ZSHPARAM(1) User Commands 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 referred to as a variable.

The attributes of a parameter determine the type of its value, often
referred to as the parameter 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. Exported parameters are
called environment variables. The shell also imports environment
variables 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 interfere 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 retained.

To declare the type of a parameter, or to assign a string or numeric
value to a scalar parameter, 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 parameter 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, assigning 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 array.

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 expression that may be used when directly subscripting a
variable name, described in the section `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 differs 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 generation, 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 consecutive 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 alternating 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, deleting 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 append to the existing
value at that key. Expansion is performed identically to the
corresponding 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 numbered 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 subscript that evaluates to zero return an empty
string, while an attempt to write such an element 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 expansion 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. `"$foo[*]"' evaluates to `"$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 Parameter
Expansion Flags in zshexpn(1) for complete details. When an array
parameter is referenced as `$name' (with no subscript) it evaluates
to `$name[*]', unless the KSH_ARRAYS option 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, inclusive. (Associative arrays are unordered, and
so do not support ranges.) If one of the subscripts evaluates to a
negative number, say -n, then the nth element from the end of the
array 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
matching, and in that case the substring extends from the start of
the match of the first subscript 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 expression 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 followed 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 character, 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 result 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, respectively). 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
parameter 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 inhibit 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 associative 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 indistinguishable 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 interpreted 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 delimiter
character : is arbitrary; see above.

b:expr:
If combined with `r', `R', `i' or `I', makes them begin at the
nth or nth last element, word, or character (if expr evaluates
to n). This flag is ignored when the array 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
substitution 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 reverse subscripting (the `r', `R', `i', etc.
flags), but it may also affect parameter substitutions 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 zshmisc(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 subscript expression unless they are preceded by
a backslash (`\'). Therefore, within a subscript expression (and
unlike true double-quoting) the sequence `\[' becomes `[', and
similarly `\]' becomes `]'. This applies even in cases where a
backslash is not normally required; 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 expression 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,
because of the standard shell quoting rules, any double-quotes that
appear must occur in balanced pairs unless preceded by a backslash.
This makes it more difficult to write a subscript 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 subscript 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 associative 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 appearing in the subscript expression are
first expanded and then the complete expression is interpreted 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
necessary 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, parentheses, 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 parameters (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 parameter, 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 entire
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 `Functions'. The
parameter n, where n is a number, is the nth positional parameter.
The parameter `$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 unexpected 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 emulation mode.

The parameters `!', `#', `*', `-', `?', `@', `$', `ARGC', `HISTCMD',
`LINENO', `PPID', `status', `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 applies 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 interpreted 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 substitute 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
everywhere, 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 returns.

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 environment 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 locally.

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 locally.

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 functions. 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 typically 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 (assuming
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 locally.

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 original 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 initialized 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; subshells 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 invocations.

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 using 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 numbering 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 interrupt 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 sufficient
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 locally.

USERNAME <S>
The username corresponding to the real user ID of the shell
process. If you have sufficient 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 operations 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 functions have the context shfunc. As
traps are asynchronous they may have a different
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 module.

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
development 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 compensation 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 dialing 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 completion functions
(which, by convention, have names beginning with `_') will
never be offered 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
beginning 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 expansion, 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 emulating 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 referenced. 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 history 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 prevent 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 locally.

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 before 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, doublequote 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 variable
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 selected 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 reflects 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 parameter
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 array 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 subsection 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/local/lib/zsh/$ZSH_VERSION'. (The `/usr/local/lib' part
varies from installation to installation.) 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 parameter; 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 parameter 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 behavior 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 zshmisc(1).
The default is `%m%# '.

PS2 <S>
The secondary prompt, printed when the shell needs more
information to complete a command. 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 memory 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; commands 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 expressions. 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 option 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 locally.

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 correction. 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 finishes 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 environment of the
shell but not explicitly assigned to in the input line. This
avoids running 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
command.

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 assignment 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 settings 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 libraries, 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. Otherwise 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 substitutions (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 suffix, 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 editor 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 disabling 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 Character 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 (typically 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 include
`&' the result is `DIR &'.

Note that certain completions may provide their own suffix
removal or replacement behaviour which overrides the values
described here. See the completion system documentation 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)