zshoptions.1   [plain text]


.TH "ZSHOPTIONS" "1" "December 20, 2010" "zsh 4\&.3\&.11"
.SH "NAME"
zshoptions \- zsh options
.\" Yodl file: Zsh/options.yo
.SH "SPECIFYING OPTIONS"
Options are primarily referred to by name\&.
These names are case insensitive and underscores are ignored\&.
For example, `\fBallexport\fP\&' is equivalent to `\fBA__lleXP_ort\fP'\&.
.PP
The sense of an option name may be inverted by preceding it with
`\fBno\fP\&', so `\fBsetopt No_Beep\fP' is equivalent to `\fBunsetopt beep\fP'\&.
This inversion can only be done once, so `\fBnonobeep\fP\&' is \fInot\fP
a synonym for `\fBbeep\fP\&'\&.  Similarly, `\fBtify\fP' is not a synonym for
`\fBnonotify\fP\&' (the inversion of `\fBnotify\fP')\&.
.PP
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 \fBsh\fP/\fBksh\fP (used when the
\fBSH_OPTION_LETTERS\fP option is set)\&.
The single letter options can be used on the shell command line,
or with the \fBset\fP, \fBsetopt\fP and \fBunsetopt\fP
builtins, as normal Unix options preceded by `\fB\-\fP\&'\&.
.PP
The sense of the single letter options may be inverted by using
`\fB+\fP\&' instead of `\fB\-\fP'\&.
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, `\fB+n\fP\&' is the short name of `\fBexec\fP', and
`\fB\-n\fP\&' is the short name of its inversion, `\fBnoexec\fP'\&.
.PP
In strings of single letter options supplied to the shell at startup,
trailing whitespace will be ignored; for example the string `\fB\-f    \fP\&'
will be treated just as `\fB\-f\fP\&', but the string `\fB\-f i\fP' is an error\&.
This is because many systems which implement the `\fB#!\fP\&' mechanism for
calling scripts do not strip trailing whitespace\&.
.PP
.SH "DESCRIPTION OF OPTIONS"
In the following list, options set by default in all emulations are marked
<D>; those set by default only in csh, ksh, sh, or zsh emulations are marked
<C>, <K>, <S>, <Z> as appropriate\&.  When listing options (by `\fBsetopt\fP\&',
`\fBunsetopt\fP\&', `\fBset \-o\fP' or `\fBset +o\fP'), those turned on by default
appear in the list prefixed with `\fBno\fP\&'\&.  Hence (unless
\fBKSH_OPTION_PRINT\fP is set), `\fBsetopt\fP\&' shows all options whose settings
are changed from the default\&.
.PP
.SS "Changing Directories"
.PD 0
.TP
.PD
\fBAUTO_CD\fP (\fB\-J\fP)
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 \fBcd\fP
command to that directory\&.
.TP
\fBAUTO_PUSHD\fP (\fB\-N\fP)
Make \fBcd\fP push the old directory onto the directory stack\&.
.TP
\fBCDABLE_VARS\fP (\fB\-T\fP)
If the argument to a \fBcd\fP command (or an implied \fBcd\fP with the
\fBAUTO_CD\fP 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 `\fB~\fP\&' (see
the section `Filename Expansion\&')\&.
.TP
\fBCHASE_DOTS\fP
When changing to a directory containing a path segment `\fB\&.\&.\fP\&' which would
otherwise be treated as canceling the previous segment in the path (in
other words, `\fBfoo/\&.\&.\fP\&' would be removed from the path, or if `\fB\&.\&.\fP' 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 \fBCHASE_LINKS\fP\&.
.RS
.PP
For example, suppose \fB/foo/bar\fP is a link to the directory \fB/alt/rod\fP\&.
Without this option set, `\fBcd /foo/bar/\&.\&.\fP\&' changes to \fB/foo\fP; with it
set, it changes to \fB/alt\fP\&.  The same applies if the current directory
is \fB/foo/bar\fP and `\fBcd \&.\&.\fP\&' is used\&.  Note that all other symbolic
links in the path will also be resolved\&.
.RE
.TP
\fBCHASE_LINKS\fP (\fB\-w\fP)
Resolve symbolic links to their true values when changing directory\&.
This also has the effect of \fBCHASE_DOTS\fP, i\&.e\&. a `\fB\&.\&.\fP\&' path segment
will be treated as referring to the physical parent, even if the preceding
path segment is a symbolic link\&.
.TP
\fBPOSIX_CD\fP
Modifies the behaviour of \fBcd\fP, \fBchdir\fP and \fBpushd\fP commands
to make them more compatible with the POSIX standard\&. The behaviour with
the option unset is described in the documentation for the \fBcd\fP
builtin in
\fIzshbuiltins\fP(1)\&.
If the option is set, the shell does not test for directories beneath
the local directory (`\fB\&.\fP\&') until after all directories in \fBcdpath\fP
have been tested\&.
.RS
.PP
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 \fBpushd\fP is still limited to interactive
shells); and any use of a component of \fBCDPATH\fP, including a `\fB\&.\fP\&' but
excluding an empty component that is otherwise treated as `\fB\&.\fP\&', causes
the directory to be printed\&.
.RE
.TP
\fBPUSHD_IGNORE_DUPS\fP
Don\&'t push multiple copies of the same directory onto the directory stack\&.
.TP
\fBPUSHD_MINUS\fP
Exchanges the meanings of `\fB+\fP\&' and `\fB\-\fP'
when used with a number to specify a directory in the stack\&.
.TP
\fBPUSHD_SILENT\fP (\fB\-E\fP)
Do not print the directory stack after \fBpushd\fP or \fBpopd\fP\&.
.TP
\fBPUSHD_TO_HOME\fP (\fB\-D\fP)
Have \fBpushd\fP with no arguments act like `\fBpushd $HOME\fP\&'\&.
.PP
.SS "Completion"
.PD 0
.TP
.PD
\fBALWAYS_LAST_PROMPT\fP <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 \fIno\fP numeric argument\&.
.TP
\fBALWAYS_TO_END\fP
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\&.
.TP
\fBAUTO_LIST\fP (\fB\-9\fP) <D>
Automatically list choices on an ambiguous completion\&.
.TP
\fBAUTO_MENU\fP <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 \fBMENU_COMPLETE\fP\&.
.TP
\fBAUTO_NAME_DIRS\fP
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 `\fB%~\fP\&'
and related prompt sequences, and will be available when completion
is performed on a word starting with `\fB~\fP\&'\&.
(Otherwise, the parameter must be used in the form `\fB~\fP\fIparam\fP\&' first\&.)
.TP
\fBAUTO_PARAM_KEYS\fP <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 `\fB}\fP\&', `\fB:\fP',
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 `\fB,\fP\&', which will be removed if `\fB}\fP' is typed next\&.
.TP
\fBAUTO_PARAM_SLASH\fP <D>
If a parameter is completed whose content is the name of a directory,
then add a trailing slash instead of a space\&.
.TP
\fBAUTO_REMOVE_SLASH\fP <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\&.
.TP
\fBBASH_AUTO_LIST\fP
On an ambiguous completion, automatically list choices when the
completion function is called twice in succession\&.  This takes
precedence over \fBAUTO_LIST\fP\&.  The setting of \fBLIST_AMBIGUOUS\fP is
respected\&.  If \fBAUTO_MENU\fP is set, the menu behaviour will then start
with the third press\&.  Note that this will not work with
\fBMENU_COMPLETE\fP, since repeated completion calls immediately cycle
through the list in that case\&.
.TP
\fBCOMPLETE_ALIASES\fP
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\&.
.TP
\fBCOMPLETE_IN_WORD\fP
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\&.
.TP
\fBGLOB_COMPLETE\fP
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 \fBMENU_COMPLETE\fP\&. The matches are generated as if
a `\fB*\fP\&' was added to the end of the word, or inserted at the cursor when
\fBCOMPLETE_IN_WORD\fP 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\&.
.RS
.PP
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 \fBGLOB_COMPLETE\fP option does not have this effect\&.
.RE
.TP
\fBHASH_LIST_ALL\fP <D>
Whenever a command completion is attempted, make sure the entire
command path is hashed first\&.  This makes the first completion slower\&.
.TP
\fBLIST_AMBIGUOUS\fP <D>
This option works when \fBAUTO_LIST\fP or \fBBASH_AUTO_LIST\fP 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 \fBBASH_AUTO_LIST\fP, this means that the list
will be delayed to the third call of the function\&.
.TP
\fBLIST_BEEP\fP <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 \fBBEEP\fP is also set; this may
be modified if completion is called from a user\-defined widget\&.
.TP
\fBLIST_PACKED\fP
Try to make the completion list smaller (occupying less lines) by
printing the matches in columns with different widths\&.
.TP
\fBLIST_ROWS_FIRST\fP
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\&.
.TP
\fBLIST_TYPES\fP (\fB\-X\fP) <D>
When listing files that are possible completions, show the
type of each file with a trailing identifying mark\&.
.TP
\fBMENU_COMPLETE\fP (\fB\-Y\fP)
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\&.
\fBreverse\-menu\-complete\fP may be used to loop through the list
in the other direction\&. This option overrides \fBAUTO_MENU\fP\&.
.TP
\fBREC_EXACT\fP (\fB\-S\fP)
In completion, recognize exact matches even
if they are ambiguous\&.
.PP
.SS "Expansion and Globbing"
.PD 0
.TP
.PD
\fBBAD_PATTERN\fP (\fB+2\fP) <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\&.)
.TP
\fBBARE_GLOB_QUAL\fP <Z>
In a glob pattern, treat a trailing set of parentheses as a qualifier
list, if it contains no `\fB|\fP\&', `\fB(\fP' or (if special) `\fB~\fP'
characters\&.  See the section `Filename Generation\&'\&.
.TP
\fBBRACE_CCL\fP
Expand expressions in braces which would not otherwise undergo brace
expansion to a lexically ordered list of all the characters\&.  See
the section `Brace Expansion\&'\&.
.TP
\fBCASE_GLOB\fP <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, \fBcvs(/)\fP
can match the directory \fBCVS\fP owing to the presence of the globbing flag
(unless the option \fBBARE_GLOB_QUAL\fP is unset)\&.
.TP
\fBCASE_MATCH\fP <D>
Make regular expressions using the \fBzsh/regex\fP module (including
matches with \fB=~\fP) sensitive to case\&.
.TP
\fBCSH_NULL_GLOB\fP <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 \fBNOMATCH\fP\&.
.TP
\fBEQUALS\fP <Z>
Perform \fB=\fP filename expansion\&.
(See the section `Filename Expansion\&'\&.)
.TP
\fBEXTENDED_GLOB\fP
Treat the `\fB#\fP\&', `\fB~\fP' and `\fB^\fP' characters as part of patterns
for filename generation, etc\&.  (An initial unquoted `\fB~\fP\&'
always produces named directory expansion\&.)
.TP
\fBGLOB\fP (\fB+F\fP, ksh: \fB+f\fP) <D>
Perform filename generation (globbing)\&.
(See the section `Filename Generation\&'\&.)
.TP
\fBGLOB_ASSIGN\fP <C>
If this option is set, filename generation (globbing) is
performed on the right hand side of scalar parameter assignments of
the form `\fIname\fP\fB=\fP\fIpattern\fP (e\&.g\&. `\fBfoo=*\fP\&')\&.
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 `\fIname\fP\fB=(\fP\fIvalue\fP\fB)\fP\&'
(e\&.g\&. `\fBfoo=(*)\fP\&') 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\&.
.TP
\fBGLOB_DOTS\fP (\fB\-4\fP)
Do not require a leading `\fB\&.\fP\&' in a filename to be matched explicitly\&.
.TP
\fBGLOB_SUBST\fP <C> <K> <S>
Treat any characters resulting from parameter expansion as being
eligible for file 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\&.
.TP
\fBHIST_SUBST_PATTERN\fP
Substitutions using the \fB:s\fP and \fB:&\fP history modifiers are performed
with pattern matching instead of string matching\&.  This occurs wherever
history modifiers are valid, including glob qualifiers and parameters\&.
See
the section Modifiers in \fIzshexpn\fP(1)\&.
.TP
\fBIGNORE_BRACES\fP (\fB\-I\fP) <S>
Do not perform brace expansion\&.
.TP
\fBKSH_GLOB\fP <K>
In pattern matching, the interpretation of parentheses is affected by
a preceding `\fB@\fP\&', `\fB*\fP', `\fB+\fP', `\fB?\fP' or `\fB!\fP'\&.
See the section `Filename Generation\&'\&.
.TP
\fBMAGIC_EQUAL_SUBST\fP
All unquoted arguments of the form `\fIanything\fP\fB=\fP\fIexpression\fP\&'
appearing after the command name have filename expansion (that is,
where \fIexpression\fP has a leading `\fB~\fP\&' or `\fB=\fP') performed on
\fIexpression\fP 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
\fBecho foo=~/bar:~/rod\fP, both occurrences of \fB~\fP would be replaced\&.
Note that this happens anyway with \fBtypeset\fP and similar statements\&.
.RS
.PP
This option respects the setting of the \fBKSH_TYPESET\fP option\&.  In other
words, if both options are in effect, arguments looking like
assignments will not undergo word splitting\&.
.RE
.TP
\fBMARK_DIRS\fP (\fB\-8\fP, ksh: \fB\-X\fP)
Append a trailing `\fB/\fP\&' to all directory
names resulting from filename generation (globbing)\&.
.TP
\fBMULTIBYTE\fP <C> <K> <Z>
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\&.
.RS
.PP
The option is on by default if the shell was compiled with
\fBMULTIBYTE_SUPPORT\fP except in \fBsh\fP emulation; otherwise it is off by
default and has no effect if turned on\&.  The mode is off in \fBsh\fP
emulation for compatibility but for interactive use may need to be
turned on if the terminal interprets multibyte characters\&.
.PP
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\&.
.PP
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\&.
.RE
.TP
\fBNOMATCH\fP (\fB+3\fP) <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 `\fB~\fP\&' or `\fB=\fP'\&.
.TP
\fBNULL_GLOB\fP (\fB\-G\fP)
If a pattern for filename generation has no matches,
delete the pattern from the argument list instead
of reporting an error\&.  Overrides \fBNOMATCH\fP\&.
.TP
\fBNUMERIC_GLOB_SORT\fP
If numeric filenames are matched by a filename generation pattern,
sort the filenames numerically rather than lexicographically\&.
.TP
\fBRC_EXPAND_PARAM\fP (\fB\-P\fP)
Array expansions of the form
`\fIfoo\fP\fB${\fP\fIxx\fP\fB}\fP\fIbar\fP\&', where the parameter
\fIxx\fP is set to \fB(\fP\fIa b c\fP\fB)\fP, are substituted with
`\fIfooabar foobbar foocbar\fP\&' instead of the default
`\fIfooa b cbar\fP\&'\&.  Note that an empty array will therefore cause
all arguments to be removed\&.
.TP
\fBREMATCH_PCRE\fP <Z>
If set, regular expression matching with the \fB=~\fP operator will use
Perl\-Compatible Regular Expressions from the PCRE library, if available\&.
If not set, regular expressions will use the extended regexp syntax
provided by the system libraries\&.
.TP
\fBSH_GLOB\fP <K> <S>
Disables the special meaning of `\fB(\fP\&', `\fB|\fP', `\fB)\fP'
and \&'\fB<\fP' for globbing the result of parameter and command substitutions,
and in some other places where
the shell accepts patterns\&.  This option is set by default if zsh is
invoked as \fBsh\fP or \fBksh\fP\&.
.TP
\fBUNSET\fP (\fB+u\fP, ksh: \fB+u\fP) <K> <S> <Z>
Treat unset parameters as if they were empty when substituting\&.
Otherwise they are treated as an error\&.
.TP
\fBWARN_CREATE_GLOBAL\fP
Print a warning message when a global parameter is created in a function
by an assignment\&.  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 \fBtypeset \-g\fP 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\&.
.PP
.SS "History"
.PD 0
.TP
.PD
\fBAPPEND_HISTORY\fP <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
\fB$SAVEHIST\fP (see also the HIST_SAVE_BY_COPY option)\&.
.TP
\fBBANG_HIST\fP (\fB+K\fP) <C> <Z>
Perform textual history expansion, \fBcsh\fP\-style,
treating the character `\fB!\fP\&' specially\&.
.TP
\fBEXTENDED_HISTORY\fP <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:
.RS
.PP
`\fB:\fP \fI<beginning time>\fP\fB:\fP\fI<elapsed seconds>\fP\fB;\fP\fI<command>\fP\&'\&.
.RE
.TP
\fBHIST_ALLOW_CLOBBER\fP
Add `\fB|\fP\&' to output redirections in the history\&.  This allows history
references to clobber files even when \fBCLOBBER\fP is unset\&.
.TP
\fBHIST_BEEP\fP <D>
Beep when an attempt is made to access a history entry which
isn\&'t there\&.
.TP
\fBHIST_EXPIRE_DUPS_FIRST\fP
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 \fBHISTSIZE\fP to a larger number
than \fBSAVEHIST\fP in order to give you some room for the duplicated
events, otherwise this option will behave just like
\fBHIST_IGNORE_ALL_DUPS\fP once the history fills up with unique events\&.
.TP
\fBHIST_FCNTL_LOCK\fP
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 \fBfcntl\fP 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\&.
.TP
\fBHIST_FIND_NO_DUPS\fP
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\&.
.TP
\fBHIST_IGNORE_ALL_DUPS\fP
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)\&.
.TP
\fBHIST_IGNORE_DUPS\fP (\fB\-h\fP)
Do not enter command lines into the history list
if they are duplicates of the previous event\&.
.TP
\fBHIST_IGNORE_SPACE\fP (\fB\-g\fP)
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\&.
.TP
\fBHIST_LEX_WORDS\fP
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\&.
.TP
\fBHIST_NO_FUNCTIONS\fP
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\&.
.TP
\fBHIST_NO_STORE\fP
Remove the \fBhistory\fP (\fBfc \-l\fP) 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\&.
.TP
\fBHIST_REDUCE_BLANKS\fP
Remove superfluous blanks from each command line
being added to the history list\&.
.TP
\fBHIST_SAVE_BY_COPY\fP <D>
When the history file is re\-written, we normally write out a copy of
the file named $HISTFILE\&.new and then rename it over the old one\&.
However, if this option is unset, we instead truncate the old
history file and write out the new version in\-place\&.  If one of the
history\-appending options is enabled, this option only has an effect
when the enlarged history file needs to be re\-written to trim it
down to size\&.  Disable this only if you have special needs, as doing
so makes it possible to lose history entries if zsh gets interrupted
during the save\&.
.RS
.PP
When writing out a copy of the history file, zsh preserves the old
file\&'s permissions and group information, but will refuse to write
out a new file if it would change the history file\&'s owner\&.
.RE
.TP
\fBHIST_SAVE_NO_DUPS\fP
When writing out the history file, older commands that duplicate
newer ones are omitted\&.
.TP
\fBHIST_VERIFY\fP
Whenever the user enters a line with history expansion,
don\&'t execute the line directly; instead, perform
history expansion and reload the line into the editing buffer\&.
.TP
\fBINC_APPEND_HISTORY\fP
This options works like \fBAPPEND_HISTORY\fP except that new history lines
are added to the \fB$HISTFILE\fP 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
\fB$SAVEHIST\fP (see also the HIST_SAVE_BY_COPY option)\&.
.TP
\fBSHARE_HISTORY\fP <K>
.RS
.PP
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 \fBINC_APPEND_HISTORY\fP)\&.
The history lines are also output with timestamps ala
\fBEXTENDED_HISTORY\fP (which makes it easier to find the spot where
we left off reading the file after it gets re\-written)\&.
.PP
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\&.
.PP
If you find that you want more control over when commands
get imported, you may wish to turn \fBSHARE_HISTORY\fP off,
\fBINC_APPEND_HISTORY\fP on, and then manually import
commands whenever you need them using `\fBfc \-RI\fP\&'\&.
.RE
.RE
.PP
.SS "Initialisation"
.PD 0
.TP
.PD
\fBALL_EXPORT\fP (\fB\-a\fP, ksh: \fB\-a\fP)
All parameters subsequently defined are automatically exported\&.
.TP
\fBGLOBAL_EXPORT\fP (\fB<Z>\fP)
If this option is set, passing the \fB\-x\fP flag to the builtins \fBdeclare\fP,
\fBfloat\fP, \fBinteger\fP, \fBreadonly\fP and \fBtypeset\fP (but not \fBlocal\fP)
will also set the \fB\-g\fP flag;  hence parameters exported to
the environment will not be made local to the enclosing function, unless
they were already or the flag \fB+g\fP is given explicitly\&.  If the option is
unset, exported parameters will be made local in just the same way as any
other parameter\&.
.RS
.PP
This option is set by default for backward compatibility; it is not
recommended that its behaviour be relied upon\&.  Note that the builtin
\fBexport\fP always sets both the \fB\-x\fP and \fB\-g\fP flags, and hence its
effect extends beyond the scope of the enclosing function; this is the
most portable way to achieve this behaviour\&.
.RE
.TP
\fBGLOBAL_RCS\fP (\fB\-d\fP) <D>
If this option is unset, the startup files \fB/etc/zprofile\fP,
\fB/etc/zshrc\fP, \fB/etc/zlogin\fP and \fB/etc/zlogout\fP will not be run\&.  It
can be disabled and re\-enabled at any time, including inside local startup
files (\fB\&.zshrc\fP, etc\&.)\&.
.TP
\fBRCS\fP (\fB+f\fP) <D>
After \fB/etc/zshenv\fP is sourced on startup, source the
\fB\&.zshenv\fP, \fB/etc/zprofile\fP, \fB\&.zprofile\fP,
\fB/etc/zshrc\fP, \fB\&.zshrc\fP, \fB/etc/zlogin\fP, \fB\&.zlogin\fP, and \fB\&.zlogout\fP
files, as described in the section `Files\&'\&.
If this option is unset, the \fB/etc/zshenv\fP 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\&.
.PP
.SS "Input/Output"
.PD 0
.TP
.PD
\fBALIASES\fP <D>
Expand aliases\&.
.TP
\fBCLOBBER\fP (\fB+C\fP, ksh: \fB+C\fP) <D>
Allows `\fB>\fP\&' redirection to truncate existing files,
and `\fB>>\fP\&' to create files\&.
Otherwise `\fB>!\fP\&' or `\fB>|\fP' must be used to truncate a file,
and `\fB>>!\fP\&' or `\fB>>|\fP' to create a file\&.
.TP
\fBCORRECT\fP (\fB\-0\fP)
Try to correct the spelling of commands\&.
Note that, when the \fBHASH_LIST_ALL\fP 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\&.
.RS
.PP
The shell variable \fBCORRECT_IGNORE\fP may be set to a pattern to
match words that will never be offered as corrections\&.
.RE
.TP
\fBCORRECT_ALL\fP (\fB\-O\fP)
Try to correct the spelling of all arguments in a line\&.
.TP
\fBDVORAK\fP
Use the Dvorak keyboard instead of the standard qwerty keyboard as a basis
for examining spelling mistakes for the \fBCORRECT\fP and \fBCORRECT_ALL\fP
options and the \fBspell\-word\fP editor command\&.
.TP
\fBFLOW_CONTROL\fP <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\&.
.TP
\fBIGNORE_EOF\fP (\fB\-7\fP)
Do not exit on end\-of\-file\&.  Require the use
of \fBexit\fP or \fBlogout\fP instead\&.
However, ten consecutive EOFs will cause the shell to exit anyway,
to avoid the shell hanging if its tty goes away\&.
.RS
.PP
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\&.
.RE
.TP
\fBINTERACTIVE_COMMENTS\fP (\fB\-k\fP) <K> <S>
Allow comments even in interactive shells\&.
.TP
\fBHASH_CMDS\fP <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 \fBCORRECT\fP is set, commands whose names do not appear in
the functions or aliases hash tables are hashed in order to avoid
reporting them as spelling errors\&.
.TP
\fBHASH_DIRS\fP <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 \fBHASH_CMDS\fP nor \fBCORRECT\fP is set\&.
.TP
\fBMAIL_WARNING\fP (\fB\-U\fP)
Print a warning message if a mail file has been
accessed since the shell last checked\&.
.TP
\fBPATH_DIRS\fP (\fB\-Q\fP)
Perform a path search even on command names with slashes in them\&.
Thus if `\fB/usr/local/bin\fP\&' is in the user's path, and he or she types
`\fBX11/xinit\fP\&', the command `\fB/usr/local/bin/X11/xinit\fP' will be executed
(assuming it exists)\&.
Commands explicitly beginning with `\fB/\fP\&', `\fB\&./\fP' or `\fB\&.\&./\fP'
are not subject to the path search\&.
This also applies to the `\fB\&.\fP\&' builtin\&.
.RS
.PP
Note that subdirectories of the current directory are always searched for
executables specified in this form\&.  This takes place before any search
indicated by this option, and regardless of whether `\fB\&.\fP\&' or the current
directory appear in the command search path\&.
.RE
.TP
\fBPATH_SCRIPT\fP <K> <S>
If this option is not set, a script passed as the first non\-option argument
to the shell must contain the name of the file to open\&.  If this
option is set, and the script does not specify a directory path,
the script is looked for first in the current directory, then in the
command path\&.  See
the section INVOCATION in \fIzsh\fP(1)\&.
.TP
\fBPRINT_EIGHT_BIT\fP
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 \fIctype\fP(3))\&.
.TP
\fBPRINT_EXIT_VALUE\fP (\fB\-1\fP)
Print the exit value of programs with non\-zero exit status\&.
.TP
\fBRC_QUOTES\fP
Allow the character sequence `\fB\&''\fP' to signify a single quote
within singly quoted strings\&.  Note this does not apply in quoted strings
using the format \fB$\&'\fP\fI\&.\&.\&.\fP\fB'\fP, where a backslashed single quote can
be used\&.
.TP
\fBRM_STAR_SILENT\fP (\fB\-H\fP) <K> <S>
Do not query the user before executing `\fBrm *\fP\&' or `\fBrm path/*\fP'\&.
.TP
\fBRM_STAR_WAIT\fP
If querying the user before executing `\fBrm *\fP\&' or `\fBrm path/*\fP',
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 `\fB*\fP\&' in ZLE (with tab)\&.
.TP
\fBSHORT_LOOPS\fP <C> <Z>
Allow the short forms of \fBfor\fP, \fBrepeat\fP, \fBselect\fP,
\fBif\fP, and \fBfunction\fP constructs\&.
.TP
\fBSUN_KEYBOARD_HACK\fP (\fB\-L\fP)
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 \fBKEYBOARD_HACK\fP lets you choose the
character to be removed\&.
.PP
.SS "Job Control"
.PD 0
.TP
.PD
\fBAUTO_CONTINUE\fP
With this option set, stopped jobs that are removed from the job table
with the \fBdisown\fP builtin command are automatically sent a \fBCONT\fP
signal to make them running\&.
.TP
\fBAUTO_RESUME\fP (\fB\-W\fP)
Treat single word simple commands without redirection
as candidates for resumption of an existing job\&.
.TP
\fBBG_NICE\fP (\fB\-6\fP) <C> <Z>
Run all background jobs at a lower priority\&.  This option
is set by default\&.
.TP
\fBCHECK_JOBS\fP <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\&.
\fBNO_CHECK_JOBS\fP is best used only in combination with \fBNO_HUP\fP, else
such jobs will be killed automatically\&.
.RS
.PP
The check is omitted if the commands run from the previous command line
included a `\fBjobs\fP\&' command, since it is assumed the user is aware that
there are background or suspended jobs\&.  A `\fBjobs\fP\&' command run from one
of the hook functions defined in
the section SPECIAL FUNCTIONS in \fIzshmisc\fP(1)
is not counted for this purpose\&.
.RE
.TP
\fBHUP\fP <Z>
Send the \fBHUP\fP signal to running jobs when the
shell exits\&.
.TP
\fBLONG_LIST_JOBS\fP (\fB\-R\fP)
List jobs in the long format by default\&.
.TP
\fBMONITOR\fP (\fB\-m\fP, ksh: \fB\-m\fP)
Allow job control\&.  Set by default in interactive shells\&.
.TP
\fBNOTIFY\fP (\fB\-5\fP, ksh: \fB\-b\fP) <Z>
Report the status of background jobs immediately, rather than
waiting until just before printing a prompt\&.
.TP
\fBPOSIX_JOBS\fP <K> <S>
This option makes job control more compliant with the POSIX standard\&.
.RS
.PP
When the option is not set, the \fBMONITOR\fP option is unset on entry to
subshells, so that job control is no longer active\&.  When the option is
set, the \fBMONITOR\fP option and job control remain active in the
subshell, but note that the subshell has no access to jobs in the parent
shell\&.
.PP
When the option is not set, jobs put in the background or foreground
with \fBbg\fP or \fBfg\fP are displayed with the same information that would
be reported by \fBjobs\fP\&.  When the option is set, only the text is
printed\&.  The output from \fBjobs\fP itself is not affected by the option\&.
.PP
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 \fBjobs\fP is empty
until a job is started within the subshell\&.
.PP
When the option is set, it becomes possible to use the \fBwait\fP builtin to
wait for the last job started in the background (as given by \fB$!\fP) even
if that job has already exited\&.  This works even if the option is turned
on temporarily around the use of the \fBwait\fP builtin\&.
.RE
.RE
.PP
.SS "Prompting"
.PD 0
.TP
.PD
\fBPROMPT_BANG\fP <K>
If set, `\fB!\fP\&' is treated specially in prompt expansion\&.
See
EXPANSION OF PROMPT SEQUENCES in \fIzshmisc\fP(1)\&.
.TP
\fBPROMPT_CR\fP (\fB+V\fP) <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\&.
.TP
\fBPROMPT_SP\fP <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 \fBPROMPT_CR\fP 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)\&.
.RS
.PP
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 \fBPROMPT_EOL_MARK\fP can be
used to customize how the end of partial lines are shown\&.
.PP
NOTE: if the \fBPROMPT_CR\fP option is not set, enabling this option will
have no effect\&.  This option is on by default\&.
.RE
.TP
\fBPROMPT_PERCENT\fP <C> <Z>
If set, `\fB%\fP\&' is treated specially in prompt expansion\&.
See
EXPANSION OF PROMPT SEQUENCES in \fIzshmisc\fP(1)\&.
.TP
\fBPROMPT_SUBST\fP <K> <S>
If set, \fIparameter expansion\fP, \fIcommand substitution\fP and
\fIarithmetic expansion\fP are performed in prompts\&.  Substitutions
within prompts do not affect the command status\&.
.TP
\fBTRANSIENT_RPROMPT\fP
Remove any right prompt from display when accepting a command
line\&.  This may be useful with terminals with other cut/paste methods\&.
.PP
.SS "Scripts and Functions"
.PD 0
.TP
.PD
\fBC_BASES\fP
Output hexadecimal numbers in the standard C format, for example `\fB0xFF\fP\&'
instead of the usual `\fB16#FF\fP\&'\&.  If the option \fBOCTAL_ZEROES\fP is also
set (it is not by default), octal numbers will be treated similarly and
hence appear as `\fB077\fP\&' instead of `\fB8#77\fP'\&.  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 \fBC_BASES\fP\&.
.TP
\fBC_PRECEDENCES\fP
This alters the precedence of arithmetic operators to be more
like C and other programming languages;
the section ARITHMETIC EVALUATION in \fIzshmisc\fP(1)
has an explicit list\&.
.TP
\fBDEBUG_BEFORE_CMD\fP
Run the \fBDEBUG\fP 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\&.
.TP
\fBERR_EXIT\fP (\fB\-e\fP, ksh: \fB\-e\fP)
If a command has a non\-zero exit status, execute the \fBZERR\fP
trap, if set, and exit\&.  This is disabled while running initialization
scripts\&.
.RS
.PP
The behaviour is also disabled inside \fBDEBUG\fP traps\&.  In this
case the option is handled specially: it is unset on entry to
the trap\&.  If the option \fBDEBUG_BEFORE_CMD\fP is set,
as it is by default, and the option \fBERR_EXIT\fP is found to have been set
on exit, then the command for which the \fBDEBUG\fP trap is being executed is
skipped\&.  The option is restored after the trap exits\&.
.RE
.TP
\fBERR_RETURN\fP
If a command has a non\-zero exit status, return immediately from the
enclosing function\&.  The logic is identical to that for \fBERR_EXIT\fP,
except that an implicit \fBreturn\fP statement is executed instead of an
\fBexit\fP\&.  This will trigger an exit at the outermost level of a
non\-interactive script\&.
.TP
\fBEVAL_LINENO\fP <Z>
If set, line numbers of expressions evaluated using the builtin \fBeval\fP
are tracked separately of the enclosing environment\&.  This applies both
to the parameter \fBLINENO\fP and the line number output by the prompt
escape \fB%i\fP\&.  If the option is set, the prompt escape \fB%N\fP will output
the string `\fB(eval)\fP\&' instead of the script or function name as an
indication\&.   (The two prompt escapes are typically used in the parameter
\fBPS4\fP to be output when the option \fBXTRACE\fP is set\&.)  If
\fBEVAL_LINENO\fP is unset, the line number of the surrounding script or
function is retained during the evaluation\&.
.TP
\fBEXEC\fP (\fB+n\fP, ksh: \fB+n\fP) <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 `\fB\-n\fP\&' is supplied to the shell at startup\&.
.TP
\fBFUNCTION_ARGZERO\fP <C> <Z>
When executing a shell function or sourcing a script, set \fB$0\fP
temporarily to the name of the function/script\&.
.TP
\fBLOCAL_OPTIONS\fP <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
\fBPRIVILEGED\fP and \fBRESTRICTED\fP\&.  Otherwise, only this option and the
\fBXTRACE\fP and \fBPRINT_EXIT_VALUE\fP 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 `\fBemulate \-L zsh\fP\&'; the \fB\-L\fP activates
\fBLOCAL_OPTIONS\fP\&.
.TP
\fBLOCAL_TRAPS\fP <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 \fIprior\fP to altering the
trap behaviour in a function; unlike \fBLOCAL_OPTIONS\fP, 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,
.RS
.PP
.RS
.nf
\fBunsetopt localtraps
trap \- INT
fn() { setopt localtraps; trap \&'' INT; sleep 3; }\fP
.fi
.RE
.PP
will restore normal handling of \fBSIGINT\fP after the function exits\&.
.RE
.TP
\fBMULTI_FUNC_DEF\fP <Z>
Allow definitions of multiple functions at once in the form `\fBfn1
fn2\fP\fI\&.\&.\&.\fP\fB()\fP\&'; if the option is not set, this causes
a parse error\&.  Definition of multiple functions with the \fBfunction\fP
keyword is always allowed\&.  Multiple function definitions are not often
used and can cause obscure errors\&.
.TP
\fBMULTIOS\fP <Z>
Perform implicit \fBtee\fPs or \fBcat\fPs when multiple
redirections are attempted (see the section `Redirection\&')\&.
.TP
\fBOCTAL_ZEROES\fP <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\&.
.RS
.PP
Sequences of digits indicating a numeric base such as the `\fB08\fP\&'
component in `\fB08#77\fP\&' are always interpreted as decimal, regardless
of leading zeroes\&.
.RE
.TP
\fBSOURCE_TRACE\fP
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 \fBXTRACE\fP option, with the message \fB<sourcetrace>\fP\&.
A file may be loaded by the shell itself when it
starts up and shuts down (\fBStartup/Shutdown Files\fP) or by the use of
the `\fBsource\fP\&' and `\fBdot\fP' builtin commands\&.
.TP
\fBTYPESET_SILENT\fP
If this is unset, executing any of the `\fBtypeset\fP\&' 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 `\fB\-m\fP\&' option\&.  The option `\fB\-p\fP' is available whether or not
the option is set\&.
.TP
\fBVERBOSE\fP (\fB\-v\fP, ksh: \fB\-v\fP)
Print shell input lines as they are read\&.
.TP
\fBXTRACE\fP (\fB\-x\fP, ksh: \fB\-x\fP)
Print commands and their arguments as they are executed\&.  The
output is proceded by the value of \fB$PS4\fP, formatted as described
in
the section EXPANSION OF PROMPT SEQUENCES in \fIzshmisc\fP(1)\&.
.PP
.SS "Shell Emulation"
.PD 0
.TP
.PD
\fBBASH_REMATCH\fP
When set, matches performed with the \fB=~\fP operator will set the
\fBBASH_REMATCH\fP array variable, instead of the default \fBMATCH\fP and
\fBmatch\fP variables\&.  The first element of the \fBBASH_REMATCH\fP array
will contain the entire matched text and subsequent elements will contain
extracted substrings\&.  This option makes more sense when \fBKSH_ARRAYS\fP 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 \fBMATCH\fP variable
contains the entire matched text and the \fBmatch\fP array variable contains
substrings\&.
.TP
\fBBSD_ECHO\fP <S>
Make the \fBecho\fP builtin compatible with the BSD \fIecho\fP(1) command\&.
This disables backslashed escape sequences in echo strings unless the
\fB\-e\fP option is specified\&.
.TP
\fBCSH_JUNKIE_HISTORY\fP <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, defaulting to the
previous command\&.
.TP
\fBCSH_JUNKIE_LOOPS\fP <C>
Allow loop bodies to take the form `\fIlist\fP; \fBend\fP\&' instead of
`\fBdo\fP \fIlist\fP; \fBdone\fP\&'\&.
.TP
\fBCSH_JUNKIE_QUOTES\fP <C>
Changes the rules for single\- and double\-quoted text to match that of
\fBcsh\fP\&.  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 `\fB$\fP\&', `\fB`\fP'
or `\fB"\fP\&' (and `\fB\e\fP' itself no longer needs escaping)\&.
Command substitutions are only expanded once, and cannot be nested\&.
.TP
\fBCSH_NULLCMD\fP <C>
Do not use the values of \fBNULLCMD\fP and \fBREADNULLCMD\fP 
when running redirections with no command\&.  This make 
such redirections fail (see the section `Redirection\&')\&.
.TP
\fBKSH_ARRAYS\fP <K> <S>
Emulate \fBksh\fP array handling as closely as possible\&.  If this option
is set, array elements are numbered from zero, an array parameter
without subscript refers to the first element instead of the whole array,
and braces are required to delimit a subscript (`\fB${path[2]}\fP\&' rather
than just `\fB$path[2]\fP\&')\&.
.TP
\fBKSH_AUTOLOAD\fP <K> <S>
Emulate \fBksh\fP 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 \fBksh\fP\-style case \- of the file
containing only a simple definition of the function \- is always handled
in the \fBksh\fP\-compatible manner\&.)
.TP
\fBKSH_OPTION_PRINT\fP <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\&.
.TP
\fBKSH_TYPESET\fP <K>
Alters the way arguments to the \fBtypeset\fP family of commands, including
\fBdeclare\fP, \fBexport\fP, \fBfloat\fP, \fBinteger\fP, \fBlocal\fP and
\fBreadonly\fP, 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\&.
.TP
\fBKSH_ZERO_SUBSCRIPT\fP
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 \fBKSH_ARRAYS\fP is also set\&.
.RS
.PP
If neither this option nor \fBKSH_ARRAYS\fP 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 \fBKSH_ZERO_SUBSCRIPT\fP is not
set,
.PP
.RS
.nf
\fBarray[0]=(element)\fP
.fi
.RE
.PP
is an error, while
.PP
.RS
.nf
\fBarray[0,1]=(element)\fP
.fi
.RE
.PP
is not and will replace the first element of the array\&.
.PP
This option is for compatibility with older versions of the shell and
is not recommended in new code\&.
.RE
.TP
\fBPOSIX_ALIASES\fP <K> <S>
When this option is set, reserved words are not candidates for
alias expansion:  it is still possible to declare any of them as an alias,
but the alias will never be expanded\&.  Reserved words are described in
the section RESERVED WORDS in \fIzshmisc\fP(1)\&.
.RS
.PP
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 `\fBzsh \-c\fP\&',
or even `\fBzsh \-o posixaliases \-c\fP\&', 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\&.
.RE
.TP
\fBPOSIX_BUILTINS\fP <K> <S>
When this option is set the \fBcommand\fP 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 \fBcommand\fP builtin\&.  Special
builtins are
\fB\&.\fP,
\fB:\fP,
\fBbreak\fP,
\fBcontinue\fP,
\fBdeclare\fP,
\fBeval\fP,
\fBexit\fP,
\fBexport\fP,
\fBinteger\fP,
\fBlocal\fP,
\fBreadonly\fP,
\fBreturn\fP,
\fBset\fP,
\fBshift\fP,
\fBsource\fP,
\fBtimes\fP,
\fBtrap\fP and
\fBunset\fP\&.
.TP
\fBPOSIX_IDENTIFIERS\fP <K> <S>
When this option is set, only the ASCII characters \fBa\fP to \fBz\fP, \fBA\fP to
\fBZ\fP, \fB0\fP to \fB9\fP and \fB_\fP may be used in identifiers (names
of shell parameters and modules)\&.
.RS
.PP
When the option is unset and multibyte character support is enabled (i\&.e\&. it
is compiled in and the option \fBMULTIBYTE\fP is set), then additionally any
alphanumeric characters in the local character set may be used in
identifiers\&.  Note that scripts and functions written with this feature are
not portable, and also that both options must be set before the script
or function is parsed; setting them during execution is not sufficient
as the syntax \fIvariable\fP\fB=\fP\fIvalue\fP has already been parsed as
a command rather than an assignment\&.
.PP
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\&.
.RE
.TP
\fBPOSIX_STRINGS\fP <K> <S>
This option affects processing of quoted strings\&.  Currently it only
affects the behaviour of null characters, i\&.e\&. character 0 in the
portable character set corresponding to US ASCII\&.
.RS
.PP
When this option is not set, null characters embedded within strings
of the form \fB$\&'\fP\fI\&.\&.\&.\fP\fB'\fP 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\&.
.PP
When this option is set, the \fB$\&'\fP\fI\&.\&.\&.\fP\fB'\fP expression is truncated at
the null character\&.  Note that remaining parts of the same string
beyond the termination of the quotes are not trunctated\&.
.PP
For example, the command line argument \fBa$\&'b\e0c'd\fP is treated with
the option off as the characters \fBa\fP, \fBb\fP, null, \fBc\fP, \fBd\fP,
and with the option on as the characters \fBa\fP, \fBb\fP, \fBd\fP\&.
.RE
.TP
\fBPOSIX_TRAPS\fP <K> <S>
When the is option is set, the usual zsh behaviour of executing
traps for \fBEXIT\fP on exit from shell functions is suppressed\&.
In that case, manipulating \fBEXIT\fP traps always alters the global
trap for exiting the shell; the \fBLOCAL_TRAPS\fP option is
ignored for the \fBEXIT\fP trap\&.
.TP
\fBSH_FILE_EXPANSION\fP <K> <S>
Perform filename expansion (e\&.g\&., ~ expansion) \fIbefore\fP
parameter expansion, command substitution, arithmetic expansion
and brace expansion\&.
If this option is unset, it is performed \fIafter\fP
brace expansion, so things like `\fB~$USERNAME\fP\&' and
`\fB~{pfalstad,rc}\fP\&' will work\&.
.TP
\fBSH_NULLCMD\fP <K> <S>
Do not use the values of \fBNULLCMD\fP and \fBREADNULLCMD\fP 
when doing redirections, use `\fB:\fP\&' instead (see the section `Redirection')\&.
.TP
\fBSH_OPTION_LETTERS\fP <K> <S>
If this option is set the shell tries to interpret single letter options
(which are used with \fBset\fP and \fBsetopt\fP) like \fBksh\fP does\&.
This also affects the value of the \fB\-\fP special parameter\&.
.TP
\fBSH_WORD_SPLIT\fP (\fB\-y\fP) <K> <S>
Causes field splitting to be performed on unquoted parameter expansions\&.
Note that this option has nothing to do with word splitting\&.
(See the section `Parameter Expansion\&'\&.)
.TP
\fBTRAPS_ASYNC\fP
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\&.
.PP
.SS "Shell State"
.PD 0
.TP
.PD
\fBINTERACTIVE\fP (\fB\-i\fP, ksh: \fB\-i\fP)
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 \fBSHIN_STDIN\fP\&.)
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\&.
.TP
\fBLOGIN\fP (\fB\-l\fP, ksh: \fB\-l\fP)
This is a login shell\&.
If this option is not explicitly set, the shell is a login shell if
the first character of the \fBargv[0]\fP passed to the shell is a `\fB\-\fP\&'\&.
.TP
\fBPRIVILEGED\fP (\fB\-p\fP, ksh: \fB\-p\fP)
Turn on privileged mode\&. This is enabled automatically on startup if the
effective user (group) ID is not equal to the real user (group) ID\&.  Turning
this option off causes the effective user and group IDs to be set to the
real user and group IDs\&. This option disables sourcing user startup files\&.
If zsh is invoked as `\fBsh\fP\&' or `\fBksh\fP' with this option set,
\fB/etc/suid_profile\fP is sourced (after \fB/etc/profile\fP on interactive
shells)\&. Sourcing \fB~/\&.profile\fP is disabled and the contents of the
\fBENV\fP variable is ignored\&. This option cannot be changed using the
\fB\-m\fP option of \fBsetopt\fP and \fBunsetopt\fP, and changing it inside a
function always changes it globally regardless of the \fBLOCAL_OPTIONS\fP
option\&.
.TP
\fBRESTRICTED\fP (\fB\-r\fP)
Enables restricted mode\&.  This option cannot be changed using
\fBunsetopt\fP, and setting it inside a function always changes it
globally regardless of the \fBLOCAL_OPTIONS\fP option\&.  See
the section `Restricted Shell\&'\&.
.TP
\fBSHIN_STDIN\fP (\fB\-s\fP, ksh: \fB\-s\fP)
Commands are being read from the standard input\&.
Commands are read from standard input if no command is specified with
\fB\-c\fP and no file of commands is specified\&.  If \fBSHIN_STDIN\fP
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 on not commands are
\fIactually\fP 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\&.
.TP
\fBSINGLE_COMMAND\fP (\fB\-t\fP, ksh: \fB\-t\fP)
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
\fBINTERACTIVE\fP 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\&.
.PP
.SS "Zle"
.PD 0
.TP
.PD
\fBBEEP\fP (\fB+B\fP) <D>
Beep on error in ZLE\&.
.TP
\fBCOMBINING_CHARS\fP
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\&.
.RS
.PP
If this option is set, the pattern test \fB[[:WORD:]]\fP 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\&.
.RE
.TP
\fBEMACS\fP
If ZLE is loaded, turning on this option has the equivalent effect
of `\fBbindkey \-e\fP\&'\&.  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; \fBbindkey\fP is the recommended interface\&.
.TP
\fBOVERSTRIKE\fP
Start up the line editor in overstrike mode\&.
.TP
\fBSINGLE_LINE_ZLE\fP (\fB\-M\fP) <K>
Use single\-line command line editing instead of multi\-line\&.
.RS
.PP
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\&.
.RE
.TP
\fBVI\fP
If ZLE is loaded, turning on this option has the equivalent effect
of `\fBbindkey \-v\fP\&'\&.  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; \fBbindkey\fP is the recommended interface\&.
.TP
\fBZLE\fP (\fB\-Z\fP)
Use the zsh line editor\&.  Set by default in interactive shells connected to
a terminal\&.
.PP
.SH "OPTION ALIASES"
Some options have alternative names\&.  These aliases are never used for
output, but can be used just like normal option names when specifying
options to the shell\&.
.PP
.PD 0
.TP
.PD
\fBBRACE_EXPAND\fP
\fINO_\fP\fBIGNORE_BRACES\fP
(ksh and bash compatibility)
.TP
\fBDOT_GLOB\fP
\fBGLOB_DOTS\fP
(bash compatibility)
.TP
\fBHASH_ALL\fP
\fBHASH_CMDS\fP
(bash compatibility)
.TP
\fBHIST_APPEND\fP
\fBAPPEND_HISTORY\fP
(bash compatibility)
.TP
\fBHIST_EXPAND\fP
\fBBANG_HIST\fP
(bash compatibility)
.TP
\fBLOG\fP
\fINO_\fP\fBHIST_NO_FUNCTIONS\fP
(ksh compatibility)
.TP
\fBMAIL_WARN\fP
\fBMAIL_WARNING\fP
(bash compatibility)
.TP
\fBONE_CMD\fP
\fBSINGLE_COMMAND\fP
(bash compatibility)
.TP
\fBPHYSICAL\fP
\fBCHASE_LINKS\fP
(ksh and bash compatibility)
.TP
\fBPROMPT_VARS\fP
\fBPROMPT_SUBST\fP
(bash compatibility)
.TP
\fBSTDIN\fP
\fBSHIN_STDIN\fP
(ksh compatibility)
.TP
\fBTRACK_ALL\fP
\fBHASH_CMDS\fP
(ksh compatibility)
.SH "SINGLE LETTER OPTIONS"
.SS "Default set"
.PD 0
.TP
\fB\-0\fP
CORRECT
.TP
\fB\-1\fP
PRINT_EXIT_VALUE
.TP
\fB\-2\fP
\fINO_\fPBAD_PATTERN
.TP
\fB\-3\fP
\fINO_\fPNOMATCH
.TP
\fB\-4\fP
GLOB_DOTS
.TP
\fB\-5\fP
NOTIFY
.TP
\fB\-6\fP
BG_NICE
.TP
\fB\-7\fP
IGNORE_EOF
.TP
\fB\-8\fP
MARK_DIRS
.TP
\fB\-9\fP
AUTO_LIST
.TP
\fB\-B\fP
\fINO_\fPBEEP
.TP
\fB\-C\fP
\fINO_\fPCLOBBER
.TP
\fB\-D\fP
PUSHD_TO_HOME
.TP
\fB\-E\fP
PUSHD_SILENT
.TP
\fB\-F\fP
\fINO_\fPGLOB
.TP
\fB\-G\fP
NULL_GLOB
.TP
\fB\-H\fP
RM_STAR_SILENT
.TP
\fB\-I\fP
IGNORE_BRACES
.TP
\fB\-J\fP
AUTO_CD
.TP
\fB\-K\fP
\fINO_\fPBANG_HIST
.TP
\fB\-L\fP
SUN_KEYBOARD_HACK
.TP
\fB\-M\fP
SINGLE_LINE_ZLE
.TP
\fB\-N\fP
AUTO_PUSHD
.TP
\fB\-O\fP
CORRECT_ALL
.TP
\fB\-P\fP
RC_EXPAND_PARAM
.TP
\fB\-Q\fP
PATH_DIRS
.TP
\fB\-R\fP
LONG_LIST_JOBS
.TP
\fB\-S\fP
REC_EXACT
.TP
\fB\-T\fP
CDABLE_VARS
.TP
\fB\-U\fP
MAIL_WARNING
.TP
\fB\-V\fP
\fINO_\fPPROMPT_CR
.TP
\fB\-W\fP
AUTO_RESUME
.TP
\fB\-X\fP
LIST_TYPES
.TP
\fB\-Y\fP
MENU_COMPLETE
.TP
\fB\-Z\fP
ZLE
.TP
\fB\-a\fP
ALL_EXPORT
.TP
\fB\-e\fP
ERR_EXIT
.TP
\fB\-f\fP
\fINO_\fPRCS
.TP
\fB\-g\fP
HIST_IGNORE_SPACE
.TP
\fB\-h\fP
HIST_IGNORE_DUPS
.TP
\fB\-i\fP
INTERACTIVE
.TP
\fB\-k\fP
INTERACTIVE_COMMENTS
.TP
\fB\-l\fP
LOGIN
.TP
\fB\-m\fP
MONITOR
.TP
\fB\-n\fP
\fINO_\fPEXEC
.TP
\fB\-p\fP
PRIVILEGED
.TP
\fB\-r\fP
RESTRICTED
.TP
\fB\-s\fP
SHIN_STDIN
.TP
\fB\-t\fP
SINGLE_COMMAND
.TP
\fB\-u\fP
\fINO_\fPUNSET
.TP
\fB\-v\fP
VERBOSE
.TP
\fB\-w\fP
CHASE_LINKS
.TP
\fB\-x\fP
XTRACE
.TP
\fB\-y\fP
SH_WORD_SPLIT
.PD
.SS "sh/ksh emulation set"
.PD 0
.TP
\fB\-C\fP
\fINO_\fPCLOBBER
.TP
\fB\-T\fP
TRAPS_ASYNC
.TP
\fB\-X\fP
MARK_DIRS
.TP
\fB\-a\fP
ALL_EXPORT
.TP
\fB\-b\fP
NOTIFY
.TP
\fB\-e\fP
ERR_EXIT
.TP
\fB\-f\fP
\fINO_\fPGLOB
.TP
\fB\-i\fP
INTERACTIVE
.TP
\fB\-l\fP
LOGIN
.TP
\fB\-m\fP
MONITOR
.TP
\fB\-n\fP
\fINO_\fPEXEC
.TP
\fB\-p\fP
PRIVILEGED
.TP
\fB\-r\fP
RESTRICTED
.TP
\fB\-s\fP
SHIN_STDIN
.TP
\fB\-t\fP
SINGLE_COMMAND
.TP
\fB\-u\fP
\fINO_\fPUNSET
.TP
\fB\-v\fP
VERBOSE
.TP
\fB\-x\fP
XTRACE
.PD
.SS "Also note"
.PD 0
.TP
\fB\-A\fP
Used by \fBset\fP for setting arrays
.TP
\fB\-b\fP
Used on the command line to specify end of option processing
.TP
\fB\-c\fP
Used on the command line to specify a single command
.TP
\fB\-m\fP
Used by \fBsetopt\fP for pattern\-matching option setting
.TP
\fB\-o\fP
Used in all places to allow use of long option names
.TP
\fB\-s\fP
Used by \fBset\fP to sort positional parameters
.PD