Provided by: zsh-common_5.9-5ubuntu1_all bug

NAME

       zshoptions - zsh options

SPECIFYING OPTIONS

       Options  are  primarily  referred  to  by  name.   These  names  are  case insensitive and
       underscores are ignored.  For example, `allexport' is equivalent to `A__lleXP_ort'.

       The sense of an option name may be inverted by preceding it with `no', so `setopt No_Beep'
       is  equivalent to `unsetopt beep'.  This inversion can only be done once, so `nonobeep' is
       not a synonym for `beep'.   Similarly,  `tify'  is  not  a  synonym  for  `nonotify'  (the
       inversion of `notify').

       Some  options  also  have  one  or more single letter names.  There are two sets of single
       letter options: one used by default, and another used to emulate  sh/ksh  (used  when  the
       SH_OPTION_LETTERS  option  is  set).   The  single letter options can be used on the shell
       command line, or with the set, setopt  and  unsetopt  builtins,  as  normal  Unix  options
       preceded by `-'.

       The  sense of the single letter options may be inverted by using `+' instead of `-'.  Some
       of the single letter option names refer  to  an  option  being  off,  in  which  case  the
       inversion of that name refers to the option being on.  For example, `+n' is the short name
       of `exec', and `-n' is the short name of its inversion, `noexec'.

       In strings of single letter options supplied to the shell at startup, trailing  whitespace
       will  be  ignored;  for  example the string `-f    ' will be treated just as `-f', but the
       string `-f i' is an error.   This  is  because  many  systems  which  implement  the  `#!'
       mechanism for calling scripts do not strip trailing whitespace.

       It  is possible for options to be set within a function scope.  See the description of the
       option LOCAL_OPTIONS below.

DESCRIPTION OF OPTIONS

       In the following list, options set by default in all emulations are marked <D>; those  set
       by  default  only  in  csh,  ksh,  sh,  or zsh emulations are marked <C>, <K>, <S>, <Z> as
       appropriate.  When listing options (by `setopt', `unsetopt', `set -o' or `set +o'),  those
       turned   on   by   default   appear  in  the  list  prefixed  with  `no'.   Hence  (unless
       KSH_OPTION_PRINT is set), `setopt' shows all options whose settings are changed  from  the
       default.

   Changing Directories
       AUTO_CD (-J)
              If  a command is issued that can't be executed as a normal command, and the command
              is the name of a directory, perform the cd command to that directory.  This  option
              is only applicable if the option SHIN_STDIN is set, i.e. if commands are being read
              from standard input.  The option is designed for interactive use; it is recommended
              that cd be used explicitly in scripts to avoid ambiguity.

       AUTO_PUSHD (-N)
              Make cd push the old directory onto the directory stack.

       CDABLE_VARS (-T)
              If  the  argument to a cd command (or an implied cd with the AUTO_CD option set) is
              not a directory, and does not begin with a slash, try to expand the  expression  as
              if it were preceded by a `~' (see the section `Filename Expansion').

       CD_SILENT
              Never  print the working directory after a cd (whether explicit or implied with the
              AUTO_CD option set). cd normally prints the working  directory  when  the  argument
              given  to  it  was -, a stack entry, or the name of a directory found under CDPATH.
              Note that  this  is  distinct  from  pushd's  stack-printing  behaviour,  which  is
              controlled  by  PUSHD_SILENT. This option overrides the printing-related effects of
              POSIX_CD.

       CHASE_DOTS
              When changing to a directory containing a path segment `..' which  would  otherwise
              be  treated as canceling the previous segment in the path (in other words, `foo/..'
              would be removed from the path, or if `..' is the first part of the path, the  last
              part  of  the current working directory would be removed), instead resolve the path
              to the physical directory.  This option is overridden by CHASE_LINKS.

              For example, suppose /foo/bar is a link to the directory  /alt/rod.   Without  this
              option set, `cd /foo/bar/..' changes to /foo; with it set, it changes to /alt.  The
              same applies if the current directory is /foo/bar and `cd ..' is used.   Note  that
              all other symbolic links in the path will also be resolved.

       CHASE_LINKS (-w)
              Resolve symbolic links to their true values when changing directory.  This also has
              the effect of CHASE_DOTS, i.e. a `..' path segment will be treated as referring  to
              the physical parent, even if the preceding path segment is a symbolic link.

       POSIX_CD <K> <S>
              Modifies the behaviour of cd, chdir and pushd commands to make them more compatible
              with the POSIX standard. The behaviour with the option unset is  described  in  the
              documentation  for  the  cd  builtin  in zshbuiltins(1).  If the option is set, the
              shell does not test for directories beneath the local directory (`.')  until  after
              all  directories  in  cdpath have been tested, and the cd and chdir commands do not
              recognise arguments of the form `{+|-}n' as directory stack entries.

              Also, if the option is set, the conditions under which the  shell  prints  the  new
              directory  after  changing  to  it  are  modified.   It  is no longer restricted to
              interactive shells (although printing of the directory stack with  pushd  is  still
              limited  to  interactive shells); and any use of a component of CDPATH, including a
              `.' but excluding an empty component that is otherwise treated as `.',  causes  the
              directory to be printed.

       PUSHD_IGNORE_DUPS
              Don't push multiple copies of the same directory onto the directory stack.

       PUSHD_MINUS
              Exchanges  the  meanings  of  `+'  and  `-'  when  used  with a number to specify a
              directory in the stack.

       PUSHD_SILENT (-E)
              Do not print the directory stack after pushd or popd.

       PUSHD_TO_HOME (-D)
              Have pushd with no arguments act like `pushd $HOME'.

   Completion
       ALWAYS_LAST_PROMPT <D>
              If unset, key functions that list completions try to return to the last  prompt  if
              given  a  numeric argument. If set these functions try to return to the last prompt
              if given no numeric argument.

       ALWAYS_TO_END
              If a completion is performed with the cursor within a word, and a  full  completion
              is  inserted,  the  cursor is moved to the end of the word.  That is, the cursor is
              moved to the end of the  word  if  either  a  single  match  is  inserted  or  menu
              completion is performed.

       AUTO_LIST (-9) <D>
              Automatically list choices on an ambiguous completion.

       AUTO_MENU <D>
              Automatically  use  menu  completion  after  the  second  consecutive  request  for
              completion, for example  by  pressing  the  tab  key  repeatedly.  This  option  is
              overridden by MENU_COMPLETE.

       AUTO_NAME_DIRS
              Any parameter that is set to the absolute name of a directory immediately becomes a
              name for that directory,  that  will  be  used  by  the  `%~'  and  related  prompt
              sequences,  and  will  be available when completion is performed on a word starting
              with `~'.  (Otherwise, the parameter must be used in the form `~param' first.)

       AUTO_PARAM_KEYS <D>
              If a parameter name was completed and a  following  character  (normally  a  space)
              automatically  inserted,  and the next character typed is one of those that have to
              come directly after the  name  (like  `}',  `:',  etc.),  the  automatically  added
              character  is  deleted,  so  that  the  character typed comes immediately after the
              parameter name.  Completion in a brace expansion is affected similarly:  the  added
              character is a `,', which will be removed if `}' is typed next.

       AUTO_PARAM_SLASH <D>
              If  a  parameter  is completed whose content is the name of a directory, then add a
              trailing slash instead of a space.

       AUTO_REMOVE_SLASH <D>
              When the last character resulting from  a  completion  is  a  slash  and  the  next
              character  typed  is  a word delimiter, a slash, or a character that ends a command
              (such as a semicolon or an ampersand), remove the slash.

       BASH_AUTO_LIST
              On an ambiguous completion, automatically list choices when the completion function
              is  called twice in succession.  This takes precedence over AUTO_LIST.  The setting
              of LIST_AMBIGUOUS is respected.  If AUTO_MENU is set, the menu behaviour will  then
              start with the third press.  Note that this will not work with MENU_COMPLETE, since
              repeated completion calls immediately cycle through the list in that case.

       COMPLETE_ALIASES
              Prevents aliases on the command  line  from  being  internally  substituted  before
              completion  is  attempted.   The effect is to make the alias a distinct command for
              completion purposes.

       COMPLETE_IN_WORD
              If unset, the cursor is set to the end  of  the  word  if  completion  is  started.
              Otherwise it stays there and completion is done from both ends.

       GLOB_COMPLETE
              When  the  current  word  has a glob pattern, do not insert all the words resulting
              from the expansion but generate matches as for completion and  cycle  through  them
              like  MENU_COMPLETE.  The matches are generated as if a `*' was added to the end of
              the word, or inserted at the cursor when COMPLETE_IN_WORD is  set.   This  actually
              uses  pattern  matching,  not  globbing, so it works not only for files but for any
              completion, such as options, user names, etc.

              Note that when  the  pattern  matcher  is  used,  matching  control  (for  example,
              case-insensitive  or  anchored  matching)  cannot  be  used.   This limitation only
              applies  when  the  current  word  contains  a  pattern;  simply  turning  on   the
              GLOB_COMPLETE option does not have this effect.

       HASH_LIST_ALL <D>
              Whenever  a  command  completion or spelling correction is attempted, make sure the
              entire command path is hashed first.  This makes the first  completion  slower  but
              avoids false reports of spelling errors.

       LIST_AMBIGUOUS <D>
              This  option  works  when  AUTO_LIST or BASH_AUTO_LIST is also set.  If there is an
              unambiguous prefix to insert on the command line, that is done without a completion
              list  being displayed; in other words, auto-listing behaviour only takes place when
              nothing would be inserted.  In the case of BASH_AUTO_LIST, this means that the list
              will be delayed to the third call of the function.

       LIST_BEEP <D>
              Beep  on  an  ambiguous  completion.   More  accurately, this forces the completion
              widgets to return status 1 on an ambiguous completion, which causes  the  shell  to
              beep  if  the option BEEP is also set; this may be modified if completion is called
              from a user-defined widget.

       LIST_PACKED
              Try to make the completion list smaller (occupying  less  lines)  by  printing  the
              matches in columns with different widths.

       LIST_ROWS_FIRST
              Lay  out  the  matches in completion lists sorted horizontally, that is, the second
              match is to the right of the first one, not under it as usual.

       LIST_TYPES (-X) <D>
              When listing files that are possible completions, show the type of each file with a
              trailing identifying mark.

       MENU_COMPLETE (-Y)
              On an ambiguous completion, instead of listing possibilities or beeping, insert the
              first match immediately.  Then when completion is requested again, remove the first
              match and insert the second match, etc.  When there are no more matches, go back to
              the first one again.  reverse-menu-complete may be used to loop through the list in
              the other direction. This option overrides AUTO_MENU.

       REC_EXACT (-S)
              If  the string on the command line exactly matches one of the possible completions,
              it is accepted, even  if  there  is  another  completion  (i.e.  that  string  with
              something else added) that also matches.

   Expansion and Globbing
       BAD_PATTERN (+2) <C> <Z>
              If  a pattern for filename generation is badly formed, print an error message.  (If
              this option is unset, the pattern will be left unchanged.)

       BARE_GLOB_QUAL <Z>
              In a glob pattern, treat a trailing set of parentheses as a qualifier list,  if  it
              contains  no  `|',  `('  or (if special) `~' characters.  See the section `Filename
              Generation'.

       BRACE_CCL
              Expand expressions in braces which would not otherwise undergo brace expansion to a
              lexically ordered list of all the characters.  See the section `Brace Expansion'.

       CASE_GLOB <D>
              Make  globbing  (filename  generation)  sensitive to case.  Note that other uses of
              patterns are always sensitive to case.  If the option is unset, the presence of any
              character  which  is  special  to  filename  generation will cause case-insensitive
              matching.  For example, cvs(/) can match the directory CVS owing to the presence of
              the globbing flag (unless the option BARE_GLOB_QUAL is unset).

       CASE_MATCH <D>
              Make  regular  expressions  using  the zsh/regex module (including matches with =~)
              sensitive to case.

       CASE_PATHS
              If CASE_PATHS is not set (the default), CASE_GLOB  affects  the  interpretation  of
              every  path component, whenever a special character appears in any component.  When
              CASE_PATHS is set, file path  components  that  do  not  contain  special  filename
              generation  characters  are always sensitive to case, thus restricting NO_CASE_GLOB
              to components that contain globbing characters.

              Note that if the filesystem itself is not sensitive to case, then CASE_PATHS has no
              effect.

       CSH_NULL_GLOB <C>
              If  a  pattern  for filename generation has no matches, delete the pattern from the
              argument list; do not report an error unless all the patterns in a command have  no
              matches.  Overrides NOMATCH.

       EQUALS <Z>
              Perform = filename expansion.  (See the section `Filename Expansion'.)

       EXTENDED_GLOB
              Treat  the `#', `~' and `^' characters as part of patterns for filename generation,
              etc.  (An initial unquoted `~' always produces named directory expansion.)

       FORCE_FLOAT
              Constants in arithmetic evaluation will be treated as floating point  even  without
              the  use  of  a decimal point; the values of integer variables will be converted to
              floating point when used in arithmetic expressions.  Integers in any base  will  be
              converted.

       GLOB (+F, ksh: +f) <D>
              Perform filename generation (globbing).  (See the section `Filename Generation'.)

       GLOB_ASSIGN <C>
              If  this  option  is  set, filename generation (globbing) is performed on the right
              hand side of scalar parameter assignments of the form `name=pattern (e.g. `foo=*').
              If  the result has more than one word the parameter will become an array with those
              words as arguments. This option  is  provided  for  backwards  compatibility  only:
              globbing  is  always  performed  on the right hand side of array assignments of the
              form `name=(value)' (e.g. `foo=(*)') and this form is recommended for clarity; with
              this  option set, it is not possible to predict whether the result will be an array
              or a scalar.

       GLOB_DOTS (-4)
              Do not require a leading `.' in a filename to be matched explicitly.

       GLOB_STAR_SHORT
              When this option is set and the  default  zsh-style  globbing  is  in  effect,  the
              pattern  `**/*'  can  be  abbreviated  to  `**'  and  the  pattern  `***/*'  can be
              abbreviated to ***.  Hence `**.c' finds a file ending in .c  in  any  subdirectory,
              and  `***.c'  does  the  same while also following symbolic links.  A / immediately
              after the `**' or `***' forces the pattern to be treated as the unabbreviated form.

       GLOB_SUBST <C> <K> <S>
              Treat any characters resulting from  parameter  expansion  as  being  eligible  for
              filename  expansion  and  filename  generation,  and  any characters resulting from
              command substitution as being eligible for filename generation.  Braces (and commas
              in between) do not become eligible for expansion.

       HIST_SUBST_PATTERN
              Substitutions  using  the  :s  and  :& history modifiers are performed with pattern
              matching instead of string matching.  This occurs wherever  history  modifiers  are
              valid,  including  glob  qualifiers and parameters.  See the section `Modifiers' in
              zshexpn(1).

       IGNORE_BRACES (-I) <S>
              Do not perform brace expansion.  For historical  reasons  this  also  includes  the
              effect of the IGNORE_CLOSE_BRACES option.

       IGNORE_CLOSE_BRACES
              When neither this option nor IGNORE_BRACES is set, a sole close brace character `}'
              is syntactically significant at any point on a command line.  This has  the  effect
              that  no  semicolon or newline is necessary before the brace terminating a function
              or current shell construct.   When  either  option  is  set,  a  closing  brace  is
              syntactically  significant  only  in  command position.  Unlike IGNORE_BRACES, this
              option does not disable brace expansion.

              For example, with both options unset a function may be  defined  in  the  following
              fashion:

                     args() { echo $# }

              while  if  either option is set, this does not work and something equivalent to the
              following is required:

                     args() { echo $#; }

       KSH_GLOB <K>
              In pattern matching, the interpretation of parentheses is affected by  a  preceding
              `@', `*', `+', `?' or `!'.  See the section `Filename Generation'.

       MAGIC_EQUAL_SUBST
              All  unquoted  arguments  of  the  form  `anything=expression'  appearing after the
              command name have filename expansion (that is, where expression has a  leading  `~'
              or `=') performed on expression as if it were a parameter assignment.  The argument
              is not otherwise treated specially; it  is  passed  to  the  command  as  a  single
              argument,  and  not  used  as an actual parameter assignment.  For example, in echo
              foo=~/bar:~/rod, both occurrences of ~ would be replaced.  Note that  this  happens
              anyway with typeset and similar statements.

              This  option  respects  the  setting of the KSH_TYPESET option.  In other words, if
              both options are in effect, arguments looking like  assignments  will  not  undergo
              word splitting.

       MARK_DIRS (-8, ksh: -X)
              Append  a  trailing  `/'  to all directory names resulting from filename generation
              (globbing).

       MULTIBYTE <D>
              Respect multibyte characters when found in  strings.   When  this  option  is  set,
              strings  are  examined  using the system library to determine how many bytes form a
              character, depending on the current locale.  This affects the  way  characters  are
              counted in pattern matching, parameter values and various delimiters.

              The  option  is  on  by  default  if the shell was compiled with MULTIBYTE_SUPPORT;
              otherwise it is off by default and has no effect if turned on.

              If the option is off a single byte is always treated as a single  character.   This
              setting  is  designed  purely  for  examining strings known to contain raw bytes or
              other values that may not be characters in the current locale.  It is not necessary
              to  unset  the  option merely because the character set for the current locale does
              not contain multibyte characters.

              The option does not affect the shell's editor,  which always  uses  the  locale  to
              determine multibyte characters.  This is because the character set displayed by the
              terminal emulator is independent of shell settings.

       NOMATCH (+3) <C> <Z>
              If a pattern for filename generation has no matches, print  an  error,  instead  of
              leaving  it unchanged in the argument list.  This also applies to file expansion of
              an initial `~' or `='.

       NULL_GLOB (-G)
              If a pattern for filename generation has no matches, delete the  pattern  from  the
              argument list instead of reporting an error.  Overrides NOMATCH.

       NUMERIC_GLOB_SORT
              If  numeric  filenames  are  matched  by  a  filename  generation pattern, sort the
              filenames numerically rather than lexicographically.

       RC_EXPAND_PARAM (-P)
              Array expansions of the form `foo${xx}bar', where the parameter xx is set to  (a  b
              c),  are  substituted with `fooabar foobbar foocbar' instead of the default `fooa b
              cbar'.  Note that an empty array will therefore cause all arguments to be removed.

       REMATCH_PCRE
              If set, regular expression matching with the =~ operator will  use  Perl-Compatible
              Regular   Expressions  from  the  PCRE  library.   (The  zsh/pcre  module  must  be
              available.)  If not set, regular expressions will use the  extended  regexp  syntax
              provided by the system libraries.

       SH_GLOB <K> <S>
              Disables  the  special  meaning of `(', `|', `)' and '<' for globbing the result of
              parameter and command substitutions, and in  some  other  places  where  the  shell
              accepts  patterns.   If  SH_GLOB  is  set but KSH_GLOB is not, the shell allows the
              interpretation of subshell expressions enclosed in parentheses in some cases  where
              there is no space before the opening parenthesis, e.g. !(true) is interpreted as if
              there were a space after the !.  This option is set by default if zsh is invoked as
              sh or ksh.

       UNSET (+u, ksh: +u) <K> <S> <Z>
              Treat unset parameters as if they were empty when substituting, and as if they were
              zero when reading their values in arithmetic  expansion  and  arithmetic  commands.
              Otherwise they are treated as an error.

       WARN_CREATE_GLOBAL
              Print  a  warning  message  when  a global parameter is created in a function by an
              assignment or in math context.  This often indicates that a parameter has not  been
              declared  local  when  it  should have been.  Parameters explicitly declared global
              from within a function using typeset -g do not cause a warning.  Note that there is
              no  warning  when  a local parameter is assigned to in a nested function, which may
              also indicate an error.

       WARN_NESTED_VAR
              Print a warning message when an  existing  parameter  from  an  enclosing  function
              scope,  or  global,  is  set  in  a  function  by an assignment or in math context.
              Assignment to shell special parameters does not  cause  a  warning.   This  is  the
              companion  to WARN_CREATE_GLOBAL as in this case the warning is only printed when a
              parameter is not created.  Where possible, use of typeset -g to set  the  parameter
              suppresses  the error, but note that this needs to be used every time the parameter
              is set.  To restrict the effect of this option to  a  single  function  scope,  use
              `functions -W'.

              For  example,  the  following code produces a warning for the assignment inside the
              function nested as that overrides the value within toplevel

                     toplevel() {
                       local foo="in fn"
                       nested
                     }
                     nested() {
                          foo="in nested"
                     }
                     setopt warn_nested_var
                     toplevel

   History
       APPEND_HISTORY <D>
              If this is set, zsh sessions will append their history list to  the  history  file,
              rather  than replace it. Thus, multiple parallel zsh sessions will all have the new
              entries from their history lists added to the history file, in the order that  they
              exit.  The file will still be periodically re-written to trim it when the number of
              lines  grows  20%  beyond  the  value  specified  by  $SAVEHIST   (see   also   the
              HIST_SAVE_BY_COPY option).

       BANG_HIST (+K) <C> <Z>
              Perform textual history expansion, csh-style, treating the character `!' specially.

       EXTENDED_HISTORY <C>
              Save  each  command's  beginning  timestamp  (in  seconds  since the epoch) and the
              duration (in seconds) to the history file.  The format of this prefixed data is:

              `: <beginning time>:<elapsed seconds>;<command>'.

       HIST_ALLOW_CLOBBER
              Add `|' to output redirections in the history.  This allows history  references  to
              clobber files even when CLOBBER is unset.

       HIST_BEEP <D>
              Beep in ZLE when a widget attempts to access a history entry which isn't there.

       HIST_EXPIRE_DUPS_FIRST
              If  the  internal  history  needs  to  be  trimmed to add the current command line,
              setting this option will cause the oldest history event that has a duplicate to  be
              lost  before  losing  a  unique event from the list.  You should be sure to set the
              value of HISTSIZE to a larger number than SAVEHIST in order to give you  some  room
              for   the   duplicated   events,  otherwise  this  option  will  behave  just  like
              HIST_IGNORE_ALL_DUPS once the history fills up with unique events.

       HIST_FCNTL_LOCK
              When writing out the history file, by default zsh uses ad-hoc file locking to avoid
              known problems with locking on some operating systems.  With this option locking is
              done by means of the system's fcntl call,  where  this  method  is  available.   On
              recent  operating  systems  this  may  provide  better  performance,  in particular
              avoiding history corruption when files are stored on NFS.

       HIST_FIND_NO_DUPS
              When searching for history entries in the line editor, do not display duplicates of
              a line previously found, even if the duplicates are not contiguous.

       HIST_IGNORE_ALL_DUPS
              If  a new command line being added to the history list duplicates an older one, the
              older command is removed from the list (even if it is not the previous event).

       HIST_IGNORE_DUPS (-h)
              Do not enter command lines into the history list if  they  are  duplicates  of  the
              previous event.

       HIST_IGNORE_SPACE (-g)
              Remove  command lines from the history list when the first character on the line is
              a space, or when one of the expanded aliases contains a leading space.  Only normal
              aliases  (not global or suffix aliases) have this behaviour.  Note that the command
              lingers in the internal history  until  the  next  command  is  entered  before  it
              vanishes,  allowing  you to briefly reuse or edit the line.  If you want to make it
              vanish right away without entering another command, type a space and press return.

       HIST_LEX_WORDS
              By default, shell history that is read in from files is split  into  words  on  all
              white  space.   This  means that arguments with quoted whitespace are not correctly
              handled, with the consequence that references to words in history lines  that  have
              been  read  from  a file may be inaccurate.  When this option is set, words read in
              from a history file are divided up in a similar fashion  to  normal  shell  command
              line handling.  Although this produces more accurately delimited words, if the size
              of the history file is large this can be slow.  Trial and  error  is  necessary  to
              decide.

       HIST_NO_FUNCTIONS
              Remove  function definitions from the history list.  Note that the function lingers
              in the internal history until the next  command  is  entered  before  it  vanishes,
              allowing you to briefly reuse or edit the definition.

       HIST_NO_STORE
              Remove  the  history (fc -l) command from the history list when invoked.  Note that
              the command lingers in the internal history  until  the  next  command  is  entered
              before it vanishes, allowing you to briefly reuse or edit the line.

       HIST_REDUCE_BLANKS
              Remove superfluous blanks from each command line being added to the history list.

       HIST_SAVE_BY_COPY <D>
              When the history file is re-written, we normally write out a copy of the file named
              $HISTFILE.new and then rename it over the old one.   However,  if  this  option  is
              unset,  we  instead  truncate  the  old  history file and write out the new version
              in-place.  If one of the history-appending options is enabled, this option only has
              an  effect when the enlarged history file needs to be re-written to trim it down to
              size.  Disable this only if you have special needs, as doing so makes  it  possible
              to lose history entries if zsh gets interrupted during the save.

              When  writing  out  a  copy  of  the  history  file,  zsh  preserves the old file's
              permissions and group information, but will refuse to write out a new  file  if  it
              would change the history file's owner.

       HIST_SAVE_NO_DUPS
              When  writing  out  the  history file, older commands that duplicate newer ones are
              omitted.

       HIST_VERIFY
              Whenever the user enters a line with history  expansion,  don't  execute  the  line
              directly;  instead,  perform history expansion and reload the line into the editing
              buffer.

       INC_APPEND_HISTORY
              This option works like APPEND_HISTORY except that new history lines  are  added  to
              the  $HISTFILE  incrementally  (as  soon  as they are entered), rather than waiting
              until the shell exits.  The file will still be periodically re-written to  trim  it
              when  the  number  of  lines grows 20% beyond the value specified by $SAVEHIST (see
              also the HIST_SAVE_BY_COPY option).

       INC_APPEND_HISTORY_TIME
              This option is a variant  of  INC_APPEND_HISTORY  in  which,  where  possible,  the
              history entry is written out to the file after the command is finished, so that the
              time  taken  by  the  command  is  recorded  correctly  in  the  history  file   in
              EXTENDED_HISTORY  format.   This means that the history entry will not be available
              immediately from other instances of the shell that are using the same history file.

              This option is only useful if INC_APPEND_HISTORY and SHARE_HISTORY are turned  off.
              The three options should be considered mutually exclusive.

       SHARE_HISTORY <K>

              This  option  both imports new commands from the history file, and also causes your
              typed commands to be appended to the history file (the latter  is  like  specifying
              INC_APPEND_HISTORY,  which  should be turned off if this option is in effect).  The
              history lines are also output with timestamps ala EXTENDED_HISTORY (which makes  it
              easier  to  find  the  spot  where  we  left  off  reading  the  file after it gets
              re-written).

              By default, history movement commands visit the imported lines as well as the local
              lines,  but  you can toggle this on and off with the set-local-history zle binding.
              It is also possible to create a zle widget that  will  make  some  commands  ignore
              imported commands, and some include them.

              If  you  find  that  you want more control over when commands get imported, you may
              wish to turn SHARE_HISTORY off, INC_APPEND_HISTORY or INC_APPEND_HISTORY_TIME  (see
              above) on, and then manually import commands whenever you need them using `fc -RI'.

   Initialisation
       ALL_EXPORT (-a, ksh: -a)
              All parameters subsequently defined are automatically exported.

       GLOBAL_EXPORT <Z>
              If this option is set, passing the -x flag to the builtins declare, float, integer,
              readonly and typeset (but not local) will also set the -g flag;   hence  parameters
              exported  to  the  environment  will  not  be made local to the enclosing function,
              unless they were already or the flag +g is given  explicitly.   If  the  option  is
              unset,  exported  parameters  will  be made local in just the same way as any other
              parameter.

              This option is set by default for backward compatibility;  it  is  not  recommended
              that  its  behaviour be relied upon.  Note that the builtin export always sets both
              the -x and -g flags, and hence its effect extends beyond the scope of the enclosing
              function; this is the most portable way to achieve this behaviour.

       GLOBAL_RCS (+d) <D>
              If  this  option  is  unset,  the  startup files /etc/zsh/zprofile, /etc/zsh/zshrc,
              /etc/zsh/zlogin and /etc/zsh/zlogout will not be  run.   It  can  be  disabled  and
              re-enabled at any time, including inside local startup files (.zshrc, etc.).

       RCS (+f) <D>
              After /etc/zsh/zshenv is sourced on startup, source the .zshenv, /etc/zsh/zprofile,
              .zprofile, /etc/zsh/zshrc, .zshrc, /etc/zsh/zlogin, .zlogin, and .zlogout files, as
              described  in  the  section  `Files'.  If this option is unset, the /etc/zsh/zshenv
              file is still sourced, but any of the others will not be; it can be set at any time
              to prevent the remaining startup files after the currently executing one from being
              sourced.

   Input/Output
       ALIASES <D>
              Expand aliases.

       CLOBBER (+C, ksh: +C) <D>
              Allows `>' redirection to truncate existing files.  Otherwise `>!' or `>|' must  be
              used to truncate a file.

              If  the  option  is not set, and the option APPEND_CREATE is also not set, `>>!' or
              `>>|' must be used to create a file.  If either option is set, `>>' may be used.

       CLOBBER_EMPTY
              This option is only used if the option CLOBBER is not set: note that it is  set  by
              default.

              If  this  option  is  set,  then  regular  files  of  zero length may be ovewritten
              (`clobbered').  Note that it is possible another process has written  to  the  file
              between  this  test and use of the file by the current process.  This option should
              therefore not be used in cases where files  to  be  clobbered  may  be  written  to
              asynchronously.

       CORRECT (-0)
              Try  to correct the spelling of commands.  Note that, when the HASH_LIST_ALL option
              is not set or when some directories in the path are not readable, this may  falsely
              report spelling errors the first time some commands are used.

              The  shell variable CORRECT_IGNORE may be set to a pattern to match words that will
              never be offered as corrections.

       CORRECT_ALL (-O)
              Try to correct the spelling of all arguments in a line.

              The shell variable CORRECT_IGNORE_FILE may be set to a pattern to match file  names
              that will never be offered as corrections.

       DVORAK Use  the  Dvorak  keyboard  instead  of the standard qwerty keyboard as a basis for
              examining spelling mistakes  for  the  CORRECT  and  CORRECT_ALL  options  and  the
              spell-word editor command.

       FLOW_CONTROL <D>
              If  this  option  is  unset, output flow control via start/stop characters (usually
              assigned to ^S/^Q) is disabled in the shell's editor.

       IGNORE_EOF (-7)
              Do not exit on end-of-file.  Require the use of exit or logout  instead.   However,
              ten  consecutive  EOFs  will  cause  the  shell  to exit anyway, to avoid the shell
              hanging if its tty goes away.

              Also, if this option is set and the Zsh Line Editor is used, widgets implemented by
              shell  functions  can  be  bound  to  EOF (normally Control-D) without printing the
              normal warning message.  This works only for normal  widgets,  not  for  completion
              widgets.

       INTERACTIVE_COMMENTS (-k) <K> <S>
              Allow comments even in interactive shells.

       HASH_CMDS <D>
              Note  the  location  of  each  command  the  first time it is executed.  Subsequent
              invocations of the same command will  use  the  saved  location,  avoiding  a  path
              search.   If  this  option is unset, no path hashing is done at all.  However, when
              CORRECT is set, commands whose names do not appear in the functions or aliases hash
              tables are hashed in order to avoid reporting them as spelling errors.

       HASH_DIRS <D>
              Whenever a command name is hashed, hash the directory containing it, as well as all
              directories that occur earlier in the path.  Has no effect if neither HASH_CMDS nor
              CORRECT is set.

       HASH_EXECUTABLES_ONLY
              When  hashing  commands  because  of HASH_CMDS, check that the file to be hashed is
              actually an executable.  This option is unset by default as if the path contains  a
              large  number  of  commands, or consists of many remote files, the additional tests
              can take a long time.  Trial and  error  is  needed  to  show  if  this  option  is
              beneficial.

       MAIL_WARNING (-U)
              Print  a  warning  message  if  a  mail file has been accessed since the shell last
              checked.

       PATH_DIRS (-Q)
              Perform a path search even  on  command  names  with  slashes  in  them.   Thus  if
              `/usr/local/bin'  is  in  the  user's  path,  and  he or she types `X11/xinit', the
              command `/usr/local/bin/X11/xinit' will be executed (assuming it exists).  Commands
              explicitly  beginning  with  `/', `./' or `../' are not subject to the path search.
              This also applies to the `.' and source builtins.

              Note  that  subdirectories  of  the  current  directory  are  always  searched  for
              executables  specified  in this form.  This takes place before any search indicated
              by this option, and regardless of whether `.' or the current  directory  appear  in
              the command search path.

       PATH_SCRIPT <K> <S>
              If  this option is not set, a script passed as the first non-option argument to the
              shell must contain the name of the file to open.  If this option is  set,  and  the
              script  does  not  specify  a directory path, the script is looked for first in the
              current directory, then in the command path.  See the section INVOCATION in zsh(1).

       PRINT_EIGHT_BIT
              Print eight bit characters literally in completion lists, etc.  This option is  not
              necessary if your system correctly returns the printability of eight bit characters
              (see ctype(3)).

       PRINT_EXIT_VALUE (-1)
              Print the exit value of programs with non-zero exit status.  This is only available
              at the command line in interactive shells.

       RC_QUOTES
              Allow  the  character  sequence `''' to signify a single quote within singly quoted
              strings.  Note this does not apply in quoted strings using the format $'...', where
              a backslashed single quote can be used.

       RM_STAR_SILENT (-H) <K> <S>
              Do not query the user before executing `rm *' or `rm path/*'.

       RM_STAR_WAIT
              If querying the user before executing `rm *' or `rm path/*', first wait ten seconds
              and ignore anything typed in that time.  This avoids  the  problem  of  reflexively
              answering  `yes'  to  the query when one didn't really mean it.  The wait and query
              can always be avoided by expanding the `*' in ZLE (with tab).

       SHORT_LOOPS <C> <Z>
              Allow the short forms of for, repeat, select, if, and function constructs.

       SHORT_REPEAT
              Allow the short form repeat as SHORT_LOOPS but without enabling it  for  the  other
              constructs.

       SUN_KEYBOARD_HACK (-L)
              If  a  line ends with a backquote, and there are an odd number of backquotes on the
              line, ignore the trailing backquote.  This is useful on some  keyboards  where  the
              return  key is too small, and the backquote key lies annoyingly close to it.  As an
              alternative the variable KEYBOARD_HACK lets you choose the character to be removed.

   Job Control
       AUTO_CONTINUE
              With this option set, stopped jobs that are removed from the  job  table  with  the
              disown builtin command are automatically sent a CONT signal to make them running.

       AUTO_RESUME (-W)
              Treat  single word simple commands without redirection as candidates for resumption
              of an existing job.

       BG_NICE (-6) <C> <Z>
              Run all background jobs at a lower priority.  This option is set by default.

       CHECK_JOBS <Z>
              Report the status of background and suspended jobs before exiting a shell with  job
              control;  a  second  attempt to exit the shell will succeed.  NO_CHECK_JOBS is best
              used only in combination with NO_HUP, else such jobs will be killed automatically.

              The check is omitted if the commands run from the previous command line included  a
              `jobs'  command, since it is assumed the user is aware that there are background or
              suspended jobs.  A `jobs' command run from one of the hook functions defined in the
              section SPECIAL FUNCTIONS in zshmisc(1) is not counted for this purpose.

       CHECK_RUNNING_JOBS <Z>
              Check  for  both  running and suspended jobs when CHECK_JOBS is enabled.  When this
              option is disabled, zsh checks only for suspended jobs, which matches  the  default
              behavior of bash.

              This option has no effect unless CHECK_JOBS is set.

       HUP <Z>
              Send the HUP signal to running jobs when the shell exits.

       LONG_LIST_JOBS (-R)
              Print job notifications in the long format by default.

       MONITOR (-m, ksh: -m)
              Allow job control.  Set by default in interactive shells.

       NOTIFY (-5, ksh: -b) <Z>
              Report  the  status  of background jobs immediately, rather than waiting until just
              before printing a prompt.

       POSIX_JOBS <K> <S>
              This option makes job control more compliant with the POSIX standard.

              When the option is not set, the MONITOR option is unset on entry to  subshells,  so
              that  job  control is no longer active.  When the option is set, the MONITOR option
              and job control remain active in the subshell, but note that the  subshell  has  no
              access to jobs in the parent shell.

              When  the option is not set, jobs put in the background or foreground with bg or fg
              are displayed with the same information that would be reported by jobs.   When  the
              option  is  set,  only  the  text  is  printed.  The output from jobs itself is not
              affected by the option.

              When the option is not set, job information from the  parent  shell  is  saved  for
              output within a subshell (for example, within a pipeline).  When the option is set,
              the output of jobs is empty until a job is started within the subshell.

              In previous versions of the shell, it was necessary to enable POSIX_JOBS  in  order
              for  the  builtin  command  wait  to  return the status of background jobs that had
              already exited.  This is no longer the case.

   Prompting
       PROMPT_BANG <K>
              If set, `!' is treated specially in prompt  expansion.   See  EXPANSION  OF  PROMPT
              SEQUENCES in zshmisc(1).

       PROMPT_CR (+V) <D>
              Print  a carriage return just before printing a prompt in the line editor.  This is
              on by default as multi-line editing is only possible if the editor knows where  the
              start of the line appears.

       PROMPT_SP <D>
              Attempt  to  preserve  a partial line (i.e. a line that did not end with a newline)
              that would otherwise be covered up by the  command  prompt  due  to  the  PROMPT_CR
              option.   This  works  by  outputting  some  cursor-control characters, including a
              series of spaces, that should make the terminal  wrap  to  the  next  line  when  a
              partial  line  is  present  (note that this is only successful if your terminal has
              automatic margins, which is typical).

              When a partial line is preserved, by default you will see an inverse+bold character
              at  the  end  of  the partial line:  a `%' for a normal user or a `#' for root.  If
              set, the shell parameter PROMPT_EOL_MARK can be used to customize how  the  end  of
              partial lines are shown.

              NOTE: if the PROMPT_CR option is not set, enabling this option will have no effect.
              This option is on by default.

       PROMPT_PERCENT <C> <Z>
              If set, `%' is treated specially in prompt  expansion.   See  EXPANSION  OF  PROMPT
              SEQUENCES in zshmisc(1).

       PROMPT_SUBST <K> <S>
              If  set,  parameter  expansion,  command  substitution and arithmetic expansion are
              performed in prompts.  Substitutions within  prompts  do  not  affect  the  command
              status.

       TRANSIENT_RPROMPT
              Remove  any  right  prompt from display when accepting a command line.  This may be
              useful with terminals with other cut/paste methods.

   Scripts and Functions
       ALIAS_FUNC_DEF <S>
              By default, zsh does not allow the definition of  functions  using  the  `name  ()'
              syntax if name was expanded as an alias: this causes an error.  This is usually the
              desired behaviour, as otherwise the combination of an alias and a function based on
              the same definition can easily cause problems.

              When this option is set, aliases can be used for defining functions.

              For  example,  consider  the following definitions as they might occur in a startup
              file.

                     alias foo=bar
                     foo() {
                       print This probably does not do what you expect.
                     }

              Here, foo is expanded as an alias to bar before  the  ()  is  encountered,  so  the
              function defined would be named bar.  By default this is instead an error in native
              mode.  Note that quoting any part of  the  function  name,  or  using  the  keyword
              function,  avoids the problem, so is recommended when the function name can also be
              an alias.

       C_BASES
              Output hexadecimal numbers in the standard C format, for example `0xFF' instead  of
              the  usual `16#FF'.  If the option OCTAL_ZEROES is also set (it is not by default),
              octal numbers will be treated similarly  and  hence  appear  as  `077'  instead  of
              `8#77'.   This  option  has  no effect on the choice of the output base, nor on the
              output of bases other than hexadecimal and octal.  Note that these formats will  be
              understood on input irrespective of the setting of C_BASES.

       C_PRECEDENCES
              This  alters  the  precedence  of  arithmetic operators to be more like C and other
              programming languages; the section  ARITHMETIC  EVALUATION  in  zshmisc(1)  has  an
              explicit list.

       DEBUG_BEFORE_CMD <D>
              Run  the  DEBUG  trap  before each command; otherwise it is run after each command.
              Setting this option mimics the behaviour of ksh  93;  with  the  option  unset  the
              behaviour is that of ksh 88.

       ERR_EXIT (-e, ksh: -e)
              If  a  command has a non-zero exit status, execute the ZERR trap, if set, and exit.
              This is disabled while running initialization scripts.

              The behaviour is also disabled inside DEBUG traps.  In  this  case  the  option  is
              handled   specially:   it   is   unset  on  entry  to  the  trap.   If  the  option
              DEBUG_BEFORE_CMD is set, as it is by default, and the option ERR_EXIT is  found  to
              have  been set on exit, then the command for which the DEBUG trap is being executed
              is skipped.  The option is restored after the trap exits.

              Non-zero status in a command list containing && or || is ignored for  commands  not
              at the end of the list.  Hence

                     false && true

              does not trigger exit.

              Exiting  due  to  ERR_EXIT has certain interactions with asynchronous jobs noted in
              the section JOBS in zshmisc(1).

       ERR_RETURN
              If a command has a non-zero exit status,  return  immediately  from  the  enclosing
              function.   The  logic  is  similar  to  that for ERR_EXIT, except that an implicit
              return statement is executed instead of an exit.  This will trigger an exit at  the
              outermost level of a non-interactive script.

              Normally  this option inherits the behaviour of ERR_EXIT that code followed by `&&'
              `||' does not trigger a return.  Hence in the following:

                     summit || true

              no return is forced as the combined effect always has a zero return status.

              Note. however, that if summit in the above  example  is  itself  a  function,  code
              inside it is considered separately: it may force a return from summit (assuming the
              option remains set within summit),  but  not  from  the  enclosing  context.   This
              behaviour is different from ERR_EXIT which is unaffected by function scope.

       EVAL_LINENO <Z>
              If  set,  line  numbers of expressions evaluated using the builtin eval are tracked
              separately of the enclosing environment.  This applies both to the parameter LINENO
              and  the  line  number  output  by the prompt escape %i.  If the option is set, the
              prompt escape %N will output the string `(eval)' instead of the script or  function
              name  as  an  indication.    (The  two  prompt  escapes  are  typically used in the
              parameter PS4 to be output when the option  XTRACE  is  set.)   If  EVAL_LINENO  is
              unset, the line number of the surrounding script or function is retained during the
              evaluation.

       EXEC (+n, ksh: +n) <D>
              Do execute commands.  Without this option, commands are read and checked for syntax
              errors,  but  not  executed.   This  option  cannot be turned off in an interactive
              shell, except when `-n' is supplied to the shell at startup.

       FUNCTION_ARGZERO <C> <Z>
              When executing a shell function or sourcing a script, set  $0  temporarily  to  the
              name  of  the  function/script.  Note that toggling FUNCTION_ARGZERO from on to off
              (or off to on) does not change the current value of $0.  Only the state upon  entry
              to the function or script has an effect.  Compare POSIX_ARGZERO.

       LOCAL_LOOPS
              When  this  option  is  not  set,  the  effect  of  break and continue commands may
              propagate outside function scope, affecting loops in calling functions.   When  the
              option  is  set  in  a  calling  function, a break or a continue that is not caught
              within a called function (regardless of the  setting  of  the  option  within  that
              function) produces a warning and the effect is cancelled.

       LOCAL_OPTIONS <K>
              If  this  option  is set at the point of return from a shell function, most options
              (including this one) which were in force upon entry to the function  are  restored;
              options  that are not restored are PRIVILEGED and RESTRICTED.  Otherwise, only this
              option, and the LOCAL_LOOPS, XTRACE  and  PRINT_EXIT_VALUE  options  are  restored.
              Hence if this is explicitly unset by a shell function the other options in force at
              the point of return will remain so.  A shell function can also guarantee  itself  a
              known  shell  configuration  with  a  formulation  like  `emulate  -L  zsh'; the -L
              activates LOCAL_OPTIONS.

       LOCAL_PATTERNS
              If this option is set at the point of return from a shell function,  the  state  of
              pattern disables, as set with the builtin command `disable -p', is restored to what
              it was when the function was entered.  The behaviour of this option is  similar  to
              the  effect of LOCAL_OPTIONS on options; hence `emulate -L sh' (or indeed any other
              emulation with the -L option) activates LOCAL_PATTERNS.

       LOCAL_TRAPS <K>
              If this option is set when a signal  trap  is  set  inside  a  function,  then  the
              previous  status  of  the  trap  for that signal will be restored when the function
              exits.  Note that this option must be set prior to altering the trap behaviour in a
              function;  unlike LOCAL_OPTIONS, the value on exit from the function is irrelevant.
              However, it does not need to be set before any global trap for that to be correctly
              restored by a function.  For example,

                     unsetopt localtraps
                     trap - INT
                     fn() { setopt localtraps; trap '' INT; sleep 3; }

              will restore normal handling of SIGINT after the function exits.

       MULTI_FUNC_DEF <Z>
              Allow  definitions of multiple functions at once in the form `fn1 fn2...()'; if the
              option is not set, this causes a parse error.   Definition  of  multiple  functions
              with the function keyword is always allowed.  Multiple function definitions are not
              often used and can cause obscure errors.

       MULTIOS <Z>
              Perform implicit tees or cats when multiple redirections  are  attempted  (see  the
              section `Redirection').

       OCTAL_ZEROES <S>
              Interpret  any  integer  constant  beginning  with  a  0  as  octal,  per  IEEE Std
              1003.2-1992 (ISO 9945-2:1993).  This  is  not  enabled  by  default  as  it  causes
              problems with parsing of, for example, date and time strings with leading zeroes.

              Sequences of digits indicating a numeric base such as the `08' component in `08#77'
              are always interpreted as decimal, regardless of leading zeroes.

       PIPE_FAIL
              By default, when a pipeline exits  the  exit  status  recorded  by  the  shell  and
              returned  by  the  shell  variable  $?  reflects that of the rightmost element of a
              pipeline.  If this option is set, the exit status instead reflects  the  status  of
              the  rightmost  element  of the pipeline that was non-zero, or zero if all elements
              exited with zero status.

       SOURCE_TRACE
              If set, zsh will print an informational message announcing the name of each file it
              loads.  The format of the output is similar to that for the XTRACE option, with the
              message <sourcetrace>.  A file may be loaded by the shell itself when it starts  up
              and  shuts  down  (Startup/Shutdown  Files) or by the use of the `source' and `dot'
              builtin commands.

       TYPESET_SILENT
              If this is unset, executing any of the `typeset' family of commands with no options
              and  a list of parameters that have no values to be assigned but already exist will
              display the value of the parameter.  If the option is set, they will only be  shown
              when  parameters  are  selected with the `-m' option.  The option `-p' is available
              whether or not the option is set.

       TYPESET_TO_UNSET <K> <S>
              When declaring a new  parameter  with  any  of  the  `typeset'  family  of  related
              commands,  the  parameter  remains  unset  unless  and  until a value is explicitly
              assigned to it, either in the `typeset' command itself or  as  a  later  assignment
              statement.

       VERBOSE (-v, ksh: -v)
              Print shell input lines as they are read.

       XTRACE (-x, ksh: -x)
              Print commands and their arguments as they are executed.  The output is preceded by
              the value of $PS4, formatted as  described  in  the  section  EXPANSION  OF  PROMPT
              SEQUENCES in zshmisc(1).

   Shell Emulation
       APPEND_CREATE <K> <S>
              This option only applies when NO_CLOBBER (-C) is in effect.

              If this option is not set, the shell will report an error when a append redirection
              (>>) is used on a file that does not already exists (the traditional zsh  behaviour
              of NO_CLOBBER).  If the option is set, no error is reported (POSIX behaviour).

       BASH_REMATCH
              When  set,  matches  performed with the =~ operator will set the BASH_REMATCH array
              variable, instead of the default MATCH and match variables.  The first  element  of
              the BASH_REMATCH array will contain the entire matched text and subsequent elements
              will contain extracted substrings.  This option makes more sense when KSH_ARRAYS is
              also  set,  so  that  the entire matched portion is stored at index 0 and the first
              substring is at index 1.  Without this option,  the  MATCH  variable  contains  the
              entire matched text and the match array variable contains substrings.

       BSD_ECHO <S>
              Make  the  echo  builtin  compatible  with  the BSD echo(1) command.  This disables
              backslashed escape sequences in echo strings unless the -e option is specified.

       CONTINUE_ON_ERROR
              If a fatal error is encountered (see the section ERRORS  in  zshmisc(1)),  and  the
              code  is running in a script, the shell will resume execution at the next statement
              in the script at the top level, in other  words  outside  all  functions  or  shell
              constructs  such as loops and conditions.  This mimics the behaviour of interactive
              shells, where the shell returns to the line editor to read a new  command;  it  was
              the normal behaviour in versions of zsh before 5.0.1.

       CSH_JUNKIE_HISTORY <C>
              A  history  reference  without an event specifier will always refer to the previous
              command.  Without this option, such a history reference refers to the same event as
              the  previous  history  reference  on  the  current command line, defaulting to the
              previous command.

       CSH_JUNKIE_LOOPS <C>
              Allow loop bodies to take the form `list; end' instead of `do list; done'.

       CSH_JUNKIE_QUOTES <C>
              Changes the rules for single- and double-quoted text to match that of  csh.   These
              require  that embedded newlines be preceded by a backslash; unescaped newlines will
              cause an error message.  In double-quoted strings, it is made impossible to  escape
              `$',  ``'  or `"' (and `\' itself no longer needs escaping).  Command substitutions
              are only expanded once, and cannot be nested.

       CSH_NULLCMD <C>
              Do not use the values of NULLCMD and READNULLCMD when running redirections with  no
              command.  This make such redirections fail (see the section `Redirection').

       KSH_ARRAYS <K> <S>
              Emulate  ksh  array  handling as closely as possible.  If this option is set, array
              elements are numbered from zero, an array parameter without subscript refers to the
              first  element  instead  of  the  whole array, and braces are required to delimit a
              subscript (`${path[2]}' rather than just `$path[2]') or to apply modifiers  to  any
              parameter (`${PWD:h}' rather than `$PWD:h').

       KSH_AUTOLOAD <K> <S>
              Emulate  ksh  function autoloading.  This means that when a function is autoloaded,
              the corresponding file is merely executed, and must  define  the  function  itself.
              (By  default,  the  function  is defined to the contents of the file.  However, the
              most common ksh-style case - of the file containing only a simple definition of the
              function - is always handled in the ksh-compatible manner.)

       KSH_OPTION_PRINT <K>
              Alters  the  way options settings are printed: instead of separate lists of set and
              unset options, all options are shown, marked `on' if they are  in  the  non-default
              state, `off' otherwise.

       KSH_TYPESET
              This  option  is  now  obsolete:  a better appropximation to the behaviour of other
              shells is obtained with the reserved word  interface  to  declare,  export,  float,
              integer,  local,  readonly  and typeset.  Note that the option is only applied when
              the reserved word interface is not in use.

              Alters the way arguments to the typeset  family  of  commands,  including  declare,
              export,  float,  integer,  local and readonly, are processed.  Without this option,
              zsh will perform normal word splitting after command  and  parameter  expansion  in
              arguments  of  an  assignment; with it, word splitting does not take place in those
              cases.

       KSH_ZERO_SUBSCRIPT
              Treat use of a subscript of  value  zero  in  array  or  string  expressions  as  a
              reference  to the first element, i.e. the element that usually has the subscript 1.
              Ignored if KSH_ARRAYS is also set.

              If neither this option nor KSH_ARRAYS is set, accesses to an element of an array or
              string with subscript zero return an empty element or string, while attempts to set
              element zero of an array or string are treated as an error.  However,  attempts  to
              set  an  otherwise  valid  subscript  range  that  includes zero will succeed.  For
              example, if KSH_ZERO_SUBSCRIPT is not set,

                     array[0]=(element)

              is an error, while

                     array[0,1]=(element)

              is not and will replace the first element of the array.

              This option is for compatibility with older  versions  of  the  shell  and  is  not
              recommended in new code.

       POSIX_ALIASES <K> <S>
              When this option is set, reserved words are not candidates for alias expansion:  it
              is still possible to declare any of them as an alias, but the alias will  never  be
              expanded.    Reserved  words  are  described  in  the  section  RESERVED  WORDS  in
              zshmisc(1).

              Alias expansion takes place while text is being read; hence when this option is set
              it  does not take effect until the end of any function or other piece of shell code
              parsed as one unit.  Note this may cause differences from other  shells  even  when
              the  option  is  in  effect.  For example, when running a command with `zsh -c', or
              even `zsh -o posixaliases -c', the entire command argument is parsed as  one  unit,
              so  aliases  defined within the argument are not available even in later lines.  If
              in doubt, avoid use of aliases in non-interactive code.

       POSIX_ARGZERO
              This option may be used to temporarily disable FUNCTION_ARGZERO and thereby restore
              the  value  of $0 to the name used to invoke the shell (or as set by the -c command
              line option).  For compatibility with previous versions of  the  shell,  emulations
              use  NO_FUNCTION_ARGZERO  instead  of POSIX_ARGZERO, which may result in unexpected
              scoping of $0 if the emulation mode is changed inside a  function  or  script.   To
              avoid this, explicitly enable POSIX_ARGZERO in the emulate command:

                     emulate sh -o POSIX_ARGZERO

              Note  that  NO_POSIX_ARGZERO  has  no  effect  unless  FUNCTION_ARGZERO was already
              enabled upon entry to the function or script.

       POSIX_BUILTINS <K> <S>
              When this option is set the command builtin can be used to  execute  shell  builtin
              commands.   Parameter  assignments  specified  before  shell  functions and special
              builtins are kept after  the  command  completes  unless  the  special  builtin  is
              prefixed  with  the  command  builtin.  Special builtins are ., :, break, continue,
              declare, eval, exit, export, integer, local, readonly, return, set, shift,  source,
              times, trap and unset.

              In  addition,  various  error conditions associated with the above builtins or exec
              cause a non-interactive shell to exit and an interactive shell  to  return  to  its
              top-level processing.

              Furthermore,  functions  and  shell builtins are not executed after an exec prefix;
              the command to be executed must be an external command found in the path.

              Furthermore, the getopts builtin behaves in a POSIX-compatible fashion in that  the
              associated  variable  OPTIND  is  not  made  local  to  functions, and its value is
              calculated differently to match other shells.

              Moreover, the warning and special exit code from [[ -o non_existent_option  ]]  are
              suppressed.

       POSIX_IDENTIFIERS <K> <S>
              When this option is set, only the ASCII characters a to z, A to Z, 0 to 9 and _ may
              be used in identifiers (names of shell parameters and modules).

              In addition, setting this option limits the effect of parameter  substitution  with
              no  braces,  so  that  the  expression  $#  is  treated as the parameter $# even if
              followed by a valid parameter name.  When it is unset, zsh  allows  expressions  of
              the  form  $#name  to refer to the length of $name, even for special variables, for
              example in expressions such as $#- and $#*.

              Another difference is that with the option set assignment to an unset  variable  in
              arithmetic  context  causes  the  variable  to be created as a scalar rather than a
              numeric type.  So after `unset t; (( t = 3 ))'. without POSIX_IDENTIFIERS set t has
              integer type, while with it set it has scalar type.

              When  the  option  is  unset and multibyte character support is enabled (i.e. it is
              compiled in and the option MULTIBYTE is set), then  additionally  any  alphanumeric
              characters  in  the  local  character  set  may  be used in identifiers.  Note that
              scripts and functions written with this feature are not  portable,  and  also  that
              both  options  must  be  set  before the script or function is parsed; setting them
              during execution is not sufficient as the syntax variable=value  has  already  been
              parsed as a command rather than an assignment.

              If  multibyte  character  support  is  not  compiled  into the shell this option is
              ignored; all octets with the top bit set may  be  used  in  identifiers.   This  is
              non-standard but is the traditional zsh behaviour.

       POSIX_STRINGS <K> <S>
              This  option  affects  processing of quoted strings.  Currently it only affects the
              behaviour of null characters, i.e.  character  0  in  the  portable  character  set
              corresponding to US ASCII.

              When  this  option  is not set, null characters embedded within strings of the form
              $'...' are treated as ordinary characters. The entire string is  maintained  within
              the  shell  and  output to files where necessary, although owing to restrictions of
              the library interface the string is truncated at the null character in file  names,
              environment variables, or in arguments to external programs.

              When  this option is set, the $'...' expression is truncated at the null character.
              Note that remaining parts of the same string beyond the termination of  the  quotes
              are not truncated.

              For  example, the command line argument a$'b\0c'd is treated with the option off as
              the characters a, b, null, c, d, and with the option on as the characters a, b, d.

       POSIX_TRAPS <K> <S>
              When this option is set, the usual zsh behaviour of executing  traps  for  EXIT  on
              exit  from  shell  functions  is suppressed.  In that case, manipulating EXIT traps
              always alters the global trap for exiting the  shell;  the  LOCAL_TRAPS  option  is
              ignored for the EXIT trap.

              Also,  a  return statement executed in a trap with no argument passes back from the
              function the value from the surrounding context, not from code executed within  the
              trap.

              Furthermore, if a trap is set to be ignored, this state persists when a subshell is
              entered.  Without the option, the trap would be reset to its default state at  this
              point.

       SH_FILE_EXPANSION <K> <S>
              Perform  filename expansion (e.g., ~ expansion) before parameter expansion, command
              substitution, arithmetic expansion and brace expansion.  If this option  is  unset,
              it   is   performed   after  brace  expansion,  so  things  like  `~$USERNAME'  and
              `~{pfalstad,rc}' will work.

       SH_NULLCMD <K> <S>
              Do not use the values of NULLCMD and READNULLCMD when doing redirections,  use  `:'
              instead (see the section `Redirection').

       SH_OPTION_LETTERS <K> <S>
              If this option is set the shell tries to interpret single letter options (which are
              used with set and setopt) like ksh does.  This also affects  the  value  of  the  -
              special parameter.

       SH_WORD_SPLIT (-y) <K> <S>
              Causes field splitting to be performed on unquoted parameter expansions.  Note that
              this option has nothing to do with word splitting.  (See zshexpn(1).)

       TRAPS_ASYNC
              While waiting for a program to exit, handle  signals  and  run  traps  immediately.
              Otherwise  the  trap  is  run after a child process has exited.  Note this does not
              affect the point at which traps are run for any case other than when the  shell  is
              waiting for a child process.

   Shell State
       INTERACTIVE (-i, ksh: -i)
              This  is  an  interactive  shell.   This  option  is set upon initialisation if the
              standard input is a tty and commands are being read from standard input.  (See  the
              discussion  of SHIN_STDIN.)  This heuristic may be overridden by specifying a state
              for this option on the command line.  The value of this option can only be  changed
              via  flags  supplied  at invocation of the shell.  It cannot be changed once zsh is
              running.

       LOGIN (-l, ksh: -l)
              This is a login shell.  If this option is not explicitly set, the shell  becomes  a
              login shell if the first character of the argv[0] passed to the shell is a `-'.

       PRIVILEGED (-p, ksh: -p)
              Turn  on  privileged  mode.  Typically  this  is used when script is to be run with
              elevated privileges. This should be done as follows directly with the -p option  to
              zsh so that it takes effect during startup.

                     #!/bin/zsh -p

              The  option is enabled automatically on startup if the effective user (group) ID is
              not equal to the real user (group) ID. In this case, turning the option off  causes
              the effective user and group IDs to be set to the real user and group IDs. Be aware
              that if that fails the shell may be running with different IDs than was intended so
              a script should check for failure and act accordingly, for example:

                     unsetopt privileged || exit

              The  PRIVILEGED  option disables sourcing user startup files.  If zsh is invoked as
              `sh'  or  `ksh'  with  this  option  set,  /etc/suid_profile  is   sourced   (after
              /etc/profile  on  interactive  shells).  Sourcing  ~/.profile  is  disabled and the
              contents of the ENV variable is ignored. This option cannot be changed using the -m
              option  of setopt and unsetopt, and changing it inside a function always changes it
              globally regardless of the LOCAL_OPTIONS option.

       RESTRICTED (-r)
              Enables restricted mode.  This option cannot be changed using unsetopt, and setting
              it  inside  a  function  always changes it globally regardless of the LOCAL_OPTIONS
              option.  See the section `Restricted Shell'.

       SHIN_STDIN (-s, ksh: -s)
              Commands are being read from the standard input.  Commands are read  from  standard
              input  if no command is specified with -c and no file of commands is specified.  If
              SHIN_STDIN is set explicitly on the command line, any argument that would otherwise
              have  been  taken  as  a file to run will instead be treated as a normal positional
              parameter.  Note that setting or unsetting this option on the command line does not
              necessarily affect the state the option will have while the shell is running - that
              is purely an indicator of whether or not commands  are  actually  being  read  from
              standard input.  The value of this option can only be changed via flags supplied at
              invocation of the shell.  It cannot be changed once zsh is running.

       SINGLE_COMMAND (-t, ksh: -t)
              If the shell is reading from standard input, it exits after a  single  command  has
              been  executed.   This also makes the shell non-interactive, unless the INTERACTIVE
              option is explicitly set on the command line.  The value of this option can only be
              changed  via  flags supplied at invocation of the shell.  It cannot be changed once
              zsh is running.

   Zle
       BEEP (+B) <D>
              Beep on error in ZLE.

       COMBINING_CHARS
              Assume that the terminal displays combining characters correctly.  Specifically, if
              a  base  alphanumeric  character  is followed by one or more zero-width punctuation
              characters,  assume  that  the  zero-width  characters   will   be   displayed   as
              modifications  to  the  base  character  within  the same width.  Not all terminals
              handle this.  If this option  is  not  set,  zero-width  characters  are  displayed
              separately with special mark-up.

              If this option is set, the pattern test [[:WORD:]] matches a zero-width punctuation
              character on the assumption that it will be used as part of a word  in  combination
              with  a  word  character.   Otherwise  the  base  shell  does  not handle combining
              characters specially.

       EMACS  If ZLE is loaded, turning on this option has the equivalent effect of `bindkey -e'.
              In  addition,  the  VI  option is unset.  Turning it off has no effect.  The option
              setting is not guaranteed to reflect the current keymap.  This option  is  provided
              for compatibility; bindkey is the recommended interface.

       OVERSTRIKE
              Start up the line editor in overstrike mode.

       SINGLE_LINE_ZLE (-M) <K>
              Use single-line command line editing instead of multi-line.

              Note  that  although  this  is  on  by  default  in  ksh emulation it only provides
              superficial compatibility with the ksh line editor and reduces the effectiveness of
              the  zsh  line editor.  As it has no effect on shell syntax, many users may wish to
              disable this option when using ksh emulation interactively.

       VI     If ZLE is loaded, turning on this option has the equivalent effect of `bindkey -v'.
              In  addition, the EMACS option is unset.  Turning it off has no effect.  The option
              setting is not guaranteed to reflect the current keymap.  This option  is  provided
              for compatibility; bindkey is the recommended interface.

       ZLE (-Z)
              Use  the  zsh  line  editor.   Set  by default in interactive shells connected to a
              terminal.

OPTION ALIASES

       Some options have alternative names.  These aliases are never used for output, but can  be
       used just like normal option names when specifying options to the shell.

       BRACE_EXPAND
              NO_IGNORE_BRACES (ksh and bash compatibility)

       DOT_GLOB
              GLOB_DOTS (bash compatibility)

       HASH_ALL
              HASH_CMDS (bash compatibility)

       HIST_APPEND
              APPEND_HISTORY (bash compatibility)

       HIST_EXPAND
              BANG_HIST (bash compatibility)

       LOG    NO_HIST_NO_FUNCTIONS (ksh compatibility)

       MAIL_WARN
              MAIL_WARNING (bash compatibility)

       ONE_CMD
              SINGLE_COMMAND (bash compatibility)

       PHYSICAL
              CHASE_LINKS (ksh and bash compatibility)

       PROMPT_VARS
              PROMPT_SUBST (bash compatibility)

       STDIN  SHIN_STDIN (ksh compatibility)

       TRACK_ALL
              HASH_CMDS (ksh compatibility)

SINGLE LETTER OPTIONS

   Default set
       -0     CORRECT
       -1     PRINT_EXIT_VALUE
       -2     NO_BAD_PATTERN
       -3     NO_NOMATCH
       -4     GLOB_DOTS
       -5     NOTIFY
       -6     BG_NICE
       -7     IGNORE_EOF
       -8     MARK_DIRS
       -9     AUTO_LIST
       -B     NO_BEEP
       -C     NO_CLOBBER
       -D     PUSHD_TO_HOME
       -E     PUSHD_SILENT
       -F     NO_GLOB
       -G     NULL_GLOB
       -H     RM_STAR_SILENT
       -I     IGNORE_BRACES
       -J     AUTO_CD
       -K     NO_BANG_HIST
       -L     SUN_KEYBOARD_HACK
       -M     SINGLE_LINE_ZLE
       -N     AUTO_PUSHD
       -O     CORRECT_ALL
       -P     RC_EXPAND_PARAM
       -Q     PATH_DIRS
       -R     LONG_LIST_JOBS
       -S     REC_EXACT
       -T     CDABLE_VARS
       -U     MAIL_WARNING
       -V     NO_PROMPT_CR
       -W     AUTO_RESUME
       -X     LIST_TYPES
       -Y     MENU_COMPLETE
       -Z     ZLE
       -a     ALL_EXPORT
       -e     ERR_EXIT
       -f     NO_RCS
       -g     HIST_IGNORE_SPACE
       -h     HIST_IGNORE_DUPS
       -i     INTERACTIVE
       -k     INTERACTIVE_COMMENTS
       -l     LOGIN
       -m     MONITOR
       -n     NO_EXEC
       -p     PRIVILEGED
       -r     RESTRICTED
       -s     SHIN_STDIN
       -t     SINGLE_COMMAND
       -u     NO_UNSET
       -v     VERBOSE
       -w     CHASE_LINKS
       -x     XTRACE
       -y     SH_WORD_SPLIT

   sh/ksh emulation set
       -C     NO_CLOBBER
       -T     TRAPS_ASYNC
       -X     MARK_DIRS
       -a     ALL_EXPORT
       -b     NOTIFY
       -e     ERR_EXIT
       -f     NO_GLOB
       -i     INTERACTIVE
       -l     LOGIN
       -m     MONITOR
       -n     NO_EXEC
       -p     PRIVILEGED
       -r     RESTRICTED
       -s     SHIN_STDIN
       -t     SINGLE_COMMAND
       -u     NO_UNSET
       -v     VERBOSE
       -x     XTRACE

   Also note
       -A     Used by set for setting arrays
       -b     Used on the command line to specify end of option processing
       -c     Used on the command line to specify a single command
       -m     Used by setopt for pattern-matching option setting
       -o     Used in all places to allow use of long option names
       -s     Used by set to sort positional parameters