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diff --git a/Doc/zshparam.1 b/Doc/zshparam.1 new file mode 100644 index 000000000..d797ea96e --- /dev/null +++ b/Doc/zshparam.1 @@ -0,0 +1,1928 @@ +.TH "ZSHPARAM" "1" "February 14, 2020" "zsh 5\&.8" +.SH "NAME" +zshparam \- zsh parameters +.\" Yodl file: Zsh/params.yo +.SH "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 +`\fB*\fP\&', `\fB@\fP', `\fB#\fP', `\fB?\fP', `\fB\-\fP', `\fB$\fP', or `\fB!\fP'\&. +A parameter whose name begins with an alphanumeric or underscore is also +referred to as a \fIvariable\fP\&. +.PP +The attributes of a parameter determine the \fItype\fP 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 \fIscalar\fP (a string, an integer, or a floating +point number), an array (indexed numerically), or an \fIassociative\fP +array (an unordered set of name\-value pairs, indexed by name, also +referred to as a \fIhash\fP)\&. +.PP +Named scalar parameters may have the \fIexported\fP, \fB\-x\fP, 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 +\fIenvironment variables\fP\&. The shell also \fIimports\fP 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\&. +.PP +Parameters may also be \fIspecial\fP, 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\&. +.PP +To declare the type of a parameter, or to assign a string or numeric value +to a scalar parameter, use the \fBtypeset\fP builtin\&. +.PP +The value of a scalar parameter may also be assigned by writing: + +.RS +.nf +\fIname\fP\fB=\fP\fIvalue\fP +.fi +.RE +.PP +In scalar assignment, \fIvalue\fP is expanded as a single string, in +which the elements of arrays are joined together; filename expansion is +not performed unless the option \fBGLOB_ASSIGN\fP is set\&. +.PP +When the integer attribute, \fB\-i\fP, or a floating point attribute, \fB\-E\fP +or \fB\-F\fP, is set for \fIname\fP, the \fIvalue\fP is subject to arithmetic +evaluation\&. Furthermore, by replacing `\fB=\fP\&' with `\fB+=\fP', a parameter +can be incremented or appended to\&. See the section `Array Parameters\&' and +\fIArithmetic Evaluation\fP (in \fIzshmisc\fP(1)) +for additional forms of assignment\&. +.PP +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 \fBGLOB_ASSIGN\fP assigning a +pattern to a variable may change its type to an array\&. +.PP +To reference the value of a parameter, write `\fB$\fP\fIname\fP\&' or +`\fB${\fP\fIname\fP\fB}\fP\&'\&. See +\fIParameter Expansion\fP in \fIzshexpn\fP(1) +for complete details\&. That section also explains the effect +of the difference between scalar and array assignment on parameter +expansion\&. +.SH "ARRAY PARAMETERS" +To assign an array value, write one of: + +.RS +.nf +\fBset \-A\fP \fIname\fP \fIvalue\fP \&.\&.\&. +.fi +.RE +.RS +.nf +\fIname\fP\fB=(\fP\fIvalue\fP \&.\&.\&.\fB)\fP +.fi +.RE +.RS +.nf +\fIname\fP\fB=(\fP\fB[\fP\fIkey\fP\fB]=\fP\fIvalue\fP \&.\&.\&.\fB)\fP +.fi +.RE +.PP +If no parameter \fIname\fP exists, an ordinary array parameter is created\&. +If the parameter \fIname\fP exists and is a scalar, it is replaced by a new +array\&. +.PP +In the third form, \fIkey\fP 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 \fIvalue\fP\&. 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: \fB[\fP and \fB]=\fP must +not be quoted, and \fIkey\fP may not consist of the unquoted string +\fB]=\fP, 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\&. +.PP +The syntaxes with and without the explicit key may be mixed\&. An implicit +\fIkey\fP 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\&. +.PP +For example, assuming the option \fBKSH_ARRAYS\fP is not set, the following: +.PP +.RS +.nf +\fBarray=(one [3]=three four)\fP +.fi +.RE +.PP +causes the array variable \fBarray\fP to contain four elements \fBone\fP, +an empty string, \fBthree\fP and \fBfour\fP, in that order\&. +.PP +In the forms where only \fIvalue\fP is specified, full command +line expansion is performed\&. +.PP +In the \fB[\fP\fIkey\fP\fB]=\fP\fIvalue\fP form, +both \fIkey\fP and \fIvalue\fP 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 +\fB(e)\fP as described in +\fIzshexpn\fP(1)\&. +Nested parentheses may surround \fIvalue\fP 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: + +.RS +.nf +\fIname\fP\fB=(\fP\fB[a\-z]\&'='*)\fP +.fi +.RE +.PP +To append to an array without changing the existing values, use +one of the following: + +.RS +.nf +\fIname\fP\fB+=(\fP\fIvalue\fP \&.\&.\&.\fB)\fP +.fi +.RE +.RS +.nf +\fIname\fP\fB+=(\fP\fB[\fP\fIkey\fP\fB]=\fP\fIvalue\fP \&.\&.\&.\fB)\fP +.fi +.RE +.PP +In the second form \fIkey\fP may specify an existing index as well as an +index off the end of the old array; any existing value is overwritten by +\fIvalue\fP\&. Also, it is possible to use \fB[\fP\fIkey\fP\fB]+=\fP\fIvalue\fP +to append to the existing value at that index\&. +.PP +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 \fIvalue\fPs\&. Any consecutive sequence of such +characters has the same effect\&. +.PP +Ordinary array parameters may also be explicitly declared with: + +.RS +.nf +\fBtypeset \-a\fP \fIname\fP +.fi +.RE +.PP +Associative arrays \fImust\fP be declared before assignment, by using: + +.RS +.nf +\fBtypeset \-A\fP \fIname\fP +.fi +.RE +.PP +When \fIname\fP refers to an associative array, the list in an assignment +is interpreted as alternating keys and values: + +.RS +.nf +\fBset \-A\fP \fIname\fP \fIkey\fP \fIvalue\fP \&.\&.\&. +.fi +.RE +.RS +.nf +\fIname\fP\fB=(\fP\fIkey\fP \fIvalue\fP \&.\&.\&.\fB)\fP +.fi +.RE +.RS +.nf +\fIname\fP\fB=(\fP\fB[\fP\fIkey\fP\fB]=\fP\fIvalue\fP \&.\&.\&.\fB)\fP +.fi +.RE +.PP +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\&. +.PP +Every \fIkey\fP must have a \fIvalue\fP 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: + +.RS +.nf +\fIname\fP\fB+=(\fP\fIkey\fP \fIvalue\fP \&.\&.\&.\fB)\fP +.fi +.RE +.RS +.nf +\fIname\fP\fB+=(\fP\fB[\fP\fIkey\fP\fB]=\fP\fIvalue\fP \&.\&.\&.\fB)\fP +.fi +.RE +.PP +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 \fB[\fP\fIkey\fP\fB]+=\fP\fIvalue\fP to +append to the existing value at that key\&. Expansion is performed +identically to the corresponding forms for normal arrays, as +described above\&. +.PP +To create an empty array (including associative arrays), use one of: + +.RS +.nf +\fBset \-A\fP \fIname\fP +.fi +.RE +.RS +.nf +\fIname\fP\fB=()\fP +.fi +.RE +.PP +.SS "Array Subscripts" +Individual elements of an array may be selected using a subscript\&. A +subscript of the form `\fB[\fP\fIexp\fP\fB]\fP\&' selects the single element +\fIexp\fP, where \fIexp\fP is an arithmetic expression which will be subject +to arithmetic expansion as if it were surrounded by +`\fB$((\fP\&.\&.\&.\fB))\fP\&'\&. The elements are numbered +beginning with 1, unless the \fBKSH_ARRAYS\fP option is set in which case +they are numbered from zero\&. +.PP +Subscripts may be used inside braces used to delimit a parameter name, thus +`\fB${foo[2]}\fP\&' is equivalent to `\fB$foo[2]\fP'\&. If the \fBKSH_ARRAYS\fP +option is set, the braced form is the only one that works, as bracketed +expressions otherwise are not treated as subscripts\&. +.PP +If the \fBKSH_ARRAYS\fP 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 \fBKSH_ZERO_SUBSCRIPT\fP +option can be set to cause subscript values 0 and 1 to be equivalent; see +the description of the option in \fIzshoptions\fP(1)\&. +.PP +The same subscripting syntax is used for associative arrays, except that +no arithmetic expansion is applied to \fIexp\fP\&. However, the parsing +rules for arithmetic expressions still apply, which affects the way that +certain special characters must be protected from interpretation\&. See +\fISubscript Parsing\fP below for details\&. +.PP +A subscript of the form `\fB[*]\fP\&' or `\fB[@]\fP' evaluates to all elements +of an array; there is no difference between the two except when they +appear within double quotes\&. +`\fB"$foo[*]"\fP\&' evaluates to `\fB"$foo[1] $foo[2] \fP\&.\&.\&.\fB"\fP', whereas +`\fB"$foo[@]"\fP\&' evaluates to `\fB"$foo[1]" "$foo[2]" \fP\&.\&.\&.'\&. For +associative arrays, `\fB[*]\fP\&' or `\fB[@]\fP' evaluate to all the values, +in no particular order\&. Note that this does not substitute +the keys; see the documentation for the `\fBk\fP\&' flag under +\fIParameter Expansion Flags\fP in \fIzshexpn\fP(1) +for complete details\&. +When an array parameter is referenced as `\fB$\fP\fIname\fP\&' (with no +subscript) it evaluates to `\fB$\fP\fIname\fP\fB[*]\fP\&', unless the \fBKSH_ARRAYS\fP +option is set in which case it evaluates to `\fB${\fP\fIname\fP\fB[0]}\fP\&' (for +an associative array, this means the value of the key `\fB0\fP\&', which may +not exist even if there are values for other keys)\&. +.PP +A subscript of the form `\fB[\fP\fIexp1\fP\fB,\fP\fIexp2\fP\fB]\fP\&' +selects all elements in the range \fIexp1\fP to \fIexp2\fP, +inclusive\&. (Associative arrays are unordered, and so do not support +ranges\&.) If one of the subscripts evaluates to a negative number, +say \fB\-\fP\fIn\fP, then the \fIn\fPth element from the end +of the array is used\&. Thus `\fB$foo[\-3]\fP\&' is the third element +from the end of the array \fBfoo\fP, and +`\fB$foo[1,\-1]\fP\&' is the same as `\fB$foo[*]\fP'\&. +.PP +Subscripting may also be performed on non\-array values, in which +case the subscripts specify a substring to be extracted\&. +For example, if \fBFOO\fP is set to `\fBfoobar\fP\&', then +`\fBecho $FOO[2,5]\fP\&' prints `\fBooba\fP'\&. 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, +.PP +.RS +.nf +\fBstring="abcdefghijklm" +print ${string[(r)d?,(r)h?]}\fP +.fi +.RE +.PP +prints `\fBdefghi\fP\&'\&. 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)\&. +.PP +Note that in substring operations the second subscript is handled +differently by the \fBr\fP and \fBR\fP subscript flags: the former takes the +shortest match as the length and the latter the longest match\&. Hence +in the former case a \fB*\fP 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\&. +.PP +.SS "Array Element Assignment" +.PP +A subscript may be used on the left side of an assignment like so: + +.RS +.nf +\fIname\fP\fB[\fP\fIexp\fP\fB]=\fP\fIvalue\fP +.fi +.RE +.PP +In this form of assignment the element or range specified by \fIexp\fP +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\&.) +.PP +This syntax also works as an argument to the \fBtypeset\fP command: + +.RS +.nf +\fBtypeset\fP \fB"\fP\fIname\fP\fB[\fP\fIexp\fP\fB]"=\fP\fIvalue\fP +.fi +.RE +.PP +The \fIvalue\fP may \fInot\fP be a parenthesized list in this case; only +single\-element assignments may be made with \fBtypeset\fP\&. Note that quotes +are necessary in this case to prevent the brackets from being interpreted +as filename generation operators\&. The \fBnoglob\fP precommand modifier +could be used instead\&. +.PP +To delete an element of an ordinary array, assign `\fB()\fP\&' to +that element\&. To delete an element of an associative array, use the +\fBunset\fP command: + +.RS +.nf +\fBunset\fP \fB"\fP\fIname\fP\fB[\fP\fIexp\fP\fB]"\fP +.fi +.RE +.PP +.SS "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 +`\fIname\fP\fB[(\fP\fIflags\fP\fB)\fP\fIexp\fP\fB]\fP\&'\&. +.PP +The flags \fBs\fP, \fBn\fP and \fBb\fP take an argument; the delimiter +is shown below as `\fB:\fP\&', but any character, or the matching pairs +`\fB(\fP\&.\&.\&.\fB)\fP\&', `\fB{\fP\&.\&.\&.\fB}\fP', `\fB[\fP\&.\&.\&.\fB]\fP', or +`\fB<\fP\&.\&.\&.\fB>\fP\&', may be used, but note that `\fB<\fP\&.\&.\&.\fB>\fP' 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\&. +.PP +The flags currently understood are: +.PP +.PD 0 +.TP +.PD +\fBw\fP +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 \fBi\fP or \fBI\fP 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\&. +.TP +\fBs:\fP\fIstring\fP\fB:\fP +This gives the \fIstring\fP that separates words (for use with the +\fBw\fP flag)\&. The delimiter character \fB:\fP is arbitrary; see above\&. +.TP +\fBp\fP +Recognize the same escape sequences as the \fBprint\fP builtin in +the string argument of a subsequent `\fBs\fP\&' flag\&. +.TP +\fBf\fP +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 `\fBpws:\en:\fP\&'\&. +.TP +\fBr\fP +Reverse subscripting: if this flag is given, the \fIexp\fP 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 `\fBw\fP\&' flag is given, respectively)\&. The subscript used +is the number of the matching element, so that pairs of subscripts such as +`\fB$foo[(r)??,3]\fP\&' and `\fB$foo[(r)??,(r)f*]\fP' are +possible if the parameter is not an associative array\&. If the +parameter is an associative array, only the value part of each pair is +compared to the pattern, and the result is that value\&. +.RS +.PP +If a search through an ordinary array failed, the search sets the +subscript to one past the end of the array, and hence +\fB${array[(r)\fP\fIpattern\fP\fB]}\fP will substitute the empty string\&. Thus the +success of a search can be tested by using the \fB(i)\fP flag, for +example (assuming the option \fBKSH_ARRAYS\fP is not in effect): +.PP +.RS +.nf +\fB[[ ${array[(i)pattern]} \-le ${#array} ]]\fP +.fi +.RE +.PP +If \fBKSH_ARRAYS\fP is in effect, the \fB\-le\fP should be replaced by \fB\-lt\fP\&. +.RE +.TP +\fBR\fP +Like `\fBr\fP\&', 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 \fBKSH_ARRAYS\fP or +\fBKSH_ZERO_SUBSCRIPT\fP is in effect\&. +.RS +.PP +Note that in subscripts with both `\fBr\fP\&' and `\fBR\fP' pattern characters +are active even if they were substituted for a parameter (regardless of the +setting of \fBGLOB_SUBST\fP which controls this feature in normal pattern +matching)\&. The flag `\fBe\fP\&' 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: +.PP +.RS +.nf +\fBkey2=\&'original key' +print ${array[(Re)$key2]}\fP +.fi +.RE +.RE +.TP +\fBi\fP +Like `\fBr\fP\&', 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 `\fBr\fP\&'\&. 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 `\fBr\fP\&', or the empty string for an +associative array\&. +.TP +\fBI\fP +Like `\fBi\fP\&', 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\&. +.TP +\fBk\fP +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 \fIexp\fP 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 `\fBr\fP\&'\&. +.TP +\fBK\fP +On an associative array this is like `\fBk\fP\&' but returns all values where +\fIexp\fP is matched by the keys\&. On other types of parameters this has +the same effect as `\fBR\fP\&'\&. +.TP +\fBn:\fP\fIexpr\fP\fB:\fP +If combined with `\fBr\fP\&', `\fBR\fP', `\fBi\fP' or `\fBI\fP', makes them give +the \fIn\fPth or \fIn\fPth last match (if \fIexpr\fP evaluates to +\fIn\fP)\&. This flag is ignored when the array is associative\&. +The delimiter character \fB:\fP is arbitrary; see above\&. +.TP +\fBb:\fP\fIexpr\fP\fB:\fP +If combined with `\fBr\fP\&', `\fBR\fP', `\fBi\fP' or `\fBI\fP', makes them begin +at the \fIn\fPth or \fIn\fPth last element, word, or character (if \fIexpr\fP +evaluates to \fIn\fP)\&. This flag is ignored when the array is associative\&. +The delimiter character \fB:\fP is arbitrary; see above\&. +.TP +\fBe\fP +This flag causes any pattern matching that would be performed on the +subscript to use plain string matching instead\&. Hence +`\fB${array[(re)*]}\fP\&' matches only the array element whose value is \fB*\fP\&. +Note that other forms of substitution such as parameter substitution are +not inhibited\&. +.RS +.PP +This flag can also be used to force \fB*\fP or \fB@\fP 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\&. +.RE +.PP +See \fIParameter Expansion Flags\fP (\fIzshexpn\fP(1)) for additional ways to manipulate the results of array subscripting\&. +.PP +.SS "Subscript Parsing" +.PP +This discussion applies mainly to associative array key strings and to +patterns used for reverse subscripting (the `\fBr\fP\&', `\fBR\fP', `\fBi\fP', +etc\&. flags), but it may also affect parameter substitutions that appear +as part of an arithmetic expression in an ordinary subscript\&. +.PP +To avoid subscript parsing limitations in assignments to associative array +elements, use the append syntax: +.PP +.RS +.nf +\fBaa+=(\&'key with "*strange*" characters' 'value string')\fP +.fi +.RE +.PP +The basic rule to remember when writing a subscript expression is that all +text between the opening `\fB[\fP\&' and the closing `\fB]\fP' is interpreted +\fIas if\fP it were in double quotes (see \fIzshmisc\fP(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\&. +.PP +The first difference is that brackets (`\fB[\fP\&' and `\fB]\fP') must appear as +balanced pairs in a subscript expression unless they are preceded by a +backslash (`\fB\e\fP\&')\&. Therefore, within a subscript expression (and unlike +true double\-quoting) the sequence `\fB\e[\fP\&' becomes `\fB[\fP', and similarly +`\fB\e]\fP\&' becomes `\fB]\fP'\&. This applies even in cases where a backslash is +not normally required; for example, the pattern `\fB[^[]\fP\&' (to match any +character other than an open bracket) should be written `\fB[^\e[]\fP\&' in a +reverse\-subscript pattern\&. However, note that `\fB\e[^\e[\e]\fP\&' and even +`\fB\e[^[]\fP\&' mean the \fIsame\fP thing, because backslashes are always +stripped when they appear before brackets! +.PP +The same rule applies to parentheses (`\fB(\fP\&' and `\fB)\fP') and +braces (`\fB{\fP\&' and `\fB}\fP'): 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\&. +.PP +The second difference is that a double\-quote (`\fB"\fP\&') may appear as part +of a subscript expression without being preceded by a backslash, and +therefore that the two characters `\fB\e"\fP\&' remain as two characters in the +subscript (in true double\-quoting, `\fB\e"\fP\&' becomes `\fB"\fP')\&. 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 `\fB\e"\fP\&' (rather than `\fB\e\e\e"\fP') for `\fB"\fP'\&. +.PP +To use an odd number of double quotes as a key in an assignment, use the +\fBtypeset\fP builtin and an enclosing pair of double quotes; to refer to +the value of that key, again use double quotes: +.PP +.RS +.nf +\fBtypeset \-A aa +typeset "aa[one\e"two\e"three\e"quotes]"=QQQ +print "$aa[one\e"two\e"three\e"quotes]"\fP +.fi +.RE +.PP +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\&. +.PP +A further complication arises from a way in which subscript parsing is +\fInot\fP different from double quote parsing\&. As in true double\-quoting, +the sequences `\fB\e*\fP\&', and `\fB\e@\fP' remain as two characters when they +appear in a subscript expression\&. To use a literal `\fB*\fP\&' or `\fB@\fP' as +an associative array key, the `\fBe\fP\&' flag must be used: +.PP +.RS +.nf +\fBtypeset \-A aa +aa[(e)*]=star +print $aa[(e)*]\fP +.fi +.RE +.PP +A last detail must be considered when reverse subscripting is performed\&. +Parameters appearing in the subscript expression are first expanded and +then the complete expression is interpreted as a pattern\&. This has two +effects: first, parameters behave as if \fBGLOB_SUBST\fP were on (and it +cannot be turned off); second, backslashes are interpreted twice, once +when parsing the array subscript and again when parsing the pattern\&. In a +reverse subscript, it\&'s necessary to use \fIfour\fP backslashes to cause a +single backslash to match literally in the pattern\&. For complex patterns, +it is often easiest to assign the desired pattern to a parameter and then +refer to that parameter in the subscript, because then the backslashes, +brackets, parentheses, etc\&., are seen only when the complete expression is +converted to a pattern\&. To match the value of a parameter literally in a +reverse subscript, rather than as a pattern, +use `\fB${(q\fP\fB)\fP\fIname\fP\fB}\fP\&' (see \fIzshexpn\fP(1)) to quote the expanded value\&. +.PP +Note that the `\fBk\fP\&' and `\fBK\fP' flags are reverse subscripting for an +ordinary array, but are \fInot\fP 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\&.) +.PP +One final note, not directly related to subscripting: the numeric names +of positional parameters (described below) are parsed specially, so for example `\fB$2foo\fP\&' is equivalent to +`\fB${2}foo\fP\&'\&. Therefore, to use subscript syntax to extract a substring +from a positional parameter, the expansion must be surrounded by braces; +for example, `\fB${2[3,5]}\fP\&' evaluates to the third through fifth +characters of the second positional parameter, but `\fB$2[3,5]\fP\&' is the +entire second parameter concatenated with the filename generation pattern +`\fB[3,5]\fP\&'\&. +.PP +.SH "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 \fIn\fP, where \fIn\fP is a number, +is the \fIn\fPth positional parameter\&. +The parameter `\fB$0\fP\&' is a special case, see +the section `Parameters Set By The Shell\&'\&. +.PP +The parameters \fB*\fP, \fB@\fP and \fBargv\fP are +arrays containing all the positional parameters; +thus `\fB$argv[\fP\fIn\fP\fB]\fP\&', etc\&., is equivalent to simply `\fB$\fP\fIn\fP'\&. +Note that the options \fBKSH_ARRAYS\fP or \fBKSH_ZERO_SUBSCRIPT\fP apply +to these arrays as well, so with either of those options set, +`\fB${argv[0]}\fP\&' is equivalent to `\fB$1\fP' and so on\&. +.PP +Positional parameters may be changed after the shell or function starts by +using the \fBset\fP builtin, by assigning to the \fBargv\fP array, or by direct +assignment of the form `\fIn\fP\fB=\fP\fIvalue\fP\&' where \fIn\fP is the number of +the positional parameter to be changed\&. This also creates (with empty +values) any of the positions from 1 to \fIn\fP that do not already have +values\&. Note that, because the positional parameters form an array, an +array assignment of the form `\fIn\fP\fB=(\fP\fIvalue\fP \&.\&.\&.\fB)\fP\&' is +allowed, and has the effect of shifting all the values at positions greater +than \fIn\fP by as many positions as necessary to accommodate the new values\&. +.PP +.SH "LOCAL PARAMETERS" +Shell function executions delimit scopes for shell parameters\&. +(Parameters are dynamically scoped\&.) The \fBtypeset\fP builtin, and its +alternative forms \fBdeclare\fP, \fBinteger\fP, \fBlocal\fP and \fBreadonly\fP +(but not \fBexport\fP), can be used to declare a parameter as being local +to the innermost scope\&. +.PP +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 \fBexport\fP, +causes it to be created in the \fIouter\fPmost scope\&. +.PP +Local parameters disappear when their scope ends\&. +\fBunset\fP can be used to delete a parameter while it is still in scope; +any outer parameter of the same name remains hidden\&. +.PP +Special parameters may also be made local; they retain their special +attributes unless either the existing or the newly\-created parameter +has the \fB\-h\fP (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: +.PP +.RS +.nf +\fBtypeset PATH=/new/directory:$PATH\fP +.fi +.RE +.PP +is valid for temporarily allowing the shell or programmes called from it to +find the programs in \fB/new/directory\fP inside a function\&. +.PP +Note that the restriction in older versions of zsh that local parameters +were never exported has been removed\&. +.PP +.SH "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 \fBsh\fP or \fBksh\fP emulation mode\&. +.PP +The following parameters are automatically set by the shell: +.PP +.PD 0 +.TP +.PD +\fB!\fP <S> +The process ID of the last command started in the background with \fB&\fP, +put into the background with the \fBbg\fP builtin, or spawned with \fBcoproc\fP\&. +.TP +\fB#\fP <S> +The number of positional parameters in decimal\&. Note that some confusion +may occur with the syntax \fB$#\fP\fIparam\fP which substitutes the length of +\fIparam\fP\&. Use \fB${#}\fP to resolve ambiguities\&. In particular, the +sequence `\fB$#\-\fP\fI\&.\&.\&.\fP\&' in an arithmetic expression is interpreted as +the length of the parameter \fB\-\fP, q\&.v\&. +.TP +\fBARGC\fP <S> <Z> +Same as \fB#\fP\&. +.TP +\fB$\fP <S> +The process ID of this shell\&. Note that this indicates the original +shell started by invoking \fBzsh\fP; all processes forked from the shells +without executing a new program, such as subshells started by +\fB(\fP\fI\&.\&.\&.\fP\fB)\fP, substitute the same value\&. +.TP +\fB\-\fP <S> +Flags supplied to the shell on invocation or by the \fBset\fP +or \fBsetopt\fP commands\&. +.TP +\fB*\fP <S> +An array containing the positional parameters\&. +.TP +\fBargv\fP <S> <Z> +Same as \fB*\fP\&. Assigning to \fBargv\fP changes the local positional +parameters, but \fBargv\fP is \fInot\fP itself a local parameter\&. +Deleting \fBargv\fP with \fBunset\fP in any function deletes it everywhere, +although only the innermost positional parameter array is deleted (so +\fB*\fP and \fB@\fP in other scopes are not affected)\&. +.TP +\fB@\fP <S> +Same as \fBargv[@]\fP, even when \fBargv\fP is not set\&. +.TP +\fB?\fP <S> +The exit status returned by the last command\&. +.TP +\fB0\fP <S> +The name used to invoke the current shell, or as set by the \fB\-c\fP command +line option upon invocation\&. If the \fBFUNCTION_ARGZERO\fP option is set, +\fB$0\fP 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\&. +.TP +\fBstatus\fP <S> <Z> +Same as \fB?\fP\&. +.TP +\fBpipestatus\fP <S> <Z> +An array containing the exit statuses returned by all commands in the +last pipeline\&. +.TP +\fB_\fP <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\&. +.TP +\fBCPUTYPE\fP +The machine type (microprocessor class or machine model), +as determined at run time\&. +.TP +\fBEGID\fP <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 `\fB(EGID=\fP\fIgid\fP\fB; command)\fP\&' +.RS +.PP +If this is made local, it is not implicitly set to 0, but may be +explicitly set locally\&. +.RE +.TP +\fBEUID\fP <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 `\fB(EUID=\fP\fIuid\fP\fB; command)\fP\&' +.RS +.PP +If this is made local, it is not implicitly set to 0, but may be +explicitly set locally\&. +.RE +.TP +\fBERRNO\fP <S> +The value of errno (see \fIerrno\fP(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 \fBzsh/system\fP module which +allows the number to be turned into a name or message\&. +.TP +\fBFUNCNEST\fP <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\&. +.TP +\fBGID\fP <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 `\fB(GID=\fP\fIgid\fP\fB; command)\fP\&' +.RS +.PP +If this is made local, it is not implicitly set to 0, but may be +explicitly set locally\&. +.RE +.TP +\fBHISTCMD\fP +The current history event number in an interactive shell, in other +words the event number for the command that caused \fB$HISTCMD\fP +to be read\&. If the current history event modifies the history, +\fBHISTCMD\fP changes to the new maximum history event number\&. +.TP +\fBHOST\fP +The current hostname\&. +.TP +\fBLINENO\fP <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 \fBfunctions\fP builtin\&. +.TP +\fBLOGNAME\fP +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 \fBtypeset\fP builtin\&. The value +is set to the string returned by the \fIgetlogin\fP(3) system call +if that is available\&. +.TP +\fBMACHTYPE\fP +The machine type (microprocessor class or machine model), +as determined at compile time\&. +.TP +\fBOLDPWD\fP +The previous working directory\&. This is set when the shell initializes +and whenever the directory changes\&. +.TP +\fBOPTARG\fP <S> +The value of the last option argument processed by the \fBgetopts\fP +command\&. +.TP +\fBOPTIND\fP <S> +The index of the last option argument processed by the \fBgetopts\fP +command\&. +.TP +\fBOSTYPE\fP +The operating system, as determined at compile time\&. +.TP +\fBPPID\fP <S> +The process ID of the parent of the shell\&. As for \fB$$\fP, the +value indicates the parent of the original shell and does not +change in subshells\&. +.TP +\fBPWD\fP +The present working directory\&. This is set when the shell initializes +and whenever the directory changes\&. +.TP +\fBRANDOM\fP <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 \fBRANDOM\fP\&. +.RS +.PP +The values of \fBRANDOM\fP form an intentionally\-repeatable pseudo\-random +sequence; subshells that reference \fBRANDOM\fP will result +in identical pseudo\-random values unless the value of \fBRANDOM\fP is +referenced or seeded in the parent shell in between subshell invocations\&. +.RE +.TP +\fBSECONDS\fP <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\&. +.RS +.PP +Unlike other special parameters, the type of the \fBSECONDS\fP parameter can +be changed using the \fBtypeset\fP command\&. Only integer and one of the +floating point types are allowed\&. For example, `\fBtypeset \-F SECONDS\fP\&' +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 \fBtypeset\fP\&. See +the documentation for the builtin \fBtypeset\fP in +\fIzshbuiltins\fP(1) for more details\&. +.RE +.TP +\fBSHLVL\fP <S> +Incremented by one each time a new shell is started\&. +.TP +\fBsignals\fP +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 +\fBHUP\fP is signal number 1, but is referred to as \fB$signals[2]\fP\&. This +is because of \fBEXIT\fP at position 1 in the array, which is used +internally by zsh but is not known to the operating system\&. +.TP +\fBTRY_BLOCK_ERROR\fP <S> +In an \fBalways\fP 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 +\fIComplex Commands\fP in \fIzshmisc\fP(1) +.TP +\fBTRY_BLOCK_INTERRUPT\fP <S> +This variable works in a similar way to \fBTRY_BLOCK_ERROR\fP, but +represents the status of an interrupt from the signal SIGINT, which +typically comes from the keyboard when the user types \fB^C\fP\&. If set to +0, any such interrupt will be reset; otherwise, the interrupt is +propagated after the \fBalways\fP block\&. +.RS +.PP +Note that it is possible that an interrupt arrives during the execution +of the \fBalways\fP block; this interrupt is also propagated\&. +.RE +.TP +\fBTTY\fP +The name of the tty associated with the shell, if any\&. +.TP +\fBTTYIDLE\fP <S> +The idle time of the tty associated with the shell in seconds or \-1 if there +is no such tty\&. +.TP +\fBUID\fP <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 `\fB(UID=\fP\fIuid\fP\fB; command)\fP\&' +.RS +.PP +If this is made local, it is not implicitly set to 0, but may be +explicitly set locally\&. +.RE +.TP +\fBUSERNAME\fP <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 `\fB(USERNAME=\fP\fIusername\fP\fB; command)\fP\&' +.TP +\fBVENDOR\fP +The vendor, as determined at compile time\&. +.TP +\fBzsh_eval_context\fP <S> <Z> (\fBZSH_EVAL_CONTEXT\fP <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\&. +.RS +.PP +Note that the variable does not give information on syntactic context such +as pipelines or subshells\&. Use \fB$ZSH_SUBSHELL\fP to detect subshells\&. +.PP +The context is one of the following: +.PD 0 +.TP +.PD +\fBcmdarg\fP +Code specified by the \fB\-c\fP option to the command line that invoked +the shell\&. +.TP +\fBcmdsubst\fP +Command substitution using the \fB`\fP\fI\&.\&.\&.\fP\fB`\fP or +\fB$(\fP\fI\&.\&.\&.\fP\fB)\fP construct\&. +.TP +\fBequalsubst\fP +File substitution using the \fB=(\fP\fI\&.\&.\&.\fP\fB)\fP construct\&. +.TP +\fBeval\fP +Code executed by the \fBeval\fP builtin\&. +.TP +\fBevalautofunc\fP +Code executed with the \fBKSH_AUTOLOAD\fP mechanism in order to define +an autoloaded function\&. +.TP +\fBfc\fP +Code from the shell history executed by the \fB\-e\fP option to the \fBfc\fP +builtin\&. +.TP +\fBfile\fP +Lines of code being read directly from a file, for example by +the \fBsource\fP builtin\&. +.TP +\fBfilecode\fP +Lines of code being read from a \fB\&.zwc\fP file instead of directly +from the source file\&. +.TP +\fBglobqual\fP +Code executed by the \fBe\fP or \fB+\fP glob qualifier\&. +.TP +\fBglobsort\fP +Code executed to order files by the \fBo\fP glob qualifier\&. +.TP +\fBinsubst\fP +File substitution using the \fB<(\fP\fI\&.\&.\&.\fP\fB)\fP construct\&. +.TP +\fBloadautofunc\fP +Code read directly from a file to define an autoloaded function\&. +.TP +\fBoutsubst\fP +File substitution using the \fB>(\fP\fI\&.\&.\&.\fP\fB)\fP construct\&. +.TP +\fBsched\fP +Code executed by the \fBsched\fP builtin\&. +.TP +\fBshfunc\fP +A shell function\&. +.TP +\fBstty\fP +Code passed to \fBstty\fP by the \fBSTTY\fP environment variable\&. +Normally this is passed directly to the system\&'s \fBstty\fP command, +so this value is unlikely to be seen in practice\&. +.TP +\fBstyle\fP +Code executed as part of a style retrieved by the \fBzstyle\fP builtin +from the \fBzsh/zutil\fP module\&. +.TP +\fBtoplevel\fP +The highest execution level of a script or interactive shell\&. +.TP +\fBtrap\fP +Code executed as a trap defined by the \fBtrap\fP builtin\&. Traps +defined as functions have the context \fBshfunc\fP\&. As traps are +asynchronous they may have a different hierarchy from other +code\&. +.TP +\fBzpty\fP +Code executed by the \fBzpty\fP builtin from the \fBzsh/zpty\fP module\&. +.TP +\fBzregexparse\-guard\fP +Code executed as a guard by the \fBzregexparse\fP command from the +\fBzsh/zutil\fP module\&. +.TP +\fBzregexparse\-action\fP +Code executed as an action by the \fBzregexparse\fP command from the +\fBzsh/zutil\fP module\&. +.RE +.TP +\fBZSH_ARGZERO\fP +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 \fB$0\fP when the \fBPOSIX_ARGZERO\fP option is +set, but is always available\&. +.TP +\fBZSH_EXECUTION_STRING\fP +If the shell was started with the option \fB\-c\fP, this contains +the argument passed to the option\&. Otherwise it is not set\&. +.TP +\fBZSH_NAME\fP +Expands to the basename of the command used to invoke this instance +of zsh\&. +.TP +\fBZSH_PATCHLEVEL\fP +The output of `\fBgit describe \-\-tags \-\-long\fP\&' for the zsh repository +used to build the shell\&. This is most useful in order to keep +track of versions of the shell during development between releases; +hence most users should not use it and should instead rely on +\fB$ZSH_VERSION\fP\&. +.TP +\fBzsh_scheduled_events\fP +See the section `The zsh/sched Module\&' in \fIzshmodules\fP(1)\&. +.TP +\fBZSH_SCRIPT\fP +If zsh was invoked to run a script, this is the name of the script, +otherwise it is unset\&. +.TP +\fBZSH_SUBSHELL\fP +Readonly integer\&. Initially zero, incremented each time the shell forks +to create a subshell for executing code\&. Hence `\fB(print $ZSH_SUBSHELL)\fP\&' +and `\fBprint $(print $ZSH_SUBSHELL)\fP\&' output 1, while +`\fB( (print $ZSH_SUBSHELL) )\fP\&' outputs 2\&. +.TP +\fBZSH_VERSION\fP +The version number of the release of zsh\&. +.SH "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 \fBsh\fP or \fBksh\fP emulation mode\&. +.PP +In cases where there are two parameters with an upper\- and lowercase +form of the same name, such as \fBpath\fP and \fBPATH\fP, 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 `\fBtypeset \-T\fP\&'\&. 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\&. +.PP +.PD 0 +.TP +.PD +\fBARGV0\fP +If exported, its value is used as the \fBargv[0]\fP of external commands\&. +Usually used in constructs like `\fBARGV0=emacs nethack\fP\&'\&. +.TP +\fBBAUD\fP +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\&. +.RS +.PP +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\&. +.RE +.TP +\fBcdpath\fP <S> <Z> (\fBCDPATH\fP <S>) +An array (colon\-separated list) +of directories specifying the search path for the \fBcd\fP command\&. +.TP +\fBCOLUMNS\fP <S> +The number of columns for this terminal session\&. +Used for printing select lists and for the line editor\&. +.TP +\fBCORRECT_IGNORE\fP +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 `\fB_*\fP\&' then completion functions (which, by +convention, have names beginning with `\fB_\fP\&') will never be offered +as spelling corrections\&. The pattern does not apply to the correction +of file names, as applied by the \fBCORRECT_ALL\fP option (so with the +example just given files beginning with `\fB_\fP\&' in the current +directory would still be completed)\&. +.TP +\fBCORRECT_IGNORE_FILE\fP +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 `\fB\&.*\fP\&' then dot file names will never be +offered as spelling corrections\&. This is useful with the +\fBCORRECT_ALL\fP option\&. +.TP +\fBDIRSTACKSIZE\fP +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 \fBAUTO_PUSHD\fP option\&. +.TP +\fBENV\fP +If the \fBENV\fP environment variable is set when zsh is invoked as \fBsh\fP +or \fBksh\fP, \fB$ENV\fP is sourced after the profile scripts\&. The value of +\fBENV\fP is subjected to parameter expansion, command substitution, and +arithmetic expansion before being interpreted as a pathname\&. Note that +\fBENV\fP is \fInot\fP used unless the shell is interactive and zsh is +emulating \fBsh\fP or \fBksh\fP\&. +.TP +\fBFCEDIT\fP +The default editor for the \fBfc\fP builtin\&. If \fBFCEDIT\fP is not set, +the parameter \fBEDITOR\fP is used; if that is not set either, a builtin +default, usually \fBvi\fP, is used\&. +.TP +\fBfignore\fP <S> <Z> (\fBFIGNORE\fP <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\&. +.TP +\fBfpath\fP <S> <Z> (\fBFPATH\fP <S>) +An array (colon separated list) +of directories specifying the search path for +function definitions\&. This path is searched when a function +with the \fB\-u\fP attribute is referenced\&. If an executable +file is found, then it is read and executed in the current environment\&. +.TP +\fBhistchars\fP <S> +Three characters used by the shell\&'s history and lexical analysis +mechanism\&. The first character signals the start of a history +expansion (default `\fB!\fP\&')\&. The second character signals the +start of a quick history substitution (default `\fB^\fP\&')\&. The third +character is the comment character (default `\fB#\fP\&')\&. +.RS +.PP +The characters must be in the ASCII character set; any attempt to set +\fBhistchars\fP to characters with a locale\-dependent meaning will be +rejected with an error message\&. +.RE +.TP +\fBHISTCHARS\fP <S> <Z> +Same as \fBhistchars\fP\&. (Deprecated\&.) +.TP +\fBHISTFILE\fP +The file to save the history in when an interactive shell exits\&. +If unset, the history is not saved\&. +.TP +\fBHISTORY_IGNORE\fP +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 `\fBfc *\fP\&' then commands that invoke the +interactive history editor are never written to the history file\&. +.RS +.PP +Note that \fBHISTORY_IGNORE\fP defines a single pattern: to +specify alternatives use the +`\fB(\fP\fIfirst\fP\fB|\fP\fIsecond\fP\fB|\fP\fI\&.\&.\&.\fP\fB)\fP\&' syntax\&. +.PP +Compare the \fBHIST_NO_STORE\fP option or the \fBzshaddhistory\fP hook, +either of which would prevent such commands from being added to the +interactive history at all\&. If you wish to use \fBHISTORY_IGNORE\fP to +stop history being added in the first place, you can define the +following hook: +.PP +.RS +.nf +\fBzshaddhistory() { + emulate \-L zsh + ## uncomment if HISTORY_IGNORE + ## should use EXTENDED_GLOB syntax + # setopt extendedglob + [[ $1 != ${~HISTORY_IGNORE} ]] +}\fP +.fi +.RE +.RE +.TP +\fBHISTSIZE\fP <S> +The maximum number of events stored in the internal history list\&. +If you use the \fBHIST_EXPIRE_DUPS_FIRST\fP option, setting this value +larger than the \fBSAVEHIST\fP size will give you the difference as a +cushion for saving duplicated history events\&. +.RS +.PP +If this is made local, it is not implicitly set to 0, but may be +explicitly set locally\&. +.RE +.TP +\fBHOME\fP <S> +The default argument for the \fBcd\fP command\&. This is not set automatically +by the shell in \fBsh\fP, \fBksh\fP or \fBcsh\fP emulation, but it is typically +present in the environment anyway, and if it becomes set it has its usual +special behaviour\&. +.TP +\fBIFS\fP <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 \fBread\fP builtin\&. Any characters from the set space, tab and +newline that appear in the IFS are called \fIIFS white space\fP\&. +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\&. +.RS +.PP +If the parameter is unset, the default is used\&. Note this has +a different effect from setting the parameter to an empty string\&. +.RE +.TP +\fBKEYBOARD_HACK\fP +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 \fBSUNKEYBOARDHACK\fP 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\&. +.RS +.PP +For backward compatibility, if the \fBSUNKEYBOARDHACK\fP option is +explicitly set, the value of \fBKEYBOARD_HACK\fP reverts to backquote\&. +If the option is explicitly unset, this variable is set to empty\&. +.RE +.TP +\fBKEYTIMEOUT\fP +The time the shell waits, in hundredths of seconds, for another key to +be pressed when reading bound multi\-character sequences\&. +.TP +\fBLANG\fP <S> +This variable determines the locale category for any category not +specifically selected via a variable starting with `\fBLC_\fP\&'\&. +.TP +\fBLC_ALL\fP <S> +This variable overrides the value of the `\fBLANG\fP\&' variable and the value +of any of the other variables starting with `\fBLC_\fP\&'\&. +.TP +\fBLC_COLLATE\fP <S> +This variable determines the locale category for character collation +information within ranges in glob brackets and for sorting\&. +.TP +\fBLC_CTYPE\fP <S> +This variable determines the locale category for character handling +functions\&. If the \fBMULTIBYTE\fP option is in effect this variable or +\fBLANG\fP 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 \fBen_US\&.iso88591\fP (certain +Linux distributions) or \fBen_US\&.ISO8859\-1\fP (MacOS)\&. +.TP +\fBLC_MESSAGES\fP <S> +This variable determines the language in which messages should be +written\&. Note that zsh does not use message catalogs\&. +.TP +\fBLC_NUMERIC\fP <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\&. +.TP +\fBLC_TIME\fP <S> +This variable determines the locale category for date and time +formatting in prompt escape sequences\&. +.TP +\fBLINES\fP <S> +The number of lines for this terminal session\&. +Used for printing select lists and for the line editor\&. +.TP +\fBLISTMAX\fP +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\&. +.TP +\fBLOGCHECK\fP +The interval in seconds between checks for login/logout activity +using the \fBwatch\fP parameter\&. +.TP +\fBMAIL\fP +If this parameter is set and \fBmailpath\fP is not set, +the shell looks for mail in the specified file\&. +.TP +\fBMAILCHECK\fP +The interval in seconds between checks for new mail\&. +.TP +\fBmailpath\fP <S> <Z> (\fBMAILPATH\fP <S>) +An array (colon\-separated list) of filenames to check for +new mail\&. Each filename can be followed by a `\fB?\fP\&' and a +message that will be printed\&. The message will undergo +parameter expansion, command substitution and arithmetic +expansion with the variable \fB$_\fP defined as the name +of the file that has changed\&. The default message is +`\fBYou have new mail\fP\&'\&. If an element is a directory +instead of a file the shell will recursively check every +file in every subdirectory of the element\&. +.TP +\fBmanpath\fP <S> <Z> (\fBMANPATH\fP <S> <Z>) +An array (colon\-separated list) +whose value is not used by the shell\&. The \fBmanpath\fP +array can be useful, however, since setting it also sets +\fBMANPATH\fP, and vice versa\&. +.TP +.PD 0 +\fBmatch\fP +.TP +.PD 0 +\fBmbegin\fP +.TP +.PD +\fBmend\fP +Arrays set by the shell when the \fBb\fP globbing flag is used in pattern +matches\&. See the subsection \fIGlobbing flags\fP in +the documentation for \fIFilename Generation\fP in \fIzshexpn\fP(1)\&. +.TP +.PD 0 +\fBMATCH\fP +.TP +.PD 0 +\fBMBEGIN\fP +.TP +.PD +\fBMEND\fP +Set by the shell when the \fBm\fP globbing flag is used in pattern +matches\&. See the subsection \fIGlobbing flags\fP in +the documentation for \fIFilename Generation\fP in \fIzshexpn\fP(1)\&. +.TP +\fBmodule_path\fP <S> <Z> (\fBMODULE_PATH\fP <S>) +An array (colon\-separated list) +of directories that \fBzmodload\fP +searches for dynamically loadable modules\&. +This is initialized to a standard pathname, +usually `\fB/usr/local/lib/zsh/$ZSH_VERSION\fP\&'\&. +(The `\fB/usr/local/lib\fP\&' part varies from installation to installation\&.) +For security reasons, any value set in the environment when the shell +is started will be ignored\&. +.RS +.PP +These parameters only exist if the installation supports dynamic +module loading\&. +.RE +.TP +\fBNULLCMD\fP <S> +The command name to assume if a redirection is specified +with no command\&. Defaults to \fBcat\fP\&. For \fBsh\fP/\fBksh\fP +behavior, change this to \fB:\fP\&. For \fBcsh\fP\-like +behavior, unset this parameter; the shell will print an +error message if null commands are entered\&. +.TP +\fBpath\fP <S> <Z> (\fBPATH\fP <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\&. +.TP +\fBPOSTEDIT\fP <S> +This string is output whenever the line editor exits\&. +It usually contains termcap strings to reset the terminal\&. +.TP +.PD 0 +\fBPROMPT\fP <S> <Z> +.TP +.PD 0 +\fBPROMPT2\fP <S> <Z> +.TP +.PD 0 +\fBPROMPT3\fP <S> <Z> +.TP +.PD +\fBPROMPT4\fP <S> <Z> +Same as \fBPS1\fP, \fBPS2\fP, \fBPS3\fP and \fBPS4\fP, +respectively\&. +.TP +\fBprompt\fP <S> <Z> +Same as \fBPS1\fP\&. +.TP +\fBPROMPT_EOL_MARK\fP +When the \fBPROMPT_CR\fP and \fBPROMPT_SP\fP options are set, the +\fBPROMPT_EOL_MARK\fP parameter can be used to customize how the end of +partial lines are shown\&. This parameter undergoes prompt expansion, with +the \fBPROMPT_PERCENT\fP option set\&. If not set, the default behavior is +equivalent to the value `\fB%B%S%#%s%b\fP\&'\&. +.TP +\fBPS1\fP <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 \fIzshmisc\fP(1)\&. The default is `\fB%m%# \fP\&'\&. +.TP +\fBPS2\fP <S> +The secondary prompt, printed when the shell needs more information +to complete a command\&. +It is expanded in the same way as \fBPS1\fP\&. +The default is `\fB%_> \fP\&', which displays any shell constructs or quotation +marks which are currently being processed\&. +.TP +\fBPS3\fP <S> +Selection prompt used within a \fBselect\fP loop\&. +It is expanded in the same way as \fBPS1\fP\&. +The default is `\fB?# \fP\&'\&. +.TP +\fBPS4\fP <S> +The execution trace prompt\&. Default is `\fB+%N:%i> \fP\&', which displays +the name of the current shell structure and the line number within it\&. +In sh or ksh emulation, the default is `\fB+ \fP\&'\&. +.TP +\fBpsvar\fP <S> <Z> (\fBPSVAR\fP <S>) +An array (colon\-separated list) whose elements can be used in +\fBPROMPT\fP strings\&. Setting \fBpsvar\fP also sets \fBPSVAR\fP, and +vice versa\&. +.TP +\fBREADNULLCMD\fP <S> +The command name to assume if a single input redirection +is specified with no command\&. Defaults to \fBmore\fP\&. +.TP +\fBREPORTMEMORY\fP +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 \fBTIMEFMT\fP parameter, which is the same +as for the \fBREPORTTIME\fP variable and the \fBtime\fP builtin; note that +by default this does not output memory usage\&. Appending +\fB" max RSS %M"\fP to the value of \fBTIMEFMT\fP causes it to output the +value that triggered the report\&. If \fBREPORTTIME\fP is also in use, +at most a single report is printed for both triggers\&. This feature +requires the \fBgetrusage()\fP system call, commonly supported by +modern Unix\-like systems\&. +.TP +\fBREPORTTIME\fP +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 \fBtime\fP keyword still cause the summary +to be printed in this case\&. +.TP +\fBREPLY\fP +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 \fBread\fP builtin and the +\fBselect\fP complex command may set \fBREPLY\fP, and filename generation both +sets and examines its value when evaluating certain expressions\&. Some +modules also employ \fBREPLY\fP for similar purposes\&. +.TP +\fBreply\fP +As \fBREPLY\fP, but for array values rather than strings\&. +.TP +.PD 0 +\fBRPROMPT\fP <S> +.TP +.PD +\fBRPS1\fP <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 \fBSINGLE_LINE_ZLE\fP option is set\&. +It is expanded in the same way as \fBPS1\fP\&. +.TP +.PD 0 +\fBRPROMPT2\fP <S> +.TP +.PD +\fBRPS2\fP <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 \fBSINGLE_LINE_ZLE\fP option is set\&. +It is expanded in the same way as \fBPS2\fP\&. +.TP +\fBSAVEHIST\fP +The maximum number of history events to save in the history file\&. +.RS +.PP +If this is made local, it is not implicitly set to 0, but may be +explicitly set locally\&. +.RE +.TP +\fBSPROMPT\fP <S> +The prompt used for spelling correction\&. The sequence +`\fB%R\fP\&' expands to the string which presumably needs spelling +correction, and `\fB%r\fP\&' expands to the proposed correction\&. +All other prompt escapes are also allowed\&. +.RS +.PP +The actions available at the prompt are \fB[nyae]\fP: +.PD 0 +.TP +\fBn\fP (`no\&') (default) +Discard the correction and run the command\&. +.TP +\fBy\fP (`yes\&') +Make the correction and run the command\&. +.TP +\fBa\fP (`abort\&') +Discard the entire command line without running it\&. +.TP +\fBe\fP (`edit\&') +Resume editing the command line\&. +.PD +.RE +.TP +\fBSTTY\fP +If this parameter is set in a command\&'s environment, the shell runs the +\fBstty\fP 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 \fBfg\fP or \fBwait\fP builtins it will +see the modes specified by \fBSTTY\fP, as if it were not suspended\&. This +(intentionally) does not apply if the command is continued via `\fBkill +\-CONT\fP\&'\&. \fBSTTY\fP 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 \fBSTTY\fP should not be used for +window size specifications; these will not be local to the command\&. +.TP +\fBTERM\fP <S> +The type of terminal in use\&. This is used when looking up termcap +sequences\&. An assignment to \fBTERM\fP causes zsh to re\-initialize the +terminal, even if the value does not change (e\&.g\&., `\fBTERM=$TERM\fP\&')\&. 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\&. +.TP +\fBTERMINFO\fP <S> +A reference to your terminfo database, used by the `terminfo\&' library when the +system has it; see \fIterminfo\fP(5)\&. +If set, this causes the shell to reinitialise the terminal, making the +workaround `\fBTERM=$TERM\fP\&' unnecessary\&. +.TP +\fBTERMINFO_DIRS\fP <S> +A colon\-seprarated list of terminfo databases, used by the `terminfo\&' library +when the system has it; see \fIterminfo\fP(5)\&. This variable is only +used by certain terminal libraries, in particular ncurses; see +\fIterminfo\fP(5) to check support on your system\&. If set, this +causes the shell to reinitialise the terminal, making the workaround +`\fBTERM=$TERM\fP\&' unnecessary\&. Note that unlike other colon\-separated +arrays this is not tied to a zsh array\&. +.TP +\fBTIMEFMT\fP +The format of process time reports with the \fBtime\fP keyword\&. +The default is `\fB%J %U user %S system %P cpu %*E total\fP\&'\&. +Recognizes the following escape sequences, although not all +may be available on all systems, and some that are available +may not be useful: +.RS +.PP +.PD 0 +.TP +\fB%%\fP +A `\fB%\fP\&'\&. +.TP +\fB%U\fP +CPU seconds spent in user mode\&. +.TP +\fB%S\fP +CPU seconds spent in kernel mode\&. +.TP +\fB%E\fP +Elapsed time in seconds\&. +.TP +\fB%P\fP +The CPU percentage, computed as +100*(\fB%U\fP+\fB%S\fP)/\fB%E\fP\&. +.TP +\fB%W\fP +Number of times the process was swapped\&. +.TP +\fB%X\fP +The average amount in (shared) text space used in kilobytes\&. +.TP +\fB%D\fP +The average amount in (unshared) data/stack space used in +kilobytes\&. +.TP +\fB%K\fP +The total space used (\fB%X\fP+\fB%D\fP) in kilobytes\&. +.TP +\fB%M\fP +The maximum memory the process had in use at any time in +kilobytes\&. +.TP +\fB%F\fP +The number of major page faults (page needed to be brought +from disk)\&. +.TP +\fB%R\fP +The number of minor page faults\&. +.TP +\fB%I\fP +The number of input operations\&. +.TP +\fB%O\fP +The number of output operations\&. +.TP +\fB%r\fP +The number of socket messages received\&. +.TP +\fB%s\fP +The number of socket messages sent\&. +.TP +\fB%k\fP +The number of signals received\&. +.TP +\fB%w\fP +Number of voluntary context switches (waits)\&. +.TP +\fB%c\fP +Number of involuntary context switches\&. +.TP +\fB%J\fP +The name of this job\&. +.PD +.PP +A star may be inserted between the percent sign and flags printing time +(e\&.g\&., `\fB%*E\fP\&'); this causes the time to be printed in +`\fIhh\fP\fB:\fP\fImm\fP\fB:\fP\fIss\fP\fB\&.\fP\fIttt\fP\&' +format (hours and minutes are only printed if they are not zero)\&. +Alternatively, `\fBm\fP\&' or `\fBu\fP' may be used (e\&.g\&., `\fB%mE\fP') to produce +time output in milliseconds or microseconds, respectively\&. +.RE +.TP +\fBTMOUT\fP +If this parameter is nonzero, the shell will receive an \fBALRM\fP +signal if a command is not entered within the specified number of +seconds after issuing a prompt\&. If there is a trap on \fBSIGALRM\fP, it +will be executed and a new alarm is scheduled using the value of the +\fBTMOUT\fP 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 +\fBTMOUT\fP parameter, zsh terminates\&. Otherwise a new alarm is +scheduled to \fBTMOUT\fP seconds after the last keypress\&. +.TP +\fBTMPPREFIX\fP +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 `\fB/tmp/zsh\fP\&'\&. +.TP +\fBTMPSUFFIX\fP +A filename suffix which the shell will use for temporary files created +by process substitutions (e\&.g\&., `\fB=(\fIlist\fP)\fP\&')\&. +Note that the value should include a leading dot `\fB\&.\fP\&' 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\&. +.TP +\fBwatch\fP <S> <Z> (\fBWATCH\fP <S>) +An array (colon\-separated list) of login/logout events to report\&. +.RS +.PP +If it contains the single word `\fBall\fP\&', then all login/logout events +are reported\&. If it contains the single word `\fBnotme\fP\&', then all +events are reported as with `\fBall\fP\&' except \fB$USERNAME\fP\&. +.PP +An entry in this list may consist of a username, +an `\fB@\fP\&' followed by a remote hostname, +and a `\fB%\fP\&' followed by a line (tty)\&. Any of these may +be a pattern (be sure to quote this during the assignment to +\fBwatch\fP so that it does not immediately perform file generation); +the setting of the \fBEXTENDED_GLOB\fP option is respected\&. +Any or all of these components may be present in an entry; +if a login/logout event matches all of them, +it is reported\&. +.PP +For example, with the \fBEXTENDED_GLOB\fP option set, the following: +.PP +.RS +.nf +\fBwatch=(\&'^(pws|barts)')\fP +.fi +.RE +.PP +causes reports for activity associated with any user other than \fBpws\fP +or \fBbarts\fP\&. +.RE +.TP +\fBWATCHFMT\fP +The format of login/logout reports if the \fBwatch\fP parameter is set\&. +Default is `\fB%n has %a %l from %m\fP\&'\&. +Recognizes the following escape sequences: +.RS +.PP +.PD 0 +.TP +.PD +\fB%n\fP +The name of the user that logged in/out\&. +.TP +\fB%a\fP +The observed action, i\&.e\&. "logged on" or "logged off"\&. +.TP +\fB%l\fP +The line (tty) the user is logged in on\&. +.TP +\fB%M\fP +The full hostname of the remote host\&. +.TP +\fB%m\fP +The hostname up to the first `\fB\&.\fP\&'\&. If only the +IP address is available or the utmp field contains +the name of an X\-windows display, the whole name is printed\&. +.RS +.PP +\fINOTE:\fP +The `\fB%m\fP\&' and `\fB%M\fP' escapes will work only if there is a host name +field in the utmp on your machine\&. Otherwise they are +treated as ordinary strings\&. +.RE +.TP +\fB%S\fP (\fB%s\fP) +Start (stop) standout mode\&. +.TP +\fB%U\fP (\fB%u\fP) +Start (stop) underline mode\&. +.TP +\fB%B\fP (\fB%b\fP) +Start (stop) boldface mode\&. +.TP +.PD 0 +\fB%t\fP +.TP +.PD +\fB%@\fP +The time, in 12\-hour, am/pm format\&. +.TP +\fB%T\fP +The time, in 24\-hour format\&. +.TP +\fB%w\fP +The date in `\fIday\fP\fB\-\fP\fIdd\fP\&' format\&. +.TP +\fB%W\fP +The date in `\fImm\fP\fB/\fP\fIdd\fP\fB/\fP\fIyy\fP\&' format\&. +.TP +\fB%D\fP +The date in `\fIyy\fP\fB\-\fP\fImm\fP\fB\-\fP\fIdd\fP\&' format\&. +.TP +\fB%D{\fP\fIstring\fP\fB}\fP +The date formatted as \fIstring\fP using the \fBstrftime\fP function, with +zsh extensions as described by +EXPANSION OF PROMPT SEQUENCES in \fIzshmisc\fP(1)\&. +.TP +\fB%(\fP\fIx\fP\fB:\fP\fItrue\-text\fP\fB:\fP\fIfalse\-text\fP\fB)\fP +Specifies a ternary expression\&. +The character following the \fIx\fP is +arbitrary; the same character is used to separate the text +for the "true" result from that for the "false" result\&. +Both the separator and the right parenthesis may be escaped +with a backslash\&. +Ternary expressions may be nested\&. +.RS +.PP +The test character \fIx\fP may be any one of `\fBl\fP\&', `\fBn\fP', `\fBm\fP' +or `\fBM\fP\&', which indicate a `true' result if the corresponding +escape sequence would return a non\-empty value; or it may be `\fBa\fP\&', +which indicates a `true\&' result if the watched user has logged in, +or `false\&' if he has logged out\&. +Other characters evaluate to neither true nor false; the entire +expression is omitted in this case\&. +.PP +If the result is `true\&', then the \fItrue\-text\fP +is formatted according to the rules above and printed, +and the \fIfalse\-text\fP is skipped\&. +If `false\&', the \fItrue\-text\fP is skipped and the \fIfalse\-text\fP +is formatted and printed\&. +Either or both of the branches may be empty, but +both separators must be present in any case\&. +.RE +.RE +.TP +\fBWORDCHARS\fP <S> +A list of non\-alphanumeric characters considered part of a word +by the line editor\&. +.TP +\fBZBEEP\fP +If set, this gives a string of characters, which can use all the same codes +as the \fBbindkey\fP command as described in +the zsh/zle module entry in \fIzshmodules\fP(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 `\fB\ee[?5h\ee[?5l\fP\&' 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 `\fB\ee[?5l\ee[?5h\fP\&' instead)\&. This takes +precedence over the \fBNOBEEP\fP option\&. +.TP +\fBZDOTDIR\fP +The directory to search for shell startup files (\&.zshrc, etc), +if not \fB$HOME\fP\&. +.TP +\fBzle_bracketed_paste\fP +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\&. +.RS +.PP +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\&. +.RE +.TP +\fBzle_highlight\fP +An array describing contexts in which ZLE should highlight the input text\&. +See \fICharacter Highlighting\fP in \fIzshzle\fP(1)\&. +.TP +\fBZLE_LINE_ABORTED\fP +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\&. +`\fBprint \-zr \-\- $ZLE_LINE_ABORTED\fP\&' can be used to recover the line\&. +Only the most recent line of this kind is remembered\&. +.TP +.PD 0 +\fBZLE_REMOVE_SUFFIX_CHARS\fP +.TP +.PD +\fBZLE_SPACE_SUFFIX_CHARS\fP +These parameters are used by the line editor\&. In certain circumstances +suffixes (typically space or slash) added by the completion system +will be removed automatically, either because the next editing command +was not an insertable character, or because the character was marked +as requiring the suffix to be removed\&. +.RS +.PP +These variables can contain the sets of characters that will cause the +suffix to be removed\&. If \fBZLE_REMOVE_SUFFIX_CHARS\fP is set, those +characters will cause the suffix to be removed; if +\fBZLE_SPACE_SUFFIX_CHARS\fP is set, those characters will cause the +suffix to be removed and replaced by a space\&. +.PP +If \fBZLE_REMOVE_SUFFIX_CHARS\fP is not set, the default behaviour is +equivalent to: +.PP +.RS +.nf +\fBZLE_REMOVE_SUFFIX_CHARS=$\&' \et\en;&|'\fP +.fi +.RE +.PP +If \fBZLE_REMOVE_SUFFIX_CHARS\fP is set but is empty, no characters have this +behaviour\&. \fBZLE_SPACE_SUFFIX_CHARS\fP takes precedence, so that the +following: +.PP +.RS +.nf +\fBZLE_SPACE_SUFFIX_CHARS=$\&'&|'\fP +.fi +.RE +.PP +causes the characters `\fB&\fP\&' and `\fB|\fP' to remove the suffix but to +replace it with a space\&. +.PP +To illustrate the difference, suppose that the option \fBAUTO_REMOVE_SLASH\fP +is in effect and the directory \fBDIR\fP has just been completed, with an +appended \fB/\fP, following which the user types `\fB&\fP\&'\&. The default result +is `\fBDIR&\fP\&'\&. With \fBZLE_REMOVE_SUFFIX_CHARS\fP set but without including +`\fB&\fP\&' the result is `\fBDIR/&\fP'\&. With \fBZLE_SPACE_SUFFIX_CHARS\fP set to +include `\fB&\fP\&' the result is `\fBDIR &\fP'\&. +.PP +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 +\fIzshcompsys\fP(1)\&. +.RE +.TP +\fBZLE_RPROMPT_INDENT\fP <S> +If set, used to give the indentation between the right hand side of +the right prompt in the line editor as given by \fBRPS1\fP or \fBRPROMPT\fP +and the right hand side of the screen\&. If not set, the value 1 is used\&. +.RS +.PP +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\&. +.RE |