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csh(1)			    General Commands Manual			csh(1)

       csh - a shell (command interpreter) with	C-like syntax

       [command_file] [argument_list ...]

       is  a  command language interpreter that	incorporates a command history
       buffer, C-like syntax, and job control facilities.

   Command Options
       Command options are interpreted as follows:

	      Read commands from the (single) following	argument which must be
			Any remaining arguments	are placed in

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

	      Suppress execution of the
			file  in  your	home directory,	thus speeding up shell
			start-up time.

	      Force	to respond interactively when  called  from  a	device
			other  than  a computer	terminal (such as another com-
			puter).	 normally responds non-interactively.	If  is
			called	from  a	 computer terminal, it always responds
			interactively, regardless of  which  options  are  se-

	      Parse but	do
			execute	 commands.  This is useful for checking	syntax
			in shell scripts.   All	 substitutions	are  performed
			(history, command, alias, etc.).

	      Take command input from the standard input.

	      Read and execute a single	line of	input.

	      Set the	shell  variable, causing command input to be echoed to
			the standard output device after history substitutions
			are made.

	      Set the	shell  variable,  causing all commands to be echoed to
			the standard error immediately before execution.

	      Disable the tenex	features which use the
			ESC key	for command/file name completion and for list-
			ing available files (see the section below)

	      Set the	variable  before  is executed so that all commands are
			also echoed to the standard output.

	      Set the	variable before	is executed so that all	 commands  are
			also echoed to the standard output.

       After  processing the command options, if arguments remain in the argu-
       ment list, and the or options were not specified, the  first  remaining
       argument	is taken as the	name of	a file of commands to be executed.

       A  simple  command is a sequence	of words, the first of which specifies
       the command to be executed.  A sequence of simple commands separated by
       vertical	 bar  characters forms a pipeline.  The	output of each command
       in a pipeline becomes the input for the next command in	the  pipeline.
       Sequences of pipelines can be separated by semicolons which causes them
       to be executed sequentially.  A sequence	of pipelines can  be  executed
       in  background mode by adding an	ampersand character after the last en-

       Any pipeline can	be placed in parentheses  to  form  a  simple  command
       which,  in turn,	can be a component of another pipeline.	 Pipelines can
       also be separated by or indicating, as in the C language, that the sec-
       ond pipeline is to be executed only if the first	fails or succeeds, re-

       associates a with each pipeline and  keeps  a  table  of	 current  jobs
       (printed	 by the	command) and assigns them small	integer	numbers.  When
       a job is	started	asynchronously using the shell prints  a  line	resem-

	      [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 want to do something else,	you  can  type
       the  currently  defined suspend character (see termio(7)) which sends a
       stop signal to the current job.	then normally indicates	that  the  job
       has been	`Stopped', and prints another prompt.  You can then manipulate
       the state of this job, putting it in the	background with	 the  command,
       run  some  other	 commands, and then eventually bring the job back into
       the foreground with the foreground command A suspend takes effect imme-
       diately	and is like an interrupt in that pending output	and unread in-
       put are discarded when it is typed.  There is a delayed suspend charac-
       ter  which  does	not generate a stop signal until a program attempts to
       read(2) it.  This can usefully be typed ahead when  you	have  prepared
       some commands for a job which you want to stop after it has read	them.

       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 (see stty(1)).  If you set
       this tty	option,	background jobs	stop when they try to produce  output,
       just  as	 they  do  when	 they try to read input.  Keyboard signals and
       line-hangup signals from	the terminal interface are not sent  to	 back-
       ground  jobs  on	such systems.  This means that background jobs are im-
       mune to the effects of logging out or typing the	interrupt, quit,  sus-
       pend, and delayed suspend characters (see termio(7)).

       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  Just  naming a job	brings it to the foreground; thus is a
       synonym for bringing job	1 back into the	foreground.  Similarly,	typing
       resumes job 1 in	the background.	 Jobs can also be named	by prefixes of
       the string typed	in to start them if these  prefixes  are  unambiguous;
       thus normally restarts a	suspended ex(1)	job, if	there is only one sus-
       pended job whose	name begins with the string It is also possible	to say
       which  specifies	a job whose text contains string, if there is only one
       such job.

       maintains a notion of the current and previous jobs.   In  output  per-
       taining	to jobs, the current job is marked with	a and the previous job
       with a The abbreviation refers to the current job  and  refers  to  the
       previous	 job.  For close analogy with the syntax of the	mechanism (de-
       scribed below), is also a synonym for the current job.

       learns immediately whenever a process changes state.  It	 normally  in-
       forms you whenever a job	becomes	blocked	so that	no further progress is
       possible, but only just before printing a prompt.  This is done so that
       it  does	 not  otherwise	 disturb  your work.  If, however, you set the
       shell variable notifies you immediately of changes in status  of	 back-
       ground  jobs.   There  is  also a built-in command called which marks a
       single process so that any status change	is immediately	reported.   By
       default,	marks the current process.  Simply type	after starting a back-
       ground job to mark it.

       If you try to leave the shell while jobs	are stopped, sends the warning
       message:	Use the	command	to see what they are.  If you do this or imme-
       diately try to exit again, does not warn	you a  second  time,  and  the
       suspended jobs are terminated (see exit(2)).

   Built-In Commands
       Built-in	 commands are executed within the shell	without	spawning a new
       process.	 If a built-in command occurs as any component of  a  pipeline
       except  the  last, it is	executed in a subshell.	 The built-in commands

	      The first	form prints all	aliases.
		      The second form prints the alias for  name.   The	 third
		      form  assigns  the  specified  wordlist  as the alias of
		      name.  Command and file name substitution	are  performed
		      on wordlist.  name cannot	be or

	      Put the current
		      (job  not	 specified)  or	 specified jobs	into the back-
		      ground, continuing them if they were stopped.

	      Causes execution to resume after the
		      of the nearest enclosing or 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
		      resuming after the

	      A	label in a
		      statement	as discussed below.

	      Change the shell's current working directory to
		      directory_name.  If not  specified,  directory_name  de-
		      faults to	your home directory.
		      If  directory_name is not	found as a subdirectory	of the
		      current working directory	(and does not  begin  with  or
		      each  component of the variable cdpath is	checked	to see
		      if it has	a subdirectory	directory_name.	  Finally,  if
		      all  else	 fails,	treats directory_name as a shell vari-
		      able.  If	its value begins with this is tried to see  if
		      it is a directory.  See also cd(1).

	      Continue execution of the	nearest	enclosing
		      or The rest of the commands on the current line are exe-

	      Labels the default case in a
		      statement.  The default should come after	all other  la-

	      Prints the directory stack; the top of the stack is at the left;
		      the  first  directory in the stack is the	current	direc-

	      The specified words are written to the shell's standard output,
		      separated	by spaces, and terminated with a new-line  un-
		      less the option is specified.  See also echo(1).

	      See the descriptions of the
		      and statements below.

	      (Same behavior as
		      sh(1).)	arguments  are	read as	input to the shell and
		      the resulting command(s) executed.  This is usually used
		      to  execute  commands generated as the result of command
		      or variable substitution,	since  parsing	occurs	before
		      these substitutions.

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

	      exits either with	the value of the
		      variable (first form) or with the	value of the specified
		      expression (second form).

	      Brings the current
		      (job not specified) or specified	jobs  into  the	 fore-
		      ground, continuing them if they were stopped.

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

		      The built-in command can be used to  continue  the  loop
		      prematurely; the built-in	command	to terminate it	prema-
		      turely.  When this command is read  from	the  terminal,
		      the  loop	is read	once, prompting	with before any	state-
		      ments in the loop	are executed.  If you make  a  mistake
		      while typing in a	loop at	the terminal, use the erase or
		      line-kill	character as appropriate to recover.

	      Like    but no escapes are recognized and	words are delimited by
		      null  characters in the output.  Useful in programs that
		      use the shell to perform file name expansion on  a  list
		      of words.

	      The specified
		      word is file name	and command expanded to	yield a	string
		      of the form The shell rewinds its	input as much as  pos-
		      sible  and searches for a	line of	the form possibly pre-
		      ceded by blanks or tabs.	Execution continues after  the
		      specified	line.

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

	      Displays the history event list.
		      If  n  is	 given,	 only  the  n  most  recent events are
		      printed.	The option reverses the	order of  printout  to
		      be  most recent first rather than	oldest first.  The op-
		      tion prints the history list without leading numbers for
		      producing	files suitable for the command.

	      If      expression evaluates true, the single command with argu-
		      ments is executed.   Variable  substitution  on  command
		      happens  early, at the same time it does for the rest of
		      the command.  command must be a simple  command;	not  a
		      pipeline,	 a command list, a parenthesized command list,
		      or an aliased command.  Input/output redirection	occurs
		      even if expression is false, meaning that	command	is ex-
		      ecuted (this is a	bug).

	      If      expression1 is true, all commands	down to	the first  are
		      executed;	otherwise if expression2 is true, all commands
		      from the first down to the  second  are  executed,  etc.
		      Any  number  of  pairs  are  possible,  but  only	one is
		      needed.  The part	is likewise optional.  (The words  and
		      must  appear  at the beginning of	input lines.  The must
		      appear alone on its input	line or	after an

	      Lists active jobs.
		      The option lists process IDs in addition	to  the	 usual

	      Sends either the
		      TERM  (terminate)	 signal	or the specified signal	to the
		      specified	jobs or	processes.  Signals are	 either	 given
		      by  number or by names (as given in stripped of the pre-
		      fix (see signal(2)).  The	signal	names  are  listed  by
		      There  is	no default, so used alone does not send	a sig-
		      nal to the current job.  If the  signal  being  sent  is
		      TERM  (terminate)	or HUP (hangup), the job or process is
		      sent  a  CONT  (continue)	 signal	 as  well.   See  also

	      Limits the usage by the current process and each process
		      it  creates  not to (individually) exceed	maximum_use on
		      the specified resource.  If maximum_use  is  not	speci-
		      fied,  then  the current limit is	displayed; if resource
		      is not specified,	then all limitations are given.

		      If the flag is specified,	the hard limits	are  used  in-
		      stead  of	 the current limits.  The hard limits impose a
		      ceiling on the values of the current limits.   Only  the
		      superuser	 can  raise  the  hard	limits,	but a user can
		      lower or raise  the  current  limits  within  the	 legal

		      Controllable resources currently include:

			   Maximum address space in bytes for a	process

			   Size	of the largest core dump that is created

			   Maximum  number  of	CPU seconds to be used by each

			   Maximum growth of the data region allowed
					       beyond the end of  the  program

			   Maximum number of open files	for each process

			   Largest single file that can	be created

			   Maximum size	to which a process's resident set size
			   can grow

			   Maximum size	of the	automatically  extended	 stack

		      The maximum_use argument can be specified	as a floating-
		      point or integer number followed by a scale factor: k or
		      kilobytes	 (1024	bytes),	m or megabytes,	or b or	blocks
		      (the units used by the ulimit system  call).   For  both
		      resource	names  and scale factors, unambiguous prefixes
		      of the names can be used.	 filesize can be lowered by an
		      instance	of  csh, but can only be raised	by an instance
		      whose effective user ID is root.	For more  information,
		      refer to the documentation for the ulimit	system call.

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

	      Terminates a login shell.
		      Especially useful	if ignoreeof is	set.  A	similar	 func-
		      tion,  which  works  for	sessions  that	are  not login
		      shells, is provided for historical reasons.  Its use  is
		      not  recommended	because	it is not part of the standard
		      BSD and may not be supported in future releases.

	      Changes the group	identification of the caller; for details see
		      newgrp(1).  A new	shell is executed by so	that the  cur-
		      rent shell environment is	lost.

	      The first	form sets the
		      nice (run	command	priority) for this shell to 4 (the de-
		      fault).  The second form sets the	priority to the	 given
		      number.	The  final two forms run command at priority 4
		      and number  respectively.	  The  user  with  appropriate
		      privileges can raise the priority	by specifying negative
		      niceness using command is	 always	 executed  in  a  sub-
		      shell,  and  restrictions	 placed	 on commands in	simple
		      statements apply.	 See also nice(1).

	      Without an argument,
		      can be used in shell scripts to cause hangups to be  ig-
		      nored  for  the  remainder of the	script.	 With an argu-
		      ment, causes  the	 specified  command  to	 be  run  with
		      hangups  ignored.	  All  processes executed in the back-
		      ground with are effectively as described under  Jobs  in
		      the COMMANDS section.

	      Causes the shell to notify the user asynchronously when the sta-
	      tus of the
		      current (job not specified) or specified	jobs  changes;
		      normally	notification  is  presented  before  a prompt.
		      This is automatic	if the shell variable notify is	set.

	      Controls the action of the shell on interrupts.
		      With no arguments, onintr	restores the default action of
		      the  shell  on  interrupts, which	action is to terminate
		      shell scripts or return to the  terminal	command	 input
		      level.  If is specified, all interrupts are ignored.  If
		      a	label is given,	the shell executes a when an interrupt
		      is received or a child process terminates	because	it was

		      If the shell is running in the background	and interrupts
		      are being	ignored, onintr	has no effect; interrupts con-
		      tinue to be ignored by the shell and  all	 invoked  com-

	      Pops the directory stack,	returning to the new top directory.
		      With  an	argument, discards the nth entry in the	stack.
		      The elements of the directory stack are numbered from  0
		      starting	at  the	top.  A	synonym	for called is provided
		      for historical reasons.  Its use is not recommended  be-
		      cause  it	is not part of the standard BSD	and may	not be
		      supported	in future releases.

	      With no arguments,
		      pushd exchanges the top two elements  of	the  directory
		      stack.   Given a name argument, pushd changes to the new
		      directory	(using cd) and pushes the old current  working
		      directory	 (as in	csw) onto the directory	stack.	With a
		      numeric argument,	pushd rotates the nth argument of  the
		      directory	stack around to	be the top element and changes
		      to that directory.  The members of the  directory	 stack
		      are  numbered from the top starting at 0.	 A synonym for
		      pushd, called gd,	is provided  for  historical  reasons.
		      Its  use	is not recommended since it is not part	of the
		      standard BSD and may not	be  supported  in  future  re-

	      Causes  the  internal hash table of the contents of the directo-
	      ries in the
		      path variable to be recomputed.  This is needed  if  new
		      commands	are added to directories in 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 di-

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

	      The first	form of
		      shows the	value of all shell variables.  Variables whose
		      value  is	 other than a single word print	as a parenthe-
		      sized 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 indexth 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	can be repeated	to set multiple	values
		      in a single set command.	Note, however,	that  variable
		      expansion	 happens  for all arguments before any setting

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

	      If no argument is	given, the members of
		      are  shifted  to the left, discarding An error occurs if
		      is not set or has	less than two strings assigned to  it.
		      When  variable  is  specified,  shift  performs the same
		      function on the specified	variable.

	      reads commands from
		      name.  commands can be nested, but if nested too	deeply
		      the  shell may run out of	file descriptors.  An error in
		      a	at any level terminates	 all  nested  commands.	  Nor-
		      mally,  input  during commands is	not placed on the his-
		      tory list.  The option can be used to place commands  in
		      the history list without being executing them.

	      Stops  the  current (no argument)	or specified jobs executing in
	      the background.

	      Causes  to stop as if it had been	sent a suspend signal.	 Since
		      normally	ignores	 suspend signals, this is the only way
		      to suspend the shell.  This command gives	an error  mes-
		      sage if attempted	from a login shell.

	      Each    label  (str1) is successively matched against the	speci-
		      fied string which	is first command  and  file  name  ex-
		      panded.	The form of the	labels is the Pattern Matching
		      Notation with the	exception that non-matching  lists  in
		      bracket  expressions  are	not supported (see regexp(5)).
		      If none of the labels match before a label is found, the
		      execution	 begins	 after	the label.  Each label and the
		      label must appear	at the beginning of a line.  The  com-
		      mand causes execution to continue	after the endsw.  Oth-
		      erwise, control may fall through labels and labels as in
		      C.   If no label matches and there is no default,	execu-
		      tion continues after the

	      When    command is not specified,	a summary of time used by this
		      shell  and  its  children	is printed.  If	specified, the
		      simple command is	timed and a time summary as  described
		      under  the  variable is printed.	If necessary, an extra
		      shell is created to print	the time  statistic  when  the
		      command completes.

	      The current file creation	mask is	displayed
		      (value  not  specified)  or  set to the specified	value.
		      The mask is given	in octal.  Common values for the  mask
		      are  which  gives	all permissions	to the owner and group
		      and read and execute permissions to all others, or which
		      gives  all  permissions  to the owner, and only read and
		      execute permission to the	group  and  all	 others.   See
		      also umask(1).

	      All aliases whose	names match the	specified
		      pattern are discarded.  Thus, all	aliases	are removed by
		      No error occurs if pattern does not  match  an  existing

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

	      All variables whose names	match the specified
		      pattern are removed.  Thus, all variables	are removed by
		      this has noticeably undesirable side-effects.  No	 error
		      occurs if	pattern	matches	nothing.

	      Removes all variables whose names	match the specified
		      pattern  from  the  environment.	 See  also the command
		      above and	printenv(1).

	      Waits for	all background jobs to terminate.
		      If the shell is interactive, an  interrupt  can  disrupt
		      the  wait,  at which time	the shell prints names and job
		      numbers of all jobs known	to be outstanding.

	      While the	specified
		      expression evaluates non-zero, the commands between  the
		      and the matching are evaluated.  and can be used to ter-
		      minate or	continue the loop prematurely.	(The and  must
		      appear  alone  on	their input lines.)  If	the input is a
		      terminal (i.e., not  a  script),	prompting  occurs  the
		      first time through the loop as for the statement.

	      Brings the specified job into the	foreground.

	      Continues	the specified job in the background.

				    The	 first	form  prints the values	of all
				    the	shell variables.
		      The second form sets the specified name to the value  of
		      expression.  If the expression contains or at least this
		      part of the expression must be placed  within  parenthe-
		      ses.   The third form assigns the	value of expression to
		      the indexth argument of name.  Both name and its indexth
		      component	must already exist.

		      The  operators etc., are available as in C.  White space
		      can optionally separate the name from the	assignment op-
		      erator.	However,  spaces  are  mandatory in separating
		      components of expression which would otherwise be	single

		      Special  postfix	and  operators increment and decrement
		      name, respectively (e.g.,

   Non-Built-In	Command	Execution
       When a command to be executed is	not a built-in	command,  attempts  to
       execute	the command via	exec(2).  Each word in the variable path names
       a directory in which the	shell attempts to find	the  command  (if  the
       command	does  not begin	with If	neither	nor is given, the shell	hashes
       the names in these directories into an internal table so	that  an  exec
       is attempted only in those directories where the	command	might possibly
       reside.	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 or if or	was given, or if any  directory	 component  of
       path  does  not	begin with a the shell concatenates the	directory name
       and the given command name to form a path name of a file	which it  then
       attempts	to execute.

       Commands	 placed	 inside	parentheses are	always executed	in a subshell.

       prints the home directory then returns to the  current  directory  upon
       completion, whereas:

       remains in the home directory upon completion.

       When  commands  are placed inside parentheses, it is usually to prevent
       chdir from affecting the	current	shell.

       If the file has execute permissions but is  not	an  executable	binary
       file, it	is assumed to be a script file,	which is a file	of data	for an
       interpreter that	is executed as a separate process.

       first attempts to load and execute the script file (see	exec(2)).   If
       the  first two characters of the	script file are	exec(2)	expects	an in-
       terpreter path name to follow and attempts to execute the specified in-
       terpreter as a separate process to read the entire script file.

       If  no  is named, and there is an alias for the shell, the words	of the
       alias are inserted at the beginning of the argument list	 to  form  the
       shell  command.	 The  first  word of the alias should be the full path
       name of the command to be used.	Note that this is a special,  late-oc-
       curring	case of	alias substitution, which inserts words	into the argu-
       ment list without modification.

       If no is	named and there	is no shell alias, but the first character  of
       the  file  is  the  interpreter named by	the variable is	executed (note
       that this normally would	be unless the user has reset If	is not set, is

       If no is	named, and there is no shell alias, and	the first character of
       the file	is not is executed to interpret	the script file.

   History Substitutions
       History substitutions enable you	to repeat  commands,  use  words  from
       previous	 commands  as  portions	of new commands, repeat	arguments of a
       previous	command	in the current command,	and  fix  spelling  or	typing
       mistakes	in an earlier command.

       History substitutions begin with	an exclamation point Substitutions can
       begin anywhere in the input stream, but cannot be nested.  The exclama-
       tion  point  can	be preceded by a backslash to cancel its special mean-
       ing.  For convenience, an exclamation point is passed to	the parser un-
       changed	when  it  is followed by a blank, tab, newline,	equal sign, or
       left parenthesis.  Any input line that contains history substitution is
       echoed on the terminal before it	is executed for	verification.

       Commands	 input from the	terminal that consist of one or	more words are
       saved on	the history list.  The history substitutions  reintroduce  se-
       quences	of words from these saved commands into	the input stream.  The
       number of previous commands saved is controlled by the  variable.   The
       previous	 command  is  always saved, regardless of its value.  Commands
       are numbered sequentially from 1.

       You can refer to	previous events	by event number	 (such	as  for	 event
       10),  relative  event location (such as for the second previous event),
       full or partial command name (such as for the last event	using  a  com-
       mand with initial character and string expression (such as referring to
       an event	containing the characters

       These forms, without further modification, simply reintroduce the words
       of  the	specified events, each separated by a single blank.  As	a spe-
       cial case, is a re-do; it refers	to the previous	command.

       To select words from a command, use a colon and a  designator  for  the
       desired	words  after  the  event specification.	 The words of an input
       line are	numbered from zero.  The basic word designators	are:

	      First word (i.e.,	the command name itself).

	      n	   nth word.

	      First argument.
		   (This is equivalent to

	      Last word.

	      Range of words from
		   a through b.	 Special cases are an abbreviation for	``word
		   0 through word y''; and which means ``word x	up to, but not
		   including, word

	      Range from the second word through the last word.

	      Used with	a search sequence
		   to substitute the immediately preceding matching word.

       The colon separating the	command	specification from the word designator
       can be omitted if the argument selector begins with a or

       After  word designator can be followed by a sequence of modifiers, each
       preceded	by a colon.  The following modifiers are defined:

	      Use only the first component of a	path name
		   by removing all following components.

	      Use the root file	name by	removing any trailing suffix (.xxx).

	      Use the file name's trailing suffix
		   by removing the root	name.

	      substitute the value of
		   r for the value l in	the indicated command.

	      Use only the final file name of a	path name by removing all
		   leading path	name components.

	      Repeat the previous substitution.

	      Print the	new command but	do not execute it.

	      Quote the	substituted words, preventing further substitutions.

	      Like but break into words	at blanks, tabs	and newlines.

	      Use a
		   command as a	prefix to another modifier to cause the	speci-
		   fied	 change	to be made globally.  All words	in the command
		   are changed,	one change per word, and each string  enclosed
		   in  single  quotes  or double quotes	is treated as a	single

       Unless preceded by a the	modification is	applied	only to	the first mod-
       ifiable word.  An error results if a substitution is attempted and can-
       not be completed	(i.e., if you ask for a	substitution of	on  a  history
       buffer containing only 10 commands).

       The  left  hand	side of	substitutions are strings; not regular expres-
       sions in	the sense of HP-UX editors.  Any character can be used as  the
       delimiter  in  place of a slash (/).  Use a backslash to	quote a	delim-
       iter character if it is used in the l or	r string.   The	 character  in
       the  right-hand	side  is  replaced  by the text	from the left.	A also
       quotes A	null l string uses the previous	string either  from  an	 l  or
       from  a	contextual scan	string s in The	trailing delimiter in the sub-
       stitution can be	omitted	if a new-line character	 follows  immediately,
       as may the trailing in a	contextual scan.

       A  history reference can	be given without an event specification	(as in
       In this case, the reference is to the previous command unless a	previ-
       ous  history  reference	occurred  on the same line, in which case this
       form repeats the	previous reference.  Thus

       gives the first and last	arguments from the command matching

       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 providing a convenient shorthand for substitutions	on the
       text  of	the previous line.  Thus fixes the spelling of in the previous

       Finally,	a history substitution can be enclosed within curly braces  if
       necessary to insulate it	from the characters which follow.  Thus, after

       one could execute to do

       while would look	for a command starting with

   Quoting with	Single and Double Quotes
       The  quotation of strings by single quotes (') and double quotes	can be
       used to prevent all or some of the  remaining  substitutions.   Strings
       enclosed	 in  single  quotes are	protected from any further interpreta-
       tion.  Strings enclosed in double quotes	are still variable-  and  com-
       mand-expanded as	described below.

       In  both	 cases	the  resulting	text becomes (all or part of) a	single
       word.  Only in one special case (see below) does	a double-quoted	string
       yield parts of more than	one word; single-quoted	strings	never do.

   Alias Substitution
       maintains  a  list  of  aliases that can	be established,	displayed, and
       modified	by the and commands.  After a command line is scanned,	it  is
       parsed into distinct commands and the first word	of each	command, left-
       to-right, is checked to see if it has an	alias.	If it does,  the  text
       which  is  the alias for	that command is	reread with the	history	mecha-
       nism available as if that command was the previous input	line.  The re-
       sulting	words  replace the command and argument	list.  If no reference
       is made to the history list, the	argument list is left unchanged.

       Thus, if	the alias for is the command maps to leaving the argument list
       undisturbed.  Similarly,	if the alias for was maps to

       If an alias is found, the word transformation of	the input text is per-
       formed and the aliasing process begins again  on	 the  re-formed	 input
       line.   Looping	is  prevented if the first word	of the new text	is the
       same as the old by flagging it  to  prevent  further  aliasing.	 Other
       loops are detected and cause an error.

       Note  that the mechanism	allows aliases to introduce parser metasyntax.

       makes a command that uses pr(1) to print	 its  arguments	 on  the  line

       Some  of	 the built-in commands take expressions	in which the operators
       are similar to those of C, with the same	precedence.  These expressions
       appear  in  the	and  commands.	 The following operators are available
       (shown in order of increasing precedence):

       The following list shows	the grouping of	these operators.   The	prece-
       dence decreases from top	to bottom in the list:

       The  operators and compare their	arguments as strings; all others oper-
       ate on numbers.	The operators and are similar to and except  that  the
       right-hand side is a pattern (containing	and instances of against which
       the left	hand operand is	matched.  This reduces the need	for use	of the
       statement  in  shell  scripts when all that is really needed is pattern

       Strings beginning with are considered octal numbers.  Null  or  missing
       arguments are considered	The result of all expressions are strings that
       represent decimal numbers.  It is important to note that	no two	compo-
       nents  of  an expression	can appear in the same word.  These components
       should be surrounded by spaces except when adjacent  to	components  of
       expressions that	are syntactically significant to the parser: and

       Also  available in expressions as primitive operands are	command	execu-
       tions enclosed in curly braces and file enquiries of the	form  where  l
       is one of:

	      read access
	      write access
	      execute access
	      zero size
	      plain file

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

   Control of the Flow
       contains	 a number of commands that 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 parts of	its input and, due to the  implementa-
       tion, restrict the placement of some of the commands.

       The  and	 statements, as	well as	the form of the	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	input whenever
       a loop is being read and	performs seeks in this internal	buffer to  ac-
       complish	 the  rereading	implied	by the loop.  (To the extent that this
       allows, backward	succeed	on non-seekable	inputs.)

   Signal Handling
       normally	ignores	quit signals.  Jobs running in background mode are im-
       mune  to	signals	generated from the keyboard, including hangups.	 Other
       signals have the	values which the  shell	 inherited  from  its  parent.
       handling	 of  interrupts	 and terminate signals in shell	scripts	can be
       controlled by onintr.  Login shells catch the terminate signal;	other-
       wise 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	 read-
       ing the file

   Command Line	Parsing
       splits input lines into words at	blanks and tabs.  The following	excep-
       tions (parser metacharacters) are considered separate words:

	      vertical bar;
	      less-than	sign;
	      greater-than sign;
	      left parenthesis;
	      right parenthesis;
	      double ampersand;
	      double vertical bar;
	      double less-than sign;
	      double greater-than sign;
	      comment delimiter

       The backslash removes the special meaning of these  parser  metacharac-
       ters.  A	parser metacharacter preceded by a backslash is	interpreted as
       its ASCII value.	 A newline character (ASCII 10)	preceded  by  a	 back-
       slash is	equivalent to a	blank.

       Strings	enclosed  in  single  or  double  quotes form parts of a word.
       Metacharacters in these strings,	including blanks and tabs, do not form
       separate	 words.	 Within	pairs of backslashes or	quotes,	a newline pre-
       ceded by	a backslash gives a true newline character.

       When input is not a terminal, the character introduces a	comment	termi-
       nated by	a newline.

       maintains  a set	of variables.  Each variable has a value equal to zero
       or more strings (words).	 Variables have	names consisting of up	to  80
       letters and digits starting with	a letter.  The underscore character is
       considered a letter.  The value of a  variable  may  be	displayed  and
       changed	by using the and commands.  Some of the	variables are Boolean,
       that is,	the shell does not care	what their value is, only whether they
       are set or not.

       Some  operations	treat variables	numerically.  The at sign command per-
       mits numeric calculations to be performed and the result	assigned to  a
       variable.  The null string is considered	to be zero, and	any subsequent
       words of	multi-word values are ignored.

       After the input line is aliased and parsed, and before each command  is
       executed,  variable  expansion  is  performed  keyed by the dollar sign
       Variable	expansion can be prevented by preceding	the dollar sign	with a
       backslash  character except within double quotes	where substitution oc-
       curs.  Variables	are never  expanded  if	 enclosed  in  single  quotes.
       Strings	quoted by single quotes	are interpreted	later (see so variable
       substitution does not occur there until later, if  at  all.   A	dollar
       sign 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  en-
       tire argument list are expanded together.

       Unless  enclosed	in double quotes or given the modifier,	the results of
       variable	substitution may eventually be command and file	 name  substi-
       tuted.  Within double quotes, a variable	whose value consists of	multi-
       ple words expands to a portion of a single word,	with the words of  the
       variable's  value separated by blanks.  When the	modifier is applied to
       a substitution, the variable expands to multiple	words with  each  word
       separated  by  a	blank and quoted to prevent later command or file name

       The following metasequences are provided	for introducing	variable  val-
       ues into	the shell input.  Except as noted, it is an error to reference
       a variable that is not set.

	      When interpreted,	this sequence is replaced
		   by the words	of the value of	 the  variable	variable_name,
		   each	 separated  by a blank.	 Braces	insulate variable_name
		   from	subsequent characters that would otherwise  be	inter-
		   preted to be	part of	the variable name itself.
		   If variable_name is not a variable, but is set in the envi-
		   ronment, that value is used.	 variables cannot be  modified
		   as shown below.
	      This  modification selects only some of the words	from the value
		   variable_name.  The selector	is subjected to	variable  sub-
		   stitution,  and  can	consist	of a single number or two num-
		   bers	separated by a dash.  The first	word of	 a  variable's
		   value is numbered If	the first number of a range is omitted
		   it defaults to If the last member of	a range	is omitted  it
		   defaults  to	 the  total number of words in the variable An
		   asterisk metacharacter  used	 as  a	selector  selects  all

	      This form	gives the number of words in the variable,
		   and is useful for forms using a [selector] option.

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

	      This form	is equivalent to an indexed selection from  the	 vari-

	      This is equivalent to selecting all of

       The  modifiers and can be applied to the	substitutions above, as	can CR
       :gh , CR	:gt , and CR :gr .  If curly  braces  appear  in  the  command
       form,  the modifiers must appear	within the braces.  The	current	imple-
       mentation allows	only one modifier on each expansion.

       The following substitutions cannot be modified with modifiers:

	      Substitutes the string
		   if variable_name is set, if it is not.

		   if the current input	file name is known, if it is not.

	      Substitutes 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.

   Pre-Defined and Environment Variables
       The  following  variables  have special meaning to the shell.  Of these
       and are always set by the shell.	 Except	for and	 this  setting	occurs
       only  at	 initialization	 (initial execution of These variables are not
       modified	unless modified	explicitly by the user.

       copies the HP-UX	environment variable USER into the shell variable  the
       environment variable into the environment variable into and into	copies
       these values back into the environment whenever the variables  are  re-

       In a windowed environment, if detects that the window has changed size,
       sets the	environment variables and to match the new window size.

	      This variable is set to the arguments of the
			     command statement.	 It is from this variable that
			     positional	 parameters  are substituted; i.e., is
			     replaced by etc.

	      This variable gives a list of alternate directories searched
			     to	find subdirectories in chdir commands.

	      This variable contains the absolute path name
			     of	 the  current  working	directory.    Whenever
			     changing directories (using cd), this variable is

	      This variable is set by the
			     command line option.  If set, all	built-in  com-
			     mands and their arguments are echoed to the stan-
			     dard output device	just  before  being  executed.
			     Built-in  commands	 are echoed before command and
			     file name substitution, since these substitutions
			     are then done selectively.	 For non-built-in com-
			     mands, all	expansions occur before	echoing.

	      This variable is used to create the command history buffer
			     and to set	its size.  If  this  variable  is  not
			     set, no command history is	maintained and history
			     substitutions cannot be made.  Very large	values
			     of	can cause shell	memory overflow.  Values of 10
			     or	20 are normal.	All  commands,	executable  or
			     not, are saved in the command history buffer.

	      This  variable  contains the absolute path name to your home di-
			     The variable is initialized from the HP-UX	 envi-
			     ronment.	File name expansion of tilde refers to
			     this variable.

	      If set,	     ignores end-of-file characters from input devices
			     that  are	terminals.  exits normally when	it en-
			     counters the end-of-file condition	typed  as  the
			     first  character on a command line).  Setting ig-
			     noreeof prevents the  current  shell  from	 being
			     killed  by	 an  accidental	However, to prevent an
			     infinite loop of EOF input, terminates if it  re-
			     ceives 26 consecutive EOFs.

	      This variable contains a list of the files where
			     checks  for  your mail.  periodically (default is
			     10	minutes) checks	this variable before producing
			     a	prompt	upon command completion.  If the vari-
			     able contains a file name that has	been  modified
			     since  the	 last check (resulting from mail being
			     put in the	file), prints

			     If	the first word of the  value  of  is  numeric,
			     that  number  specifies a different mail checking
			     interval in seconds.

			     If	multiple mail files are	specified,  the	 shell
			     says  file_name, where file_name is the file con-
			     taining the mail.

	      This variable places restrictions	on output redirection
			     to	ensure that files  are	not  accidentally  de-
			     stroyed, and that commands	using append redirect-
			     ion refer to existing files.

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

	      If set, it is no longer an error
			     for a file	name expansion to not match any	exist-
			     ing files.	 If there is no	match,	the  primitive
			     pattern  is  returned.   It is still an error for
			     the primitive pattern to be malformed.  For exam-
			     ple, still	gives an error.

	      If set,	     notifies  you  immediately	(through your standard
			     output device)  of	 background  job  completions.
			     The default is (indicate job completions just be-
			     fore printing a prompt).

	      Each word	of the path variable specifies a directory
			     in	which commands are to be sought	for execution.
			     A null word specifies your	current	working	direc-
			     tory.  If there is	no path	 variable,  only  full
			     path names	can be executed.  When path is not set
			     and when users do not specify  full  path	names,
			     searches  for the command through the directories
			     (current directory) and A which is	given  neither
			     the  nor  the option normally hashes the contents
			     of	the directories	in the variable	after  reading
			     and each time the variable	is reset.  If new com-
			     mands are added to	these  directories  while  the
			     shell  is	active,	it is necessary	to execute for
			     to	access these new commands.

	      This variable lets you select your own prompt character string.
			     The prompt	is printed before each command is read
			     from an interactive terminal input.  If a appears
			     in	the string, it is replaced by the current com-
			     mand history buffer event number unless a preced-
			     ing is given.  The	default	prompt is the  percent
			     sign  for	users and the character	for the	super-

	      The number of lines from the history list	that are saved
			     in	when the user logs out.	Large values for  slow
			     down the during startup.

	      This variable contains the name of the file in which the
			     program  resides.	This variable is used in fork-
			     ing shells	to interpret files that	have their ex-
			     ecute  bits  set  but which are not executable by
			     the system.  (See the description of

	      This variable contains the status	value  returned	 by  the  last
			     If	 the  command  terminated  abnormally, 0200 is
			     added to the status variable's  value.   Built-in
			     commands  which terminated	abnormally return exit
			     status and	all other built-in commands set	status

	      This variable contains a numeric value
			     that  controls  the automatic timing of commands.
			     If	set, prints, for any command taking more  than
			     the  specified  number  of	cpu seconds, a line of
			     information to the	standard output	device	giving
			     user,  system,  and  real	execution times	plus a
			     utilization percentage.  The utilization percent-
			     age  is  the  ratio  of user plus system times to
			     real time.	 This message  is  printed  after  the
			     command finishes execution.

	      This variable is set by the
			     command  line  option.  If	set, the words of each
			     command are printed on the	standard output	device
			     after history substitutions have been made.

   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 that 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 grave ac-
       cents (`	...`).	The output from	such a command is normally broken into
       separate	words at blanks, tabs and newlines, with null words being dis-
       carded; this text then replacing	the original  string.	Within	double
       quotes, only newlines force new words; blanks and tabs are preserved.

       In  any case, the single	final newline 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
       Each command word is processed as a pattern for file name substitution,
       also known as and replaced with a sorted	list of	file names which match
       the pattern.  The form of the patterns is the Pattern Matching Notation
       defined by regexp(5) with the following exceptions:

	      o	 Non-matching lists in bracket expressions are not supported.

	      o	 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.

	      o	 The metanotation a{b,c,d}e is a shorthand for "abe ace	 ade".
		 Left to right order is	preserved, with	results	of matches be-
		 ing sorted separately at a low	level to preserve this	order.
		 This construct	may be nested.	Thus:

		 expands to

		 whether or not	these files exist, without any chance of error
		 if the	home directory for is Similarly,

		 might expand to

		 (Note that was	not sorted with	the results of matching	 As  a
		 special case, and are passed undisturbed.

       The  standard  input and	standard output	of a command can be redirected
       with the	following syntax:

	      Open file	     name (which is first variable, command  and  file
			     name expanded) as the standard input.

	      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 substitu-
			     tion is performed on the intervening  lines,  al-
			     lowing  to	 quote and `.  Commands	which are sub-
			     stituted have all blanks, tabs, and newlines pre-
			     served,  except  for  the	final newline which is
			     dropped.  The resultant  text  is	placed	in  an
			     anonymous	temporary  file	 which is given	to the
			     command as	standard input.

	      The file	     name is used as standard  output.	 If  the  file
			     does  not	exist,	it is created; if the file ex-
			     ists, it is truncated, and	its previous  contents
			     are lost.

			     If	 the  variable is set, the file	must not exist
			     or	be a character special file (e.g., a  terminal
			     or	or an error results.  This helps prevent acci-
			     dental destruction	of files.  In  this  case  the
			     exclamation  point	 forms can be used to suppress
			     this check.

			     The forms involving the ampersand character route
			     the  standard  error  into	 the specified file as
			     well as the standard output.  name	is expanded in
			     the same way as < input file names	are.

	      Uses file	     name  as  standard	output the same	as but appends
			     output to the end of the file.  If	 the  variable
			     is	 set, it is an error for the file not to exist
			     unless one	of the forms is	given.	Otherwise,  it
			     is	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 command
       in  a  pipeline.	  Thus,	unlike some previous shells, commands executed
       from a shell script have	no access to the text of the commands  by  de-
       fault;  rather  they  receive the original standard input of the	shell.
       The mechanism should be used to	present	 inline	 data.	 This  permits
       shell  scripts  to  function  as	components of pipelines	and allows the
       shell to	block-read its input.

       Diagnostic output can be	directed through a pipe	with the standard out-
       put.  Simply use	the form rather	than by	itself.

   File	Name Completion
       In  typing  file	names as arguments to commands,	it is no longer	neces-
       sary to type a complete name, only a unique abbreviation	is  necessary.
       When  you  want the system to try to match your abbreviation, press the
       ESC key.	 The system then completes the file name for you, echoing  the
       full  name  on  your  terminal.	 If the	abbreviation does not match an
       available file name, the	terminal's bell	is sounded.  The file name may
       be partially completed if the prefix matches several longer file	names.
       In this case, the name is extended up to	the ambiguous  deviation,  and
       the bell	is sounded.

       File  name completion works equally well	when other directories are ad-
       dressed.	 In addition, the tilde	convention for home directories	is un-
       derstood	in this	context.

   Viewing a File or Directory List
       At  any	point  in  typing  a  command, you can request "what files are
       available" or "what files match my current specification".  Thus,  when
       you have	typed:

       you  may	 wish  to  know	what files or subdirectories exist (in without
       aborting	the command you	are typing.  Typing at this  point  lists  the
       files  available.   Files  are  listed in multicolumn format, sorted by
       column.	Directories and	executable files are identified	by a  trailing
       and  respectively.   Once  printed, the command is re-echoed for	you to
       complete.  Additionally,	you may	want to	know which files match a  pre-
       fix, the	current	file specification so far.  If you had typed:

       followed	 by a all files	and subdirectories whose prefix	was in the di-
       rectory would be	printed.  Notice that the example before was simply  a
       degenerate  case	 of  this  with	 a null	trailing file name.  (The null
       string is a prefix of all strings.)  Notice also	that a trailing	 slash
       is  required  to	pass to	a new sub-directory for	both file name comple-
       tion and	listing.  Note that the	degenerate case

       prints a	full list of login names on the	current	system.

   Command Name	Recognition
       Command name recognition	and completion works in	 the  same  manner  as
       file  name  recognition and completion above.  The current value	of the
       environment variable is used in searching for the command.  For example

       might expand to


       lists all commands (along that begin with As an option,	if  the	 shell
       variable	 is  set,  a number indicating the index in is printed next to
       each command on a [Control]-[D] listing.

       A new shell variable has	been added called If the terminal remains idle
       (no  character  input) at the shell's top level for a number of minutes
       greater than the	value assigned to you are  automatically  logged  off.
       The  feature is temporarily disabled while a command is executing.  The
       initial value of	is 600.	 If unset or set to 0, is entirely disabled.

   Command Line	Control
       A re-prints the current command line; erases the	last word  entered  on
       the current command line.

       C  shell	 restores your terminal	to a sane mode if it appears to	return
       from some command in raw, cbreak, or noecho mode.

   Saving Your History Buffer
       has the ability to save your history list between login	sessions.   If
       the  shell  variable  is	set to a number, that number of	command	events
       from your history list is saved.	 For example, placing the line

       in your file maintains a	history	buffer of length 10 and	saves the  en-
       tire  list when you logout.  When you log back in, the entire buffer is
       restored.  The commands are saved in the	file in	your login directory.

   Environment Variables
       LC_COLLATE determines the collating sequence used in evaluating pattern
       matching	notation for file name substitution.

       LC_CTYPE	 determines the	interpretation of text as single and/or	multi-
       byte characters,	the classification of characters as letters,  and  the
       characters  matched  by character class expressions in pattern matching

       LANG determines the language in which messages are displayed.

       If LC_COLLATE or	LC_CTYPE is not	specified in the environment or	is set
       to  the	empty  string, the value of LANG is used as a default for each
       unspecified or empty variable.  If LANG is not specified	or is  set  to
       the  empty  string,  a  default of "C" (see lang(5)) is used instead of
       LANG.  If any internationalization variable contains  an	 invalid  set-
       ting,  behaves as if all	internationalization variables are set to "C".
       See environ(5).

   International Code Set Support
       Single- and multi-byte character	code sets are supported.

       The file	should be structured such that it cannot generate  any	output
       on  standard  output  or	standard error,	including occasions when it is
       invoked without an affiliated terminal.	rcp(1) causes to  be  sourced,
       and  any	 output	 generated by this file, even to standard error	causes
       problems.  Commands such	as stty(1) should be placed in not in so  that
       their output cannot affect rcp(1).

       has  certain  limitations.   Words  or  environment variables can be no
       longer than 10240 characters.  The  system  limits  argument  lists  to
       10240  characters.  The number of arguments to a	command	which involves
       file name expansion is limited to one-sixth the	number	of  characters
       allowed	in  an argument	list.  Command substitutions may substitute no
       more characters than are	allowed	in an argument list.

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

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

       Shell built-in functions	are not	 stoppable/restartable.	  Command  se-
       quences	of  the	 form are also not handled gracefully when stopping is
       attempted.  If you interrupt the	shell then immediately	executes  This
       is  especially noticeable if this expansion results from	an It suffices
       to place	the sequence of	commands in parentheses	to  force  it  into  a
       subshell; i.e.,

       Because of the signal handling required by csh, interrupts are disabled
       just before a command is	executed, and restored as the  command	begins
       execution.   There may be a few seconds delay between when a command is
       given and when interrupts are recognized.

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

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

       Commands	within loops, prompted for by are not placed  in  the  history
       list.   Control structure should	be parsed rather than being recognized
       as built-in commands.  This would allow control commands	to  be	placed
       anywhere, to be combined	with and to be used with and metasyntax.

       It  should  be  possible	 to use	the modifiers on the output of command
       substitutions.  All and more than one modifier  should  be  allowed  on

       Terminal	type is	examined only the first	time you attempt recognition.

       To list all commands on the system along	enter [Space]-[Ctrl]-[D].

       The csh metasequence does not work.

       In  an  international  environment, character ordering is determined by
       the setting of LC_COLLATE, rather than by the binary ordering of	 char-
       acter  values  in  the machine collating	sequence.  This	brings with it
       certain attendant dangers, particularly when using range	expressions in
       file name generation patterns.  For example, the	command,

       might  be  expected  to match all file names beginning with a lowercase
       alphabetic character.  However, if dictionary ordering is specified  by
       LC_COLLATE,  it would also match	file names beginning with an uppercase
       character (as well as those beginning  with  accented  letters).	  Con-
       versely,	 it  would  fail  to match letters collated after in languages
       such as Norwegian.

       The correct (and	safe) way to match specific character  classes	in  an
       international environment is to use a pattern of	the form:

       This  uses to determine character classes and works predictably for all
       supported languages and codesets.  For shell scripts produced  on  non-
       internationalized  systems (or without consideration for	the above dan-
       gers), it is recommended	that they be executed in  a  non-NLS  environ-
       ment.  This requires that etc., be set to "C" or	not set	at all.

       implements  command  substitution by creating a pipe between itself and
       the command.  If	the root file system is	full, the substituted  command
       cannot  write  to  the  pipe.  As a result, the shell receives no input
       from the	command, and the result	of the substitution is null.  In  par-
       ticular,	 using command substitution for	variable assignment under such
       circumstances results in	the variable being silently  assigned  a  NULL

       Relative	path changes (such as when in a	symbolically linked directory,
       cause knowledge of the working directory	to be along the	symbolic  path
       instead of the physical path.

       Prior  to  HP-UX	Release	9.0, when getting its input from a file, would
       exit immediately	if unable to execute a command (such as	if it was  un-
       able  to	find the command).  Beginning at Release 9.0, continues	on and
       attempts	to execute the remaining commands in the  file.	  However,  if
       the  old	 behavior is desired for compatibility purposes, set the envi-
       ronment variable	to 1.

       was developed by	the University of California, Berkeley and HP.

       A csh script sourced (executed) at the beginning	of execution  by  each

       A csh script sourced (executed) by login	shell, after
				at login.

       A csh script sourced (executed) by login	shell, at logout.

       Source of home directories for

       Standard	shell, for shell scripts not starting with a

       A csh script sourced (executed) before
				and when starting a csh	login (analogous to in
				the POSIX shell).

       Temporary file for

       cd(1), echo(1), kill(1),	nice(1), sh(1),	umask(1), access(2),  exec(2),
       fork(2),	 pipe(2),  umask(2),  wait(2),	tty(7),	 a.out(4), environ(5),
       lang(5),	regexp(5).

       tutorial	in



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