e., the DIS
                   PLAY environment variable is set), the  tty  is  a

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

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

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

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

           complete (+)
                   If set to `enhance', completion  1)  ignores  case
                   and  2) considers periods, hyphens and underscores
                   (`.', `-' and  `_')  to  be  word  separators  and
                   hyphens and underscores to be equivalent.

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

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

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

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

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

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

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

           dspmbyte (+)
                   If set to `euc', it enables  display  and  editing
                   EUC-kanji(Japanese)  code.   If  set to `sjis', it
                   enables display  and  editing  Shift-JIS(Japanese)
                   code.   If  set  to `big5', it enables display and
                   editing Big5(Chinese) code.  If set to `utf8',  it
                   enables  display  and  editing Utf8(Unicode) code.
                   If set to the following format, it enables display
                   and editing of original multi-byte code format:

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

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

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

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

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

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

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

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

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

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

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

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

           group (+)
                   The user's group name.

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

           histdup (+)
                   Controls handling of duplicate entries in the his
                   ing the  same  home  directory  between  different
                   machines,  or  when  saving  separate histories on
                   different terminals.  Because  only  ~/.tcshrc  is
                   normally   sourced   before  ~/.history,  histfile
                   should be set in ~/.tcshrc rather than ~/.login.

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

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

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

           ignoreeof
                   If  set  to  the empty string or `0' and the input
                   device is  a  terminal,  the  end-of-file  command
                   (usually  generated  by the user by typing `^D' on
                   an empty line) causes  the  shell  to  print  `Use
                   "exit"  to  leave tcsh.' instead of exiting.  This
                   prevents the shell from accidentally being killed.
                   If set to a number n, the shell ignores n - 1 con
                   secutive end-of-files and exits on the  nth.   (+)
                   If  unset, `1' is used, i.e., the shell exits on a
                   single `^D'.

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

           inputmode (+)
                   If set to `insert' or `overwrite', puts the editor
                   into that input mode  at  the  beginning  of  each
                   line.
                   to  less  than  `2',  the shell will only keep the
                   most recently killed string.

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

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

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

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

           listmaxrows (+)
                   The maximum number of  rows  of  items  which  the
                   list-choices editor command will list without ask
                   ing first.

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

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

           mail    The names of the files or directories to check for
                   incoming   mail,   separated  by  whitespace,  and
                   optionally preceded by  a  numeric  word.   Before
                   each  prompt,  if 10 minutes have passed since the
                   last check, the shell checks each  file  and  says
                   `You  have new mail.' (or, if mail contains multi
                   ple files, `You have new mail in  name.')  if  the
                   filesize  is  greater  than zero in size and has a
                   for those systems which store mail in this manner,
                   such as the Andrew Mail System.

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

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

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

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

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

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

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

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

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

           nostat (+)
                   used  by  cd  and  pushd.   See  also  the cwd and
                   dirstack shell variables.

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

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

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

                   %/  The current working directory.
                   %~  The current working directory, but with  one's
                       home  directory  represented  by `~' and other
                       users' home directories represented by `~user'
                       as per Filename substitution.  `~user' substi
                       tution happens only if the shell  has  already
                       used `~user' in a pathname in the current ses
                       sion.
                   %c[[0]n], %.[[0]n]
                       The trailing component of the current  working
                       directory, or n trailing components if a digit
                       n is given.  If n begins with `0', the  number
                       of  skipped  components  precede  the trailing
                       component(s) in the  format  `/<skipped>trail
                       ing'.   If the ellipsis shell variable is set,
                       skipped  components  are  represented  by   an
                       ellipsis  so  the whole becomes `...trailing'.
                       `~' substitution is done as in `%~' above, but
                       the  `~'  component  is  ignored when counting
                       trailing components.
                   %C  Like %c, but without `~' substitution.
                   %h, %!, !
                       format, with seconds.
                   %P  Like `%p', but in 24-hour format (but see  the
                       ampm shell variable).
                   \c  c is parsed as in bindkey.
                   ^c  c is parsed as in bindkey.
                   %%  A single `%'.
                   %n  The user name.
                   %j  The number of jobs.
                   %d  The weekday in `Day' format.
                   %D  The day in `dd' format.
                   %w  The month in `Mon' format.
                   %W  The month in `mm' format.
                   %y  The year in `yy' format.
                   %Y  The year in `yyyy' format.
                   %l  The shell's tty.
                   %L  Clears  from  the  end of the prompt to end of
                       the display or the end of the line.
                   %$  Expands the shell or environment variable name
                       immediately after the `$'.
                   %#  `>' (or the first character of the promptchars
                       shell variable) for normal users, `#' (or  the
                       second character of promptchars) for the supe
                       ruser.
                   %{string%}
                       Includes string as a literal escape  sequence.
                       It  should  be  used  only  to change terminal
                       attributes and  should  not  move  the  cursor
                       location.  This cannot be the last sequence in
                       prompt.
                   %?  The return code of the command  executed  just
                       before the prompt.
                   %R  In  prompt2,  the  status  of  the parser.  In
                       prompt3, the corrected  string.   In  history,
                       the history string.

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

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

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

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

                   `CORRECT>%R (y|n|e|a)? ' in interactive shells.

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

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

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

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

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

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

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

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

           savehist
                   If  set,  the shell does `history -S' before exit
                   ing.  If the first word is set  to  a  number,  at
                   most  that many lines are saved.  (The number must
                   be less than or equal to history.)  If the  second
                   word is set to `merge', the history list is merged
                   with the existing history file instead of  replac
                   non-builtin command  execution.)   Initialized  to
                   the (system-dependent) home of the shell.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                   %U  The time the process spent in user mode in cpu
                       seconds.
                   %S  The time the process spent in kernel  mode  in
                       cpu seconds.
                   %E  The elapsed (wall clock) time in seconds.
                   %P  The CPU percentage computed as (%U + %S) / %E.
                   %W  Number of times the process was swapped.
                   %X  The average amount in (shared) text space used
                       in Kbytes.
                       (waits).
                   %c  The number of involuntary context switches.

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

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

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

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

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

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

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

           user    The user's login name.

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

           version (+)
                   The  version  ID  stamp.   It contains the shell's
                   version number (see tcsh), origin,  release  date,
                   vendor,  operating system and machine (see VENDOR,
                   OSTYPE and MACHTYPE) and a comma-separated list of
                   options  which  were set at compile time.  Options
                   which are set by default in the  distribution  are
                   dtr Login shells drop DTR when exiting
                   bye bye is a synonym for  logout  and  log  is  an
                       alternate name for watchlog
                   al  autologout is enabled; default
                   kan Kanji  is  used  if  appropriate  according to
                       locale  settings,  unless  the  nokanji  shell
                       variable is set
                   sm  The system's malloc(3) is used
                   hb  The  `#!<program>  <args>'  convention is emu
                       lated when executing shell scripts
                   ng  The newgrp builtin is available
                   rh  The shell attempts to set the REMOTEHOST envi
                       ronment variable
                   afs The shell verifies your password with the ker
                       beros server if  local  authentication  fails.
                       The  afsuser  shell  variable  or  the AFSUSER
                       environment variable override your local user
                       name if set.

                   An  administrator  may enter additional strings to
                   indicate differences in the local version.

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

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

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

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

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

                       set watch = (1 any any)

                   reports  any  login/logout once every minute.  For
                   the impatient, the log builtin command triggers  a
                   watch  report at any time.  All current logins are
                   reported (as with the log builtin) when  watch  is
                   first set.
                       `local' if the login/logout was from the local
                       host.
                   %m  The hostname of the  remote  host  up  to  the
                       first  `.'.  The full name is printed if it is
                       an IP address or an X Window System display.

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

           wordchars (+)
                   A  list  of non-alphanumeric characters to be con
                   sidered part of a word by the forward-word,  back
                   ward-word   etc.,   editor  commands.   If  unset,
                   `*?_-.[]~=' is used.

## ENVIRONMENT

           AFSUSER (+)
                   Equivalent to the afsuser shell variable.

           COLUMNS The number of columns in the terminal.  See Termi
                   nal management.

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

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

           GROUP (+)
                   Equivalent to the group shell variable.

           HOME    Equivalent to the home shell variable.

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

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

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

                   a two-character variable name.  The variables with
                   their associated defaults are:

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

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

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

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

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

                   If  your  terminal  does use ISO 6429 color codes,
                   you can compose the type codes (i.e.,  all  except
                           36  for cyan foreground
                           37  for white (or gray) foreground
                           40  for black background
                           41  for red background
                           42  for green background
                           43  for yellow (or brown) background
                           44  for blue background
                           45  for purple background
                           46  for cyan background
                           47  for white (or gray) background

                   Not  all commands will work on all systems or dis
                   play devices.

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

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

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

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

           PATH    A  colon-separated list of directories in which to
                   look for  executables.   Equivalent  to  the  path
                   shell variable, but in a different format.

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

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

           SHLVL (+)
                   Equivalent to the shlvl shell variable.

           SYSTYPE (+)
                   fg-editor editor command.

## FILES

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

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

## NEW FEATURES (+)

           This manual describes tcsh as a single entity, but experi
           Editor commands (q.v.) which perform  other  useful  func
           tions  in the middle of typed commands, including documen
           tation lookup (run-help), quick editor restarting (run-fg-
           editor) and command resolution (which-command).

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

           Enhanced  directory  parsing and directory stack handling.
           See the cd, pushd, popd and dirs commands and their  asso
           ciated shell variables, the description of Directory stack
           substitution, the dirstack, owd and symlinks  shell  vari
           ables  and the normalize-command and normalize-path editor
           commands.

           Negation in glob-patterns.  See Filename substitution.

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

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

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

           Extensive  terminal-management capabilities.  See Terminal
           management.

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

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

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

           Read-only variables.  See Variable substitution.
           c )'.

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

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

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

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

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

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

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

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

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

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

           Report bugs to tcsh-bugs@mx.gw.com, preferably with fixes.
           If you want to help maintain and test tcsh, send  mail  to
           listserv@mx.gw.com  with  the  text  `subscribe tcsh <your
           name>' on a line by itself in  the  body.   You  can  also
           `subscribe  tcsh-bugs <your name>' to get all bug reports,
           or `subscribe tcsh-diffs <your name>' to get the  develop
           ment list plus diffs for each patchlevel.

## THE T IN TCSH

           In  1964,  DEC produced the PDP-6.  The PDP-10 was a later
           re-implementation.  It was re-christened the  DECsystem-10
           for  PDP-10') objected; thus DEC found themselves support
           ing two incompatible systems  on  the  same  hardware--but
           then there were 6 on the PDP-11!

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

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

## LIMITATIONS

           Words can be no longer than 1024 characters.

           The system limits argument lists to 10240 characters.

           The  number of arguments to a command which involves file
           name expansion is limited to 1/6th the number  of  charac
           ters allowed in an argument list.

           Command  substitutions  may  substitute no more characters
           than are allowed in an argument list.

           To detect looping, the shell restricts the number of alias
           substitutions on a single line to 20.

## SEE ALSO

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

## VERSION

           This manual documents tcsh 6.12.00 (Astron) 2002-07-23.

## AUTHORS

           William Joy
             Original author of csh(1)
           J.E. Kulp, IIASA, Laxenburg, Austria
             Job control and directory stack features
           Ken Greer, HP Labs, 1981
             File name completion
           Mike Ellis, Fairchild, 1983
             Command name recognition/completion
           Paul Placeway, Ohio State CIS Dept., 1983-1993
             Ports to HPUX, SVR2 and SVR3, a SysV version of getwd.c,
             SHORT_STRINGS support and a new version of sh.glob.c
           James J Dempsey, BBN, and Paul Placeway, OSU, 1988
             A/UX port
           Daniel Long, NNSC, 1988
             wordchars
           Patrick Wolfe, Kuck and Associates, Inc., 1988
             vi mode cleanup
           David C Lawrence, Rensselaer Polytechnic Institute, 1989
             autolist and ambiguous completion listing
           Alec Wolman, DEC, 1989
             Newlines in the prompt
           Matt Landau, BBN, 1989
             ~/.tcshrc
           Ray Moody, Purdue Physics, 1989
             Magic space bar history expansion
           Mordechai ????, Intel, 1989
             printprompt() fixes and additions
           Kazuhiro  Honda,  Dept.  of Computer Science, Keio Univer
           sity, 1989
             Automatic spelling correction and prompt3
           Per Hedeland, Ellemtel, Sweden, 1990-
             Various bugfixes, improvements and manual updates
           Hans J. Albertsson (Sun Sweden)
             ampm, settc and telltc
           Michael Bloom
             Interrupt handling fixes
           Michael Fine, Digital Equipment Corp
             Extended key support
           Eric Schnoebelen, Convex, 1990
             Convex  support, lots of csh bug fixes, save and restore
             of directory stack
           Ron Flax, Apple, 1990
             A/UX 2.0 (re)port
           Dan Oscarsson, LTH Sweden, 1990
             NLS support and simulated NLS support for non NLS sites,
             fixes
           Johan Widen, SICS Sweden, 1990
             shlvl, Mach support, correct-line, 8-bit printing
           Matt Day, Sanyo Icon, 1990
             POSIX termio support, SysV limit fixes
           Jaap Vermeulen, Sequent, 1990-91
             Vi  mode fixes, expand-line, window change fixes, Symme
             try port
           Martin Boyer, Institut de recherche d'Hydro-Quebec, 1991
             autolist beeping options, modified the history search to
             search  for  the  whole string from the beginning of the
             line to the cursor.
           Scott Krotz, Motorola, 1991
             Minix port
           David Dawes, Sydney U. Australia, Physics Dept., 1991
             SVR4 job control fixes
             VMS-POSIX port
           Beto Appleton, IBM Corp., 1992
             Walking  process  group fixes, csh bug fixes, POSIX file
             tests, POSIX SIGHUP
           Scott Bolte, Cray Computer Corp., 1992
             CSOS port
           Kaveh R. Ghazi, Rutgers University, 1992
             Tek, m88k, Titan and Masscomp ports  and  fixes.   Added
             autoconf support.
           Mark Linderman, Cornell University, 1992
             OS/2 port
           Mika Liljeberg, liljeber@kruuna.Helsinki.FI, 1992
             Linux port
           Tim  P.  Starrin, NASA Langley Research Center Operations,
           1993
             Read-only variables
           Dave Schweisguth, Yale University, 1993-4
             New man page and tcsh.man2html
           Larry Schwimmer, Stanford University, 1993
             AFS and HESIOD patches
           Luke Mewburn, RMIT University, 1994-6
             Enhanced  directory  printing  in prompt, added ellipsis
             and rprompt.
           Edward Hutchins, Silicon Graphics Inc., 1996
             Added implicit cd.
           Martin Kraemer, 1997
             Ported to Siemens Nixdorf EBCDIC machine
           Amol Deshpande, Microsoft, 1997
             Ported to WIN32 (Windows/95 and Windows/NT);  wrote  all
             the  missing  library and message catalog code to inter
             face to Windows.
           Taga Nayuta, 1998
             Color ls additions.

## THANKS TO

           Bryan Dunlap, Clayton Elwell, Karl Kleinpaste, Bob Manson,
           Steve Romig, Diana Smetters, Bob Sutterfield, Mark Verber,
           Elizabeth Zwicky and all the other people  at  Ohio  State
           for suggestions and encouragement

           All  the people on the net, for putting up with, reporting
           bugs in, and suggesting new additions to  each  and  every
           version

           Richard  M. Alderson III, for writing the `T in tcsh' sec
           tion

    Astron 6.12.00             23 July 2002                   TCSH(1)