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ZSHMODULES(1)               General Commands Manual               ZSHMODULES(1)

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 in-
       stallation 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 (privi-
              lege) 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  evalua-
              tions.

       zsh/nearcolor
              Map colours to the nearest colour in the available palette.

       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/param/private
              Builtins  for managing private-scoped parameters in function con-
              text.

       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/watch
              Reporting of login and logout events.

       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  file-
              name.

       zlistattr [ -h ] filename [ parameter ]
              List the extended attributes currently set on the specified file-
              name.  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) capabil-
       ity 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 capa-
              bilities, 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  suc-
              cessful, and non-zero on error.

              The  target of clone should be an unused terminal, such as an un-
              used 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  al-
              ready  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 in-
              put 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  zshcom-
       pctl(1).   The  other  builtin command, compcall can be used in user-de-
       fined 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,  `zmod-
       load zsh/complist' is required.

       The parameters ZLS_COLORS and ZLS_COLOURS describe how matches are high-
       lighted.  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, sym-
              bolic links are dereferenced and the target file used  to  deter-
              mine 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  file-
              names 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 (`*') fol-
       lowed 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 as-
       terisk (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.
       Patterns may be matched against completions, descriptions (possibly with
       spaces  appended  for padding), or lines consisting of a completion fol-
       lowed by a description.  For consistent coloring it may be necessary  to
       use more than one pattern or a pattern with backreferences.

       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 de-
       fined.

       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  zshcon-
       trib(1)).    For   example,   after   loading   colors,  one  could  use
       `$color[red]'  to  get  the  code   for   foreground   color   red   and
       `$color[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.  In-
       stead, 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 bot-
       tom,  waiting  for  a  keypress after temporarily switching to the list-
       scroll 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 se-
       lection  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 MENUSE-
       LECT 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 sup-
       ports 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 se-
       lect-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 comple-
       tion 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, respec-
       tively.

       Selecting matches is done by moving the mark around using the zle  move-
       ment  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 allow-
              ing 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 se-
              lection 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 leav-
              ing 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  in-
              serted  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  dis-
              played; 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 pos-
       sible 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 com-
       mand 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 menuse-
       lect keymap can be modified directly using the bindkey  builtin  command
       (see  zshmodules(1)). For example, to make the return key leave menu se-
       lection 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 com-
       mands  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 op-
              tions 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 descrip-
              tions must be given as the second argument and  the  descriptions
              (if any) will be shown.  All other arguments are like the defini-
              tion 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  re-
              moving 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  quot-
              ing  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 parame-
              ters 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 para-
              meters, so that a leading equal sign will not be quoted.

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

       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 ]
       zcurses resize height width [ endwin | nosave | endwin_nosave ]
              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 be-
              gin_y and column begin_x of the screen.  targetwin  is  a  string
              and  refers  to  the  name  of a window that is not currently as-
              signed.  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 con-
              tents  is  shared  with  the parent's memory.  Subwindows must be
              deleted before their parent.  Note that the coordinates  of  sub-
              windows 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.  re-
              fresh without an argument causes the screen to be cleared and re-
              drawn.  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  fore-
              ground/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  at-
              tributes  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  de-
              fault/default  is  always available. To use more than the 8 named
              colors (red, green, etc.) construct the fg_col/bg_col pairs where
              fg_col and bg_col are decimal integers, e.g 128/200.  The maximum
              color value is 254 if the terminal supports 256 colors.

              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 charac-
              ters  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 para-
              meter REPLY.

              If  both  param and kparam are supplied, the key is read in `key-
              pad' 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  dou-
              ble-  or  triple-clicked,  or  pressed or released with a config-
              urable 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 de-
                     vices 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 immedi-
                     ately (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 win-
              dow; 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  han-
              dling  is possible, else status 1.  Otherwise, the possible argu-
              ments (which may be combined on the same  command  line)  are  as
              follows.   delay  num  sets the maximum delay in milliseconds be-
              tween 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.   How-
              ever,  it  appears reports for mouse motion are not currently im-
              plemented.

              The subcommand timeout specifies a timeout value for  input  from
              targetwin.   If intval is negative, `zcurses input' waits indefi-
              nitely for a character to be typed; this is the default.  If int-
              val is zero, `zcurses input' returns immediately; if there is ty-
              peahead it is returned, else no input is done and status 1 is re-
              turned.  If intval is positive, `zcurses input' waits intval mil-
              liseconds for input and if there is none at the end of  that  pe-
              riod 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 at-
              tributes other than color that apply to  the  character,  as  set
              with the subcommand attr, appear as additional elements.

              The subcommand resize resizes stdscr and all windows to given di-
              mensions  (windows that stick out from the new dimensions are re-
              sized down). The underlying curses extension  (resize_term  call)
              can  be unavailable. To verify, zeroes can be used for height and
              width. If the result of  the  subcommand  is  0,  resize_term  is
              available (2 otherwise). Tests show that resizing can be normally
              accomplished  by calling zcurses end and zcurses refresh. The re-
              size subcommand is provided for versatility. Multiple system con-
              figurations have been checked and zcurses end and zcurses refresh
              are still needed for correct terminal state after resize. To  in-
              voke  them  with resize, use endwin argument.  Using nosave argu-
              ment will cause new terminal state to not be saved internally  by
              zcurses.  This  is  also provided for versatility and should nor-
              mally be not needed.

   Parameters
       ZCURSES_COLORS
              Readonly integer.  The maximum number of colors the terminal sup-
              ports.  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  ini-
              tialised  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;  avail-
              able 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 | -n ] format [ epochtime [ nanoseconds ] ]
       strftime -r [ -q ] [ -s scalar | -n ] format timestring
              Output  the date in the format specified.  With no epochtime, the
              current system date/time is used; optionally,  epochtime  may  be
              used  to  specify  the  number  of  seconds  since the epoch, and
              nanoseconds may additionally be used to  specify  the  number  of
              nanoseconds  past the second (otherwise that number is assumed to
              be 0).  See strftime(3) for  details.   The  zsh  extensions  de-
              scribed  in  the  section  EXPANSION  OF PROMPT SEQUENCES in zsh-
              misc(1) are also available.

              -n     Suppress printing a newline after the formatted string.

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

              -r     With the option -r (reverse), use format to parse the  in-
                     put  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 strp-
                     time(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 inter-
       faces, so the ztie builtin may move to a more generic module in the  fu-
       ture.

       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 syn-
              chronously 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 parame-
              ter  may  not  be  explicitly  unset,  so the only way to unset a
              global parameter created with `ztie -r' is to use `zuntie -u'.

       zgdbmpath parametername
              Put path to database file assigned to  parametername  into  REPLY
              scalar.

       zgdbm_tied
              Array holding names of all tied parameters.

       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  data-
       base on each reference.  Thus, for example, the values in a readonly ar-
       ray 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 occur-
              rence 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 ma-
       nipulation 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'.

       chmod [ -Rs ] mode filename ...
              Changes mode of files specified.

              The specified mode must be in octal.

              The  -R  option causes chmod to recursively descend into directo-
              ries, changing the mode of  all  files  in  the  directory  after
              changing the mode of the directory itself.

              The  -s option is a zsh extension to chmod functionality.  It en-
              ables paranoid behaviour, intended to avoid security problems in-
              volving a chmod being tricked into affecting files other than the
              ones intended.  It will refuse to follow symbolic links, so  that
              (for  example)  ``chmod  600 /tmp/foo/passwd'' can't accidentally
              chmod /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 chmod of a deep directory tree can't end up recursively
              chmoding /usr as a result of directories being moved up the tree.

       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 directo-
              ries, 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 en-
              ables paranoid behaviour, intended to avoid security problems in-
              volving 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  directo-
              ries.   This  check can be overridden using the -d option.  Typi-
              cally 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 compati-
              bility; either one indicates that if the target is a symlink then
              it should not be dereferenced.  Typically this is used in  combi-
              nation 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 di-
              rectories  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 cre-
              ated  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 speci-
              fied 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 ex-
              isting  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 [ -dfiRrs ] filename ...
              Removes files and directories specified.

              Normally, rm will not remove directories (except with the  -R  or
              -r options).  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 and -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 in-
              dications.  -f takes precedence.

              The -R and -r options cause rm to recursively descend into direc-
              tories, 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  recur-
              sively  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,  NO-
              EXPR,    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  re-
              sulting  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  ef-
              fect  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 direc-
              tory 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 el-
              ement with the  form  `array=("${(f@)mapfile[filename]}")'.   The
              double  quotes  and  the `@' are necessary to prevent empty lines
              from being removed.  Note that if the file ends with  a  newline,
              the  shell  will  split on the final newline, generating an addi-
              tional  empty  field;  this  can  be  suppressed  by  using  `ar-
              ray=("${(f@)${mapfile[filename]%$'\n'}}")'.

   Limitations
       Although reading and writing of the file in question is efficiently han-
       dled,  zsh's internal memory management may be arbitrarily baroque; how-
       ever, mapfile is usually very much more efficient than anything  involv-
       ing 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  particu-
       lar,  this  means  handling of sufficiently long files (greater than the
       machine's swap space, or than the range of the pointer type) will be in-
       correct.

       No errors are printed or flagged for non-existent,  unreadable,  or  un-
       writable  files, as the parameter mechanism is too low in the shell exe-
       cution 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, log2,
       logb, sin, sinh, sqrt, tan, tanh, y0, y1.  The atan function can option-
       ally take a second argument, in which case it behaves like the  C  func-
       tion  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  functions  min,  max, and sum are defined not in this module but in
       the zmathfunc autoloadable function, described in the section `Mathemat-
       ical Functions' in zshcontrib(1).

       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 inte-
       ger.  The functions float and int convert their arguments into a  float-
       ing 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 argu-
       ment.

       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/NEARCOLOR MODULE
       The zsh/nearcolor module replaces colours specified as hex triplets with
       the nearest colour in the 88 or 256 colour palettes that are widely used
       by  terminal emulators.  By default, 24-bit true colour escape codes are
       generated when colours are specified using hex triplets.  These are  not
       supported  by  all  terminals.  The purpose of this module is to make it
       easier to define colour preferences in a form that  can  work  across  a
       range of terminal emulators.

       Aside  from  the  default  colour, the ANSI standard for terminal escape
       codes provides for eight colours. The bright attribute  brings  this  to
       sixteen.  These basic colours are commonly used in terminal applications
       due to being widely supported. Expanded 88 and 256 colour  palettes  are
       also  common  and, while the first sixteen colours vary somewhat between
       terminals and configurations, these add a generally consistent and  pre-
       dictable set of colours.

       In  order  to  use the zsh/nearcolor module, it only needs to be loaded.
       Thereafter, whenever a colour is specified using a hex triplet, it  will
       be  compared  against each of the available colours and the closest will
       be selected. The first sixteen colours are never matched in this process
       due to being unpredictable.

       It isn't possible to reliably detect support for true colour in the ter-
       minal emulator. It is therefore recommended to be selective  in  loading
       the  zsh/nearcolor  module.  For  example, the following checks the COL-
       ORTERM environment variable:

              [[ $COLORTERM = *(24bit|truecolor)* ]] || zmodload zsh/nearcolor

       Note that some terminals accept the true color escape codes but map them
       internally to a  more  limited  palette  in  a  similar  manner  to  the
       zsh/nearcolor module.

THE ZSH/NEWUSER MODULE
       The zsh/newuser module is loaded at boot if it is available, the RCS op-
       tion 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/zsh/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 envi-
       ronment 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  di-
       rectories   can  be  configured  when  zsh  is  built  using  the  --en-
       able-site-scriptdir=dir and --enable-scriptdir=dir flags  to  configure,
       respectively;    the    defaults    are    prefix/share/zsh   and   pre-
       fix/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/zsh/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  func-
       tion is documented in the section `User Configuration Functions' in zsh-
       contrib(1).

THE ZSH/PARAMETER MODULE
       The  zsh/parameter  module gives access to some of the internal hash ta-
       bles 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 set-
              ting 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  in-
              voked.  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. Unset-
              ting a key removes the definition for the function named  by  the
              key.

       dis_functions
              Like functions but for disabled functions.

       functions_source
              This  readonly  associative array maps names of enabled functions
              to the name of the file containing the source of the function.

              For an autoloaded function  that  has  already  been  loaded,  or
              marked  for  autoload  with an absolute path, or that has had its
              path resolved with `functions -r', this is the file found for au-
              toloading, resolved to an absolute path.

              For a function defined within the body of  a  script  or  sourced
              file,  this  is the name of that file.  In this case, this is the
              exact path originally used to that file, which may be a  relative
              path.

              For  any  other function, including any defined at an interactive
              prompt or an autoload function whose path has not  yet  been  re-
              solved,  this  is the empty string.  However, the hash element is
              reported as defined just so long as the function is present:  the
              keys to this hash are the same as those to $functions.

       dis_functions_source
              Like functions_source but for disabled functions.

       builtins
              This associative array gives information about the  builtin  com-
              mands  currently  enabled.  The keys are the names of the builtin
              commands and the values are either `undefined' for  builtin  com-
              mands  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 parame-
              ters 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 di-
              rectory, the current working directory.

       history
              This  associative  array  maps  history event numbers to the full
              history lines.  Although it is presented as an associative array,
              the array of all values (${history[@]}) is guaranteed to  be  re-
              turned  in  order  from most recent to oldest history event, that
              is, by decreasing history event number.

       historywords
              A special array containing  the  words  stored  in  the  history.
              These also appear in most to least recent order.

       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.

              See  the  jobs  builtin  for how job information is provided in a
              subshell.

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

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

              See  the  jobs  builtin  for how job information is provided in a
              subshell.

       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 cur-
              rent 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.

              See  the  jobs  builtin  for how job information is provided in a
              subshell.

       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 file-
              name: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.  The source file name is resolved to an absolute path
              when the function is loaded or the path to it otherwise resolved.

              Most users will be interested in the information in the funcfile-
              trace array instead.

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

              The  standard  shell array zsh_eval_context can be used to deter-
              mine the type of shell construct being executed  at  each  depth:
              note,  however,  that is in the opposite order, with the most re-
              cent item last, and it is more detailed, for example including an
              entry for toplevel, the main shell code being executed either in-
              teractively 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.   Con-
              sequently,  the byte offset positions are only to be relied on in
              the context of using them for subsequent searches on string,  us-
              ing  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, in-
              stead use the -i switch of pcre_compile.

THE ZSH/PARAM/PRIVATE MODULE
       The zsh/param/private module is used to create parameters whose scope is
       limited to the current function body, and not to other functions  called
       by the current function.

       This module provides a single autoloaded builtin:

       private [ {+|-}AHUahlmrtux ] [ {+|-}EFLRZi [ n ] ] [ name[=value] ... ]
              The private builtin accepts all the same options and arguments as
              local  (zshbuiltins(1)) except for the `-T' option.  Tied parame-
              ters may not be made private.

              The `-p' option is presently a no-op because the state of private
              parameters cannot reliably be reloaded.   This  also  applies  to
              printing private parameters with `typeset -p'.

              If used at the top level (outside a function scope), private cre-
              ates a normal parameter in the same manner as declare or typeset.
              A  warning  about  this  is  printed if WARN_CREATE_GLOBAL is set
              (zshoptions(1)).  Used inside a function scope, private creates a
              local parameter similar to one declared with local, except having
              special properties noted below.

              Special parameters which  expose  or  manipulate  internal  shell
              state,  such  as  ARGC,  argv,  COLUMNS,  LINES,  UID, EUID, IFS,
              PROMPT, RANDOM, SECONDS, etc., cannot be made private unless  the
              `-h' option is used to hide the special meaning of the parameter.
              This may change in the future.

       As  with  other typeset equivalents, private is both a builtin and a re-
       served word, so arrays may be  assigned  with  parenthesized  word  list
       name=(value...)  syntax.   However,  the  reserved word `private' is not
       available until zsh/param/private is loaded, so care must be taken  with
       order  of  execution and parsing for function definitions which use pri-
       vate.  To compensate for this, the module also adds the option  `-P'  to
       the `local' builtin to declare private parameters.

       For  example,  this  construction fails if zsh/param/private has not yet
       been loaded when `bad_declaration' is defined:
              bad_declaration() {
                zmodload zsh/param/private
                private array=( one two three )
              }

       This construction works because local is already a keyword, and the mod-
       ule is loaded before the statement is executed:
              good_declaration() {
                zmodload zsh/param/private
                local -P array=( one two three )
              }

       The following is usable in scripts but may have trouble with autoload:
              zmodload zsh/param/private
              iffy_declaration() {
                private array=( one two three )
              }

       The private builtin may always be used with scalar assignments  and  for
       declarations without assignments.

       Parameters declared with private have the following properties:

       •      Within  the function body where it is declared, the parameter be-
              haves as a local, except as noted above for tied or special para-
              meters.

       •      The type of a parameter declared private cannot be changed in the
              scope where it was declared, even  if  the  parameter  is  unset.
              Thus an array cannot be assigned to a private scalar, etc.

       •      Within  any  other function called by the declaring function, the
              private parameter does NOT hide  other  parameters  of  the  same
              name, so for example a global parameter of the same name is visi-
              ble  and may be assigned or unset.  This includes calls to anony-
              mous functions, although that may  also  change  in  the  future.
              However,  the  private  name may not be created outside the local
              scope when it was not previously declared.

       •      An exported private remains in the environment  of  inner  scopes
              but  appears unset for the current shell in those scopes.  Gener-
              ally, exporting private parameters should be avoided.

       Note that this differs from the static scope defined  by  compiled  lan-
       guages  derived from C, in that the a new call to the same function cre-
       ates a new scope, i.e., the parameter is still associated with the  call
       stack  rather  than  with  the function definition.  It differs from ksh
       `typeset -S' because the syntax used to define the function has no bear-
       ing on whether the parameter scope is respected.

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 paren-
              theses within the regex, then the match array variable will  con-
              tain  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.

              Note  that  the zsh/regex module logic relies on the host system.
              The same expr and regex pair could produce different  results  on
              different platforms if a regex with non-standard syntax is given.

              For example, no syntax for matching a word boundary is defined in
              the  POSIX extended regular expression standard. GNU libc and BSD
              libc  both  provide  such  syntaxes   as   extensions   (\b   and
              [[:<:]]/[[:>:]]  respectively),  but neither of these syntaxes is
              supported by both of these implementations.

              Refer to the regcomp(3) and re_format(7)  manual  pages  on  your
              system for locally-supported syntax.

THE ZSH/SCHED MODULE
       The zsh/sched module makes available one builtin command and one parame-
       ter.

       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 lat-
              ter 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 emula-
              tor's title bar.

              To effect changes to the editor buffer when  an  event  executes,
              use  the `zle' command with no arguments to test whether the edi-
              tor is active, and if it is, then use `zle widget' to access  the
              editor via the named widget.

              The sched builtin is not made available by default when the shell
              starts  in a mode emulating another shell.  It can be made avail-
              able 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 num-
              bers 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 parame-
              ter 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.

              File  descriptors  can be closed with normal shell syntax when no
              longer needed, for example:

                     exec {REPLY}>&-

   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.  The file descriptor  remains  open  in  sub-
              shells and forked external executables.

              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 asso-
              ciated  with  listenfd.  The shell parameter REPLY will be set to
              the file descriptor associated with the inbound connection.   The
              file descriptor remains open in subshells and forked external ex-
              ecutables.

              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 possi-
       ble 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 ele-
              ment `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' num-
                     ber).

              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  pre-
              ceded  by  a `+' in the option list; only one element is allowed.
              The element may be shortened to any unique set of leading charac-
              ters.  Otherwise, all elements will be shown for all files.

              Options:

              -A array
                     Instead of displaying the results on standard output,  as-
                     sign  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,  respec-
                     tively.   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 preced-
                     ing all the others.   Other  formatting  options  are  re-
                     spected.

              -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  for-
                     matting  of the time elements.  The format string supports
                     all of the zsh extensions described in the section  EXPAN-
                     SION OF PROMPT SEQUENCES in zshmisc(1).  In particular, -F
                     %s.%N  can be used to show timestamps with nanosecond pre-
                     cision if supported by the system.  The -s option  is  im-
                     plied.

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

              -l     List the names of the type elements (to standard output or
                     an array as appropriate)  and  return  immediately;  argu-
                     ments, and options other than -A, 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 re-
                     turned.  This option is required to make the link  element
                     useful.  It's important to note that this is the exact op-
                     posite 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 dec-
                     imal.  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  op-
                     tions, 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 se-
                     lected.

              -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 para-
       meters.

   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  er-
              ror 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 er-
              ror in the parameters, and a return status of 2 indicates the er-
              ror 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 ap-
              pending, respectively. The -m option allows the  initial  permis-
              sions  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 as-
              signed.

              The -o option allows various system specific options to be speci-
              fied as a comma-separated list. The following is a list of possi-
              ble  options. Note that, depending on the system, some may not be
              available.
              cloexec
                     mark file to be closed when other  programs  are  executed
                     (else  the  file  descriptor remains open in subshells and
                     forked external executables)

              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

              nonblock
                     the file is opened in nonblocking mode

              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 stan-
                     dard 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  writ-
                     ing them to outfd.  The parameter ERRNO gives the error.

              4      The attempt to read timed out.  Note this does not set ER-
                     RNO 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 ac-
                     cording to the usual rules;  no  write  to  outfd  is  at-
                     tempted.

       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 de-
              scriptor 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  out-
              put, 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 pa-
              rameters 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 ] [ -i interval ] [ -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 conve-
              nient to create file locks within subshells, since  the  lock  is
              automatically released when the subshell exits.  Note that use of
              the  print builtin with the -u option will, as a side effect, re-
              lease the lock, as will redirection to  the  file  in  the  shell
              holding  the  lock.   To  work  around  this use a subshell, e.g.
              `(print message) >> file'.  Status 0 is returned if the lock suc-
              ceeds, else status 1.

              In the second form the file descriptor given  by  the  arithmetic
              expression  fd_expr  is  closed,  releasing a lock.  The file de-
              scriptor 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 us-
              ing  `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 sec-
              onds; fractional seconds are allowed.  During  this  period,  the
              shell will attempt to lock the file every interval seconds if the
              -i  interval option is given, otherwise once a second.  (This in-
              terval is shortened before the last attempt if  needed,  so  that
              the  shell  waits only until the timeout and not longer.)  If the
              attempt times out, status 2 is returned.

              (Note: timeout is limited to 2^30-1 seconds (about 34 years), and
              interval to 0.999 * LONG_MAX microseconds (only about 35  minutes
              on 32-bit systems).)

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

              If the option -r is given, the lock is only for  reading,  other-
              wise  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 re-
              turned.  Status 1 can indicate one of two things:  subcommand  is
              known  but not supported by the current operating system, or sub-
              command 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 num-
              bers 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  current process ID of the parent of the cur-
                     rent process, even in subshells.  Compare $PPID, which re-
                     turns the process ID of the initial  parent  of  the  main
                     shell process.

              procsubstpid
                     Returns  the  process  ID  of the last process started for
                     process substitution, i.e. the <(...)  and  >(...)  expan-
                     sions.

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 com-
              mand 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  ad-
                     dress 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 ad-
                     dress 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  connec-
       tion.

       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/WATCH MODULE
       The zsh/watch module can be used to report when specific users log in or
       out. This is controlled via the following parameters.

       LOGCHECK
              The interval in seconds between checks for login/logout  activity
              using the watch parameter.

       watch <S> <Z> (WATCH <S>)
              An array (colon-separated list) of login/logout events to report.

              If  it  contains  the  single  word  `all', then all login/logout
              events are reported.  If it contains  the  single  word  `notme',
              then all events are reported as with `all' except $USERNAME.

              An  entry in this list may consist of a username, an `@' followed
              by a remote hostname, and a `%' followed by a line (tty).  Any of
              these may be a pattern (be sure to quote this during the  assign-
              ment to watch so that it does not immediately perform file gener-
              ation);  the  setting  of  the EXTENDED_GLOB option is respected.
              Any or all of these components may be present in an entry;  if  a
              login/logout event matches all of them, it is reported.

              For example, with the EXTENDED_GLOB option set, the following:

                     watch=('^(pws|barts)')

              causes  reports  for activity associated with any user other than
              pws or barts.

       WATCHFMT
              The format of login/logout reports if the watch parameter is set.
              Default is `%n has %a %l from %m'.  Recognizes the following  es-
              cape sequences:

              %n     The name of the user that logged in/out.

              %a     The observed action, i.e. "logged on" or "logged off".

              %l     The line (tty) the user is logged in on.

              %M     The full hostname of the remote host.

              %m     The  hostname up to the first `.'.  If only the IP address
                     is available or the utmp field contains  the  name  of  an
                     X-windows display, the whole name is printed.

                     NOTE: The `%m' and `%M' escapes will work only if there is
                     a  host name field in the utmp on your machine.  Otherwise
                     they are treated as ordinary strings.

              %F{color} (%f)
                     Start (stop) using a different foreground color.

              %K{color} (%k)
                     Start (stop) using a different background color.

              %S (%s)
                     Start (stop) standout mode.

              %U (%u)
                     Start (stop) underline mode.

              %B (%b)
                     Start (stop) boldface mode.

              %t
              %@     The time, in 12-hour, am/pm format.

              %T     The time, in 24-hour format.

              %w     The date in `day-dd' format.

              %W     The date in `mm/dd/yy' format.

              %D     The date in `yy-mm-dd' format.

              %D{string}
                     The date formatted as string using the strftime  function,
                     with  zsh  extensions  as described by EXPANSION OF PROMPT
                     SEQUENCES in zshmisc(1).

              %(x:true-text:false-text)
                     Specifies a ternary expression.  The  character  following
                     the x is arbitrary; the same character is used to separate
                     the  text  for the "true" result from that for the "false"
                     result.  Both the separator and the right parenthesis  may
                     be  escaped  with a backslash.  Ternary expressions may be
                     nested.

                     The test character x may be any one of `l',  `n',  `m'  or
                     `M',  which  indicate a `true' result if the corresponding
                     escape sequence would return a non-empty value; or it  may
                     be  `a',  which  indicates  a `true' result if the watched
                     user has logged in, or  `false'  if  he  has  logged  out.
                     Other  characters  evaluate to neither true nor false; the
                     entire expression is omitted in this case.

                     If the result is `true', then the true-text  is  formatted
                     according   to  the  rules  above  and  printed,  and  the
                     false-text is  skipped.   If  `false',  the  true-text  is
                     skipped  and the false-text is formatted and printed.  Ei-
                     ther or both of the branches may be empty, but both  sepa-
                     rators must be present in any case.

       Furthermore, the zsh/watch module makes available one builtin command:

       log    List  all  users currently logged in who are affected by the cur-
              rent setting of the watch parameter.

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  in-
              terface;  a  set is provided with the zsh distribution and is de-
              scribed 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 au-
              tomatically 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 in-
              put 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_AC-
              COUNT 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 argu-
              ments.   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  other-
              wise.

              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 lo-
              gin  subcommand,  including special handling of password.  If the
              `?' is followed by a string, that is used as the prompt for read-
              ing 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  sys-
              tems.

       dir [ arg ... ]
              Give  a  (verbose) listing of the remote directory.  The args are
              passed directly to the server. The command's behaviour is  imple-
              mentation  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 out-
              put.

       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 over-
              head.

       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  for-
              mat 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 informa-
              tion.   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  descrip-
              tor 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 send-
              ing 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 behav-
              iour 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 do-
              ing this.  Useful commands may include STAT and HELP.  Note  also
              the  mechanism  for returning messages as described for the vari-
              able 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 parame-
              ters  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 argu-
              ment, 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  exist-
              ing  session  becomes the new current session, otherwise the cur-
              rent 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 nota-
              tion.

       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 connec-
              tion  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  appro-
              priate  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 re-
              sponse to an FTP SYST request.  The most interesting  case  is  a
              string  beginning "UNIX Type: L8", which ensures maximum compati-
              bility 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  descrip-
              tion 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 de-
              fined:

              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  cor-
              respond 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 in-
              terpretation 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 stan-
              dard output, so it is vital that this function  should  write  to
              standard  error or directly to the terminal, not to standard out-
              put.

              When it is called with a transfer in progress, the following  ad-
              ditional 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 al-
                     ways available.

              The function is initially called with ZFTP_TRANSFER set appropri-
              ately and ZFTP_COUNT set to zero.  After  the  transfer  is  fin-
              ished, the function will be called one more time with ZFTP_TRANS-
              FER  set to GF or PF, in case it wishes to tidy up.  It is other-
              wise 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  harm-
       less).

       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  order-
       ing 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 zsh-
       zle(1)).

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

       widgets
              This associative array contains one entry per widget. 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,
                a string of the form `completion:type:name'
                  for completion widgets,
                or a null value if the widget is not yet fully defined.  In the
              penultimate case, type is the name of the builtin widget the com-
              pletion  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 num-
              ber 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 aver-
              age time in milliseconds spent in the function  and  its  descen-
              dants  per  call  and  the  percentage of time spent in all shell
              functions used in this function and its descendants.  The follow-
              ing 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 func-
              tions 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 func-
              tion at the beginning and have their function named  indented  to
              make  it  easier to distinguish the line showing the function de-
              scribed 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 invoca-
              tions 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  be-
              tween,  then  executed  as  a  command,  as if passed to the eval
              builtin.  The command runs under a newly  assigned  pseudo-termi-
              nal;  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 ter-
              minal to be monitored with  ZLE  descriptor  handlers  (see  zsh-
              zle(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.  The exact input  is  always
              copied: the -n option is not applied.

              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 stan-
              dard 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  sta-
              tus 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  com-
              mands 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  system's  documentation  for  se-
              lect(3).   Note  there is no connection with the shell builtin of
              the same name.

              Arguments and options may be intermingled in any order.   Non-op-
              tion  arguments are file descriptors, which must be decimal inte-
              gers.  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 un-
              likely 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 indi-
              cate  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  re-
              quested 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 [ metapattern [ 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
              matched against the patterns.  The definition stored for the most
              specific pattern that matches will be returned.

              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 com-
              plex patterns are considered to be more specific than the pattern
              `*'.   A `*' in the pattern will match zero or more characters in
              the context; colons are not treated specially in this regard.  If
              two patterns are equally specific, the tie is broken in favour of
              the pattern that was defined first.

              Example

              For example, a fictional `weather' plugin might state in its doc-
              umentation that it looks up the preferred-precipitation style un-
              der  the   `:weather:continent:day-of-the-week:phase-of-the-moon'
              context.   According to this, you might set the following in your
              zshrc:

                     zstyle ':weather:europe:*' preferred-precipitation rain
                     zstyle ':weather:*:Sunday:*' preferred-precipitation snow

              Then the plugin would run under the hood a command such as

                     zstyle -s ":weather:${continent}:${day_of_week}:${moon_phase}" preferred-precipitation REPLY

              in order to retrieve your preference  into  the  scalar  variable
              $REPLY.   On  Sundays $REPLY would be set to `snow'; in Europe it
              would be set to `rain'; and on Sundays in Europe it would be  set
              to  `snow'  again,  because  the patterns `:weather:europe:*' and
              `:weather:*:Sunday:*' both match the context argument  to  zstyle
              -s,  are  equally  specific, and the latter is more specific (be-
              cause it has more colon-separated components).

              Usage

              The forms that operate on patterns are the following.

              zstyle [ -L [ metapattern [ style ] ] ]
                     Without arguments, lists style  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, metapat-
                     tern, is a pattern  which  will  be  matched  against  the
                     string  supplied  as  pattern  when the style was defined.
                     Note: 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.

              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 evalu-
                     ating 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  defini-
                     tions 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 styles for a given
              context.

              zstyle -s context style name [ sep ]
                     The parameter name is set to the value of the style inter-
                     preted 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.

                     Return 0 if the style is set, 1 otherwise.

              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'.

                     Return 0 if name is set to `yes', 1 otherwise.

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

                     Return 0 if the style is set, 1 otherwise.

              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 sta-
                     tus 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 -F param format spec ...
       zformat -a array sep spec ...
              This builtin provides 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  re-
              sulting 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  de-
              limiter  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 expres-
              sion, and compared with the test number.  If they are  the  same,
              text1  is output, else text2 is output.  A parenthesis may be es-
              caped 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.

              With  -F  instead  of  -f, ternary expressions choose between the
              `true' or `false' text on the basis of whether the format  speci-
              fier is present and non-empty.  A test number indicates a minimum
              width  for the value given in the format specifier. Negative num-
              bers reverse this, so the test is for whether the value exceeds a
              maximum width.

              The 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 re-
              placing 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.  A colon in the left string can be es-
              caped with a backslash.  The resulting strings are stored in  the
              array.

       zregexparse
              This implements some internals of the _regex_arguments function.

       zparseopts [ -D -E -F -K -M ] [ -a array ] [ -A assoc ] [ - ] spec ...
              This  builtin simplifies the parsing of options in positional pa-
              rameters, i.e. the set of arguments given by $*.  Each  spec  de-
              scribes  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 op-
              tional  `=array'  is given, it is instead copied into that array,
              which should be declared as a normal array and never as an  asso-
              ciative array.

              Note that it is an error to give any spec without an `=array' un-
              less 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 `--'. See
              also -F.

              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 ar-
                     ray 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  argu-
                     ment,  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 argu-
                     ment; 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 ar-
                     guments 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.

              In all cases, option-arguments  must  appear  either  immediately
              following  the  option in the same positional parameter or in the
              next one. Even an optional argument may appear in the next  para-
              meter, unless it begins with a `-'.  There is no special handling
              of  `='  as  with  GNU-style  argument  parsers;  given  the spec
              `-foo:',  the  positional  parameter  `--foo=bar'  is  parsed  as
              `--foo' with an argument of `=bar'.

              When the names of two options that take no arguments overlap, the
              longest  one  wins,  so that parsing for the specs `-foo -foobar'
              (for example) is unambiguous. However, due to the  aforementioned
              handling of option-arguments, ambiguities may arise when at least
              one overlapping spec takes an argument, as in `-foo: -foobar'. In
              that case, the last matching spec wins.

              The  options  of zparseopts itself cannot be stacked because, for
              example, the stack `-DEK' is indistinguishable from  a  spec  for
              the GNU-style long option `--DEK'.  The options of zparseopts it-
              self 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.  If the first such parameter is `-' or `--',
                     it is removed as well.  This is similar to using the shift
                     builtin.

              -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.
                     As indicated above, parsing still stops at the  first  `-'
                     or  `--'  not  described  by a spec, but it is not removed
                     when used with -D.

              -F     If this option is given, zparseopts immediately  stops  at
                     the  first  option-like  parameter not described by one of
                     the specs, prints an error message, and returns status  1.
                     Removal  (-D)  and  extraction (-E) are not performed, and
                     option arrays are not updated.  This provides basic  vali-
                     dation for the given options.

                     Note  that  the appearance in the positional parameters of
                     an option without  its  required  argument  always  aborts
                     parsing and returns an error as described above regardless
                     of whether this option is used.

              -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 el-
                     ements  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  an-
                     other  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 unpre-
                     dictable if the `name+' specifier is used inconsistently.

              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  posi-
              tional 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)

zsh 5.9                           May 14, 2022                    ZSHMODULES(1)

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