Provided by: zsh-common_5.1.1-1ubuntu2_all bug

NAME

       zshmodules - zsh loadable modules

DESCRIPTION

       Some  optional  parts of zsh are in modules, separate from the core of the shell.  Each of
       these modules may be linked in to the shell at build time, or can  be  dynamically  linked
       while  the shell is running if the installation supports this feature.  Modules are linked
       at runtime with the zmodload command, see zshbuiltins(1).

       The modules that are bundled with the zsh distribution are:

       zsh/attr
              Builtins for manipulating extended attributes (xattr).

       zsh/cap
              Builtins for manipulating POSIX.1e (POSIX.6) capability (privilege) sets.

       zsh/clone
              A builtin that can clone a running shell onto another terminal.

       zsh/compctl
              The compctl builtin for controlling completion.

       zsh/complete
              The basic completion code.

       zsh/complist
              Completion listing extensions.

       zsh/computil
              A module with utility builtins needed  for  the  shell  function  based  completion
              system.

       zsh/curses
              curses windowing commands

       zsh/datetime
              Some date/time commands and parameters.

       zsh/db/gdbm
              Builtins for managing associative array parameters tied to GDBM databases.

       zsh/deltochar
              A ZLE function duplicating EMACS' zap-to-char.

       zsh/example
              An example of how to write a module.

       zsh/files
              Some basic file manipulation commands as builtins.

       zsh/langinfo
              Interface to locale information.

       zsh/mapfile
              Access to external files via a special associative array.

       zsh/mathfunc
              Standard scientific functions for use in mathematical evaluations.

       zsh/newuser
              Arrange for files for new users to be installed.

       zsh/parameter
              Access to internal hash tables via special associative arrays.

       zsh/pcre
              Interface to the PCRE library.

       zsh/regex
              Interface to the POSIX regex library.

       zsh/sched
              A builtin that provides a timed execution facility within the shell.

       zsh/net/socket
              Manipulation of Unix domain sockets

       zsh/stat
              A builtin command interface to the stat system call.

       zsh/system
              A builtin interface to various low-level system features.

       zsh/net/tcp
              Manipulation of TCP sockets

       zsh/termcap
              Interface to the termcap database.

       zsh/terminfo
              Interface to the terminfo database.

       zsh/zftp
              A builtin FTP client.

       zsh/zle
              The Zsh Line Editor, including the bindkey and vared builtins.

       zsh/zleparameter
              Access to internals of the Zsh Line Editor via parameters.

       zsh/zprof
              A module allowing profiling for shell functions.

       zsh/zpty
              A builtin for starting a command in a pseudo-terminal.

       zsh/zselect
              Block and return when file descriptors are ready.

       zsh/zutil
              Some utility builtins, e.g. the one for supporting configuration via styles.

THE ZSH/ATTR MODULE

       The  zsh/attr  module  is used for manipulating extended attributes.  The -h option causes
       all commands to operate on symbolic links instead of their targets.  The builtins in  this
       module are:

       zgetattr [ -h ] filename attribute [ parameter ]
              Get  the  extended attribute attribute from the specified filename. If the optional
              argument parameter is given, the attribute is set  on  that  parameter  instead  of
              being printed to stdout.

       zsetattr [ -h ] filename attribute value
              Set the extended attribute attribute on the specified filename to value.

       zdelattr [ -h ] filename attribute
              Remove the extended attribute attribute from the specified filename.

       zlistattr [ -h ] filename [ parameter ]
              List  the  extended  attributes  currently  set  on  the specified filename. If the
              optional argument parameter is given,  the  list  of  attributes  is  set  on  that
              parameter instead of being printed to stdout.

       zgetattr  and  zlistattr  allocate  memory  dynamically.   If  the  attribute  or  list of
       attributes grows between the allocation and the call to get them, they return 2.   On  all
       other  errors, 1 is returned.  This allows the calling function to check for this case and
       retry.

THE ZSH/CAP MODULE

       The zsh/cap module is used for manipulating POSIX.1e (POSIX.6) capability  sets.   If  the
       operating system does not support this interface, the builtins defined by this module will
       do nothing.  The builtins in this module are:

       cap [ capabilities ]
              Change the shell's process capability sets to the specified capabilities, otherwise
              display the shell's current capabilities.

       getcap filename ...
              This  is  a built-in implementation of the POSIX standard utility.  It displays the
              capability sets on each specified filename.

       setcap capabilities filename ...
              This is a built-in implementation of the  POSIX  standard  utility.   It  sets  the
              capability sets on each specified filename to the specified capabilities.

THE ZSH/CLONE MODULE

       The zsh/clone module makes available one builtin command:

       clone tty
              Creates  a forked instance of the current shell, attached to the specified tty.  In
              the new shell, the PID, PPID and TTY special parameters are changed  appropriately.
              $!  is  set  to  zero  in the new shell, and to the new shell's PID in the original
              shell.

              The return status of the builtin is zero in both shells if successful, and non-zero
              on error.

              The target of clone should be an unused terminal, such as an unused virtual console
              or a virtual terminal created by

                     xterm -e sh -c 'trap : INT QUIT TSTP; tty;
                             while :; do sleep 100000000; done'

              Some words of explanation are warranted about this long xterm  command  line:  when
              doing  clone  on  a  pseudo-terminal, some other session ("session" meant as a unix
              session group, or SID) is already owning the terminal. Hence the cloned zsh  cannot
              acquire the pseudo-terminal as a controlling tty. That means two things:

              ·      the  job  control  signals  will go to the sh-started-by-xterm process group
                     (that's why we disable INT QUIT and TSTP with trap; otherwise the while loop
                     could get suspended or killed)

              ·      the  cloned  shell  will have job control disabled, and the job control keys
                     (control-C, control-\ and control-Z) will not work.

              This does not apply when cloning to an unused vc.

              Cloning to a used (and unprepared) terminal will result in  two  processes  reading
              simultaneously  from  the  same terminal, with input bytes going randomly to either
              process.

              clone is mostly useful as a shell built-in replacement for openvt.

THE ZSH/COMPCTL MODULE

       The zsh/compctl module  makes  available  two  builtin  commands.  compctl,  is  the  old,
       deprecated  way  to  control  completions  for ZLE.  See zshcompctl(1).  The other builtin
       command, compcall can be used in user-defined completion widgets, see zshcompwid(1).

THE ZSH/COMPLETE MODULE

       The zsh/complete module makes available several builtin commands  which  can  be  used  in
       user-defined completion widgets, see zshcompwid(1).

THE ZSH/COMPLIST MODULE

       The  zsh/complist  module  offers  three extensions to completion listings: the ability to
       highlight matches in such a list, the ability to scroll through long lists and a different
       style of menu completion.

   Colored completion listings
       Whenever  one  of  the  parameters  ZLS_COLORS  or ZLS_COLOURS is set and the zsh/complist
       module is loaded or linked into the  shell,  completion  lists  will  be  colored.   Note,
       however,  that  complist  will  not  automatically  be  loaded if it is not linked in:  on
       systems with dynamic loading, `zmodload zsh/complist' is required.

       The parameters ZLS_COLORS and ZLS_COLOURS describe how matches are highlighted.   To  turn
       on  highlighting an empty value suffices, in which case all the default values given below
       will be used.  The format of the value of these parameters is the same as used by the  GNU
       version  of  the  ls  command:  a  colon-separated  list  of  specifications  of  the form
       `name=value'.  The name may be one of the following strings, most of  which  specify  file
       types for which the value will be used.  The strings and their default values are:

       no 0   for normal text (i.e. when displaying something other than a matched file)

       fi 0   for regular files

       di 32  for directories

       ln 36  for  symbolic  links.   If  this  has  the special value target, symbolic links are
              dereferenced and the target file used to determine the display format.

       pi 31  for named pipes (FIFOs)

       so 33  for sockets

       bd 44;37
              for block devices

       cd 44;37
              for character devices

       or none
              for a symlink to nonexistent file (default is the value defined for ln)

       mi none
              for a non-existent file (default is  the  value  defined  for  fi);  this  code  is
              currently not used

       su 37;41
              for files with setuid bit set

       sg 30;43
              for files with setgid bit set

       tw 30;42
              for world writable directories with sticky bit set

       ow 34;43
              for world writable directories without sticky bit set

       sa none
              for  files  with  an  associated  suffix  alias; this is only tested after specific
              suffixes, as described below

       st 37;44
              for directories with sticky bit set but not world writable

       ex 35  for executable files

       lc \e[ for the left code (see below)

       rc m   for the right code

       tc 0   for the character  indicating  the  file  type   printed  after  filenames  if  the
              LIST_TYPES option is set

       sp 0   for the spaces printed after matches to align the next column

       ec none
              for the end code

       Apart  from  these strings, the name may also be an asterisk (`*') followed by any string.
       The value given for such a string will be used for all files  whose  name  ends  with  the
       string.   The  name  may  also  be  an  equals  sign  (`=')  followed  by  a  pattern; the
       EXTENDED_GLOB option will be turned on for evaluation of the pattern.  The value given for
       this  pattern  will  be used for all matches (not just filenames) whose display string are
       matched by the pattern.  Definitions for  the  form  with  the  leading  equal  sign  take
       precedence  over the values defined for file types, which in turn take precedence over the
       form with the leading asterisk (file extensions).

       The leading-equals form also allows different parts of the displayed strings to be colored
       differently.   For  this,  the  pattern  has  to use the `(#b)' globbing flag and pairs of
       parentheses surrounding the parts of the strings that are to be colored  differently.   In
       this case the value may consist of more than one color code separated by equal signs.  The
       first code will be used for all parts for which no explicit  code  is  specified  and  the
       following  codes  will  be  used for the parts matched by the sub-patterns in parentheses.
       For example, the specification `=(#b)(?)*(?)=0=3=7' will be used for all matches which are
       at  least  two  characters long and will use the code `3' for the first character, `7' for
       the last character and `0' for the rest.

       All three forms of name may be preceded by a pattern in parentheses.  If  this  is  given,
       the  value  will be used only for matches in groups whose names are matched by the pattern
       given in the parentheses.  For example, `(g*)m*=43' highlights all matches beginning  with
       `m' in groups whose names  begin with `g' using the color code `43'.  In case of the `lc',
       `rc', and `ec' codes, the group pattern is ignored.

       Note also that all patterns are tried in the order in which they appear in  the  parameter
       value until the first one matches which is then used.

       When printing a match, the code prints the value of lc, the value for the file-type or the
       last matching specification with a `*', the value of rc, the string  to  display  for  the
       match  itself, and then the value of ec if that is defined or the values of lc, no, and rc
       if ec is not defined.

       The default values are ISO 6429 (ANSI) compliant and  can  be  used  on  vt100  compatible
       terminals such as xterms.  On monochrome terminals the default values will have no visible
       effect.  The colors function from the contribution can be used to get  associative  arrays
       containing   the   codes  for  ANSI  terminals  (see  the  section  `Other  Functions'  in
       zshcontrib(1)).  For example, after loading colors, one could use  `$colors[red]'  to  get
       the  code  for  foreground  color  red and `$colors[bg-green]' for the code for background
       color green.

       If the completion system invoked by compinit is used, these parameters should not  be  set
       directly  because  the system controls them itself.  Instead, the list-colors style should
       be used (see the section `Completion System Configuration' in zshcompsys(1)).

   Scrolling in completion listings
       To enable scrolling through a completion list, the LISTPROMPT parameter must be set.   Its
       value  will  be  used  as  the prompt; if it is the empty string, a default prompt will be
       used.  The value may contain escapes of the form `%x'.   It  supports  the  escapes  `%B',
       `%b',  `%S',  `%s',  `%U',  `%u',  `%F', `%f', `%K', `%k' and `%{...%}' used also in shell
       prompts as well as three pairs of additional sequences: a `%l' or `%L' is replaced by  the
       number  of the last line shown and the total number of lines in the form `number/total'; a
       `%m' or `%M' is replaced with the number of the last match shown and the total  number  of
       matches;  and  `%p'  or `%P' is replaced with `Top', `Bottom' or the position of the first
       line shown in percent of the total number of lines, respectively.  In each of these  cases
       the  form  with the uppercase letter will be replaced with a string of fixed width, padded
       to the right with spaces, while the lowercase form will not be padded.

       If the parameter LISTPROMPT is set, the completion code will not ask if the list should be
       shown.   Instead  it  immediately  starts  displaying  the  list, stopping after the first
       screenful, showing the prompt at the bottom, waiting  for  a  keypress  after  temporarily
       switching  to  the  listscroll  keymap.   Some of the zle functions have a special meaning
       while scrolling lists:

       send-break
              stops listing discarding the key pressed

       accept-line, down-history, down-line-or-history
       down-line-or-search, vi-down-line-or-history
              scrolls forward one line

       complete-word, menu-complete, expand-or-complete
       expand-or-complete-prefix, menu-complete-or-expand
              scrolls forward one screenful

       accept-search
              stop listing but take no other action

       Every other character stops listing and immediately processes the key as usual.   Any  key
       that  is not bound in the listscroll keymap or that is bound to undefined-key is looked up
       in the keymap currently selected.

       As for the ZLS_COLORS and ZLS_COLOURS parameters, LISTPROMPT should not  be  set  directly
       when  using  the  shell  function based completion system.  Instead, the list-prompt style
       should be used.

   Menu selection
       The zsh/complist module also offers an alternative style of selecting matches from a list,
       called  menu  selection,  which  can  be used if the shell is set up to return to the last
       prompt  after  showing  a  completion  list  (see   the   ALWAYS_LAST_PROMPT   option   in
       zshoptions(1)).

       Menu  selection  can be invoked directly by the widget menu-select defined by this module.
       This is a standard ZLE widget that can be bound to a key in the usual way as described  in
       zshzle(1).

       Alternatively,  the parameter MENUSELECT can be set to an integer, which gives the minimum
       number of matches that must be present before menu selection is automatically  turned  on.
       This second method requires that menu completion be started, either directly from a widget
       such as menu-complete, or due to one of the options MENU_COMPLETE or AUTO_MENU being  set.
       If  MENUSELECT  is set, but is 0, 1 or empty, menu selection will always be started during
       an ambiguous menu completion.

       When using the completion system based on shell functions, the MENUSELECT parameter should
       not  be  used  (like the ZLS_COLORS and ZLS_COLOURS parameters described above).  Instead,
       the menu style should be used with the select=... keyword.

       After menu selection is started, the matches will be listed. If  there  are  more  matches
       than fit on the screen, only the first screenful is shown.  The matches to insert into the
       command line can be selected from this list.  In the list one match is  highlighted  using
       the value for ma from the ZLS_COLORS or ZLS_COLOURS parameter.  The default value for this
       is `7' which forces the selected  match  to  be  highlighted  using  standout  mode  on  a
       vt100-compatible  terminal.   If  neither  ZLS_COLORS  nor  ZLS_COLOURS  is  set, the same
       terminal control sequence as for the `%S' escape in prompts is used.

       If there are more matches than fit on the screen and the parameter MENUPROMPT is set,  its
       value  will  be  shown  below  the  matches.   It  supports  the  same escape sequences as
       LISTPROMPT, but the number of the match or line shown will be that of the  one  where  the
       mark is placed.  If its value is the empty string, a default prompt will be used.

       The  MENUSCROLL  parameter  can  be  used  to  specify  how  the list is scrolled.  If the
       parameter is unset, this is done line by line, if it is set to `0' (zero), the  list  will
       scroll  half  the  number  of lines of the screen.  If the value is positive, it gives the
       number of lines to scroll and if it is negative, the list will be scrolled the  number  of
       lines of the screen minus the (absolute) value.

       As  for  the  ZLS_COLORS,  ZLS_COLOURS  and  LISTPROMPT parameters, neither MENUPROMPT nor
       MENUSCROLL should be set directly when using the shell function based  completion  system.
       Instead, the select-prompt and select-scroll styles should be used.

       The  completion  code sometimes decides not to show all of the matches in the list.  These
       hidden matches are either matches for which  the  completion  function  which  added  them
       explicitly  requested that they not appear in the list (using the -n option of the compadd
       builtin command) or they are matches which duplicate a string already in the list (because
       they differ only in things like prefixes or suffixes that are not displayed).  In the list
       used for menu selection, however, even these matches are shown so that it is  possible  to
       select  them.   To highlight such matches the hi and du capabilities in the ZLS_COLORS and
       ZLS_COLOURS parameters are supported for hidden matches of  the  first  and  second  kind,
       respectively.

       Selecting  matches  is  done  by  moving the mark around using the zle movement functions.
       When not all matches can be shown on the screen at the same time, the list will scroll  up
       and  down  when crossing the top or bottom line.  The following zle functions have special
       meaning during menu selection.  Note that the  following  always  perform  the  same  task
       within  the menu selection map and cannot be replaced by user defined widgets, nor can the
       set of functions be extended:

       accept-line, accept-search
              accept the current match and leave menu selection (but do  not  cause  the  command
              line to be accepted)

       send-break
              leaves menu selection and restores the previous contents of the command line

       redisplay, clear-screen
              execute their normal function without leaving menu selection

       accept-and-hold, accept-and-menu-complete
              accept  the  currently inserted match and continue selection allowing to select the
              next match to insert into the line

       accept-and-infer-next-history
              accepts the current match and then tries completion with menu selection again;   in
              the  case of files this allows one to select a directory and immediately attempt to
              complete files in it;  if there are no matches, a message is shown and one can  use
              undo  to  go  back to completion on the previous level, every other key leaves menu
              selection (including the other zle functions which  are  otherwise  special  during
              menu selection)

       undo   removes  matches  inserted  during the menu selection by one of the three functions
              before

       down-history, down-line-or-history
       vi-down-line-or-history,  down-line-or-search
              moves the mark one line down

       up-history, up-line-or-history
       vi-up-line-or-history, up-line-or-search
              moves the mark one line up

       forward-char, vi-forward-char
              moves the mark one column right

       backward-char, vi-backward-char
              moves the mark one column left

       forward-word, vi-forward-word
       vi-forward-word-end, emacs-forward-word
              moves the mark one screenful down

       backward-word, vi-backward-word, emacs-backward-word
              moves the mark one screenful up

       vi-forward-blank-word, vi-forward-blank-word-end
              moves the mark to the first line of the next group of matches

       vi-backward-blank-word
              moves the mark to the last line of the previous group of matches

       beginning-of-history
              moves the mark to the first line

       end-of-history
              moves the mark to the last line

       beginning-of-buffer-or-history, beginning-of-line
       beginning-of-line-hist, vi-beginning-of-line
              moves the mark to the leftmost column

       end-of-buffer-or-history, end-of-line
       end-of-line-hist, vi-end-of-line
              moves the mark to the rightmost column

       complete-word, menu-complete, expand-or-complete
       expand-or-complete-prefix, menu-expand-or-complete
              moves the mark to the next match

       reverse-menu-complete
              moves the mark to the previous match

       vi-insert
              this toggles between normal and interactive mode;  in  interactive  mode  the  keys
              bound  to  self-insert  and  self-insert-unmeta  insert into the command line as in
              normal editing mode but  without  leaving  menu  selection;  after  each  character
              completion is tried again and the list changes to contain only the new matches; the
              completion widgets make the longest unambiguous string be inserted in  the  command
              line and undo and backward-delete-char go back to the previous set of matches

       history-incremental-search-forward
       history-incremental-search-backward
              this  starts  incremental  searches  in  the list of completions displayed; in this
              mode, accept-line only leaves incremental search, going back  to  the  normal  menu
              selection mode

       All  movement functions wrap around at the edges; any other zle function not listed leaves
       menu selection and executes that function.  It is possible to make widgets  in  the  above
       list  do  the  same by using the form of the widget with a `.' in front.  For example, the
       widget `.accept-line' has the effect of leaving menu selection and  accepting  the  entire
       command line.

       During  this selection the widget uses the keymap menuselect.  Any key that is not defined
       in this keymap or that is bound to undefined-key is looked  up  in  the  keymap  currently
       selected.   This  is  used  to  ensure  that the most important keys used during selection
       (namely the cursor keys, return, and TAB) have sensible defaults.  However,  keys  in  the
       menuselect  keymap  can  be  modified  directly  using  the  bindkey  builtin command (see
       zshmodules(1)). For example, to make the return key leave menu selection without accepting
       the match currently selected one could call

              bindkey -M menuselect '^M' send-break

       after loading the zsh/complist module.

THE ZSH/COMPUTIL MODULE

       The  zsh/computil  module  adds  several  builtin  commands  that  are used by some of the
       completion functions in the completion system based on shell functions (see  zshcompsys(1)
       ).   Except  for  compquote  these builtin commands are very specialised and thus not very
       interesting when writing  your  own  completion  functions.   In  summary,  these  builtin
       commands are:

       comparguments
              This  is  used  by  the  _arguments  function  to  do the argument and command line
              parsing.  Like compdescribe it has an option -i to do the  parsing  and  initialize
              some  internal  state and various options to access the state information to decide
              what should be completed.

       compdescribe
              This is used by the _describe function to build the displays for the matches and to
              get the strings to add as matches with their options.  On the first call one of the
              options -i or -I should be supplied as the first  argument.   In  the  first  case,
              display strings without the descriptions will be generated, in the second case, the
              string used to separate the matches from their descriptions must be  given  as  the
              second  argument  and the descriptions (if any) will be shown.  All other arguments
              are like the definition arguments to _describe itself.

              Once compdescribe has been called with either the -i or the -I option,  it  can  be
              repeatedly  called  with  the  -g  option  and  the names of four parameters as its
              arguments.  This will step through the different sets  of  matches  and  store  the
              value of compstate[list] in the first scalar, the options for compadd in the second
              array, the matches in the third array, and the  strings  to  be  displayed  in  the
              completion  listing  in the fourth array.  The arrays may then be directly given to
              compadd to register the matches with the completion code.

       compfiles
              Used by the _path_files function to optimize complex recursive filename  generation
              (globbing).   It  does three things.  With the -p and -P options it builds the glob
              patterns to use, including the paths already handled and  trying  to  optimize  the
              patterns  with  respect  to  the  prefix  and  suffix  from  the line and the match
              specification currently used.  The -i option  does  the  directory  tests  for  the
              ignore-parents style and the -r option tests if a component for some of the matches
              are equal to the string on the line and removes all other matches if that is true.

       compgroups
              Used by the _tags function to implement the internals  of  the  group-order  style.
              This  only takes its arguments as names of completion groups and creates the groups
              for it (all six types: sorted and unsorted, both without removing duplicates,  with
              removing all duplicates and with removing consecutive duplicates).

       compquote [ -p ] names ...
              There  may  be  reasons  to write completion functions that have to add the matches
              using the -Q  option  to  compadd  and  perform  quoting  themselves.   Instead  of
              interpreting  the  first  character  of the all_quotes key of the compstate special
              association and using the q flag for parameter expansions, one can use this builtin
              command.   The arguments are the names of scalar or array parameters and the values
              of these parameters are quoted as needed for the innermost quoting level.   If  the
              -p option is given, quoting is done as if there is some prefix before the values of
              the parameters, so that a leading equal sign will not be quoted.

              The return status is non-zero in case of an error and zero otherwise.

       comptags
       comptry
              These implement the internals of the tags mechanism.

       compvalues
              Like comparguments, but for the _values function.

THE ZSH/CURSES MODULE

       The zsh/curses module makes available one builtin command and various parameters.

   Builtin
       zcurses init
       zcurses end
       zcurses addwin targetwin nlines ncols begin_y begin_x [ parentwin ]
       zcurses delwin targetwin
       zcurses refresh [ targetwin ... ]
       zcurses touch targetwin ...
       zcurses move targetwin new_y new_x
       zcurses clear targetwin [ redraw | eol | bot ]
       zcurses position targetwin array
       zcurses char targetwin character
       zcurses string targetwin string
       zcurses border targetwin border
       zcurses attr targetwin [ [+|-]attribute | fg_col/bg_col ] [...]
       zcurses bg targetwin [ [+|-]attribute | fg_col/bg_col | @char ] [...]
       zcurses scroll targetwin [ on | off | [+|-]lines ]
       zcurses input targetwin [ param [ kparam [ mparam ] ] ]
       zcurses mouse [ delay num | [+|-]motion ]
       zcurses timeout targetwin intval
       zcurses querychar targetwin [ param ]
              Manipulate curses windows.  All  uses  of  this  command  should  be  bracketed  by
              `zcurses  init'  to initialise use of curses, and `zcurses end' to end it; omitting
              `zcurses end' can cause the terminal to be in an unwanted state.

              The subcommand addwin creates a window with nlines lines and  ncols  columns.   Its
              upper  left  corner will be placed at row begin_y and column begin_x of the screen.
              targetwin is a string and refers to the name of a  window  that  is  not  currently
              assigned.   Note  in  particular  the curses convention that vertical values appear
              before horizontal values.

              If addwin is given an existing window as the final  argument,  the  new  window  is
              created  as  a subwindow of parentwin.  This differs from an ordinary new window in
              that the memory of  the  window  contents  is  shared  with  the  parent's  memory.
              Subwindows  must  be  deleted  before  their  parent.  Note that the coordinates of
              subwindows are relative to the screen, not the parent, as with other windows.

              Use the subcommand delwin to delete a window created with addwin.   Note  that  end
              does not implicitly delete windows, and that delwin does not erase the screen image
              of the window.

              The window corresponding to the full visible screen is  called  stdscr;  it  always
              exists after `zcurses init' and cannot be delete with delwin.

              The subcommand refresh will refresh window targetwin; this is necessary to make any
              pending changes (such as characters you have prepared for output with char) visible
              on  the  screen.   refresh  without an argument causes the screen to be cleared and
              redrawn.  If multiple windows are given, the screen is updated once at the end.

              The subcommand touch marks the targetwins listed as  changed.   This  is  necessary
              before  refreshing  windows  if a window that was in front of another window (which
              may be stdscr) is deleted.

              The subcommand move moves the cursor position in targetwin to new coordinates new_y
              and  new_x.  Note that the subcommand string (but not the subcommand char) advances
              the cursor position over the characters added.

              The subcommand clear erases the contents of targetwin.  One (and no more than  one)
              of  three  options  may be specified.  With the option redraw, in addition the next
              refresh of targetwin will cause the screen to be cleared and repainted.   With  the
              option  eol, targetwin is only cleared to the end of the current cursor line.  With
              the option bot, targetwin is cleared to the end of the window,  i.e  everything  to
              the right and below the cursor is cleared.

              The subcommand position writes various positions associated with targetwin into the
              array named array.  These are, in order:
              -      The y and x coordinates of the cursor relative to the top left of targetwin
              -      The y and x coordinates of the top left of targetwin on the screen
              -      The size of targetwin in y and x dimensions.

              Outputting characters and strings are achieved by char and string respectively.

              To draw a border around window targetwin, use border.  Note that the border is  not
              subsequently  handled  specially:   in  other  words, the border is simply a set of
              characters output at the edge of the window.  Hence  it  can  be  overwritten,  can
              scroll off the window, etc.

              The  subcommand attr will set targetwin's attributes or foreground/background color
              pair for any successive character output.  Each attribute given on the line may  be
              prepended  by  a  +  to set or a - to unset that attribute; + is assumed if absent.
              The attributes supported are blink, bold, dim, reverse, standout, and underline.

              Each fg_col/bg_col attribute (to be read as `fg_col on bg_col') sets the foreground
              and  background  color  for  character  output.   The  color  default  is sometimes
              available (in particular if the library is ncurses), specifying the  foreground  or
              background  color  with which the terminal started.  The color pair default/default
              is always available.

              bg overrides the color and other attributes of all characters in the  window.   Its
              usual  use is to set the background initially, but it will overwrite the attributes
              of any characters at the time when it is called.   In  addition  to  the  arguments
              allowed with attr, an argument @char specifies a character to be shown in otherwise
              blank areas of the window.  Owing  to  limitations  of  curses  this  cannot  be  a
              multibyte  character  (use  of  ASCII  characters  only  is  recommended).   As the
              specified set of attributes override the existing  background,  turning  attributes
              off in the arguments is not useful, though this does not cause an error.

              The subcommand scroll can be used with on or off to enabled or disable scrolling of
              a window when the cursor would otherwise move below the window  due  to  typing  or
              output.   It  can  also  be  used with a positive or negative integer to scroll the
              window up or down the given number of lines without  changing  the  current  cursor
              position (which therefore appears to move in the opposite direction relative to the
              window).  In the second case, if scrolling is off it is temporarily  turned  on  to
              allow the window to be scrolled.

              The  subcommand  input  reads a single character from the window without echoing it
              back.  If param is supplied the character is assigned to the parameter param,  else
              it is assigned to the parameter REPLY.

              If  both  param and kparam are supplied, the key is read in `keypad' mode.  In this
              mode special keys such as function keys and arrow keys return the name of  the  key
              in  the  parameter kparam.  The key names are the macros defined in the curses.h or
              ncurses.h with the prefix `KEY_' removed; see also the description of the parameter
              zcurses_keycodes below.  Other keys cause a value to be set in param as before.  On
              a successful return only one of param or kparam contains a  non-empty  string;  the
              other is set to an empty string.

              If  mparam  is  also  supplied, input attempts to handle mouse input.  This is only
              available with the ncurses library; mouse handling can be detected by checking  for
              the exit status of `zcurses mouse' with no arguments.  If a mouse button is clicked
              (or double- or triple-clicked, or pressed or released  with  a  configurable  delay
              from being clicked) then kparam is set to the string MOUSE, and mparam is set to an
              array consisting of the following elements:
              -      An identifier to discriminate different input devices; this is  only  rarely
                     useful.
              -      The  x,  y and z coordinates of the mouse click relative to the full screen,
                     as three elements in that order (i.e. the y coordinate is, unusually,  after
                     the  x  coordinate).   The  z coordinate is only available for a few unusual
                     input devices and is otherwise set to zero.
              -      Any events that occurred as separate items; usually there will be just  one.
                     An   event   consists  of  PRESSED,  RELEASED,  CLICKED,  DOUBLE_CLICKED  or
                     TRIPLE_CLICKED followed immediately (in the same element) by the  number  of
                     the button.
              -      If the shift key was pressed, the string SHIFT.
              -      If the control key was pressed, the string CTRL.
              -      If the alt key was pressed, the string ALT.

              Not  all  mouse  events may be passed through to the terminal window; most terminal
              emulators handle some mouse  events  themselves.   Note  that  the  ncurses  manual
              implies  that  using input both with and without mouse handling may cause the mouse
              cursor to appear and disappear.

              The subcommand mouse can be used to configure the use of the mouse.   There  is  no
              window  argument;  mouse  options  are  global.   `zcurses mouse' with no arguments
              returns status 0 if mouse handling is possible,  else  status  1.   Otherwise,  the
              possible arguments (which may be combined on the same command line) are as follows.
              delay num sets the maximum delay in milliseconds between press and  release  events
              to be considered as a click; the value 0 disables click resolution, and the default
              is one sixth of a second.  motion proceeded by an optional `+' (the default)  or  -
              turns  on  or  off  reporting  of  mouse  motion in addition to clicks, presses and
              releases, which are always reported.  However, it appears reports for mouse  motion
              are not currently implemented.

              The  subcommand  timeout  specifies  a  timeout value for input from targetwin.  If
              intval is negative, `zcurses input' waits indefinitely for a character to be typed;
              this  is  the  default.  If intval is zero, `zcurses input' returns immediately; if
              there is typeahead it is returned, else no input is done and status 1 is  returned.
              If  intval  is positive, `zcurses input' waits intval milliseconds for input and if
              there is none at the end of that period returns status 1.

              The subcommand querychar queries the character at the current cursor position.  The
              return  values  are  stored in the array named param if supplied, else in the array
              reply.  The first value is the character (which may be a multibyte character if the
              system  supports  them);  the  second  is the color pair in the usual fg_col/bg_col
              notation, or 0 if color is not supported.  Any attributes  other  than  color  that
              apply  to  the  character,  as  set  with the subcommand attr, appear as additional
              elements.

   Parameters
       ZCURSES_COLORS
              Readonly integer.  The maximum number of colors the terminal supports.  This  value
              is  initialised  by  the  curses  library and is not available until the first time
              zcurses init is run.

       ZCURSES_COLOR_PAIRS
              Readonly integer.  The maximum number of color  pairs  fg_col/bg_col  that  may  be
              defined in `zcurses attr' commands; note this limit applies to all color pairs that
              have been used whether or not they are currently active.  This value is initialised
              by  the  curses  library  and is not available until the first time zcurses init is
              run.

       zcurses_attrs
              Readonly array.  The attributes supported by zsh/curses; available as soon  as  the
              module is loaded.

       zcurses_colors
              Readonly  array.   The  colors  supported  by  zsh/curses; available as soon as the
              module is loaded.

       zcurses_keycodes
              Readonly array.  The values that may be returned in the second  parameter  supplied
              to  `zcurses  input'  in  the order in which they are defined internally by curses.
              Not all function keys are listed, only F0; curses reserves space for F0 up to F63.

       zcurses_windows
              Readonly array.  The current list of windows,  i.e.  all  windows  that  have  been
              created with `zcurses addwin' and not removed with `zcurses delwin'.

THE ZSH/DATETIME MODULE

       The zsh/datetime module makes available one builtin command:

       strftime [ -s scalar ] format epochtime
       strftime -r [ -q ] [ -s scalar ] format timestring
              Output  the date denoted by epochtime in the format specified.  See strftime(3) for
              details.  The zsh extensions described in the section EXPANSION OF PROMPT SEQUENCES
              in zshmisc(1) are also available.

              -q     Run  quietly;  suppress  printing  of  all  error  messages described below.
                     Errors for invalid epochtime values are always printed.

              -r     With the  option  -r  (reverse),  use  format  to  parse  the  input  string
                     timestring  and  output  the  number of seconds since the epoch at which the
                     time occurred.  The parsing is implemented by the system function  strptime;
                     see  strptime(3).   This means that zsh format extensions are not available,
                     but for reverse lookup they are not required.

                     In most implementations of  strftime  any  timezone  in  the  timestring  is
                     ignored  and  the  local timezone declared by the TZ environment variable is
                     used; other parameters are set to zero if not present.

                     If timestring does not match format the command returns status 1 and  prints
                     an  error  message.   If timestring matches format but not all characters in
                     timestring were used, the conversion  succeeds  but  also  prints  an  error
                     message.

                     If  either  of  the  system  functions  strptime or mktime is not available,
                     status 2 is returned and an error message is printed.

              -s scalar
                     Assign the date string (or epoch time in seconds if -r is given)  to  scalar
                     instead of printing it.

              Note  that  depending  on  the  system's  declared integral time type, strftime may
              produce incorrect results for epoch times greater than 2147483647 which corresponds
              to 2038-01-19 03:14:07 +0000.

       The zsh/datetime module makes available several parameters; all are readonly:

       EPOCHREALTIME
              A  floating  point  value  representing the number of seconds since the epoch.  The
              notional accuracy is to nanoseconds if the clock_gettime call is available  and  to
              microseconds  otherwise,  but  in  practice  the range of double precision floating
              point and shell scheduling latencies may be significant effects.

       EPOCHSECONDS
              An integer value representing the number of seconds since the epoch.

       epochtime
              An array value containing the number of  seconds  since  the  epoch  in  the  first
              element  and the remainder of the time since the epoch in nanoseconds in the second
              element.  To ensure the two elements are consistent the array should be  copied  or
              otherwise  referenced  as  a  single  substitution before the values are used.  The
              following idiom may be used:

                     for secs nsecs in $epochtime; do
                       ...
                     done

THE ZSH/DB/GDBM MODULE

       The zsh/db/gdbm module is used to create  "tied"  associative  arrays  that  interface  to
       database  files.   If  the  GDBM  interface is not available, the builtins defined by this
       module will report an error.  This module is also intended as  a  prototype  for  creating
       additional  database  interfaces, so the ztie builtin may move to a more generic module in
       the future.

       The builtins in this module are:

       ztie -d db/gdbm -f filename [ -r ] arrayname
              Open the GDBM database identified  by  filename  and,  if  successful,  create  the
              associative  array arrayname linked to the file.  To create a local tied array, the
              parameter must first be declared, so commands similar to  the  following  would  be
              executed inside a function scope:

                     local -A sampledb
                     ztie -d db/gdbm -f sample.gdbm sampledb

              The  -r  option opens the database file for reading only, creating a parameter with
              the readonly attribute.  Without this option, using `ztie' on a file for which  the
              user  does  not  have  write  permission is an error.  If writable, the database is
              opened synchronously so fields changed in  arrayname  are  immediately  written  to
              filename.

              Changes  to the file modes filename after it has been opened do not alter the state
              of arrayname, but `typeset -r arrayname' works as expected.

       zuntie [ -u ] arrayname ...
              Close the  GDBM  database  associated  with  each  arrayname  and  then  unset  the
              parameter.   The  -u  option forces an unset of parameters made readonly with `ztie
              -r'.

              This happens automatically if the parameter is explicitly unset or its local  scope
              (function)  ends.   Note  that a readonly parameter may not be explicitly unset, so
              the only way to unset a global parameter created with `ztie -r' is to  use  `zuntie
              -u'.

       The fields of an associative array tied to GDBM are neither cached nor otherwise stored in
       memory, they are read from or written to  the  database  on  each  reference.   Thus,  for
       example,  the  values  in  a  readonly array may be changed by a second writer of the same
       database file.

THE ZSH/DELTOCHAR MODULE

       The zsh/deltochar module makes available two ZLE functions:

       delete-to-char
              Read a character from the keyboard, and delete from the cursor position up  to  and
              including  the  next (or, with repeat count n, the nth) instance of that character.
              Negative repeat counts mean delete backwards.

       zap-to-char
              This behaves like delete-to-char, except that the final occurrence of the character
              itself is not deleted.

THE ZSH/EXAMPLE MODULE

       The zsh/example module makes available one builtin command:

       example [ -flags ] [ args ... ]
              Displays the flags and arguments it is invoked with.

       The purpose of the module is to serve as an example of how to write a module.

THE ZSH/FILES MODULE

       The  zsh/files  module  makes  available  some  common  commands  for file manipulation as
       builtins; these commands are probably not needed for many normal  situations  but  can  be
       useful  in  emergency recovery situations with constrained resources.  The commands do not
       implement all features now required by relevant standards committees.

       For all commands, a variant beginning zf_ is  also  available  and  loaded  automatically.
       Using  the  features  capability  of zmodload will let you load only those names you want.
       Note that it's possible to load only  the  builtins  with  zsh-specific  names  using  the
       following command:

              zmodload -m -F zsh/files b:zf_\*

       The commands loaded by default are:

       chgrp [ -hRs ] group filename ...
              Changes  group  of  files  specified.  This is equivalent to chown with a user-spec
              argument of `:group'.

       chown [ -hRs ] user-spec filename ...
              Changes ownership and group of files specified.

              The user-spec can be in four forms:

              user   change owner to user; do not change group
              user:: change owner to user; do not change group
              user:  change owner to user; change group to user's primary group
              user:group
                     change owner to user; change group to group
              :group do not change owner; change group to group

              In each case, the `:' may instead be a `.'.  The rule is that if  there  is  a  `:'
              then  the  separator is `:', otherwise if there is a `.' then the separator is `.',
              otherwise there is no separator.

              Each of user and group may be either a username (or group name, as appropriate)  or
              a  decimal user ID (group ID).  Interpretation as a name takes precedence, if there
              is an all-numeric username (or group name).

              If the target is a symbolic link, the -h option causes chown to set  the  ownership
              of the link instead of its target.

              The  -R  option  causes chown to recursively descend into directories, changing the
              ownership of all files in  the  directory  after  changing  the  ownership  of  the
              directory itself.

              The  -s  option  is  a  zsh  extension to chown functionality.  It enables paranoid
              behaviour, intended to avoid security problems involving a chown being tricked into
              affecting  files  other  than the ones intended.  It will refuse to follow symbolic
              links, so that (for example) ``chown  luser  /tmp/foo/passwd''  can't  accidentally
              chown  /etc/passwd  if  /tmp/foo  happens to be a link to /etc.  It will also check
              where it is after leaving  directories,  so  that  a  recursive  chown  of  a  deep
              directory  tree  can't  end up recursively chowning /usr as a result of directories
              being moved up the tree.

       ln [ -dfhins ] filename dest
       ln [ -dfhins ] filename ... dir
              Creates hard (or, with -s, symbolic) links.   In  the  first  form,  the  specified
              destination  is  created, as a link to the specified filename.  In the second form,
              each of the filenames is taken in turn, and linked to a pathname in  the  specified
              directory that has the same last pathname component.

              Normally,  ln will not attempt to create hard links to directories.  This check can
              be overridden using the -d option.  Typically  only  the  super-user  can  actually
              succeed  in  creating  hard  links to directories.  This does not apply to symbolic
              links in any case.

              By default, existing files cannot be replaced by links.  The -i option  causes  the
              user  to  be queried about replacing existing files.  The -f option causes existing
              files to be silently deleted, without querying.  -f takes precedence.

              The -h and -n options are identical and both exist for  compatibility;  either  one
              indicates  that  if  the  target  is  a symlink then it should not be dereferenced.
              Typically this is used in combination with -sf so that if an existing  link  points
              to  a  directory  then  it will be removed, instead of followed.  If this option is
              used with multiple filenames and the target  is  a  symbolic  link  pointing  to  a
              directory then the result is an error.

       mkdir [ -p ] [ -m mode ] dir ...
              Creates directories.  With the -p option, non-existing parent directories are first
              created if necessary, and there will be  no  complaint  if  the  directory  already
              exists.   The -m option can be used to specify (in octal) a set of file permissions
              for the created directories, otherwise mode 777 modified by the current umask  (see
              umask(2)) is used.

       mv [ -fi ] filename dest
       mv [ -fi ] filename ... dir
              Moves  files.   In the first form, the specified filename is moved to the specified
              destination.  In the second form, each of the filenames is taken in turn, and moved
              to a pathname in the specified directory that has the same last pathname component.

              By default, the user will be queried before replacing any file that the user cannot
              write to, but writable files will be silently removed.  The -i  option  causes  the
              user  to  be  queried about replacing any existing files.  The -f option causes any
              existing files to be silently deleted, without querying.  -f takes precedence.

              Note that this mv will not move files across devices.  Historical versions  of  mv,
              when  actual  renaming  is  impossible, fall back on copying and removing files; if
              this behaviour is desired, use cp and rm manually.  This may  change  in  a  future
              version.

       rm [ -dfirs ] filename ...
              Removes files and directories specified.

              Normally,  rm  will  not  remove  directories  (except with the -r option).  The -d
              option causes rm to try removing directories with unlink (see unlink(2)), the  same
              method  used  for  files.   Typically  only  the super-user can actually succeed in
              unlinking directories in this way.  -d takes precedence over -r.

              By default, the user will be queried before removing any file that the user  cannot
              write  to,  but  writable files will be silently removed.  The -i option causes the
              user to be queried about removing any files.  The -f  option  causes  files  to  be
              silently deleted, without querying, and suppresses all error indications.  -f takes
              precedence.

              The -r option causes rm to recursively descend into directories, deleting all files
              in  the  directory  before  removing  the directory with the rmdir system call (see
              rmdir(2)).

              The -s option is  a  zsh  extension  to  rm  functionality.   It  enables  paranoid
              behaviour, intended to avoid common security problems involving a root-run rm being
              tricked into removing files other than the ones intended.  It will refuse to follow
              symbolic  links,  so  that  (for example) ``rm /tmp/foo/passwd'' can't accidentally
              remove /etc/passwd if /tmp/foo happens to be a link to /etc.  It  will  also  check
              where  it  is  after  leaving  directories,  so  that a recursive removal of a deep
              directory tree can't end up recursively removing /usr as a  result  of  directories
              being moved up the tree.

       rmdir dir ...
              Removes empty directories specified.

       sync   Calls  the  system call of the same name (see sync(2)), which flushes dirty buffers
              to disk.  It might return before the I/O has actually been completed.

THE ZSH/LANGINFO MODULE

       The zsh/langinfo module makes available one parameter:

       langinfo
              An associative array that maps langinfo elements to their values.

              Your implementation may support a number of the following keys:

              CODESET, D_T_FMT, D_FMT, T_FMT,  RADIXCHAR,  THOUSEP,  YESEXPR,  NOEXPR,  CRNCYSTR,
              ABDAY_{1..7},  DAY_{1..7},  ABMON_{1..12}, MON_{1..12}, T_FMT_AMPM, AM_STR, PM_STR,
              ERA, ERA_D_FMT, ERA_D_T_FMT, ERA_T_FMT, ALT_DIGITS

THE ZSH/MAPFILE MODULE

       The zsh/mapfile module provides one special associative array parameter of the same name.

       mapfile
              This associative array takes as keys the names of files; the resulting value is the
              content  of  the  file.   The value is treated identically to any other text coming
              from a parameter.  The value may also be assigned to, in which  case  the  file  in
              question  is  written  (whether or not it originally existed); or an element may be
              unset,  which  will  delete  the   file   in   question.    For   example,   `vared
              mapfile[myfile]' works as expected, editing the file `myfile'.

              When  the  array  is  accessed  as  a whole, the keys are the names of files in the
              current directory, and the values are empty (to save a huge  overhead  in  memory).
              Thus  ${(k)mapfile}  has  the  same  affect  as the glob operator *(D), since files
              beginning with a dot are not special.  Care must be taken with expressions such  as
              rm ${(k)mapfile}, which will delete every file in the current directory without the
              usual `rm *' test.

              The parameter mapfile may be made read-only; in that case, files referenced may not
              be written or deleted.

              A file may conveniently be read into an array as one line per element with the form
              `array=("${(f@)mapfile[filename]}")'.  The double quotes and the `@' are  necessary
              to  prevent  empty  lines  from  being  removed.  Note that if the file ends with a
              newline, the shell will split on the final newline, generating an additional  empty
              field;         this         can         be        suppressed        by        using
              `array=("${(f@)${mapfile[filename]%$'\n'}}")'.

   Limitations
       Although reading and writing of  the  file  in  question  is  efficiently  handled,  zsh's
       internal  memory  management  may be arbitrarily baroque; however, mapfile is usually very
       much more efficient than anything involving a loop.  Note in  particular  that  the  whole
       contents  of  the  file  will  always  reside physically in memory when accessed (possibly
       multiple times, due to standard parameter substitution operations).  In  particular,  this
       means  handling of sufficiently long files (greater than the machine's swap space, or than
       the range of the pointer type) will be incorrect.

       No errors are printed or flagged for non-existent, unreadable, or unwritable files, as the
       parameter mechanism is too low in the shell execution hierarchy to make this convenient.

       It  is  unfortunate  that the mechanism for loading modules does not yet allow the user to
       specify the name of the shell parameter to be given the special behaviour.

THE ZSH/MATHFUNC MODULE

       The zsh/mathfunc module provides standard mathematical functions for use  when  evaluating
       mathematical  formulae.   The  syntax  agrees  with  normal C and FORTRAN conventions, for
       example,

              (( f = sin(0.3) ))

       assigns the sine of 0.3 to the parameter f.

       Most functions take floating point arguments and return a floating point value.   However,
       any  necessary  conversions from or to integer type will be performed automatically by the
       shell.  Apart from atan with a second argument and the abs, int and float  functions,  all
       functions behave as noted in the manual page for the corresponding C function, except that
       any arguments out of range for the function in question will be detected by the shell  and
       an error reported.

       The  following  functions take a single floating point argument: acos, acosh, asin, asinh,
       atan, atanh, cbrt, ceil, cos, cosh, erf, erfc, exp, expm1, fabs,  floor,  gamma,  j0,  j1,
       lgamma,  log,  log10,  log1p, logb, sin, sinh, sqrt, tan, tanh, y0, y1.  The atan function
       can optionally take a second argument, in which case it behaves like the C function atan2.
       The ilogb function takes a single floating point argument, but returns an integer.

       The  function  signgam takes no arguments, and returns an integer, which is the C variable
       of the same name, as described in  gamma(3).   Note  that  it  is  therefore  only  useful
       immediately after a call to gamma or lgamma.  Note also that `signgam()' and `signgam' are
       distinct expressions.

       The following  functions  take  two  floating  point  arguments:  copysign,  fmod,  hypot,
       nextafter.

       The following take an integer first argument and a floating point second argument: jn, yn.

       The  following take a floating point first argument and an integer second argument: ldexp,
       scalb.

       The function abs does not convert the type of its single argument; it returns the absolute
       value  of  either  a  floating  point  number  or an integer.  The functions float and int
       convert  their  arguments  into  a  floating  point  or  integer  value  (by   truncation)
       respectively.

       Note that the C pow function is available in ordinary math evaluation as the `**' operator
       and is not provided here.

       The function rand48 is available if your system's mathematical library  has  the  function
       erand48(3).  It returns a pseudo-random floating point number between 0 and 1.  It takes a
       single string optional argument.

       If the argument is not present, the random number seed is initialised by  three  calls  to
       the rand(3) function --- this produces the same random numbers as the next three values of
       $RANDOM.

       If the argument is present, it gives the name of a  scalar  parameter  where  the  current
       random  number  seed  will  be stored.  On the first call, the value must contain at least
       twelve hexadecimal digits (the remainder of the string is ignored), or the  seed  will  be
       initialised in the same manner as for a call to rand48 with no argument.  Subsequent calls
       to rand48(param) will then maintain the seed in the parameter param as a string of  twelve
       hexadecimal  digits,  with  no  base signifier.  The random number sequences for different
       parameters are completely independent, and are also independent from that used by calls to
       rand48 with no argument.

       For example, consider

              print $(( rand48(seed) ))
              print $(( rand48() ))
              print $(( rand48(seed) ))

       Assuming  $seed  does  not exist, it will be initialised by the first call.  In the second
       call, the default seed is initialised; note, however, that because of  the  properties  of
       rand()  there  is a correlation between the seeds used for the two initialisations, so for
       more secure uses, you should generate your own 12-byte seed.  The third  call  returns  to
       the  same sequence of random numbers used in the first call, unaffected by the intervening
       rand48().

THE ZSH/NEWUSER MODULE

       The zsh/newuser module is loaded at boot if it is available, the RCS option  is  set,  and
       the  PRIVILEGED  option  is  not  set  (all  three are true by default).  This takes place
       immediately after commands in the global zshenv file (typically /etc/zshenv), if any, have
       been  executed.   If  the module is not available it is silently ignored by the shell; the
       module may safely be removed from $MODULE_PATH by the administrator if it is not required.

       On loading, the module tests if any of the start-up files .zshenv,  .zprofile,  .zshrc  or
       .zlogin  exist  in  the directory given by the environment variable ZDOTDIR, or the user's
       home directory if that is not set.  The  test  is  not  performed  and  the  module  halts
       processing  if  the  shell  was  in an emulation mode (i.e. had been invoked as some other
       shell than zsh).

       If none of the start-up files were found, the module then looks for the file newuser first
       in a sitewide directory, usually the parent directory of the site-functions directory, and
       if that is not found the module searches in  a  version-specific  directory,  usually  the
       parent   of   the  functions  directory  containing  version-specific  functions.   (These
       directories can be configured when zsh is built using the --enable-site-scriptdir=dir  and
       --enable-scriptdir=dir flags to configure, respectively; the defaults are prefix/share/zsh
       and prefix/share/zsh/$ZSH_VERSION where the default prefix is /usr/local.)

       If the file newuser is found, it is then sourced in the same manner as  a  start-up  file.
       The  file  is expected to contain code to install start-up files for the user, however any
       valid shell code will be executed.

       The zsh/newuser module is then unconditionally unloaded.

       Note that it is possible to achieve exactly the same effect as the zsh/newuser  module  by
       adding  code  to  /etc/zshenv.   The  module  exists  simply  to  allow  the shell to make
       arrangements for new users without the need for intervention by  package  maintainers  and
       system administrators.

       The  script supplied with the module invokes the shell function zsh-newuser-install.  This
       may be invoked directly by the user even if the zsh/newuser  module  is  disabled.   Note,
       however,  that  if  the module is not installed the function will not be installed either.
       The function is documented in the section User Configuration Functions in zshcontrib(1).

THE ZSH/PARAMETER MODULE

       The zsh/parameter module gives access to some of the internal  hash  tables  used  by  the
       shell by defining some special parameters.

       options
              The  keys  for  this associative array are the names of the options that can be set
              and unset using the setopt and unsetopt builtins. The value of each key  is  either
              the  string  on  if the option is currently set, or the string off if the option is
              unset.  Setting a key to one of these strings is  like  setting  or  unsetting  the
              option, respectively. Unsetting a key in this array is like setting it to the value
              off.

       commands
              This array gives access to the command hash  table.  The  keys  are  the  names  of
              external commands, the values are the pathnames of the files that would be executed
              when the command would be invoked. Setting a key in this array defines a new  entry
              in  this  table  in  the  same  way as with the hash builtin. Unsetting a key as in
              `unset "commands[foo]"' removes the entry for the given key from the  command  hash
              table.

       functions
              This  associative  array  maps  names  of  enabled  functions to their definitions.
              Setting a key in it is like defining a function with the name given by the key  and
              the  body  given  by  the  value.  Unsetting  a  key removes the definition for the
              function named by the key.

       dis_functions
              Like functions but for disabled functions.

       builtins
              This associative array gives  information  about  the  builtin  commands  currently
              enabled.  The  keys are the names of the builtin commands and the values are either
              `undefined' for builtin commands that will automatically be loaded from a module if
              invoked or `defined' for builtin commands that are already loaded.

       dis_builtins
              Like builtins but for disabled builtin commands.

       reswords
              This array contains the enabled reserved words.

       dis_reswords
              Like reswords but for disabled reserved words.

       patchars
              This array contains the enabled pattern characters.

       dis_patchars
              Like patchars but for disabled pattern characters.

       aliases
              This maps the names of the regular aliases currently enabled to their expansions.

       dis_aliases
              Like aliases but for disabled regular aliases.

       galiases
              Like aliases, but for global aliases.

       dis_galiases
              Like galiases but for disabled global aliases.

       saliases
              Like raliases, but for suffix aliases.

       dis_saliases
              Like saliases but for disabled suffix aliases.

       parameters
              The  keys  in  this  associative  array  are  the names of the parameters currently
              defined. The values are strings describing the type of the parameter, in  the  same
              format used by the t parameter flag, see zshexpn(1) .  Setting or unsetting keys in
              this array is not possible.

       modules
              An associative array giving information about modules. The keys are  the  names  of
              the  modules  loaded, registered to be autoloaded, or aliased. The value says which
              state the named module is in and is one of the strings `loaded',  `autoloaded',  or
              `alias:name', where name is the name the module is aliased to.

              Setting or unsetting keys in this array is not possible.

       dirstack
              A normal array holding the elements of the directory stack. Note that the output of
              the  dirs  builtin  command  includes  one  more  directory,  the  current  working
              directory.

       history
              This associative array maps history event numbers to the full history lines.

       historywords
              A special array containing the words stored in the history.

       jobdirs
              This  associative  array maps job numbers to the directories from which the job was
              started (which may not be the current directory of the job).

              The keys of the associative arrays are usually valid job numbers, and these are the
              values  output with, for example, ${(k)jobdirs}.  Non-numeric job references may be
              used when looking up a value; for example, ${jobdirs[%+]}  refers  to  the  current
              job.

       jobtexts
              This associative array maps job numbers to the texts of the command lines that were
              used to start the jobs.

              Handling of the keys of the associative array is as described for jobdirs above.

       jobstates
              This associative array gives information about the states  of  the  jobs  currently
              known.  The  keys  are  the  job  numbers  and  the  values are strings of the form
              `job-state:mark:pid=state...'. The job-state gives  the  state  the  whole  job  is
              currently  in,  one  of  `running', `suspended', or `done'. The mark is `+' for the
              current job, `-' for the previous job and empty otherwise. This is followed by  one
              `:pid=state' for every process in the job. The pids are, of course, the process IDs
              and the state describes the state of that process.

              Handling of the keys of the associative array is as described for jobdirs above.

       nameddirs
              This associative array maps the names of named directories to  the  pathnames  they
              stand for.

       userdirs
              This associative array maps user names to the pathnames of their home directories.

       usergroups
              This  associative  array maps names of system groups of which the current user is a
              member to the corresponding group identifiers.  The contents are the  same  as  the
              groups output by the id command.

       funcfiletrace
              This  array contains the absolute line numbers and corresponding file names for the
              point where the current function, sourced file, or (if  EVAL_LINENO  is  set)  eval
              command  was  called.   The  array  is  of  the  same length as funcsourcetrace and
              functrace, but differs from funcsourcetrace in that the line and file are the point
              of call, not the point of definition, and differs from functrace in that all values
              are absolute line numbers in  files,  rather  than  relative  to  the  start  of  a
              function, if any.

       funcsourcetrace
              This  array  contains  the  file  names  and  line  numbers of the points where the
              functions, sourced files, and (if EVAL_LINENO is set) eval commands currently being
              executed  were  defined.   The line number is the line where the `function name' or
              `name ()' started.  In the case of an  autoloaded  function   the  line  number  is
              reported  as  zero.   The format of each element is filename:lineno.  For functions
              autoloaded from a file in native zsh format, where only the body  of  the  function
              occurs  in  the  file,  or  for  files that have been executed by the source or `.'
              builtins, the trace information is shown as filename:0, since the  entire  file  is
              the definition.

              Most  users  will  be  interested  in  the  information  in the funcfiletrace array
              instead.

       funcstack
              This array contains the names of the functions, sourced files, and (if  EVAL_LINENO
              is  set)  eval commands. currently being executed. The first element is the name of
              the function using the parameter.

              The standard shell array zsh_eval_context can be used  to  determine  the  type  of
              shell  construct  being  executed  at  each  depth:  note,  however, that is in the
              opposite order, with the most recent item  last,  and  it  is  more  detailed,  for
              example  including an entry for toplevel, the main shell code being executed either
              interactively or from a script, which is not present in $funcstack.

       functrace
              This array contains the names and line numbers of the callers corresponding to  the
              functions  currently  being  executed.   The format of each element is name:lineno.
              Callers are also shown for sourced files; the caller is the point where the  source
              or `.' command was executed.

THE ZSH/PCRE MODULE

       The zsh/pcre module makes some commands available as builtins:

       pcre_compile [ -aimxs ] PCRE
              Compiles a perl-compatible regular expression.

              Option  -a  will  force  the  pattern  to  be  anchored.   Option -i will compile a
              case-insensitive pattern.  Option -m will compile a multi-line pattern; that is,  ^
              and  $  will match newlines within the pattern.  Option -x will compile an extended
              pattern, wherein whitespace and # comments are ignored.  Option -s  makes  the  dot
              metacharacter match all characters, including those that indicate newline.

       pcre_study
              Studies the previously-compiled PCRE which may result in faster matching.

       pcre_match [ -v var ] [ -a arr ] [ -n offset ] [ -b ] string
              Returns successfully if string matches the previously-compiled PCRE.

              Upon  successful  match,  if the expression captures substrings within parentheses,
              pcre_match will set the array match to those substrings, unless the  -a  option  is
              given, in which case it will set the array arr.  Similarly, the variable MATCH will
              be set to the entire matched portion of the string, unless the -v option is  given,
              in  which  case the variable var will be set.  No variables are altered if there is
              no successful match.  A -n option starts searching for a match from the byte offset
              position  in  string.  If the -b option is given, the variable ZPCRE_OP will be set
              to an offset pair string, representing the byte  offset  positions  of  the  entire
              matched  portion  within  the  string.   For  example,  a  ZPCRE_OP  set to "32 45"
              indicates that the matched portion began on byte offset 32 and ended on byte offset
              44.   Here,  byte  offset  position  45  is the position directly after the matched
              portion.  Keep in mind that the byte position isn't necessarily  the  same  as  the
              character  position  when  UTF-8  characters  are involved.  Consequently, the byte
              offset positions are only to be  relied  on  in  the  context  of  using  them  for
              subsequent  searches  on  string, using an offset position as an argument to the -n
              option.  This is mostly used to implement the "find  all  non-overlapping  matches"
              functionality.

              A simple example of "find all non-overlapping matches":

                     string="The following zip codes: 78884 90210 99513"
                     pcre_compile -m "\d{5}"
                     accum=()
                     pcre_match -b -- $string
                     while [[ $? -eq 0 ]] do
                         b=($=ZPCRE_OP)
                         accum+=$MATCH
                         pcre_match -b -n $b[2] -- $string
                     done
                     print -l $accum

       The zsh/pcre module makes available the following test condition:

       expr -pcre-match pcre
              Matches a string against a perl-compatible regular expression.

              For example,

                     [[ "$text" -pcre-match ^d+$ ]] &&
                     print text variable contains only "d's".

              If  the  REMATCH_PCRE  option is set, the =~ operator is equivalent to -pcre-match,
              and the NO_CASE_MATCH option may be used.  Note that NO_CASE_MATCH never applies to
              the pcre_match builtin, instead use the -i switch of pcre_compile.

THE ZSH/REGEX MODULE

       The zsh/regex module makes available the following test condition:

       expr -regex-match regex
              Matches a string against a POSIX extended regular expression.  On successful match,
              matched portion of the string will normally be placed in the  MATCH  variable.   If
              there are any capturing parentheses within the regex, then the match array variable
              will contain those.  If the match is not successful, then the variables will not be
              altered.

              For example,

                     [[ alphabetical -regex-match ^a([^a]+)a([^a]+)a ]] &&
                     print -l $MATCH X $match

              If the option REMATCH_PCRE is not set, then the =~ operator will automatically load
              this module as needed and will invoke the -regex-match operator.

              If BASH_REMATCH is set, then the array BASH_REMATCH will be set  instead  of  MATCH
              and match.

THE ZSH/SCHED MODULE

       The zsh/sched module makes available one builtin command and one parameter.

       sched [-o] [+]hh:mm[:ss] command ...
       sched [-o] [+]seconds command ...
       sched [ -item ]
              Make  an  entry  in  the  scheduled  list  of commands to execute.  The time may be
              specified in either absolute or relative time, and either  as  hours,  minutes  and
              (optionally) seconds separated by a colon, or seconds alone.  An absolute number of
              seconds indicates the time since the epoch (1970/01/01 00:00); this  is  useful  in
              combination  with  the  features  in  the zsh/datetime module, see the zsh/datetime
              module entry in zshmodules(1).

              With no arguments, prints the list of scheduled commands.  If the scheduled command
              has the -o flag set, this is shown at the start of the command.

              With  the argument `-item', removes the given item from the list.  The numbering of
              the list is continuous and entries are in time order, so the numbering  can  change
              when entries are added or deleted.

              Commands are executed either immediately before a prompt, or while the shell's line
              editor is waiting for input.  In the latter case it is useful to be able to produce
              output that does not interfere with the line being edited.  Providing the option -o
              causes the shell to  clear  the  command  line  before  the  event  and  redraw  it
              afterwards.   This  should  be  used with any scheduled event that produces visible
              output to the terminal; it is not needed, for example, with output that  updates  a
              terminal emulator's title bar.

              The  sched builtin is not made available by default when the shell starts in a mode
              emulating another shell.  It can be made available with the  command  `zmodload  -F
              zsh/sched b:sched'.

       zsh_scheduled_events
              A  readonly  array corresponding to the events scheduled by the sched builtin.  The
              indices of the array correspond to the numbers shown when  sched  is  run  with  no
              arguments (provided that the KSH_ARRAYS option is not set).  The value of the array
              consists of the scheduled time in seconds since the epoch  (see  the  section  `The
              zsh/datetime  Module'  for  facilities for using this number), followed by a colon,
              followed by any options (which  may  be  empty  but  will  be  preceded  by  a  `-'
              otherwise), followed by a colon, followed by the command to be executed.

              The  sched builtin should be used for manipulating the events.  Note that this will
              have an immediate effect on the contents of the array, so that indices  may  become
              invalid.

THE ZSH/NET/SOCKET MODULE

       The zsh/net/socket module makes available one builtin command:

       zsocket [ -altv ] [ -d fd ] [ args ]
              zsocket  is  implemented  as  a  builtin  to  allow  full use of shell command line
              editing, file I/O, and job control mechanisms.

   Outbound Connections
       zsocket [ -v ] [ -d fd ] filename
              Open a new Unix domain connection to filename.  The shell parameter REPLY  will  be
              set to the file descriptor associated with that connection.  Currently, only stream
              connections are supported.

              If -d is specified, its argument will be taken as the target  file  descriptor  for
              the connection.

              In order to elicit more verbose output, use -v.

   Inbound Connections
       zsocket -l [ -v ] [ -d fd ] filename
              zsocket  -l  will  open  a socket listening on filename.  The shell parameter REPLY
              will be set to the file descriptor associated with that listener.

              If -d is specified, its argument will be taken as the target  file  descriptor  for
              the connection.

              In order to elicit more verbose output, use -v.

       zsocket -a [ -tv ] [ -d targetfd ] listenfd
              zsocket  -a  will  accept  an  incoming  connection  to  the socket associated with
              listenfd.  The shell parameter REPLY will be set to the file descriptor  associated
              with the inbound connection.

              If  -d  is  specified, its argument will be taken as the target file descriptor for
              the connection.

              If -t is specified, zsocket will return  if  no  incoming  connection  is  pending.
              Otherwise it will wait for one.

              In order to elicit more verbose output, use -v.

THE ZSH/STAT MODULE

       The zsh/stat module makes available one builtin command under two possible names:

       zstat [ -gnNolLtTrs ] [ -f fd ] [ -H hash ] [ -A array ] [ -F fmt ]
             [ +element ] [ file ... ]
       stat ...
              The  command  acts  as a front end to the stat system call (see stat(2)).  The same
              command is provided with two names; as the name stat is often used by  an  external
              command  it  is  recommended that only the zstat form of the command is used.  This
              can be arranged by loading the  module  with  the  command  `zmodload  -F  zsh/stat
              b:zstat'.

              If  the  stat call fails, the appropriate system error message printed and status 1
              is returned.  The fields of struct stat give information about the  files  provided
              as arguments to the command.  In addition to those available from the stat call, an
              extra element `link' is provided.  These elements are:

              device The number of the device on which the file resides.

              inode  The unique number of the file on this device (`inode' number).

              mode   The mode of the file; that is, the file's type and access permissions.  With
                     the  -s option, this will be returned as a string corresponding to the first
                     column in the display of the ls -l command.

              nlink  The number of hard links to the file.

              uid    The user ID of the owner of the file.  With the -s option, this is displayed
                     as a user name.

              gid    The  group ID of the file.  With the -s option, this is displayed as a group
                     name.

              rdev   The raw device number.  This is only useful for special devices.

              size   The size of the file in bytes.

              atime
              mtime
              ctime  The  last  access,  modification  and  inode  change  times  of  the   file,
                     respectively,  as  the  number of seconds since midnight GMT on 1st January,
                     1970.  With the -s option, these are printed as strings for the  local  time
                     zone;  the  format can be altered with the -F option, and with the -g option
                     the times are in GMT.

              blksize
                     The number of bytes in one allocation block on the device on which the  file
                     resides.

              block  The number of disk blocks used by the file.

              link   If the file is a link and the -L option is in effect, this contains the name
                     of the file linked to, otherwise it is empty.  Note that if this element  is
                     selected (``zstat +link'') then the -L option is automatically used.

              A particular element may be selected by including its name preceded by a `+' in the
              option list; only one element is allowed.  The element  may  be  shortened  to  any
              unique  set  of  leading characters.  Otherwise, all elements will be shown for all
              files.

              Options:

              -A array
                     Instead of displaying the results on standard  output,  assign  them  to  an
                     array, one struct stat element per array element for each file in order.  In
                     this case neither the name of the element nor the name of the files  appears
                     in  array  unless  the  -t or -n options were given, respectively.  If -t is
                     given, the element name  appears  as  a  prefix  to  the  appropriate  array
                     element;  if  -n is given, the file name appears as a separate array element
                     preceding all the others.  Other formatting options are respected.

              -H hash
                     Similar to -A, but instead assign the values to  hash.   The  keys  are  the
                     elements  listed  above.   If the -n option is provided then the name of the
                     file is included in the hash with key name.

              -f fd  Use the file on file descriptor fd instead of named files; no list  of  file
                     names is allowed in this case.

              -F fmt Supplies  a strftime (see strftime(3)) string for the formatting of the time
                     elements.  The -s option is implied.

              -g     Show the time elements in the GMT time zone.  The -s option is implied.

              -l     List the names of the type elements (to  standard  output  or  an  array  as
                     appropriate) and return immediately; options other than -A and arguments are
                     ignored.

              -L     Perform an lstat (see lstat(2)) rather than a stat  system  call.   In  this
                     case,  if  the file is a link, information about the link itself rather than
                     the target file is returned.  This option  is  required  to  make  the  link
                     element useful.  It's important to note that this is the exact opposite from
                     ls(1), etc.

              -n     Always show the names of files.  Usually these are only shown when output is
                     to standard output and there is more than one file in the list.

              -N     Never show the names of files.

              -o     If  a  raw  file mode is printed, show it in octal, which is more useful for
                     human consumption than the default of  decimal.   A  leading  zero  will  be
                     printed  in  this  case.   Note  that  this does not affect whether a raw or
                     formatted file mode is shown, which is controlled by the -r and -s  options,
                     nor whether a mode is shown at all.

              -r     Print  raw  data (the default format) alongside string data (the -s format);
                     the string data appears in parentheses after the raw data.

              -s     Print mode, uid, gid and the three  time  elements  as  strings  instead  of
                     numbers.  In each case the format is like that of ls -l.

              -t     Always  show  the type names for the elements of struct stat.  Usually these
                     are only shown when output is to standard output and no  individual  element
                     has been selected.

              -T     Never show the type names of the struct stat elements.

THE ZSH/SYSTEM MODULE

       The zsh/system module makes available various builtin commands and parameters.

   Builtins
       syserror [ -e errvar ] [ -p prefix ] [ errno | errname ]
              This  command  prints  out  the error message associated with errno, a system error
              number, followed by a newline to standard error.

              Instead of the error number, a name errname, for example ENOENT, may be used.   The
              set of names is the same as the contents of the array errnos, see below.

              If the string prefix is given, it is printed in front of the error message, with no
              intervening space.

              If errvar is supplied, the entire message, without a newline, is  assigned  to  the
              parameter names errvar and nothing is output.

              A  return  status  of 0 indicates the message was successfully printed (although it
              may not be useful if the error number was out of  the  system's  range),  a  return
              status  of  1  indicates  an  error  in  the  parameters,  and a return status of 2
              indicates the error name was not recognised (no message is printed for this).

       sysopen [ -arw ] [ -m permissions ] [ -o options ]
               -u fd file
              This command opens a file. The -r, -w and -a flags indicate whether the file should
              be  opened  for  reading, writing and appending, respectively. The -m option allows
              the initial permissions to use when creating a file to be specified in octal  form.
              The file descriptor is specified with -u. Either an explicit file descriptor in the
              range 0 to 9 can be specified or a variable name can be given  to  which  the  file
              descriptor number will be assigned.

              The  -o  option  allows  various  system  specific  options  to  be  specified as a
              comma-separated list. The following is a  list  of  possible  options.  Note  that,
              depending on the system, some may not be available.
              cloexec
                     mark file to be closed when other programs are executed

              create
              creat  create file if it does not exist

              excl   create file, error if it already exists

              noatime
                     suppress updating of the file atime

              nofollow
                     fail if file is a symbolic link

              sync   request that writes wait until data has been physically written

              truncate
              trunc  truncate file to size 0

              To close the file, use one of the following:

                     exec {fd}<&-
                     exec {fd}>&-

       sysread [ -c countvar ] [ -i infd ] [ -o outfd ]
               [ -s bufsize ] [ -t timeout ] [ param ]
              Perform  a  single  system  read  from file descriptor infd, or zero if that is not
              given.  The result of the read is stored in param or REPLY if that  is  not  given.
              If  countvar  is given, the number of bytes read is assigned to the parameter named
              by countvar.

              The maximum number of bytes read is bufsize or 8192 if that is not  given,  however
              the command returns as soon as any number of bytes was successfully read.

              If  timeout  is given, it specifies a timeout in seconds, which may be zero to poll
              the file descriptor.  This is  handled  by  the  poll  system  call  if  available,
              otherwise the select system call if available.

              If  outfd is given, an attempt is made to write all the bytes just read to the file
              descriptor outfd.  If this fails, because of a system error  other  than  EINTR  or
              because  of  an  internal  zsh  error  during  an interrupt, the bytes read but not
              written are stored in the parameter named by param if supplied (no default is  used
              in  this  case),  and  the  number  of  bytes read but not written is stored in the
              parameter named by countvar if that is supplied.  If it  was  successful,  countvar
              contains the full number of bytes transferred, as usual, and param is not set.

              The  error  EINTR  (interrupted  system  call)  is handled internally so that shell
              interrupts are transparent to the caller.  Any other error causes a return.

              The possible return statuses are
              0      At least one byte  of  data  was  successfully  read  and,  if  appropriate,
                     written.

              1      There was an error in the parameters to the command.  This is the only error
                     for which a message is printed to standard error.

              2      There was an error on the read, or on polling the input file descriptor  for
                     a timeout.  The parameter ERRNO gives the error.

              3      Data  were  successfully read, but there was an error writing them to outfd.
                     The parameter ERRNO gives the error.

              4      The attempt to read timed out.  Note this does not set ERRNO as this is  not
                     a system error.

              5      No  system error occurred, but zero bytes were read.  This usually indicates
                     end of file.  The parameters are set according to the usual rules; no  write
                     to outfd is attempted.

       sysseek [ -u fd ] [ -w start|end|current ] offset
              The  current  file  position  at  which  future reads and writes will take place is
              adjusted to  the  specified  byte  offset.  The  offset  is  evaluated  as  a  math
              expression.  The  -u  option allows the file descriptor to be specified. By default
              the offset is specified relative to the start or the file but, with the -w  option,
              it  is  possible  to  specify  that  the  offset  should be relative to the current
              position or the end of the file.

       syswrite [ -c countvar ] [ -o outfd ] data
              The data (a single string of bytes) are written to the file descriptor outfd, or  1
              if  that  is not given, using the write system call.  Multiple write operations may
              be used if the first does not write all the data.

              If countvar is given, the number of byte written is stored in the  parameter  named
              by countvar; this may not be the full length of data if an error occurred.

              The  error  EINTR  (interrupted  system  call)  is  handled internally by retrying;
              otherwise an error causes  the  command  to  return.   For  example,  if  the  file
              descriptor  is  set  to  non-blocking  output,  an  error  EAGAIN (on some systems,
              EWOULDBLOCK) may result in the command returning early.

              The return status may be 0 for success, 1 for an error in  the  parameters  to  the
              command,  or  2  for an error on the write; no error message is printed in the last
              case, but the parameter ERRNO will reflect the error that occurred.

       zsystem flock [ -t timeout ] [ -f var ] [-er] file
       zsystem flock -u fd_expr
              The builtin zsystem's subcommand flock performs  advisory  file  locking  (via  the
              fcntl(2)  system  call)  over  the entire contents of the given file.  This form of
              locking requires the processes accessing the file to cooperate;  its  most  obvious
              use is between two instances of the shell itself.

              In  the first form the named file, which must already exist, is locked by opening a
              file descriptor to the file and applying a lock to the file descriptor.   The  lock
              terminates  when  the  shell  process  that created the lock exits; it is therefore
              often convenient  to  create  file  locks  within  subshells,  since  the  lock  is
              automatically  released  when the subshell exits.  Status 0 is returned if the lock
              succeeds, else status 1.

              In the second form the file descriptor given by the arithmetic  expression  fd_expr
              is  closed,  releasing a lock.  The file descriptor can be queried by using the `-f
              var' form during the lock; on a successful lock, the shell variable var is  set  to
              the  file  descriptor  used  for  locking.   The  lock will be released if the file
              descriptor is closed by  any  other  means,  for  example  using  `exec  {var}>&-';
              however,  the  form described here performs a safety check that the file descriptor
              is in use for file locking.

              By default the shell waits indefinitely for the lock to  succeed.   The  option  -t
              timeout  specifies  a  timeout  for  the lock in seconds; currently this must be an
              integer.  The shell will attempt to lock the file once a second during this period.
              If the attempt times out, status 2 is returned.

              If  the  option -e is given, the file descriptor for the lock is preserved when the
              shell uses exec to start a new process; otherwise it is closed at  that  point  and
              the lock released.

              If  the  option  -r  is  given,  the  lock is only for reading, otherwise it is for
              reading and writing.  The file descriptor is opened accordingly.

       zsystem supports subcommand
              The builtin zsystem's subcommand supports  tests  whether  a  given  subcommand  is
              supported.   It returns status 0 if so, else status 1.  It operates silently unless
              there was a syntax error (i.e. the wrong number of arguments), in which case status
              255 is returned.  Status 1 can indicate one of two things:  subcommand is known but
              not supported by the current operating system, or subcommand is not known (possibly
              because this is an older version of the shell before it was implemented).

   Math Functions
       systell(fd)
              The systell math function returns the current file position for the file descriptor
              passed as an argument.

   Parameters
       errnos A readonly array of the names of errors defined on the system.  These are typically
              macros defined in C by including the system header file errno.h.  The index of each
              name (assuming the option KSH_ARRAYS is unset) corresponds  to  the  error  number.
              Error numbers num before the last known error which have no name are given the name
              Enum in the array.

              Note that aliases for errors are not handled; only the canonical name is used.

       sysparams
              A readonly associative array.  The keys are:

              pid    Returns the process ID of the current process, even in  subshells.   Compare
                     $$, which returns the process ID of the main shell process.

              ppid   Returns  the  process  ID  of  the  parent  of  the current process, even in
                     subshells.  Compare $PPID, which returns the process ID of the parent of the
                     main shell process.

THE ZSH/NET/TCP MODULE

       The zsh/net/tcp module makes available one builtin command:

       ztcp [ -acflLtv ] [ -d fd ] [ args ]
              ztcp  is  implemented as a builtin to allow full use of shell command line editing,
              file I/O, and job control mechanisms.

              If ztcp is run with no options, it will output the contents of its session table.

              If it is run with only the option -L, it will output the contents  of  the  session
              table  in  a format suitable for automatic parsing.  The option is ignored if given
              with a command to open or close a session.  The output consists of a set of  lines,
              one per session, each containing the following elements separated by spaces:

              File descriptor
                     The  file  descriptor in use for the connection.  For normal inbound (I) and
                     outbound (O) connections this may be read and written  by  the  usual  shell
                     mechanisms.  However, it should only be close with `ztcp -c'.

              Connection type
                     A letter indicating how the session was created:

                     Z      A session created with the zftp command.

                     L      A connection opened for listening with `ztcp -l'.

                     I      An inbound connection accepted with `ztcp -a'.

                     O      An outbound connection created with `ztcp host ...'.

              The local host
                     This  is  usually  set  to  an  all-zero  IP  address  as the address of the
                     localhost is irrelevant.

              The local port
                     This is likely to be zero unless the connection is for listening.

              The remote host
                     This is the fully qualified domain name of the peer, if available,  else  an
                     IP  address.   It  is  an  all-zero  IP  address  for  a  session opened for
                     listening.

              The remote port
                     This is zero for a connection opened for listening.

   Outbound Connections
       ztcp [ -v ] [ -d fd ] host [ port ]
              Open a new TCP connection to host.  If the port is omitted, it will default to port
              23.   The  connection  will  be  added to the session table and the shell parameter
              REPLY will be set to the file descriptor associated with that connection.

              If -d is specified, its argument will be taken as the target  file  descriptor  for
              the connection.

              In order to elicit more verbose output, use -v.

   Inbound Connections
       ztcp -l [ -v ] [ -d fd ] port
              ztcp  -l will open a socket listening on TCP port.  The socket will be added to the
              session table and the shell parameter REPLY will be  set  to  the  file  descriptor
              associated with that listener.

              If  -d  is  specified, its argument will be taken as the target file descriptor for
              the connection.

              In order to elicit more verbose output, use -v.

       ztcp -a [ -tv ] [ -d targetfd ] listenfd
              ztcp -a will accept an incoming connection to the port  associated  with  listenfd.
              The  connection  will  be  added to the session table and the shell parameter REPLY
              will be set to the file descriptor associated with the inbound connection.

              If -d is specified, its argument will be taken as the target  file  descriptor  for
              the connection.

              If  -t  is  specified,  ztcp  will  return  if  no  incoming connection is pending.
              Otherwise it will wait for one.

              In order to elicit more verbose output, use -v.

   Closing Connections
       ztcp -cf [ -v ] [ fd ]
       ztcp -c [ -v ] [ fd ]
              ztcp -c will close the socket associated with fd.  The socket will be removed  from
              the  session  table.   If  fd  is  not specified, ztcp will close everything in the
              session table.

              Normally, sockets registered by zftp (see zshmodules(1) )  cannot  be  closed  this
              way.  In order to force such a socket closed, use -f.

              In order to elicit more verbose output, use -v.

   Example
       Here  is  how to create a TCP connection between two instances of zsh.  We need to pick an
       unassigned port; here we use the randomly chosen 5123.

       On host1,
              zmodload zsh/net/tcp
              ztcp -l 5123
              listenfd=$REPLY
              ztcp -a $listenfd
              fd=$REPLY
       The second from last command blocks until there is an incoming connection.

       Now create a connection from host2 (which may, of course, be the same machine):
              zmodload zsh/net/tcp
              ztcp host1 5123
              fd=$REPLY

       Now on each host, $fd contains a file descriptor for talking to the other.   For  example,
       on host1:
              print This is a message >&$fd
       and on host2:
              read -r line <&$fd; print -r - $line
       prints `This is a message'.

       To tidy up, on host1:
              ztcp -c $listenfd
              ztcp -c $fd
       and on host2
              ztcp -c $fd

THE ZSH/TERMCAP MODULE

       The zsh/termcap module makes available one builtin command:

       echotc cap [ arg ... ]
              Output  the  termcap  value  corresponding  to  the  capability  cap, with optional
              arguments.

       The zsh/termcap module makes available one parameter:

       termcap
              An associative array that maps termcap capability codes to their values.

THE ZSH/TERMINFO MODULE

       The zsh/terminfo module makes available one builtin command:

       echoti cap [ arg ]
              Output the terminfo value corresponding to the capability  cap,  instantiated  with
              arg if applicable.

       The zsh/terminfo module makes available one parameter:

       terminfo
              An associative array that maps terminfo capability names to their values.

THE ZSH/ZFTP MODULE

       The zsh/zftp module makes available one builtin command:

       zftp subcommand [ args ]
              The  zsh/zftp  module  is  a  client  for  FTP  (file  transfer  protocol).   It is
              implemented as a builtin to allow full use of shell command line editing, file I/O,
              and  job  control  mechanisms.   Often,  users  will  access it via shell functions
              providing a more powerful interface; a set is provided with  the  zsh  distribution
              and is described in zshzftpsys(1).  However, the zftp command is entirely usable in
              its own right.

              All commands consist of the command name zftp followed by the name of a subcommand.
              These  are  listed  below.   The  return  status  of each subcommand is supposed to
              reflect the success or failure of the remote operation.  See a description  of  the
              variable  ZFTP_VERBOSE for more information on how responses from the server may be
              printed.

   Subcommands
       open host[:port] [ user [ password [ account ] ] ]
              Open a new FTP session to host, which may be the name of a TCP/IP connected host or
              an  IP  number  in  the  standard  dot  notation.   If  the argument is in the form
              host:port, open a connection to TCP port port instead of the standard FTP port  21.
              This  may  be  the  name  of  a  TCP  service  or a number:  see the description of
              ZFTP_PORT below for more information.

              If IPv6 addresses in colon format are used, the host should be surrounded by quoted
              square    brackets    to    distinguish    it    from   the   port,   for   example
              '[fe80::203:baff:fe02:8b56]'.  For consistency this is allowed with  all  forms  of
              host.

              Remaining  arguments are passed to the login subcommand.  Note that if no arguments
              beyond host are supplied, open will not automatically call login.  If no  arguments
              at all are supplied, open will use the parameters set by the params subcommand.

              After  a  successful  open,  the  shell variables ZFTP_HOST, ZFTP_PORT, ZFTP_IP and
              ZFTP_SYSTEM are available; see `Variables' below.

       login [ name [ password [ account ] ] ]
       user [ name [ password [ account ] ] ]
              Login the user name with parameters password and account.  Any  of  the  parameters
              can  be  omitted,  and  will  be read from standard input if needed (name is always
              needed).  If standard input is a terminal, a prompt for each one will be printed on
              standard  error  and password will not be echoed.  If any of the parameters are not
              used, a warning message is printed.

              After a successful login, the shell variables ZFTP_USER, ZFTP_ACCOUNT and  ZFTP_PWD
              are available; see `Variables' below.

              This command may be re-issued when a user is already logged in, and the server will
              first be reinitialized for a new user.

       params [ host [ user [ password [ account ] ] ] ]
       params -
              Store the given parameters for a later open command with no arguments.  Only  those
              given  on  the  command  line  will  be remembered.  If no arguments are given, the
              parameters currently set are printed, although the password will appear as  a  line
              of stars; the return status is one if no parameters were set, zero otherwise.

              Any  of  the  parameters  may be specified as a `?', which may need to be quoted to
              protect it from shell expansion.  In this case, the appropriate parameter  will  be
              read  from  stdin  as  with  the  login  subcommand,  including special handling of
              password.  If the `?' is followed by a string, that  is  used  as  the  prompt  for
              reading the parameter instead of the default message (any necessary punctuation and
              whitespace should be included at the end of the prompt).  The first letter  of  the
              parameter  (only)  may be quoted with a `\'; hence an argument "\\$word" guarantees
              that the string from the shell parameter $word will be treated  literally,  whether
              or not it begins with a `?'.

              If instead a single `-' is given, the existing parameters, if any, are deleted.  In
              that case, calling open with no arguments will cause an error.

              The list of parameters is not deleted after a close, however it will be deleted  if
              the zsh/zftp module is unloaded.

              For example,

                     zftp params ftp.elsewhere.xx juser '?Password for juser: '

              will  store  the  host ftp.elsewhere.xx and the user juser and then prompt the user
              for the corresponding password with the given prompt.

       test   Test the connection; if the server has reported that it has closed  the  connection
              (maybe due to a timeout), return status 2; if no connection was open anyway, return
              status 1; else return status 0.  The test subcommand is silent, apart from messages
              printed by the $ZFTP_VERBOSE mechanism, or error messages if the connection closes.
              There is no network overhead for this test.

              The test is only supported on systems with either the select(2) or  poll(2)  system
              calls; otherwise the message `not supported on this system' is printed instead.

              The  test  subcommand  will  automatically  be  called  at  the  start of any other
              subcommand for the current session when a connection is open.

       cd directory
              Change the remote directory to directory.  Also alters the shell variable ZFTP_PWD.

       cdup   Change the remote directory to the one higher in the directory tree.  Note that  cd
              .. will also work correctly on non-UNIX systems.

       dir [ arg ... ]
              Give  a (verbose) listing of the remote directory.  The args are passed directly to
              the server. The command's behaviour is implementation dependent, but a UNIX  server
              will  typically interpret args as arguments to the ls command and with no arguments
              return the result of `ls -l'. The directory is listed to standard output.

       ls [ arg ... ]
              Give a (short) listing of the remote directory.  With no arg, produces a  raw  list
              of  the  files  in  the  directory, one per line.  Otherwise, up to vagaries of the
              server implementation, behaves similar to dir.

       type [ type ]
              Change the type for the transfer to type, or print the  current  type  if  type  is
              absent.   The  allowed  values are `A' (ASCII), `I' (Image, i.e. binary), or `B' (a
              synonym for `I').

              The FTP default for a transfer is ASCII.  However, if zftp finds  that  the  remote
              host  is  a  UNIX  machine  with  8-bit byes, it will automatically switch to using
              binary for file transfers upon open.  This can subsequently be overridden.

              The transfer type is only passed to the remote  host  when  a  data  connection  is
              established; this command involves no network overhead.

       ascii  The same as type A.

       binary The same as type I.

       mode [ S | B ]
              Set  the  mode  type to stream (S) or block (B).  Stream mode is the default; block
              mode is not widely supported.

       remote file ...
       local [ file ... ]
              Print the size and last modification time of the remote or local files.   If  there
              is  more  than  one  item  on the list, the name of the file is printed first.  The
              first number is the file size, the second is the last modification time of the file
              in  the  format  CCYYMMDDhhmmSS  consisting of year, month, date, hour, minutes and
              seconds in GMT.  Note that this format, including the  length,  is  guaranteed,  so
              that  time strings can be directly compared via the [[ builtin's < and > operators,
              even if they are too long to be represented as integers.

              Not all servers support the commands for  retrieving  this  information.   In  that
              case,  the  remote  command  will  print nothing and return status 2, compared with
              status 1 for a file not found.

              The local command (but not remote) may be used with no arguments, in which case the
              information  comes  from  examining file descriptor zero.  This is the same file as
              seen by a put command with no further redirection.

       get file ...
              Retrieve all files from the server, concatenating them and sending them to standard
              output.

       put file ...
              For  each  file,  read  a file from standard input and send that to the remote host
              with the given name.

       append file ...
              As put, but if the remote file already exists, data is appended to  it  instead  of
              overwriting it.

       getat file point
       putat file point
       appendat file point
              Versions of get, put and append which will start the transfer at the given point in
              the remote file.  This is  useful  for  appending  to  an  incomplete  local  file.
              However, note that this ability is not universally supported by servers (and is not
              quite the behaviour specified by the standard).

       delete file ...
              Delete the list of files on the server.

       mkdir directory
              Create a new directory directory on the server.

       rmdir directory
              Delete the directory directory  on the server.

       rename old-name new-name
              Rename file old-name to new-name on the server.

       site arg ...
              Send a host-specific command to the server.  You will probably only  need  this  if
              instructed by the server to use it.

       quote arg ...
              Send  the  raw FTP command sequence to the server.  You should be familiar with the
              FTP command set as defined in  RFC959  before  doing  this.   Useful  commands  may
              include STAT and HELP.  Note also the mechanism for returning messages as described
              for the variable ZFTP_VERBOSE below, in  particular  that  all  messages  from  the
              control connection are sent to standard error.

       close
       quit   Close  the  current  data  connection.  This unsets the shell parameters ZFTP_HOST,
              ZFTP_PORT, ZFTP_IP, ZFTP_SYSTEM, ZFTP_USER, ZFTP_ACCOUNT, ZFTP_PWD,  ZFTP_TYPE  and
              ZFTP_MODE.

       session [ sessname ]
              Allows  multiple  FTP  sessions  to be used at once.  The name of the session is an
              arbitrary string of characters; the default session is called `default'.   If  this
              command  is called without an argument, it will list all the current sessions; with
              an argument, it will either switch to the  existing  session  called  sessname,  or
              create a new session of that name.

              Each session remembers the status of the connection, the set of connection-specific
              shell parameters (the same set as are unset when a connection closes, as  given  in
              the  description  of  close),  and  any  user  parameters specified with the params
              subcommand.  Changing to a previous session restores those values;  changing  to  a
              new  session initialises them in the same way as if zftp had just been loaded.  The
              name of the current session is given by the parameter ZFTP_SESSION.

       rmsession [ sessname ]
              Delete a session; if a name is not given, the current session is deleted.   If  the
              current  session  is deleted, the earliest existing session becomes the new current
              session, otherwise the current session  is  not  changed.   If  the  session  being
              deleted  is the only one, a new session called `default' is created and becomes the
              current session; note that this is a new session even if the session being  deleted
              is  also  called  `default'.  It  is recommended that sessions not be deleted while
              background commands which use zftp are still active.

   Parameters
       The following shell parameters are used by zftp.  Currently none of them are special.

       ZFTP_TMOUT
              Integer.  The time in seconds to wait for a network operation  to  complete  before
              returning an error.  If this is not set when the module is loaded, it will be given
              the default value 60.  A value of zero turns off timeouts.  If a timeout occurs  on
              the  control  connection  it will be closed.  Use a larger value if this occurs too
              frequently.

       ZFTP_IP
              Readonly.  The IP address of the current connection in dot notation.

       ZFTP_HOST
              Readonly.  The hostname of the current remote server.  If the host was opened as an
              IP  number,  ZFTP_HOST  contains  that  instead; this saves the overhead for a name
              lookup, as IP numbers are most commonly used when a nameserver is unavailable.

       ZFTP_PORT
              Readonly.  The number of the remote TCP port to which the connection is open  (even
              if  the  port  was  originally  specified as a named service).  Usually this is the
              standard FTP port, 21.

              In the unlikely event that your system does not  have  the  appropriate  conversion
              functions,  this  appears  in network byte order.  If your system is little-endian,
              the port then consists of two swapped bytes and the standard port will be  reported
              as  5376.   In that case, numeric ports passed to zftp open will also need to be in
              this format.

       ZFTP_SYSTEM
              Readonly.  The system type string returned by the server in response to an FTP SYST
              request.   The  most  interesting case is a string beginning "UNIX Type: L8", which
              ensures maximum compatibility with a local UNIX host.

       ZFTP_TYPE
              Readonly.  The type to be used for data transfers , either `A' or  `I'.    Use  the
              type subcommand to change this.

       ZFTP_USER
              Readonly.  The username currently logged in, if any.

       ZFTP_ACCOUNT
              Readonly.   The  account  name  of  the  current user, if any.  Most servers do not
              require an account name.

       ZFTP_PWD
              Readonly.  The current directory on the server.

       ZFTP_CODE
              Readonly.  The three digit code of the last FTP reply from the server as a  string.
              This  can still be read after the connection is closed, and is not changed when the
              current session changes.

       ZFTP_REPLY
              Readonly.  The last line of the last reply sent by the server.  This can  still  be
              read  after  the  connection is closed, and is not changed when the current session
              changes.

       ZFTP_SESSION
              Readonly.  The name of the current FTP session; see the description of the  session
              subcommand.

       ZFTP_PREFS
              A  string of preferences for altering aspects of zftp's behaviour.  Each preference
              is a single character.  The following are defined:

              P      Passive:  attempt to make the remote server initiate data  transfers.   This
                     is slightly more efficient than sendport mode.  If the letter S occurs later
                     in the string, zftp will use sendport mode if passive mode is not available.

              S      Sendport:  initiate transfers by the  FTP  PORT  command.   If  this  occurs
                     before any P in the string, passive mode will never be attempted.

              D      Dumb:   use  only  the  bare  minimum  of  FTP  commands.  This prevents the
                     variables ZFTP_SYSTEM and  ZFTP_PWD  from  being  set,  and  will  mean  all
                     connections  default to ASCII type.  It may prevent ZFTP_SIZE from being set
                     during a transfer if the server does not send it anyway (many servers do).

              If ZFTP_PREFS is not set when zftp is loaded, it will be set to a default of  `PS',
              i.e. use passive mode if available, otherwise fall back to sendport mode.

       ZFTP_VERBOSE
              A  string  of digits between 0 and 5 inclusive, specifying which responses from the
              server should be printed.  All responses go to  standard  error.   If  any  of  the
              numbers 1 to 5 appear in the string, raw responses from the server with reply codes
              beginning with that digit will be printed to standard error.  The  first  digit  of
              the three digit reply code is defined by RFC959 to correspond to:

              1.     A positive preliminary reply.

              2.     A positive completion reply.

              3.     A positive intermediate reply.

              4.     A transient negative completion reply.

              5.     A permanent negative completion reply.

              It  should  be  noted that, for unknown reasons, the reply `Service not available',
              which forces termination of a connection, is classified  as  421,  i.e.  `transient
              negative', an interesting interpretation of the word `transient'.

              The  code  0  is  special:   it  indicates  that all but the last line of multiline
              replies read from the server will be printed  to  standard  error  in  a  processed
              format.   By convention, servers use this mechanism for sending information for the
              user to read.  The appropriate reply code, if it matches the same  response,  takes
              priority.

              If ZFTP_VERBOSE is not set when zftp is loaded, it will be set to the default value
              450, i.e., messages destined for the user and all errors will be printed.   A  null
              string is valid and specifies that no messages should be printed.

   Functions
       zftp_chpwd
              If  this function is set by the user, it is called every time the directory changes
              on the server, including when a user is logged in, or when a connection is  closed.
              In  the  last  case,  $ZFTP_PWD  will  be  unset; otherwise it will reflect the new
              directory.

       zftp_progress
              If this function is set by the user, it will be called during a get, put or  append
              operation each time sufficient data has been received from the host.  During a get,
              the data is sent to standard output, so it is vital that this function should write
              to standard error or directly to the terminal, not to standard output.

              When  it  is  called  with  a  transfer in progress, the following additional shell
              parameters are set:

              ZFTP_FILE
                     The name of the remote file being transferred from or to.

              ZFTP_TRANSFER
                     A G for a get operation and a P for a put operation.

              ZFTP_SIZE
                     The total size of the complete file being transferred: the same as the first
                     value  provided  by  the remote and local subcommands for a particular file.
                     If the server cannot supply this value for a remote file being retrieved, it
                     will  not  be  set.   If input is from a pipe the value may be incorrect and
                     correspond simply to a full pipe buffer.

              ZFTP_COUNT
                     The amount of data so far transferred; a number between zero and $ZFTP_SIZE,
                     if that is set.  This number is always available.

              The   function  is  initially  called  with  ZFTP_TRANSFER  set  appropriately  and
              ZFTP_COUNT set to zero.  After the transfer  is  finished,  the  function  will  be
              called  one more time with ZFTP_TRANSFER set to GF or PF, in case it wishes to tidy
              up.  It is otherwise never called twice with the same value of ZFTP_COUNT.

              Sometimes the progress meter may cause disruption.  It is up to the user to  decide
              whether the function should be defined and to use unfunction when necessary.

   Problems
       A  connection  may  not  be  opened  in  the  left hand side of a pipe as this occurs in a
       subshell and the file information is not updated in the main shell.  In the case  of  type
       or  mode  changes or closing the connection in a subshell, the information is returned but
       variables are not updated until the next call to zftp.  Other status changes in  subshells
       will not be reflected by changes to the variables (but should be otherwise harmless).

       Deleting  sessions  while  a  zftp command is active in the background can have unexpected
       effects, even if it does not use the session being deleted.  This  is  because  all  shell
       subprocesses  share  information  on  the state of all connections, and deleting a session
       changes the ordering of that information.

       On some operating systems, the control connection is not valid after  a  fork(),  so  that
       operations in subshells, on the left hand side of a pipeline, or in the background are not
       possible, as they should be.  This is presumably a bug in the operating system.

THE ZSH/ZLE MODULE

       The zsh/zle module contains the Zsh Line Editor.  See zshzle(1).

THE ZSH/ZLEPARAMETER MODULE

       The zsh/zleparameter module defines two special parameters that  can  be  used  to  access
       internal information of the Zsh Line Editor (see zshzle(1)).

       keymaps
              This array contains the names of the keymaps currently defined.

       widgets
              This  associative  array  contains  one  entry  per widget defined. The name of the
              widget is the key and the value gives information about the widget.  It  is  either
              the  string  `builtin'  for  builtin  widgets, a string of the form `user:name' for
              user-defined widgets, where name is the name of the shell function implementing the
              widget,  or  it  is  a  string  of  the form `completion:type:name', for completion
              widgets. In the last case type is the name of the builtin  widgets  the  completion
              widget  imitates  in  its  behavior  and  name  is  the  name of the shell function
              implementing the completion widget.

THE ZSH/ZPROF MODULE

       When loaded, the zsh/zprof causes shell functions to be profiled.  The  profiling  results
       can be obtained with the zprof builtin command made available by this module.  There is no
       way to turn profiling off other than unloading the module.

       zprof [ -c ]
              Without the -c option, zprof lists  profiling  results  to  standard  output.   The
              format is comparable to that of commands like gprof.

              At the top there is a summary listing all functions that were called at least once.
              This summary is sorted in decreasing order of the amount of  time  spent  in  each.
              The lines contain the number of the function in order, which is used in other parts
              of the list in suffixes of the form `[num]', then the number of calls made  to  the
              function.   The  next  three  columns  list  the  time in milliseconds spent in the
              function and its descendants,  the  average  time  in  milliseconds  spent  in  the
              function and its descendants per call and the percentage of time spent in all shell
              functions used in this function and its descendants.  The following  three  columns
              give the same information, but counting only the time spent in the function itself.
              The final column shows the name of the function.

              After the summary, detailed information about every function that  was  invoked  is
              listed, sorted in decreasing order of the amount of time spent in each function and
              its descendants.  Each of these entries consists of descriptions for the  functions
              that  called  the  function  described, the function itself, and the functions that
              were called from it.  The description for the function itself has the  same  format
              as in the summary (and shows the same information).  The other lines don't show the
              number of the function at the beginning and have their function named  indented  to
              make  it  easier  to  distinguish  the  line  showing the function described in the
              section from the surrounding lines.

              The information shown in this case is almost the same as in the summary,  but  only
              refers  to the call hierarchy being displayed.  For example, for a calling function
              the column showing the total running time lists the time  spent  in  the  described
              function  and  its  descendants  only  for  the  times when it was called from that
              particular calling function.  Likewise, for a called function, this  columns  lists
              the  total time spent in the called function and its descendants only for the times
              when it was called from the function described.

              Also in this case, the column showing the number of calls to a function also  shows
              a slash and then the total number of invocations made to the called function.

              As  long  as  the  zsh/zprof  module is loaded, profiling will be done and multiple
              invocations of the zprof builtin command will show the times and numbers  of  calls
              since  the  module  was loaded.  With the -c option, the zprof builtin command will
              reset its internal counters and will not show the listing.

THE ZSH/ZPTY MODULE

       The zsh/zpty module offers one builtin:

       zpty [ -e ] [ -b ] name [ arg ... ]
              The arguments following name are concatenated with spaces between, then executed as
              a  command,  as  if  passed  to  the  eval builtin.  The command runs under a newly
              assigned pseudo-terminal; this is useful  for  running  commands  non-interactively
              which  expect an interactive environment.  The name is not part of the command, but
              is used to refer to this command in later calls to zpty.

              With the -e option, the pseudo-terminal is set up  so  that  input  characters  are
              echoed.

              With  the  -b  option,  input  to  and  output  from  the  pseudo-terminal are made
              non-blocking.

              The shell parameter REPLY is set to the file descriptor assigned to the master side
              of  the  pseudo-terminal.   This  allows  the  terminal  to  be  monitored with ZLE
              descriptor handlers (see zshzle(1)) or manipulated with sysread and  syswrite  (see
              THE  ZSH/SYSTEM  MODULE in zshmodules(1)).  Warning: Use of sysread and syswrite is
              not recommended, use zpty -r and zpty -w unless  you  know  exactly  what  you  are
              doing.

       zpty -d [ name ... ]
              The second form, with the -d option, is used to delete commands previously started,
              by supplying a list of their names.  If no name is given, all commands are deleted.
              Deleting a command causes the HUP signal to be sent to the corresponding process.

       zpty -w [ -n ] name [ string ... ]
              The  -w  option  can be used to send the to command name the given strings as input
              (separated by spaces).  If the -n option is not given, a newline is  added  at  the
              end.

              If no string is provided, the standard input is copied to the pseudo-terminal; this
              may stop before copying the full input if the pseudo-terminal is non-blocking.

              Note that the command under the pseudo-terminal sees  this  input  as  if  it  were
              typed,  so  beware  when  sending special tty driver characters such as word-erase,
              line-kill, and end-of-file.

       zpty -r [ -mt ] name [ param [ pattern ] ]
              The -r option can be used to read the output of the command name.  With only a name
              argument,   the  output  read  is  copied  to  the  standard  output.   Unless  the
              pseudo-terminal is non-blocking, copying continues  until  the  command  under  the
              pseudo-terminal  exits;  when  non-blocking,  only as much output as is immediately
              available is copied.  The return status is zero if any output is copied.

              When also given a param argument, at most one  line  is  read  and  stored  in  the
              parameter named param.  Less than a full line may be read if the pseudo-terminal is
              non-blocking.  The return status is zero if at least one  character  is  stored  in
              param.

              If  a  pattern is given as well, output is read until the whole string read matches
              the pattern, even in the non-blocking case.  The  return  status  is  zero  if  the
              string  read  matches  the  pattern,  or if the command has exited but at least one
              character could still be read.  If the option -m is present, the return  status  is
              zero only if the pattern matches.  As of this writing, a maximum of one megabyte of
              output can be consumed this way; if a full megabyte is read  without  matching  the
              pattern, the return status is non-zero.

              In  all  cases, the return status is non-zero if nothing could be read, and is 2 if
              this is because the command has finished.

              If the -r option is combined with the -t  option,  zpty  tests  whether  output  is
              available  before  trying  to  read.   If  no output is available, zpty immediately
              returns the status 1.  When used with a pattern, the behaviour on a failed poll  is
              similar  to  when the command has exited:  the return value is zero if at least one
              character could still be read even if the pattern failed to match.

       zpty -t name
              The -t option without the -r option can be used to test whether the command name is
              still  running.   It returns a zero status if the command is running and a non-zero
              value otherwise.

       zpty [ -L ]
              The last form, without any arguments,  is  used  to  list  the  commands  currently
              defined.   If the -L option is given, this is done in the form of calls to the zpty
              builtin.

THE ZSH/ZSELECT MODULE

       The zsh/zselect module makes available one builtin command:

       zselect [ -rwe ] [ -t timeout ] [ -a array ] [ -A assoc ] [ fd ... ]
              The zselect builtin is a front-end to the `select' system call, which blocks  until
              a  file descriptor is ready for reading or writing, or has an error condition, with
              an optional timeout.  If this is not available on your system, the  command  prints
              an  error  message  and returns status 2 (normal errors return status 1).  For more
              information, see your systems  documentation  for  select(3).   Note  there  is  no
              connection with the shell builtin of the same name.

              Arguments  and  options may be intermingled in any order.  Non-option arguments are
              file descriptors, which must be decimal integers.  By default, file descriptors are
              to  be  tested  for  reading, i.e. zselect will return when data is available to be
              read from the file descriptor, or more precisely, when a read  operation  from  the
              file  descriptor will not block.  After a -r, -w and -e, the given file descriptors
              are to be tested for reading, writing, or error conditions.  These options  and  an
              arbitrary list of file descriptors may be given in any order.

              (The  presence of an `error condition' is not well defined in the documentation for
              many implementations of the select system call.  According to  recent  versions  of
              the  POSIX  specification,  it  is really an exception condition, of which the only
              standard example is out-of-band data received  on  a  socket.   So  zsh  users  are
              unlikely to find the -e option useful.)

              The option `-t timeout' specifies a timeout in hundredths of a second.  This may be
              zero, in which case the file descriptors will simply be  polled  and  zselect  will
              return  immediately.  It is possible to call zselect with no file descriptors and a
              non-zero timeout for use as a finer-grained replacement for `sleep'; note, however,
              the return status is always 1 for a timeout.

              The  option  `-a  array'  indicates  that  array should be set to indicate the file
              descriptor(s) which are ready.  If the option is not given, the array reply will be
              used  for  this  purpose.  The array will contain a string similar to the arguments
              for zselect.  For example,

                     zselect -t 0 -r 0 -w 1

              might return immediately with status 0 and $reply containing `-r 0 -w  1'  to  show
              that both file descriptors are ready for the requested operations.

              The  option  `-A assoc' indicates that the associative array assoc should be set to
              indicate the file descriptor(s) which are ready.  This option overrides the  option
              -a,  nor  will  reply be modified.  The keys of assoc are the file descriptors, and
              the corresponding values are any of the characters `rwe' to indicate the condition.

              The command returns status 0 if some file descriptors are ready  for  reading.   If
              the  operation  timed out, or a timeout of 0 was given and no file descriptors were
              ready, or there was an error, it returns status 1 and the array  will  not  be  set
              (nor  modified  in  any  way).   If  there was an error in the select operation the
              appropriate error message is printed.

THE ZSH/ZUTIL MODULE

       The zsh/zutil module only adds some builtins:

       zstyle [ -L [ pattern [ style ] ] ]
       zstyle [ -e | - | -- ] pattern style string ...
       zstyle -d [ pattern [ style ... ] ]
       zstyle -g name [ pattern [ style ] ]
       zstyle -{a|b|s} context style name [ sep ]
       zstyle -{T|t} context style [ string ... ]
       zstyle -m context style pattern
              This builtin command is used to define and lookup  styles.   Styles  are  pairs  of
              names  and  values,  where  the  values consist of any number of strings.  They are
              stored together with patterns and lookup is done by giving  a  string,  called  the
              `context',  which is compared to the patterns.  The definition stored for the first
              matching pattern will be returned.

              For ordering of comparisons, patterns are searched  from  most  specific  to  least
              specific,  and patterns that are equally specific keep the order in which they were
              defined.  A pattern is considered to be more specific than another if  it  contains
              more  components  (substrings  separated  by  colons)  or  if  the patterns for the
              components are more specific, where  simple  strings  are  considered  to  be  more
              specific than patterns and complex patterns are considered to be more specific than
              the pattern `*'.

              The first form (without arguments) lists the  definitions.   Styles  are  shown  in
              alphabetic order and patterns are shown in the order zstyle will test them.

              If  the  -L  option  is given, listing is done in the form of calls to zstyle.  The
              optional first argument is a pattern which  will  be  matched  against  the  string
              supplied as the pattern for the context; note that this means, for example, `zstyle
              -L ":completion:*"' will match any supplied pattern beginning  `:completion:',  not
              just  ":completion:*":   use  ":completion:\*"  to match that.  The optional second
              argument limits the output to  a  specific  style  (not  a  pattern).   -L  is  not
              compatible with any other options.

              The other forms are the following:

              zstyle [ - | -- | -e ] pattern style string ...
                     Defines  the  given style for the pattern with the strings as the value.  If
                     the -e option is given, the  strings  will  be  concatenated  (separated  by
                     spaces) and the resulting string will be evaluated (in the same way as it is
                     done by the eval builtin command) when the style is looked up.  In this case
                     the parameter `reply' must be assigned to set the strings returned after the
                     evaluation.  Before evaluating the value, reply is unset, and if it is still
                     unset after the evaluation, the style is treated as if it were not set.

              zstyle -d [ pattern [ style ... ] ]
                     Delete  style  definitions.  Without  arguments all definitions are deleted,
                     with a pattern all definitions for that  pattern  are  deleted  and  if  any
                     styles are given, then only those styles are deleted for the pattern.

              zstyle -g name [ pattern [ style ] ]
                     Retrieve  a  style  definition.  The name is used as the name of an array in
                     which the results are stored. Without any further  arguments,  all  patterns
                     defined are returned. With a pattern the styles defined for that pattern are
                     returned and with both a pattern and a style,  the  value  strings  of  that
                     combination is returned.

              The other forms can be used to look up or test patterns.

              zstyle -s context style name [ sep ]
                     The parameter name is set to the value of the style interpreted as a string.
                     If the value contains several strings they are concatenated with spaces  (or
                     with the sep string if that is given) between them.

              zstyle -b context style name
                     The  value  is  stored in name as a boolean, i.e. as the string `yes' if the
                     value has only one string and that string is equal to one of `yes',  `true',
                     `on',  or `1'. If the value is any other string or has more than one string,
                     the parameter is set to `no'.

              zstyle -a context style name
                     The value is stored in  name  as  an  array.  If  name  is  declared  as  an
                     associative  array,  the first, third, etc. strings are used as the keys and
                     the other strings are used as the values.

              zstyle -t context style [ string ... ]
              zstyle -T context style [ string ... ]
                     Test the value of a style, i.e. the -t option only returns  a  status  (sets
                     $?).   Without  any string the return status is zero if the style is defined
                     for at least one matching pattern, has only one string  in  its  value,  and
                     that is equal to one of `true', `yes', `on' or `1'. If any strings are given
                     the status is zero if and only if at least one of the strings is equal to at
                     least  one  of the strings in the value. If the style is defined but doesn't
                     match, the return status is 1. If the style is not defined, the status is 2.

                     The -T option tests the values of the style like -t, but it  returns  status
                     zero (rather than 2) if the style is not defined for any matching pattern.

              zstyle -m context style pattern
                     Match  a  value.  Returns status zero if the pattern matches at least one of
                     the strings in the value.

       zformat -f param format spec ...
       zformat -a array sep spec ...
              This builtin provides two different forms of formatting. The first form is selected
              with  the  -f  option. In this case the format string will be modified by replacing
              sequences starting with a percent sign in it with strings  from  the  specs.   Each
              spec  should  be of the form `char:string' which will cause every appearance of the
              sequence `%char' in format to be replaced by the string.  The `%' sequence may also
              contain optional minimum and maximum field width specifications between the `%' and
              the `char' in the form `%min.maxc', i.e. the minimum field width is given first and
              if  the  maximum field width is used, it has to be preceded by a dot.  Specifying a
              minimum field width makes the result be padded with spaces  to  the  right  if  the
              string is shorter than the requested width.  Padding to the left can be achieved by
              giving a negative minimum field width.  If a maximum field width is specified,  the
              string  will  be truncated after that many characters.  After all `%' sequences for
              the given specs have  been  processed,  the  resulting  string  is  stored  in  the
              parameter param.

              The %-escapes also understand ternary expressions in the form used by prompts.  The
              % is followed by a `(' and then an ordinary format specifier character as described
              above.   There may be a set of digits either before or after the `('; these specify
              a test number, which defaults to zero.  Negative  numbers  are  also  allowed.   An
              arbitrary  delimiter character follows the format specifier, which is followed by a
              piece of `true' text, the delimiter character again, a piece of `false' text, and a
              closing  parenthesis.  The complete expression (without the digits) thus looks like
              `%(X.text1.text2)', except that the `.' character is arbitrary.   The  value  given
              for  the  format  specifier  in  the  char:string  expressions  is  evaluated  as a
              mathematical expression, and compared with the test number.  If they are the  same,
              text1  is  output,  else text2 is output.  A parenthesis may be escaped in text2 as
              %).  Either of text1 or text2 may contain nested %-escapes.

              For example:

                     zformat -f REPLY "The answer is '%3(c.yes.no)'." c:3

              outputs "The answer is 'yes'." to REPLY since the value for the format specifier  c
              is 3, agreeing with the digit argument to the ternary expression.

              The  second form, using the -a option, can be used for aligning strings.  Here, the
              specs are of the form `left:right' where `left' and `right' are arbitrary  strings.
              These  strings  are  modified by replacing the colons by the sep string and padding
              the left strings with spaces to the right so that the sep  strings  in  the  result
              (and hence the right strings after them) are all aligned if the strings are printed
              below each other.  All strings without a colon are left unchanged and  all  strings
              with  an  empty  right  string  have the trailing colon removed.  In both cases the
              lengths of the strings are not used to determine how the other strings  are  to  be
              aligned.  The resulting strings are stored in the array.

       zregexparse
              This implements some internals of the _regex_arguments function.

       zparseopts [ -DKME ] [ -a array ] [ -A assoc ] spec ...
              This  builtin  simplifies the parsing of options in positional parameters, i.e. the
              set of arguments given by $*.  Each spec describes one option and must  be  of  the
              form  `opt[=array]'.   If  an  option  described  by opt is found in the positional
              parameters it is copied into the  array  specified  with  the  -a  option;  if  the
              optional `=array' is given, it is instead copied into that array.

              Note  that it is an error to give any spec without an `=array' unless one of the -a
              or -A options is used.

              Unless the -E option is given,  parsing  stops  at  the  first  string  that  isn't
              described  by one of the specs.  Even with -E, parsing always stops at a positional
              parameter equal to `-' or `--'.

              The opt description must be one of the following.  Any of  the  special  characters
              can appear in the option name provided it is preceded by a backslash.

              name
              name+  The  name  is  the name of the option without the leading `-'.  To specify a
                     GNU-style long option, one of the usual two leading `-' must be included  in
                     name; for example, a `--file' option is represented by a name of `-file'.

                     If a `+' appears after name, the option is appended to array each time it is
                     found in the positional parameters; without the `+' only the last occurrence
                     of the option is preserved.

                     If  one  of  these  forms  is used, the option takes no argument, so parsing
                     stops if the next positional parameter does not also begin with `-'  (unless
                     the -E option is used).

              name:
              name:-
              name:: If  one  or  two  colons  are  given, the option takes an argument; with one
                     colon, the argument is mandatory and with two colons it  is  optional.   The
                     argument is appended to the array after the option itself.

                     An  optional  argument is put into the same array element as the option name
                     (note that this makes empty  strings  as  arguments  indistinguishable).   A
                     mandatory  argument  is  added as a separate element unless the `:-' form is
                     used, in which case the argument is put into the same element.

                     A `+' as described above may appear between the name and the first colon.

              The options of zparseopts itself are:

              -a array
                     As described above, this names the default  array  in  which  to  store  the
                     recognised options.

              -A assoc
                     If  this  is  given,  the  options  and  their  values  are also put into an
                     associative array with the option names as keys and the arguments  (if  any)
                     as the values.

              -D     If  this  option is given, all options found are removed from the positional
                     parameters of the calling shell or shell function, up to but  not  including
                     any not described by the specs.  This is similar to using the shift builtin.

              -K     With  this  option,  the  arrays  specified  with the -a option and with the
                     `=array' forms are kept unchanged when none of the specs for them  is  used.
                     Otherwise  the  entire  array  is  replaced  when  any of the specs is used.
                     Individual elements of associative arrays specified with the -A  option  are
                     preserved  by -K.  This allows assignment of default values to arrays before
                     calling zparseopts.

              -M     This changes the assignment rules to implement a map among equivalent option
                     names.   If any spec uses the `=array' form, the string array is interpreted
                     as the name of another spec, which is used to  choose  where  to  store  the
                     values.   If  no  other spec is found, the values are stored as usual.  This
                     changes only the way the values are stored, not the way  $*  is  parsed,  so
                     results   may   be   unpredictable   if   the   `name+'  specifier  is  used
                     inconsistently.

              -E     This changes the parsing rules to not stop at the first  string  that  isn't
                     described  by  one  of  the  specs.   It can be used to test for or (if used
                     together with -D) extract options and their arguments,  ignoring  all  other
                     options and arguments that may be in the positional parameters.

              For example,

                     set -- -a -bx -c y -cz baz -cend
                     zparseopts a=foo b:=bar c+:=bar

              will have the effect of

                     foo=(-a)
                     bar=(-b x -c y -c z)

              The arguments from `baz' on will not be used.

              As an example for the -E option, consider:

                     set -- -a x -b y -c z arg1 arg2
                     zparseopts -E -D b:=bar

              will have the effect of

                     bar=(-b y)
                     set -- -a x -c z arg1 arg2

              I.e.,  the option -b and its arguments are taken from the positional parameters and
              put into the array bar.

              The -M option can be used like this:

                     set -- -a -bx -c y -cz baz -cend
                     zparseopts -A bar -M a=foo b+: c:=b

              to have the effect of

                     foo=(-a)
                     bar=(-a '' -b xyz)