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zshparam(1)                                                        zshparam(1)


       zshparam - zsh parameters


       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 `!'.  The value may
       be a scalar (a string), an integer, an array (indexed numerically),  or
       an  associative array (an unordered set of name-value pairs, indexed by
       name).  To declare the type of a parameter, or to assign  a  scalar  or
       integer value to a parameter, use the typeset builtin.

       The  value  of  a  scalar  or integer parameter may also be assigned by


       If the integer attribute, -i, is set for name, the value is subject  to
       arithmetic  evaluation.   Furthermore,  by  replacing  `=' with `+=', a
       parameter can be added or appended to.  See the section `Array  Parame-
       ters' for additional forms of assignment.

       To  refer to the value of a parameter, write `$name' or `${name}'.  See
       Parameter Expansion in zshexpn(1) for complete details.

       In the parameter lists that follow, the mark `<S>' indicates  that  the
       parameter  is  special.   Special  parameters  cannot  have  their type
       changed or their readonly attribute turned off, and if a special param-
       eter  is  unset,  then  later recreated, the special properties will be
       retained.  `<Z>' indicates that the parameter does not exist  when  the
       shell initializes in sh or ksh emulation mode.


       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.  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.

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

              set -A 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 expan-
       sion 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  zsh-
       expn(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'.

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


       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 sup-
       ported 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  sin-
       gle-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 parame-
       ter 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.

              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 ele-
              ments 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,  respec-
              tively).   The subscript used is the number of the matching ele-
              ment, 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 ordi-
              nary 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'.

              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.

              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 sub-
              stitution 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.

       It  is  possible to avoid the use of subscripts in assignments to asso-
       ciative array elements by using the syntax:

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

       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.

       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 bal-
       anced  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  nor-
       mally required; for example, the pattern `[^[]' (to match any character
       other than an open bracket) should be written `[^\[]' in a reverse-sub-
       script 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  back-
       slash,  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

       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  dou-
       ble-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  associa-
       tive array key, the `e' flag must be used:

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

       A  last  detail  must  be  considered when reverse subscripting is per-
       formed.  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 back-
       slashes 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

       Note  that  the `k' and `K' flags are reverse subscripting for an ordi-
       nary 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

       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 sub-
       script syntax to extract a substring from a positional  parameter,  the
       expansion must be surrounded by braces; for example, `${2[3,5]}' evalu-
       ates 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]'.


       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 parameters *, @
       and argv are arrays containing  all  the  positional  parameters;  thus
       `$argv[n]', etc., is equivalent to simply `$n'.

       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 posi-
       tional 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 assign-
       ment  of  the  form  `n=(value  ...)' is allowed, and has the effect of
       shifting all the values at positions greater than n by  as  many  posi-
       tions as necessary to accommodate the new values.


       Shell function executions delimit scopes for shell parameters.  (Param-
       eters are dynamically scoped.)  The typeset builtin, and  its  alterna-
       tive  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 parame-
       ter  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  parame-
       ters were never exported has been removed.


       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 ${#} to resolve ambiguities.  In  par-
              ticular,  the  sequence  `$#-...' 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  sub-
              shells 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.   If  the  FUNC-
              TION_ARGZERO  option  is  set,  this is set temporarily within a
              shell function to the name of the function, and within a sourced
              script to the name of the script.

       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.

              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 suffi-
              cient 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)'

       EUID <S>
              The  effective user ID of the shell process.  If you have suffi-
              cient 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)'

       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 privi-
              leges), you may start a single command under a  different  group
              ID by `(GID=gid; command)'

              The  current  history  line  number  in an interactive shell, in
              other words the line number for the command that caused $HISTCMD
              to be read.

       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 func-
              tions builtin.

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

       OLDPWD The previous working directory.  This is set when the shell ini-
              tializes and whenever the directory changes.

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

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

       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 ini-
              tializes 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 parame-
              ter 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 float-
              ing  point  number.  The value is available to microsecond accu-
              racy, 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.

              An array containing the names of the signals.

              In an always block, indicates whether the preceding list of code
              caused  an error.  The value is 1 to indicate an error, 0 other-
              wise.  It may be reset, clearing the error condition.  See  Com-
              plex Commands in zshmisc(1)

       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)'

       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 privi-
              leges), you may start a single command under a  different  user-
              name  (and  user  ID  and group ID) by `(USERNAME=username; com-

       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.

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

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

              eval   Code executed by the eval builtin.

                     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  exam-
                     ple by the source builtin.

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

                     Code executed by the e or + glob qualifier.

                     Code executed to order files by the o glob qualifier.

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

                     Code read directly from a file to  define  an  autoloaded

                     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 prac-

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

                     The  highest  execution  level of a script or interactive

              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  hierar-
                     chy from other code.

              zpty   Code  executed by the zpty builtin from the zsh/zpty mod-

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

                     Code  executed  as  an  action by the zregexparse command
                     from the zsh/zutil module.

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

              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.

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

              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)' out-
              put 1, while `( (print $ZSH_SUBSHELL) )' outputs 2.

              The version number of the release of zsh.


       The following parameters are used by the shell.

       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 cre-
       ated 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 recre-
       ated, and recreating one of the pair will recreate the other.

       ARGV0  If exported, its value is used as the argv[0] of  external  com-
              mands.  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 neces-
              sary.  If the parameter is unset or the value is zero  the  com-
              pensation  mechanism is turned off.  The parameter is not set by

              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.

              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).

              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 comple-
              tion 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 exe-
              cutable file is found, then it is read and executed in the  cur-
              rent environment.

       histchars <S>
              Three  characters used by the shell's history and lexical analy-
              sis mechanism.  The first character signals the start of a  his-
              tory  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.)

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

       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  dif-
              ference as a cushion for saving duplicated history events.

       HOME <S>
              The  default argument for the cd command.  This is not set auto-
              matically 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.

              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 annoy-
              ingly 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 compabitility, 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

              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 col-
              lation information within ranges in glob brackets and for  sort-

       LC_CTYPE <S>
              This  variable determines the locale category for character han-
              dling functions.  If the MULTIBYTE  option  is  in  effect  this
              variable  or LANG should contain a value that reflects the char-
              acter 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

       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 print-
              ing select lists and for the line editor.

              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.

              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.

              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.

       mend   Arrays set by the shell when the b globbing flag is used in pat-
              tern matches.  See the subsection Globbing flags in the documen-
              tation for Filename Generation in zshexpn(1).

       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_VER-
              SION'.  (The `/usr/local/lib' part varies from  installation  to
              installation.)  For security reasons, any value set in the envi-
              ronment 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  usu-
              ally 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.

              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 informa-
              tion  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  dis-
              plays  the name of the current shell structure and the line num-
              ber within it.  In sh or ksh emulation, the default is `+ '.

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

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

              If  nonnegative,  commands whose combined user and system execu-
              tion 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  comple-
              tion;  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 evalu-
              ating  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.

              The maximum number of history events  to  save  in  the  history

       SPROMPT <S>
              The  prompt  used  for  spelling  correction.  The sequence `%R'
              expands to the string which presumably  needs  spelling  correc-
              tion,  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 argu-
              ments in order to set up the terminal before executing the  com-
              mand. The modes apply only to the command, and are reset when it
              finishes or is suspended. If the command is suspended  and  con-
              tinued  later with the fg or wait builtins it will see the modes
              specified by STTY, as if it were not  suspended.   This  (inten-
              tionally)  does  not apply if the command is continued via `kill
              -CONT'.  STTY is ignored if the command  is  run  in  the  back-
              ground,  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  specifi-
              cations; these will not be local to the command.

       TERM <S>
              The type of terminal in use.  This is used when looking up term-
              cap sequences.  An assignment to TERM causes zsh to  re-initial-
              ize  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, mak-
              ing the workaround `TERM=$TERM' unnecessary.

              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 avail-
              able on all systems, and some that are available may not be use-

              %%     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 kilo-
              %D     The average amount in (unshared) data/stack space used in
              %K     The total space used (%X+%D) in kilobytes.
              %M     The  maximum memory the process had in use at any time in
              %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 print-
              ing time.  This cause the time to be printed  in  `hh:mm:ss.ttt'
              format  (hours  and  minutes  are  only  printed if they are not

       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.   Other-
              wise  a  new  alarm is scheduled to TMOUT seconds after the last

              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

       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  or  all  of  these components may be present in an
              entry; if a login/logout  event  matches  all  of  them,  it  is

              The  format  of  login/logout  reports if the watch parameter is
              set.  Default is `%n has %a %l from %m'.  Recognizes the follow-
              ing 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.  Other-
                     wise they are treated as ordinary strings.

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

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

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

              %@     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.

                     Specifies  a ternary expression.  The character following
                     the x is arbitrary; the same character is used  to  sepa-
                     rate  the  text  for  the "true" result from that for the
                     "false" result.  Both the separator and the right  paren-
                     thesis  may be escaped with a backslash.  Ternary expres-
                     sions 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 termi-
              nal  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.

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

              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.

              These  parameters  are used by the line editor.  In certain cir-
              cumstances suffixes (typically space or slash) added by the com-
              pletion 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:


              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_SUF-
              FIX_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 zsh-

zsh 5.0.2                      December 21, 2012                   zshparam(1)

Mac OS X 10.9 - Generated Mon Oct 14 07:32:53 CDT 2013
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