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ZSHPARAM(1) General Commands Manual ZSHPARAM(1)

NAME
zshparam - zsh parameters

DESCRIPTION
A parameter has a name, a value, and a number of attributes. A name may be any sequence of
alphanumeric characters and underscores, or the single characters `*', `@', `#', `?', `-',
`$', or `!'. A parameter whose name begins with an alphanumeric or underscore is also re‐
ferred to as a variable.

The attributes of a parameter determine the type of its value, often referred to as the para‐
meter type or variable type, and also control other processing that may be applied to the
value when it is referenced. The value type may be a scalar (a string, an integer, or a
floating point number), an array (indexed numerically), or an associative array (an unordered
set of name-value pairs, indexed by name, also referred to as a hash).

Named scalar parameters may have the exported, -x, attribute, to copy them into the process
environment, which is then passed from the shell to any new processes that it starts. Ex‐
ported parameters are called environment variables. The shell also imports environment vari‐
ables at startup time and automatically marks the corresponding parameters as exported. Some
environment variables are not imported for reasons of security or because they would inter‐
fere with the correct operation of other shell features.

Parameters may also be special, that is, they have a predetermined meaning to the shell.
Special parameters cannot have their type changed or their readonly attribute turned off, and
if a special parameter is unset, then later recreated, the special properties will be re‐
tained.

To declare the type of a parameter, or to assign a string or numeric value to a scalar para‐
meter, use the typeset builtin.

The value of a scalar parameter may also be assigned by writing:

name=value

In scalar assignment, value is expanded as a single string, in which the elements of arrays
are joined together; filename expansion is not performed unless the option GLOB_ASSIGN is
set.

When the integer attribute, -i, or a floating point attribute, -E or -F, is set for name, the
value is subject to arithmetic evaluation. Furthermore, by replacing `=' with `+=', a para‐
meter can be incremented or appended to. See the section `Array Parameters' and Arithmetic
Evaluation (in zshmisc(1)) for additional forms of assignment.

Note that assignment may implicitly change the attributes of a parameter. For example, as‐
signing a number to a variable in arithmetic evaluation may change its type to integer or
float, and with GLOB_ASSIGN assigning a pattern to a variable may change its type to an ar‐
ray.

To reference the value of a parameter, write `$name' or `${name}'. See Parameter Expansion
in zshexpn(1) for complete details. That section also explains the effect of the difference
between scalar and array assignment on parameter expansion.

ARRAY PARAMETERS
To assign an array value, write one of:

set -A name value ...
name=(value ...)
name=([key]=value ...)

If no parameter name exists, an ordinary array parameter is created. If the parameter name
exists and is a scalar, it is replaced by a new array.

In the third form, key is an expression that will be evaluated in arithmetic context (in its
simplest form, an integer) that gives the index of the element to be assigned with value. In
this form any elements not explicitly mentioned that come before the largest index to which a
value is assigned are assigned an empty string. The indices may be in any order. Note that
this syntax is strict: [ and ]= must not be quoted, and key may not consist of the unquoted
string ]=, but is otherwise treated as a simple string. The enhanced forms of subscript ex‐
pression that may be used when directly subscripting a variable name, described in the sec‐
tion `Array Subscripts' below, are not available.

The syntaxes with and without the explicit key may be mixed. An implicit key is deduced by
incrementing the index from the previously assigned element. Note that it is not treated as
an error if latter assignments in this form overwrite earlier assignments.

For example, assuming the option KSH_ARRAYS is not set, the following:

array=(one [3]=three four)

causes the array variable array to contain four elements one, an empty string, three and
four, in that order.

In the forms where only value is specified, full command line expansion is performed.

In the [key]=value form, both key and value undergo all forms of expansion allowed for single
word shell expansions (this does not include filename generation); these are as performed by
the parameter expansion flag (e) as described in zshexpn(1). Nested parentheses may surround
value and are included as part of the value, which is joined into a plain string; this dif‐
fers from ksh which allows the values themselves to be arrays. A future version of zsh may
support that. To cause the brackets to be interpreted as a character class for filename gen‐
eration, and therefore to treat the resulting list of files as a set of values, quote the
equal sign using any form of quoting. Example:

name=([a-z]'='*)

To append to an array without changing the existing values, use one of the following:

name+=(value ...)
name+=([key]=value ...)

In the second form key may specify an existing index as well as an index off the end of the
old array; any existing value is overwritten by value. Also, it is possible to use
[key]+=value to append to the existing value at that index.

Within the parentheses on the right hand side of either form of the assignment, newlines and
semicolons are treated the same as white space, separating individual values. Any consecu‐
tive sequence of such characters has the same effect.

Ordinary array parameters may also be explicitly declared with:

typeset -a name

Associative arrays must be declared before assignment, by using:

typeset -A name

When name refers to an associative array, the list in an assignment is interpreted as alter‐
nating keys and values:

set -A name key value ...
name=(key value ...)
name=([key]=value ...)

Note that only one of the two syntaxes above may be used in any given assignment; the forms
may not be mixed. This is unlike the case of numerically indexed arrays.

Every key must have a value in this case. Note that this assigns to the entire array, delet‐
ing any elements that do not appear in the list. The append syntax may also be used with an
associative array:

name+=(key value ...)
name+=([key]=value ...)

This adds a new key/value pair if the key is not already present, and replaces the value for
the existing key if it is. In the second form it is also possible to use [key]+=value to ap‐
pend to the existing value at that key. Expansion is performed identically to the corre‐
sponding forms for normal arrays, as described above.

To create an empty array (including associative arrays), use one of:

set -A name
name=()

Array Subscripts
Individual elements of an array may be selected using a subscript. A subscript of the form
`[exp]' selects the single element exp, where exp is an arithmetic expression which will be
subject to arithmetic expansion as if it were surrounded by `$((...))'. The elements are
numbered beginning with 1, unless the KSH_ARRAYS option is set in which case they are num‐
bered from zero.

Subscripts may be used inside braces used to delimit a parameter name, thus `${foo[2]}' is
equivalent to `$foo[2]'. If the KSH_ARRAYS option is set, the braced form is the only one
that works, as bracketed expressions otherwise are not treated as subscripts.

If the KSH_ARRAYS option is not set, then by default accesses to an array element with a sub‐
script that evaluates to zero return an empty string, while an attempt to write such an ele‐
ment is treated as an error. For backward compatibility the KSH_ZERO_SUBSCRIPT option can be
set to cause subscript values 0 and 1 to be equivalent; see the description of the option in
zshoptions(1).

The same subscripting syntax is used for associative arrays, except that no arithmetic expan‐
sion is applied to exp. However, the parsing rules for arithmetic expressions still apply,
which affects the way that certain special characters must be protected from interpretation.
See Subscript Parsing below for details.

A subscript of the form `[*]' or `[@]' evaluates to all elements of an array; there is no
difference between the two except when they appear within double quotes. `"$foo[*]"' evalu‐
ates to `"$foo[1] $foo[2] ..."', whereas `"$foo[@]"' evaluates to `"$foo[1]" "$foo[2]" ...'.
For associative arrays, `[*]' or `[@]' evaluate to all the values, in no particular order.
Note that this does not substitute the keys; see the documentation for the `k' flag under Pa‐
rameter Expansion Flags in zshexpn(1) for complete details. When an array parameter is ref‐
erenced as `$name' (with no subscript) it evaluates to `$name[*]', unless the KSH_ARRAYS op‐
tion is set in which case it evaluates to `${name[0]}' (for an associative array, this means
the value of the key `0', which may not exist even if there are values for other keys).

A subscript of the form `[exp1,exp2]' selects all elements in the range exp1 to exp2, inclu‐
sive. (Associative arrays are unordered, and so do not support ranges.) If one of the sub‐
scripts evaluates to a negative number, say -n, then the nth element from the end of the ar‐
ray is used. Thus `$foo[-3]' is the third element from the end of the array foo, and
`$foo[1,-1]' is the same as `$foo[*]'.

Subscripting may also be performed on non-array values, in which case the subscripts specify
a substring to be extracted. For example, if FOO is set to `foobar', then `echo $FOO[2,5]'
prints `ooba'. Note that some forms of subscripting described below perform pattern match‐
ing, and in that case the substring extends from the start of the match of the first sub‐
script to the end of the match of the second subscript. For example,

string="abcdefghijklm"
print ${string[(r)d?,(r)h?]}

prints `defghi'. This is an obvious generalisation of the rule for single-character matches.
For a single subscript, only a single character is referenced (not the range of characters
covered by the match).

Note that in substring operations the second subscript is handled differently by the r and R
subscript flags: the former takes the shortest match as the length and the latter the longest
match. Hence in the former case a * at the end is redundant while in the latter case it
matches the whole remainder of the string. This does not affect the result of the single
subscript case as here the length of the match is irrelevant.

Array Element Assignment
A subscript may be used on the left side of an assignment like so:

name[exp]=value

In this form of assignment the element or range specified by exp is replaced by the expres‐
sion on the right side. An array (but not an associative array) may be created by assignment
to a range or element. Arrays do not nest, so assigning a parenthesized list of values to an
element or range changes the number of elements in the array, shifting the other elements to
accommodate the new values. (This is not supported for associative arrays.)

This syntax also works as an argument to the typeset command:

typeset "name[exp]"=value

The value may not be a parenthesized list in this case; only single-element assignments may
be made with typeset. Note that quotes are necessary in this case to prevent the brackets
from being interpreted as filename generation operators. The noglob precommand modifier
could be used instead.

To delete an element of an ordinary array, assign `()' to that element. To delete an element
of an associative array, use the unset command:

unset "name[exp]"

Subscript Flags
If the opening bracket, or the comma in a range, in any subscript expression is directly fol‐
lowed by an opening parenthesis, the string up to the matching closing one is considered to
be a list of flags, as in `name[(flags)exp]'.

The flags s, n and b take an argument; the delimiter is shown below as `:', but any charac‐
ter, or the matching pairs `(...)', `{...}', `[...]', or `<...>', may be used, but note that
`<...>' can only be used if the subscript is inside a double quoted expression or a parameter
substitution enclosed in braces as otherwise the expression is interpreted as a redirection.

The flags currently understood are:

w If the parameter subscripted is a scalar then this flag makes subscripting work on
words instead of characters. The default word separator is whitespace. When combined
with the i or I flag, the effect is to produce the index of the first character of the
first/last word which matches the given pattern; note that a failed match in this case
always yields 0.

s:string:
This gives the string that separates words (for use with the w flag). The delimiter
character : is arbitrary; see above.

p Recognize the same escape sequences as the print builtin in the string argument of a
subsequent `s' flag.

f If the parameter subscripted is a scalar then this flag makes subscripting work on
lines instead of characters, i.e. with elements separated by newlines. This is a
shorthand for `pws:\n:'.

r Reverse subscripting: if this flag is given, the exp is taken as a pattern and the re‐
sult is the first matching array element, substring or word (if the parameter is an
array, if it is a scalar, or if it is a scalar and the `w' flag is given, respec‐
tively). The subscript used is the number of the matching element, so that pairs of
subscripts such as `$foo[(r)??,3]' and `$foo[(r)??,(r)f*]' are possible if the parame‐
ter is not an associative array. If the parameter is an associative array, only the
value part of each pair is compared to the pattern, and the result is that value.

If a search through an ordinary array failed, the search sets the subscript to one
past the end of the array, and hence ${array[(r)pattern]} will substitute the empty
string. Thus the success of a search can be tested by using the (i) flag, for example
(assuming the option KSH_ARRAYS is not in effect):

[[ ${array[(i)pattern]} -le ${#array} ]]

If KSH_ARRAYS is in effect, the -le should be replaced by -lt.

R Like `r', but gives the last match. For associative arrays, gives all possible
matches. May be used for assigning to ordinary array elements, but not for assigning
to associative arrays. On failure, for normal arrays this has the effect of returning
the element corresponding to subscript 0; this is empty unless one of the options
KSH_ARRAYS or KSH_ZERO_SUBSCRIPT is in effect.

Note that in subscripts with both `r' and `R' pattern characters are active even if
they were substituted for a parameter (regardless of the setting of GLOB_SUBST which
controls this feature in normal pattern matching). The flag `e' can be added to in‐
hibit pattern matching. As this flag does not inhibit other forms of substitution,
care is still required; using a parameter to hold the key has the desired effect:

key2='original key'
print ${array[(Re)$key2]}

i Like `r', but gives the index of the match instead; this may not be combined with a
second argument. On the left side of an assignment, behaves like `r'. For associa‐
tive arrays, the key part of each pair is compared to the pattern, and the first
matching key found is the result. On failure substitutes the length of the array plus
one, as discussed under the description of `r', or the empty string for an associative
array.

Note: Although `i' may be applied to a scalar substitution to find the offset of a
substring, the results are likely to be misleading when searching within substitutions
that yield an empty string, or when searching for the empty substring.

I Like `i', but gives the index of the last match, or all possible matching keys in an
associative array. On failure substitutes 0, or the empty string for an associative
array. This flag is best when testing for values or keys that do not exist.

Note: If the option KSH_ARRAYS is in effect and no match is found, the result is in‐
distinguishable from the case when the first element of the array matches.

k If used in a subscript on an associative array, this flag causes the keys to be inter‐
preted as patterns, and returns the value for the first key found where exp is matched
by the key. Note this could be any such key as no ordering of associative arrays is
defined. This flag does not work on the left side of an assignment to an associative
array element. If used on another type of parameter, this behaves like `r'.

K On an associative array this is like `k' but returns all values where exp is matched
by the keys. On other types of parameters this has the same effect as `R'.

n:expr:
If combined with `r', `R', `i' or `I', makes them give the nth or nth last match (if
expr evaluates to n). This flag is ignored when the array is associative. The delim‐
iter character : is arbitrary; see above.

b:expr:
If combined with `r', `R', `i' or `I', makes them begin at the nth or nth last ele‐
ment, word, or character (if expr evaluates to n). This flag is ignored when the ar‐
ray is associative. The delimiter character : is arbitrary; see above.

e This flag causes any pattern matching that would be performed on the subscript to use
plain string matching instead. Hence `${array[(re)*]}' matches only the array element
whose value is *. Note that other forms of substitution such as parameter substitu‐
tion are not inhibited.

This flag can also be used to force * or @ to be interpreted as a single key rather
than as a reference to all values. It may be used for either purpose on the left side
of an assignment.

See Parameter Expansion Flags (zshexpn(1)) for additional ways to manipulate the results of
array subscripting.

Subscript Parsing
This discussion applies mainly to associative array key strings and to patterns used for re‐
verse subscripting (the `r', `R', `i', etc. flags), but it may also affect parameter substi‐
tutions that appear as part of an arithmetic expression in an ordinary subscript.

To avoid subscript parsing limitations in assignments to associative array elements, use the
append syntax:

aa+=('key with "*strange*" characters' 'value string')

The basic rule to remember when writing a subscript expression is that all text between the
opening `[' and the closing `]' is interpreted as if it were in double quotes (see zsh‐
misc(1)). However, unlike double quotes which normally cannot nest, subscript expressions
may appear inside double-quoted strings or inside other subscript expressions (or both!), so
the rules have two important differences.

The first difference is that brackets (`[' and `]') must appear as balanced pairs in a sub‐
script expression unless they are preceded by a backslash (`\'). Therefore, within a sub‐
script expression (and unlike true double-quoting) the sequence `\[' becomes `[', and simi‐
larly `\]' becomes `]'. This applies even in cases where a backslash is not normally re‐
quired; for example, the pattern `[^[]' (to match any character other than an open bracket)
should be written `[^\[]' in a reverse-subscript pattern. However, note that `\[^\[\]' and
even `\[^[]' mean the same thing, because backslashes are always stripped when they appear
before brackets!

The same rule applies to parentheses (`(' and `)') and braces (`{' and `}'): they must appear
either in balanced pairs or preceded by a backslash, and backslashes that protect parentheses
or braces are removed during parsing. This is because parameter expansions may be surrounded
by balanced braces, and subscript flags are introduced by balanced parentheses.

The second difference is that a double-quote (`"') may appear as part of a subscript expres‐
sion without being preceded by a backslash, and therefore that the two characters `\"' remain
as two characters in the subscript (in true double-quoting, `\"' becomes `"'). However, be‐
cause of the standard shell quoting rules, any double-quotes that appear must occur in bal‐
anced pairs unless preceded by a backslash. This makes it more difficult to write a sub‐
script expression that contains an odd number of double-quote characters, but the reason for
this difference is so that when a subscript expression appears inside true double-quotes, one
can still write `\"' (rather than `\\\"') for `"'.

To use an odd number of double quotes as a key in an assignment, use the typeset builtin and
an enclosing pair of double quotes; to refer to the value of that key, again use double
quotes:

typeset -A aa
typeset "aa[one\"two\"three\"quotes]"=QQQ
print "$aa[one\"two\"three\"quotes]"

It is important to note that the quoting rules do not change when a parameter expansion with
a subscript is nested inside another subscript expression. That is, it is not necessary to
use additional backslashes within the inner subscript expression; they are removed only once,
from the innermost subscript outwards. Parameters are also expanded from the innermost sub‐
script first, as each expansion is encountered left to right in the outer expression.

A further complication arises from a way in which subscript parsing is not different from
double quote parsing. As in true double-quoting, the sequences `\*', and `\@' remain as two
characters when they appear in a subscript expression. To use a literal `*' or `@' as an as‐
sociative array key, the `e' flag must be used:

typeset -A aa
aa[(e)*]=star
print $aa[(e)*]

A last detail must be considered when reverse subscripting is performed. Parameters appear‐
ing in the subscript expression are first expanded and then the complete expression is inter‐
preted as a pattern. This has two effects: first, parameters behave as if GLOB_SUBST were on
(and it cannot be turned off); second, backslashes are interpreted twice, once when parsing
the array subscript and again when parsing the pattern. In a reverse subscript, it's neces‐
sary to use four backslashes to cause a single backslash to match literally in the pattern.
For complex patterns, it is often easiest to assign the desired pattern to a parameter and
then refer to that parameter in the subscript, because then the backslashes, brackets, paren‐
theses, etc., are seen only when the complete expression is converted to a pattern. To match
the value of a parameter literally in a reverse subscript, rather than as a pattern, use
`${(q)name}' (see zshexpn(1)) to quote the expanded value.

Note that the `k' and `K' flags are reverse subscripting for an ordinary array, but are not
reverse subscripting for an associative array! (For an associative array, the keys in the
array itself are interpreted as patterns by those flags; the subscript is a plain string in
that case.)

One final note, not directly related to subscripting: the numeric names of positional parame‐
ters (described below) are parsed specially, so for example `$2foo' is equivalent to
`${2}foo'. Therefore, to use subscript syntax to extract a substring from a positional para‐
meter, the expansion must be surrounded by braces; for example, `${2[3,5]}' evaluates to the
third through fifth characters of the second positional parameter, but `$2[3,5]' is the en‐
tire second parameter concatenated with the filename generation pattern `[3,5]'.

POSITIONAL PARAMETERS
The positional parameters provide access to the command-line arguments of a shell function,
shell script, or the shell itself; see the section `Invocation', and also the section `Func‐
tions'. The parameter n, where n is a number, is the nth positional parameter. The parame‐
ter `$0' is a special case, see the section `Parameters Set By The Shell'.

The parameters *, @ and argv are arrays containing all the positional parameters; thus
`$argv[n]', etc., is equivalent to simply `$n'. Note that the options KSH_ARRAYS or
KSH_ZERO_SUBSCRIPT apply to these arrays as well, so with either of those options set,
`${argv[0]}' is equivalent to `$1' and so on.

Positional parameters may be changed after the shell or function starts by using the set
builtin, by assigning to the argv array, or by direct assignment of the form `n=value' where
n is the number of the positional parameter to be changed. This also creates (with empty
values) any of the positions from 1 to n that do not already have values. Note that, because
the positional parameters form an array, an array assignment of the form `n=(value ...)' is
allowed, and has the effect of shifting all the values at positions greater than n by as many
positions as necessary to accommodate the new values.

LOCAL PARAMETERS
Shell function executions delimit scopes for shell parameters. (Parameters are dynamically
scoped.) The typeset builtin, and its alternative forms declare, integer, local and readonly
(but not export), can be used to declare a parameter as being local to the innermost scope.

When a parameter is read or assigned to, the innermost existing parameter of that name is
used. (That is, the local parameter hides any less-local parameter.) However, assigning to
a non-existent parameter, or declaring a new parameter with export, causes it to be created
in the outermost scope.

Local parameters disappear when their scope ends. unset can be used to delete a parameter
while it is still in scope; any outer parameter of the same name remains hidden.

Special parameters may also be made local; they retain their special attributes unless either
the existing or the newly-created parameter has the -h (hide) attribute. This may have unex‐
pected effects: there is no default value, so if there is no assignment at the point the
variable is made local, it will be set to an empty value (or zero in the case of integers).
The following:

typeset PATH=/new/directory:$PATH

is valid for temporarily allowing the shell or programmes called from it to find the programs
in /new/directory inside a function.

Note that the restriction in older versions of zsh that local parameters were never exported
has been removed.

PARAMETERS SET BY THE SHELL
In the parameter lists that follow, the mark `<S>' indicates that the parameter is special.
`<Z>' indicates that the parameter does not exist when the shell initializes in sh or ksh em‐
ulation mode.

The parameters `!', `#', `*', `-', `?', `@', `$', `ARGC', `HISTCMD', `LINENO', `PPID', `sta‐
tus', `TTYIDLE', `zsh_eval_context', `ZSH_EVAL_CONTEXT', and `ZSH_SUBSHELL' are read-only and
thus cannot be restored by the user, so they are not output by `typeset -p'. This also ap‐
plies to many read-only parameters loaded from modules.

The following parameters are automatically set by the shell:

! <S> The process ID of the last command started in the background with &, put into the
background with the bg builtin, or spawned with coproc.

# <S> The number of positional parameters in decimal. Note that some confusion may occur
with the syntax $#param which substitutes the length of param. Use ${#} to resolve
ambiguities. In particular, the sequence `$#-...' in an arithmetic expression is in‐
terpreted as the length of the parameter -, q.v.

ARGC <S> <Z>
Same as #.

$ <S> The process ID of this shell, set when the shell initializes. Processes forked from
the shell without executing a new program, such as command substitutions and commands
grouped with (...), are subshells that duplicate the current shell, and thus substi‐
tute the same value for $$ as their parent shell.

- <S> Flags supplied to the shell on invocation or by the set or setopt commands.

* <S> An array containing the positional parameters.

argv <S> <Z>
Same as *. Assigning to argv changes the local positional parameters, but argv is not
itself a local parameter. Deleting argv with unset in any function deletes it every‐
where, although only the innermost positional parameter array is deleted (so * and @
in other scopes are not affected).

@ <S> Same as argv[@], even when argv is not set.

? <S> The exit status returned by the last command.

0 <S> The name used to invoke the current shell, or as set by the -c command line option
upon invocation. If the FUNCTION_ARGZERO option is set, $0 is set upon entry to a
shell function to the name of the function, and upon entry to a sourced script to the
name of the script, and reset to its previous value when the function or script re‐
turns.

status <S> <Z>
Same as ?.

pipestatus <S> <Z>
An array containing the exit statuses returned by all commands in the last pipeline.

_ <S> The last argument of the previous command. Also, this parameter is set in the envi‐
ronment of every command executed to the full pathname of the command.

CPUTYPE
The machine type (microprocessor class or machine model), as determined at run time.

EGID <S>
The effective group ID of the shell process. If you have sufficient privileges, you
may change the effective group ID of the shell process by assigning to this parameter.
Also (assuming sufficient privileges), you may start a single command with a different
effective group ID by `(EGID=gid; command)'

If this is made local, it is not implicitly set to 0, but may be explicitly set lo‐
cally.

EUID <S>
The effective user ID of the shell process. If you have sufficient privileges, you
may change the effective user ID of the shell process by assigning to this parameter.
Also (assuming sufficient privileges), you may start a single command with a different
effective user ID by `(EUID=uid; command)'

If this is made local, it is not implicitly set to 0, but may be explicitly set lo‐
cally.

ERRNO <S>
The value of errno (see errno(3)) as set by the most recently failed system call.
This value is system dependent and is intended for debugging purposes. It is also
useful with the zsh/system module which allows the number to be turned into a name or
message.

To use this parameter, it must first be assigned a value (typically 0 (zero)). It is
initially unset for scripting compatibility.

FUNCNEST <S>
Integer. If greater than or equal to zero, the maximum nesting depth of shell func‐
tions. When it is exceeded, an error is raised at the point where a function is
called. The default value is determined when the shell is configured, but is typi‐
cally 500. Increasing the value increases the danger of a runaway function recursion
causing the shell to crash. Setting a negative value turns off the check.

GID <S>
The real group ID of the shell process. If you have sufficient privileges, you may
change the group ID of the shell process by assigning to this parameter. Also (assum‐
ing sufficient privileges), you may start a single command under a different group ID
by `(GID=gid; command)'

If this is made local, it is not implicitly set to 0, but may be explicitly set lo‐
cally.

HISTCMD
The current history event number in an interactive shell, in other words the event
number for the command that caused $HISTCMD to be read. If the current history event
modifies the history, HISTCMD changes to the new maximum history event number.

HOST The current hostname.

LINENO <S>
The line number of the current line within the current script, sourced file, or shell
function being executed, whichever was started most recently. Note that in the case
of shell functions the line number refers to the function as it appeared in the origi‐
nal definition, not necessarily as displayed by the functions builtin.

LOGNAME
If the corresponding variable is not set in the environment of the shell, it is ini‐
tialized to the login name corresponding to the current login session. This parameter
is exported by default but this can be disabled using the typeset builtin. The value
is set to the string returned by the getlogin(3) system call if that is available.

MACHTYPE
The machine type (microprocessor class or machine model), as determined at compile
time.

OLDPWD The previous working directory. This is set when the shell initializes and whenever
the directory changes.

OPTARG <S>
The value of the last option argument processed by the getopts command.

OPTIND <S>
The index of the last option argument processed by the getopts command.

OSTYPE The operating system, as determined at compile time.

PPID <S>
The process ID of the parent of the shell, set when the shell initializes. As with
$$, the value does not change in subshells created as a duplicate of the current
shell.

PWD The present working directory. This is set when the shell initializes and whenever
the directory changes.

RANDOM <S>
A pseudo-random integer from 0 to 32767, newly generated each time this parameter is
referenced. The random number generator can be seeded by assigning a numeric value to
RANDOM.

The values of RANDOM form an intentionally-repeatable pseudo-random sequence; sub‐
shells that reference RANDOM will result in identical pseudo-random values unless the
value of RANDOM is referenced or seeded in the parent shell in between subshell invo‐
cations.

SECONDS <S>
The number of seconds since shell invocation. If this parameter is assigned a value,
then the value returned upon reference will be the value that was assigned plus the
number of seconds since the assignment.

Unlike other special parameters, the type of the SECONDS parameter can be changed us‐
ing the typeset command. The type may be changed only to one of the floating point
types or back to integer. For example, `typeset -F SECONDS' causes the value to be
reported as a floating point number. The value is available to microsecond accuracy,
although the shell may show more or fewer digits depending on the use of typeset. See
the documentation for the builtin typeset in zshbuiltins(1) for more details.

SHLVL <S>
Incremented by one each time a new shell is started.

signals
An array containing the names of the signals. Note that with the standard zsh number‐
ing of array indices, where the first element has index 1, the signals are offset by 1
from the signal number used by the operating system. For example, on typical
Unix-like systems HUP is signal number 1, but is referred to as $signals[2]. This is
because of EXIT at position 1 in the array, which is used internally by zsh but is not
known to the operating system.

TRY_BLOCK_ERROR <S>
In an always block, indicates whether the preceding list of code caused an error. The
value is 1 to indicate an error, 0 otherwise. It may be reset, clearing the error
condition. See Complex Commands in zshmisc(1)

TRY_BLOCK_INTERRUPT <S>
This variable works in a similar way to TRY_BLOCK_ERROR, but represents the status of
an interrupt from the signal SIGINT, which typically comes from the keyboard when the
user types ^C. If set to 0, any such interrupt will be reset; otherwise, the inter‐
rupt is propagated after the always block.

Note that it is possible that an interrupt arrives during the execution of the always
block; this interrupt is also propagated.

TTY The name of the tty associated with the shell, if any.

TTYIDLE <S>
The idle time of the tty associated with the shell in seconds or -1 if there is no
such tty.

UID <S>
The real user ID of the shell process. If you have sufficient privileges, you may
change the user ID of the shell by assigning to this parameter. Also (assuming suffi‐
cient privileges), you may start a single command under a different user ID by
`(UID=uid; command)'

If this is made local, it is not implicitly set to 0, but may be explicitly set lo‐
cally.

USERNAME <S>
The username corresponding to the real user ID of the shell process. If you have suf‐
ficient privileges, you may change the username (and also the user ID and group ID) of
the shell by assigning to this parameter. Also (assuming sufficient privileges), you
may start a single command under a different username (and user ID and group ID) by
`(USERNAME=username; command)'

VENDOR The vendor, as determined at compile time.

zsh_eval_context <S> <Z> (ZSH_EVAL_CONTEXT <S>)
An array (colon-separated list) indicating the context of shell code that is being
run. Each time a piece of shell code that is stored within the shell is executed a
string is temporarily appended to the array to indicate the type of operation that is
being performed. Read in order the array gives an indication of the stack of opera‐
tions being performed with the most immediate context last.

Note that the variable does not give information on syntactic context such as
pipelines or subshells. Use $ZSH_SUBSHELL to detect subshells.

The context is one of the following:
cmdarg Code specified by the -c option to the command line that invoked the shell.

cmdsubst
Command substitution using the `...` or $(...) construct.

equalsubst
File substitution using the =(...) construct.

eval Code executed by the eval builtin.

evalautofunc
Code executed with the KSH_AUTOLOAD mechanism in order to define an autoloaded
function.

fc Code from the shell history executed by the -e option to the fc builtin.

file Lines of code being read directly from a file, for example by the source
builtin.

filecode
Lines of code being read from a .zwc file instead of directly from the source
file.

globqual
Code executed by the e or + glob qualifier.

globsort
Code executed to order files by the o glob qualifier.

insubst
File substitution using the <(...) construct.

loadautofunc
Code read directly from a file to define an autoloaded function.

outsubst
File substitution using the >(...) construct.

sched Code executed by the sched builtin.

shfunc A shell function.

stty Code passed to stty by the STTY environment variable. Normally this is passed
directly to the system's stty command, so this value is unlikely to be seen in
practice.

style Code executed as part of a style retrieved by the zstyle builtin from the
zsh/zutil module.

toplevel
The highest execution level of a script or interactive shell.

trap Code executed as a trap defined by the trap builtin. Traps defined as func‐
tions have the context shfunc. As traps are asynchronous they may have a dif‐
ferent hierarchy from other code.

zpty Code executed by the zpty builtin from the zsh/zpty module.

zregexparse-guard
Code executed as a guard by the zregexparse command from the zsh/zutil module.

zregexparse-action
Code executed as an action by the zregexparse command from the zsh/zutil mod‐
ule.

ZSH_ARGZERO
If zsh was invoked to run a script, this is the name of the script. Otherwise, it is
the name used to invoke the current shell. This is the same as the value of $0 when
the POSIX_ARGZERO option is set, but is always available.

ZSH_EXECUTION_STRING
If the shell was started with the option -c, this contains the argument passed to the
option. Otherwise it is not set.

ZSH_NAME
Expands to the basename of the command used to invoke this instance of zsh.

ZSH_PATCHLEVEL
The output of `git describe --tags --long' for the zsh repository used to build the
shell. This is most useful in order to keep track of versions of the shell during de‐
velopment between releases; hence most users should not use it and should instead rely
on $ZSH_VERSION.

zsh_scheduled_events
See the section `The zsh/sched Module' in zshmodules(1).

ZSH_SCRIPT
If zsh was invoked to run a script, this is the name of the script, otherwise it is
unset.

ZSH_SUBSHELL
Readonly integer. Initially zero, incremented each time the shell forks to create a
subshell for executing code. Hence `(print $ZSH_SUBSHELL)' and `print $(print
$ZSH_SUBSHELL)' output 1, while `( (print $ZSH_SUBSHELL) )' outputs 2.

ZSH_VERSION
The version number of the release of zsh.

PARAMETERS USED BY THE SHELL
The following parameters are used by the shell. Again, `<S>' indicates that the parameter is
special and `<Z>' indicates that the parameter does not exist when the shell initializes in
sh or ksh emulation mode.

In cases where there are two parameters with an upper- and lowercase form of the same name,
such as path and PATH, the lowercase form is an array and the uppercase form is a scalar with
the elements of the array joined together by colons. These are similar to tied parameters
created via `typeset -T'. The normal use for the colon-separated form is for exporting to
the environment, while the array form is easier to manipulate within the shell. Note that
unsetting either of the pair will unset the other; they retain their special properties when
recreated, and recreating one of the pair will recreate the other.

ARGV0 If exported, its value is used as the argv[0] of external commands. Usually used in
constructs like `ARGV0=emacs nethack'.

BAUD The rate in bits per second at which data reaches the terminal. The line editor will
use this value in order to compensate for a slow terminal by delaying updates to the
display until necessary. If the parameter is unset or the value is zero the compensa‐
tion mechanism is turned off. The parameter is not set by default.

This parameter may be profitably set in some circumstances, e.g. for slow modems di‐
aling into a communications server, or on a slow wide area network. It should be set
to the baud rate of the slowest part of the link for best performance.

cdpath <S> <Z> (CDPATH <S>)
An array (colon-separated list) of directories specifying the search path for the cd
command.

COLUMNS <S>
The number of columns for this terminal session. Used for printing select lists and
for the line editor.

CORRECT_IGNORE
If set, is treated as a pattern during spelling correction. Any potential correction
that matches the pattern is ignored. For example, if the value is `_*' then comple‐
tion functions (which, by convention, have names beginning with `_') will never be of‐
fered as spelling corrections. The pattern does not apply to the correction of file
names, as applied by the CORRECT_ALL option (so with the example just given files be‐
ginning with `_' in the current directory would still be completed).

CORRECT_IGNORE_FILE
If set, is treated as a pattern during spelling correction of file names. Any file
name that matches the pattern is never offered as a correction. For example, if the
value is `.*' then dot file names will never be offered as spelling corrections. This
is useful with the CORRECT_ALL option.

DIRSTACKSIZE
The maximum size of the directory stack, by default there is no limit. If the stack
gets larger than this, it will be truncated automatically. This is useful with the
AUTO_PUSHD option.

ENV If the ENV environment variable is set when zsh is invoked as sh or ksh, $ENV is
sourced after the profile scripts. The value of ENV is subjected to parameter expan‐
sion, command substitution, and arithmetic expansion before being interpreted as a
pathname. Note that ENV is not used unless the shell is interactive and zsh is emu‐
lating sh or ksh.

FCEDIT The default editor for the fc builtin. If FCEDIT is not set, the parameter EDITOR is
used; if that is not set either, a builtin default, usually vi, is used.

fignore <S> <Z> (FIGNORE <S>)
An array (colon separated list) containing the suffixes of files to be ignored during
filename completion. However, if completion only generates files with suffixes in
this list, then these files are completed anyway.

fpath <S> <Z> (FPATH <S>)
An array (colon separated list) of directories specifying the search path for function
definitions. This path is searched when a function with the -u attribute is refer‐
enced. If an executable file is found, then it is read and executed in the current
environment.

histchars <S>
Three characters used by the shell's history and lexical analysis mechanism. The
first character signals the start of a history expansion (default `!'). The second
character signals the start of a quick history substitution (default `^'). The third
character is the comment character (default `#').

The characters must be in the ASCII character set; any attempt to set histchars to
characters with a locale-dependent meaning will be rejected with an error message.

HISTCHARS <S> <Z>
Same as histchars. (Deprecated.)

HISTFILE
The file to save the history in when an interactive shell exits. If unset, the his‐
tory is not saved.

HISTORY_IGNORE
If set, is treated as a pattern at the time history files are written. Any potential
history entry that matches the pattern is skipped. For example, if the value is `fc
*' then commands that invoke the interactive history editor are never written to the
history file.

Note that HISTORY_IGNORE defines a single pattern: to specify alternatives use the
`(first|second|...)' syntax.

Compare the HIST_NO_STORE option or the zshaddhistory hook, either of which would pre‐
vent such commands from being added to the interactive history at all. If you wish to
use HISTORY_IGNORE to stop history being added in the first place, you can define the
following hook:

zshaddhistory() {
emulate -L zsh
## uncomment if HISTORY_IGNORE
## should use EXTENDED_GLOB syntax
# setopt extendedglob
[[ $1 != ${~HISTORY_IGNORE} ]]
}

HISTSIZE <S>
The maximum number of events stored in the internal history list. If you use the
HIST_EXPIRE_DUPS_FIRST option, setting this value larger than the SAVEHIST size will
give you the difference as a cushion for saving duplicated history events.

If this is made local, it is not implicitly set to 0, but may be explicitly set lo‐
cally.

HOME <S>
The default argument for the cd command. This is not set automatically by the shell
in sh, ksh or csh emulation, but it is typically present in the environment anyway,
and if it becomes set it has its usual special behaviour.

IFS <S>
Internal field separators (by default space, tab, newline and NUL), that are used to
separate words which result from command or parameter expansion and words read by the
read builtin. Any characters from the set space, tab and newline that appear in the
IFS are called IFS white space. One or more IFS white space characters or one non-IFS
white space character together with any adjacent IFS white space character delimit a
field. If an IFS white space character appears twice consecutively in the IFS, this
character is treated as if it were not an IFS white space character.

If the parameter is unset, the default is used. Note this has a different effect from
setting the parameter to an empty string.

KEYBOARD_HACK
This variable defines a character to be removed from the end of the command line be‐
fore interpreting it (interactive shells only). It is intended to fix the problem with
keys placed annoyingly close to return and replaces the SUNKEYBOARDHACK option which
did this for backquotes only. Should the chosen character be one of singlequote, dou‐
blequote or backquote, there must also be an odd number of them on the command line
for the last one to be removed.

For backward compatibility, if the SUNKEYBOARDHACK option is explicitly set, the value
of KEYBOARD_HACK reverts to backquote. If the option is explicitly unset, this vari‐
able is set to empty.

KEYTIMEOUT
The time the shell waits, in hundredths of seconds, for another key to be pressed when
reading bound multi-character sequences.

LANG <S>
This variable determines the locale category for any category not specifically se‐
lected via a variable starting with `LC_'.

LC_ALL <S>
This variable overrides the value of the `LANG' variable and the value of any of the
other variables starting with `LC_'.

LC_COLLATE <S>
This variable determines the locale category for character collation information
within ranges in glob brackets and for sorting.

LC_CTYPE <S>
This variable determines the locale category for character handling functions. If the
MULTIBYTE option is in effect this variable or LANG should contain a value that re‐
flects the character set in use, even if it is a single-byte character set, unless
only the 7-bit subset (ASCII) is used. For example, if the character set is
ISO-8859-1, a suitable value might be en_US.iso88591 (certain Linux distributions) or
en_US.ISO8859-1 (MacOS).

LC_MESSAGES <S>
This variable determines the language in which messages should be written. Note that
zsh does not use message catalogs.

LC_NUMERIC <S>
This variable affects the decimal point character and thousands separator character
for the formatted input/output functions and string conversion functions. Note that
zsh ignores this setting when parsing floating point mathematical expressions.

LC_TIME <S>
This variable determines the locale category for date and time formatting in prompt
escape sequences.

LINES <S>
The number of lines for this terminal session. Used for printing select lists and for
the line editor.

LISTMAX
In the line editor, the number of matches to list without asking first. If the value
is negative, the list will be shown if it spans at most as many lines as given by the
absolute value. If set to zero, the shell asks only if the top of the listing would
scroll off the screen.

MAIL If this parameter is set and mailpath is not set, the shell looks for mail in the
specified file.

MAILCHECK
The interval in seconds between checks for new mail.

mailpath <S> <Z> (MAILPATH <S>)
An array (colon-separated list) of filenames to check for new mail. Each filename can
be followed by a `?' and a message that will be printed. The message will undergo pa‐
rameter expansion, command substitution and arithmetic expansion with the variable $_
defined as the name of the file that has changed. The default message is `You have
new mail'. If an element is a directory instead of a file the shell will recursively
check every file in every subdirectory of the element.

manpath <S> <Z> (MANPATH <S> <Z>)
An array (colon-separated list) whose value is not used by the shell. The manpath ar‐
ray can be useful, however, since setting it also sets MANPATH, and vice versa.

match
mbegin
mend Arrays set by the shell when the b globbing flag is used in pattern matches. See the
subsection Globbing flags in the documentation for Filename Generation in zshexpn(1).

MATCH
MBEGIN
MEND Set by the shell when the m globbing flag is used in pattern matches. See the subsec‐
tion Globbing flags in the documentation for Filename Generation in zshexpn(1).

module_path <S> <Z> (MODULE_PATH <S>)
An array (colon-separated list) of directories that zmodload searches for dynamically
loadable modules. This is initialized to a standard pathname, usually `/usr/lo‐
cal/lib/zsh/$ZSH_VERSION'. (The `/usr/local/lib' part varies from installation to in‐
stallation.) For security reasons, any value set in the environment when the shell is
started will be ignored.

These parameters only exist if the installation supports dynamic module loading.

NULLCMD <S>
The command name to assume if a redirection is specified with no command. Defaults to
cat. For sh/ksh behavior, change this to :. For csh-like behavior, unset this para‐
meter; the shell will print an error message if null commands are entered.

path <S> <Z> (PATH <S>)
An array (colon-separated list) of directories to search for commands. When this pa‐
rameter is set, each directory is scanned and all files found are put in a hash table.

POSTEDIT <S>
This string is output whenever the line editor exits. It usually contains termcap
strings to reset the terminal.

PROMPT <S> <Z>
PROMPT2 <S> <Z>
PROMPT3 <S> <Z>
PROMPT4 <S> <Z>
Same as PS1, PS2, PS3 and PS4, respectively.

prompt <S> <Z>
Same as PS1.

PROMPT_EOL_MARK
When the PROMPT_CR and PROMPT_SP options are set, the PROMPT_EOL_MARK parameter can be
used to customize how the end of partial lines are shown. This parameter undergoes
prompt expansion, with the PROMPT_PERCENT option set. If not set, the default behav‐
ior is equivalent to the value `%B%S%#%s%b'.

PS1 <S>
The primary prompt string, printed before a command is read. It undergoes a special
form of expansion before being displayed; see EXPANSION OF PROMPT SEQUENCES in zsh‐
misc(1). The default is `%m%# '.

PS2 <S>
The secondary prompt, printed when the shell needs more information to complete a com‐
mand. It is expanded in the same way as PS1. The default is `%_> ', which displays
any shell constructs or quotation marks which are currently being processed.

PS3 <S>
Selection prompt used within a select loop. It is expanded in the same way as PS1.
The default is `?# '.

PS4 <S>
The execution trace prompt. Default is `+%N:%i> ', which displays the name of the
current shell structure and the line number within it. In sh or ksh emulation, the
default is `+ '.

psvar <S> <Z> (PSVAR <S>)
An array (colon-separated list) whose elements can be used in PROMPT strings. Setting
psvar also sets PSVAR, and vice versa.

READNULLCMD <S>
The command name to assume if a single input redirection is specified with no command.
Defaults to more.

REPORTMEMORY
If nonnegative, commands whose maximum resident set size (roughly speaking, main mem‐
ory usage) in kilobytes is greater than this value have timing statistics reported.
The format used to output statistics is the value of the TIMEFMT parameter, which is
the same as for the REPORTTIME variable and the time builtin; note that by default
this does not output memory usage. Appending " max RSS %M" to the value of TIMEFMT
causes it to output the value that triggered the report. If REPORTTIME is also in
use, at most a single report is printed for both triggers. This feature requires the
getrusage() system call, commonly supported by modern Unix-like systems.

REPORTTIME
If nonnegative, commands whose combined user and system execution times (measured in
seconds) are greater than this value have timing statistics printed for them. Output
is suppressed for commands executed within the line editor, including completion; com‐
mands explicitly marked with the time keyword still cause the summary to be printed in
this case.

REPLY This parameter is reserved by convention to pass string values between shell scripts
and shell builtins in situations where a function call or redirection are impossible
or undesirable. The read builtin and the select complex command may set REPLY, and
filename generation both sets and examines its value when evaluating certain expres‐
sions. Some modules also employ REPLY for similar purposes.

reply As REPLY, but for array values rather than strings.

RPROMPT <S>
RPS1 <S>
This prompt is displayed on the right-hand side of the screen when the primary prompt
is being displayed on the left. This does not work if the SINGLE_LINE_ZLE option is
set. It is expanded in the same way as PS1.

RPROMPT2 <S>
RPS2 <S>
This prompt is displayed on the right-hand side of the screen when the secondary
prompt is being displayed on the left. This does not work if the SINGLE_LINE_ZLE op‐
tion is set. It is expanded in the same way as PS2.

SAVEHIST
The maximum number of history events to save in the history file.

If this is made local, it is not implicitly set to 0, but may be explicitly set lo‐
cally.

SPROMPT <S>
The prompt used for spelling correction. The sequence `%R' expands to the string
which presumably needs spelling correction, and `%r' expands to the proposed correc‐
tion. All other prompt escapes are also allowed.

The actions available at the prompt are [nyae]:
n (`no') (default)
Discard the correction and run the command.
y (`yes')
Make the correction and run the command.
a (`abort')
Discard the entire command line without running it.
e (`edit')
Resume editing the command line.

STTY If this parameter is set in a command's environment, the shell runs the stty command
with the value of this parameter as arguments in order to set up the terminal before
executing the command. The modes apply only to the command, and are reset when it fin‐
ishes or is suspended. If the command is suspended and continued later with the fg or
wait builtins it will see the modes specified by STTY, as if it were not suspended.
This (intentionally) does not apply if the command is continued via `kill -CONT'.
STTY is ignored if the command is run in the background, or if it is in the environ‐
ment of the shell but not explicitly assigned to in the input line. This avoids run‐
ning stty at every external command by accidentally exporting it. Also note that STTY
should not be used for window size specifications; these will not be local to the com‐
mand.

If the parameter is set and empty, all of the above applies except that stty is not
run. This can be useful as a way to freeze the tty around a single command, blocking
its changes to tty settings, similar to the ttyctl builtin.

TERM <S>
The type of terminal in use. This is used when looking up termcap sequences. An as‐
signment to TERM causes zsh to re-initialize the terminal, even if the value does not
change (e.g., `TERM=$TERM'). It is necessary to make such an assignment upon any
change to the terminal definition database or terminal type in order for the new set‐
tings to take effect.

TERMINFO <S>
A reference to your terminfo database, used by the `terminfo' library when the system
has it; see terminfo(5). If set, this causes the shell to reinitialise the terminal,
making the workaround `TERM=$TERM' unnecessary.

TERMINFO_DIRS <S>
A colon-seprarated list of terminfo databases, used by the `terminfo' library when the
system has it; see terminfo(5). This variable is only used by certain terminal li‐
braries, in particular ncurses; see terminfo(5) to check support on your system. If
set, this causes the shell to reinitialise the terminal, making the workaround
`TERM=$TERM' unnecessary. Note that unlike other colon-separated arrays this is not
tied to a zsh array.

TIMEFMT
The format of process time reports with the time keyword. The default is `%J %U user
%S system %P cpu %*E total'. Recognizes the following escape sequences, although not
all may be available on all systems, and some that are available may not be useful:

%% A `%'.
%U CPU seconds spent in user mode.
%S CPU seconds spent in kernel mode.
%E Elapsed time in seconds.
%P The CPU percentage, computed as 100*(%U+%S)/%E.
%W Number of times the process was swapped.
%X The average amount in (shared) text space used in kilobytes.
%D The average amount in (unshared) data/stack space used in kilobytes.
%K The total space used (%X+%D) in kilobytes.
%M The maximum memory the process had in use at any time in kilobytes.
%F The number of major page faults (page needed to be brought from disk).
%R The number of minor page faults.
%I The number of input operations.
%O The number of output operations.
%r The number of socket messages received.
%s The number of socket messages sent.
%k The number of signals received.
%w Number of voluntary context switches (waits).
%c Number of involuntary context switches.
%J The name of this job.

A star may be inserted between the percent sign and flags printing time (e.g., `%*E');
this causes the time to be printed in `hh:mm:ss.ttt' format (hours and minutes are
only printed if they are not zero). Alternatively, `m' or `u' may be used (e.g.,
`%mE') to produce time output in milliseconds or microseconds, respectively.

TMOUT If this parameter is nonzero, the shell will receive an ALRM signal if a command is
not entered within the specified number of seconds after issuing a prompt. If there is
a trap on SIGALRM, it will be executed and a new alarm is scheduled using the value of
the TMOUT parameter after executing the trap. If no trap is set, and the idle time of
the terminal is not less than the value of the TMOUT parameter, zsh terminates. Oth‐
erwise a new alarm is scheduled to TMOUT seconds after the last keypress.

TMPPREFIX
A pathname prefix which the shell will use for all temporary files. Note that this
should include an initial part for the file name as well as any directory names. The
default is `/tmp/zsh'.

TMPSUFFIX
A filename suffix which the shell will use for temporary files created by process sub‐
stitutions (e.g., `=(list)'). Note that the value should include a leading dot `.' if
intended to be interpreted as a file extension. The default is not to append any suf‐
fix, thus this parameter should be assigned only when needed and then unset again.

WORDCHARS <S>
A list of non-alphanumeric characters considered part of a word by the line editor.

ZBEEP If set, this gives a string of characters, which can use all the same codes as the
bindkey command as described in the zsh/zle module entry in zshmodules(1), that will
be output to the terminal instead of beeping. This may have a visible instead of an
audible effect; for example, the string `\e[?5h\e[?5l' on a vt100 or xterm will have
the effect of flashing reverse video on and off (if you usually use reverse video, you
should use the string `\e[?5l\e[?5h' instead). This takes precedence over the NOBEEP
option.

ZDOTDIR
The directory to search for shell startup files (.zshrc, etc), if not $HOME.

zle_bracketed_paste
Many terminal emulators have a feature that allows applications to identify when text
is pasted into the terminal rather than being typed normally. For ZLE, this means that
special characters such as tabs and newlines can be inserted instead of invoking edi‐
tor commands. Furthermore, pasted text forms a single undo event and if the region is
active, pasted text will replace the region.

This two-element array contains the terminal escape sequences for enabling and dis‐
abling the feature. These escape sequences are used to enable bracketed paste when ZLE
is active and disable it at other times. Unsetting the parameter has the effect of
ensuring that bracketed paste remains disabled.

zle_highlight
An array describing contexts in which ZLE should highlight the input text. See Char‐
acter Highlighting in zshzle(1).

ZLE_LINE_ABORTED
This parameter is set by the line editor when an error occurs. It contains the line
that was being edited at the point of the error. `print -zr -- $ZLE_LINE_ABORTED' can
be used to recover the line. Only the most recent line of this kind is remembered.

ZLE_REMOVE_SUFFIX_CHARS
ZLE_SPACE_SUFFIX_CHARS
These parameters are used by the line editor. In certain circumstances suffixes (typ‐
ically space or slash) added by the completion system will be removed automatically,
either because the next editing command was not an insertable character, or because
the character was marked as requiring the suffix to be removed.

These variables can contain the sets of characters that will cause the suffix to be
removed. If ZLE_REMOVE_SUFFIX_CHARS is set, those characters will cause the suffix to
be removed; if ZLE_SPACE_SUFFIX_CHARS is set, those characters will cause the suffix
to be removed and replaced by a space.

If ZLE_REMOVE_SUFFIX_CHARS is not set, the default behaviour is equivalent to:

ZLE_REMOVE_SUFFIX_CHARS=$' \t\n;&|'

If ZLE_REMOVE_SUFFIX_CHARS is set but is empty, no characters have this behaviour.
ZLE_SPACE_SUFFIX_CHARS takes precedence, so that the following:

ZLE_SPACE_SUFFIX_CHARS=$'&|'

causes the characters `&' and `|' to remove the suffix but to replace it with a space.

To illustrate the difference, suppose that the option AUTO_REMOVE_SLASH is in effect
and the directory DIR has just been completed, with an appended /, following which the
user types `&'. The default result is `DIR&'. With ZLE_REMOVE_SUFFIX_CHARS set but
without including `&' the result is `DIR/&'. With ZLE_SPACE_SUFFIX_CHARS set to in‐
clude `&' the result is `DIR &'.

Note that certain completions may provide their own suffix removal or replacement be‐
haviour which overrides the values described here. See the completion system documen‐
tation in zshcompsys(1).

ZLE_RPROMPT_INDENT <S>
If set, used to give the indentation between the right hand side of the right prompt
in the line editor as given by RPS1 or RPROMPT and the right hand side of the screen.
If not set, the value 1 is used.

Typically this will be used to set the value to 0 so that the prompt appears flush
with the right hand side of the screen. This is not the default as many terminals do
not handle this correctly, in particular when the prompt appears at the extreme bottom
right of the screen. Recent virtual terminals are more likely to handle this case
correctly. Some experimentation is necessary.

zsh 5.9 May 14, 2022 ZSHPARAM(1)

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