Provided by: zsh_4.3.11-4ubuntu2.is.3ubuntu2_i386 bug

NAME

       zshexpn - zsh expansion and substitution

DESCRIPTION

       The  following types of expansions are performed in the indicated order
       in five steps:

       History Expansion
              This is performed only in interactive shells.

       Alias Expansion
              Aliases are expanded immediately  before  the  command  line  is
              parsed as explained under Aliasing in zshmisc(1).

       Process Substitution
       Parameter Expansion
       Command Substitution
       Arithmetic Expansion
       Brace Expansion
              These  five  are performed in one step in left-to-right fashion.
              After  these  expansions,  all  unquoted  occurrences   of   the
              characters `\', `'' and `"' are removed.

       Filename Expansion
              If  the  SH_FILE_EXPANSION option is set, the order of expansion
              is modified for compatibility with sh and  ksh.   In  that  case
              filename   expansion   is   performed  immediately  after  alias
              expansion, preceding the set of five expansions mentioned above.

       Filename Generation
              This expansion, commonly referred to as globbing, is always done
              last.

       The following sections explain the types of expansion in detail.

HISTORY EXPANSION

       History  expansion  allows you to use words from previous command lines
       in  the  command  line  you  are  typing.   This  simplifies   spelling
       corrections  and  the  repetition of complicated commands or arguments.
       Immediately before execution, each command  is  saved  in  the  history
       list,  the  size of which is controlled by the HISTSIZE parameter.  The
       one most recent command is always retained in  any  case.   Each  saved
       command in the history list is called a history event and is assigned a
       number, beginning with 1 (one) when the shell starts up.   The  history
       number  that  you  may  see  in  your  prompt  (see EXPANSION OF PROMPT
       SEQUENCES in zshmisc(1)) is the number that is to be  assigned  to  the
       next command.

   Overview
       A  history  expansion  begins with the first character of the histchars
       parameter, which is `!' by default,  and  may  occur  anywhere  on  the
       command  line;  history expansions do not nest.  The `!' can be escaped
       with `\' or can be enclosed between a pair of  single  quotes  ('')  to
       suppress  its  special  meaning.  Double quotes will not work for this.
       Following this history character is an optional event  designator  (see
       the  section  `Event Designators') and then an optional word designator
       (the section `Word Designators'); if neither of  these  designators  is
       present, no history expansion occurs.

       Input  lines  containing  history  expansions  are  echoed  after being
       expanded, but before any other expansions take  place  and  before  the
       command  is executed.  It is this expanded form that is recorded as the
       history event for later references.

       By default, a history reference with no event designator refers to  the
       same  event as any preceding history reference on that command line; if
       it is the only history  reference  in  a  command,  it  refers  to  the
       previous  command.   However,  if the option CSH_JUNKIE_HISTORY is set,
       then every history reference with no event specification always  refers
       to the previous command.

       For  example,  `!' is the event designator for the previous command, so
       `!!:1' always refers to the first word of  the  previous  command,  and
       `!!$'  always  refers  to  the last word of the previous command.  With
       CSH_JUNKIE_HISTORY set, then `!:1' and `!$' function in the same manner
       as  `!!:1'  and `!!$', respectively.  Conversely, if CSH_JUNKIE_HISTORY
       is unset, then `!:1' and `!$'  refer  to  the  first  and  last  words,
       respectively, of the same event referenced by the nearest other history
       reference preceding them  on  the  current  command  line,  or  to  the
       previous command if there is no preceding reference.

       The  character  sequence  `^foo^bar'  (where `^' is actually the second
       character  of  the  histchars  parameter)  repeats  the  last  command,
       replacing  the  string  foo  with  bar.   More  precisely, the sequence
       `^foo^bar^' is synonymous with `!!:s^foo^bar^', hence  other  modifiers
       (see the section `Modifiers') may follow the final `^'.  In particular,
       `^foo^bar^:G' performs a global substitution.

       If the shell encounters the character sequence `!"' in the  input,  the
       history  mechanism  is temporarily disabled until the current list (see
       zshmisc(1)) is fully parsed.  The `!"' is removed from the  input,  and
       any subsequent `!' characters have no special significance.

       A  less  convenient  but  more  comprehensible  form of command history
       support is provided by the fc builtin.

   Event Designators
       An event designator is a reference  to  a  command-line  entry  in  the
       history list.  In the list below, remember that the initial `!' in each
       item may be changed to  another  character  by  setting  the  histchars
       parameter.

       !      Start  a  history  expansion,  except  when followed by a blank,
              newline,  `='  or  `('.   If  followed  immediately  by  a  word
              designator  (see  the  section `Word Designators'), this forms a
              history reference with no  event  designator  (see  the  section
              `Overview').

       !!     Refer  to  the  previous  command.   By  itself,  this expansion
              repeats the previous command.

       !n     Refer to command-line n.

       !-n    Refer to the current command-line minus n.

       !str   Refer to the most recent command starting with str.

       !?str[?]
              Refer to the most recent command containing str.   The  trailing
              `?'  is  necessary  if  this  reference  is  to be followed by a
              modifier or followed by any text that is not  to  be  considered
              part of str.

       !#     Refer  to the current command line typed in so far.  The line is
              treated as if it were complete up  to  and  including  the  word
              before the one with the `!#' reference.

       !{...} Insulate  a  history  reference  from  adjacent  characters  (if
              necessary).

   Word Designators
       A word designator indicates which word or words of a given command line
       are to be included in a history reference.  A `:' usually separates the
       event specification from the word designator.  It may be  omitted  only
       if  the  word designator begins with a `^', `$', `*', `-' or `%'.  Word
       designators include:

       0      The first input word (command).
       n      The nth argument.
       ^      The first argument.  That is, 1.
       $      The last argument.
       %      The word matched by (the most recent) ?str search.
       x-y    A range of words; x defaults to 0.
       *      All the arguments, or a null value if there are none.
       x*     Abbreviates `x-$'.
       x-     Like `x*' but omitting word $.

       Note that a `%' word designator works only when used in  one  of  `!%',
       `!:%'  or `!?str?:%', and only when used after a !? expansion (possibly
       in an earlier command).  Anything else results in  an  error,  although
       the error may not be the most obvious one.

   Modifiers
       After  the  optional  word designator, you can add a sequence of one or
       more of the  following  modifiers,  each  preceded  by  a  `:'.   These
       modifiers  also work on the result of filename generation and parameter
       expansion, except where noted.

       a      Turn a file name into an absolute path:   prepends  the  current
              directory, if necessary, and resolves any use of `..' and `.' in
              the path.  Note that the transformation takes place even if  the
              file or any intervening directories do not exist.

       A      As  `a',  but also resolve use of symbolic links where possible.
              Note  that  resolution  of  `..'  occurs  before  resolution  of
              symbolic links.  This call is equivalent to a unless your system
              has the realpath system call (modern systems do).

       c      Resolve a command name into an absolute path  by  searching  the
              command path given by the PATH variable.  This does not work for
              commands containing directory parts.  Note also that  this  does
              not  usually  work as a glob qualifier unless a file of the same
              name is found in the current directory.

       e      Remove all but the extension.

       h      Remove a trailing pathname component, leaving  the  head.   This
              works like `dirname'.

       l      Convert the words to all lowercase.

       p      Print  the  new  command but do not execute it.  Only works with
              history expansion.

       q      Quote the substituted  words,  escaping  further  substitutions.
              Works with history expansion and parameter expansion, though for
              parameters it is only useful if the  resulting  text  is  to  be
              re-evaluated such as by eval.

       Q      Remove one level of quotes from the substituted words.

       r      Remove a filename extension of the form `.xxx', leaving the root
              name.

       s/l/r[/]
              Substitute r for l as described below.  The substitution is done
              only  for  the  first string that matches l.  For arrays and for
              filename generation, this applies to each word of  the  expanded
              text.  See below for further notes on substitutions.

              The  forms  `gs/l/r' and `s/l/r/:G' perform global substitution,
              i.e. substitute every occurrence of r for l.  Note that the g or
              :G must appear in exactly the position shown.

              See further notes on this form of substitution below.

       &      Repeat  the  previous  s  substitution.  Like s, may be preceded
              immediately by a g.  In parameter expansion the  &  must  appear
              inside braces, and in filename generation it must be quoted with
              a backslash.

       t      Remove all leading pathname components, leaving the tail.   This
              works like `basename'.

       u      Convert the words to all uppercase.

       x      Like  q, but break into words at whitespace.  Does not work with
              parameter expansion.

       The s/l/r/ substitution works as follows.   By  default  the  left-hand
       side  of  substitutions  are  not patterns, but character strings.  Any
       character can be used as the delimiter in place of  `/'.   A  backslash
       quotes   the   delimiter   character.    The   character  `&',  in  the
       right-hand-side r, is replaced by the text from the  left-hand-side  l.
       The  `&'  can  be  quoted with a backslash.  A null l uses the previous
       string either from the previous l or from the contextual scan string  s
       from  `!?s'.   You  can  omit  the  rightmost  delimiter  if  a newline
       immediately follows  r;  the  rightmost  `?'  in  a  context  scan  can
       similarly  be  omitted.   Note  the  same record of the last l and r is
       maintained across all forms of expansion.

       Note that if a `&' is used within glob qualifers an extra backslash  is
       needed as a & is a special character in this case.

       If  the  option HIST_SUBST_PATTERN is set, l is treated as a pattern of
       the usual form described in  the  section  FILENAME  GENERATION  below.
       This can be used in all the places where modifiers are available; note,
       however, that in globbing qualifiers parameter substitution has already
       taken  place,  so parameters in the replacement string should be quoted
       to ensure they are replaced  at  the  correct  time.   Note  also  that
       complicated  patterns used in globbing qualifiers may need the extended
       glob qualifier notation (#q:s/.../.../)  in  order  for  the  shell  to
       recognize  the  expression as a glob qualifier.  Further, note that bad
       patterns in the substitution are  not  subject  to  the  NO_BAD_PATTERN
       option so will cause an error.

       When  HIST_SUBST_PATTERN  is set, l may start with a # to indicate that
       the pattern must match at the start of the string  to  be  substituted,
       and  a  %  may  appear  at the start or after an # to indicate that the
       pattern must match at the end of the string to be substituted.   The  %
       or # may be quoted with two backslashes.

       For  example,  the following piece of filename generation code with the
       EXTENDED_GLOB option:

              print *.c(#q:s/#%(#b)s(*).c/'S${match[1]}.C'/)

       takes the expansion of *.c and  applies  the  glob  qualifiers  in  the
       (#q...)  expression, which consists of a substitution modifier anchored
       to the start and end of each word (#%).  This turns  on  backreferences
       ((#b)),  so  that  the  parenthesised subexpression is available in the
       replacement string as ${match[1]}.  The replacement string is quoted so
       that  the  parameter  is  not  substituted before the start of filename
       generation.

       The following f,  F,  w  and  W  modifiers  work  only  with  parameter
       expansion  and  filename generation.  They are listed here to provide a
       single point of reference for all modifiers.

       f      Repeats the immediately (without  a  colon)  following  modifier
              until the resulting word doesn't change any more.

       F:expr:
              Like  f,  but  repeats  only  n  times  if  the  expression expr
              evaluates to n.  Any character can be used instead of  the  `:';
              if  `(',  `[',  or  `{'  is  used  as the opening delimiter, the
              closing delimiter should be ')', `]', or `}', respectively.

       w      Makes the immediately following modifier work on  each  word  in
              the string.

       W:sep: Like  w  but  words are considered to be the parts of the string
              that are separated by sep. Any character can be used instead  of
              the `:'; opening parentheses are handled specially, see above.

PROCESS SUBSTITUTION

       Each  part  of  a  command  argument  that  takes  the  form `<(list)',
       `>(list)'  or  `=(list)'  is  subject  to  process  substitution.   The
       expression  may  be preceeded or followed by other strings except that,
       to prevent clashes with commonly occurring strings  and  patterns,  the
       last  form must occur at the start of a command argument, and the forms
       are only expanded when first parsing command or  assignment  arguments.
       Process  substitutions  may be used following redirection operators; in
       this case, the substitution must appear with no trailing string.

       In the case of the < or > forms, the shell runs the commands in list as
       a  subprocess  of  the  job  executing  the shell command line.  If the
       system supports the /dev/fd mechanism, the command argument is the name
       of  the  device  file corresponding to a file descriptor; otherwise, if
       the system supports named pipes (FIFOs), the command argument will be a
       named  pipe.   If  the  form  with  >  is selected then writing on this
       special file will provide input for list.  If < is used, then the  file
       passed  as  an  argument  will  be  connected to the output of the list
       process.  For example,

              paste <(cut -f1 file1) <(cut -f3 file2) |
              tee >(process1) >(process2) >/dev/null

       cuts fields 1 and 3 from the files file1 and file2 respectively, pastes
       the  results  together,  and  sends  it  to  the processes process1 and
       process2.

       If =(...) is used instead  of  <(...),  then  the  file  passed  as  an
       argument  will be the name of a temporary file containing the output of
       the list process.  This may be used instead of the < form for a program
       that expects to lseek (see lseek(2)) on the input file.

       There is an optimisation for substitutions of the form =(<<<arg), where
       arg is a single-word argument to the here-string redirection <<<.  This
       form  produces  a  file  name  containing  the  value  of arg after any
       substitutions have been performed.  This is handled entirely within the
       current  shell.   This  is  effectively the reverse of the special form
       $(<arg) which treats arg as a file name and replaces it with the file's
       contents.

       The  =  form  is  useful  as  both  the  /dev/fd  and  the  named  pipe
       implementation of <(...) have drawbacks.   In  the  former  case,  some
       programmes  may  automatically  close  the  file descriptor in question
       before examining the file on the command line, particularly if this  is
       necessary  for  security  reasons such as when the programme is running
       setuid.  In the second case, if the programme does  not  actually  open
       the  file,  the  subshell  attempting to read from or write to the pipe
       will (in a typical implementation, different operating systems may have
       different  behaviour)  block for ever and have to be killed explicitly.
       In both cases, the shell actually  supplies  the  information  using  a
       pipe,  so  that  programmes  that expect to lseek (see lseek(2)) on the
       file will not work.

       Also  note  that  the  previous  example  can  be  more  compactly  and
       efficiently written (provided the MULTIOS option is set) as:

              paste <(cut -f1 file1) <(cut -f3 file2) \
              > >(process1) > >(process2)

       The  shell  uses  pipes  instead  of  FIFOs to implement the latter two
       process substitutions in the above example.

       There is an additional problem with >(process); when this  is  attached
       to  an  external command, the parent shell does not wait for process to
       finish and hence an immediately following command cannot  rely  on  the
       results  being  complete.   The  problem  and  solution are the same as
       described in the section MULTIOS in zshmisc(1).  Hence in a  simplified
       version of the example above:

              paste <(cut -f1 file1) <(cut -f3 file2) > >(process)

       (note that no MULTIOS are involved), process will be run asynchronously
       as far as the parent shell is concerned.  The workaround is:

              { paste <(cut -f1 file1) <(cut -f3 file2) } > >(process)

       The extra processes here are spawned from the parent shell  which  will
       wait for their completion.

PARAMETER EXPANSION

       The  character  `$'  is  used  to  introduce parameter expansions.  See
       zshparam(1)  for  a  description  of  parameters,   including   arrays,
       associative  arrays,  and subscript notation to access individual array
       elements.

       Note in particular the fact that words of unquoted parameters  are  not
       automatically  split  on  whitespace unless the option SH_WORD_SPLIT is
       set; see references to this option below for more details.  This is  an
       important difference from other shells.

       In  the  expansions discussed below that require a pattern, the form of
       the pattern is the same as that used for filename generation;  see  the
       section  `Filename  Generation'.   Note that these patterns, along with
       the replacement text of any substitutions, are  themselves  subject  to
       parameter  expansion,  command  substitution, and arithmetic expansion.
       In addition to the following operations, the colon modifiers  described
       in  the  section  `Modifiers' in the section `History Expansion' can be
       applied:  for example, ${i:s/foo/bar/} performs string substitution  on
       the expansion of parameter $i.

       ${name}
              The  value,  if  any, of the parameter name is substituted.  The
              braces are required if the expansion is  to  be  followed  by  a
              letter,  digit,  or  underscore that is not to be interpreted as
              part  of  name.   In  addition,  more   complicated   forms   of
              substitution   usually   require   the  braces  to  be  present;
              exceptions, which only apply if the  option  KSH_ARRAYS  is  not
              set,  are  a  single  subscript or any colon modifiers appearing
              after the name, or any of the characters `^', `=', `~',  `#'  or
              `+' appearing before the name, all of which work with or without
              braces.

              If name is an array parameter, and the KSH_ARRAYS option is  not
              set,  then the value of each element of name is substituted, one
              element per word.  Otherwise, the expansion results in one  word
              only;  with  KSH_ARRAYS,  this is the first element of an array.
              No  field  splitting  is  done  on   the   result   unless   the
              SH_WORD_SPLIT   option  is  set.   See  also  the  flags  =  and
              s:string:.

       ${+name}
              If name is the name of  a  set  parameter  `1'  is  substituted,
              otherwise `0' is substituted.

       ${name-word}
       ${name:-word}
              If  name  is  set,  or  in  the  second  form  is non-null, then
              substitute its value; otherwise substitute word.  In the  second
              form  name  may  be  omitted,  in  which  case  word  is  always
              substituted.

       ${name+word}
       ${name:+word}
              If name is  set,  or  in  the  second  form  is  non-null,  then
              substitute word; otherwise substitute nothing.

       ${name=word}
       ${name:=word}
       ${name::=word}
              In  the first form, if name is unset then set it to word; in the
              second form, if name is unset or null then set it to  word;  and
              in  the  third  form,  unconditionally set name to word.  In all
              forms, the value of the parameter is then substituted.

       ${name?word}
       ${name:?word}
              In the first form, if name is set, or in the second form if name
              is  both set and non-null, then substitute its value; otherwise,
              print word and exit from the shell.  Interactive shells  instead
              return  to  the  prompt.   If  word  is omitted, then a standard
              message is printed.

       In any of the above expressions that test a variable and substitute  an
       alternate  word,  note  that  you can use standard shell quoting in the
       word  value  to  selectively  override  the  splitting  done   by   the
       SH_WORD_SPLIT option and the = flag, but not splitting by the s:string:
       flag.

       In  the  following  expressions,  when  name  is  an  array   and   the
       substitution  is not quoted, or if the `(@)' flag or the name[@] syntax
       is used, matching and replacement is performed on  each  array  element
       separately.

       ${name#pattern}
       ${name##pattern}
              If  the pattern matches the beginning of the value of name, then
              substitute the value of name with the matched  portion  deleted;
              otherwise,  just  substitute  the  value  of name.  In the first
              form, the smallest matching pattern is preferred; in the  second
              form, the largest matching pattern is preferred.

       ${name%pattern}
       ${name%%pattern}
              If  the  pattern  matches  the  end  of  the value of name, then
              substitute the value of name with the matched  portion  deleted;
              otherwise,  just  substitute  the  value  of name.  In the first
              form, the smallest matching pattern is preferred; in the  second
              form, the largest matching pattern is preferred.

       ${name:#pattern}
              If  the  pattern  matches the value of name, then substitute the
              empty string; otherwise, just substitute the value of name.   If
              name  is  an  array the matching array elements are removed (use
              the `(M)' flag to remove the non-matched elements).

       ${name:offset}
       ${name:offset:length}
              This syntax gives effects similar to parameter  subscripting  in
              the  form $name{start,end}, but is compatible with other shells;
              note that both offset and  length  are  interpreted  differently
              from the components of a subscript.

              If offset is non-negative, then if the variable name is a scalar
              substitute the contents  starting  offset  characters  from  the
              first  character  of  the  string,  and  if  name  is  an  array
              substitute elements starting  offset  elements  from  the  first
              element.  If length is given, substitute that many characters or
              elements, otherwise the entire rest of the scalar or array.

              A positive offset is always treated as the offset of a character
              or  element  in  name from the first character or element of the
              array (this is different from native  zsh  subscript  notation).
              Hence  0  refers to the first character or element regardless of
              the setting of the option KSH_ARRAYS.

              A negative offset counts backwards from the end of the scalar or
              array,  so that -1 corresponds to the last character or element,
              and so on.

              length is always treated directly as a length and hence may  not
              be  negative.   The  option MULTIBYTE is obeyed, i.e. the offset
              and length count multibyte characters where appropriate.

              offset and length undergo the same set of shell substitutions as
              for  scalar  assignment;  in  addition, they are then subject to
              arithmetic evaluation.  Hence, for example

                     print ${foo:3}
                     print ${foo: 1 + 2}
                     print ${foo:$(( 1 + 2))}
                     print ${foo:$(echo 1 + 2)}

              all have the same effect, extracting the string starting at  the
              fourth  character  of  $foo  if  the  substution would otherwise
              return a scalar, or the array starting at the fourth element  if
              $foo   would  return  an  array.   Note  that  with  the  option
              KSH_ARRAYS $foo always returns a scalar (regardless of  the  use
              of  the  offset syntax) and a form such as $foo[*]:3 is required
              to extract elements of an array named foo.

              If offset is negative, the - may not  appear  immediately  after
              the  : as this indicates the ${name:-word} form of substitution.
              Instead, a space may be inserted  before  the  -.   Furthermore,
              neither offset nor length may begin with an alphabetic character
              or & as these are used to indicate history-style modifiers.   To
              substitute  a value from a variable, the recommended approach is
              to  proceed  it  with  a  $  as  this  signifies  the  intention
              (parameter  substitution  can  easily  be  rendered unreadable);
              however, as arithmetic substitution is performed, the expression
              ${var: offs} does work, retrieving the offset from $offs.

              For  further  compatibility with other shells there is a special
              case for array offset 0.  This usually  accesses  to  the  first
              element  of  the array.  However, if the substitution refers the
              positional parameter array, e.g. $@ or $*, then offset 0 instead
              refers to $0, offset 1 refers to $1, and so on.  In other words,
              the  positional  parameter  array  is  effectively  extended  by
              prepending  $0.   Hence  ${*:0:1}  substitutes  $0  and ${*:1:1}
              substitutes $1.

       ${name/pattern/repl}
       ${name//pattern/repl}
              Replace the longest possible match of pattern in  the  expansion
              of  parameter name by string repl.  The first form replaces just
              the first occurrence, the second  form  all  occurrences.   Both
              pattern  and  repl are subject to double-quoted substitution, so
              that expressions like ${name/$opat/$npat} will  work,  but  note
              the  usual rule that pattern characters in $opat are not treated
              specially unless either the option GLOB_SUBST is set,  or  $opat
              is instead substituted as ${~opat}.

              The pattern may begin with a `#', in which case the pattern must
              match at the start of the string, or `%', in which case it  must
              match  at  the  end  of  the  string,  or `#%' in which case the
              pattern must match the entire string.  The repl may be an  empty
              string,  in  which  case  the final `/' may also be omitted.  To
              quote the final `/' in other cases it should be  preceded  by  a
              single backslash; this is not necessary if the `/' occurs inside
              a substituted parameter.  Note also that the `#',  `%'  and  `#%
              are  not  active  if  they occur inside a substituted parameter,
              even at the start.

              The first `/' may be preceded by a `:', in which case the  match
              will  only succeed if it matches the entire word.  Note also the
              effect of the I and S parameter expansion flags below;  however,
              the flags M, R, B, E and N are not useful.

              For example,

                     foo="twinkle twinkle little star" sub="t*e" rep="spy"
                     print ${foo//${~sub}/$rep}
                     print ${(S)foo//${~sub}/$rep}

              Here,  the  `~'  ensures  that  the text of $sub is treated as a
              pattern rather than a plain string.   In  the  first  case,  the
              longest  match  for  t*e  is  substituted and the result is `spy
              star', while in the second case, the shortest matches are  taken
              and the result is `spy spy lispy star'.

       ${#spec}
              If spec is one of the above substitutions, substitute the length
              in characters of the result instead of the  result  itself.   If
              spec  is  an array expression, substitute the number of elements
              of the result.  Note that `^', `=', and `~', below, must  appear
              to the left of `#' when these forms are combined.

       ${^spec}
              Turn  on  the RC_EXPAND_PARAM option for the evaluation of spec;
              if the `^' is doubled, turn it off.  When this  option  is  set,
              array expansions of the form foo${xx}bar, where the parameter xx
              is set to  (a  b  c),  are  substituted  with  `fooabar  foobbar
              foocbar'  instead  of  the  default `fooa b cbar'.  Note that an
              empty array will therefore cause all arguments to be removed.

              Internally, each such expansion is converted into the equivalent
              list    for    brace    expansion.     E.g.,   ${^var}   becomes
              {$var[1],$var[2],...}, and is  processed  as  described  in  the
              section  `Brace  Expansion' below.  If word splitting is also in
              effect the $var[N] may themselves be split into  different  list
              elements.

       ${=spec}
              Perform  word splitting using the rules for SH_WORD_SPLIT during
              the evaluation of spec, but regardless of whether the  parameter
              appears  in  double  quotes; if the `=' is doubled, turn it off.
              This forces parameter expansions to be split into separate words
              before  substitution, using IFS as a delimiter.  This is done by
              default in most other shells.

              Note that splitting is applied to word in the  assignment  forms
              of  spec  before  the  assignment  to  name  is performed.  This
              affects the result of array assignments with the A flag.

       ${~spec}
              Turn on the GLOB_SUBST option for the evaluation of spec; if the
              `~'  is  doubled,  turn  it  off.   When this option is set, the
              string resulting from the expansion will  be  interpreted  as  a
              pattern anywhere that is possible, such as in filename expansion
              and filename generation and pattern-matching contexts  like  the
              right hand side of the `=' and `!=' operators in conditions.

              In  nested  substitutions, note that the effect of the ~ applies
              to  the  result  of  the  current  level  of  substitution.    A
              surrounding  pattern  operation  on  the  result  may cancel it.
              Hence,  for  example,  if  the  parameter  foo  is  set  to   *,
              ${~foo//\*/*.c}  is substituted by the pattern *.c, which may be
              expanded  by   filename   generation,   but   ${${~foo}//\*/*.c}
              substitutes  to  the  string  *.c,  which  will  not  be further
              expanded.

       If a  ${...}  type  parameter  expression  or  a  $(...)  type  command
       substitution  is  used in place of name above, it is expanded first and
       the result is used as if it  were  the  value  of  name.   Thus  it  is
       possible to perform nested operations:  ${${foo#head}%tail} substitutes
       the value of $foo with both `head' and `tail' deleted.  The  form  with
       $(...)  is  often  useful in combination with the flags described next;
       see the examples below.  Each name or  nested  ${...}  in  a  parameter
       expansion  may  also be followed by a subscript expression as described
       in Array Parameters in zshparam(1).

       Note that double quotes may appear around nested expressions, in  which
       case   only  the  part  inside  is  treated  as  quoted;  for  example,
       ${(f)"$(foo)"} quotes the result of $(foo), but  the  flag  `(f)'  (see
       below)  is  applied  using  the  rules  for  unquoted expansions.  Note
       further that quotes are themselves nested in this context; for example,
       in "${(@f)"$(foo)"}", there are two sets of quotes, one surrounding the
       whole expression, the  other  (redundant)  surrounding  the  $(foo)  as
       before.

   Parameter Expansion Flags
       If  the  opening  brace is directly followed by an opening parenthesis,
       the string up to the matching closing parenthesis will be  taken  as  a
       list  of  flags.   In  cases  where repeating a flag is meaningful, the
       repetitions need not be consecutive; for example, `(q%q%q)'  means  the
       same  thing  as  the  more readable `(%%qqq)'.  The following flags are
       supported:

       #      Evaluate the resulting words as numeric expressions  and  output
              the  characters  corresponding  to  the resulting integer.  Note
              that this form is entirely distinct from use of  the  #  without
              parentheses.

              If  the  MULTIBYTE  option is set and the number is greater than
              127 (i.e. not an ASCII character) it is  treated  as  a  Unicode
              character.

       %      Expand  all  % escapes in the resulting words in the same way as
              in prompts (see EXPANSION OF PROMPT SEQUENCES in zshmisc(1)). If
              this  flag  is given twice, full prompt expansion is done on the
              resulting words, depending on the setting of the PROMPT_PERCENT,
              PROMPT_SUBST and PROMPT_BANG options.

       @      In  double  quotes,  array elements are put into separate words.
              E.g.,  `"${(@)foo}"'  is   equivalent   to   `"${foo[@]}"'   and
              `"${(@)foo[1,2]}"'  is  the same as `"$foo[1]" "$foo[2]"'.  This
              is distinct from field splitting by the the f,  s  or  z  flags,
              which still applies within each array element.

       A      Create  an  array  parameter with `${...=...}', `${...:=...}' or
              `${...::=...}'.  If this flag is repeated (as in  `AA'),  create
              an  associative  array  parameter.   Assignment  is  made before
              sorting or padding.  The name part may be  a  subscripted  range
              for  ordinary  arrays;  the  word  part  must be converted to an
              array, for example by using `${(AA)=name=...}' to activate field
              splitting, when creating an associative array.

       a      Sort  in  array  index  order;  when  combined  with `O' sort in
              reverse  array  index  order.   Note  that  `a'   is   therefore
              equivalent  to  the  default but `Oa' is useful for obtaining an
              array's elements in reverse order.

       c      With ${#name}, count the total number of characters in an array,
              as if the elements were concatenated with spaces between them.

       C      Capitalize  the resulting words.  `Words' in this case refers to
              sequences    of    alphanumeric    characters    separated    by
              non-alphanumerics,   not   to   words  that  result  from  field
              splitting.

       D      Assume the string or  array  elements  contain  directories  and
              attempt  to  substitute the leading part of these by names.  The
              remainder of the path (the whole of it if the leading  part  was
              not  subsituted)  is then quoted so that the whole string can be
              used  as  a  shell  argument.   This  is  the  reverse  of   `~'
              substitution:  see the section FILENAME EXPANSION below.

       e      Perform parameter expansion, command substitution and arithmetic
              expansion on the result. Such expansions can be nested  but  too
              deep recursion may have unpredictable effects.

       f      Split  the  result  of  the  expansion  at  newlines.  This is a
              shorthand for `ps:\n:'.

       F      Join the words of arrays together using newline as a  separator.
              This is a shorthand for `pj:\n:'.

       i      Sort case-insensitively.  May be combined with `n' or `O'.

       k      If  name  refers  to  an  associative array, substitute the keys
              (element names) rather than the values of  the  elements.   Used
              with  subscripts  (including  ordinary arrays), force indices or
              keys to be substituted even if  the  subscript  form  refers  to
              values.   However,  this flag may not be combined with subscript
              ranges.

       L      Convert all letters in the result to lower case.

       n      Sort  decimal  integers  numerically;  if  the  first  differing
              characters  of  two  test  strings  are  not  digits, sorting is
              lexical.   Integers with more initial zeroes are  sorted  before
              those with fewer or none.  Hence the array `foo1 foo02 foo2 foo3
              foo20 foo23' is sorted into the order shown.   May  be  combined
              with `i' or `O'.

       o      Sort  the resulting words in ascending order; if this appears on
              its own the sorting is lexical and  case-sensitive  (unless  the
              locale renders it case-insensitive).  Sorting in ascending order
              is the default for other forms of sorting, so this is ignored if
              combined with `a', `i' or `n'.

       O      Sort  the  resulting words in descending order; `O' without `a',
              `i' or `n' sorts in reverse lexical order.  May be combined with
              `a', `i' or `n' to reverse the order of sorting.

       P      This forces the value of the parameter name to be interpreted as
              a further  parameter  name,  whose  value  will  be  used  where
              appropriate.  Note that flags set with one of the typeset family
              of commands (in particular case transformations) are not applied
              to the value of name used in this fashion.

              If  used  with  a  nested parameter or command substitution, the
              result of that will be taken as a parameter  name  in  the  same
              way.   For  example,  if  you  have `foo=bar' and `bar=baz', the
              strings ${(P)foo}, ${(P)${foo}}, and ${(P)$(echo bar)}  will  be
              expanded to `baz'.

       q      Quote  characters that are special to the shell in the resulting
              words with backslashes; unprintable or  invalid  characters  are
              quoted  using  the  $'\NNN'  form, with separate quotes for each
              octet.

              If this flag is given twice, the resulting words are  quoted  in
              single  quotes  and  if  it  is given three times, the words are
              quoted in double quotes; in these forms no special  handling  of
              unprintable  or invalid characters is attempted.  If the flag is
              given four times, the words are quoted in single quotes preceded
              by  a  $.  Note that in all three of these forms quoting is done
              unconditionally, even if  this  does  not  change  the  way  the
              resulting string would be interpreted by the shell.

              If a q- is given (only a single q may appear), a minimal form of
              single quoting is used that only quotes the string if needed  to
              protect  special characters.  Typically this form gives the most
              readable output.

       Q      Remove one level of quotes from the resulting words.

       t      Use a string describing the type  of  the  parameter  where  the
              value  of  the  parameter  would  usually  appear.  This  string
              consists of keywords  separated  by  hyphens  (`-').  The  first
              keyword  in the string describes the main type, it can be one of
              `scalar', `array',  `integer',  `float'  or  `association'.  The
              other keywords describe the type in more detail:

              local  for local parameters

              left   for left justified parameters

              right_blanks
                     for right justified parameters with leading blanks

              right_zeros
                     for right justified parameters with leading zeros

              lower  for parameters whose value is converted to all lower case
                     when it is expanded

              upper  for parameters whose value is converted to all upper case
                     when it is expanded

              readonly
                     for readonly parameters

              tag    for tagged parameters

              export for exported parameters

              unique for  arrays  which  keep  only  the  first  occurrence of
                     duplicated values

              hide   for parameters with the `hide' flag

              special
                     for special parameters defined by the shell

       u      Expand only the first occurrence of each unique word.

       U      Convert all letters in the result to upper case.

       v      Used with k, substitute (as two consecutive words) both the  key
              and  the  value  of  each  associative array element.  Used with
              subscripts, force values to be substituted even if the subscript
              form refers to indices or keys.

       V      Make any special characters in the resulting words visible.

       w      With  ${#name}, count words in arrays or strings; the s flag may
              be used to set a word delimiter.

       W      Similar to w  with  the  difference  that  empty  words  between
              repeated delimiters are also counted.

       X      With  this  flag,  parsing  errors occurring with the Q, e and #
              flags or the pattern matching forms  such  as  `${name#pattern}'
              are reported.  Without the flag, errors are silently ignored.

       z      Split the result of the expansion into words using shell parsing
              to find the words, i.e. taking into account any quoting  in  the
              value.   Comments  are  not  treated  specially  but as ordinary
              strings,   similar    to    interactive    shells    with    the
              INTERACTIVE_COMMENTS option unset.

              Note  that  this is done very late, as for the `(s)' flag. So to
              access single words  in  the  result,  one  has  to  use  nested
              expansions  as  in  `${${(z)foo}[2]}'.  Likewise,  to remove the
              quotes in the resulting words one would do: `${(Q)${(z)foo}}'.

       0      Split the result of the expansion on  null  bytes.   This  is  a
              shorthand for `ps:\0:'.

       The following flags (except p) are followed by one or more arguments as
       shown.  Any character, or the matching pairs `(...)', `{...}', `[...]',
       or  `<...>',  may  be  used in place of a colon as delimiters, but note
       that when a flag takes more  than  one  argument,  a  matched  pair  of
       delimiters must surround each argument.

       p      Recognize  the  same  escape  sequences  as the print builtin in
              string arguments to any of the flags described below that follow
              this argument.

       ~      Force  string  arguments  to  any of the flags below that follow
              within the parentheses to be treated as patterns.  Compare  with
              a  ~  outside  parentheses,  which forces the entire substituted
              string to be treated as a pattern.  Hence, for example,
              [[ "?" = ${(~j.|.)array} ]]
       with the EXTENDED_GLOB option  set  succeeds  if  and  only  if  $array
       contains the string `?' as an element.  The argument may be repeated to
       toggle the  behaviour;  its  effect  only  lasts  to  the  end  of  the
       parenthesised group.

       j:string:
              Join  the  words of arrays together using string as a separator.
              Note that this occurs before field splitting  by  the  s:string:
              flag or the SH_WORD_SPLIT option.

       l:expr::string1::string2:
              Pad  the  resulting  words  on  the  left.   Each  word  will be
              truncated if required and placed  in  a  field  expr  characters
              wide.

              The arguments :string1: and :string2: are optional; neither, the
              first, or both may be  given.   Note  that  the  same  pairs  of
              delimiters  must  be  used for each of the three arguments.  The
              space to the left will be filled with string1  (concatenated  as
              often  as  needed)  or  spaces if string1 is not given.  If both
              string1 and string2 are given, string2 is inserted once directly
              to the left of each word, truncated if necessary, before string1
              is used to produce any remaining padding.

              If the MULTIBYTE option is in effect, the flag  m  may  also  be
              given,  in which case widths will be used for the calculation of
              padding; otherwise individual multibyte characters  are  treated
              as occupying one unit of width.

              If  the  MULTIBYTE  option  is  not  in effect, each byte in the
              string is treated as occupying one unit of width.

              Control characters are always assumed to be one unit wide;  this
              allows  the  mechanism  to be used for generating repetitions of
              control characters.

       m      Only useful together with one of the flags l or r or with the  #
              length operator when the MULTIBYTE option is in effect.  Use the
              character width reported by the system in calculating  how  much
              of  the  string it occupies or the overall length of the string.
              Most printable characters have a  width  of  one  unit,  however
              certain  Asian  character  sets  and certain special effects use
              wider  characters;  combining  characters   have   zero   width.
              Non-printable  characters are arbitrarily counted as zero width;
              how they would actually be displayed will vary.

              If the m is repeated, the character either counts  zero  (if  it
              has zero width), else one.  For printable character strings this
              has the  effect  of  counting  the  number  of  glyphs  (visibly
              separate  characters),  except  for  the  case  where  combining
              characters themselves  have  non-zero  width  (true  in  certain
              alphabets).

       r:expr::string1::string2:
              As  l,  but  pad  the  words  on  the  right  and insert string2
              immediately to the right of the string to be padded.

              Left and right padding may be used together.  In this  case  the
              strategy  is  to  apply  left padding to the first half width of
              each of the resulting words, and right  padding  to  the  second
              half.   If  the  string  to  be  padded  has odd width the extra
              padding is applied on the left.

       s:string:
              Force field splitting at the  separator  string.   Note  that  a
              string  of  two  or  more characters means that all of them must
              match in sequence; this differs from the  treatment  of  two  or
              more  characters  in the IFS parameter.  See also the = flag and
              the SH_WORD_SPLIT option.

              For historical reasons, the usual  behaviour  that  empty  array
              elements  are  retained  inside  double  quotes  is disabled for
              arrays generated by splitting; hence the following:

                     line="one::three"
                     print -l "${(s.:.)line}"

              produces two lines of output for one and three  and  elides  the
              empty  field.  To override this behaviour, supply the "(@)" flag
              as well, i.e.  "${(@s.:.)line}".

       Z:opts:
              As z but  takes  a  combination  of  option  letters  between  a
              following  pair of delimiter characters.  (Z+c+) causes comments
              to be parsed  as  a  string  and  retained;  any  field  in  the
              resulting  array beginning with an unquoted comment character is
              a comment.  (Z+C+) causes comments to  be  parsed  and  removed.
              The  rule  for  comments  is  standard:  anything between a word
              starting with the third character of $HISTCHARS, default  #,  up
              to  the  next  newline  is  a  comment.   (Z+n+) causes unquoted
              newlines to be treated as ordinary  whitespace,  else  they  are
              treated  as  if  they are shell code delimiters and converted to
              semicolons.

       _:flags:
              The underscore (_) flag is reserved for future use.  As of  this
              revision of zsh, there are no valid flags; anything following an
              underscore, other than an empty pair of delimiters,  is  treated
              as an error, and the flag itself has no effect.

       The  following  flags  are meaningful with the ${...#...} or ${...%...}
       forms.  The S and I flags may also be used with the ${.../...} forms.

       S      Search substrings as well as beginnings or ends;  with  #  start
              from  the beginning and with % start from the end of the string.
              With  substitution  via  ${.../...}  or  ${...//...},  specifies
              non-greedy  matching,  i.e.  that  the  shortest  instead of the
              longest match should be replaced.

       I:expr:
              Search the exprth match (where  expr  evaluates  to  a  number).
              This only applies when searching for substrings, either with the
              S  flag,  or  with  ${.../...}  (only  the   exprth   match   is
              substituted)  or ${...//...} (all matches from the exprth on are
              substituted).  The default is to take the first match.

              The exprth match is counted such that there  is  either  one  or
              zero matches from each starting position in the string, although
              for   global   substitution   matches    overlapping    previous
              replacements  are  ignored.  With the ${...%...} and ${...%%...}
              forms, the starting position for the match moves backwards  from
              the  end  as  the index increases, while with the other forms it
              moves forward from the start.

              Hence with the string
                     which switch is the right switch for Ipswich?
              substitutions of the form ${(SI:N:)string#w*ch} as  N  increases
              from  1  will  match  and  remove  `which', `witch', `witch' and
              `wich'; the form using `##' will match and remove `which  switch
              is the right switch for Ipswich', `witch is the right switch for
              Ipswich', `witch for Ipswich' and `wich'.  The  form  using  `%'
              will  remove  the same matches as for `#', but in reverse order,
              and the form using `%%' will remove the same matches as for `##'
              in reverse order.

       B      Include the index of the beginning of the match in the result.

       E      Include the index of the end of the match in the result.

       M      Include the matched portion in the result.

       N      Include the length of the match in the result.

       R      Include the unmatched portion in the result (the Rest).

   Rules
       Here  is  a  summary  of  the rules for substitution; this assumes that
       braces  are  present  around  the  substitution,  i.e.  ${...}.    Some
       particular  examples  are  given  below.  Note that the Zsh Development
       Group accepts no responsibility for any brain damage  which  may  occur
       during the reading of the following rules.

       1. Nested Substitution
              If  multiple  nested  ${...}  forms are present, substitution is
              performed  from  the  inside  outwards.   At  each  level,   the
              substitution  takes  account  of  whether the current value is a
              scalar or an array, whether the whole substitution is in  double
              quotes,  and  what  flags  are  supplied to the current level of
              substitution, just  as  if  the  nested  substitution  were  the
              outermost.   The  flags  are  not  propagated  up  to  enclosing
              substitutions; the nested  substitution  will  return  either  a
              scalar or an array as determined by the flags, possibly adjusted
              for  quoting.   All  the  following  steps  take   place   where
              applicable at all levels of substitution.  Note that, unless the
              `(P)' flag is  present,  the  flags  and  any  subscripts  apply
              directly  to  the value of the nested substitution; for example,
              the expansion ${${foo}} behaves exactly the same as ${foo}.

              At each nested level  of  substitution,  the  substituted  words
              undergo all forms of single-word substitution (i.e. not filename
              generation),   including   command   substitution,    arithmetic
              expansion  and filename expansion (i.e. leading ~ and =).  Thus,
              for example, ${${:-=cat}:h} expands to the directory  where  the
              cat  program  resides.   (Explanation: the internal substitution
              has no parameter but a default value =cat, which is expanded  by
              filename  expansion  to a full path; the outer substitution then
              applies the modifier :h and takes  the  directory  part  of  the
              path.)

       2. Internal Parameter Flags
              Any  parameter  flags  set  by  one  of  the  typeset  family of
              commands, in particular the L, R, Z, u and l flags  for  padding
              and capitalization, are applied directly to the parameter value.

       3. Parameter Subscripting
              If the value is a raw parameter reference with a subscript, such
              as ${var[3]}, the effect of subscripting is applied directly  to
              the   parameter.    Subscripts  are  evaluated  left  to  right;
              subsequent subscripts apply to the scalar or array value yielded
              by   the   previous   subscript.   Thus  if  var  is  an  array,
              ${var[1][2]} is the second character  of  the  first  word,  but
              ${var[2,4][2]}  is the entire third word (the second word of the
              range of words two through four of  the  original  array).   Any
              number of subscripts may appear.

       4. Parameter Name Replacement
              The  effect  of any (P) flag, which treats the value so far as a
              parameter name and replaces it with the corresponding value,  is
              applied.

       5. Double-Quoted Joining
              If   the   value  after  this  process  is  an  array,  and  the
              substitution appears in  double  quotes,  and  no  (@)  flag  is
              present  at the current level, the words of the value are joined
              with the first character of the parameter  $IFS,  by  default  a
              space,  between each word (single word arrays are not modified).
              If the (j) flag is present, that is used for joining instead  of
              $IFS.

       6. Nested Subscripting
              Any  remaining  subscripts  (i.e.  of a nested substitution) are
              evaluated at this point, based on whether the value is an  array
              or  a scalar.  As with 3., multiple subscripts can appear.  Note
              that ${foo[2,4][2]} is thus equivalent to ${${foo[2,4]}[2]}  and
              also  to "${${(@)foo[2,4]}[2]}" (the nested substitution returns
              an array in both cases), but  not  to  "${${foo[2,4]}[2]}"  (the
              nested substitution returns a scalar because of the quotes).

       7. Modifiers
              Any  modifiers,  as  specified  by  a  trailing  `#',  `%',  `/'
              (possibly doubled) or by a set of modifiers  of  the  form  :...
              (see   the   section   `Modifiers'   in   the  section  `History
              Expansion'), are applied to the  words  of  the  value  at  this
              level.

       8. Character evaluation
              Any   (#)   flag  is  applied,  evaluating  the  result  so  far
              numerically as a character.

       9. Length
              Any initial # modifier, i.e. in the form  ${#var},  is  used  to
              evaluate the length of the expression so far.

       10. Forced Joining
              If  the  `(j)'  flag is present, or no `(j)' flag is present but
              the string is to be split as given by  rules  16.  or  17.,  and
              joining  did  not  take place at step 5., any words in the value
              are  joined  together  using  the  given  string  or  the  first
              character  of $IFS if none.  Note that the `(F)' flag implicitly
              supplies a string for joining in this manner.

       11. Case modification
              Any case modification from one of the flags (L), (U) or  (C)  is
              applied.

       12. Prompt evaluation
              Any  prompt-style  formatting  from  the  (%) family of flags is
              applied.

       13. Quote application
              Any quoting or unquoting using (q) and (Q) and related flags  is
              applied.

       14. Directory naming
              Any directory name substitution using (D) flag is applied.

       15. Visibility enhancment
              Any  modifications to make characters visible using the (V) flag
              are applied.

       16. Forced Splitting
              If one of the `(s)', `(f)' or `(z)' flags are  present,  or  the
              `='  specifier  was present (e.g. ${=var}), the word is split on
              occurrences of the specified string, or (for = with  neither  of
              the two flags present) any of the characters in $IFS.

       17. Shell Word Splitting
              If  no `(s)', `(f)' or `=' was given, but the word is not quoted
              and the option SH_WORD_SPLIT  is  set,  the  word  is  split  on
              occurrences  of  any of the characters in $IFS.  Note this step,
              too, takes place at all levels of a nested substitution.

       18. Uniqueness
              If the result is an  array  and  the  `(u)'  flag  was  present,
              duplicate elements are removed from the array.

       19. Ordering
              If  the  result  is still an array and one of the `(o)' or `(O)'
              flags was present, the array is reordered.

       20. Re-Evaluation
              Any `(e)' flag is  applied  to  the  value,  forcing  it  to  be
              re-examined  for  new  parameter  substitutions,  but  also  for
              command and arithmetic substitutions.

       21. Padding
              Any padding of the value by the `(l.fill.)' or `(r.fill.)' flags
              is applied.

       22. Semantic Joining
              In  contexts where expansion semantics requires a single word to
              result, all words are rejoined with the first character  of  IFS
              between.   So  in  `${(P)${(f)lines}}'  the value of ${lines} is
              split at newlines, but then must be joined again  before  the  P
              flag can be applied.

              If a single word is not required, this rule is skipped.

       23. Empty argument removal
              If  the  substitution  does  not  appear  in  double quotes, any
              resulting zero-length argument, whether  from  a  scalar  or  an
              element  of  an  array,  is  elided  from  the list of arguments
              inserted into the command line.

              Strictly speaking, the removal happens later as the same happens
              with  other  forms  of  substitution;  the point to note here is
              simply  that  it  occurs  after  any  of  the  above   parameter
              operations.

   Examples
       The  flag  f  is  useful  to split a double-quoted substitution line by
       line.  For example, ${(f)"$(<file)"} substitutes the contents  of  file
       divided  so  that  each  line  is  an  element  of the resulting array.
       Compare this with the effect of $(<file) alone, which divides the  file
       up  by  words, or the same inside double quotes, which makes the entire
       content of the file a single string.

       The following illustrates the rules for  nested  parameter  expansions.
       Suppose that $foo contains the array (bar baz):

       "${(@)${foo}[1]}"
              This  produces  the  result  b.   First,  the inner substitution
              "${foo}", which has no array (@) flag, produces  a  single  word
              result "bar baz".  The outer substitution "${(@)...[1]}" detects
              that this is a scalar, so that  (despite  the  `(@)'  flag)  the
              subscript picks the first character.

       "${${(@)foo}[1]}"
              This  produces  the  result  `bar'.   In  this  case,  the inner
              substitution "${(@)foo}" produces the array  `(bar  baz)'.   The
              outer substitution "${...[1]}" detects that this is an array and
              picks the first word.   This  is  similar  to  the  simple  case
              "${foo[1]}".

       As an example of the rules for word splitting and joining, suppose $foo
       contains the array `(ax1 bx1)'.  Then

       ${(s/x/)foo}
              produces the words `a', `1 b' and `1'.

       ${(j/x/s/x/)foo}
              produces `a', `1', `b' and `1'.

       ${(s/x/)foo%%1*}
              produces `a' and ` b' (note the extra space).   As  substitution
              occurs  before either joining or splitting, the operation  first
              generates the modified array (ax bx), which is  joined  to  give
              "ax  bx",  and  then  split to give `a', ` b' and `'.  The final
              empty string will then be elided, as it is not in double quotes.

COMMAND SUBSTITUTION

       A command enclosed in parentheses  preceded  by  a  dollar  sign,  like
       `$(...)',  or quoted with grave accents, like ``...`', is replaced with
       its standard output,  with  any  trailing  newlines  deleted.   If  the
       substitution  is  not  enclosed  in double quotes, the output is broken
       into words using the IFS parameter.  The substitution `$(cat foo)'  may
       be replaced by the equivalent but faster `$(<foo)'.  In either case, if
       the option GLOB_SUBST is set,  the  output  is  eligible  for  filename
       generation.

ARITHMETIC EXPANSION

       A  string  of  the  form `$[exp]' or `$((exp))' is substituted with the
       value of the arithmetic expression exp.  exp is subjected to  parameter
       expansion,  command  substitution and arithmetic expansion before it is
       evaluated.  See the section `Arithmetic Evaluation'.

BRACE EXPANSION

       A string of the form `foo{xx,yy,zz}bar' is expanded to  the  individual
       words  `fooxxbar',  `fooyybar'  and `foozzbar'.  Left-to-right order is
       preserved.  This construct may be nested.   Commas  may  be  quoted  in
       order to include them literally in a word.

       An  expression of the form `{n1..n2}', where n1 and n2 are integers, is
       expanded to every number between n1 and n2 inclusive.  If either number
       begins  with  a  zero,  all  the  resulting numbers will be padded with
       leading zeroes to that minimum width, but for negative  numbers  the  -
       character  is  also  included  in  the  width.   If  the numbers are in
       decreasing order the resulting sequence  will  also  be  in  decreasing
       order.

       An  expression  of  the  form  `{n1..n2..n3}', where n1, n2, and n3 are
       integers, is expanded as above, but only  every  n3th  number  starting
       from n1 is output.  If n3 is negative the numbers are output in reverse
       order, this is slightly different from simply swapping n1 and n2 in the
       case  that  the  step n3 doesn't evenly divide the range.  Zero padding
       can be specified in any of the three  numbers,  specifying  it  in  the
       third  can  be  useful to pad for example `{-99..100..01}' which is not
       possible to specify by putting a 0 on either of the first  two  numbers
       (i.e. pad to two characters).

       If  a  brace  expression  matches  none  of the above forms, it is left
       unchanged, unless the option  BRACE_CCL  (an  abbreviation  for  `brace
       character  class')  is  set.  In that case, it is expanded to a list of
       the individual characters between the braces sorted into the  order  of
       the characters in the ASCII character set (multibyte characters are not
       currently handled).  The syntax is similar to  a  [...]  expression  in
       filename  generation:  `-'  is  treated  specially to denote a range of
       characters, but `^' or `!' as the first character is treated  normally.
       For  example, `{abcdef0-9}' expands to 16 words 0 1 2 3 4 5 6 7 8 9 a b
       c d e f.

       Note  that  brace  expansion  is  not  part  of   filename   generation
       (globbing);  an  expression  such  as  */{foo,bar}  is  split  into two
       separate words */foo and */bar before filename generation takes  place.
       In  particular,  note that this is liable to produce a `no match' error
       if either of the  two  expressions  does  not  match;  this  is  to  be
       contrasted  with  */(foo|bar), which is treated as a single pattern but
       otherwise has similar effects.

       To combine brace expansion with array expansion, see the ${^spec}  form
       described in the section Parameter Expansion above.

FILENAME EXPANSION

       Each  word  is checked to see if it begins with an unquoted `~'.  If it
       does, then the word up to a `/', or the end of the word if there is  no
       `/',  is  checked  to  see  if it can be substituted in one of the ways
       described here.  If so, then  the  `~'  and  the  checked  portion  are
       replaced with the appropriate substitute value.

       A `~' by itself is replaced by the value of $HOME.  A `~' followed by a
       `+' or a `-' is replaced by  current  or  previous  working  directory,
       respectively.

       A  `~'  followed  by  a  number  is  replaced  by the directory at that
       position in the directory stack.  `~0' is equivalent to `~+', and  `~1'
       is  the top of the stack.  `~+' followed by a number is replaced by the
       directory at that position in the directory stack.  `~+0' is equivalent
       to  `~+', and `~+1' is the top of the stack.  `~-' followed by a number
       is replaced by the directory that many positions from the bottom of the
       stack.   `~-0'  is  the  bottom  of  the stack.  The PUSHD_MINUS option
       exchanges the effects of `~+' and `~-' where they  are  followed  by  a
       number.

   Dynamic named directories
       The  feature  described  here  is  only available if the shell function
       zsh_directory_name exists.

       A `~' followed by a  string  namstr  in  unquoted  square  brackets  is
       treated  specially  as  a  dynamic directory name.  Note that the first
       unquoted closing square bracket always terminates  namstr.   The  shell
       function  is  passed two arguments: the string n (for name) and namstr.
       It should either set the array reply to a single element which  is  the
       directory  corresponding  to the name and return status zero (executing
       an assignment as the last  statement  is  usually  sufficient),  or  it
       should return status non-zero.  In the former case the element of reply
       is used as the directory; in the latter case the substitution is deemed
       to have failed and NOMATCH handling is applied if the option is set.

       The  function zsh_directory_name is also used to see if a directory can
       be turned into a name, for example when printing the directory stack or
       when  expanding %~ in prompts.  In this case the function is passed two
       arguments: the string d (for directory) and the candidate  for  dynamic
       naming.   The  function  should  either  return non-zero status, if the
       directory cannot be named by the function, or it should set  the  array
       reply to consist of two elements: the first is the dynamic name for the
       directory (as would appear within `~[...]'),  and  the  second  is  the
       prefix  length  of  the  directory to be replaced.  For example, if the
       trial directory  is  /home/myname/src/zsh  and  the  dynamic  name  for
       /home/myname/src (which has 16 characters) is s, then the function sets

              reply=(s 16)

       The  directory  name so returned is compared with possible static names
       for parts of the directory path, as described below; it is used if  the
       prefix  length  matched (16 in the example) is longer than that matched
       by any static name.

       The completion system calls `zsh_directory_name c' in order to complete
       dynamic  names for directories.  The code for this should be as for any
       other completion function as described in zshcompsys(1).

       As a working example, here is a function that expands any dynamic names
       beginning  with  the string p: to directories below /home/pws/perforce.
       In this simple case a static name for the directory would  be  just  as
       effective.

              zsh_directory_name() {
                emulate -L zsh
                setopt extendedglob
                local -a match mbegin mend
                if [[ $1 = d ]]; then
                  # turn the directory into a name
                  if [[ $2 = (#b)(/home/pws/perforce/)([^/]##)* ]]; then
                    typeset -ga reply
                    reply=(p:$match[2] $(( ${#match[1]} + ${#match[2]} )) )
                  else
                    return 1
                  fi
                elif [[ $1 = n ]]; then
                  # turn the name into a directory
                  [[ $2 != (#b)p:(?*) ]] && return 1
                  typeset -ga reply
                  reply=(/home/pws/perforce/$match[1])
                elif [[ $1 = c ]]; then
                  # complete names
                  local expl
                  local -a dirs
                  dirs=(/home/pws/perforce/*(/:t))
                  dirs=(p:${^dirs})
                  _wanted dynamic-dirs expl 'dynamic directory' compadd -S\] -a dirs
                  return
                else
                  return 1
                fi
                return 0
              }

   Static named directories
       A `~' followed by anything not already covered consisting of any number
       of alphanumeric characters or underscore (`_'), hyphen  (`-'),  or  dot
       (`.')  is  looked up as a named directory, and replaced by the value of
       that named directory if found.  Named directories  are  typically  home
       directories  for  users on the system.  They may also be defined if the
       text after the `~' is the name of a string shell parameter whose  value
       begins with a `/'.  Note that trailing slashes will be removed from the
       path to the directory (though the original parameter is not modified).

       It is also possible to define directory names using the  -d  option  to
       the hash builtin.

       In  certain  circumstances  (in  prompts, for instance), when the shell
       prints a path, the path is checked to see if it has a  named  directory
       as  its  prefix.  If so, then the prefix portion is replaced with a `~'
       followed by the name of the directory.  The shortest way  of  referring
       to  the  directory is used, with ties broken in favour of using a named
       directory, except when the directory is / itself.  The parameters  $PWD
       and $OLDPWD are never abbreviated in this fashion.

   `=' expansion
       If a word begins with an unquoted `=' and the EQUALS option is set, the
       remainder of the word is taken as the name of a command.  If a  command
       exists  by  that name, the word is replaced by the full pathname of the
       command.

   Notes
       Filename expansion is performed on the right hand side of  a  parameter
       assignment,  including  those  appearing  after commands of the typeset
       family.  In this case, the  right  hand  side  will  be  treated  as  a
       colon-separated list in the manner of the PATH parameter, so that a `~'
       or an `='  following  a  `:'  is  eligible  for  expansion.   All  such
       behaviour  can  be  disabled  by quoting the `~', the `=', or the whole
       expression (but not simply  the  colon);  the  EQUALS  option  is  also
       respected.

       If  the option MAGIC_EQUAL_SUBST is set, any unquoted shell argument in
       the form `identifier=expression' becomes eligible for file expansion as
       described  in  the  previous  paragraph.   Quoting  the  first `=' also
       inhibits this.

FILENAME GENERATION

       If a word contains an unquoted instance of one of the  characters  `*',
       `(',  `|',  `<',  `[', or `?', it is regarded as a pattern for filename
       generation, unless the GLOB option  is  unset.   If  the  EXTENDED_GLOB
       option  is  set,  the  `^'  and  `#'  characters also denote a pattern;
       otherwise they are not treated specially by the shell.

       The word is replaced with a list of sorted  filenames  that  match  the
       pattern.   If  no  matching  pattern is found, the shell gives an error
       message, unless the NULL_GLOB option is set, in which case the word  is
       deleted;  or unless the NOMATCH option is unset, in which case the word
       is left unchanged.

       In filename generation, the character `/' must be  matched  explicitly;
       also, a `.' must be matched explicitly at the beginning of a pattern or
       after  a  `/',  unless  the  GLOB_DOTS  option  is  set.   No  filename
       generation  pattern  matches the files `.' or `..'.  In other instances
       of pattern matching, the `/' and `.' are not treated specially.

   Glob Operators
       *      Matches any string, including the null string.

       ?      Matches any character.

       [...]  Matches any of the enclosed characters.   Ranges  of  characters
              can  be  specified by separating two characters by a `-'.  A `-'
              or `]' may be matched by including it as the first character  in
              the  list.   There are also several named classes of characters,
              in the form `[:name:]' with the following meanings.   The  first
              set  use the macros provided by the operating system to test for
              the given character combinations,  including  any  modifications
              due to local language settings, see ctype(3):

              [:alnum:]
                     The character is alphanumeric

              [:alpha:]
                     The character is alphabetic

              [:ascii:]
                     The  character  is 7-bit, i.e. is a single-byte character
                     without the top bit set.

              [:blank:]
                     The character is either space or tab

              [:cntrl:]
                     The character is a control character

              [:digit:]
                     The character is a decimal digit

              [:graph:]
                     The  character  is  a  printable  character  other   than
                     whitespace

              [:lower:]
                     The character is a lowercase letter

              [:print:]
                     The character is printable

              [:punct:]
                     The  character  is printable but neither alphanumeric nor
                     whitespace

              [:space:]
                     The character is whitespace

              [:upper:]
                     The character is an uppercase letter

              [:xdigit:]
                     The character is a hexadecimal digit

              Another set of named classes is handled internally by the  shell
              and is not sensitive to the locale:

              [:IDENT:]
                     The  character  is  allowed  to  form  part  of  a  shell
                     identifier, such as a parameter name

              [:IFS:]
                     The character is used as an input field  separator,  i.e.
                     is contained in the IFS parameter

              [:IFSSPACE:]
                     The  character  is  an IFS white space character; see the
                     documentation for IFS in the zshparam(1) manual page.

              [:WORD:]
                     The character is treated as part of a word; this test  is
                     sensitive to the value of the WORDCHARS parameter

              Note  that the square brackets are additional to those enclosing
              the  whole  set  of  characters,  so  to  test  for   a   single
              alphanumeric  character you need `[[:alnum:]]'.  Named character
              sets can be used alongside other types, e.g. `[[:alpha:]0-9]'.

       [^...]
       [!...] Like [...], except that it matches any character which is not in
              the given set.

       <[x]-[y]>
              Matches  any  number  in the range x to y, inclusive.  Either of
              the numbers may be omitted to make the range  open-ended;  hence
              `<->' matches any number.  To match individual digits, the [...]
              form is more efficient.

              Be careful when using other wildcards adjacent  to  patterns  of
              this  form;  for  example, <0-9>* will actually match any number
              whatsoever at the start of the string, since  the  `<0-9>'  will
              match  the first digit, and the `*' will match any others.  This
              is a  trap  for  the  unwary,  but  is  in  fact  an  inevitable
              consequence  of  the rule that the longest possible match always
              succeeds.  Expressions such as `<0-9>[^[:digit:]]*' can be  used
              instead.

       (...)  Matches  the  enclosed  pattern.  This is used for grouping.  If
              the KSH_GLOB option is set, then a `@', `*',  `+',  `?'  or  `!'
              immediately  preceding the `(' is treated specially, as detailed
              below. The option SH_GLOB prevents bare parentheses  from  being
              used in this way, though the KSH_GLOB option is still available.

              Note  that  grouping cannot extend over multiple directories: it
              is an error to have a `/' within a group (this only applies  for
              patterns  used in filename generation).  There is one exception:
              a group of the form (pat/)# appearing as a complete path segment
              can match a sequence of directories.  For example, foo/(a*/)#bar
              matches foo/bar, foo/any/bar, foo/any/anyother/bar, and so on.

       x|y    Matches either x or y.  This operator has lower precedence  than
              any  other.   The  `|'  character must be within parentheses, to
              avoid interpretation as a pipeline.

       ^x     (Requires EXTENDED_GLOB to be set.)  Matches anything except the
              pattern x.  This has a higher precedence than `/', so `^foo/bar'
              will search directories in `.' except `./foo' for a  file  named
              `bar'.

       x~y    (Requires EXTENDED_GLOB to be set.)  Match anything that matches
              the pattern x but does not match y.  This has  lower  precedence
              than  any  operator except `|', so `*/*~foo/bar' will search for
              all files in all directories in `.'  and then exclude  `foo/bar'
              if there was such a match.  Multiple patterns can be excluded by
              `foo~bar~baz'.  In the exclusion pattern (y), `/'  and  `.'  are
              not treated specially the way they usually are in globbing.

       x#     (Requires  EXTENDED_GLOB  to  be  set.)   Matches  zero  or more
              occurrences  of  the  pattern  x.   This   operator   has   high
              precedence; `12#' is equivalent to `1(2#)', rather than `(12)#'.
              It is an error for an unquoted `#'  to  follow  something  which
              cannot  be  repeated;  this  includes an empty string, a pattern
              already followed by `##', or parentheses when part of a KSH_GLOB
              pattern  (for example, `!(foo)#' is invalid and must be replaced
              by `*(!(foo))').

       x##    (Requires  EXTENDED_GLOB  to  be  set.)   Matches  one  or  more
              occurrences   of   the   pattern  x.   This  operator  has  high
              precedence;  `12##'  is  equivalent  to  `1(2##)',  rather  than
              `(12)##'.   No  more  than  two active `#' characters may appear
              together.  (Note the potential clash with glob qualifiers in the
              form `1(2##)' which should therefore be avoided.)

   ksh-like Glob Operators
       If  the  KSH_GLOB  option  is  set,  the  effects of parentheses can be
       modified by a preceding `@', `*', `+', `?' or `!'.  This character need
       not be unquoted to have special effects, but the `(' must be.

       @(...) Match the pattern in the parentheses.  (Like `(...)'.)

       *(...) Match any number of occurrences.  (Like `(...)#'.)

       +(...) Match at least one occurrence.  (Like `(...)##'.)

       ?(...) Match zero or one occurrence.  (Like `(|...)'.)

       !(...) Match   anything  but  the  expression  in  parentheses.   (Like
              `(^(...))'.)

   Precedence
       The precedence of the operators given above is (highest) `^', `/', `~',
       `|'  (lowest);  the remaining operators are simply treated from left to
       right as part of a string, with `#' and `##' applying to  the  shortest
       possible  preceding unit (i.e. a character, `?', `[...]', `<...>', or a
       parenthesised expression).   As  mentioned  above,  a  `/'  used  as  a
       directory separator may not appear inside parentheses, while a `|' must
       do so; in patterns used in other contexts than filename generation (for
       example,  in  case statements and tests within `[[...]]'), a `/' is not
       special; and `/' is also not special  after  a  `~'  appearing  outside
       parentheses in a filename pattern.

   Globbing Flags
       There  are various flags which affect any text to their right up to the
       end of the enclosing group or to the end of the pattern;  they  require
       the  EXTENDED_GLOB  option. All take the form (#X) where X may have one
       of the following forms:

       i      Case insensitive:  upper or lower case characters in the pattern
              match upper or lower case characters.

       l      Lower  case  characters in the pattern match upper or lower case
              characters; upper case characters  in  the  pattern  still  only
              match upper case characters.

       I      Case  sensitive:  locally negates the effect of i or l from that
              point on.

       b      Activate backreferences for parenthesised groups in the pattern;
              this  does not work in filename generation.  When a pattern with
              a set of active parentheses is matched, the strings  matched  by
              the  groups  are  stored in the array $match, the indices of the
              beginning of the matched parentheses in the array  $mbegin,  and
              the  indices  of  the  end  in  the  array $mend, with the first
              element of each array corresponding to the  first  parenthesised
              group, and so on.  These arrays are not otherwise special to the
              shell.  The indices use the same convention  as  does  parameter
              substitution,  so that elements of $mend and $mbegin may be used
              in subscripts; the KSH_ARRAYS  option  is  respected.   Sets  of
              globbing flags are not considered parenthesised groups; only the
              first nine active parentheses can be referenced.

              For example,

                     foo="a string with a message"
                     if [[ $foo = (a|an)' '(#b)(*)' '* ]]; then
                       print ${foo[$mbegin[1],$mend[1]]}
                     fi

              prints `string with a'.  Note  that  the  first  parenthesis  is
              before the (#b) and does not create a backreference.

              Backreferences  work  with  all  forms of pattern matching other
              than filename generation, but note that when performing  matches
              on  an  entire  array,  such  as  ${array#pattern},  or a global
              substitution, such as ${param//pat/repl}, only the data for  the
              last   match   remains   available.    In  the  case  of  global
              replacements this may still be useful.  See the example for  the
              m flag below.

              The  numbering  of  backreferences strictly follows the order of
              the opening parentheses  from  left  to  right  in  the  pattern
              string,  although  sets of parentheses may be nested.  There are
              special rules for parentheses followed by `#' or `##'.  Only the
              last match of the parenthesis is remembered: for example, in `[[
              abab =  (#b)([ab])#  ]]',  only  the  final  `b'  is  stored  in
              match[1].   Thus extra parentheses may be necessary to match the
              complete segment: for example, use  `X((ab|cd)#)Y'  to  match  a
              whole  string  of either `ab' or `cd' between `X' and `Y', using
              the value of $match[1] rather than $match[2].

              If the match fails none of the parameters is altered, so in some
              cases  it  may  be  necessary to initialise them beforehand.  If
              some of the backreferences fail to match  --  which  happens  if
              they are in an alternate branch which fails to match, or if they
              are followed by # and matched zero times  --  then  the  matched
              string is set to the empty string, and the start and end indices
              are set to -1.

              Pattern matching with backreferences  is  slightly  slower  than
              without.

       B      Deactivate  backreferences,  negating  the  effect of the b flag
              from that point on.

       cN,M   The flag (#cN,M) can be used anywhere that the # or ## operators
              can be used; it cannot be combined with other globbing flags and
              a bad pattern error occurs if it is misplaced.  It is equivalent
              to   the  form  {N,M}  in  regular  expressions.   The  previous
              character or group is required to match between N and  M  times,
              inclusive.  The form (#cN) requires exactly N matches; (#c,M) is
              equivalent to specifying N as 0; (#cN,) specifies that there  is
              no maximum limit on the number of matches.

       m      Set  references to the match data for the entire string matched;
              this is similar to backreferencing and does not work in filename
              generation.   The  flag  must  be  in  effect  at the end of the
              pattern, i.e. not local  to  a  group.  The  parameters  $MATCH,
              $MBEGIN  and  $MEND will be set to the string matched and to the
              indices of the beginning and end of  the  string,  respectively.
              This is most useful in parameter substitutions, as otherwise the
              string matched is obvious.

              For example,

                     arr=(veldt jynx grimps waqf zho buck)
                     print ${arr//(#m)[aeiou]/${(U)MATCH}}

              forces  all  the  matches  (i.e.  all  vowels)  into  uppercase,
              printing `vEldt jynx grImps wAqf zhO bUck'.

              Unlike backreferences, there is no speed penalty for using match
              references, other than the extra substitutions required for  the
              replacement strings in cases such as the example shown.

       M      Deactivate the m flag, hence no references to match data will be
              created.

       anum   Approximate matching: num  errors  are  allowed  in  the  string
              matched by the pattern.  The rules for this are described in the
              next subsection.

       s, e   Unlike the other flags, these have only a local effect, and each
              must  appear  on  its own:  `(#s)' and `(#e)' are the only valid
              forms.  The `(#s)' flag succeeds only at the start of  the  test
              string, and the `(#e)' flag succeeds only at the end of the test
              string; they correspond to  `^'  and  `$'  in  standard  regular
              expressions.   They  are  useful  for  matching path segments in
              patterns other than those in  filename  generation  (where  path
              segments  are  in  any  case  treated separately).  For example,
              `*((#s)|/)test((#e)|/)*' matches a path segment `test' in any of
              the   following   strings:   test,  test/at/start,  at/end/test,
              in/test/middle.

              Another  use  is  in   parameter   substitution;   for   example
              `${array/(#s)A*Z(#e)}'  will  remove  only  elements of an array
              which match the complete pattern `A*Z'.  There are other ways of
              performing many operations of this type, however the combination
              of the substitution operations `/' and `//' with the `(#s)'  and
              `(#e)' flags provides a single simple and memorable method.

              Note that assertions of the form `(^(#s))' also work, i.e. match
              anywhere except at  the  start  of  the  string,  although  this
              actually  means  `anything  except  a zero-length portion at the
              start of the string'; you need to use  `(""~(#s))'  to  match  a
              zero-length portion of the string not at the start.

       q      A  `q'  and  everything  up  to  the  closing parenthesis of the
              globbing flags are ignored by the pattern matching  code.   This
              is  intended  to  support the use of glob qualifiers, see below.
              The result is that the pattern `(#b)(*).c(#q.)' can be used both
              for  globbing  and for matching against a string.  In the former
              case, the `(#q.)' will be treated as a glob  qualifier  and  the
              `(#b)'  will  not be useful, while in the latter case the `(#b)'
              is useful for backreferences and the `(#q.)'  will  be  ignored.
              Note  that  colon  modifiers in the glob qualifiers are also not
              applied in ordinary pattern matching.

       u      Respect the  current  locale  in  determining  the  presence  of
              multibyte  characters  in  a  pattern,  provided  the  shell was
              compiled with MULTIBYTE_SUPPORT.  This overrides  the  MULTIBYTE
              option; the default behaviour is taken from the option.  Compare
              U.  (Mnemonic: typically multibyte characters are  from  Unicode
              in the UTF-8 encoding, although any extension of ASCII supported
              by the system library may be used.)

       U      All characters are considered to be a  single  byte  long.   The
              opposite of u.  This overrides the MULTIBYTE option.

       For  example,  the  test  string  fooxx  can  be matched by the pattern
       (#i)FOOXX, but not by (#l)FOOXX,  (#i)FOO(#I)XX  or  ((#i)FOOX)X.   The
       string  (#ia2)readme specifies case-insensitive matching of readme with
       up to two errors.

       When using the ksh syntax for grouping both KSH_GLOB and  EXTENDED_GLOB
       must  be  set  and  the left parenthesis should be preceded by @.  Note
       also that the flags do not affect letters inside [...] groups, in other
       words  (#i)[a-z]  still  matches only lowercase letters.  Finally, note
       that when examining whole paths case-insensitively every directory must
       be  searched  for  all files which match, so that a pattern of the form
       (#i)/foo/bar/... is potentially slow.

   Approximate Matching
       When matching approximately, the shell keeps  a  count  of  the  errors
       found,  which  cannot exceed the number specified in the (#anum) flags.
       Four types of error are recognised:

       1.     Different characters, as in fooxbar and fooybar.

       2.     Transposition of characters, as in banana and abnana.

       3.     A character missing in the target string, as  with  the  pattern
              road and target string rod.

       4.     An extra character appearing in the target string, as with stove
              and strove.

       Thus, the pattern (#a3)abcd matches dcba, with the errors occurring  by
       using  the first rule twice and the second once, grouping the string as
       [d][cb][a] and [a][bc][d].

       Non-literal  parts  of  the  pattern  must  match  exactly,   including
       characters  in  character  ranges:  hence  (#a1)???  matches strings of
       length four, by applying rule 4 to an empty part of  the  pattern,  but
       not  strings  of  length  two,  since  all  the  ?  must  match.  Other
       characters which must match  exactly  are  initial  dots  in  filenames
       (unless  the GLOB_DOTS option is set), and all slashes in filenames, so
       that a/bc is two errors from ab/c (the slash cannot be transposed  with
       another  character).   Similarly,  errors  are  counted  separately for
       non-contiguous strings in the pattern, so that (ab|cd)ef is two  errors
       from aebf.

       When  using  exclusion  via  the  ~  operator,  approximate matching is
       treated entirely separately for the excluded part and must be activated
       separately.  Thus, (#a1)README~READ_ME matches READ.ME but not READ_ME,
       as the trailing READ_ME is  matched  without  approximation.   However,
       (#a1)README~(#a1)READ_ME does not match any pattern of the form READ?ME
       as all such forms are now excluded.

       Apart from exclusions, there is only one overall error count;  however,
       the  maximum  errors  allowed  may  be altered locally, and this can be
       delimited by grouping.  For example, (#a1)cat((#a0)dog)fox  allows  one
       error in total, which may not occur in the dog section, and the pattern
       (#a1)cat(#a0)dog(#a1)fox is equivalent.  Note that the point  at  which
       an  error is first found is the crucial one for establishing whether to
       use  approximation;  for  example,  (#a1)abc(#a0)xyz  will  not   match
       abcdxyz,  because  the  error occurs at the `x', where approximation is
       turned off.

       Entire  path  segments  may   be   matched   approximately,   so   that
       `(#a1)/foo/d/is/available/at/the/bar'  allows  one  error  in  any path
       segment.  This is much less efficient than without the (#a1),  however,
       since  every  directory  in  the  path  must  be scanned for a possible
       approximate match.  It is best  to  place  the  (#a1)  after  any  path
       segments which are known to be correct.

   Recursive Globbing
       A pathname component of the form `(foo/)#' matches a path consisting of
       zero or more directories matching the pattern foo.

       As a  shorthand,  `**/'  is  equivalent  to  `(*/)#';  note  that  this
       therefore   matches   files   in  the  current  directory  as  well  as
       subdirectories.  Thus:

              ls (*/)#bar

       or

              ls **/bar

       does a recursive directory search for files  named  `bar'  (potentially
       including the file `bar' in the current directory).  This form does not
       follow symbolic  links;  the  alternative  form  `***/'  does,  but  is
       otherwise identical.  Neither of these can be combined with other forms
       of globbing within the  same  path  segment;  in  that  case,  the  `*'
       operators revert to their usual effect.

   Glob Qualifiers
       Patterns  used  for filename generation may end in a list of qualifiers
       enclosed in parentheses.  The qualifiers specify which  filenames  that
       otherwise  match  the  given  pattern  will be inserted in the argument
       list.

       If the option BARE_GLOB_QUAL is set, then a trailing set of parentheses
       containing  no `|' or `(' characters (or `~' if it is special) is taken
       as a set of glob qualifiers.  A glob subexpression that would  normally
       be  taken  as  glob qualifiers, for example `(^x)', can be forced to be
       treated as part of the glob pattern by  doubling  the  parentheses,  in
       this case producing `((^x))'.

       If  the  option  EXTENDED_GLOB  is  set,  a  different  syntax for glob
       qualifiers is available, namely `(#qx)' where x is any of the same glob
       qualifiers  used in the other format.  The qualifiers must still appear
       at the end of the pattern.  However, with  this  syntax  multiple  glob
       qualifiers  may be chained together.  They are treated as a logical AND
       of the individual sets of flags.  Also, as the syntax  is  unambiguous,
       the  expression  will  be  treated  as glob qualifiers just as long any
       parentheses contained within it are balanced; appearance of `|', `(' or
       `~'  does  not  negate  the  effect.   Note  that  qualifiers  will  be
       recognised in this form even if a bare glob qualifier exists at the end
       of  the  pattern,  for  example  `*(#q*)(.)'  will recognise executable
       regular files if both options are set;  however,  mixed  syntax  should
       probably be avoided for the sake of clarity.

       A qualifier may be any one of the following:

       /      directories

       F      `full'  (i.e.  non-empty)  directories.   Note that the opposite
              sense (^F) expands to empty directories and all non-directories.
              Use (/^F) for empty directories.

       .      plain files

       @      symbolic links

       =      sockets

       p      named pipes (FIFOs)

       *      executable plain files (0100)

       %      device files (character or block special)

       %b     block special files

       %c     character special files

       r      owner-readable files (0400)

       w      owner-writable files (0200)

       x      owner-executable files (0100)

       A      group-readable files (0040)

       I      group-writable files (0020)

       E      group-executable files (0010)

       R      world-readable files (0004)

       W      world-writable files (0002)

       X      world-executable files (0001)

       s      setuid files (04000)

       S      setgid files (02000)

       t      files with the sticky bit (01000)

       fspec  files with access rights matching spec. This spec may be a octal
              number optionally preceded by a `=', a `+', or a `-'. If none of
              these  characters is given, the behavior is the same as for `='.
              The octal number describes the mode  bits  to  be  expected,  if
              combined  with  a `=', the value given must match the file-modes
              exactly, with a `+', at least the bits in the given number  must
              be set in the file-modes, and with a `-', the bits in the number
              must not be set. Giving a `?' instead of a octal digit  anywhere
              in  the  number  ensures  that  the  corresponding  bits  in the
              file-modes are not checked, this is only useful  in  combination
              with `='.

              If the qualifier `f' is followed by any other character anything
              up to the next matching character (`[', `{', and `<' match  `]',
              `}',  and  `>' respectively, any other character matches itself)
              is taken as a list of comma-separated sub-specs.  Each  sub-spec
              may  be  either  an octal number as described above or a list of
              any of the characters `u', `g', `o', and `a', followed by a `=',
              a  `+',  or  a  `-', followed by a list of any of the characters
              `r', `w', `x', `s', and `t', or an octal digit. The  first  list
              of  characters specify which access rights are to be checked. If
              a `u' is given, those for the owner of the file are used,  if  a
              `g'  is  given,  those  of the group are checked, a `o' means to
              test those of other users, and the `a' says to  test  all  three
              groups. The `=', `+', and `-' again says how the modes are to be
              checked and have the same meaning as  described  for  the  first
              form  above.  The  second  list of characters finally says which
              access rights are to be expected: `r' for read access,  `w'  for
              write  access,  `x'  for  the  right  to execute the file (or to
              search a directory), `s' for the setuid and setgid bits, and `t'
              for the sticky bit.

              Thus,  `*(f70?)'  gives  the files for which the owner has read,
              write, and execute permission, and for which other group members
              have  no rights, independent of the permissions for other users.
              The pattern `*(f-100)' gives all files for which the owner  does
              not  have  execute  permission,  and `*(f:gu+w,o-rx:)' gives the
              files for which the owner and the other  members  of  the  group
              have  at least write permission, and for which other users don't
              have read or execute permission.

       estring
       +cmd   The string will be executed as shell code.  The filename will be
              included  in  the  list  if  and only if the code returns a zero
              status (usually the status of the last command).

              In the first form, the first character after  the  `e'  will  be
              used  as  a  separator  and  anything  up  to  the next matching
              separator will be taken  as the string; `[', `{', and `<'  match
              `]',  `}',  and  `>',  respectively,  while  any other character
              matches itself. Note that  expansions  must  be  quoted  in  the
              string  to  prevent  them from being expanded before globbing is
              done.  string is  then  executed  as  shell  code.   The  string
              globqual  is appended to the array zsh_eval_context the duration
              of execution.

              During the execution of  string  the  filename  currently  being
              tested is available in the parameter REPLY; the parameter may be
              altered to a string to be inserted into the list instead of  the
              original  filename.  In addition, the parameter reply may be set
              to an array or a string, which overrides the value of REPLY.  If
              set  to  an  array, the latter is inserted into the command line
              word by word.

              For  example,  suppose  a  directory  contains  a  single   file
              `lonely'.   Then  the expression `*(e:'reply=(${REPLY}{1,2})':)'
              will cause the words `lonely1 lonely2' to be inserted  into  the
              command line.  Note the quotation marks.

              The  form  +cmd  has  the  same effect, but no delimiters appear
              around cmd.  Instead, cmd is taken as the  longest  sequence  of
              characters  following the + that are alphanumeric or underscore.
              Typically cmd will be the name of a shell function that contains
              the appropriate test.  For example,

                     nt() { [[ $REPLY -nt $NTREF ]] }
                     NTREF=reffile
                     ls -l *(+nt)

              lists  all  files  in the directory that have been modified more
              recently than reffile.

       ddev   files on the device dev

       l[-|+]ct
              files having a link count less than ct (-), greater than ct (+),
              or equal to ct

       U      files owned by the effective user ID

       G      files owned by the effective group ID

       uid    files  owned  by  user ID id if that is a number.  Otherwise, id
              specifies a user name: the character after the `u' will be taken
              as  a  separator and the string between it and the next matching
              separator will be taken as a user name.  The starting separators
              `[',  `{', and `<' match the final separators `]', `}', and `>',
              respectively; any other character matches itself.  The  selected
              files  are  those  owned by this user.  For example, `u:foo:' or
              `u[foo]' selects files owned by user `foo'.

       gid    like uid but with group IDs or names

       a[Mwhms][-|+]n
              files accessed exactly n days ago.  Files  accessed  within  the
              last  n  days  are  selected  using a negative value for n (-n).
              Files accessed more than n days ago are selected by a positive n
              value  (+n).  Optional unit specifiers `M', `w', `h', `m' or `s'
              (e.g. `ah5') cause the check to be performed with months (of  30
              days),  weeks,  hours,  minutes  or  seconds  instead  of  days,
              respectively.

              Any fractional part of the difference between  the  access  time
              and  the current part in the appropriate units is ignored in the
              comparison.  For  instance,  `echo  *(ah-5)'  would  echo  files
              accessed  within the last five hours, while `echo *(ah+5)' would
              echo files accessed at least six hours ago,  as  times  strictly
              between five and six hours are treated as five hours.

       m[Mwhms][-|+]n
              like  the  file  access  qualifier, except that it uses the file
              modification time.

       c[Mwhms][-|+]n
              like the file access qualifier, except that  it  uses  the  file
              inode change time.

       L[+|-]n
              files less than n bytes (-), more than n bytes (+), or exactly n
              bytes in length.

              If this flag is directly followed by a `k' (`K'), `m' (`M'),  or
              `p'  (`P') (e.g. `Lk-50') the check is performed with kilobytes,
              megabytes, or blocks (of 512 bytes) instead.   In  this  case  a
              file  is regarded as "exactly" the size if the file size rounded
              up to the next unit is equal to the test size.   Hence  `*(Lm1)'
              matches files from 1 byte up to 1 Megabyte inclusive.  Note also
              that the set of files "less than" the test  size  only  includes
              files  that  would  not match the equality test; hence `*(Lm-1)'
              only matches files of zero size.

       ^      negates all qualifiers following it

       -      toggles between making the qualifiers  work  on  symbolic  links
              (the default) and the files they point to

       M      sets the MARK_DIRS option for the current pattern

       T      appends a trailing qualifier mark to the filenames, analogous to
              the LIST_TYPES option, for the current pattern (overrides M)

       N      sets the NULL_GLOB option for the current pattern

       D      sets the GLOB_DOTS option for the current pattern

       n      sets the NUMERIC_GLOB_SORT option for the current pattern

       oc     specifies how the names of the files should be sorted. If c is n
              they  are  sorted  by  name  (the  default); if it is L they are
              sorted depending on the size (length) of the files;  if  l  they
              are sorted by the number of links; if a, m, or c they are sorted
              by the time of the last access, modification,  or  inode  change
              respectively;  if d, files in subdirectories appear before those
              in the current directory at each level of the search -- this  is
              best combined with other criteria, for example `odon' to sort on
              names for files within the same directory; if N, no  sorting  is
              performed.   Note  that  a, m, and c compare the age against the
              current time, hence the first name in the list is  the  youngest
              file.  Also  note  that  the  modifiers  ^  and  -  are used, so
              `*(^-oL)' gives a list of all  files  sorted  by  file  size  in
              descending  order,  following  any symbolic links.  Unless oN is
              used, multiple order specifiers may occur to resolve ties.

              oe and o+ are special cases; they are  each  followed  by  shell
              code,  delimited  as  for  the  e  glob qualifier and the + glob
              qualifier respectively (see above).  The code  is  executed  for
              each  matched  file  with the parameter REPLY set to the name of
              the file on entry and  globsort  appended  to  zsh_eval_context.
              The  code should modify the parameter REPLY in some fashion.  On
              return, the value of the parameter is used instead of  the  file
              name  as  the  string  on  which  to  sort.   Unlike  other sort
              operators, oe and o+ may be repeated, but note that the  maximum
              number of sort operators of any kind that may appear in any glob
              expression is 12.

       Oc     like `o', but sorts in descending order; i.e.  `*(^oc)'  is  the
              same  as  `*(Oc)' and `*(^Oc)' is the same as `*(oc)'; `Od' puts
              files in the current directory before those in subdirectories at
              each level of the search.

       [beg[,end]]
              specifies  which  of the matched filenames should be included in
              the  returned  list.  The  syntax  is  the  same  as  for  array
              subscripts.  beg  and  the  optional  end  may  be  mathematical
              expressions. As in parameter subscripting they may  be  negative
              to   make  them  count  from  the  last  match  backward.  E.g.:
              `*(-OL[1,3])' gives a list of the names  of  the  three  largest
              files.

       Pstring
              The  string  will  be prepended to each glob match as a separate
              word.  string is delimited in the same way as arguments to the e
              glob  qualifier described above.  The qualifier can be repeated;
              the words are prepended separately so that the resulting command
              line contains the words in the same order they were given in the
              list of glob qualifiers.

              A typical use for this  is  to  prepend  an  option  before  all
              occurrences  of a file name; for example, the pattern `*(P:-f:)'
              produces the command line arguments `-f file1 -f file2 ...'

       More than one of these lists can be combined, separated by commas.  The
       whole  list  matches  if at least one of the sublists matches (they are
       `or'ed, the qualifiers in the sublists are `and'ed).  Some  qualifiers,
       however,  affect  all  matches generated, independent of the sublist in
       which they are given.  These are the qualifiers  `M',  `T',  `N',  `D',
       `n', `o', `O' and the subscripts given in brackets (`[...]').

       If  a  `:' appears in a qualifier list, the remainder of the expression
       in  parenthesis  is  interpreted  as  a  modifier  (see   the   section
       `Modifiers' in the section `History Expansion').  Each modifier must be
       introduced by  a  separate  `:'.   Note  also  that  the  result  after
       modification  does  not  have  to be an existing file.  The name of any
       existing file can be followed by a modifier of the form `(:..)' even if
       no  actual  filename  generation  is  performed, although note that the
       presence  of  the  parentheses  causes  the  entire  expression  to  be
       subjected  to  any  global  pattern matching options such as NULL_GLOB.
       Thus:

              ls *(-/)

       lists all directories and symbolic links that point to directories, and

              ls *(%W)

       lists all world-writable device files in the current directory, and

              ls *(W,X)

       lists all files in the current directory  that  are  world-writable  or
       world-executable, and

              echo /tmp/foo*(u0^@:t)

       outputs  the basename of all root-owned files beginning with the string
       `foo' in /tmp, ignoring symlinks, and

              ls *.*~(lex|parse).[ch](^D^l1)

       lists all files having a link count of one whose names  contain  a  dot
       (but  not  those  starting  with  a  dot, since GLOB_DOTS is explicitly
       switched off) except for lex.c, lex.h, parse.c and parse.h.

              print b*.pro(#q:s/pro/shmo/)(#q.:s/builtin/shmiltin/)

       demonstrates how colon modifiers and other qualifiers  may  be  chained
       together.   The ordinary qualifier `.' is applied first, then the colon
       modifiers in order from left to right.  So if EXTENDED_GLOB is set  and
       the  base  pattern matches the regular file builtin.pro, the shell will
       print `shmiltin.shmo'.