Provided by: zsh-common_5.1.1-1ubuntu2_all bug

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 ...)

       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.  To append to an array without
       changing the existing values, use the syntax:

              name+=(value ...)

       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 ...)

       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 ...)

       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.

       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.  This flag
              may not be used with the i or I flag.

       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.

       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.

       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 following parameters are automatically set by the shell:

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

       # <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.  Note that this indicates the original shell started
              by invoking zsh; all processes forked from  the  shells  without  executing  a  new
              program, such as subshells started by (...), substitute the same value.

       - <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.

       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.  As for  $$,  the  value  indicates  the
              parent of the original shell and does not change in subshells.

       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.  Only integer and one of the floating  point  types  are
              allowed.   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.

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

       ZSH_PATCHLEVEL
              The revision string for the version  number  of  the  ChangeLog  file  in  the  zsh
              distribution.   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_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 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.

       LOGCHECK
              The interval in seconds between checks for login/logout activity  using  the  watch
              parameter.

       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.

       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.

       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.

       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  a  compiled  description  of the terminal, 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.

       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 megabytes.
              %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.   This
              cause  the  time to be printed in `hh:mm:ss.ttt' format (hours and minutes are only
              printed if they are not zero).

       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'.

       watch <S> <Z> (WATCH <S>)
              An array (colon-separated list) of login/logout events to report.

              If it contains the single word `all', then all login/logout  events  are  reported.
              If  it contains the single word `notme', then all events are reported as with `all'
              except $USERNAME.

              An entry in this list may consist of a  username,  an  `@'  followed  by  a  remote
              hostname,  and  a  `%' followed by a line (tty).  Any of these may be a pattern (be
              sure to quote this during the assignment to watch so that it does  not  immediately
              perform  file  generation);  the  setting of the EXTENDED_GLOB 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.

              For example, with the EXTENDED_GLOB option set, the following:

                     watch=('^(pws|barts)')

              causes reports for activity assoicated with any user other than pws or barts.

       WATCHFMT
              The  format  of login/logout reports if the watch parameter is set.  Default is `%n
              has %a %l from %m'.  Recognizes the following escape sequences:

              %n     The name of the user that logged in/out.

              %a     The observed action, i.e. "logged on" or "logged off".

              %l     The line (tty) the user is logged in on.

              %M     The full hostname of the remote host.

              %m     The hostname up to the first `.'.  If only the IP address  is  available  or
                     the  utmp field contains the name of an X-windows display, the whole name is
                     printed.

                     NOTE: The `%m' and `%M' escapes will work only if there is a host name field
                     in  the  utmp  on  your  machine.   Otherwise  they  are treated as ordinary
                     strings.

              %S (%s)
                     Start (stop) standout mode.

              %U (%u)
                     Start (stop) underline mode.

              %B (%b)
                     Start (stop) boldface mode.

              %t
              %@     The time, in 12-hour, am/pm format.

              %T     The time, in 24-hour format.

              %w     The date in `day-dd' format.

              %W     The date in `mm/dd/yy' format.

              %D     The date in `yy-mm-dd' format.

              %D{string}
                     The  date  formatted  as  string  using  the  strftime  function,  with  zsh
                     extensions as described by EXPANSION OF PROMPT SEQUENCES in zshmisc(1).

              %(x:true-text:false-text)
                     Specifies a ternary expression.  The character following the x 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.

                     The test character x may be any one of `l', `n', `m' or `M', which  indicate
                     a  `true'  result  if  the  corresponding  escape  sequence  would  return a
                     non-empty value; or it may be `a', 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.

                     If  the  result  is `true', then the true-text is formatted according to the
                     rules above and printed, and the false-text is  skipped.   If  `false',  the
                     true-text is skipped and the false-text is formatted and printed.  Either or
                     both of the branches may be empty, but both separators must  be  present  in
                     any case.

       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.