zsh-manual-mdbook/zsh_manual/src/Options.md

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**Table of Contents**  *generated with [DocToc](https://github.com/thlorenz/doctoc)*

- [16 Options](#16-options)
  - [16.1 Specifying Options](#161-specifying-options)
  - [16.2 Description of Options](#162-description-of-options)
    - [16.2.1 Changing Directories](#1621-changing-directories)
    - [16.2.2 Completion](#1622-completion)
    - [16.2.3 Expansion and Globbing](#1623-expansion-and-globbing)
    - [16.2.4 History](#1624-history)
    - [16.2.5 Initialisation](#1625-initialisation)
    - [16.2.6 Input/Output](#1626-inputoutput)
    - [16.2.7 Job Control](#1627-job-control)
    - [16.2.8 Prompting](#1628-prompting)
    - [16.2.9 Scripts and Functions](#1629-scripts-and-functions)
    - [16.2.10 Shell Emulation](#16210-shell-emulation)
    - [16.2.11 Shell State](#16211-shell-state)
    - [16.2.12 Zle](#16212-zle)
  - [16.3 Option Aliases](#163-option-aliases)
  - [16.4 Single Letter Options](#164-single-letter-options)
    - [16.4.1 Default set](#1641-default-set)
    - [16.4.2 sh/ksh emulation set](#1642-shksh-emulation-set)
    - [16.4.3 Also note](#1643-also-note)

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<span id="Options"></span> <span id="Options-3"></span>

# 16 Options

<span id="index-options"></span>

------------------------------------------------------------------------

<span id="Specifying-Options"></span> <span
id="Specifying-Options-1"></span>

## 16.1 Specifying Options

<span id="index-options_002c-specifying"></span>

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.

------------------------------------------------------------------------

<span id="Description-of-Options"></span> <span
id="Description-of-Options-1"></span>

## 16.2 Description of Options

<span id="index-options_002c-description"></span>

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.

------------------------------------------------------------------------

<span id="Changing-Directories"></span>

### 16.2.1 Changing Directories

<span id="index-AUTO_005fCD"></span> <span
id="index-NO_005fAUTO_005fCD"></span> <span id="index-AUTOCD"></span>
<span id="index-NOAUTOCD"></span> <span
id="index-cd_002c-automatic"></span>

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.

<span id="index-AUTO_005fPUSHD"></span> <span
id="index-NO_005fAUTO_005fPUSHD"></span> <span
id="index-AUTOPUSHD"></span> <span id="index-NOAUTOPUSHD"></span> <span
id="index-cd_002c-behaving-like-pushd"></span> <span
id="index-pushd_002c-making-cd-behave-like"></span>

AUTO_PUSHD (-N)

Make cd push the old directory onto the directory stack.

<span id="index-CDABLE_005fVARS"></span> <span
id="index-NO_005fCDABLE_005fVARS"></span> <span
id="index-CDABLEVARS"></span> <span id="index-NOCDABLEVARS"></span>
<span id="index-cd_002c-to-parameter"></span>

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 [Filename
Expansion](Expansion.html#Filename-Expansion)).

<span id="index-CD_005fSILENT"></span> <span
id="index-NO_005fCD_005fSILENT"></span> <span
id="index-CDSILENT"></span> <span id="index-NOCDSILENT"></span> <span
id="index-cd_002c-silencing"></span> <span
id="index-autocd_002c-silencing"></span>

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.

<span id="index-CHASE_005fDOTS"></span> <span
id="index-NO_005fCHASE_005fDOTS"></span> <span
id="index-CHASEDOTS"></span> <span id="index-NOCHASEDOTS"></span> <span
id="index-cd_002c-with-_002e_002e-in-argument"></span>

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.

<span id="index-CHASE_005fLINKS"></span> <span
id="index-NO_005fCHASE_005fLINKS"></span> <span
id="index-CHASELINKS"></span> <span id="index-NOCHASELINKS"></span>
<span id="index-links_002c-symbolic"></span> <span
id="index-symbolic-links"></span>

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.

<span id="index-POSIX_005fCD"></span> <span id="index-POSIXCD"></span>
<span id="index-NO_005fPOSIX_005fCD"></span> <span
id="index-NOPOSIXCD"></span> <span
id="index-CDPATH_002c-order-of-checking"></span>

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 [Shell Builtin
Commands](Shell-Builtin-Commands.html#Shell-Builtin-Commands). 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.

<span id="index-PUSHD_005fIGNORE_005fDUPS"></span> <span
id="index-NO_005fPUSHD_005fIGNORE_005fDUPS"></span> <span
id="index-PUSHDIGNOREDUPS"></span> <span
id="index-NOPUSHDIGNOREDUPS"></span> <span
id="index-directory-stack_002c-ignoring-duplicates"></span>

PUSHD_IGNORE_DUPS

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

<span id="index-PUSHD_005fMINUS"></span> <span
id="index-NO_005fPUSHD_005fMINUS"></span> <span
id="index-PUSHDMINUS"></span> <span id="index-NOPUSHDMINUS"></span>
<span id="index-directory-stack_002c-controlling-syntax"></span>

PUSHD_MINUS

Exchanges the meanings of ‘+’ and ‘-’ when used with a number to specify
a directory in the stack.

<span id="index-PUSHD_005fSILENT"></span> <span
id="index-NO_005fPUSHD_005fSILENT"></span> <span
id="index-PUSHDSILENT"></span> <span id="index-NOPUSHDSILENT"></span>
<span id="index-directory-stack_002c-silencing"></span>

PUSHD_SILENT (-E)

Do not print the directory stack after pushd or popd.

<span id="index-PUSHD_005fTO_005fHOME"></span> <span
id="index-NO_005fPUSHD_005fTO_005fHOME"></span> <span
id="index-PUSHDTOHOME"></span> <span id="index-NOPUSHDTOHOME"></span>
<span id="index-pushd_002c-to-home"></span>

PUSHD_TO_HOME (-D)

Have pushd with no arguments act like ‘pushd $HOME’.

------------------------------------------------------------------------

<span id="Completion-4"></span>

### 16.2.2 Completion

<span id="index-ALWAYS_005fLAST_005fPROMPT"></span> <span
id="index-NO_005fALWAYS_005fLAST_005fPROMPT"></span> <span
id="index-ALWAYSLASTPROMPT"></span> <span
id="index-NOALWAYSLASTPROMPT"></span>

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.

<span id="index-ALWAYS_005fTO_005fEND"></span> <span
id="index-NO_005fALWAYS_005fTO_005fEND"></span> <span
id="index-ALWAYSTOEND"></span> <span id="index-NOALWAYSTOEND"></span>

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.

<span id="index-AUTO_005fLIST"></span> <span
id="index-NO_005fAUTO_005fLIST"></span> <span
id="index-AUTOLIST"></span> <span id="index-NOAUTOLIST"></span> <span
id="index-completion_002c-listing-choices"></span>

AUTO_LIST (-9) \<D>

Automatically list choices on an ambiguous completion.

<span id="index-AUTO_005fMENU"></span> <span
id="index-NO_005fAUTO_005fMENU"></span> <span
id="index-AUTOMENU"></span> <span id="index-NOAUTOMENU"></span> <span
id="index-completion_002c-menu"></span>

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.

<span id="index-AUTO_005fNAME_005fDIRS"></span> <span
id="index-NO_005fAUTO_005fNAME_005fDIRS"></span> <span
id="index-AUTONAMEDIRS"></span> <span id="index-NOAUTONAMEDIRS"></span>
<span id="index-directories_002c-named"></span>

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.)

<span id="index-AUTO_005fPARAM_005fKEYS"></span> <span
id="index-NO_005fAUTO_005fPARAM_005fKEYS"></span> <span
id="index-AUTOPARAMKEYS"></span> <span
id="index-NOAUTOPARAMKEYS"></span>

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.

<span id="index-AUTO_005fPARAM_005fSLASH"></span> <span
id="index-NO_005fAUTO_005fPARAM_005fSLASH"></span> <span
id="index-AUTOPARAMSLASH"></span> <span
id="index-NOAUTOPARAMSLASH"></span>

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.

<span id="index-AUTO_005fREMOVE_005fSLASH"></span> <span
id="index-NO_005fAUTO_005fREMOVE_005fSLASH"></span> <span
id="index-AUTOREMOVESLASH"></span> <span
id="index-NOAUTOREMOVESLASH"></span> <span
id="index-slash_002c-removing-trailing"></span>

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.

<span id="index-BASH_005fAUTO_005fLIST"></span> <span
id="index-NO_005fBASH_005fAUTO_005fLIST"></span> <span
id="index-BASHAUTOLIST"></span> <span id="index-NOBASHAUTOLIST"></span>
<span id="index-completion_002c-listing-choices_002c-bash-style"></span>

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.

<span id="index-COMPLETE_005fALIASES"></span> <span
id="index-NO_005fCOMPLETE_005fALIASES"></span> <span
id="index-COMPLETEALIASES"></span> <span
id="index-NOCOMPLETEALIASES"></span> <span
id="index-aliases_002c-completion-of"></span>

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.

<span id="index-COMPLETE_005fIN_005fWORD"></span> <span
id="index-NO_005fCOMPLETE_005fIN_005fWORD"></span> <span
id="index-COMPLETEINWORD"></span> <span
id="index-NOCOMPLETEINWORD"></span>

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.

<span id="index-GLOB_005fCOMPLETE"></span> <span
id="index-NO_005fGLOB_005fCOMPLETE"></span> <span
id="index-GLOBCOMPLETE"></span> <span id="index-NOGLOBCOMPLETE"></span>

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.

<span id="index-HASH_005fLIST_005fALL"></span> <span
id="index-NO_005fHASH_005fLIST_005fALL"></span> <span
id="index-HASHLISTALL"></span> <span id="index-NOHASHLISTALL"></span>

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.

<span id="index-LIST_005fAMBIGUOUS"></span> <span
id="index-NO_005fLIST_005fAMBIGUOUS"></span> <span
id="index-LISTAMBIGUOUS"></span> <span
id="index-NOLISTAMBIGUOUS"></span> <span
id="index-ambiguous-completion"></span> <span
id="index-completion_002c-ambiguous"></span>

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.

<span id="index-LIST_005fBEEP"></span> <span
id="index-NO_005fLIST_005fBEEP"></span> <span
id="index-LISTBEEP"></span> <span id="index-NOLISTBEEP"></span> <span
id="index-beep_002c-ambiguous-completion"></span> <span
id="index-completion_002c-beep-on-ambiguous"></span>

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.

<span id="index-LIST_005fPACKED"></span> <span
id="index-NO_005fLIST_005fPACKED"></span> <span
id="index-LISTPACKED"></span> <span id="index-NOLISTPACKED"></span>
<span id="index-completion_002c-listing"></span>

LIST_PACKED

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

<span id="index-LIST_005fROWS_005fFIRST"></span> <span
id="index-NO_005fLIST_005fROWS_005fFIRST"></span> <span
id="index-LISTROWSFIRST"></span> <span
id="index-NOLISTROWSFIRST"></span> <span
id="index-completion_002c-listing-order"></span>

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.

<span id="index-LIST_005fTYPES"></span> <span
id="index-NO_005fLIST_005fTYPES"></span> <span
id="index-LISTTYPES"></span> <span id="index-NOLISTTYPES"></span> <span
id="index-marking-file-types"></span> <span
id="index-files_002c-marking-type-of"></span>

LIST_TYPES (-X) \<D>

When listing files that are possible completions, show the type of each
file with a trailing identifying mark.

<span id="index-MENU_005fCOMPLETE"></span> <span
id="index-NO_005fMENU_005fCOMPLETE"></span> <span
id="index-MENUCOMPLETE"></span> <span id="index-NOMENUCOMPLETE"></span>
<span id="index-completion_002c-menu-1"></span>

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.

<span id="index-REC_005fEXACT"></span> <span
id="index-NO_005fREC_005fEXACT"></span> <span
id="index-RECEXACT"></span> <span id="index-NORECEXACT"></span> <span
id="index-completion_002c-exact-matches"></span>

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.

------------------------------------------------------------------------

<span id="Expansion-and-Globbing"></span>

### 16.2.3 Expansion and Globbing

<span id="index-BAD_005fPATTERN"></span> <span
id="index-NO_005fBAD_005fPATTERN"></span> <span
id="index-BADPATTERN"></span> <span id="index-NOBADPATTERN"></span>
<span id="index-globbing_002c-bad-pattern"></span> <span
id="index-filename-generation_002c-bad-pattern"></span>

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.)

<span id="index-BARE_005fGLOB_005fQUAL"></span> <span
id="index-NO_005fBARE_005fGLOB_005fQUAL"></span> <span
id="index-BAREGLOBQUAL"></span> <span id="index-NOBAREGLOBQUAL"></span>
<span id="index-globbing-qualifiers_002c-enable"></span> <span
id="index-enable-globbing-qualifiers"></span>

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
[Filename Generation](Expansion.html#Filename-Generation).

<span id="index-BRACE_005fCCL"></span> <span
id="index-NO_005fBRACE_005fCCL"></span> <span
id="index-BRACECCL"></span> <span id="index-NOBRACECCL"></span> <span
id="index-brace-expansion_002c-extending"></span> <span
id="index-expansion_002c-brace_002c-extending"></span>

BRACE_CCL

Expand expressions in braces which would not otherwise undergo brace
expansion to a lexically ordered list of all the characters. See [Brace
Expansion](Expansion.html#Brace-Expansion).

<span id="index-CASE_005fGLOB"></span> <span
id="index-NO_005fCASE_005fGLOB"></span> <span
id="index-CASEGLOB"></span> <span id="index-NOCASEGLOB"></span> <span
id="index-case_002dinsensitive-globbing_002c-option"></span>

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).

<span id="index-CASE_005fMATCH"></span> <span
id="index-NO_005fCASE_005fMATCH"></span> <span
id="index-CASEMATCH"></span> <span id="index-NOCASEMATCH"></span> <span
id="index-case_002dinsensitive-regular-expression-matches_002c-option"></span>
<span
id="index-regular-expressions_002c-case_002dinsensitive-matching_002c-option"></span>

CASE_MATCH \<D>

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

<span id="index-CASE_005fPATHS"></span> <span
id="index-NO_005fCASE_005fPATHS"></span> <span
id="index-CASEPATHS"></span> <span id="index-NOCASEPATHS"></span> <span
id="index-case_002dsensitive-globbing_002c-option"></span>

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.

<span id="index-CSH_005fNULL_005fGLOB"></span> <span
id="index-NO_005fCSH_005fNULL_005fGLOB"></span> <span
id="index-CSHNULLGLOB"></span> <span id="index-NOCSHNULLGLOB"></span>
<span id="index-csh_002c-null-globbing-style"></span> <span
id="index-null-globbing-style_002c-csh"></span> <span
id="index-globbing_002c-null_002c-style_002c-csh"></span>

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.

<span id="index-EQUALS"></span> <span id="index-NO_005fEQUALS"></span>
<span id="index-NOEQUALS"></span> <span
id="index-filename-expansion_002c-_003d"></span>

EQUALS \<Z>

Perform = filename expansion. (See [Filename
Expansion](Expansion.html#Filename-Expansion).)

<span id="index-EXTENDED_005fGLOB"></span> <span
id="index-NO_005fEXTENDED_005fGLOB"></span> <span
id="index-EXTENDEDGLOB"></span> <span id="index-NOEXTENDEDGLOB"></span>
<span id="index-globbing_002c-extended"></span>

EXTENDED_GLOB

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

<span id="index-FORCE_005fFLOAT"></span> <span
id="index-NO_005fFORCE_005fFLOAT"></span> <span
id="index-FORCEFLOAT"></span> <span id="index-NOFORCEFLOAT"></span>
<span id="index-floating-point_002c-forcing-use-of"></span> <span
id="index-forcing-use-of-floating-point"></span>

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.

<span id="index-GLOB"></span> <span id="index-NO_005fGLOB"></span> <span
id="index-NOGLOB"></span> <span
id="index-globbing_002c-enabling"></span> <span
id="index-enabling-globbing"></span>

GLOB (+F, ksh: +f) \<D>

Perform filename generation (globbing). (See [Filename
Generation](Expansion.html#Filename-Generation).)

<span id="index-GLOB_005fASSIGN"></span> <span
id="index-NO_005fGLOB_005fASSIGN"></span> <span
id="index-GLOBASSIGN"></span> <span id="index-NOGLOBASSIGN"></span>

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.

<span id="index-GLOB_005fDOTS"></span> <span
id="index-NO_005fGLOB_005fDOTS"></span> <span
id="index-GLOBDOTS"></span> <span id="index-NOGLOBDOTS"></span> <span
id="index-globbing_002c-of-_002e-files"></span>

GLOB_DOTS (-4)

Do not require a leading ‘.’ in a filename to be matched explicitly.

<span id="index-GLOB_005fSTAR_005fSHORT"></span> <span
id="index-NO_005fGLOB_005fSTAR_005fSHORT"></span> <span
id="index-GLOBSTARSHORT"></span> <span
id="index-NOGLOBSTARSHORT"></span> <span
id="index-globbing_002c-short-forms"></span> <span
id="index-globbing_002c-_002a_002a-special"></span>

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.

<span id="index-GLOB_005fSUBST"></span> <span
id="index-NO_005fGLOB_005fSUBST"></span> <span
id="index-GLOBSUBST"></span> <span id="index-NOGLOBSUBST"></span>

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.

<span id="index-HIST_005fSUBST_005fPATTERN"></span> <span
id="index-NO_005fHIST_005fSUBST_005fPATTERN"></span> <span
id="index-HISTSUBSTPATTERN"></span> <span
id="index-NOHISTSUBSTPATTERN"></span>

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 [Modifiers](Expansion.html#Modifiers).

<span id="index-IGNORE_005fBRACES"></span> <span
id="index-NO_005fIGNORE_005fBRACES"></span> <span
id="index-IGNOREBRACES"></span> <span id="index-NOIGNOREBRACES"></span>
<span id="index-disabling-brace-expansion"></span> <span
id="index-brace-expansion_002c-disabling"></span> <span
id="index-expansion_002c-brace_002c-disabling"></span>

IGNORE_BRACES (-I) \<S>

Do not perform brace expansion. For historical reasons this also
includes the effect of the IGNORE_CLOSE_BRACES option.

<span id="index-IGNORE_005fCLOSE_005fBRACES"></span> <span
id="index-NO_005fIGNORE_005fCLOSE_005fBRACES"></span> <span
id="index-IGNORECLOSEBRACES"></span> <span
id="index-NOIGNORECLOSEBRACES"></span>

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:

<div class="example">

```zsh
args() { echo $# }
```

</div>

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

<div class="example">

```zsh
args() { echo $#; }
```

</div>

<span id="index-KSH_005fGLOB"></span> <span
id="index-NO_005fKSH_005fGLOB"></span> <span id="index-KSHGLOB"></span>
<span id="index-NOKSHGLOB"></span>

KSH_GLOB \<K>

In pattern matching, the interpretation of parentheses is affected by a
preceding ‘@’, ‘\*’, ‘+’, ‘?’ or ‘!’. See [Filename
Generation](Expansion.html#Filename-Generation).

<span id="index-MAGIC_005fEQUAL_005fSUBST"></span> <span
id="index-NO_005fMAGIC_005fEQUAL_005fSUBST"></span> <span
id="index-MAGICEQUALSUBST"></span> <span
id="index-NOMAGICEQUALSUBST"></span>

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.

<span id="index-MARK_005fDIRS"></span> <span
id="index-NO_005fMARK_005fDIRS"></span> <span
id="index-MARKDIRS"></span> <span id="index-NOMARKDIRS"></span> <span
id="index-directories_002c-marking"></span> <span
id="index-marking-directories"></span>

MARK_DIRS (-8, ksh: -X)

Append a trailing ‘/’ to all directory names resulting from filename
generation (globbing).

<span id="index-MULTIBYTE"></span> <span
id="index-NO_005fMULTIBYTE"></span> <span id="index-NOMULTIBYTE"></span>
<span
id="index-characters_002c-multibyte_002c-in-expansion-and-globbing"></span>
<span
id="index-multibyte-characters_002c-in-expansion-and-globbing"></span>

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.

<span id="index-NOMATCH"></span> <span id="index-NO_005fNOMATCH"></span>
<span id="index-NONOMATCH"></span> <span
id="index-globbing_002c-no-matches"></span>

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 ‘=’.

<span id="index-NULL_005fGLOB"></span> <span
id="index-NO_005fNULL_005fGLOB"></span> <span
id="index-NULLGLOB"></span> <span id="index-NONULLGLOB"></span> <span
id="index-globbing_002c-no-matches-1"></span>

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.

<span id="index-NUMERIC_005fGLOB_005fSORT"></span> <span
id="index-NO_005fNUMERIC_005fGLOB_005fSORT"></span> <span
id="index-NUMERICGLOBSORT"></span> <span
id="index-NONUMERICGLOBSORT"></span> <span
id="index-globbing_002c-sorting-numerically"></span>

NUMERIC_GLOB_SORT

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

<span id="index-RC_005fEXPAND_005fPARAM"></span> <span
id="index-NO_005fRC_005fEXPAND_005fPARAM"></span> <span
id="index-RCEXPANDPARAM"></span> <span
id="index-NORCEXPANDPARAM"></span> <span
id="index-rc_002c-parameter-expansion-style"></span> <span
id="index-parameter-expansion-style_002c-rc"></span>

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.

<span id="index-REMATCH_005fPCRE"></span> <span
id="index-NO_005fREMATCH_005fPCRE"></span> <span
id="index-REMATCHPCRE"></span> <span id="index-NOREMATCHPCRE"></span>
<span id="index-regexp_002c-PCRE"></span> <span
id="index-PCRE_002c-regexp"></span>

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.

<span id="index-SH_005fGLOB"></span> <span
id="index-NO_005fSH_005fGLOB"></span> <span id="index-SHGLOB"></span>
<span id="index-NOSHGLOB"></span> <span
id="index-sh_002c-globbing-style"></span> <span
id="index-globbing-style_002c-sh"></span>

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.

<span id="index-UNSET"></span> <span id="index-NO_005fUNSET"></span>
<span id="index-NOUNSET"></span> <span
id="index-parameters_002c-substituting-unset"></span> <span
id="index-unset-parameters_002c-substituting"></span>

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.

<span id="index-WARN_005fCREATE_005fGLOBAL"></span> <span
id="index-NO_005fWARN_005fCREATE_005fGLOBAL"></span> <span
id="index-WARNCREATEGLOBAL"></span> <span
id="index-NOWARNCREATEGLOBAL"></span> <span
id="index-parameters_002c-warning-when-created-globally"></span>

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.

<span id="index-WARN_005fNESTED_005fVAR"></span> <span
id="index-NO_005fWARN_005fNESTED_005fVAR"></span> <span
id="index-WARNNESTEDVAR"></span> <span
id="index-NO_005fWARNNESTEDVAR"></span> <span
id="index-parameters_002c-warning-when-setting-in-enclosing-scope"></span>

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

<div class="example">

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

</div>

------------------------------------------------------------------------

<span id="History"></span>

### 16.2.4 History

<span id="index-APPEND_005fHISTORY"></span> <span
id="index-NO_005fAPPEND_005fHISTORY"></span> <span
id="index-APPENDHISTORY"></span> <span
id="index-NOAPPENDHISTORY"></span> <span
id="index-history_002c-appending-to-a-file"></span>

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).

<span id="index-BANG_005fHIST"></span> <span
id="index-NO_005fBANG_005fHIST"></span> <span
id="index-BANGHIST"></span> <span id="index-NOBANGHIST"></span> <span
id="index-history_002c-enable-substitution"></span> <span
id="index-enable-history-substitution"></span>

BANG_HIST (+K) \<C> \<Z>

Perform textual history expansion, csh-style, treating the character ‘!’
specially.

<span id="index-EXTENDED_005fHISTORY"></span> <span
id="index-NO_005fEXTENDED_005fHISTORY"></span> <span
id="index-EXTENDEDHISTORY"></span> <span
id="index-NOEXTENDEDHISTORY"></span> <span
id="index-history_002c-timestamping"></span>

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>`’.

<span id="index-HIST_005fALLOW_005fCLOBBER"></span> <span
id="index-NO_005fHIST_005fALLOW_005fCLOBBER"></span> <span
id="index-HISTALLOWCLOBBER"></span> <span
id="index-NOHISTALLOWCLOBBER"></span>

HIST_ALLOW_CLOBBER

Add ‘\|’ to output redirections in the history. This allows history
references to clobber files even when CLOBBER is unset.

<span id="index-HIST_005fBEEP"></span> <span
id="index-NO_005fHIST_005fBEEP"></span> <span
id="index-HISTBEEP"></span> <span id="index-NOHISTBEEP"></span> <span
id="index-history-beeping"></span> <span
id="index-beep_002c-history"></span>

HIST_BEEP \<D>

Beep in ZLE when a widget attempts to access a history entry which isn’t
there.

<span id="index-HIST_005fEXPIRE_005fDUPS_005fFIRST"></span> <span
id="index-NO_005fHIST_005fEXPIRE_005fDUPS_005fFIRST"></span> <span
id="index-HISTEXPIREDUPSFIRST"></span> <span
id="index-NOHISTEXPIREDUPSFIRST"></span> <span
id="index-history_002c-expiring-duplicates"></span>

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.

<span id="index-HIST_005fFCNTL_005fLOCK"></span> <span
id="index-NO_005fHIST_005fFCNTL_005fLOCK"></span> <span
id="index-HISTFCNTLLOCK"></span> <span
id="index-NOHISTFCNTLLOCK"></span>

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.

<span id="index-HIST_005fFIND_005fNO_005fDUPS"></span> <span
id="index-NO_005fHIST_005fFIND_005fNO_005fDUPS"></span> <span
id="index-HISTFINDNODUPS"></span> <span
id="index-NOHISTFINDNODUPS"></span> <span
id="index-history_002c-ignoring-duplicates-in-search"></span>

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.

<span id="index-HIST_005fIGNORE_005fALL_005fDUPS"></span> <span
id="index-NO_005fHIST_005fIGNORE_005fALL_005fDUPS"></span> <span
id="index-HISTIGNOREALLDUPS"></span> <span
id="index-NOHISTIGNOREALLDUPS"></span> <span
id="index-history_002c-ignoring-all-duplicates"></span>

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).

<span id="index-HIST_005fIGNORE_005fDUPS"></span> <span
id="index-NO_005fHIST_005fIGNORE_005fDUPS"></span> <span
id="index-HISTIGNOREDUPS"></span> <span
id="index-NOHISTIGNOREDUPS"></span> <span
id="index-history_002c-ignoring-duplicates"></span>

HIST_IGNORE_DUPS (-h)

Do not enter command lines into the history list if they are duplicates
of the previous event.

<span id="index-HIST_005fIGNORE_005fSPACE"></span> <span
id="index-NO_005fHIST_005fIGNORE_005fSPACE"></span> <span
id="index-HISTIGNORESPACE"></span> <span
id="index-NOHISTIGNORESPACE"></span> <span
id="index-history_002c-ignoring-spaces"></span>

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.

<span id="index-HIST_005fLEX_005fWORDS"></span> <span
id="index-NO_005fHIST_005fLEX_005fWORDS"></span> <span
id="index-HISTLEXWORDS"></span> <span id="index-NOHISTLEXWORDS"></span>

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.

<span id="index-HIST_005fNO_005fFUNCTIONS"></span> <span
id="index-NO_005fHIST_005fNO_005fFUNCTIONS"></span> <span
id="index-HISTNOFUNCTIONS"></span> <span
id="index-NOHISTNOFUNCTIONS"></span>

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.

<span id="index-HIST_005fNO_005fSTORE"></span> <span
id="index-NO_005fHIST_005fNO_005fSTORE"></span> <span
id="index-HISTNOSTORE"></span> <span id="index-NOHISTNOSTORE"></span>

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.

<span id="index-HIST_005fREDUCE_005fBLANKS"></span> <span
id="index-NO_005fHIST_005fREDUCE_005fBLANKS"></span> <span
id="index-HISTREDUCEBLANKS"></span> <span
id="index-NOHISTREDUCEBLANKS"></span>

HIST_REDUCE_BLANKS

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

<span id="index-HIST_005fSAVE_005fBY_005fCOPY"></span> <span
id="index-NO_005fHIST_005fSAVE_005fBY_005fCOPY"></span> <span
id="index-HISTSAVEBYCOPY"></span> <span
id="index-NOHISTSAVEBYCOPY"></span>

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.

<span id="index-HIST_005fSAVE_005fNO_005fDUPS"></span> <span
id="index-NO_005fHIST_005fSAVE_005fNO_005fDUPS"></span> <span
id="index-HISTSAVENODUPS"></span> <span
id="index-NOHISTSAVENODUPS"></span>

HIST_SAVE_NO_DUPS

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

<span id="index-HIST_005fVERIFY"></span> <span
id="index-NO_005fHIST_005fVERIFY"></span> <span
id="index-HISTVERIFY"></span> <span id="index-NOHISTVERIFY"></span>
<span id="index-history_002c-verifying-substitution"></span>

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.

<span id="index-INC_005fAPPEND_005fHISTORY"></span> <span
id="index-NO_005fINC_005fAPPEND_005fHISTORY"></span> <span
id="index-INCAPPENDHISTORY"></span> <span
id="index-NOINCAPPENDHISTORY"></span> <span
id="index-history_002c-incremental-appending-to-a-file"></span>

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).

<span id="index-INC_005fAPPEND_005fHISTORY_005fTIME"></span> <span
id="index-NO_005fINC_005fAPPEND_005fHISTORY_005fTIME"></span> <span
id="index-INCAPPENDHISTORYTIME"></span> <span
id="index-NOINCAPPENDHISTORYTIME"></span> <span
id="index-history_002c-incremental-appending-to-a-file-with-time"></span>

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.

<span id="index-SHARE_005fHISTORY"></span> <span
id="index-NO_005fSHARE_005fHISTORY"></span> <span
id="index-SHAREHISTORY"></span> <span id="index-NOSHAREHISTORY"></span>
<span id="index-share-history"></span> <span
id="index-history_002c-sharing"></span>

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’.

------------------------------------------------------------------------

<span id="Initialisation"></span>

### 16.2.5 Initialisation

<span id="index-ALL_005fEXPORT"></span> <span
id="index-NO_005fALL_005fEXPORT"></span> <span
id="index-ALLEXPORT"></span> <span id="index-NOALLEXPORT"></span> <span
id="index-export_002c-automatic"></span>

ALL_EXPORT (-a, ksh: -a)

All parameters subsequently defined are automatically exported.

<span id="index-GLOBAL_005fEXPORT"></span> <span
id="index-NO_005fGLOBAL_005fEXPORT"></span> <span
id="index-GLOBALEXPORT"></span> <span id="index-NOGLOBALEXPORT"></span>
<span id="index-environment_002c-and-local-parameters"></span>

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

<span id="index-exporting_002c-and-local-parameters"></span> <span
id="index-GLOBAL_005fRCS"></span> <span
id="index-NO_005fGLOBAL_005fRCS"></span> <span
id="index-GLOBALRCS"></span> <span id="index-NOGLOBALRCS"></span> <span
id="index-startup-files_002c-global_002c-inhibiting"></span> <span
id="index-files_002c-global-startup_002c-inhibiting"></span>

GLOBAL_RCS (+d) \<D>

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

<span id="index-RCS"></span> <span id="index-NO_005fRCS"></span> <span
id="index-NORCS"></span> <span
id="index-startup-files_002c-sourcing"></span>

RCS (+f) \<D>

After /etc/zshenv is sourced on startup, source the .zshenv,
/etc/zprofile, .zprofile, /etc/zshrc, .zshrc, /etc/zlogin, .zlogin, and
.zlogout files, as described in [Files](Files.html#Files). If this
option is unset, the /etc/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.

------------------------------------------------------------------------

<span id="Input_002fOutput"></span>

### 16.2.6 Input/Output

<span id="index-ALIASES"></span> <span id="index-NO_005fALIASES"></span>
<span id="index-NOALIASES"></span> <span
id="index-aliases_002c-expansion"></span>

ALIASES \<D>

Expand aliases.

<span id="index-CLOBBER"></span> <span id="index-NO_005fCLOBBER"></span>
<span id="index-NOCLOBBER"></span> <span
id="index-clobbering_002c-of-files"></span> <span
id="index-file-clobbering_002c-allowing"></span>

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.

<span id="index-CLOBBER_005fEMPTY"></span> <span
id="index-NO_005fCLOBBER_005fEMPTY"></span> <span
id="index-CLOBBEREMPTY"></span> <span id="index-NOCLOBBEREMPTY"></span>
<span id="index-clobbering_002c-of-empty-files"></span> <span
id="index-file-clobbering_002c-of-empty-files"></span>

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.

<span id="index-CORRECT"></span> <span id="index-NO_005fCORRECT"></span>
<span id="index-NOCORRECT"></span> <span
id="index-correction_002c-spelling"></span> <span
id="index-spelling-correction"></span>

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.

<span id="index-CORRECT_005fALL"></span> <span
id="index-NO_005fCORRECT_005fALL"></span> <span
id="index-CORRECTALL"></span> <span id="index-NOCORRECTALL"></span>

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.

<span id="index-DVORAK"></span> <span id="index-NO_005fDVORAK"></span>
<span id="index-NODVORAK"></span>

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.

<span id="index-FLOW_005fCONTROL"></span> <span
id="index-NO_005fFLOW_005fCONTROL"></span> <span
id="index-FLOWCONTROL"></span> <span id="index-NOFLOWCONTROL"></span>
<span id="index-flow-control"></span>

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.

<span id="index-IGNORE_005fEOF"></span> <span
id="index-NO_005fIGNORE_005fEOF"></span> <span
id="index-IGNOREEOF"></span> <span id="index-NOIGNOREEOF"></span> <span
id="index-EOF_002c-ignoring"></span>

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.

<span id="index-INTERACTIVE_005fCOMMENTS"></span> <span
id="index-NO_005fINTERACTIVE_005fCOMMENTS"></span> <span
id="index-INTERACTIVECOMMENTS"></span> <span
id="index-NOINTERACTIVECOMMENTS"></span> <span
id="index-comments_002c-in-interactive-shells"></span>

INTERACTIVE_COMMENTS (-k) \<K> \<S>

Allow comments even in interactive shells.

<span id="index-HASH_005fCMDS"></span> <span
id="index-NO_005fHASH_005fCMDS"></span> <span
id="index-HASHCMDS"></span> <span id="index-NOHASHCMDS"></span> <span
id="index-hashing_002c-of-commands"></span> <span
id="index-command-hashing"></span>

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 reporting them as spelling errors.

<span id="index-HASH_005fDIRS"></span> <span
id="index-NO_005fHASH_005fDIRS"></span> <span
id="index-HASHDIRS"></span> <span id="index-NOHASHDIRS"></span> <span
id="index-hashing_002c-of-directories"></span> <span
id="index-directories_002c-hashing"></span>

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.

<span id="index-HASH_005fEXECUTABLES_005fONLY"></span> <span
id="index-NO_005fHASH_005fEXECUTABLES_005fONLY"></span> <span
id="index-HASHEXECUTABLESONLY"></span> <span
id="index-NOHASHEXECUTABLESONLY"></span>

HASH_EXECUTABLES_ONLY

When hashing commands because of HASH_CMDS, check that the 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.

<span id="index-MAIL_005fWARNING"></span> <span
id="index-NO_005fMAIL_005fWARNING"></span> <span
id="index-MAILWARNING"></span> <span id="index-NOMAILWARNING"></span>
<span id="index-mail_002c-warning-of-reading"></span>

MAIL_WARNING (-U)

Print a warning message if a mail file has been accessed since the shell
last checked.

<span id="index-PATH_005fDIRS"></span> <span
id="index-NO_005fPATH_005fDIRS"></span> <span
id="index-PATHDIRS"></span> <span id="index-NOPATHDIRS"></span> <span
id="index-path-search_002c-extended"></span>

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 indicated by this option, and regardless of whether ‘.’ or the
current directory appear in the command search path.

<span id="index-PATH_005fSCRIPT"></span> <span
id="index-NO_005fPATH_005fSCRIPT"></span> <span
id="index-PATHSCRIPT"></span> <span id="index-NOPATHSCRIPT"></span>
<span id="index-path-search_002c-for-script-argument-to-shell"></span>

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 [Invocation](Invocation.html#Invocation).

<span id="index-PRINT_005fEIGHT_005fBIT"></span> <span
id="index-NO_005fPRINT_005fEIGHT_005fBIT"></span> <span
id="index-PRINTEIGHTBIT"></span> <span
id="index-NOPRINTEIGHTBIT"></span> <span
id="index-eight-bit-characters_002c-printing"></span>

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)).

<span id="index-PRINT_005fEXIT_005fVALUE"></span> <span
id="index-NO_005fPRINT_005fEXIT_005fVALUE"></span> <span
id="index-PRINTEXITVALUE"></span> <span
id="index-NOPRINTEXITVALUE"></span> <span
id="index-exit-status_002c-printing"></span>

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.

<span id="index-RC_005fQUOTES"></span> <span
id="index-NO_005fRC_005fQUOTES"></span> <span
id="index-RCQUOTES"></span> <span id="index-NORCQUOTES"></span> <span
id="index-rc_002c-quoting-style"></span> <span
id="index-quoting-style_002c-rc"></span>

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.

<span id="index-RM_005fSTAR_005fSILENT"></span> <span
id="index-NO_005fRM_005fSTAR_005fSILENT"></span> <span
id="index-RMSTARSILENT"></span> <span id="index-NORMSTARSILENT"></span>
<span id="index-rm-_002a_002c-querying-before"></span> <span
id="index-querying-before-rm-_002a"></span>

RM_STAR_SILENT (-H) \<K> \<S>

Do not query the user before executing ‘rm \*’ or ‘rm path/\*’.

<span id="index-RM_005fSTAR_005fWAIT"></span> <span
id="index-NO_005fRM_005fSTAR_005fWAIT"></span> <span
id="index-RMSTARWAIT"></span> <span id="index-NORMSTARWAIT"></span>
<span id="index-rm-_002a_002c-waiting-before"></span> <span
id="index-waiting-before-rm-_002a"></span>

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).

<span id="index-SHORT_005fLOOPS"></span> <span
id="index-NO_005fSHORT_005fLOOPS"></span> <span
id="index-SHORTLOOPS"></span> <span id="index-NOSHORTLOOPS"></span>

SHORT_LOOPS \<C> \<Z>

Allow the short forms of for, repeat, select, if, and function
constructs.

<span id="index-SHORT_005fREPEAT"></span> <span
id="index-NO_005fSHORT_005fREPEAT"></span> <span
id="index-SHORTREPEAT"></span> <span id="index-NOSHORTREPEAT"></span>

SHORT_REPEAT

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

<span id="index-SUN_005fKEYBOARD_005fHACK"></span> <span
id="index-NO_005fSUN_005fKEYBOARD_005fHACK"></span> <span
id="index-SUNKEYBOARDHACK"></span> <span
id="index-NOSUNKEYBOARDHACK"></span> <span
id="index-sun-keyboard_002c-annoying"></span> <span
id="index-annoying-keyboard_002c-sun"></span>

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.

------------------------------------------------------------------------

<span id="Job-Control"></span>

### 16.2.7 Job Control

<span id="index-AUTO_005fCONTINUE"></span> <span
id="index-NO_005fAUTO_005fCONTINUE"></span> <span
id="index-AUTOCONTINUE"></span> <span id="index-NOAUTOCONTINUE"></span>
<span id="index-jobs_002c-continuing-automatically"></span> <span
id="index-continuing-jobs-automatically"></span>

AUTO_CONTINUE

with the disown builtin command are automatically sent a CONT signal to
make them running.

<span id="index-AUTO_005fRESUME"></span> <span
id="index-NO_005fAUTO_005fRESUME"></span> <span
id="index-AUTORESUME"></span> <span id="index-NOAUTORESUME"></span>
<span id="index-jobs_002c-resuming-automatically"></span> <span
id="index-resuming-jobs-automatically"></span>

AUTO_RESUME (-W)

Treat single word simple commands without redirection as candidates for
resumption of an existing job.

<span id="index-BG_005fNICE"></span> <span
id="index-NO_005fBG_005fNICE"></span> <span id="index-BGNICE"></span>
<span id="index-NOBGNICE"></span> <span
id="index-jobs_002c-background-priority"></span> <span
id="index-background-jobs_002c-priority-of"></span> <span
id="index-priority-of-background-jobs"></span>

BG_NICE (-6) \<C> \<Z>

Run all background jobs at a lower priority. This option is set by
default.

<span id="index-CHECK_005fJOBS"></span> <span
id="index-NO_005fCHECK_005fJOBS"></span> <span
id="index-CHECKJOBS"></span> <span id="index-NOCHECKJOBS"></span> <span
id="index-exiting_002c-checking-jobs-when"></span> <span
id="index-logging-out_002c-checking-jobs-when"></span>

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
[Functions](Functions.html#Functions) is not counted for this purpose.

<span id="index-CHECK_005fRUNNING_005fJOBS"></span> <span
id="index-NO_005fCHECK_005fRUNNING_005fJOBS"></span> <span
id="index-CHECKRUNNINGJOBS"></span> <span
id="index-NOCHECKRUNNINGJOBS"></span> <span
id="index-exiting_002c-checking-running-jobs-when"></span> <span
id="index-logging-out_002c-checking-running-jobs-when"></span>

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.

<span id="index-HUP"></span> <span id="index-NO_005fHUP"></span> <span
id="index-NOHUP"></span> <span id="index-jobs_002c-HUP"></span>

HUP \<Z>

Send the HUP signal to running jobs when the shell exits.

<span id="index-LONG_005fLIST_005fJOBS"></span> <span
id="index-NO_005fLONG_005fLIST_005fJOBS"></span> <span
id="index-LONGLISTJOBS"></span> <span id="index-NOLONGLISTJOBS"></span>
<span id="index-jobs_002c-list-format"></span>

LONG_LIST_JOBS (-R)

Print job notifications in the long format by default.

<span id="index-MONITOR"></span> <span id="index-NO_005fMONITOR"></span>
<span id="index-NOMONITOR"></span> <span
id="index-job-control_002c-allowing"></span>

MONITOR (-m, ksh: -m)

Allow job control. Set by default in interactive shells.

<span id="index-NOTIFY"></span> <span id="index-NO_005fNOTIFY"></span>
<span id="index-NONOTIFY"></span> <span
id="index-background-jobs_002c-notification"></span> <span
id="index-notification-of-background-jobs"></span>

NOTIFY (-5, ksh: -b) \<Z>

Report the status of background jobs immediately, rather than waiting
until just before printing a prompt.

<span id="index-POSIX_005fJOBS"></span> <span
id="index-POSIXJOBS"></span> <span
id="index-NO_005fPOSIX_005fJOBS"></span> <span
id="index-NOPOSIXJOBS"></span> <span
id="index-bg_002c-output-in-POSIX-format"></span> <span
id="index-fg_002c-output-in-POSIX-format"></span> <span
id="index-job-control_002c-in-subshell"></span> <span
id="index-jobs_002c-output-in-subshell"></span>

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.

------------------------------------------------------------------------

<span id="Prompting"></span>

### 16.2.8 Prompting

<span id="index-PROMPT_005fBANG"></span> <span
id="index-NO_005fPROMPT_005fBANG"></span> <span
id="index-PROMPTBANG"></span> <span id="index-NOPROMPTBANG"></span>
<span id="index-prompt_002c-_0021-expansion"></span>

PROMPT_BANG \<K>

If set, ‘!’ is treated specially in prompt expansion. See [Prompt
Expansion](Prompt-Expansion.html#Prompt-Expansion).

<span id="index-PROMPT_005fCR"></span> <span
id="index-NO_005fPROMPT_005fCR"></span> <span
id="index-PROMPTCR"></span> <span id="index-NOPROMPTCR"></span> <span
id="index-prompt_002c-with-CR"></span>

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.

<span id="index-PROMPT_005fSP"></span> <span
id="index-NO_005fPROMPT_005fSP"></span> <span
id="index-PROMPTSP"></span> <span id="index-NOPROMPTSP"></span> <span
id="index-prompt_002c-save-partial-lines"></span>

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.

<span id="index-PROMPT_005fPERCENT"></span> <span
id="index-NO_005fPROMPT_005fPERCENT"></span> <span
id="index-PROMPTPERCENT"></span> <span
id="index-NOPROMPTPERCENT"></span> <span
id="index-prompt_002c-_0025-expansion"></span>

PROMPT_PERCENT \<C> \<Z>

If set, ‘%’ is treated specially in prompt expansion. See [Prompt
Expansion](Prompt-Expansion.html#Prompt-Expansion).

<span id="index-PROMPT_005fSUBST"></span> <span
id="index-NO_005fPROMPT_005fSUBST"></span> <span
id="index-PROMPTSUBST"></span> <span id="index-NOPROMPTSUBST"></span>
<span id="index-prompt_002c-parameter-expansion"></span>

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.

<span id="index-TRANSIENT_005fRPROMPT"></span> <span
id="index-NO_005fTRANSIENT_005fRPROMPT"></span> <span
id="index-TRANSIENTRPROMPT"></span> <span
id="index-NOTRANSIENTRPROMPT"></span>

TRANSIENT_RPROMPT

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

------------------------------------------------------------------------

<span id="Scripts-and-Functions"></span>

### 16.2.9 Scripts and Functions

<span id="index-ALIAS_005fFUNC_005fDEF"></span> <span
id="index-NO_005fALIAS_005fFUNC_005fDEF"></span> <span
id="index-ALIASFUNCDEF"></span> <span id="index-NOALIASFUNCDEF"></span>
<span id="index-functions_002c-defining-with-expanded-aliases"></span>
<span id="index-aliases_002c-expanding-in-function-definition"></span>

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.

<div class="example">

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

</div>

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.

<span id="index-C_005fBASES"></span> <span
id="index-NO_005fC_005fBASES"></span> <span id="index-CBASES"></span>
<span id="index-NOCBASES"></span> <span
id="index-bases_002c-output-in-C-format"></span> <span
id="index-hexadecimal_002c-output-in-C-format"></span> <span
id="index-octal_002c-output-in-C-format"></span>

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.

<span id="index-C_005fPRECEDENCES"></span> <span
id="index-NO_005fC_005fPRECEDENCES"></span> <span
id="index-CPRECEDENCES"></span> <span id="index-NOCPRECEDENCES"></span>
<span id="index-precedence_002c-operator"></span> <span
id="index-operator-precedence"></span>

C_PRECEDENCES

This alters the precedence of arithmetic operators to be more like C and
other programming languages; [Arithmetic
Evaluation](Arithmetic-Evaluation.html#Arithmetic-Evaluation) has an
explicit list.

<span id="index-DEBUG_005fBEFORE_005fCMD"></span> <span
id="index-NO_005fDEBUG_005fBEFORE_005fCMD"></span> <span
id="index-DEBUGBEFORECMD"></span> <span
id="index-NODEBUGBEFORECMD"></span> <span
id="index-traps_002c-DEBUG_002c-before-or-after-command"></span> <span
id="index-DEBUG-trap_002c-before-or-after-command"></span>

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.

<span id="index-ERR_005fEXIT"></span> <span
id="index-NO_005fERR_005fEXIT"></span> <span id="index-ERREXIT"></span>
<span id="index-NOERREXIT"></span> <span
id="index-exit-status_002c-trapping"></span>

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

<div class="example">

```zsh
false && true
```

</div>

does not trigger exit.

Exiting due to ERR_EXIT has certain interactions with asynchronous jobs
noted in [Jobs & Signals](Jobs-_0026-Signals.html#Jobs-_0026-Signals).

<span id="index-ERR_005fRETURN"></span> <span
id="index-NO_005fERR_005fRETURN"></span> <span
id="index-ERRRETURN"></span> <span id="index-NOERRRETURN"></span> <span
id="index-function-return_002c-on-error"></span> <span
id="index-return-from-function_002c-on-error"></span>

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:

<div class="example">

```zsh
summit || true
```

</div>

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.

<span id="index-EVAL_005fLINENO"></span> <span
id="index-NO_005fEVAL_005fLINENO"></span> <span
id="index-EVALLINENO"></span> <span id="index-NOEVALLINENO"></span>
<span id="index-line-number_002c-in-evaluated-expression"></span>

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.

<span id="index-EXEC"></span> <span id="index-NO_005fEXEC"></span> <span
id="index-NOEXEC"></span> <span
id="index-command-execution_002c-enabling"></span>

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.

<span id="index-FUNCTION_005fARGZERO"></span> <span
id="index-NO_005fFUNCTION_005fARGZERO"></span> <span
id="index-FUNCTIONARGZERO"></span> <span
id="index-NOFUNCTIONARGZERO"></span> <span
id="index-_00240_002c-setting"></span>

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.

<span id="index-LOCAL_005fLOOPS"></span> <span
id="index-NO_005fLOCAL_005fLOOPS"></span> <span
id="index-LOCALLOOPS"></span> <span id="index-NOLOCALLOOPS"></span>
<span id="index-break_002c-inside-function"></span> <span
id="index-continue_002c-inside-function"></span> <span
id="index-function_002c-scope-of-break-and-continue"></span>

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.

<span id="index-LOCAL_005fOPTIONS"></span> <span
id="index-NO_005fLOCAL_005fOPTIONS"></span> <span
id="index-LOCALOPTIONS"></span> <span id="index-NOLOCALOPTIONS"></span>

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.

<span id="index-LOCAL_005fPATTERNS"></span> <span
id="index-NO_005fLOCAL_005fPATTERNS"></span> <span
id="index-LOCALPATTERNS"></span> <span
id="index-NOLOCALPATTERNS"></span>

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.

<span id="index-LOCAL_005fTRAPS"></span> <span
id="index-NO_005fLOCAL_005fTRAPS"></span> <span
id="index-LOCALTRAPS"></span> <span id="index-NOLOCALTRAPS"></span>

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,

<div class="example">

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

</div>

will restore normal handling of SIGINT after the function exits.

<span id="index-MULTI_005fFUNC_005fDEF"></span> <span
id="index-NO_005fMULTI_005fFUNC_005fDEF"></span> <span
id="index-MULTIFUNCDEF"></span> <span id="index-NOMULTIFUNCDEF"></span>

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.

<span id="index-MULTIOS"></span> <span id="index-NO_005fMULTIOS"></span>
<span id="index-NOMULTIOS"></span>

MULTIOS \<Z>

Perform implicit tees or cats when multiple redirections are attempted
(see [Redirection](Redirection.html#Redirection)).

<span id="index-OCTAL_005fZEROES"></span> <span
id="index-NO_005fOCTAL_005fZEROES"></span> <span
id="index-OCTALZEROES"></span> <span id="index-NOOCTALZEROES"></span>
<span id="index-octal_002c-arithmetic-expressions"></span>

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.

<span id="index-PIPE_005fFAIL"></span> <span
id="index-NO_005fPIPE_005fFAIL"></span> <span
id="index-PIPEFAIL"></span> <span id="index-NOPIPEFAIL"></span> <span
id="index-exit-status-from-pipeline"></span> <span
id="index-status_002c-on-exit-from-pipeline"></span> <span
id="index-pipeline_002c-exit-status-from"></span>

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.

<span id="index-SOURCE_005fTRACE"></span> <span
id="index-NO_005fSOURCE_005fTRACE"></span> <span
id="index-SOURCETRACE"></span> <span id="index-NOSOURCETRACE"></span>

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.

<span id="index-TYPESET_005fSILENT"></span> <span
id="index-NO_005fTYPESET_005fSILENT"></span> <span
id="index-TYPESETSILENT"></span> <span
id="index-NOTYPESETSILENT"></span>

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.

<span id="index-TYPESET_005fTO_005fUNSET"></span> <span
id="index-NO_005fTYPESET_005fTO_005fUNSET"></span> <span
id="index-TYPESETTOUNSET"></span> <span
id="index-NOTYPESETTOUNSET"></span>

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 explicity assigned to it, either in the ‘typeset’ command itself or
as a later assignment statement.

<span id="index-VERBOSE"></span> <span id="index-NO_005fVERBOSE"></span>
<span id="index-NOVERBOSE"></span> <span
id="index-tracing_002c-of-input-lines"></span> <span
id="index-input_002c-tracing"></span>

VERBOSE (-v, ksh: -v)

Print shell input lines as they are read.

<span id="index-XTRACE"></span> <span id="index-NO_005fXTRACE"></span>
<span id="index-NOXTRACE"></span> <span
id="index-tracing_002c-of-commands"></span> <span
id="index-commands_002c-tracing"></span>

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 [Prompt
Expansion](Prompt-Expansion.html#Prompt-Expansion).

------------------------------------------------------------------------

<span id="Shell-Emulation"></span>

### 16.2.10 Shell Emulation

<span id="index-APPEND_005fCREATE"></span> <span
id="index-NO_005fAPPEND_005fCREATE"></span> <span
id="index-APPENDCREATE"></span> <span id="index-NOAPPENDCREATE"></span>
<span id="index-clobbering_002c-POSIX-compatibility"></span> <span
id="index-file-clobbering_002c-POSIX-compatibility"></span> <span
id="index-no-clobber_002c-POSIX-compatible"></span>

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).

<span id="index-BASH_005fREMATCH"></span> <span
id="index-NO_005fBASH_005fREMATCH"></span> <span
id="index-BASHREMATCH"></span> <span id="index-NOBASHREMATCH"></span>
<span id="index-bash_002c-BASH_005fREMATCH-variable"></span> <span
id="index-regexp_002c-bash-BASH_005fREMATCH-variable"></span>

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.

<span id="index-BSD_005fECHO"></span> <span
id="index-NO_005fBSD_005fECHO"></span> <span id="index-BSDECHO"></span>
<span id="index-NOBSDECHO"></span> <span
id="index-echo_002c-BSD-compatible"></span>

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.

<span id="index-CONTINUE_005fON_005fERROR"></span> <span
id="index-NO_005fCONTINUE_005fON_005fERROR"></span> <span
id="index-CONTINUEONERROR"></span> <span
id="index-NOCONTINUEONERROR"></span> <span
id="index-error_002c-option-to-continue-script-on"></span>

CONTINUE_ON_ERROR

If a fatal error is encountered (see
[Errors](Shell-Grammar.html#Errors)), 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.

<span id="index-CSH_005fJUNKIE_005fHISTORY"></span> <span
id="index-NO_005fCSH_005fJUNKIE_005fHISTORY"></span> <span
id="index-CSHJUNKIEHISTORY"></span> <span
id="index-NOCSHJUNKIEHISTORY"></span> <span
id="index-csh_002c-history-style"></span> <span
id="index-history-style_002c-csh"></span>

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.

<span id="index-CSH_005fJUNKIE_005fLOOPS"></span> <span
id="index-NO_005fCSH_005fJUNKIE_005fLOOPS"></span> <span
id="index-CSHJUNKIELOOPS"></span> <span
id="index-NOCSHJUNKIELOOPS"></span> <span
id="index-csh_002c-loop-style"></span> <span
id="index-loop-style_002c-csh"></span>

CSH_JUNKIE_LOOPS \<C>

Allow loop bodies to take the form ‘`list`; end’ instead of ‘do `list`;
done’.

<span id="index-CSH_005fJUNKIE_005fQUOTES"></span> <span
id="index-NO_005fCSH_005fJUNKIE_005fQUOTES"></span> <span
id="index-CSHJUNKIEQUOTES"></span> <span
id="index-NOCSHJUNKIEQUOTES"></span> <span
id="index-csh_002c-quoting-style"></span> <span
id="index-quoting-style_002c-csh"></span>

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.

<span id="index-CSH_005fNULLCMD"></span> <span
id="index-NO_005fCSH_005fNULLCMD"></span> <span
id="index-CSHNULLCMD"></span> <span id="index-NOCSHNULLCMD"></span>
<span id="index-NULLCMD_002c-ignoring"></span> <span
id="index-READNULLCMD_002c-ignoring"></span> <span
id="index-redirections-with-no-command_002c-csh"></span> <span
id="index-csh_002c-redirections-with-no-command"></span>

CSH_NULLCMD \<C>

Do not use the values of NULLCMD and READNULLCMD when running
redirections with no command. This make such redirections fail (see
[Redirection](Redirection.html#Redirection)).

<span id="index-KSH_005fARRAYS"></span> <span
id="index-NO_005fKSH_005fARRAYS"></span> <span
id="index-KSHARRAYS"></span> <span id="index-NOKSHARRAYS"></span> <span
id="index-arrays_002c-ksh-style"></span> <span
id="index-array-style_002c-ksh"></span> <span
id="index-ksh_002c-array-style"></span>

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’).

<span id="index-KSH_005fAUTOLOAD"></span> <span
id="index-NO_005fKSH_005fAUTOLOAD"></span> <span
id="index-KSHAUTOLOAD"></span> <span id="index-NOKSHAUTOLOAD"></span>

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.)

<span id="index-KSH_005fOPTION_005fPRINT"></span> <span
id="index-NO_005fKSH_005fOPTION_005fPRINT"></span> <span
id="index-KSHOPTIONPRINT"></span> <span
id="index-NOKSHOPTIONPRINT"></span> <span
id="index-option-printing_002c-ksh-style"></span> <span
id="index-option-printing-style_002c-ksh"></span> <span
id="index-ksh_002c-option-printing-style"></span>

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.

<span id="index-KSH_005fTYPESET"></span> <span
id="index-NO_005fKSH_005fTYPESET"></span> <span
id="index-KSHTYPESET"></span> <span id="index-NOKSHTYPESET"></span>
<span id="index-argument-splitting_002c-in-typeset-etc_002e"></span>
<span id="index-ksh_002c-argument-splitting-in-typeset"></span>

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.

<span id="index-KSH_005fZERO_005fSUBSCRIPT"></span> <span
id="index-NO_005fKSH_005fZERO_005fSUBSCRIPT"></span> <span
id="index-KSHZEROSUBSCRIPT"></span> <span
id="index-NOKSHZEROSUBSCRIPT"></span> <span
id="index-arrays_002c-behaviour-of-index-zero"></span>

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,

<div class="example">

```zsh
array[0]=(element)
```

</div>

is an error, while

<div class="example">

```zsh
array[0,1]=(element)
```

</div>

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.

<span id="index-POSIX_005fALIASES"></span> <span
id="index-NO_005fPOSIX_005fALIASES"></span> <span
id="index-POSIXALIASES"></span> <span id="index-NOPOSIXALIASES"></span>

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
[Reserved Words](Shell-Grammar.html#Reserved-Words).

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.

<span id="index-POSIX_005fARGZERO"></span> <span
id="index-NO_005fPOSIX_005fARGZERO"></span> <span
id="index-POSIXARGZERO"></span> <span id="index-NOPOSIXARGZERO"></span>
<span id="index-_00240_002c-using"></span>

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:

<div class="example">

```zsh
emulate sh -o POSIX_ARGZERO
```

</div>

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

<span id="index-POSIX_005fBUILTINS"></span> <span
id="index-NO_005fPOSIX_005fBUILTINS"></span> <span
id="index-POSIXBUILTINS"></span> <span
id="index-NOPOSIXBUILTINS"></span>

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.

<span id="index-POSIX_005fIDENTIFIERS"></span> <span
id="index-NO_005fPOSIX_005fIDENTIFIERS"></span> <span
id="index-POSIXIDENTIFIERS"></span> <span
id="index-NOPOSIXIDENTIFIERS"></span>

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 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.

<span id="index-POSIX_005fSTRINGS"></span> <span
id="index-NO_005fPOSIX_005fSTRINGS"></span> <span
id="index-POSIXSTRINGS"></span> <span id="index-NOPOSIXSTRINGS"></span>
<span
id="index-discarding-embedded-nulls-in-_0024_0027_002e_002e_002e_0027"></span>
<span
id="index-embedded-nulls_002c-in-_0024_0027_002e_002e_002e_0027"></span>
<span
id="index-nulls_002c-embedded-in-_0024_0027_002e_002e_002e_0027"></span>

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

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.

<span id="index-POSIX_005fTRAPS"></span> <span
id="index-NO_005fPOSIX_005fTRAPS"></span> <span
id="index-POSIXTRAPS"></span> <span id="index-NOPOSIXTRAPS"></span>
<span id="index-traps_002c-on-function-exit"></span> <span
id="index-traps_002c-POSIX-compatibility"></span>

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.

<span id="index-SH_005fFILE_005fEXPANSION"></span> <span
id="index-NO_005fSH_005fFILE_005fEXPANSION"></span> <span
id="index-SHFILEEXPANSION"></span> <span
id="index-NOSHFILEEXPANSION"></span> <span
id="index-sh_002c-expansion-style"></span> <span
id="index-expansion-style_002c-sh"></span>

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.

<span id="index-SH_005fNULLCMD"></span> <span
id="index-NO_005fSH_005fNULLCMD"></span> <span
id="index-SHNULLCMD"></span> <span id="index-NOSHNULLCMD"></span> <span
id="index-NULLCMD_002c-ignoring-1"></span> <span
id="index-READNULLCMD_002c-ignoring-1"></span> <span
id="index-sh_002c-redirections-with-no-command"></span> <span
id="index-ksh_002c-redirections-with-no-command"></span> <span
id="index-redirections-with-no-command_002c-sh"></span> <span
id="index-redirections-with-no-command_002c-ksh"></span>

SH_NULLCMD \<K> \<S>

Do not use the values of NULLCMD and READNULLCMD when doing
redirections, use ‘:’ instead (see
[Redirection](Redirection.html#Redirection)).

<span id="index-SH_005fOPTION_005fLETTERS"></span> <span
id="index-NO_005fSH_005fOPTION_005fLETTERS"></span> <span
id="index-SHOPTIONLETTERS"></span> <span
id="index-NOSHOPTIONLETTERS"></span> <span
id="index-sh_002c-single-letter-options-style"></span> <span
id="index-ksh_002c-single-letter-options-style"></span> <span
id="index-single-letter-options_002c-ksh-style"></span> <span
id="index-options_002c-single-letter_002c-ksh-style"></span>

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.

<span id="index-SH_005fWORD_005fSPLIT"></span> <span
id="index-NO_005fSH_005fWORD_005fSPLIT"></span> <span
id="index-SHWORDSPLIT"></span> <span id="index-NOSHWORDSPLIT"></span>
<span id="index-field-splitting_002c-sh-style"></span> <span
id="index-sh_002c-field-splitting-style"></span>

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
[Parameter Expansion](Expansion.html#Parameter-Expansion).)

<span id="index-TRAPS_005fASYNC"></span> <span
id="index-NO_005fTRAPS_005fASYNC"></span> <span
id="index-TRAPSASYNC"></span> <span id="index-NOTRAPSASYNC"></span>
<span id="index-traps_002c-asynchronous"></span>

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.

------------------------------------------------------------------------

<span id="Shell-State"></span>

### 16.2.11 Shell State

<span id="index-INTERACTIVE"></span> <span
id="index-NO_005fINTERACTIVE"></span> <span
id="index-NOINTERACTIVE"></span>

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.

<span id="index-LOGIN"></span> <span id="index-NO_005fLOGIN"></span>
<span id="index-NOLOGIN"></span>

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 ‘-’.

<span id="index-PRIVILEGED"></span> <span
id="index-NO_005fPRIVILEGED"></span> <span
id="index-NOPRIVILEGED"></span> <span id="index-privileged-mode"></span>
<span id="index-mode_002c-privileged"></span>

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.

<div class="example">

```zsh
#!/bin/zsh -p
```

</div>

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:

<div class="example">

```zsh
unsetopt privileged || exit
```

</div>

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.

<span id="index-RESTRICTED-1"></span> <span
id="index-NO_005fRESTRICTED"></span> <span
id="index-NORESTRICTED"></span> <span
id="index-restricted-shell-1"></span>

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 [Restricted
Shell](Invocation.html#Restricted-Shell).

<span id="index-SHIN_005fSTDIN"></span> <span
id="index-NO_005fSHIN_005fSTDIN"></span> <span
id="index-SHINSTDIN"></span> <span id="index-NOSHINSTDIN"></span>

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.

<span id="index-SINGLE_005fCOMMAND"></span> <span
id="index-NO_005fSINGLE_005fCOMMAND"></span> <span
id="index-SINGLECOMMAND"></span> <span
id="index-NOSINGLECOMMAND"></span> <span
id="index-single-command"></span> <span
id="index-INTERACTIVE_002c-use-of"></span>

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.

------------------------------------------------------------------------

<span id="Zle"></span>

### 16.2.12 Zle

<span id="index-BEEP"></span> <span id="index-NO_005fBEEP"></span> <span
id="index-NOBEEP"></span> <span id="index-beep_002c-enabling"></span>
<span id="index-enabling-the-beep"></span>

BEEP (+B) \<D>

Beep on error in ZLE.

<span id="index-COMBINING_005fCHARS"></span> <span
id="index-NO_005fCOMBINING_005fCHARS"></span> <span
id="index-COMBININGCHARS"></span> <span
id="index-NOCOMBININGCHARS"></span> <span
id="index-characters_002c-_0028Unicode_0029-combining"></span> <span
id="index-combining-characters-_0028Unicode_0029"></span> <span
id="index-Unicode-combining-characters"></span>

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.

<span id="index-EMACS"></span> <span id="index-NO_005fEMACS"></span>
<span id="index-NOEMACS"></span>

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.

<span id="index-OVERSTRIKE"></span> <span
id="index-NO_005fOVERSTRIKE"></span> <span
id="index-NOOVERSTRIKE"></span> <span
id="index-editor_002c-overstrike-mode"></span> <span
id="index-overstrike-mode_002c-of-editor"></span>

OVERSTRIKE

Start up the line editor in overstrike mode.

<span id="index-SINGLE_005fLINE_005fZLE"></span> <span
id="index-NO_005fSINGLE_005fLINE_005fZLE"></span> <span
id="index-SINGLELINEZLE"></span> <span
id="index-NOSINGLELINEZLE"></span> <span
id="index-editor_002c-single-line-mode"></span>

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.

<span id="index-VI"></span> <span id="index-NO_005fVI"></span> <span
id="index-NOVI"></span>

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.

<span id="index-ZLE"></span> <span id="index-NO_005fZLE"></span> <span
id="index-NOZLE"></span> <span id="index-editor_002c-enabling"></span>
<span id="index-enabling-the-editor"></span>

ZLE (-Z)

Use the zsh line editor. Set by default in interactive shells connected
to a terminal.

------------------------------------------------------------------------

<span id="Option-Aliases"></span> <span id="Option-Aliases-1"></span>

## 16.3 Option Aliases

<span id="index-options_002c-aliases"></span>

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.

<span id="index-BRACE_005fEXPAND"></span> <span
id="index-NO_005fBRACE_005fEXPAND"></span> <span
id="index-BRACEEXPAND"></span> <span id="index-NOBRACEEXPAND"></span>

BRACE_EXPAND

*NO\_*IGNORE_BRACES (ksh and bash compatibility)

<span id="index-DOT_005fGLOB"></span> <span
id="index-NO_005fDOT_005fGLOB"></span> <span id="index-DOTGLOB"></span>
<span id="index-NODOTGLOB"></span>

DOT_GLOB

GLOB_DOTS (bash compatibility)

<span id="index-HASH_005fALL"></span> <span
id="index-NO_005fHASH_005fALL"></span> <span id="index-HASHALL"></span>
<span id="index-NOHASHALL"></span>

HASH_ALL

HASH_CMDS (bash compatibility)

<span id="index-HIST_005fAPPEND"></span> <span
id="index-NO_005fHIST_005fAPPEND"></span> <span
id="index-HISTAPPEND"></span> <span id="index-NOHISTAPPEND"></span>

HIST_APPEND

APPEND_HISTORY (bash compatibility)

<span id="index-HIST_005fEXPAND"></span> <span
id="index-NO_005fHIST_005fEXPAND"></span> <span
id="index-HISTEXPAND"></span> <span id="index-NOHISTEXPAND"></span>

HIST_EXPAND

BANG_HIST (bash compatibility)

<span id="index-LOG"></span> <span id="index-NO_005fLOG"></span> <span
id="index-NOLOG"></span>

LOG

*NO\_*HIST_NO_FUNCTIONS (ksh compatibility)

<span id="index-MAIL_005fWARN"></span> <span
id="index-NO_005fMAIL_005fWARN"></span> <span
id="index-MAILWARN"></span> <span id="index-NOMAILWARN"></span>

MAIL_WARN

MAIL_WARNING (bash compatibility)

<span id="index-ONE_005fCMD"></span> <span
id="index-NO_005fONE_005fCMD"></span> <span id="index-ONECMD"></span>
<span id="index-NOONECMD"></span>

ONE_CMD

SINGLE_COMMAND (bash compatibility)

<span id="index-PHYSICAL"></span> <span
id="index-NO_005fPHYSICAL"></span> <span id="index-NOPHYSICAL"></span>

PHYSICAL

CHASE_LINKS (ksh and bash compatibility)

<span id="index-PROMPT_005fVARS"></span> <span
id="index-NO_005fPROMPT_005fVARS"></span> <span
id="index-PROMPTVARS"></span> <span id="index-NOPROMPTVARS"></span>

PROMPT_VARS

PROMPT_SUBST (bash compatibility)

<span id="index-STDIN"></span> <span id="index-NO_005fSTDIN"></span>
<span id="index-NOSTDIN"></span>

STDIN

SHIN_STDIN (ksh compatibility)

<span id="index-TRACK_005fALL"></span> <span
id="index-NO_005fTRACK_005fALL"></span> <span
id="index-TRACKALL"></span> <span id="index-NOTRACKALL"></span>

TRACK_ALL

HASH_CMDS (ksh compatibility)

------------------------------------------------------------------------

<span id="Single-Letter-Options"></span> <span
id="Single-Letter-Options-1"></span>

## 16.4 Single Letter Options

<span id="index-options_002c-single-letter"></span> <span
id="index-single-letter-options"></span>

------------------------------------------------------------------------

<span id="Default-set"></span>

### 16.4.1 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

------------------------------------------------------------------------

<span id="sh_002fksh-emulation-set"></span>

### 16.4.2 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

------------------------------------------------------------------------

<span id="Also-note"></span>

### 16.4.3 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

------------------------------------------------------------------------

This document was generated on *May 14, 2022* using [*texi2html
5.0*](http://www.nongnu.org/texi2html/).  
Zsh version 5.9, released on May 14, 2022.