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csh(1) [ultrix man page]

csh(1)							      General Commands Manual							    csh(1)

       csh - C shell Command Interpreter

       csh [-cefinstvVxX] [arg...]

       The  command  is  a  command language interpreter that consists of a history mechanism, job control facilities, and a C-like syntax.  While
       this command has a set of built-in functions that it performs directly, the command line interpreter also  reads  and  translates  commands
       that  invokes  other  programs.	Additionally, you can create shell scripts which the command can interpret.  Shell scripts are files which
       contain executable instructions.

       The percent sign (%) represents the system prompt.  It indicates that you can begin entering commands to the  system.   Each  command  line
       that  you type is read and broken into words.  This sequence of words is placed on a command history list and then parsed.  When the entire
       command line has executed, the percent sign reappears and you can enter another command.  See the History Substitution  and  Jobs  sections
       for more information.

       To  use	the  command's full job control facilities, you must invoke the tty driver described in This driver allows generation of interrupt
       characters from the keyboard which stop execution of a job.  For details on setting options in the tty driver, see

       Note that your environment setup is controlled by commands in the home directory of your .cshrc file.  The command executes these  commands
       when  you enter the system.  Additionally, if this is a login shell, the Shell also executes the commands in your .login file.  These files
       usually contain your options for the tty driver and (terminal settings).  When a login shell session ends, commands are executed  from  the
       .logout file in your home directory.

Lexical Structure
       The shell splits input lines into words at blanks and tabs with the following exceptions:

       o    ampersand (&)

       o    bar ( | )

       o    semicolon ( ; )

       o    Left (<) and right (>) angle brackets

       o    Left (() and right ()) parenthesis

       The previous metacharacters form separate words.  If doubled as follows, these metacharacters form single words:

       o    Doubled ampersand (&&)

       o    Double bars (||)

       o    Double left (<<) and right (>>) brackets

       o    Backslash ()

       o    Single (` `) and double (" ") quotation marks.

       Metacharacters can be a part of other words.  Additionally, if you do not want a metacharacter to be interpreted as such by the system, you
       can precede it with a backslash e (e).	A new line that is preceded by a is equivalent to a blank.

       Strings enclosed in single quotes (` `) or strings enclosed in double quotes (" ") form parts of a word.  Metacharacters in these  strings,
       including  blanks  and tabs, do not form separate words.  This is described in more detail later.  Within single quotes or double quotes, a
       new line preceded by a backslash () gives a true new line character.

       When the shell's input is not a terminal, the pound sign (#) introduces a comment which continues to the end of the input line.	It is pre-
       vented this special meaning when preceded by a backslash () and single or double quotation marks.

       A command is a word or sequence of words that directs the system to perform a certain function.	You can separate commands with a bar ( | )
       which forms a pipeline.	The output that results from each command in the pipeline is connected to the input of the next.  For example,	in
       the following pipeline, a file is copied and the output is piped to standard output (the screen):
       % cp /example/dir/test . | more
       You can form and execute several pipelines by separating each pipeline with a semicolon (;).  You can also force a command to complete exe-
       cution in the background by typing an ampersand (&) at the end of the command line.

       You can form a simple command (which may be a component of a pipeline and so on) by placing any of the above in parenthesis  (()).   As	in
       the  C language, you can also separate pipelines with a double bar (||) or double ampersands (&&).  The double bar tells the command inter-
       preter to execute the second command only if the first command fails.  The double ampersands tells the command interpreter to  execute  the
       second command if the first command is successful.

       The  Shell  associates  each  command  or  pipeline  with a job index.  By typing jobs at the system prompt, a table of the current jobs is
       printed on your screen.	Each job listed has a small integer number associated with it.	For example, if you force a  job  into	the  back-
       ground using an ampersand (&), the shell displays the job number and process id of that job as follows:
       [1] 1234

       In the previous example, the job number is 1 indicating that this is a background job and the process id is 1234.

       If  you	are  running a job in the foreground, you can suspend execution of that job by typing a CTRL/Z.  The Shell then indicates that the
       job has been stopped and the system prompt reappears. If you type jobs at the prompt, the display indicates that a job  has  been  stopped.
       You can either enter another command at the prompt or you can manipulate the state of the job you suspended as follows:

       o    Place the job in background by using the bg command.

       o    Continue to execute the job by placing it in the foreground using the fg command.

       A CTRL/Z takes effect immediately and is like an interrupt.  For example, pending output and unread output are discarded when the CTRL/Z is
       issued.	You can also type a CTRL/Y which does not generate a stop signal until a program attempts to perform a operation.

       If a job that is being run in the background attempts to read from the terminal, it will stop.  Background jobs can  produce  output.   You
       can prevent background jobs from producing output by issuing the following command:
       stty tostop

       There  are  several  ways  to refer to jobs in the shell.  For example, to bring job number 1 into the foreground, type %1 or fg %1.  Simi-
       larly, %1 & returns job 1 to the background.  If a job does not have an ambiguous prefix, you can restart a job by it's prefix.	For  exam-
       ple,  %ex  would  restart  a suspended job, if it is the only suspended job.  You use also use %?string which specifies a job whose command
       line contains string.  Again, string cannot be an ambiguous name.

       The Shell tracks the current and previous jobs.	For example, in output displays of jobs, the current job is marked with a  plus  sign  (+)
       and  the  previous  job	is marked with a minus sign (-).  Hence, you can type %+ for the current job and %- for the previous job.  You can
       also specify %% which specifies the current job.

Status Reporting
       The Shell performs status reporting when the process state changes.  For example, if a job becomes blocked and further  processing  is  not
       possible,  the  Shell  informs  you just before it prints a prompt.  If, however, you set the Shell variable notify, the Shell provides you
       with immediate status of background jobs.  As opposed to notifying you of all changes in background jobs, the Shell command notify can mark
       a  single  process  so  that  only  its status change is reported.  To mark a single file, type notify after starting a background job.	By
       default, only the current process is marked.

       If you try to exit from the Shell while jobs are stopped, the following warning appears:
       You have stopped jobs.

       You can use the jobs command to view the stopped jobs. If you immediately try to exit again, the Shell does not provide	a  second  warning
       and suspended jobs are terminated.

       The various transformations the shell performs on the input is now described in the order in which they occur.

History Substitutions
       History	substitutions  allow you to use words from previously typed commands as portions of new commands.  This enables you to repeat com-
       mands, arguments, or fix spelling mistakes from the previous command.

       An exclamation point (!) marks the beginning of a history substitution.	It can appear anywhere in the input stream (including  the  begin-
       ning) as long as it is not nested.  An input line that contains history substitution is echoed to the screen before it is executed.

       The  exclamation  point	(!) may be preceded by a backslash () if you want to escape its special meaning.  If an exclamation point is fol-
       lowed by a blank, tab, new line, equal sign (=), or left parenthesis ((), it is passed unchanged.

       Any command line that is typed at the terminal is saved on the history list.  You can increase or decrease the size of  your  history  list
       using the history variable; the previous command is always retained regardless of its value.  Commands are numbered sequentially from 1. To
       display the history on your terminal, type history at the prompt as follows:
       % history

       This command lists the commands that were previously typed.  For example:
       1  write michael
       2  ex write.c
       3  cat oldwrite.c
       4  diff*write.c

       The commands are shown with their event numbers.  Although it is not usually necessary to use event numbers, you can reinvoke  any  command
       by  combining the exclamation point (!) with any event number.  For example, if you are referencing the previous history list, !4 reinvokes
       the command line diff*write.c.  You can also reinvoke a command without the event number as long as it is not ambiguous.  For  example,	!c
       invokes event 3 or !wri invokes event 1.  The line !?mic? also refers to event 1.  If you type !!, the last command entered in reinvoked.

       To  select  words  from	an  event, follow the event specification with a colon (:) and a designator for the desired words.  The words of a
       input line are numbered from 0, the first (usually command) word being 0, the second word (first argument) being  1,  and  so  forth.   The
       basic word designators are:

	    0	 first (command) word
	    n	 n'th argument
	    !	 first argument,  that is `1'
	    $	 last argument
	    %	 word matched by (immediately preceding) ?s? search
	    x-y  range of words
	    -y	 abbreviates `0-y'
	    *	 abbreviates `!-$', or nothing if only 1 word in event
	    x*	 abbreviates `x-$'
	    x-	 like `x*' but omitting word `$'

       The  colon  (:) separating the event specification from the word designator can be omitted if the argument selector begins with a `!', `$',
       `*' `-' or `%'.	After the optional word designator can be placed a sequence of modifiers, each preceded by a  colon  (:).   The  following
       modifiers are defined:

	    h	   Remove a trailing pathname component, leaving the head.
	    r	   Remove a trailing `.xxx' component, leaving the root name.
	    e	   Remove all but the extension `.xxx' part.
	    s/l/r/ Substitute l for r
	    t	   Remove all leading pathname components, leaving the tail.
	    &	   Repeat the previous substitution.
	    g	   Apply the change globally, prefixing the above, for example, `g&'.
	    p	   Print the new command but do not execute it.
	    q	   Quote the substituted words, preventing further substitutions.
	    x	   Like q, but break into words at blanks, tabs and new lines.

       Unless  preceded by a `g' the modification is applied only to the first modifiable word.  With substitutions, it is an error for no word to
       be applicable.

       The left hand side of substitutions are not regular expressions in the sense of the editors, but rather strings.  Any character may be used
       as  the	delimiter  in  place  of  `/';	a  `' quotes the delimiter into the l and r strings.  The character `&' in the right hand side is
       replaced by the text from the left.  A `' quotes `&' also.  A null l uses the previous string either from a l or from  a  contextual  scan
       string s in `!?s?'.  The trailing delimiter in the substitution may be omitted if a new line follows immediately as may the trailing `?' in
       a contextual scan.

       A special abbreviation of a history reference occurs when the first non-blank character of an input line is  a  circumflex  (^).   This	is
       equivalent  to  `!!:s/'	providing  a  convenient  shorthand for substitutions on the text of the previous line.  Thus `^lb^lib^' fixes the
       spelling of lb in the previous command.	Finally, a history substitution may be surrounded with `{' and `}' if  necessary  to  insulate	it
       from  the characters which follow.  Thus, after `ls -ld ~paul' we might do `!{l}a' to do `ls -ld ~paula', while `!la' would look for a com-
       mand starting `la'.

       Quotations with ' and "

       The quotation of strings by `'' and `"' can be used to prevent all or some of the remaining substitutions.  Strings  enclosed  in  `''  are
       prevented any further interpretation.  Strings enclosed in `"' may be expanded as described below.

       In  both  cases the resulting text becomes (all or part of) a single word; only in one special case (see Command Substitution below) does a
       `"' quoted string yield parts of more than one word; `'' quoted strings never do.

Alias Substitution
       The shell maintains a list of aliases that can be established, displayed, and modified by the alias and unalias commands.

       After the shell scans a command line, it parses the line into distinct commands. Then, the shell checks the first word of each command,	in
       left-to-right  order,  to  determine if the command line contains an alias. When the shell finds an alias, it substitutes the definition of
       the alias for the alias in the command line. The shell reads the definition of the alias using the history mechanism and treats the defini-
       tion  as if it was the previous input line.  If the alias definition makes no reference to the history list, the shell leaves the command's
       argument unchanged.

       For example, the following command creates an alias called ``ls:''
       % alias ls 'ls -l'
       After you issue this alias command, you receive information about files such as their mode, number of links, owner, and so on when you  use
       the ls alias.  For example, the following shows the output from the ls alias created in the preceeding example:
       % ls usrsmithtext_file
       -rw-r--r--  1 smith	    21 Mar 12 11:53 text_file
       You  can  also create aliases that allow you to supply arguments on the command line and arguments in the alias definition, as shown in the
       following example:
       % alias lookup 'grep !^ /etc/passwd'
       You must specify ``'' before the ! to prevent the substitution from occurring in the alias command. The following shows  the  output  from
       the lookup alias:
       % lookup smith
       The lookup alias finds and displays user Smith's entry in the file.

       You  can  specify an alias within an alias definition. After the shell finds an alias and substitutes its definition, it searches again for
       aliases.  The shell flags definitions that begin with the same word as the alias to prevent infinite loops. Other loops	are  detected  and
       cause an error.

       You can use parser metasyntax in an alias command. For example, the following is a valid command that creates the print alias:
       % alias print 'pr !* | lpr'
       The print alias pipes output from the command to the command.

Variable Substitution
       The  shell  maintains  a set of variables, each of which has as value a list of zero or more words.  Some of these 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.

       The values of variables may be displayed and changed by using the set and unset commands.  Of the variables referred to by the shell a num-
       ber 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 setting of this variable results from the -v command line option.

       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 multiword values are ignored.

       After  the  input  line is aliased and parsed, and before each command is executed, variable substitution is performed keyed by `$' charac-
       ters.  This expansion can be prevented by preceding the `$' 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.  Otherwise, the command name  and
       entire argument list are expanded together.  It is thus possible for the first (command) word to this point to generate more than one word,
       the first of which becomes the command name, and the rest of which become arguments.

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

       The  following  metasequences are provided for introducing variable values into the shell input.  Except as noted, it is an error to refer-
       ence a variable which is not set.

	    Are replaced by the words of the value of variable name, each separated by a blank.  Braces insulate name  from  following	characters
	    which  would  otherwise  be  part of it.  Shell variables have names consisting of up to 20 letters and digits starting with a letter.
	    The underscore character is considered a letter.
	    If name is not a shell variable, but is set in the environment, then that value is returned (but : modifiers and the other forms given
	    below are not available in this case).

	    May be used to select only some of the words from the value of name.  The selector is subjected to `$' substitution and may consist of
	    a single number or two numbers separated by a `-'.	The first word of a variables value is numbered `1'.  If the  first  number  of  a
	    range  is omitted it defaults to `1'.  If the last member of a range is omitted it defaults to `$#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.

	    Gives the number of words in the variable.	This is useful for later use in a `[selector]'.

	    Substitutes the name of the file from which command input is being read.  An error occurs if the name is not known.

	    Equivalent to `$argv[number]'.

	    Equivalent to `$argv[*]'.

       The modifiers `:h', `:t', `:r', `:q' and `:x' may be applied to the substitutions above as may `:gh', `:gt' and `:gr'.  If braces  `{'  '}'
       appear in the command form then the modifiers must appear within the braces.  The current implementation allows only one colon (:) modifier
       on each `$' expansion."	The following substitutions may not be modified with colon (:) modifiers.

	    Substitutes the string `1' if name is set, `0' if it is not.

	    Substitutes `1' if the current input file name is known, `0' if it is not.

	    Substitute the (decimal) process number of the (parent) shell.

	    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.

Command And File Name Substitution
       The remaining substitutions, command and file name substitution, are applied selectively to the arguments of built-in 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 per-
       formed, 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 normally broken into separate  words	at
       blanks,	tabs  and  new	lines, with null words being discarded, this text then replacing the original string.  Within `"'s, only new lines
       force new words; blanks and tabs are preserved.

       In any case, the single final new line does not force a new word.  Note that it is thus possible for a command substitution to  yield  only
       part of a word, even if the command outputs a complete line.

File Name Substitution
       If a word contains any of the characters `*', `?', `[' or `{' or begins with the character `~', then that word is a candidate for file name
       substitution, also known as `globbing'.	This word is then regarded as a pattern, and replaced with an alphabetically sorted list  of  file
       names  which  match  the  pattern.  In a list of words specifying file name substitution it is an error for no pattern to match an existing
       file name, but it is not required for each pattern to match.  Only the metacharacters `*', `?' and `[' imply pattern matching, the  charac-
       ters `~' and `{' being more akin to abbreviations.

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

       The character `~' at the beginning of a file name is used to refer to home directories.	Standing alone, that is `~',  it  expands  to  the
       invokers  home  directory  as  reflected  in the value of the variable home.  When followed by a name consisting of letters, digits and `-'
       characters the shell searches for a user with that name and substitutes their home directory;  thus `~ken' might expand to  `/usr/ken'  and
       `~ken/chmach'  to  `/usr/ken/chmach'.   If  the	character  `~' is followed by a character other than a letter or `/' or appears not at the
       beginning of a word, it is left undisturbed.

       The metanotation `a{b,c,d}e' is a shorthand for `abe ace ade'.  Left to right order is preserved, with results of matches being sorted sep-
       arately	 at   a  low  level  to  preserve  this  order.   This	construct  may	be  nested.   Thus  `~source/s1/{oldls,ls}.c'  expands	to
       `/usr/source/s1/oldls.c /usr/source/s1/ls.c' whether or not these files exist without any  chance  of  error  if  the  home  directory  for
       `source' is `/usr/source'.  Similarly `../{memo,*box}' might expand to `../memo ../box ../mbox'.  (Note that `memo' was not sorted with the
       results of matching `*box'.)  As a special case `{', `}' and `{}' are passed undisturbed.

       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 file name expanded) as the standard input.

       << word
	    Read the shell input up to a line which is identical to word.  Word is not subjected to variable, file name 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 intervening lines, allowing `' to quote `$', `' and ``'.  Com-
	    mands  which  are  substituted  have  all  blanks, tabs, and new lines preserved, except for the final new line which is dropped.  The
	    resultant text is placed in an anonymous temporary file which is given to the command as standard input.

       > name
       >! name
       >& name
       >&! name
	    The file name is used as standard output.  If the file does not exist then it is created; if the file exists,  it  is  truncated,  its
	    previous contents being lost.

	    If the variable noclobber is set, then the file must not exist or be a character special file (for example, a terminal or `/dev/null')
	    or an error results.  This helps prevent accidental destruction of files.  In this case the `!' forms can be used  and  suppress  this

	    The  forms	involving `&' route the diagnostic output into the specified file as well as the standard output.  Name is expanded in the
	    same way as `<' input file names are.

       >> name
       >>& name
       >>! name
       >>&! name
	    Uses file name as standard output like `>' but places output at the end of the file.  If the variable noclobber is set, then it is	an
	    error for the file not to exist unless one of the `!' forms is given.  Otherwise similar to `>'.

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

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

       A  number  of the built-in commands (to be described subsequently) take expressions, in which the operators are similar to those of C, with
       the same precedence.  These expressions appear in the @, exit, if, and while commands.  The following operators are available:

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

       Here the precedence increases to the right, `==' `!=' `=~' and `!~', `<=' `>=' `<' and `>', `<<' and `>>', `+' and `-',	`*'  `/'  and  `%'
       being,  in groups, at the same level.  The `==' `!=' `=~' and `!~' operators compare their arguments as strings; all others operate on num-
       bers.  The operators `=~' and `!~' are like `!=' and `==' except that the right hand side is a pattern (containing, for example, `*'s, `?'s
       and  instances of `[...]')  against which the left hand operand is matched.  This reduces the need for use of the switch statement 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 result  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 syntactically significant to the parser (`&' `|' `<' `>' `(' `)')  they  should
       be surrounded by spaces.

       Also  available	in  expressions  as  primitive	operands are command executions enclosed in `{' and `}' and file enquiries of the form `-l
       name' where l is one of:

	    r	 read access
	    w	 write access
	    x	 execute access
	    e	 existence
	    o	 ownership
	    z	 zero size
	    f	 plain file
	    d	 directory

       The specified name is command and file name expanded and then tested to see if it has the specified relationship to the real user.  If  the
       file  does  not exist or is inaccessible then all enquiries return false, that is `0'.  Command executions succeed, returning true, that is
       `1', if the command exits with status 0, otherwise they fail, returning false, that  is	`0'.   If  more  detailed  status  information	is
       required then the command should be executed outside of an expression and the variable status examined.

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

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

       If the shell's input is not seekable, the shell buffers up input 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 goto's will succeed on non-seekable inputs.)

Built-in Commands
       Built-in  commands  are	executed within the shell.  If a built-in command occurs as any component of a pipeline except the last then it is
       executed in a subshell.

       alias name
       alias name wordlist
	    The first form prints all aliases.	The second form prints the alias for name.  The final form assigns the specified wordlist  as  the
	    alias of name; wordlist is command and file name substituted.  Name is not allowed to be alias or unalias.

	    Shows  the	amount of dynamic core in use, broken down into used and free core, and address of the last location in the heap.  With an
	    argument shows each used and free block on the internal dynamic memory chain indicating its address, size, and whether it is  used	or
	    free.   This is a debugging command and may not work in production versions of the shell; it requires a modified version of the system
	    memory allocator.

       bg %job ...
	    Puts the current or specified jobs into the background, continuing them if they were stopped.

	    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.

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

       case label:
	    A label in a switch statement as discussed below.

       cd name
       chdir name
	    Change the shell's working directory to directory name.  If no argument is given then change to the home directory of the user.
	    If	name  is not found as a subdirectory of the current directory (and does not begin with `/', `./' or `../'), then each component of
	    the variable cdpath is checked to see if it has a subdirectory name.  Finally, if all else fails but name is a  shell  variable  whose
	    value begins with `/', then this is tried to see if it is a directory.

	    Continue execution of the nearest enclosing while or foreach.  The rest of the commands on the current line are executed.

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

	    Prints the directory stack; the top of the stack is at the left, the first directory in the stack being the current directory.

       echo wordlist
       echo -n wordlist
	    The  specified  words  are	written  to the shell's standard output, separated by spaces, and terminated with a new line unless the -n
	    option is specified.

	    See the description of the foreach, if, switch, and while statements below.

       eval arg ...
	    As in sh(1).  The arguments are read as input to the shell and the resulting command(s) executed in the context of the current  shell.
	    This  is  usually  used  to  execute commands generated as the result of command or variable substitution, since parsing occurs before
	    these substitutions.  See for an example of using eval.

       exec command
	    The specified command is executed in place of the current shell.

	    The shell exits either with the value of the status variable (first form) or with the value of the specified expr (second form).

       fg %job ...
	    Brings the current or specified jobs into the foreground, continuing them if they were stopped.

       foreach name (wordlist)
	    The variable name is successively set to each member of wordlist and the sequence of commands between this command	and  the  matching
	    end are executed.  (Both foreach and end must appear alone on separate lines.)

	    The built-in command continue may be used to continue the loop prematurely and the built-in command break to terminate it prematurely.
	    When this command is read from the terminal, the loop is read up once prompting with `?' before any statements in the  loop  are  exe-
	    cuted.  If you make a mistake typing in a loop at the terminal you can rub it out.

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

       goto word
	    The specified word is file name and command expanded to yield a string of the form `label'.  The shell rewinds its input  as  much	as
	    possible  and  searches  for a line of the form `label:' possibly preceded by blanks or tabs.  Execution continues after the specified

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

       history n
       history -r n
       history -h n
	    Displays the history event list; if n is given only the n most recent events are printed.  The -r option reverses the order of  print-
	    out  to  be  most recent first rather than oldest first.  The -h option causes the history list to be printed without leading numbers.
	    This is used to produce files suitable for sourcing using the -h option to source.

       if (expr) command
	    If the specified expression evaluates true, then the single command with arguments is executed.  Variable substitution on command hap-
	    pens  early,  at  the  same  time it does for the rest of the if command.  Command must be a simple command, not a pipeline, a command
	    list, or a parenthesized command list.  Input/output redirection occurs even if expr is false, when command is not executed (this is a

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

       jobs -l
	    Lists the active jobs; given the -l options lists process id's in addition to the normal information.

       kill %job
       kill -sig %job ...
       kill pid
       kill -sig pid ...
       kill -l
	    Sends either the TERM (terminate) signal or the specified signal to the specified jobs or processes.  Signals are either given by num-
	    ber or by names (as given in /usr/include/signal.h, stripped of the prefix ``SIG'').  The signal names  are  listed  by  ``kill  -l''.
	    There  is  no  default, 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 will be sent a CONT (continue) signal as well.

       limit resource
       limit 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 maximum-use is given, then the current limit is printed; if no resource is given, then all limitations are given.

	    The following resources can be controlled:

       o    cputime (maximum number of cpu-seconds to be used by each process)

       o    filesize (largest single file which can be created)

       o    datasize (the maximum growth of the data+stack region by beyond the end of the program text)

       o    stacksize (the maximum size of the automatically-extended stack region)

       o    coredumpsize (the size of the largest core dump that can be created).

       o    memoryuse (the maximum amount of main memory a process is allowed to occupy)

	    The  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, unambiguous prefixes of the names suffice.

	    Terminate a login shell, replacing it with an instance of /bin/login.  This is one way to log off, included for compatibility with

	    Terminate a login shell.  Especially useful if ignoreeof is set.

       nice +number
       nice command
       nice +number command
	    The first form sets the nice for this shell to 4.  The second form sets the nice to the given number.  The final two forms run command
	    at priority 4 and number respectively.  The super-user may specify negative niceness by using `nice -number ...'.  Command	is  always
	    executed in a sub-shell, and the restrictions place on commands in simple if statements apply.

       nohup command
	    The  first	form  can be used in shell scripts to cause hangups to be ignored for the remainder of the script.  The second form causes
	    the specified command to be run with hangups ignored.  All processes detached with `&' are effectively nohup'ed.

       notify %job ...
	    Causes the shell to notify the user asynchronously when the status of the current or specified jobs changes; normally notification	is
	    presented before a prompt.	This is automatic if the shell variable notify is set.

       onintr  -
       onintr  label
	    Control the action of the shell on interrupts.  The first form restores the default action of the shell on interrupts which is to ter-
	    minate shell scripts or to return to the terminal command input level.  The second	form  `onintr  -'  causes  all	interrupts  to	be
	    ignored.   The  final  form  causes  the  shell  to execute a `goto label' when an interrupt is received or a child process terminates
	    because it was interrupted.

	    In any case, if the shell is running detached and interrupts are being ignored, all forms of onintr have  no  meaning  and	interrupts
	    continue to be ignored by the shell and all invoked commands.

       popd +n
	    Pops the directory stack, returning to the new top directory.  With a argument `+n' discards the nth entry in the stack.  The elements
	    of the directory stack are numbered from 0 starting at the top.

       pushd name
       pushd +n
	    With no arguments, pushd exchanges the top two elements of the directory stack.  Given a name  argument,  pushd  changes  to  the  new
	    directory  (using and pushes the old current working directory (as in csw) onto the directory stack.  With a numeric argument, rotates
	    the nth argument of the directory stack around to be the top element and changes to it.  The members of the directory stack  are  num-
	    bered from the top starting at 0.

	    Causes  the  internal hash table of the contents of the directories in the path variable to be recomputed.	This is needed if new com-
	    mands are added to directories in the path while you are logged in.  This should only be necessary if you add commands to one of  your
	    own directories, or if a systems programmer changes the contents of one of the system directories.

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

       set name
       set name=word
       set name[index]=word
       set name=(wordlist)
	    The first form of the command shows the value of all shell variables.  Variables which have other than a single word as value print as
	    a  parenthesized  word  list.  The second form sets name to the null string.  The third form sets name to the single word.	The fourth
	    form sets the index'th component of name to word; this component must already exist.  The final form sets name to the list of words in
	    wordlist.  In all cases the value is command and file name expanded.

	    These arguments may be repeated to set multiple values in a single set command.  Note however, that variable expansion happens for all
	    arguments before any setting occurs.

       setenv name value
	    Sets the value of environment variable name to be value, a single string.  The most commonly used environment variable USER, TERM, and
	    PATH are automatically imported to and exported from the variables user, term, and path; there is no need to use setenv for these.

       shift variable
	    The  members of argv are shifted to the left, discarding argv[1].  It is an error for argv not to be set or to have less than one word
	    as value.  The second form performs the same function on the specified variable.

       source name
       source -h name
	    The shell reads commands from name.  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.  Normally input during source commands is not
	    placed on the history list; the -h option causes the commands to be placed in the history list without being executed.

       stop %job ...
	    Stops the current or specified job which is executing in the background.

	    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

       switch (string)
       case str1:
	    Each  case	label  is  successively  matched,  against  the  specified string which is first command and file name 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 endsw.

       time command
	    With  no argument, a summary of time used by this shell and its children is printed.  If arguments are given the specified simple com-
	    mand is timed and a time summary as described under the time variable is printed.  If necessary, an extra shell is	created  to  print
	    the time statistic when the command completes.

       umask value
	    The  file  creation  mask  is displayed (first form) or set to the specified value (second form).  The mask is given in octal.  Common
	    values for the mask are 002 giving all access to the group and read and execute access to others or 022 giving all	access	except	no
	    write access for users in the group or others.

       unalias pattern
	    All  aliases  whose names match the specified pattern are discarded.  Thus all aliases are removed by `unalias *'.	It is not an error
	    for nothing to be unaliased.

	    Use of the internal hash table to speed location of executed programs is disabled.

       unlimit resource
	    Removes the limitation on resource.  If no resource is specified, then all resource limitations are removed.

       unset pattern
	    All variables whose names match the specified pattern are removed.	Thus all variables are removed by `unset *'; this  has	noticeably
	    distasteful side-effects.  It is not an error for nothing to be unset.

       unsetenv pattern
	    Removes all variables whose name match the specified pattern from the environment.	See also the setenv command above and

	    All  background  jobs  are	waited	for.  It the shell is interactive, then an interrupt can disrupt the wait, at which time the shell
	    prints names and job numbers of all jobs known to be outstanding.

       while (expr)
	    While the specified expression evaluates non-zero, the commands between the while and the matching end are evaluated.  Break and  con-
	    tinue may be used to terminate or continue the loop prematurely.  (The while and end must appear alone on their input lines.)  Prompt-
	    ing occurs here the first time through the loop as for the foreach statement if the input is a terminal.

	    Brings the specified job into the foreground.

       %job &
	    Continues the specified job in the background.

       @ name = expr
       @ name[index] = expr
	    The first form prints the values of all the shell variables.  The second form sets the specified name to the value of  expr.   If  the
	    expression	contains  `<',	`>',  `&'  or `|' then at least this part of the expression must be placed within `(' `)'.  The third form
	    assigns the value of expr to the index'th argument of name.  Both name and its index'th component must already exist.

	    The operators `*=', `+=', etc are available as in C.  The space separating the name from the assignment operator is optional.   Spaces
	    are, however, mandatory in separating components of expr which would otherwise be single words.

	    Special postfix `++' and `--' operators increment and decrement name respectively, that is `@  i++'.

Pre-defined And Environment Variables
       The following variables have special meaning to the shell.  Of these, argv, cwd, home, path, prompt, shell and status are always set by the
       shell.  Except for cwd and status this setting occurs only at initialization; these variables will not then be modified unless this is done
       explicitly by the user.

       This  shell copies the environment variable USER into the variable user, TERM into term, and HOME into home, and copies these back into the
       environment whenever the normal shell variables are reset.  The environment variable PATH is likewise handled.	It  is	not  necessary	to
       worry about its setting other than in the file as inferior processes will import the definition of path from the environment, and re-export
       it if you then change it.

       argv	      Set to the arguments to the shell, it is from this variable that positional parameters are  substituted,	that  is  `$1'	is
		      replaced by `$argv[1]', and so forth.

       cdpath	      Gives a list of alternate directories searched to find subdirectories in chdir commands.

       cwd	      The full pathname of the current directory.

       echo	      Set  when  the  -x  command line option is given.  Causes each command and its arguments to be echoed just before it is exe-
		      cuted.  For non-built-in commands all expansions occur before echoing.  Built-in commands are echoed before command and file
		      name substitution, since these substitutions are then done selectively.

       histchars      Can be given a string value to change the characters used in history substitution.  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.

       history	      Can  be  given  a numeric value to control the size of the history list.	Any command which has been referenced in this many
		      events will not be discarded.  Too large values of history may run the shell out of memory.  The last  executed  command	is
		      always saved on the history list.

       home	      The  home  directory  of the invoker, initialized from the environment.  The file name expansion of `~' refers to this vari-

       ignoreeof      If set the shell ignores end-of-file from input devices which are terminals.  This prevents shells from  accidentally  being
		      killed by control-D's.

       mail	      The  files  where the shell checks for mail.  This is done after each command completion which will result in a prompt, if a
		      specified interval has elapsed.  The shell says `You have new mail.'  if the file exists with an	access	time  not  greater
		      than its modify time.

		      If  the  first  word  of	the value of mail is numeric it specifies a different mail checking interval, in seconds, than the
		      default, which is 10 minutes.

		      If multiple mail files are specified, then the shell says `New mail in name' when there is mail in the file name.

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

       noglob	      If  set,	file  name expansion is inhibited.  This is most useful in shell scripts which are not dealing with file names, or
		      after a list of file names has been obtained and further expansions are not desirable.

       nonomatch      If set, it is not an error for a file name expansion to not match any  existing  files;  rather  the  primitive  pattern	is
		      returned.  It is still an error for the primitive pattern to be malformed, that is `echo [' still gives an error.

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

       path	      Each word of the path variable specifies a directory in which commands are to be sought for execution.  A null  word  speci-
		      fies  the current directory.  If there is no path variable then only full path names will execute.  The usual search path is
		      `.', `/bin' and `/usr/bin', but this may vary from system to system.  For the super-user the default search path is  `/etc',
		      `/bin'  and  `/usr/bin'.	 A  shell  which  is given neither the -c nor the -t option will normally hash the contents of the
		      directories in the path variable after reading and each time the path variable is reset.	If new commands are added to these
		      directories while the shell is active, it may be necessary to give the rehash or the commands may not be found.

       prompt	      The  string which is printed before each command is read from an interactive terminal input.  If a `!' appears in the string
		      it will be replaced by the current event number unless a preceding `' is given.	Default is `% ', or `# '  for  the  super-

       savehist       is  given  a  numeric  value to control the number of entries of the history list that are saved in ~/.history when the user
		      logs out.  Any command which has been referenced in this many events will be saved.   During  start  up  the  shell  sources
		      ~/.history  into	the  history list enabling history to be saved across logins.  Too large values of savehist will slow down
		      the shell during start up.

       shell	      The file in which the shell resides.  This is used in forking shells to interpret files which have  execute  bits  set,  but
		      which  are not executable by the system.	(See the description of Non-built-in Command Execution below.)	Initialized to the
		      (system-dependent) home of the shell.

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

       time	      Controls	automatic  timing  of commands.  If set, then any command which takes more than this many cpu seconds will cause a
		      line giving user, system, and real times and a utilization percentage which is the ratio of user plus system times  to  real
		      time  to	be printed when it terminates.	The time command can be used to cause a command to be timed no matter how much CPU
		      time it takes.  Thus
		      % time cp /etc/rc /usr/bill/rc
		      0.0u 0.1s 0:01 8% 2+1k 3+2io 1pf+0w
		      % time wc /etc/rc /usr/bill/rc
			52   178  1347 /etc/rc
			52   178  1347 /usr/bill/rc
			104  356  2694 total
		      0.1u 0.1s 0:00 13% 3+3k 5+3io 7pf+0w
		      The preceding example indicates that the cp command used a negligible amount of user time (u) and about 1/10th of  a  second
		      system time (s); the elapsed time was 1 second (0:01), there was an average memory usage of 2k bytes of program space and 1k
		      bytes of data space over the cpu time involved (2+1k); the program did three disk reads and two  disk  writes  (3+2io),  and
		      took  one  page  fault and was not swapped (1pf+0w).  The word count command on the other hand used 0.1 seconds of user time
		      and 0.1 seconds of system time in less than a second of elapsed time.  The percentage `13%' indicates that over  the  period
		      when it was active the command `wc' used an average of 13 percent of the available CPU cycles of the machine.

       verbose	      Set by the -v command line option, causes the words of each command to be printed after history substitution.

Non-built-in Command Execution
       When a command to be executed is found to not be a built-in command the shell attempts to execute the command via Each word in the variable
       path names a directory from which the shell will attempt to execute the command.  If it is given neither a -c nor a -t  option,	the  shell
       will  hash  the names in these directories into an internal table so that it will only try an exec in a directory if 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), or if the shell was given a -c or -t argument, and in any case for each directory com-
       ponent of path which does not begin with a `/', the shell concatenates with the given command name to form a path name of a file  which	it
       then attempts to execute.

       Parenthesized  commands	are  always executed in a subshell.  Thus `(cd ; pwd) ; pwd' prints the home directory; leaving you where you were
       (printing this after the home directory), while `cd ; pwd' leaves you in the home directory.  Parenthesized commands are most often used to
       prevent chdir from affecting the current shell.

       If  the	file  has execute permissions but is not an executable binary to the system, then it is assumed to be a file containing shell com-
       mands and a new shell is spawned to read it.

       If there is an alias for shell then the words of the alias will be prepended to the argument list to form the  shell  command.	The  first
       word  of the alias should be the full path name of the shell (for example, `$shell').  Note that this is a special, late occurring, case of
       alias substitution, and only allows words to be prepended to the argument list without modification.

Argument List Processing
       If argument 0 to the shell is `-' then this is a login shell.  The flag arguments are interpreted as follows:

       -c   The first argument word is taken to be a command string.  All remaining argument words are placed in argv.

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

       -f   The shell will start faster, because it will neither search for nor execute commands from the  file  `.cshrc'  in  the  invokers  home

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

       -n   Commands are parsed, but not executed.  This aids in syntactic checking of shell scripts.

       -s   Command input is taken from the standard input.

       -t   A single line of input is read and executed.  A `' may be used to escape the new line at the end  of  this  line  and  continue  onto
	    another line.

       -v   Causes the verbose variable to be set, with the effect that command input is echoed after history substitution.

       -x   Causes the echo variable to be set, so that commands are echoed immediately before execution.

       -V   Causes the verbose variable to be set even before `.cshrc' is executed.

       -X   Causes the echo variable to be set before `.cshrc' is executed.

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

Signal Handling
       The  shell  normally ignores quit signals.  Jobs running detached (either by `&' or the bg or %... & commands) are immune to signals gener-
       ated from the keyboard, including hangups.  Other signals have the values which the shell inherited from its parent.  The  shells  handling
       of  interrupts and terminate signals in shell scripts can be controlled by onintr.  Login shells catch the terminate signal; otherwise this
       signal is passed on to children from the state in the shell's parent.  In no case are interrupts allowed when a login shell is reading  the
       file `.logout'.

Command And Filename Recognition
       The command recognizes and completes user name aliases, commands (including built-in commands), and filenames.  To use this feature, do the

       1. Type enough characters at the prompt to make your input to the system unique.

       2. Press the ESC key.

       If your input is unique, the Shell completes the input line.  If the input is not unique, the terminal signals you with	a  beep.   If  you
       receive a beep, type CTRL/D for a list of options.  You can then type the additional characters that will make your text unique.  After you
       have provided more input, press the ESC key again.

Command Line Editing
       The command allows you to visually edit command lines using either a or environment.  The interface is modal and supports a subset of  com-
       mands.	The  interface	is  modeless and supports a subset of commands.  See the Editing Interface section for a list of the available and

       To set the editing environment, define the Shell environment variable CSHEDIT as or If the environment variable CSHEDIT is not defined, the
       command searches for your EDITOR environment variable.  When your EDITOR environment variable is set to or the command defaults to the com-
       mand interface.	If your EDITOR environment is not set to any of the previously mentioned editors, the default is  the  command	interface.
       Note that if neither the CSHEDIT or EDITOR environment variables are defined, the command defaults to the command interface.

       The  new  history  modifier  (:v) allows you to pull commands from the history list to make them available for editing in visual edit mode.
       The symbol :v tells the Shell that you want to enter visual edit mode.  For example, the following command line invokes edit mode  for  the
       previously typed command line:
       When you press the ESC key as the first character on a command line, it is equivalent to typing the following:
       Thus, the previous example invokes edit mode for the last command you entered.

       Another	useful editing feature is scrolling through the history list.  After you have entered edit mode by typing either !command:v or the
       ESC key, you can use the up-arrow and down-arrow keys to scroll through the history list and you may edit any command line in that  history

       When  you  are  in edit mode, all control characters are displayed as a space character.  Additional control characters cannot be inserted.
       Existing control characters are preserved.

Editing Interface
       The available commands follow:

       h	      Move left one character (r).

       l	      Move right one character (r).

       0	      Move to the start of the line.

       $	      Move to the end of the line.

       w	      move forward one word (r).

       b	      Move back one word (r).

       e	      Move to end of word (r).

       fx	      Move forward onto character (r).

       Fx	      Move back onto character (r).

       tx	      Move forward up to character (r).

       Tx	      Move back up to character (r).

       %	      Move to matching bracket ({[]}).

       i	      Insert text before cursor.

       I	      Insert text at beginning of line.

       a	      Append text after cursor.

       A	      Append text at end of line.

       c	      Change text (o).

       C	      Change to end of line (eol) (c$).

       <esc>	      End insertion.

       x	      Delete char under cursor (r).

       X	      Delete character before cursor (r).

       r	      Replace a character (r).

       ~	      Change case of current character (r).

       d	      Delete text (o).

       D	      Delete to eol (d$).

       u	      Undo last change.

       U	      Undo all changes.

       .	      Repeat last text change command (r).

       p	      Put text from previous delete after cursor (r).

       P	      Put text from previous delete before cursor (r).

       ^L,^R	      Redraw command line.

       /word	      Search back through the history list for a command containing the specified word.  If the specified word is  not	delineated
		      by white space in the history list, the search fails.  Typing ESCAPE or CTRL/C aborts this command.

       n	      Repeat last history search.

       <RETURN>       End edit and execute command.

       ^C	      Quit; no command executed.

       (r)	      A repeat count is accepted.

       (o)	      Works within a cursor motion object.

       The available commands follow:

       ^@	      Set mark (keyword null).

       ^A	      Move to beginning of line.

       ^B,	      Move backward a character.

       ^C	      Exit command line edit; do not execute a command.

       ^D	      Delete next character (to kill buffer).

       ^E	      Move to end of line.

       ^F,	      Move forward a character.

       ^G	      Cancel partial command.

       ^H,DEL	      Delete previous character (to kill buffer).

       ^K	      Kill (delete) to end of line (to kill buffer).

       ^L	      Redraw line display.

       ^R	      Search reverse for a single character.

       ^S	      Search forward for a single character.

       ^T	      Transpose two characters before cursor.

       ^Un	      Specify a repeat count before command (default of n is 4).

       ^W	      Delete between cursor and mark (to kill buffer).

       ^Y	      Yank from kill buffer.

       CR,NL	      End edit and execute command.

       ESC-^C	      End edit and execute command.

       ESC-B	      Move backward a word.

       ESC-D	      Delete next word.

       ESC-F	      Move forward a word.

       ESC-H	      Delete previous word.

       ESC-DEL	      Delete previous word.

       ESC-n	      Repeat count before command.

       ^X^C	      End edit and execute command.

       ^Xu	      Undo last change.

       ^XU	      Undo all changes.

       ^X~	      Change case of next character.

       ^X^Sword       Search  back through the history list for a command containing a specified word.	If the specified word is not delineated by
		      white space in the history list, the search fails.  Typing  ESCAPE or CTRL/C aborts this command.

       ^X^S	      Repeat last history search command.  You must be in search mode to issue this command.  Note that ^G  cancels  the  previous
		      search word so that you can enter a new word.

       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 1/6'th the number of characters allowed in an argu-
       ment 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.

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

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

       Commands  within loops, prompted for by `?', are not placed in the history list.  Control structure 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.

       It  should  be  possible  to  use the colon (:) modifiers on the output of command substitutions.  All and more than one colon (:) modifier
       should be allowed on `$' substitutions.

       Symbolic links fool the shell.  In particular, dirs and `cd ..' don't work properly once you've crossed through a symbolic link.

       ~/.cshrc 	Read at beginning of execution by each shell.
       ~/.login 	Read by login shell, after `.cshrc' at login.
       ~/.logout	Read by login shell, at logout.
       /bin/sh		Standard shell, for shell scripts not starting with a `#'.
       /tmp/sh* 	Temporary file for `<<'.
       /etc/passwd	Source of home directories for `~name'.

See Also
       sh(1), time(1), access(2), execve(2), fork(2), killpg(2), pipe(2), sigvec(2), setrlimit(2),  umask(2),  wait(2),  tty(4),  a.out(5),  envi-
       ron(7), time(7)
       "An Introduction to the C shell", Supplementary Documents, Volume 1: General User

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