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NetBSD 6.1.5 - man page for ksh (netbsd section 1)

KSH(1)					  User commands 				   KSH(1)

       ksh - Public domain Korn shell

       ksh [+-abCefhikmnprsuvxX] [+-o option] [ [ -c command-string [command-name] | -s | file ]
       [argument ...] ]

       ksh is a command interpreter that is intended for both interactive and shell  script  use.
       Its command language is a superset of the sh(1) shell language.

   Shell Startup
       The following options can be specified only on the command line:

       -c command-string
	      the shell executes the command(s) contained in command-string

       -i     interactive mode -- see below

       -l     login shell -- see below interactive mode -- see below

       -s     the  shell  reads  commands from standard input; all non-option arguments are posi-
	      tional parameters

       -r     restricted mode -- see below

       In addition to the above, the options described in the set built-in command  can  also  be
       used on the command line.

       If  neither  the -c nor the -s options are specified, the first non-option argument speci-
       fies the name of a file the shell reads commands from; if there are  no	non-option  argu-
       ments,  the  shell  reads  commands from standard input.  The name of the shell (i.e., the
       contents of the $0) parameter is determined as follows: if the -c option is used and there
       is  a non-option argument, it is used as the name; if commands are being read from a file,
       the file is used as the name; otherwise the name the shell was called with (i.e., argv[0])
       is used.

       A  shell  is  interactive  if the -i option is used or if both standard input and standard
       error are attached to a tty.  An interactive shell has job control enabled (if available),
       ignores	the  INT, QUIT and TERM signals, and prints prompts before reading input (see PS1
       and PS2 parameters).  For non-interactive shells, the trackall option  is  on  by  default
       (see set command below).

       A  shell  is restricted if the -r option is used or if either the basename of the name the
       shell is invoked with or the SHELL parameter match the pattern  *r*sh  (e.g.,  rsh,  rksh,
       rpdksh,	etc.).	The following restrictions come into effect after the shell processes any
       profile and $ENV files:
	 o    the cd command is disabled
	 o    the SHELL, ENV and PATH parameters can't be changed
	 o    command names can't be specified with absolute or relative paths
	 o    the -p option of the command built-in can't be used
	 o    redirections that create files can't be used (i.e., >, >|, >>, <>)

       A shell is privileged if the -p option is used or if the real user-id or group-id does not
       match  the  effective  user-id or group-id (see getuid(2), getgid(2)).  A privileged shell
       does not process $HOME/.profile nor the	ENV  parameter	(see  below),  instead	the  file
       /etc/suid_profile  is  processed.   Clearing the privileged option causes the shell to set
       its effective user-id (group-id) to its real user-id (group-id).

       If the basename of the name the shell is called with (i.e., argv[0]) starts with -  or  if
       the  -l	option	is used, the shell is assumed to be a login shell and the shell reads and
       executes the contents of /etc/profile, $HOME/.profile and $ENV if they exist and are read-

       If  the ENV parameter is set when the shell starts (or, in the case of login shells, after
       any profiles are processed), its value is subjected to parameter, command, arithmetic  and
       tilde  substitution  and  the  resulting  file  (if any) is read and executed.  If the ENV
       parameter is not set (and not null) the file $HOME/.kshrc is  included  (after  the  above
       mentioned substitutions have been performed).

       The  exit  status  of  the  shell is 127 if the command file specified on the command line
       could not be opened, or non-zero if a fatal syntax error occurred during the execution  of
       a  script.   In	the  absence of fatal errors, the exit status is that of the last command
       executed, or zero, if no command is executed.

   Command Syntax
       The shell begins parsing its input by breaking it into words.  Words, which are	sequences
       of  characters,	are delimited by unquoted white-space characters (space, tab and newline)
       or meta-characters (<, >, |, ;, &, ( and )).  Aside from delimiting words, spaces and tabs
       are  ignored,  while  newlines  usually delimit commands.  The meta-characters are used in
       building the following tokens: <, <&, <<, >, >&, >>, etc. are used to specify redirections
       (see  Input/Output Redirection below); | is used to create pipelines; |& is used to create
       co-processes (see Co-Processes below); ; is used to separate commands; & is used to create
       asynchronous pipelines; && and || are used to specify conditional execution; ;; is used in
       case statements; (( .. )) are used in arithmetic expressions; and lastly, ( .. ) are  used
       to create subshells.

       White-space  and  meta-characters  can  be  quoted individually using backslash (\), or in
       groups using double (") or single (') quotes.  Note that the following characters are also
       treated	specially by the shell and must be quoted if they are to represent themselves: \,
       ", ', #, $, `, ~, {, }, *, ? and [.  The first three of	these  are  the  above	mentioned
       quoting	characters (see Quoting below); #, if used at the beginning of a word, introduces
       a comment -- everything after the # up to the nearest newline is ignored;  $  is  used  to
       introduce  parameter,  command  and  arithmetic	substitutions (see Substitution below); `
       introduces an old-style command substitution (see Substitution below); ~ begins	a  direc-
       tory expansion (see Tilde Expansion below); { and } delimit csh(1) style alternations (see
       Brace Expansion below); and, finally, *, ? and [ are used in  file  name  generation  (see
       File Name Patterns below).

       As  words  and  tokens are parsed, the shell builds commands, of which there are two basic
       types: simple-commands, typically programs that are executed, and compound-commands,  such
       as for and if statements, grouping constructs and function definitions.

       A  simple-command  consists  of	some combination of parameter assignments (see Parameters
       below), input/output redirections  (see	Input/Output  Redirections  below),  and  command
       words;  the  only restriction is that parameter assignments come before any command words.
       The command words, if any, define the command that is to be executed  and  its  arguments.
       The  command  may  be a shell built-in command, a function or an external command, i.e., a
       separate executable file that is located using the PATH parameter (see  Command	Execution
       below).	Note that all command constructs have an exit status: for external commands, this
       is related to the status returned by wait(2) (if the command could not be found, the  exit
       status  is  127,  if it could not be executed, the exit status is 126); the exit status of
       other command constructs  (built-in  commands,  functions,  compound-commands,  pipelines,
       lists, etc.) are all well defined and are described where the construct is described.  The
       exit status of a command consisting only of parameter assignments is that of the last com-
       mand  substitution performed during the parameter assignment or zero if there were no com-
       mand substitutions.

       Commands can be chained together using the | token to form pipelines, in which  the  stan-
       dard  output  of each command but the last is piped (see pipe(2)) to the standard input of
       the following command.  The exit status of a pipeline is that  of  its  last  command.	A
       pipeline  may be prefixed by the ! reserved word which causes the exit status of the pipe-
       line to be logically complemented: if the original status was 0	the  complemented  status
       will be 1, and if the original status was not 0, then the complemented status will be 0.

       Lists  of  commands can be created by separating pipelines by any of the following tokens:
       &&, ||, &, |& and ;.  The first two are for conditional execution: cmd1 &&  cmd2  executes
       cmd2  only if the exit status of cmd1 is zero; || is the opposite -- cmd2 is executed only
       if the exit status of cmd1 is non-zero.	&& and || have equal precedence which  is  higher
       than  that  of &, |& and ;, which also have equal precedence.  The & token causes the pre-
       ceding command to be executed asynchronously, that is, the shell starts the  command,  but
       does  not wait for it to complete (the shell does keep track of the status of asynchronous
       commands -- see Job Control below).  When an asynchronous command is started when job con-
       trol is disabled (i.e., in most scripts), the command is started with signals INT and QUIT
       ignored and with input redirected from /dev/null (however, redirections specified  in  the
       asynchronous  command have precedence).	The |& operator starts a co-process which is spe-
       cial kind of asynchronous process (see Co-Processes below).  Note that a command must fol-
       low the && and || operators, while a command need not follow &, |& and ;.  The exit status
       of a list is that of the last command executed, with the exception of asynchronous  lists,
       for which the exit status is 0.

       Compound  commands  are created using the following reserved words -- these words are only
       recognized if they are unquoted and if they are used as the first word of a command (i.e.,
       they can't be preceded by parameter assignments or redirections):

				  case	 else	function   then    !
				  do	 esac	if	   time    [[
				  done	 fi	in	   until   {
				  elif	 for	select	   while   }
       Note: Some shells (but not this one) execute control structure commands in a subshell when
       one or more of their file descriptors are redirected, so any  environment  changes  inside
       them may fail.  To be portable, the exec statement should be used instead to redirect file
       descriptors before the control structure.

       In the following compound command descriptions, command lists (denoted as list)	that  are
       followed  by reserved words must end with a semi-colon, a newline or a (syntactically cor-
       rect) reserved word.  For example,
	      { echo foo; echo bar; }
	      { echo foo; echo bar<newline>}
	      { { echo foo; echo bar; } }
       are all valid, but
	      { echo foo; echo bar }
       is not.

       ( list )
	      Execute list in a subshell.  There is no implicit way to pass  environment  changes
	      from a subshell back to its parent.

       { list }
	      Compound construct; list is executed, but not in a subshell.  Note that { and } are
	      reserved words, not meta-characters.

       case word in [ [(] pattern [| pattern] ... ) list ;; ] ... esac
	      The case statement attempts to match word against the specified patterns; the  list
	      associated  with the first successfully matched pattern is executed.  Patterns used
	      in case statements are the same as those used for file name  patterns  except  that
	      the  restrictions  regarding  .  and  /  are dropped.  Note that any unquoted space
	      before and after a pattern is stripped; any space with a pattern	must  be  quoted.
	      Both  the  word  and the patterns are subject to parameter, command, and arithmetic
	      substitution as well as tilde substitution.  For historical reasons, open and close
	      braces  may be used instead of in and esac (e.g., case $foo { *) echo bar; }).  The
	      exit status of a case statement is that of the executed list; if no  list  is  exe-
	      cuted, the exit status is zero.

       for name [ in word ... term ] do list done
	      where  term  is either a newline or a ;.	For each word in the specified word list,
	      the parameter name is set to the word and list is executed.  If in is not  used  to
	      specify a word list, the positional parameters ("$1", "$2", etc.) are used instead.
	      For historical reasons, open and close braces may be used instead of  do	and  done
	      (e.g.,  for  i; { echo $i; }).  The exit status of a for statement is the last exit
	      status of list; if list is never executed, the exit status is zero.

       if list then list [elif list then list] ... [else list] fi
	      If the exit status of the first list is zero, the second list is	executed;  other-
	      wise  the  list  following the elif, if any, is executed with similar consequences.
	      If all the lists following the if and elifs fail (i.e., exit with non-zero status),
	      the  list  following  the  else is executed.  The exit status of an if statement is
	      that of non-conditional list that is executed; if no non-conditional list  is  exe-
	      cuted, the exit status is zero.

       select name [ in word ... term ] do list done
	      where  term is either a newline or a ;.  The select statement provides an automatic
	      method of presenting the user with a menu and selecting  from  it.   An  enumerated
	      list  of	the  specified	words  is printed on standard error, followed by a prompt
	      (PS3, normally `#? ').  A number corresponding to one of the  enumerated	words  is
	      then read from standard input, name is set to the selected word (or is unset if the
	      selection is not valid), REPLY is set to what was read (leading/trailing	space  is
	      stripped),  and  list is executed.  If a blank line (i.e., zero or more IFS charac-
	      ters) is entered, the menu is re-printed without executing list.	 When  list  com-
	      pletes,  the enumerated list is printed if REPLY is null, the prompt is printed and
	      so on.  This process is continues until an end-of-file is  read,	an  interrupt  is
	      received or a break statement is executed inside the loop.  If in word ... is omit-
	      ted, the positional parameters are used (i.e., "$1", "$2", etc.).   For  historical
	      reasons,	open and close braces may be used instead of do and done (e.g., select i;
	      { echo $i; }).  The exit status of a select statement is zero if a break	statement
	      is used to exit the loop, non-zero otherwise.

       until list do list done
	      This  works like while, except that the body is executed only while the exit status
	      of the first list is non-zero.

       while list do list done
	      A while is a prechecked loop.  Its body is executed as often as the exit status  of
	      the first list is zero.  The exit status of a while statement is the last exit sta-
	      tus of the list in the body of the loop; if the body is not executed, the exit sta-
	      tus is zero.

       function name { list }
	      Defines  the function name.  See Functions below.  Note that redirections specified
	      after a function definition are performed whenever the function  is  executed,  not
	      when the function definition is executed.

       name () command
	      Mostly the same as function.  See Functions below.

       time [ -p ] [ pipeline ]
	      The time reserved word is described in the Command Execution section.

       (( expression ))
	      The  arithmetic expression expression is evaluated; equivalent to let "expression".
	      See Arithmetic Expressions and the let command below.

       [[ expression ]]
	      Similar to the test and [ ... ] commands	(described  later),  with  the	following
		o    Field splitting and file name generation are not performed on arguments.
		o    The  -a  (and)  and  -o  (or) operators are replaced with && and ||, respec-
		o    Operators (e.g., -f, =, !, etc.) must be unquoted.
		o    The second operand of != and = expressions are patterns (e.g., the  compari-
		     son in
						  [[ foobar = f*r ]]
		o    There  are  two  additional  binary  operators: < and > which return true if
		     their first string operand is less  than,	or  greater  than,  their  second
		     string operand, respectively.
		o    The  single  argument form of test, which tests if the argument has non-zero
		     length, is not valid - explicit operators must always be used, e.g., instead
						       [ str ]
						     [[ -n str ]]
		o    Parameter, command and arithmetic substitutions are performed as expressions
		     are evaluated and lazy expression evaluation is used for the && and || oper-
		     ators.  This means that in the statement
					    [[ -r foo && $(< foo) = b*r ]]
		     the  $(<  foo)  is evaluated if and only if the file foo exists and is read-

       Quoting is used to prevent the shell from treating characters or words  specially.   There
       are three methods of quoting: First, \ quotes the following character, unless it is at the
       end of a line, in which case both the \ and the newline are stripped.   Second,	a  single
       quote  (')  quotes everything up to the next single quote (this may span lines).  Third, a
       double quote (") quotes all characters, except $, ` and \, up to the next unquoted  double
       quote.  $ and ` inside double quotes have their usual meaning (i.e., parameter, command or
       arithmetic substitution) except no field splitting is carried out on the results  of  dou-
       ble-quoted  substitutions.  If a \ inside a double-quoted string is followed by \, $, ` or
       ", it is replaced by the second character; if it is followed by a newline, both the \  and
       the newline are stripped; otherwise, both the \ and the character following are unchanged.

       Note:  An  earlier  version  of ksh(1) changed the interpretation of sequences of the form
       "...`...\"...`.."  according to whether or not POSIX mode was in effect.  In  the  current
       implementation,	the  backslash in \" is seen and removed by the outer "...", so the back-
       slash is not seen by the inner `...`.

       There are two types of aliases: normal  command	aliases  and  tracked  aliases.   Command
       aliases	are  normally  used  as a short hand for a long or often used command.	The shell
       expands command aliases (i.e., substitutes the alias name for its value) when it reads the
       first word of a command.  An expanded alias is re-processed to check for more aliases.  If
       a command alias ends in a space or tab, the following  word  is	also  checked  for  alias
       expansion.   The  alias expansion process stops when a word that is not an alias is found,
       when a quoted word is found or when an alias word that  is  currently  being  expanded  is

       The following command aliases are defined automatically by the shell:
	      autoload='typeset -fu'
	      functions='typeset -f'
	      hash='alias -t'
	      history='fc -l'
	      integer='typeset -i'
	      login='exec login'
	      nohup='nohup '
	      r='fc -e -'
	      stop='kill -STOP'
	      suspend='kill -STOP $$'
	      type='whence -v'

       Tracked	aliases  allow	the  shell  to remember where it found a particular command.  The
       first time the shell does a path search for a command that is marked as a  tracked  alias,
       it  saves  the full path of the command.  The next time the command is executed, the shell
       checks the saved path to see that it is still valid, and if so, avoids repeating the  path
       search.	Tracked aliases can be listed and created using alias -t.  Note that changing the
       PATH parameter clears the saved paths for all tracked aliases.  If the trackall option  is
       set  (i.e., set -o trackall or set -h), the shell tracks all commands.  This option is set
       automatically for non-interactive shells.  For interactive shells, only the following com-
       mands  are  automatically  tracked:  cat,  cc, chmod, cp, date, ed, emacs, grep, ls, mail,
       make, mv, pr, rm, sed, sh, vi and who.

       The first step the shell takes in executing a simple-command is to  perform  substitutions
       on  the	words  of the command.	There are three kinds of substitution: parameter, command
       and arithmetic.	Parameter substitutions, which are described in detail in the  next  sec-
       tion,  take  the  form  $name or ${...}; command substitutions take the form $(command) or
       `command`; and arithmetic substitutions take the form $((expression)).

       If a substitution appears outside of double quotes, the results of  the	substitution  are
       generally  subject  to  word  or field splitting according to the current value of the IFS
       parameter.  The IFS parameter specifies a list of characters which are  used  to  break	a
       string  up  into  several  words;  any characters from the set space, tab and newline that
       appear in the IFS characters are called IFS white space.  Sequences of  one  or	more  IFS
       white  space  characters,  in  combination with zero or one non-IFS white space characters
       delimit a field.  As a special case, leading and trailing  IFS  white  space  is  stripped
       (i.e.,  no  leading or trailing empty field is created by it); leading or trailing non-IFS
       white space does create an empty field.	 Example:  if  IFS  is	set  to  `<space>:',  the
       sequence  of  characters  `<space>A<space>:<space><space>B::D'  contains four fields: `A',
       `B', `' and `D'.  Note that if the IFS parameter is set	to  the  null  string,	no  field
       splitting  is done; if the parameter is unset, the default value of space, tab and newline
       is used.

       The results of substitution are, unless otherwise specified, also subject to brace  expan-
       sion and file name expansion (see the relevant sections below).

       A command substitution is replaced by the output generated by the specified command, which
       is run in a subshell.  For $(command) substitutions, normal quoting rules  are  used  when
       command	is  parsed,  however, for the `command` form, a \ followed by any of $, ` or \ is
       stripped (a \ followed by any other character is unchanged).  As a special case in command
       substitutions, a command of the form < file is interpreted to mean substitute the contents
       of file ($(< foo) has the same effect as $(cat foo), but it  is	carried  out  more  effi-
       ciently because no process is started).
       NOTE:  $(command)  expressions  are  currently parsed by finding the matching parenthesis,
       regardless of quoting.  This will hopefully be fixed soon.

       Arithmetic substitutions are replaced by the value of the specified expression.	For exam-
       ple,  the command echo $((2+3*4)) prints 14.  See Arithmetic Expressions for a description
       of an expression.

       Parameters are shell variables; they can be  assigned  values  and  their  values  can  be
       accessed  using	a  parameter substitution.  A parameter name is either one of the special
       single punctuation or digit character parameters described below, or a letter followed  by
       zero or more letters or digits (`_' counts as a letter).  The later form can be treated as
       arrays by appending an array index of the form: [expr] where expr is an arithmetic expres-
       sion.  Array indices are currently limited to the range 0 through 1023, inclusive.  Param-
       eter substitutions take the form $name, ${name} or ${name[expr]}, where name is a  parame-
       ter  name.   If	substitution  is performed on a parameter (or an array parameter element)
       that is not set, a null string is substituted unless the nounset option (set -o nounset or
       set -u) is set, in which case an error occurs.

       Parameters  can	be assigned values in a number of ways.  First, the shell implicitly sets
       some parameters like #, PWD, etc.; this is the  only  way  the  special	single	character
       parameters  are	set.   Second,	parameters  are  imported from the shell's environment at
       startup.  Third, parameters can be assigned values  on  the  command  line,  for  example,
       `FOO=bar'  sets the parameter FOO to bar; multiple parameter assignments can be given on a
       single command line and they can be followed  by  a  simple-command,  in  which	case  the
       assignments  are in effect only for the duration of the command (such assignments are also
       exported, see below for implications of this).  Note that both the parameter name and  the
       =  must	be unquoted for the shell to recognize a parameter assignment.	The fourth way of
       setting a parameter is with the export, readonly and typeset commands; see their  descrip-
       tions  in  the  Command	Execution section.  Fifth, for and select loops set parameters as
       well as the getopts, read and set -A commands.  Lastly, parameters can be assigned  values
       using  assignment  operators  inside  arithmetic  expressions  (see Arithmetic Expressions
       below) or using the ${name=value} form of parameter substitution (see below).

       Parameters with the export attribute (set using the export or typeset -x commands,  or  by
       parameter  assignments  followed by simple commands) are put in the environment (see envi-
       ron(7)) of commands run by the shell as name=value pairs.  The order in	which  parameters
       appear  in  the	environment  of  a  command is unspecified.  When the shell starts up, it
       extracts parameters and their values from  its  environment  and  automatically	sets  the
       export attribute for those parameters.

       Modifiers can be applied to the ${name} form of parameter substitution:

	      if name is set and not null, it is substituted, otherwise word is substituted.

	      if name is set and not null, word is substituted, otherwise nothing is substituted.

	      if  name	is set and not null, it is substituted, otherwise it is assigned word and
	      the resulting value of name is substituted.

	      if name is set and not null, it is substituted, otherwise word is printed on  stan-
	      dard error (preceded by name:) and an error occurs (normally causing termination of
	      a shell script, function or .-script).  If word is omitted  the  string  `parameter
	      null or not set' is used instead.

       In  the above modifiers, the : can be omitted, in which case the conditions only depend on
       name being set (as opposed to set and not null).  If word is needed,  parameter,  command,
       arithmetic  and	tilde  substitution are performed on it; if word is not needed, it is not

       The following forms of parameter substitution can also be used:

	      The number of positional parameters if name is *, @ or is  not  specified,  or  the
	      length of the string value of parameter name.

       ${#name[*]}, ${#name[@]}
	      The number of elements in the array name.

       ${name#pattern}, ${name##pattern}
	      If  pattern  matches the beginning of the value of parameter name, the matched text
	      is deleted from the result of substitution.  A single #  results	in  the  shortest
	      match, two #'s results in the longest match.

       ${name%pattern}, ${name%%pattern}
	      Like ${..#..} substitution, but it deletes from the end of the value.

       The  following  special	parameters  are  implicitly  set  by  the shell and cannot be set
       directly using assignments:

       !      Process id of the last background process started.  If no background processes have
	      been started, the parameter is not set.

       #      The number of positional parameters (i.e., $1, $2, etc.).

       $      The process ID of the shell, or the PID of the original shell if it is a subshell.

       -      The  concatenation  of the current single letter options (see set command below for
	      list of options).

       ?      The exit status of the last non-asynchronous command executed.  If the last command
	      was killed by a signal, $? is set to 128 plus the signal number.

       0      The  name the shell was invoked with (i.e., argv[0]), or the command-name if it was
	      invoked with the -c option and the command-name was supplied, or the file argument,
	      if  it was supplied.  If the posix option is not set, $0 is the name of the current
	      function or script.

       1 ... 9
	      The first nine positional parameters that were supplied to the shell,  function  or
	      .-script.  Further positional parameters may be accessed using ${number}.

       *      All positional parameters (except parameter 0), i.e., $1 $2 $3....  If used outside
	      of double quotes, parameters are separate words (which are subjected to word split-
	      ting);  if used within double quotes, parameters are separated by the first charac-
	      ter of the IFS parameter (or the empty string if IFS is null).

       @      Same as $*, unless it is used inside double quotes, in which case a  separate  word
	      is generated for each positional parameter - if there are no positional parameters,
	      no word is generated ("$@" can be used to access arguments, verbatim, without  los-
	      ing null arguments or splitting arguments with spaces).

       The following parameters are set and/or used by the shell:

       _ (underscore)
	      When  an	external  command  is executed by the shell, this parameter is set in the
	      environment of the new process to the path of the executed command.  In interactive
	      use,  this parameter is also set in the parent shell to the last word of the previ-
	      ous command.  When MAILPATH messages are evaluated,  this  parameter  contains  the
	      name of the file that changed (see MAILPATH parameter below).

       CDPATH Search  path  for  the  cd  built-in command.  Works the same way as PATH for those
	      directories not beginning with / in cd commands.	Note that if CDPATH  is  set  and
	      does not contain . nor an empty path, the current directory is not searched.

	      Set  to the number of columns on the terminal or window.	Currently set to the cols
	      value as reported by stty(1) if that value is non-zero.  This parameter is used  by
	      the  interactive	line editing modes, and by select, set -o and kill -l commands to
	      format information in columns.

       EDITOR If the VISUAL parameter is not set, this parameter controls the command line  edit-
	      ing mode for interactive shells.	See VISUAL parameter below for how this works.

       ENV    If  this	parameter  is  found  to be set after any profile files are executed, the
	      expanded value is used as a shell start-up file.	It  typically  contains  function
	      and alias definitions.

       ERRNO  Integer value of the shell's errno variable -- indicates the reason the last system
	      call failed.

	      Not implemented yet.

	      If set, this parameter is assumed to contain the shell that is to be used  to  exe-
	      cute  commands  that  execve(2)  fails to execute and which do not start with a `#!
	      shell' sequence.

       FCEDIT The editor used by the fc command (see below).

       FPATH  Like PATH, but used when an undefined function  is  executed  to	locate	the  file
	      defining	the  function.	 It  is also searched when a command can't be found using
	      PATH.  See Functions below for more information.

	      The name of the file used to store history.  When assigned to,  history  is  loaded
	      from  the  specified  file.   Also, several invocations of the shell running on the
	      same machine will share history if their HISTFILE parameters all point at the  same
	      NOTE:  if  HISTFILE isn't set, no history file is used.  This is different from the
	      original Korn shell, which uses $HOME/.sh_history; in future, pdksh may also use	a
	      default history file.

	      The number of commands normally stored for history, default 128.

       HOME   The  default directory for the cd command and the value substituted for an unquali-
	      fied ~ (see Tilde Expansion below).

       IFS    Internal field separator, used during substitution and  by  the  read  command,  to
	      split  values into distinct arguments; normally set to space, tab and newline.  See
	      Substitution above for details.
	      Note: this parameter is not  imported  from  the	environment  when  the	shell  is

	      The version of shell and the date the version was created (readonly).  See also the
	      version commands in Emacs Editing Mode and Vi Editing Mode sections, below.

       LINENO The line number of the function or shell script that is currently being executed.

       LINES  Set to the number of lines on the terminal or window.

	      Not implemented yet.

       MAIL   If set, the user will be informed of the arrival of mail in the named  file.   This
	      parameter is ignored if the MAILPATH parameter is set.

	      How  often,  in  seconds, the shell will check for mail in the file(s) specified by
	      MAIL or MAILPATH.  If 0, the shell checks before each prompt.  The default  is  600
	      (10 minutes).

	      A list of files to be checked for mail.  The list is colon separated, and each file
	      may be followed by a ? and a message to be printed if new mail has  arrived.   Com-
	      mand,  parameter and arithmetic substitution is performed on the message, and, dur-
	      ing substitution, the parameter $_ contains the name of the file.  The default mes-
	      sage is you have mail in $_.

       OLDPWD The  previous working directory.	Unset if cd has not successfully changed directo-
	      ries since the shell started, or if the shell doesn't know where it is.

       OPTARG When using getopts, it contains the argument for a parsed option,  if  it  requires

       OPTIND The  index  of the last argument processed when using getopts.  Assigning 1 to this
	      parameter causes getopts to process arguments from the beginning the next  time  it
	      is invoked.

       PATH   A  colon	separated list of directories that are searched when looking for commands
	      and .'d files.  An empty string resulting from a leading or trailing colon, or  two
	      adjacent colons is treated as a `.', the current directory.

	      If  set,	this  parameter  causes  the  posix option to be enabled.  See POSIX Mode

       PPID   The process ID of the shell's parent (readonly).

       PS1    PS1 is the primary prompt for interactive shells.  Parameter,  command  and  arith-
	      metic  substitutions are performed, and ! is replaced with the current command num-
	      ber (see fc command below).  A literal ! can be put in the prompt by placing !!  in
	      PS1.   Note  that  since	the  command  line editors try to figure out how long the
	      prompt is (so they know how far it is to edge of the screen), escape codes  in  the
	      prompt  tend  to	mess  things  up.   You  can  tell the shell not to count certain
	      sequences (such as escape codes) by prefixing your prompt with a non-printing char-
	      acter  (such  as	control-A)  followed by a carriage return and then delimiting the
	      escape codes with this non-printing character.  If you don't have any  non-printing
	      characters,  you're  out of luck...  BTW, don't blame me for this hack; it's in the
	      original ksh.  Default is `$ ' for non-root users, `# ' for root.

       PS2    Secondary prompt string, by default `> ', used when more input is  needed  to  com-
	      plete a command.

       PS3    Prompt used by select statement when reading a menu selection.  Default is `#? '.

       PS4    Used  to prefix commands that are printed during execution tracing (see set -x com-
	      mand below).  Parameter, command and arithmetic substitutions are performed  before
	      it is printed.  Default is `+ '.

       PWD    The  current working directory.  Maybe unset or null if shell doesn't know where it

       RANDOM A simple random number generator.  Every time RANDOM is referenced, it is  assigned
	      the  next  number in a random number series.  The point in the series can be set by
	      assigning a number to RANDOM (see rand(3)).

       REPLY  Default parameter for the read command if no names are given.  Also used in  select
	      loops to store the value that is read from standard input.

	      The  number  of  seconds	since  the  shell  started  or, if the parameter has been
	      assigned an integer value, the number of seconds	since  the  assignment	plus  the
	      value that was assigned.

       TMOUT  If set to a positive integer in an interactive shell, it specifies the maximum num-
	      ber of seconds the shell will wait for input  after  printing  the  primary  prompt
	      (PS1).  If the time is exceeded, the shell exits.

       TMPDIR The  directory shell temporary files are created in.  If this parameter is not set,
	      or does not contain the absolute path of a writable directory, temporary files  are
	      created in /tmp.

       VISUAL If  set,	this  parameter  controls  the	command line editing mode for interactive
	      shells.  If the last component of the path specified in this parameter contains the
	      string  vi,  emacs or gmacs, the vi, emacs or gmacs (Gosling emacs) editing mode is
	      enabled, respectively.

   Tilde Expansion
       Tilde expansion, which is done in parallel with parameter substitution, is done	on  words
       starting  with  an  unquoted ~.	The characters following the tilde, up to the first /, if
       any, are assumed to be a login name.  If the login name is empty, + or -, the value of the
       HOME, PWD, or OLDPWD parameter is substituted, respectively.  Otherwise, the password file
       is searched for the login name, and the tilde expression is substituted	with  the  user's
       home  directory.  If the login name is not found in the password file or if any quoting or
       parameter substitution occurs in the login name, no substitution is performed.

       In parameter assignments (those preceding a simple-command or those occurring in the argu-
       ments of alias, export, readonly, and typeset), tilde expansion is done after any unquoted
       colon (:), and login names are also delimited by colons.

       The home directory of previously expanded login names are cached and re-used.   The  alias
       -d  command  may  be  used  to  list,  change  and  add	to  this  cache  (e.g., `alias -d
       fac=/usr/local/facilities; cd ~fac/bin').

   Brace Expansion (alternation)
       Brace expressions, which take the form
       are expanded to N words, each of which is the concatenation of  prefix,	stri  and  suffix
       (e.g.,  `a{c,b{X,Y},d}e' expands to four word: ace, abXe, abYe, and ade).  As noted in the
       example, brace expressions can be nested and the resulting words are  not  sorted.   Brace
       expressions  must contain an unquoted comma (,) for expansion to occur (i.e., {} and {foo}
       are not expanded).  Brace expansion is carried out after parameter substitution and before
       file name generation.

   File Name Patterns
       A  file	name  pattern is a word containing one or more unquoted ? or * characters or [..]
       sequences.  Once brace expansion has been performed, the shell replaces file name patterns
       with the sorted names of all the files that match the pattern (if no files match, the word
       is left unchanged).  The pattern elements have the following meaning:

       ?      matches any single character.

       *      matches any sequence of characters.

       [..]   matches any of the characters inside the brackets.  Ranges  of  characters  can  be
	      specified by separating two characters by a -, e.g., [a0-9] matches the letter a or
	      any digit.  In order to represent itself, a - must either be quoted or the first or
	      last  character  in the character list.  Similarly, a ] must be quoted or the first
	      character in the list if it is represent itself instead of the  end  of  the  list.
	      Also,  a	!  appearing at the start of the list has special meaning (see below), so
	      to represent itself it must be quoted or appear later in the list.

       [!..]  like [..], except it matches any character not inside the brackets.

       *(pattern| ... |pattern)
	      matches any string of characters that matches zero or more occurrences of the spec-
	      ified  patterns.	 Example:  the	pattern *(foo|bar) matches the strings `', `foo',
	      `bar', `foobarfoo', etc..

       +(pattern| ... |pattern)
	      matches any string of characters that matches one or more occurrences of the speci-
	      fied  patterns.	Example: the pattern +(foo|bar) matches the strings `foo', `bar',
	      `foobarfoo', etc..

       ?(pattern| ... |pattern)
	      matches the empty string or a string that matches one of	the  specified	patterns.
	      Example: the pattern ?(foo|bar) only matches the strings `', `foo' and `bar'.

       @(pattern| ... |pattern)
	      matches  a string that matches one of the specified patterns.  Example: the pattern
	      @(foo|bar) only matches the strings `foo' and `bar'.

       !(pattern| ... |pattern)
	      matches any string that does not match one of the  specified  patterns.	Examples:
	      the pattern !(foo|bar) matches all strings except `foo' and `bar'; the pattern !(*)
	      matches no strings; the pattern !(?)* matches all strings (think about it).

       Note that pdksh currently never matches . and .., but the original ksh, Bourne sh and bash
       do, so this may have to change (too bad).

       Note  that none of the above pattern elements match either a period (.)	at the start of a
       file name or a slash (/), even if they are explicitly used in a [..] sequence;  also,  the
       names . and ..  are never matched, even by the pattern .*.

       If  the	markdirs option is set, any directories that result from file name generation are
       marked with a trailing /.

       The POSIX character classes (i.e., [:class-name:] inside a [..] expression)  are  not  yet

   Input/Output Redirection
       When  a	command is executed, its standard input, standard output and standard error (file
       descriptors 0, 1 and 2, respectively) are normally inherited from the shell.  Three excep-
       tions  to  this are commands in pipelines, for which standard input and/or standard output
       are those set up by the pipeline, asynchronous commands created when job control  is  dis-
       abled,  for  which  standard input is initially set to be from /dev/null, and commands for
       which any of the following redirections have been specified:

       > file standard output is redirected to file.  If file does not exist, it is  created;  if
	      it  does exist, is a regular file and the noclobber option is set, an error occurs,
	      otherwise the file is truncated.	Note that this means the command cmd < foo >  foo
	      will open foo for reading and then truncate it when it opens it for writing, before
	      cmd gets a chance to actually read foo.

       >| file
	      same as >, except the file is truncated, even if the noclobber option is set.

       >> file
	      same as >, except the file an existing file is appended to instead of  being  trun-
	      cated.   Also, the file is opened in append mode, so writes always go to the end of
	      the file (see open(2)).

       < file standard input is redirected from file, which is opened for reading.

       <> file
	      same as <, except the file is opened for reading and writing.

       << marker
	      after reading the command line containing this kind of redirection (called  a  here
	      document),  the  shell  copies  lines from the command source into a temporary file
	      until a line matching marker is read.  When the command is executed, standard input
	      is  redirected  from  the temporary file.  If marker contains no quoted characters,
	      the contents of the temporary file are processed as if enclosed  in  double  quotes
	      each  time  the command is executed, so parameter, command and arithmetic substitu-
	      tions are performed, along with backslash (\) escapes for $, `, \ and \newline.  If
	      multiple here documents are used on the same command line, they are saved in order.

       <<- marker
	      same as <<, except leading tabs are stripped from lines in the here document.

       <& fd  standard	input  is  duplicated from file descriptor fd.	fd can be a single digit,
	      indicating the number of an existing file descriptor, the letter p, indicating  the
	      file  descriptor associated with the output of the current co-process, or the char-
	      acter -, indicating standard input is to be closed.

       >& fd  same as <&, except the operation is done on standard output.

       In any of the above redirections, the file descriptor that is redirected  (i.e.,  standard
       input or standard output) can be explicitly given by preceding the redirection with a sin-
       gle digit.  Parameter, command and arithmetic substitutions, tilde substitutions  and  (if
       the  shell  is interactive) file name generation are all performed on the file, marker and
       fd arguments of redirections.  Note however, that the results of any file name  generation
       are  only  used	if  a  single file is matched; if multiple files match, the word with the
       unexpanded file name generation characters is used.  Note that in restricted shells, redi-
       rections which can create files cannot be used.

       For  simple-commands,  redirections  may appear anywhere in the command, for compound-com-
       mands (if statements, etc.), any redirections must appear at the  end.	Redirections  are
       processed after pipelines are created and in the order they are given, so
	      cat /foo/bar 2>&1 > /dev/null | cat -n
       will print an error with a line number prepended to it.

   Arithmetic Expressions
       Integer	arithmetic  expressions  can be used with the let command, inside $((..)) expres-
       sions, inside array references (e.g., name[expr]), as numeric arguments to the  test  com-
       mand, and as the value of an assignment to an integer parameter.

       Expression  may contain alpha-numeric parameter identifiers, array references, and integer
       constants and may be combined with the  following  C  operators	(listed  and  grouped  in
       increasing order of precedence).

       Unary operators:
	      + - ! ~ ++ --

       Binary operators:
	      = *= /= %= += -= <<= >>= &= ^= |=
	      == !=
	      < <= >= >
	      << >>
	      + -
	      * / %

       Ternary operator:
	      ?: (precedence is immediately higher than assignment)

       Grouping operators:
	      ( )

       Integer	constants  may	be specified with arbitrary bases using the notation base#number,
       where base is a decimal integer specifying the base, and number is a number in the  speci-
       fied base.

       The operators are evaluated as follows:

	      unary +
		     result is the argument (included for completeness).

	      unary -

	      !      logical not; the result is 1 if argument is zero, 0 if not.

	      ~      arithmetic (bit-wise) not.

	      ++     increment;  must  be  applied to a parameter (not a literal or other expres-
		     sion) - the parameter is incremented by 1.  When used as a prefix	operator,
		     the result is the incremented value of the parameter, when used as a postfix
		     operator, the result is the original value of the parameter.

	      --     similar to ++, except the parameter is decremented by 1.

	      ,      separates two arithmetic expressions; the left hand side is evaluated first,
		     then  the	right.	 The  result is value of the expression on the right hand

	      =      assignment; variable on the left is set to the value on the right.

	      *= /= %= += -= <<= >>= &= ^= |=
		     assignment operators; <var> <op>= <expr> is the same as <var> = <var> <op> (
		     <expr> ).

	      ||     logical  or;  the result is 1 if either argument is non-zero, 0 if not.  The
		     right argument is evaluated only if the left argument is zero.

	      &&     logical and; the result is 1 if both arguments are non-zero, 0 if not.   The
		     right argument is evaluated only if the left argument is non-zero.

	      |      arithmetic (bit-wise) or.

	      ^      arithmetic (bit-wise) exclusive-or.

	      &      arithmetic (bit-wise) and.

	      ==     equal; the result is 1 if both arguments are equal, 0 if not.

	      !=     not equal; the result is 0 if both arguments are equal, 1 if not.

	      <      less than; the result is 1 if the left argument is less than the right, 0 if

	      <= >= >
		     less than or equal, greater than or equal, greater than.  See <.

	      << >>  shift left (right); the result is the left argument with  its  bits  shifted
		     left (right) by the amount given in the right argument.

	      + - * /
		     addition, subtraction, multiplication, and division.

	      %      remainder;  the result is the remainder of the division of the left argument
		     by the right.  The sign of the result is unspecified if either  argument  is

	      <arg1> ? <arg2> : <arg3>
		     if <arg1> is non-zero, the result is <arg2>, otherwise <arg3>.

       A co-process, which is a pipeline created with the |& operator, is an asynchronous process
       that the shell can both write to (using print -p) and read  from  (using  read  -p).   The
       input and output of the co-process can also be manipulated using >&p and <&p redirections,
       respectively.  Once a co-process has been started, another can't be started until the  co-
       process	exits, or until the co-process input has been redirected using an exec n>&p redi-
       rection.  If a co-process's input is redirected in this way, the  next  co-process  to  be
       started	will share the output with the first co-process, unless the output of the initial
       co-process has been redirected using an exec n<&p redirection.

       Some notes concerning co-processes:
	 o    the only way to close the co-process input (so the co-process reads an end-of-file)
	      is  to  redirect	the  input to a numbered file descriptor and then close that file
	      descriptor (e.g., exec 3>&p;exec 3>&-).
	 o    in order for co-processes to share a common output, the shell must keep  the  write
	      portion  of the output pipe open.  This means that end of file will not be detected
	      until all co-processes sharing the co-process output have  exited  (when	they  all
	      exit,  the  shell closes its copy of the pipe).  This can be avoided by redirecting
	      the output to a numbered file descriptor (as this also causes the  shell	to  close
	      its  copy).   Note that this behaviour is slightly different from the original Korn
	      shell which closes its copy of the write portion of the co-processes'  output  when
	      the  most  recently  started  co-process (instead of when all sharing co-processes)
	 o    print -p will ignore SIGPIPE signals during writes  if  the  signal  is  not  being
	      trapped  or  ignored;  the same is not true if the co-process input has been dupli-
	      cated to another file descriptor and print -un is used.

       Functions are defined using either Korn shell function name  syntax  or	the  Bourne/POSIX
       shell  name()  syntax (see below for the difference between the two forms).  Functions are
       like .-scripts in that they are executed  in  the  current  environment,  however,  unlike
       .-scripts,  shell  arguments  (i.e.,  positional  parameters,  $1, etc.) are never visible
       inside them.  When the shell is determining the	location  of  a  command,  functions  are
       searched  after	special  built-in commands, and before regular and non-regular built-ins,
       and before the PATH is searched.

       An existing function may be deleted using unset -f function-name.  A list of functions can
       be  obtained using typeset +f and the function definitions can be listed using typeset -f.
       autoload (which is an alias for typeset -fu) may be used to  create  undefined  functions;
       when an undefined function is executed, the shell searches the path specified in the FPATH
       parameter for a file with the same name as the function, which, if found is read and  exe-
       cuted.	If after executing the file, the named function is found to be defined, the func-
       tion is executed, otherwise, the normal command	search	is  continued  (i.e.,  the  shell
       searches  the  regular  built-in  command  table and PATH).  Note that if a command is not
       found using PATH, an attempt is made to autoload a function using FPATH (this is an undoc-
       umented feature of the original Korn shell).

       Functions can have two attributes, trace and export, which can be set with typeset -ft and
       typeset -fx, respectively.  When a traced function is executed, the shell's xtrace  option
       is  turned  on for the functions duration, otherwise the xtrace option is turned off.  The
       export attribute of functions is currently not used.  In the original Korn shell, exported
       functions are visible to shell scripts that are executed.

       Since  functions are executed in the current shell environment, parameter assignments made
       inside functions are visible after the function completes.  If this  is	not  the  desired
       effect,	the  typeset  command  can be used inside a function to create a local parameter.
       Note that special parameters (e.g., $$, $!) can't be scoped in this way.

       The exit status of a function is that of the last command executed  in  the  function.	A
       function can be made to finish immediately using the return command; this may also be used
       to explicitly specify the exit status.

       Functions defined with the function reserved word are treated differently in the following
       ways from functions defined with the () notation:
	 o    the  $0  parameter is set to the name of the function (Bourne-style functions leave
	      $0 untouched).
	 o    parameter assignments preceding function calls are not kept in the  shell  environ-
	      ment (executing Bourne-style functions will keep assignments).
	 o    OPTIND  is  saved/reset and restored on entry and exit from the function so getopts
	      can be used properly both inside and outside the function  (Bourne-style	functions
	      leave  OPTIND  untouched,  so using getopts inside a function interferes with using
	      getopts outside the function).  In the future, the following differences will  also
	      be added:
	 o    A  separate trap/signal environment will be used during the execution of functions.
	      This will mean that traps set inside a function will not affect the  shell's  traps
	      and  signals that are not ignored in the shell (but may be trapped) will have their
	      default effect in a function.
	 o    The EXIT trap, if set in a function, will be executed after the function returns.

   POSIX Mode
       The shell is intended to be POSIX compliant, however, in some cases,  POSIX  behaviour  is
       contrary  either  to  the  original  Korn shell behaviour or to user convenience.  How the
       shell behaves in these cases is determined by the state of the posix option (set -o posix)
       -- if it is on, the POSIX behaviour is followed, otherwise it is not.  The posix option is
       set automatically when the shell starts up if the environment contains the POSIXLY_CORRECT
       parameter.   (The  shell can also be compiled so that it is in POSIX mode by default, how-
       ever this is usually not desirable).

       The following is a list of things that are affected by the state of the posix option:
	 o    kill -l output: in posix mode, signal names are listed one a single line;  in  non-
	      posix  mode,  signal  numbers,  names  and descriptions are printed in columns.  In
	      future, a new option (-v perhaps) will be added to distinguish the two behaviours.
	 o    fg exit status: in posix mode, the exit status is 0 if no  errors  occur;  in  non-
	      posix mode, the exit status is that of the last foregrounded job.
	 o    eval  exit status: if eval gets to see an empty command (e.g., eval "`false`"), its
	      exit status in posix mode will be 0.  In non-posix mode, it will be the exit status
	      of  the  last command substitution that was done in the processing of the arguments
	      to eval (or 0 if there were no command substitutions).
	 o    getopts: in posix mode, options must start with a -; in non-posix mode, options can
	      start with either - or +.
	 o    brace expansion (also known as alternation): in posix mode, brace expansion is dis-
	      abled; in non-posix mode, brace expansion enabled.  Note that set -o posix (or set-
	      ting the POSIXLY_CORRECT parameter) automatically turns the braceexpand option off,
	      however it can be explicitly turned on later.
	 o    set -: in posix mode, this does not clear the verbose or xtrace  options;  in  non-
	      posix mode, it does.
	 o    set exit status: in posix mode, the exit status of set is 0 if there are no errors;
	      in non-posix mode, the exit status is that of any command  substitutions	performed
	      in  generating the set command.  For example, `set -- `false`; echo $?' prints 0 in
	      posix mode, 1 in non-posix mode.	This construct is used in most shell scripts that
	      use the old getopt(1) command.
	 o    argument expansion of alias, export, readonly, and typeset commands: in posix mode,
	      normal argument expansion done; in non-posix mode, field splitting,  file  globing,
	      brace  expansion	and (normal) tilde expansion are turned off, and assignment tilde
	      expansion is turned on.
	 o    signal specification: in posix mode, signals can be specified  as  digits  only  if
	      signal  numbers  match  POSIX  values  (i.e., HUP=1, INT=2, QUIT=3, ABRT=6, KILL=9,
	      ALRM=14, and TERM=15); in non-posix mode, signals can be always digits.
	 o    alias expansion: in posix mode, alias expansion is only carried  out  when  reading
	      command  words;  in non-posix mode, alias expansion is carried out on any word fol-
	      lowing an alias that ended in a space.  For example, the following for loop
	      alias a='for ' i='j'
	      a i in 1 2; do echo i=$i j=$j; done
       uses parameter i in posix mode, j in non-posix mode.
	 o    test: in posix mode, the expression "-t" (preceded by some number of "!" arguments)
	      is  always  true	as it is a non-zero length string; in non-posix mode, it tests if
	      file descriptor 1 is a tty (i.e., the fd argument to the -t test may  be	left  out
	      and defaults to 1).

   Command Execution
       After  evaluation  of  command line arguments, redirections and parameter assignments, the
       type of command is determined: a special built-in, a function, a regular built-in  or  the
       name  of  a  file  to  execute found using the PATH parameter.  The checks are made in the
       above order.  Special built-in commands differ from other commands in that the PATH param-
       eter is not used to find them, an error during their execution can cause a non-interactive
       shell to exit and parameter assignments that are specified before  the  command	are  kept
       after  the  command  completes.	Just to confuse things, if the posix option is turned off
       (see set command below) some special commands are very special in that no field splitting,
       file globing, brace expansion nor tilde expansion is performed on arguments that look like
       assignments.  Regular built-in commands are different only in that the PATH  parameter  is
       not used to find them.

       The  original  ksh  and	POSIX differ somewhat in which commands are considered special or

       POSIX special commands

	      . 	 continue   exit       return	  trap
	      : 	 eval	    export     set	  unset
	      break	 exec	    readonly   shift

       Additional ksh special commands

	      builtin	 times	    typeset

       Very special commands (non-posix mode)

	      alias	 readonly   set        typeset

       POSIX regular commands

	      alias	 command    fg	       kill	  umask
	      bg	 false	    getopts    read	  unalias
	      cd	 fc	    jobs       true	  wait

       Additional ksh regular commands

	      [ 	 let	    pwd        ulimit
	      echo	 print	    test       whence

       In the future, the additional ksh special and regular commands may be treated  differently
       from the POSIX special and regular commands.

       Once  the  type of the command has been determined, any command line parameter assignments
       are performed and exported for the duration of the command.

       The following describes the special and regular built-in commands:

       . file [arg1 ...]
	      Execute the commands in file in the current environment.	The file is searched  for
	      in  the directories of PATH.  If arguments are given, the positional parameters may
	      be used to access them while file is being executed.  If no  arguments  are  given,
	      the positional parameters are those of the environment the command is used in.

       : [ ... ]
	      The null command.  Exit status is set to zero.

       alias [ -d | +-t [-r] ] [+-px] [+-] [name1[=value1] ...]
	      Without  arguments,  alias  lists  all  aliases.	For any name without a value, the
	      existing alias is listed.  Any name with a value	defines  an  alias  (see  Aliases

	      When  listing  aliases, one of two formats is used: normally, aliases are listed as
	      name=value, where value is quoted; if options were preceded with + or a lone  +  is
	      given  on the command line, only name is printed.  In addition, if the -p option is
	      used, each alias is prefixed with the string "alias ".

	      The -x option sets (+x clears) the export attribute of an alias, or,  if	no  names
	      are  given,  lists the aliases with the export attribute (exporting an alias has no

	      The -t option indicates that tracked aliases are to be listed/set (values specified
	      on the command line are ignored for tracked aliases).  The -r option indicates that
	      all tracked aliases are to be reset.

	      The -d causes directory aliases, which are used in tilde expansion, to be listed or
	      set (see Tilde Expansion above).

       bg [job ...]
	      Resume  the  specified stopped job(s) in the background.	If no jobs are specified,
	      %+ is assumed.  This command is only available on systems which  support	job  con-
	      trol.  See Job Control below for more information.

       bind [-l] [-m] [key[=editing-command] ...]
	      Set or view the current emacs command editing key bindings/macros.  See Emacs Edit-
	      ing Mode below for a complete description.

       break [level]
	      break exits the levelth inner most  for,	select,  until,  or  while  loop.   level
	      defaults to 1.

       builtin command [arg1 ...]
	      Execute the built-in command command.

       cd [-LP] [dir]
	      Set  the working directory to dir.  If the parameter CDPATH is set, it lists direc-
	      tories to search in for dir.  An empty entry in the CDPATH entry means the  current
	      directory.   If  a non-empty directory from CDPATH is used, the resulting full path
	      is printed to standard output.  If dir is missing,  the  home  directory	$HOME  is
	      used.   If dir is -, the previous working directory is used (see OLDPWD parameter).
	      If -L option (logical path) is used or if the  physical  option  (see  set  command
	      below)  isn't set, references to .. in dir are relative to the path used get to the
	      directory.  If -P option (physical path) is used or if the physical option is  set,
	      .. is relative to the filesystem directory tree.	The PWD and OLDPWD parameters are
	      updated to reflect the current and old wording directory, respectively.

       cd [-LP] old new
	      The string new is substituted for old in	the  current  directory,  and  the  shell
	      attempts to change to the new directory.

       command [-pvV] cmd [arg1 ...]
	      If  neither the -v nor -V options are given, cmd is executed exactly as if the com-
	      mand had not been specified, with two exceptions: first,	cmd  cannot  be  a  shell
	      function, and second, special built-in commands lose their specialness (i.e., redi-
	      rection and utility errors do not cause the shell to exit, and command  assignments
	      are  not	permanent).   If  the  -p  option is given, a default search path is used
	      instead of the current value of PATH (the actual value of the default path is  sys-
	      tem dependent: on POSIXish systems, it is the value returned by
						getconf CS_PATH

	      If  the  -v option is given, instead of executing cmd, information about what would
	      be executed is given (and the same is done for arg1 ...): for special  and  regular
	      built-in	commands  and  functions,  their names are simply printed, for aliases, a
	      command that defines them is printed, and for commands found by searching the  PATH
	      parameter, the full path of the command is printed.  If no command is found, (i.e.,
	      the path search fails), nothing is printed and command exits with a  non-zero  sta-
	      tus.  The -V option is like the -v option, except it is more verbose.

       continue [levels]
	      continue	jumps  to  the beginning of the levelth inner most for, select, until, or
	      while loop.  level defaults to 1.

       echo [-neE] [arg ...]
	      Prints its arguments (separated by spaces) followed by a newline, to standard  out.
	      The  newline  is	suppressed if any of the arguments contain the backslash sequence
	      \c.  See print command below for a list of other backslash sequences that are  rec-

	      The  options  are  provided for compatibility with BSD shell scripts: -n suppresses
	      the trailing newline, -e enables backslash interpretation (a no-op, since  this  is
	      normally done), and -E suppresses backslash interpretation.

       eval command ...
	      The  arguments  are concatenated (with spaces between them) to form a single string
	      which the shell then parses and executes in the current environment.

       exec [command [arg ...]]
	      The command is executed without forking, replacing the shell process.

	      If no arguments are given, any IO redirection is permanent and  the  shell  is  not
	      replaced.   Any  file  descriptors  greater than 2 which are opened or dup(2)-ed in
	      this way are not made available to other executed commands (i.e., commands that are
	      not  built-in to the shell).  Note that the Bourne shell differs here: it does pass
	      these file descriptors on.

       exit [status]
	      The shell exits with the specified exit status.  If status is  not  specified,  the
	      exit status is the current value of the ? parameter.

       export [-p] [parameter[=value]] ...
	      Sets  the export attribute of the named parameters.  Exported parameters are passed
	      in the environment to executed commands.	If values are specified, the named param-
	      eters also assigned.

	      If  no  parameters  are  specified,  the	names  of  all parameters with the export
	      attribute are printed one per line, unless the -p option is  used,  in  which  case
	      export  commands	defining  all  exported  parameters,  including their values, are

       false  A command that exits with a non-zero status.

       fc [-e editor | -l [-n]] [-r] [first [last]]
	      first and last select commands from the history.	Commands can be selected by  his-
	      tory  number,  or  a  string  specifying the most recent command starting with that
	      string.  The -l option lists the command on stdout, and  -n  inhibits  the  default
	      command  numbers.   The  -r option reverses the order of the list.  Without -l, the
	      selected commands are edited by the editor specified with the -e option, or  if  no
	      -e is specified, the editor specified by the FCEDIT parameter (if this parameter is
	      not set, /bin/ed is used), and then executed by the shell.

       fc [-e - | -s] [-g] [old=new] [prefix]
	      Re-execute the selected command (the previous command by default) after  performing
	      the  optional substitution of old with new.  If -g is specified, all occurrences of
	      old are replaced with new.  This command is usually accessed  with  the  predefined
	      alias r='fc -e -'.

       fg [job ...]
	      Resume  the  specified  job(s)  in the foreground.  If no jobs are specified, %+ is
	      assumed.	This command is only available on systems which support job control.  See
	      Job Control below for more information.

       getopts optstring name [arg ...]
	      getopts is used by shell procedures to parse the specified arguments (or positional
	      parameters, if no arguments are given) and to check for legal  options.	optstring
	      contains	the option letters that getopts is to recognize.  If a letter is followed
	      by a colon, the option is expected to have an argument.  Options that do	not  take
	      arguments  may be grouped in a single argument.  If an option takes an argument and
	      the option character is not the last character of the argument it is found in,  the
	      remainder of the argument is taken to be the option's argument, otherwise, the next
	      argument is the option's argument.

	      Each time getopts is invoked, it places the next option in the shell parameter name
	      and  the	index of the next argument to be processed in the shell parameter OPTIND.
	      If the option was introduced with a +, the option placed in name is prefixed with a
	      +.   When  an option requires an argument, getopts places it in the shell parameter
	      OPTARG.  When an illegal option or a missing option argument is encountered a ques-
	      tion  mark  or  a  colon is placed in name (indicating an illegal option or missing
	      argument, respectively) and OPTARG is set to the option character that  caused  the
	      problem.	 An error message is also printed to standard error if optstring does not
	      begin with a colon.

	      When the end of the options is encountered, getopts exits with a non-zero exit sta-
	      tus.   Options end at the first (non-option) argument that does not start with a -,
	      or when a -- argument is encountered.

	      Option parsing can be reset by setting OPTIND to	1  (this  is  done  automatically
	      whenever the shell or a shell procedure is invoked).

	      Warning:	Changing the value of the shell parameter OPTIND to a value other than 1,
	      or parsing different sets of arguments without resetting OPTIND may lead	to  unex-
	      pected results.

       hash [-r] [name ...]
	      Without  arguments,  any	hashed	executable  command pathnames are listed.  The -r
	      option causes all hashed commands to be removed from the hash table.  Each name  is
	      searched as if it where a command name and added to the hash table if it is an exe-
	      cutable command.

       jobs [-lpn] [job ...]
	      Display information about the specified jobs; if no jobs are  specified,	all  jobs
	      are displayed.  The -n option causes information to be displayed only for jobs that
	      have changed state since the last notification.  If the  -l  option  is  used,  the
	      process-id  of each process in a job is also listed.  The -p option causes only the
	      process group of each job to be printed.	See Job Control below for the  format  of
	      job and the displayed job.

       kill [-s signame | -signum | -signame ] { job | pid | -pgrp } ...
	      Send  the  specified  signal to the specified jobs, process ids, or process groups.
	      If no signal is specified, the signal TERM is sent.  If a  job  is  specified,  the
	      signal is sent to the job's process group.  See Job Control below for the format of

       kill -l [exit-status ...]
	      Print the name of the signal that killed a process which exited with the	specified
	      exit-statuses.   If  no  arguments  are specified, a list of all the signals, their
	      numbers and a short description of them are printed.

       let [expression ...]
	      Each expression is evaluated, see Arithmetic Expressions above.  If all expressions
	      are  successfully evaluated, the exit status is 0 (1) if the last expression evalu-
	      ated to non-zero (zero).	If an error occurs during the parsing or evaluation of an
	      expression,  the	exit  status is greater than 1.  Since expressions may need to be
	      quoted, (( expr )) is syntactic sugar for let "expr".

       print [-nprsun | -R [-en]] [argument ...]
	      Print prints its arguments on the standard output, separated by spaces, and  termi-
	      nated with a newline.  The -n option suppresses the newline.  By default, certain C
	      escapes are translated.  These include \b, \f, \n, \r, \t, \v, and \0### (#  is  an
	      octal  digit,  of  which	there  may  be 0 to 3).  \c is equivalent to using the -n
	      option.  \ expansion may be inhibited with the -r option.  The -s option prints  to
	      the  history file instead of standard output, the -u option prints to file descrip-
	      tor n (n defaults to 1 if omitted), and the -p option prints to the co-process (see
	      Co-Processes above).

	      The  -R option is used to emulate, to some degree, the BSD echo command, which does
	      not process \ sequences unless the -e option is given.  As  above,  the  -n  option
	      suppresses the trailing newline.

       pwd [-LP]
	      Print  the  present  working  directory.	 If  -L option is used or if the physical
	      option (see set command below) isn't set, the logical path is  printed  (i.e.,  the
	      path used to cd to the current directory).  If -P option (physical path) is used or
	      if the physical option is set, the path determined from the filesystem (by  follow-
	      ing ..  directories to the root directory) is printed.

       read [-prsun] [parameter ...]
	      Reads  a line of input from standard input, separate the line into fields using the
	      IFS parameter (see Substitution above), and assign  each	field  to  the	specified
	      parameters.  If there are more parameters than fields, the extra parameters are set
	      to null, or alternatively, if there are  more  fields  than  parameters,	the  last
	      parameter  is  assigned  the remaining fields (inclusive of any separating spaces).
	      If no parameters are specified, the REPLY parameter is used.   If  the  input  line
	      ends  in	a backslash and the -r option was not used, the backslash and newline are
	      stripped and more input is read.	If no input is read, read exits with  a  non-zero

	      The  first parameter may have a question mark and a string appended to it, in which
	      case the string is used as a prompt (printed to standard error before any input  is
	      read) if the input is a tty (e.g., read nfoo?'number of foos: ').

	      The -un and -p options cause input to be read from file descriptor n or the current
	      co-process (see Co-Processes above for comments on this), respectively.  If the  -s
	      option is used, input is saved to the history file.

       readonly [-p] [parameter[=value]] ...
	      Sets  the readonly attribute of the named parameters.  If values are given, parame-
	      ters are set to them before setting the attribute.  Once a parameter is made  read-
	      only, it cannot be unset and its value cannot be changed.

	      If  no  parameters  are  specified,  the	names of all parameters with the readonly
	      attribute are printed one per line, unless the -p option is  used,  in  which  case
	      readonly	commands  defining  all  readonly parameters, including their values, are

       return [status]
	      Returns from a function or . script, with exit status  status.   If  no  status  is
	      given,  the exit status of the last executed command is used.  If used outside of a
	      function or . script, it has the same effect as exit.  Note that pdksh treats  both
	      profile and $ENV files as . scripts, while the original Korn shell only treats pro-
	      files as . scripts.

       set [+-abCefhkmnpsuvxX] [+-o [option]] [+-A name] [--] [arg ...]
	      The set command can be used to set (-) or clear (+) shell options,  set  the  posi-
	      tional parameters, or set an array parameter.  Options can be changed using the +-o
	      option syntax, where option is the long name of an option, or  using  the  +-letter
	      syntax,  where  letter  is  the option's single letter name (not all options have a
	      single letter name).  The following table lists both option letters (if they exist)
	      and long names along with a description of what the option does.

	       -A						   Sets the elements of the array
								   parameter name to arg ...;  If
								   -A is used, the array is reset
								   (i.e., emptied) first;  if  +A
								   is  used, the first N elements
								   are set (where N is the number
								   of  args),  the  rest are left
	       -a		   allexport			   all new parameters are created
								   with the export attribute
	       -b		   notify			   Print  job  notification  mes-
								   sages asynchronously,  instead
								   of  just  before  the  prompt.
								   Only used if  job  control  is
								   enabled (-m).
	       -C		   noclobber			   Prevent   >	redirection  from
								   overwriting existing files (>|
								   must be used to force an over-

	       -e		   errexit			   Exit (after executing the  ERR
								   trap)  as  soon  as	an  error
								   occurs  or  a  command   fails
								   (i.e.,  exits  with a non-zero
								   status).  This does not  apply
								   to  commands whose exit status
								   is  explicitly  tested  by	a
								   shell  construct  such  as if,
								   until, while, && or ||  state-
	       -f		   noglob			   Do  not  expand file name pat-
	       -h		   trackall			   Create tracked aliases for all
								   executed commands (see Aliases
								   above).   On  by  default  for
								   non-interactive shells.
	       -i		   interactive			   Enable interactive mode - this
								   can only be set/unset when the
								   shell is invoked.
	       -k		   keyword			   Parameter assignments are rec-
								   ognized anywhere in a command.
	       -l		   login			   The shell is a login  shell	-
								   this  can  only  be	set/unset
								   when the shell is invoked (see
								   Shell Startup above).
	       -m		   monitor			   Enable  job	control  (default
								   for interactive shells).
	       -n		   noexec			   Do not execute any commands	-
								   useful for checking the syntax
								   of scripts (ignored if  inter-
	       -p		   privileged			   Set automatically if, when the
								   shell starts, the real uid  or
								   gid	does not match the effec-
								   tive uid or gid, respectively.
								   See	Shell Startup above for a
								   description	 of   what   this
	       -r		   restricted			   Enable restricted mode -- this
								   option can only be  used  when
								   the	shell  is  invoked.   See
								   Shell  Startup  above  for	a
								   description	 of   what   this
	       -s		   stdin			   If  used  when  the	shell  is
								   invoked,   commands	are  read
								   from  standard   input.    Set
								   automatically  if the shell is
								   invoked with no arguments.

								   When -s is  used  in  the  set
								   command,  it causes the speci-
								   fied arguments  to  be  sorted
								   before  assigning  them to the
								   positional parameters  (or  to
								   array name, if -A is used).
	       -u		   nounset			   Referencing of an unset param-
								   eter is treated as  an  error,
								   unless  one	of  the -, + or =
								   modifiers is used.
	       -v		   verbose			   Write shell input to  standard
								   error as it is read.
	       -x		   xtrace			   Print  commands  and parameter
								   assignments when they are exe-
								   cuted,  preceded  by the value
								   of PS4.
	       -X		   markdirs			   Mark directories with a trail-
								   ing / during file name genera-
				   bgnice			   Background jobs are	run  with
								   lower priority.
				   braceexpand			   Enable  brace  expansion (aka,

				   emacs			   Enable BRL emacs-like  command
								   line    editing   (interactive
								   shells only); see Emacs  Edit-
								   ing Mode.
				   emacs-usemeta		   In emacs command-line editing,
								   use the 8th bit as  meta  (^[)
								   prefix.   This  is the default
								   if LC_CTYPE is unset or  POSIX
								   respectively C.  8
				   gmacs			   Enable   gmacs-like	 (Gosling
								   emacs)  command  line  editing
								   (interactive   shells   only);
								   currently identical	to  emacs
								   editing  except that transpose
								   (^T)  acts  slightly   differ-
				   ignoreeof			   The	shell  will  not (easily)
								   exit on  when  end-of-file  is
								   read,  exit	must be used.  To
								   avoid  infinite   loops,   the
								   shell will exit if eof is read
								   13 times in a row.
				   nohup			   Do not kill running jobs  with
								   a  HUP  signal  when  a  login
								   shell exists.   Currently  set
								   by	default,  but  this  will
								   change in  the  future  to  be
								   compatible  with  the original
								   Korn shell (which doesn't have
								   this option, but does send the
								   HUP signal).
				   nolog			   No effect -	in  the  original
								   Korn   shell,   this  prevents
								   function   definitions    from
								   being  stored  in  the history
				   physical			   Causes the cd and pwd commands
								   to  use  `physical' (i.e., the
								   filesystem's)  ..  directories
								   instead  of `logical' directo-
								   ries (i.e.,	the shell handles
								   ..,	which  allows the user to
								   be oblivious of symlink  links
								   to	directories).	Clear  by
								   default.   Note  that  setting
								   this  option  does  not effect
								   the current value of  the  PWD
								   parameter; only the cd command
								   changes PWD.  See the  cd  and
								   pwd	commands  above  for more
				   posix			   Enable posix mode.  See  POSIX
								   Mode above.
				   vi				   Enable  vi-like  command  line
								   editing  (interactive   shells
				   viraw			   No  effect  -  in the original
								   Korn shell, unless  viraw  was
								   set,  the vi command line mode
								   would let the  tty  driver  do
								   the	work  until  ESC (^[) was
								   entered.  pdksh is  always  in
								   viraw mode.
				   vi-esccomplete		   In vi command line editing, do
								   command / file name completion
								   when escape (^[) is entered in
								   command mode.
				   vi-show8			   Prefix  characters  with   the
								   eighth  bit set with `M-'.  If
								   this option is not set,  char-
								   acters  in  the  range 128-160
								   are printed as is,  which  may
								   cause problems.

				   vi-tabcomplete		   In vi command line editing, do
								   command / file name completion
								   when  tab  (^I)  is entered in
								   insert  mode.   This  is   the

	      These  options  can  also be used upon invocation of the shell.  The current set of
	      options (with single letter names) can be found in the parameter -.  set -o with no
	      option  name  will  list all the options and whether each is on or off; set +o will
	      print the long names of all options that are currently on.

	      Remaining arguments, if any, are positional parameters and are assigned, in  order,
	      to  the positional parameters (i.e., 1, 2, etc.).  If options are ended with -- and
	      there are no remaining arguments, all positional parameters  are	cleared.   If  no
	      options  or  arguments  are  given,  then the values of all names are printed.  For
	      unknown historical reasons, a lone - option is treated specially:  it  clears  both
	      the -x and -v options.

       shift [number]
	      The positional parameters number+1, number+2 etc. are renamed to 1, 2, etc.  number
	      defaults to 1.

       test expression

       [ expression ]
	      test evaluates the expression and returns zero status if	true,  1  if  false,  and
	      greater than 1 if there was an error.  It is normally used as the condition command
	      of if and while statements.  The following basic expressions are available:

	       str		    str has non-zero  length.	Note
				    that  there is the potential for
				    problems if str turns out to  be
				    an	operator  (e.g., -r) - it is
				    generally better to use  a	test
					    [ X"str" != X ]
				    instead  (double quotes are used
				    in case str contains  spaces  or
				    file globing characters).
	       -r file		    file exists and is readable.
	       -w file		    file exists and is writable.
	       -x file		    file exists and is executable.
	       -a file		    file exists.
	       -e file		    file exists.
	       -f file		    file is a regular file.
	       -d file		    file is a directory.
	       -c file		    file   is  a  character  special
	       -b file		    file is a block special device.
	       -p file		    file is a named pipe.
	       -u file		    file's mode has setuid bit set.
	       -g file		    file's mode has setgid bit set.
	       -k file		    file's mode has sticky bit set.
	       -s file		    file is not empty.
	       -O file		    file's  owner  is  the   shell's
				    effective user-ID.
	       -G file		    file's   group  is	the  shell's
				    effective group-ID.
	       -h file		    file is a symbolic link.
	       -H file		    file  is  a  context   dependent
				    directory  (only  useful  on HP-
	       -L file		    file is a symbolic link.
	       -S file		    file is a socket.
	       -o option	    shell option  is  set  (see  set
				    command   above   for   list  of
				    options).	As  a	non-standard
				    extension,	if the option starts
				    with a !, the test	is  negated;
				    the  test always fails if option
				    doesn't exist (thus
					 [ -o foo -o -o !foo ]
				    returns  true  if  and  only  if
				    option foo exists).

	       file -nt file	    first  file is newer than second
				    file or first  file  exists  and
				    the second file does not.
	       file -ot file	    first  file is older than second
				    file or second file  exists  and
				    the first file does not.
	       file -ef file	    first  file  is the same file as
				    second file.
	       -t [fd]		    file descriptor is a tty device.
				    If	the  posix  option  (set  -o
				    posix, see POSIX Mode above)  is
				    not  set, fd may be left out, in
				    which case it is taken to  be  1
				    (the  behaviour  differs  due to
				    the    special    POSIX    rules
				    described below).
	       string		    string is not empty.
	       -z string	    string is empty.
	       -n string	    string is not empty.
	       string = string	    strings are equal.
	       string == string     strings are equal.
	       string != string     strings are not equal.
	       number -eq number    numbers compare equal.
	       number -ne number    numbers compare not equal.
	       number -ge number    numbers  compare greater than or
	       number -gt number    numbers compare greater than.
	       number -le number    numbers  compare  less  than  or
	       number -lt number    numbers compare less than.

	      The  above  basic expressions, in which unary operators have precedence over binary
	      operators, may be combined with the following operators (listed in increasing order
	      of precedence):

	       expr -o expr    logical or
	       expr -a expr    logical and
	       ! expr	       logical not
	       ( expr )        grouping

	      On operating systems not supporting /dev/fd/n devices (where n is a file descriptor
	      number), the test command will attempt to fake it for all  tests	that  operate  on
	      files  (except  the -e test).  I.e., [ -w /dev/fd/2 ] tests if file descriptor 2 is

	      Note that some special rules are applied (courtesy of POSIX) if the number of argu-
	      ments  to test or [ ... ] is less than five: if leading ! arguments can be stripped
	      such that only one argument remains then a string length test is performed  (again,
	      even  if	the argument is a unary operator); if leading ! arguments can be stripped
	      such that three arguments remain and the second argument is a binary operator, then
	      the  binary  operation  is  performed  (even if first argument is a unary operator,
	      including an unstripped !).

	      Note: A common mistake is to use if [ $foo = bar ] which fails if parameter foo  is
	      null  or	unset,	if  it	has embedded spaces (i.e., IFS characters), or if it is a
	      unary operator like ! or -n.  Use tests like if [ "X$foo" = Xbar ] instead.

       time [-p] [ pipeline ]
	      If a pipeline is given, the times used to execute the pipeline are reported.  If no
	      pipeline	is given, then the user and system time used by the shell itself, and all
	      the commands it has run since it was started, are reported.  The times reported are
	      the  real  time  (elapsed time from start to finish), the user CPU time (time spent
	      running in user mode) and the system CPU time (time spent running in kernel  mode).
	      Times are reported to standard error; the format of the output is:
		  0.00s real	 0.00s user	0.00s system
	      unless  the  -p option is given (only possible if pipeline is a simple command), in
	      which case the output is slightly longer:
		  real	 0.00
		  user	 0.00
		  sys	 0.00
	      (the number of digits after the decimal may vary from system to system).	Note that
	      simple redirections of standard error do not effect the output of the time command:
					     time sleep 1 2> afile
					  { time sleep 1; } 2> afile
	      times for the first command do not go to afile, but those of the second command do.

       times  Print  the  accumulated  user  and  system times used by the shell and by processes
	      which have exited that the shell started.

       trap [handler signal ...]
	      Sets trap handler that is to be executed when any  of  the  specified  signals  are
	      received.   Handler  is  either  a  null	string,  indicating the signals are to be
	      ignored, a minus (-), indicating that the default action is to  be  taken  for  the
	      signals  (see signal(3)), or a string containing shell commands to be evaluated and
	      executed at the first opportunity (i.e., when the  current  command  completes,  or
	      before  printing	the next PS1 prompt) after receipt of one of the signals.  Signal
	      is the name of a signal (e.g., PIPE or ALRM) or the number of the signal (see  kill
	      -l command above).  There are two special signals: EXIT (also known as 0), which is
	      executed when the shell is about to exit, and ERR which is executed after an  error
	      occurs  (an  error  is  something  that  would cause the shell to exit if the -e or
	      errexit option were set -- see set command above).  EXIT handlers are  executed  in
	      the  environment	of  the  last  executed  command.   Note that for non-interactive
	      shells, the trap handler cannot be changed for signals that were ignored	when  the
	      shell started.

	      With  no	arguments, trap lists, as a series of trap commands, the current state of
	      the traps that have been set since the shell started.  Note that the output of trap
	      can  not	be  usefully piped to another process (an artifact of the fact that traps
	      are cleared when subprocesses are created).

	      The original Korn shell's DEBUG trap and the handling of	ERR  and  EXIT	traps  in
	      functions are not yet implemented.

       true   A command that exits with a zero value.

       typeset [[+-Ulprtux] [-L[n]] [-R[n]] [-Z[n]] [-i[n]] | -f [-tux]] [name[=value] ...]
	      Display  or set parameter attributes.  With no name arguments, parameter attributes
	      are displayed: if no options arg used, the current attributes of all parameters are
	      printed as typeset commands; if an option is given (or - with no option letter) all
	      parameters and their values with the specified attributes are printed;  if  options
	      are introduced with +, parameter values are not printed.

	      If  name arguments are given, the attributes of the named parameters are set (-) or
	      cleared (+).  Values for parameters may optionally be  specified.   If  typeset  is
	      used inside a function, any newly created parameters are local to the function.

	      When  -f is used, typeset operates on the attributes of functions.  As with parame-
	      ters, if no names are given, functions are listed with their values (i.e.,  defini-
	      tions)  unless options are introduced with +, in which case only the function names
	      are reported.

	       -Ln				    Left justify attribute: n specifies the field
						    width.   If  n  is not specified, the current
						    width of a parameter (or  the  width  of  its
						    first assigned value) is used.  Leading white
						    space (and zeros, if used with the -Z option)
						    is stripped.  If necessary, values are either
						    truncated or space padded to  fit  the  field
	       -Rn				    Right  justify  attribute:	n  specifies  the
						    field width.  If n is not specified, the cur-
						    rent  width  of  a parameter (or the width of
						    its first assigned value) is used.	 Trailing
						    white space are stripped.  If necessary, val-
						    ues are either stripped of leading characters
						    or	space  padded  to make them fit the field
	       -Zn				    Zero fill attribute: if not combined with -L,
						    this  is  the same as -R, except zero padding
						    is used instead of space padding.
	       -in				    integer attribute: n specifies  the  base  to
						    use when displaying the integer (if not spec-
						    ified, the base given in the first assignment
						    is used).  Parameters with this attribute may
						    be	assigned  values  containing   arithmetic
	       -U				    unsigned   integer	attribute:  integers  are
						    printed as unsigned values (only useful  when
						    combined with the -i option).  This option is
						    not in the original Korn shell.

	       -f				    Function mode: display or set  functions  and
						    their attributes, instead of parameters.
	       -l				    Lower case attribute: all  upper case charac-
						    ters in values are converted to  lower  case.
						    (In  the  original Korn shell, this parameter
						    meant `long integer' when used  with  the  -i
	       -p				    Print  complete  typeset commands that can be
						    used to re-create the attributes (but not the
						    values)  of  parameters.  This is the default
						    action (option exists for  ksh93  compatibil-
	       -r				    Readonly  attribute: parameters with the this
						    attribute may not be assigned  to  or  unset.
						    Once  this	attribute  is  set, it can not be
						    turned off.
	       -t				    Tag attribute: has no meaning to  the  shell;
						    provided for application use.

						    For  functions,  -t  is  the trace attribute.
						    When functions with the trace  attribute  are
						    executed,  the  xtrace  (-x)  shell option is
						    temporarily turned on.
	       -u				    Upper case attribute: all lower case  charac-
						    ters  in  values are converted to upper case.
						    (In the original Korn shell,  this	parameter
						    meant  `unsigned  integer' when used with the
						    -i option, which  meant  upper  case  letters
						    would  never  be  used for bases greater than
						    10.  See the -U option).

						    For functions, -u is the undefined attribute.
						    See  Functions  above for the implications of
	       -x				    Export attribute: parameters  (or  functions)
						    are placed in the environment of any executed
						    commands.  Exported functions are not  imple-
						    mented yet.

       ulimit [-abcdfHlmnpsStvw] [value]
	      Display or set process limits.  If no options are used, the file size limit (-f) is
	      assumed.	value, if specified, may be either be an  arithmetic  expression  or  the
	      word unlimited.  The limits affect the shell and any processes created by the shell
	      after a limit is imposed.  Note that some  systems  may  not  allow  limits  to  be
	      increased once they are set.  Also note that the types of limits available are sys-
	      tem dependent - some systems have only the -f limit.

	      -a     Displays all limits; unless -H is used, soft limits are displayed.

	      -H     Set the hard limit only (default is to set both hard and soft limits).

	      -S     Set the soft limit only (default is to set both hard and soft limits).

	      -b     Impose a size limit of n bytes on the size of socket buffers.

	      -c     Impose a size limit of n blocks on the size of core dumps.

	      -d     Impose a size limit of n kbytes on the size of the data area.

	      -f     Impose a size limit of n blocks on files written by the shell and its  child
		     processes (files of any size may be read).

	      -l     Impose a limit of n kbytes on the amount of locked (wired) physical memory.

	      -m     Impose a limit of n kbytes on the amount of physical memory used.

	      -n     Impose a limit of n file descriptors that can be open at once.

	      -p     Impose a limit of n processes that can be run by the user at any one time.

	      -s     Impose a size limit of n kbytes on the size of the stack area.

	      -t     Impose a time limit of n CPU seconds to be used by each process.

	      -v     Impose  a	limit  of  n kbytes on the amount of virtual memory used; on some
		     systems this is  the  maximum  allowable  virtual	address  (in  bytes,  not

	      -w     Impose a limit of n kbytes on the amount of swap space used.

	      As far as ulimit is concerned, a block is 512 bytes.

       umask [-S] [mask]
	      Display  or set the file permission creation mask, or umask (see umask(2)).  If the
	      -S option is used, the mask displayed or set is symbolic, otherwise it is an  octal

	      Symbolic masks are like those used by chmod(1):
	      in  which the first group of characters is the who part, the second group is the op
	      part, and the last group is the perm part.  The who part specifies  which  part  of
	      the umask is to be modified.  The letters mean:

		     u	    the user permissions

		     g	    the group permissions

		     o	    the other permissions (non-user, non-group)

		     a	    all permissions (user, group and other)

	      The op part indicates how the who permissions are to be modified:

		     =	    set

		     +	    added to

		     -	    removed from

	      The perm part specifies which permissions are to be set, added or removed:

		     r	    read permission

		     w	    write permission

		     x	    execute permission

	      When  symbolic masks are used, they describe what permissions may be made available
	      (as opposed to octal masks in which a set bit means the corresponding bit is to  be
	      cleared).   Example:  `ug=rwx,o='  sets  the  mask  so  files will not be readable,
	      writable or executable by `others', and is equivalent  (on  most	systems)  to  the
	      octal mask `07'.

       unalias [-adt] [name1 ...]
	      The aliases for the given names are removed.  If the -a option is used, all aliases
	      are removed.  If the -t or -d options are used, the indicated operations	are  car-
	      ried out on tracked or directory aliases, respectively.

       unset [-fv] parameter ...
	      Unset the named parameters (-v, the default) or functions (-f).  The exit status is
	      non-zero if any of the parameters were already unset, zero otherwise.

       wait [job]
	      Wait for the specified job(s) to finish.	The exit status of wait is  that  of  the
	      last specified job: if the last job is killed by a signal, the exit status is 128 +
	      the number of the signal (see kill -l exit-status above); if the last specified job
	      can't be found (because it never existed, or had already finished), the exit status
	      of wait is 127.  See Job Control below for the format of job.  Wait will return  if
	      a signal for which a trap has been set is received, or if a HUP, INT or QUIT signal
	      is received.

	      If no jobs are specified, wait waits for all currently running  jobs  (if  any)  to
	      finish  and exits with a zero status.  If job monitoring is enabled, the completion
	      status of jobs is printed (this is not the case when  jobs  are  explicitly  speci-

       whence [-pv] [name ...]
	      For each name, the type of command is listed (reserved word, built-in, alias, func-
	      tion, tracked alias or executable).  If the -p option is used, a path  search  done
	      even if name is a reserved word, alias, etc.  Without the -v option, whence is sim-
	      ilar to command -v except that whence will find  reserved  words	and  won't  print
	      aliases  as  alias  commands; with the -v option, whence is the same as command -V.
	      Note that for whence, the -p option does not affect the search  path  used,  as  it
	      does for command.  If the type of one or more of the names could not be determined,
	      the exit status is non-zero.

   Job Control
       Job control refers to the shell's ability to monitor and control jobs, which are processes
       or  groups  of processes created for commands or pipelines.  At a minimum, the shell keeps
       track of the status of the background (i.e., asynchronous) jobs that currently exist; this
       information  can  be  displayed	using  the jobs command.  If job control is fully enabled
       (using set -m or set -o monitor), as it is for interactive shells, the processes of a  job
       are  placed  in their own process group, foreground jobs can be stopped by typing the sus-
       pend character from the terminal (normally ^Z), jobs can be restarted in either the  fore-
       ground  or  background,	using  the fg and bg commands, respectively, and the state of the
       terminal is saved or restored when a foreground job is stopped or restarted, respectively.

       Note that only commands that create processes (e.g., asynchronous commands, subshell  com-
       mands,  and non-built-in, non-function commands) can be stopped; commands like read cannot

       When a job is created, it is assigned a job-number.  For interactive shells,  this  number
       is  printed  inside  [..], followed by the process-ids of the processes in the job when an
       asynchronous command is run.  A job may be referred to in bg, fg, jobs, kill and wait com-
       mands  either  by the process id of the last process in the command pipeline (as stored in
       the $! parameter) or by prefixing the job-number with a percent sign (%).   Other  percent
       sequences can also be used to refer to jobs:

	%+					    The  most  recently stopped job, or, if there
						    are no stopped jobs, the oldest running job.
	%%, %					    Same as %+.
	%-					    The job that would be  the	%+  job,  if  the
						    later did not exist.
	%n					    The job with job-number n.
	%?string				    The  job  containing  the  string  string (an
						    error occurs if multiple jobs are matched).
	%string 				    The job starting with string string (an error
						    occurs if multiple jobs are matched).

       When  a	job changes state (e.g., a background job finishes or foreground job is stopped),
       the shell prints the following status information:
	      [number] flag status command

	      is the job-number of the job.

	flag  is + or - if the job is the %+ or %- job, respectively, or space if it is neither.

	      indicates the current state of the job and can be

		     the job has neither stopped or exited (note that running does not	necessar-
		     ily mean consuming CPU time -- the process could be blocked waiting for some

	      Done [(number)]
		     the job exited.  number is the exit status of the job, which is  omitted  if
		     the status is zero.

	      Stopped [(signal)]
		     the  job was stopped by the indicated signal (if no signal is given, the job
		     was stopped by SIGTSTP).

	      signal-description [(core dumped)]
		     the job was killed by a signal (e.g., Memory fault, Hangup, etc. -- use kill
		     -l  for a list of signal descriptions).  The (core dumped) message indicates
		     the process created a core file.

	      is the command that created the process.	If there are multiple  processes  in  the
	      job,  then  each process will have a line showing its command and possibly its sta-
	      tus, if it is different from the status of the previous process.

       When an attempt is made to exit the shell while there are jobs in the stopped  state,  the
       shell warns the user that there are stopped jobs and does not exit.  If another attempt is
       immediately made to exit the shell, the stopped jobs are sent a HUP signal and  the  shell
       exits.	Similarly,  if	the  nohup  option  is not set and there are running jobs when an
       attempt is made to exit a login shell, the shell warns the user and  does  not  exit.   If
       another	attempt  is  immediately  made to exit the shell, the running jobs are sent a HUP
       signal and the shell exits.

   Interactive Input Line Editing
       The shell supports three modes of reading command lines from a tty in an interactive  ses-
       sion.   Which is used is controlled by the emacs, gmacs and vi set options (at most one of
       these can be set at once).  If none of these options is enabled, the  shell  simply  reads
       lines  using the normal tty driver.  If the emacs or gmacs option is set, the shell allows
       emacs like editing of the command; similarly, if the vi option is set, the shell allows vi
       like  editing  of  the command.	These modes are described in detail in the following sec-

       In these editing modes, if a line is longer that the screen width (see COLUMNS parameter),
       a >, + or < character is displayed in the last column indicating that there are more char-
       acters after, before and after, or before the current position, respectively.  The line is
       scrolled horizontally as necessary.

   Emacs Editing Mode
       When  the  emacs  option is set, interactive input line editing is enabled.  Warning: This
       mode is slightly different from the emacs mode in the original Korn shell and the 8th  bit
       is  stripped in emacs mode.  In this mode various editing commands (typically bound to one
       or more control characters) cause immediate actions without waiting for a new-line.   Sev-
       eral  editing  commands	are  bound  to	particular  control  characters when the shell is
       invoked; these bindings can be changed using the following commands:

       bind   The current bindings are listed.

       bind string=[editing-command]
	      The specified editing command is bound to the given string, which should consist of
	      a control character (which may be written using caret notation ^X), optionally pre-
	      ceded by one of the two prefix characters.  Future input of the string  will  cause
	      the  editing command to be immediately invoked.  Note that although only two prefix
	      characters (usually ESC and ^X) are supported, some multi-character  sequences  can
	      be  supported.   The  following  binds the arrow keys on an ANSI terminal, or xterm
	      (these are in the default bindings).  Of course some escape  sequences  won't  work
	      out quite this nicely:

	      bind '^[['=prefix-2
	      bind '^XA'=up-history
	      bind '^XB'=down-history
	      bind '^XC'=forward-char
	      bind '^XD'=backward-char

       bind -l
	      Lists the names of the functions to which keys may be bound.

       bind -m string=[substitute]
	      The  specified  input  string  will afterwards be immediately replaced by the given
	      substitute string, which may contain editing commands.

       The following is a list of editing commands available.  Each description starts	with  the
       name  of  the  command, a n, if the command can be prefixed with a count, and any keys the
       command is bound to by default (written using caret notation, e.g., ASCII ESC character is
       written	as  ^[).  A count prefix for a command is entered using the sequence ^[n, where n
       is a sequence of 1 or more digits; unless otherwise specified, if a count is  omitted,  it
       defaults to 1.  Note that editing command names are used only with the bind command.  Fur-
       thermore, many editing commands are useful only on terminals with a visible  cursor.   The
       default	bindings were chosen to resemble corresponding EMACS key bindings.  The users tty
       characters (e.g., ERASE) are bound to reasonable  substitutes  and  override  the  default

       abort ^G
	      Useful  as  a  response to a request for a search-history pattern in order to abort
	      the search.

       auto-insert n
	      Simply causes the character to appear as literal input.  Most  ordinary  characters
	      are bound to this.

       backward-char  n ^B
	      Moves the cursor backward n characters.

       backward-word  n ^[B
	      Moves  the cursor backward to the beginning of a word; words consist of alphanumer-
	      ics, underscore (_) and dollar ($).

       beginning-of-history ^[<
	      Moves to the beginning of the history.

       beginning-of-line ^A
	      Moves the cursor to the beginning of the edited input line.

       capitalize-word n ^[c, ^[C
	      Uppercase the first character in the next n words, leaving the cursor past the  end
	      of the last word.  If the current line does not begin with a comment character, one
	      is added at the beginning of the line and the line is entered  (as  if  return  had
	      been pressed), otherwise the existing comment characters are removed and the cursor
	      is placed at the beginning of the line.

       complete ^[^[

       complete ^I
	      Automatically completes as much as is unique of the command name or the  file  name
	      containing  the  cursor.	 If the entire remaining command or file name is unique a
	      space is printed after its completion, unless it is a directory name in which  case
	      /  is  appended.	If there is no command or file name with the current partial word
	      as its prefix, a bell character is output (usually causing a audio beep).

       complete-command ^X^[
	      Automatically completes as much as is unique of the command name having the partial
	      word up to the cursor as its prefix, as in the complete command described above.

       complete-file ^[^X
	      Automatically  completes	as  much as is unique of the file name having the partial
	      word up to the cursor as its prefix, as in the complete command described above.

       complete-list ^[=
	      List the possible completions for the current word.

       delete-char-backward n ERASE, ^?, ^H
	      Deletes n characters before the cursor.

       delete-char-forward n
	      Deletes n characters after the cursor.

       delete-word-backward n ^[ERASE, ^[^?, ^[^H, ^[h
	      Deletes n words before the cursor.

       delete-word-forward n ^[d
	      Deletes characters after the cursor up to the end of n words.

       down-history n ^N
	      Scrolls the history buffer forward n lines (later).   Each  input  line  originally
	      starts just after the last entry in the history buffer, so down-history is not use-
	      ful until either search-history or up-history has been performed.

       downcase-word n ^[L, ^[l
	      Lowercases the next n words.

       end-of-history ^[>
	      Moves to the end of the history.

       end-of-line ^E
	      Moves the cursor to the end of the input line.

       eot ^_ Acts as an end-of-file; this is useful because edit-mode input disables normal ter-
	      minal input canonicalization.

       eot-or-delete n ^D
	      Acts as eot if alone on a line; otherwise acts as delete-char-forward.

       error  Error (ring the bell).

       exchange-point-and-mark ^X^X
	      Places the cursor where the mark is, and sets the mark to where the cursor was.

       expand-file ^[*
	      Appends a * to the current word and replaces the word with the result of performing
	      file globbing on the word.  If no files match the pattern, the bell is rung.

       forward-char n ^F
	      Moves the cursor forward n characters.

       forward-word n ^[f
	      Moves the cursor forward to the end of the nth word.

       goto-history n ^[g
	      Goes to history number n.

       kill-line KILL
	      Deletes the entire input line.

       kill-region ^W
	      Deletes the input between the cursor and the mark.

       kill-to-eol n ^K
	      Deletes the input from the cursor to the end of the line if  n  is  not  specified,
	      otherwise deletes characters between the cursor and column n.

       list ^[?
	      Prints  a  sorted, columnated list of command names or file names (if any) that can
	      complete the partial word containing the cursor.	Directory names have  /  appended
	      to them.

       list-command ^X?
	      Prints  a  sorted,  columnated list of command names (if any) that can complete the
	      partial word containing the cursor.

       list-file ^X^Y
	      Prints a sorted, columnated list of file names (if any) that can complete the  par-
	      tial  word  containing  the cursor.  File type indicators are appended as described
	      under list above.

       newline ^J, ^M
	      Causes the current input line to be processed by the  shell.   The  current  cursor
	      position may be anywhere on the line.

       newline-and-next ^O
	      Causes  the current input line to be processed by the shell, and the next line from
	      history becomes the current line.  This is  only	useful	after  an  up-history  or

       no-op QUIT
	      This does nothing.

       prefix-1 ^[
	      Introduces a 2-character command sequence.

       prefix-2 ^X

       prefix-2 ^[[
	      Introduces a 2-character command sequence.

       prev-hist-word n ^[., ^[_
	      The last (nth) word of the previous command is inserted at the cursor.

       quote ^^
	      The following character is taken literally rather than as an editing command.

       redraw ^L
	      Reprints the prompt string and the current input line.

       search-character-backward n ^[^]
	      Search  backward	in  the current line for the nth occurrence of the next character

       search-character-forward n ^]
	      Search forward in the current line for the nth occurrence  of  the  next	character

       search-history ^R
	      Enter incremental search mode.  The internal history list is searched backwards for
	      commands matching the input.  An initial ^ in the search string anchors the search.
	      The  abort key will leave search mode.  Other commands will be executed after leav-
	      ing search mode.	Successive search-history commands continue searching backward to
	      the  next  previous  occurrence  of the pattern.	The history buffer retains only a
	      finite number of lines; the oldest are discarded as necessary.

       set-mark-command ^[<space>
	      Set the mark at the cursor position.

       stuff  On systems supporting it, pushes the bound character back onto the  terminal  input
	      where  it  may  receive special processing by the terminal handler.  This is useful
	      for the BRL ^T mini-systat feature, for example.

	      Acts like stuff, then aborts input the same as an interrupt.

       transpose-chars ^T
	      If at the end of line, or if the gmacs option is set, this exchanges the two previ-
	      ous  characters;	otherwise,  it	exchanges the previous and current characters and
	      moves the cursor one character to the right.

       up-history n ^P
	      Scrolls the history buffer backward n lines (earlier).

       upcase-word n ^[U, ^[u
	      Uppercases the next n words.

       version ^V
	      Display the version of ksh.  The current edit buffer is restored as soon as any key
	      is pressed (the key is then processed, unless it is a space).

       yank ^Y
	      Inserts the most recently killed text string at the current cursor position.

       yank-pop ^[y
	      Immediately  after a yank, replaces the inserted text string with the next previous
	      killed text string.

   Vi Editing Mode
       The vi command line editor in ksh has basically the same commands as the  vi  editor  (see
       vi(1)), with the following exceptions:

	 o    you start out in insert mode,

	 o    there  are  file	name  and  command  completion commands (=, \, *, ^X, ^E, ^F and,
	      optionally, <tab>),

	 o    the _ command is different (in ksh it is the last argument command, in vi  it  goes
	      to the start of the current line),

	 o    the / and G commands move in the opposite direction as the j command

	 o    and  commands  which  don't  make  sense	in a single line editor are not available
	      (e.g., screen movement commands, ex : commands, etc.).

       Note that the ^X stands for control-X; also <esc>, <space> and <tab> are used for  escape,
       space and tab, respectively (no kidding).

       Like  vi, there are two modes: insert mode and command mode.  In insert mode, most charac-
       ters are simply put in the buffer at the current cursor position as they are  typed,  how-
       ever,  some characters are treated specially.  In particular, the following characters are
       taken from current tty settings (see stty(1)) and have their usual meaning (normal  values
       are  in	parentheses):  kill  (^U),  erase (^?), werase (^W), eof (^D), intr (^C) and quit
       (^\).  In addition to the above, the following characters are also  treated  specially  in
       insert mode:

	^H					    erases previous character
	^V					    literal next: the next character typed is not
						    treated specially (can be used to insert  the
						    characters being described here)
	^J ^M					    end of line: the current line is read, parsed
						    and executed by the shell
	<esc>					    puts the editor in command mode (see below)
	^E					    command and file name enumeration (see below)
	^F					    command and file name completion (see below).
						    If	used twice in a row, the list of possible
						    completions is displayed;  if  used  a  third
						    time, the completion is undone.
	^X					    command and file name expansion (see below)
	<tab>					    optional  file  name  and  command completion
						    (see ^F above), enabled with set  -o  vi-tab-

       In command mode, each character is interpreted as a command.  Characters that don't corre-
       spond to commands, are illegal combinations of commands or are commands that can't be car-
       ried  out  all cause beeps.  In the following command descriptions, a n indicates the com-
       mand may be prefixed by a number (e.g., 10l moves right 10 characters); if no number  pre-
       fix is used, n is assumed to be 1 unless otherwise specified.  The term `current position'
       refers to the position between the cursor and  the  character  preceding  the  cursor.	A
       `word'  is  a  sequence of letters, digits and underscore characters or a sequence of non-
       letter, non-digit, non-underscore, non-white-space characters (e.g., ab2*&^  contains  two
       words) and a `big-word' is a sequence of non-white-space characters.

       Special ksh vi commands
	      The  following  commands are not in, or are different from, the normal vi file edi-

	      n_     insert a space followed by the nth big-word from the  last  command  in  the
		     history  at  the  current position and enter insert mode; if n is not speci-
		     fied, the last word is inserted.

	      #      insert the comment character (#) at the start of the current line and return
		     the line to the shell (equivalent to I#^J).

	      ng     like  G, except if n is not specified, it goes to the most recent remembered

	      nv     edit line n using the vi editor; if n is not specified, the current line  is
		     edited.  The actual command executed is `fc -e ${VISUAL:-${EDITOR:-vi}} n'.

	      * and ^X
		     command  or  file name expansion is applied to the current big-word (with an
		     appended *, if the word contains no file globing characters) - the  big-word
		     is  replaced with the resulting words.  If the current big-word is the first
		     on the line (or follows one of the following characters: ;, |, &, (, ))  and
		     does  not contain a slash (/) then command expansion is done, otherwise file
		     name expansion is done.  Command expansion will match the	big-word  against
		     all aliases, functions and built-in commands as well as any executable files
		     found by searching the directories in the PATH parameter.	File name  expan-
		     sion matches the big-word against the files in the current directory.  After
		     expansion, the cursor is placed just past the last word and the editor is in
		     insert mode.

	      n\, n^F, n<tab> and n<esc>
		     command/file  name completion: replace the current big-word with the longest
		     unique match obtained after performing command/file name  expansion.   <tab>
		     is  only recognized if the vi-tabcomplete option is set, while <esc> is only
		     recognized if the vi-esccomplete option is set (see set -o).  If n is speci-
		     fied,  the  nth  possible	completion  is	selected (as reported by the com-
		     mand/file name enumeration command).

	      = and ^E
		     command/file name enumeration: list all the commands or files that match the
		     current big-word.

	      ^V     display  the  version of pdksh; it is displayed until another key is pressed
		     (this key is ignored).

	      @c     macro expansion: execute the commands found in the alias _c.

       Intra-line movement commands

	      nh and n^H
		     move left n characters.

	      nl and n<space>
		     move right n characters.

	      0      move to column 0.

	      ^      move to the first non white-space character.

	      n|     move to column n.

	      $      move to the last character.

	      nb     move back n words.

	      nB     move back n big-words.

	      ne     move forward to the end the word, n times.

	      nE     move forward to the end the big-word, n times.

	      nw     move forward n words.

	      nW     move forward n big-words.

	      %      find match: the editor looks forward for the nearest parenthesis, bracket or
		     brace and then moves the to the matching parenthesis, bracket or brace.

	      nfc    move forward to the nth occurrence of the character c.

	      nFc    move backward to the nth occurrence of the character c.

	      ntc    move forward to just before the nth occurrence of the character c.

	      nTc    move backward to just before the nth occurrence of the character c.

	      n;     repeats the last f, F, t or T command.

	      n,     repeats the last f, F, t or T command, but moves in the opposite direction.

       Inter-line movement commands

	      nj and n+ and n^N
		     move to the nth next line in the history.

	      nk and n- and n^P
		     move to the nth previous line in the history.

	      nG     move  to  line  n	in  the  history; if n is not specified, the number first
		     remembered line is used.

	      ng     like G, except if n is not specified, it goes to the most recent  remembered

		     search  backward  through the history for the nth line containing string; if
		     string starts with ^, the remainder of the string must appear at  the  start
		     of the history line for it to match.

		     same as /, except it searches forward through the history.

	      nn     search  for  the  nth occurrence of the last search string; the direction of
		     the search is the same as the last search.

	      nN     search for the nth occurrence of the last search string;  the  direction  of
		     the search is the opposite of the last search.

       Edit commands

	      na     append  text n times: goes into insert mode just after the current position.
		     The append is only replicated if command mode is re-entered (i.e., <esc>  is

	      nA     same as a, except it appends at the end of the line.

	      ni     insert  text  n  times:  goes into insert mode at the current position.  The
		     insertion is only replicated if command mode is re-entered (i.e.,	<esc>  is

	      nI     same  as  i,  except  the	insertion is done just before the first non-blank

	      ns     substitute the next n characters (i.e., delete the characters  and  go  into
		     insert mode).

	      S      substitute  whole line: all characters from the first non-blank character to
		     the end of line are deleted and insert mode is entered.

		     change from the current position to the position resulting from n	move-cmds
		     (i.e.,  delete the indicated region and go into insert mode); if move-cmd is
		     c, the line starting from the first non-blank character is changed.

	      C      change from the current position to the end of the line (i.e., delete to the
		     end of the line and go into insert mode).

	      nx     delete the next n characters.

	      nX     delete the previous n characters.

	      D      delete to the end of the line.

		     delete from the current position to the position resulting from n move-cmds;
		     move-cmd is a movement command (see above) or d, in which case  the  current
		     line is deleted.

	      nrc    replace the next n characters with the character c.

	      nR     replace:  enter  insert  mode  but  overwrite existing characters instead of
		     inserting before existing characters.  The replacement is repeated n times.

	      n~     change the case of the next n characters.

		     yank from the current position to the position resulting  from  n	move-cmds
		     into the yank buffer; if move-cmd is y, the whole line is yanked.

	      Y      yank from the current position to the end of the line.

	      np     paste  the  contents  of  the yank buffer just after the current position, n

	      nP     same as p, except the buffer is pasted at the current position.

       Miscellaneous vi commands

	      ^J and ^M
		     the current line is read, parsed and executed by the shell.

	      ^L and ^R
		     redraw the current line.

	      n.     redo the last edit command n times.

	      u      undo the last edit command.

	      U      undo all changes that have been made to the current line.

	      intr and quit
		     the interrupt and quit terminal characters cause  the  current  line  to  be
		     deleted and a new prompt to be printed.


       Any  bugs  in  pdksh should be reported to pdksh@cs.mun.ca.  Please include the version of
       pdksh (echo $KSH_VERSION shows it), the machine, operating system  and  compiler  you  are
       using  and  a description of how to repeat the bug (a small shell script that demonstrates
       the bug is best).  The following, if relevant (if you are not  sure,  include  them),  can
       also helpful: options you are using (both options.h options and set -o options) and a copy
       of your config.h (the file generated by the configure script).  New versions of pdksh  can
       be obtained from ftp://ftp.cs.mun.ca/pub/pdksh/.

       BTW, the most frequently reported bug is
	       echo hi | read a; echo $a   # Does not print hi
       I'm aware of this and there is no need to report it.

       This page documents version
				      @(#)PD KSH v5.2.14 99/07/13.2
       of the public domain korn shell.

       This shell is based on the public domain 7th edition Bourne shell clone by Charles Forsyth
       and parts of the BRL shell by Doug A. Gwyn, Doug Kingston, Ron  Natalie,  Arnold  Robbins,
       Lou  Salkind and others.  The first release of pdksh was created by Eric Gisin, and it was
       subsequently maintained by John R. MacMillan (chance!john@sq.sq.com), and Simon J. Gerraty
       (sjg@zen.void.oz.au).  The current maintainer is Michael Rendell (michael@cs.mun.ca).  The
       CONTRIBUTORS file in the source distribution contains a more complete list of  people  and
       their part in the shell's development.

       awk(1),	sh(1),	csh(1),  ed(1),  getconf(1),  getopt(1),  sed(1), stty(1), vi(1), dup(2),
       execve(2), getgid(2), getuid(2), open(2), pipe(2), wait(2), getopt(3), rand(3), signal(3),
       system(3), environ(7)

       The  KornShell  Command and Programming Language, Morris Bolsky and David Korn, 1989, ISBN

       UNIX Shell Programming, Stephen G. Kochan, Patrick H. Wood, Hayden.

       IEEE Standard for information Technology - Portable Operating System Interface  (POSIX)	-
       Part 2: Shell and Utilities, IEEE Inc, 1993, ISBN 1-55937-255-9.

					 August 19, 1996				   KSH(1)

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