Provided by: zsh_4.3.4-24ubuntu1_i386 bug


       zshexpn - zsh expansion and substitution


       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 β€˜\’, β€˜β€β€™β€™ and β€˜"’ 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

       The following sections explain the types of expansion in detail.


       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  Prompt  Expansion  in
       zshmisc(1)) is the number that is to be assigned to the next command.

       A  history  expansion  begins with the first character of the histchars
       parameter, which is β€˜!’ by default,  and  may  occur  anywhere  on  the
       command  line;  history expansions do not nest.  The β€˜!’ can be escaped
       with β€˜\’ or can be enclosed between a pair of  single  quotes  (β€β€™β€β€™)  to
       suppress  its  special  meaning.  Double quotes will not work for this.
       Following this history character is an optional event  designator  (see
       the  section  β€˜Event Designators’) and then an optional word designator
       (the section β€˜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,  β€˜!’ is the event designator for the previous command, so
       β€˜!!:1’ always refers to the first word of  the  previous  command,  and
       β€˜!!$’  always  refers  to  the last word of the previous command.  With
       CSH_JUNKIE_HISTORY set, then β€˜!:1’ and β€˜!$’ function in the same manner
       as  β€˜!!:1’  and β€˜!!$’, respectively.  Conversely, if CSH_JUNKIE_HISTORY
       is unset, then β€˜!:1’ and β€˜!$’  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  β€˜^foo^bar’  (where β€˜^’ is actually the second
       character  of  the  histchars  parameter)  repeats  the  last  command,
       replacing  the  string  foo  with  bar.   More  precisely, the sequence
       β€˜^foo^bar^’ is synonymous with β€˜!!:s^foo^bar^’, hence  other  modifiers
       (see the section β€˜Modifiers’) may follow the final β€˜^’.  In particular,
       β€˜^foo^bar:G’ performs a global substitution.

       If the shell encounters the character sequence β€˜!"’ in the  input,  the
       history  mechanism  is temporarily disabled until the current list (see
       zshmisc(1)) is fully parsed.  The β€˜!"’ is removed from the  input,  and
       any subsequent β€˜!’ 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 β€β€˜!β€β€™ in each
       item may be changed to  another  character  by  setting  the  histchars

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

       !!     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.

              Refer to the most recent command containing str.   The  trailing
              β€˜?’  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 β€˜!#’ reference.

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

   Word Designators
       A word designator indicates which word or words of a given command line
       are to be included in a history reference.  A β€˜:’ usually separates the
       event specification from the word designator.  It may be  omitted  only
       if  the  word designator begins with a β€˜^’, β€˜$’, β€˜*’, β€˜-’ or β€˜%’.  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 β€˜x-$’.
       x-     Like β€˜x*’ but omitting word $.

       Note that a β€˜%’ word designator works only when used in  one  of  β€˜!%’,
       β€˜!:%’  or β€˜!?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.

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

       h      Remove a trailing pathname component, leaving  the  head.   This
              works like β€˜dirname’.

       r      Remove a filename extension of the form β€˜.xxx’, leaving the root

       e      Remove all but the extension.

       t      Remove all leading pathname components, leaving the tail.   This
              works like β€˜basename’.

       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.

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

       l      Convert the words to all lowercase.

       u      Convert the words to all uppercase.

              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  β€˜gs/l/r’ and β€˜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.

       &      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.

       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  β€˜/’.   A  backslash
       quotes   the   delimiter   character.    The   character  β€˜&’,  in  the
       right-hand-side r, is replaced by the text from the  left-hand-side  l.
       The  β€˜&’  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  β€˜!?s’.   You  can  omit  the  rightmost  delimiter  if  a newline
       immediately follows  r;  the  rightmost  β€˜?’  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.

       If the option HIST_SUBST_PATTERN is set, l is treated as a  pattern  of
       the usual form desribed 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 qualifer.  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/β€β€™S${match[1]}.Cβ€β€™/)

       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

       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.

              Like f,  but  repeats  only  n  times  if  the  expression  expr
              evaluates  to  n.  Any character can be used instead of the β€˜:’;
              if β€˜(’, β€˜[’, or β€˜{’  is  used  as  the  opening  delimiter,  the
              closing delimiter should be ’)’, β€˜]’, or β€˜}’, 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 β€˜:’; opening parentheses are handled specially, see above.


       Each command argument of the form β€˜<(list)’, β€˜>(list)’ or β€˜=(list)’  is
       subject  to process substitution.  In the case of the < or > forms, the
       shell runs process list asynchronously.  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

       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

       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.  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.


       The  character  β€˜$’  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

       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  β€˜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  β€˜Modifiers’ in the section β€˜History Expansion’ can be
       applied:  for example, ${i:s/foo/bar/} performs string substitution  on
       the expansion of parameter $i.

              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 β€˜^’, β€˜=’, β€˜~’,  β€˜#’  or
              β€˜+’ appearing before the name, all of which work with or without

              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

              If name is the name of  a  set  parameter  β€˜1’  is  substituted,
              otherwise β€˜0’ is substituted.

              If  name  is  set  and  is  non-null  then substitute its value;
              otherwise substitute word. If name is missing, substitute  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 the s:string: flag.

              In  the  first  form, if name is unset or is null then set it to
              word; in the second form, unconditionally set name to word.   In
              both forms, the value of the parameter is then substituted.

              If  name  is  set  and  is  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.

              If name is set and is non-null then substitute  word;  otherwise
              substitute  nothing.   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 the
              s:string: flag.

       If the colon is omitted from one of the above expressions containing  a
       colon,  then the shell only checks whether name is set, not whether its
       value is null.

       In  the  following  expressions,  when  name  is  an  array   and   the
       substitution  is not quoted, or if the β€˜(@)’ flag or the name[@] syntax
       is used, matching and replacement is performed on  each  array  element

              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.

              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.

              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 β€˜(M)’ flag to remove the non-matched elements).

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

              The first β€˜/’ may be preceded by a β€˜:’, 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  β€˜~’  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 β€˜spy
              star’, while in the second case, the shortest matches are  taken
              and the result is β€˜spy spy lispy star’.

              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 β€˜^’, β€˜=’, and β€˜~’, below, must  appear
              to the left of β€˜#’ when these forms are combined.

              Turn  on  the RC_EXPAND_PARAM option for the evaluation of spec;
              if the β€˜^’ 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  β€˜fooabar  foobbar
              foocbar’ instead of the default β€˜fooa b cbar’.

              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 β€˜Brace Expansion’ below.  If word splitting is  also  in
              effect  the  $var[N] may themselves be split into different list

              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 β€˜=’ 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.

              Turn on the GLOB_SUBST option for the evaluation of spec; if the
              β€˜~’ 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 β€˜=’ and β€˜!=’ 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

       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 β€˜head’ and β€˜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 $(foo), but the flag β€˜(f)’ (see
       below) is applied  using  the  rules  for  unquoted  expansions.   Note
       further that quotes are themselves nested in this context; for example,
       in "${(@f)"$(foo)"}", there are two sets of quotes, one surrounding the
       whole  expression,  the  other  (redundant)  surrounding  the $(foo) as

   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, β€˜(q%q%q)’ means the
       same thing as the more readable β€˜(%%qqq)’.   The  following  flags  are

       #      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

              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

       %      Expand all % escapes in the resulting words in the same  way  as
              in prompts (see the section β€˜Prompt Expansion’). 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.,   β€˜"${(@)foo}"’   is   equivalent   to  β€˜"${foo[@]}"’  and
              β€˜"${(@)foo[1,2]}"’ is the same as β€˜"$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  β€˜${...=...}’,  β€˜${...:=...}’  or
              β€˜${...::=...}’.   If  this flag is repeated (as in β€˜AA’), create
              an associative  array  parameter.   Assignment  is  made  before
              sorting  or  padding.   The name part may be a subscripted range
              for ordinary arrays; the word  part  must  be  converted  to  an
              array, for example by using β€˜${(AA)=name=...}’ to activate field
              splitting, when creating an associative array.

       a      Sort in array index  order;  when  combined  with  β€˜O’  sort  in
              reverse   array   index  order.   Note  that  β€˜a’  is  therefore
              equivalent to the default but β€˜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.  β€˜Words’ in this case refers  to
              sequences    of    alphanumeric    characters    separated    by
              non-alphanumerics,  not  to  words  that   result   from   field

       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 to lines. This is a shorthand
              for β€˜ps:\n:’.

       F      Join the words of arrays together using newline as a  separator.
              This is a shorthand for β€˜pj:\n:’.

       i      Sort case-insensitively.  May be combined with β€˜n’ or β€˜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

       L      Convert all letters in the result to lower case.

       n      Sort  decimal  numbers  numerically;  if  the  first   differing
              characters  of  two  test  strings  are  not  digits, sorting is
              lexical.   Numbers with initial zeroes are sorted  before  those
              without.   Hence the array β€˜foo1 foo02 foo2 foo3 foo20 foo23’ is
              sorted into  the  order  shown.   Trailing  non-digits  are  not
              sorted;  the  order of β€˜2foo’ and β€˜2bar’ is not defined.  May be
              combined with β€˜i’ or β€˜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 β€˜a’, β€˜i’ or β€˜n’.

       O      Sort the resulting words in descending order; β€˜O’  without  β€˜a’,
              β€˜i’ or β€˜n’ sorts in reverse lexical order.  May be combined with
              β€˜a’, β€˜i’ or β€˜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.  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  β€˜foo=bar’  and
              β€˜bar=baz’,  the strings ${(P)foo}, ${(P)${foo}}, and ${(P)$(echo
              bar)} will be expanded to β€˜baz’.

       q      Quote the resulting words with  backslashes.  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.  If  it  is  given  four  times, the words are quoted in
              single quotes preceded by a $.

       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  (β€˜-’).  The  first
              keyword  in the string describes the main type, it can be one of
              β€˜scalar’, β€˜array’,  β€˜integer’,  β€˜float’  or  β€˜association’.  The
              other keywords describe the type in more detail:

              local  for local parameters

              left   for left justified parameters

                     for right justified parameters with leading blanks

                     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

                     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 β€˜hide’ flag

                     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  β€˜${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

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

       0      Split the result of the expansion on  null  bytes.   This  is  a
              shorthand for β€˜ps:\0:’.

       The following flags (except p) are followed by one or more arguments as
       shown.  Any character, or the matching pairs β€˜(...)’, β€˜{...}’, β€˜[...]’,
       or  β€˜<...>’,  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.

              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.

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

              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 l and r when the MULTIBYTE option is
              in effect.  Use the character width reported by  the  system  in
              calculating  the  how  much  of  the  string  it occupies.  Most
              printable characters have a width of one unit,  however  certain
              Asian  character  sets  and  certain  special  effects use wider

              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.

              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.

       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.

              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  β€˜which’, β€˜witch’, β€˜witch’ and
              β€˜wich’; the form using β€˜##’ will match and remove β€˜which  switch
              is the right switch for Ipswich’, β€˜witch is the right switch for
              Ipswich’, β€˜witch for Ipswich’ and β€˜wich’.  The  form  using  β€˜%’
              will  remove  the same matches as for β€˜#’, but in reverse order,
              and the form using β€˜%%’ will remove the same matches as for β€˜##’
              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).

       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
              β€˜(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

       2. 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.

       3. 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

       4. 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

       5. 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 2., 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).

       6. Modifiers
              Any  modifiers,  as  specified  by  a  trailing  β€˜#’,  β€˜%’,  β€˜/’
              (possibly doubled) or by a set of modifiers  of  the  form  :...
              (see   the   section   β€˜Modifiers’   in   the  section  β€˜History
              Expansion’), are applied to the  words  of  the  value  at  this

       7. Forced Joining
              If  the  β€˜(j)’  flag is present, or no β€˜(j)’ flag is present but
              the string is to be split as  given  by  rules  8.  or  9.,  and
              joining  did  not  take place at step 4., any words in the value
              are  joined  together  using  the  given  string  or  the  first
              character  of $IFS if none.  Note that the β€˜(F)’ flag implicitly
              supplies a string for joining in this manner.

       8. Forced Splitting
              If one of the β€˜(s)’, β€˜(f)’ or β€˜(z)’ flags are  present,  or  the
              β€˜=’  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.

       9. Shell Word Splitting
              If  no β€˜(s)’, β€˜(f)’ or β€˜=’ 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.

       10. Uniqueness
              If the result is an  array  and  the  β€˜(u)’  flag  was  present,
              duplicate elements are removed from the array.

       11. Ordering
              If  the  result  is still an array and one of the β€˜(o)’ or β€˜(O)’
              flags was present, the array is reordered.

       12. Re-Evaluation
              Any β€˜(e)’ flag is  applied  to  the  value,  forcing  it  to  be
              re-examined  for  new  parameter  substitutions,  but  also  for
              command and arithmetic substitutions.

       13. Padding
              Any padding of the value by the β€˜(l.fill.)’ or β€˜(r.fill.)’ flags
              is applied.

       14. 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  β€˜${(P)${(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.

       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):

              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  β€˜(@)’  flag)  the
              subscript picks the first character.

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

       As an example of the rules for word splitting and joining, suppose $foo
       contains the array β€˜(ax1 bx1)’.  Then

              produces the words β€˜a’, β€˜1 b’ and β€˜1’.

              produces β€˜a’, β€˜1’, β€˜b’ and β€˜1’.

              produces β€˜a’ and β€˜ 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 β€˜a’, β€˜ b’ and β€˜β€™.  The final
              empty string will then be elided, as it is not in double quotes.


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


       A string of the form β€˜$[exp]’ or β€˜$((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 β€˜Arithmetic Evaluation’.


       A  string  of the form β€˜foo{xx,yy,zz}bar’ is expanded to the individual
       words β€˜fooxxbar’, β€˜fooyybar’ and β€˜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 β€˜{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.  If the numbers are in decreasing
       order the resulting sequence will also be in decreasing order.

       If a brace expression matches none of  the  above  forms,  it  is  left
       unchanged,  unless  the  BRACE_CCL  option is set.  In that case, it is
       expanded to a sorted list of  the  individual  characters  between  the
       braces,  in the manner of a search set.  β€˜-’ is treated specially as in
       a search set, but  β€˜^’  or  β€˜!’  as  the  first  character  is  treated

       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 β€˜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.


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

       A β€˜~’ by itself is replaced by the value of $HOME.  A β€˜~’ followed by a
       β€˜+’ or a β€˜-’ is replaced by the value of $PWD or $OLDPWD, respectively.

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

       A β€˜~’ followed by anything not already covered 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 β€˜~’ is the name
       of a string shell parameter whose value begins with a β€˜/’.   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 β€˜~’
       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.

       If a word begins with an unquoted β€˜=’ 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

       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 β€˜~’
       or an β€˜=’  following  a  β€˜:’  is  eligible  for  expansion.   All  such
       behaviour  can  be  disabled  by quoting the β€˜~’, the β€˜=’, or the whole
       expression (but not simply  the  colon);  the  EQUALS  option  is  also

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


       If a word contains an unquoted instance of one of the  characters  β€˜*’,
       β€˜(’,  β€˜|’,  β€˜<’,  β€˜[’, or β€˜?’, it is regarded as a pattern for filename
       generation, unless the GLOB option  is  unset.   If  the  EXTENDED_GLOB
       option  is  set,  the  β€˜^’  and  β€˜#’  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 β€˜/’ must be  matched  explicitly;
       also, a β€˜.’ must be matched explicitly at the beginning of a pattern or
       after  a  β€˜/’,  unless  the  GLOB_DOTS  option  is  set.   No  filename
       generation  pattern  matches the files β€˜.’ or β€˜..’.  In other instances
       of pattern matching, the β€˜/’ and β€˜.’ 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 β€˜-’.  A β€˜-’
              or β€˜]’ may be matched by including it as the first character  in
              the  list.   There are also several named classes of characters,
              in the form β€˜[: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):

                     The character is alphanumeric

                     The character is alphabetic

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

                     The character is either space or tab

                     The character is a control character

                     The character is a decimal digit

                     The  character  is  a  printable  character  other   than

                     The character is a lowercase letter

                     The character is printable

                     The  character  is printable but neither alphanumeric nor

                     The character is whitespace

                     The character is an uppercase letter

                     The character is a hexadecimal digit

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

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

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

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

                     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 β€˜[[:alnum:]]’.  Named character
              sets can be used alongside other types, e.g. β€˜[[:alpha:]0-9]’.

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

              Matches  any  number  in the range x to y, inclusive.  Either of
              the numbers may be omitted to make the range  open-ended;  hence
              β€˜<->’ 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  β€˜<0-9>’  will
              match  the first digit, and the β€˜*’ 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 β€˜<0-9>[^[:digit:]]*’ can be  used

       (...)  Matches  the  enclosed  pattern.  This is used for grouping.  If
              the KSH_GLOB option is set, then a β€˜@’, β€˜*’,  β€˜+’,  β€˜?’  or  β€˜!’
              immediately  preceding the β€˜(’ 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 β€˜/’ 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 β€˜|’ 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 β€˜/’, so β€˜^foo/bar’
              will  search  directories in β€˜.’ except β€˜./foo’ for a file named

       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 β€˜|’, so β€˜*/*~foo/bar’ will  search  for
              all  files in all directories in β€˜.’  and then exclude β€˜foo/bar’
              if there was such a match.  Multiple patterns can be excluded by
              β€˜foo~bar~baz’.   In  the  exclusion pattern (y), β€˜/’ and β€˜.’ 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; β€˜12#’ is equivalent to β€˜1(2#)’, rather than β€˜(12)#’.
              It  is  an  error  for an unquoted β€˜#’ to follow something which
              cannot be repeated; this includes an  empty  string,  a  pattern
              already followed by β€˜##’, or parentheses when part of a KSH_GLOB
              pattern (for example, β€˜!(foo)#’ is invalid and must be  replaced
              by β€˜*(!(foo))’).

       x##    (Requires  EXTENDED_GLOB  to  be  set.)   Matches  one  or  more
              occurrences  of  the  pattern  x.   This   operator   has   high
              precedence;  β€˜12##’  is  equivalent  to  β€˜1(2##)’,  rather  than
              β€˜(12)##’.  No more than two active  β€˜#’  characters  may  appear
              together.  (Note the potential clash with glob qualifiers in the
              form β€˜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 β€˜@’, β€˜*’, β€˜+’, β€˜?’ or β€˜!’.  This character need
       not be unquoted to have special effects, but the β€˜(’ must be.

       @(...) Match the pattern in the parentheses.  (Like β€˜(...)’.)

       *(...) Match any number of occurrences.  (Like β€˜(...)#’.)

       +(...) Match at least one occurrence.  (Like β€˜(...)##’.)

       ?(...) Match zero or one occurrence.  (Like β€˜(|...)’.)

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

       The precedence of the operators given above is (highest) β€˜^’, β€˜/’, β€˜~’,
       β€˜|’ (lowest); the remaining operators are simply treated from  left  to
       right  as  part of a string, with β€˜#’ and β€˜##’ applying to the shortest
       possible preceding unit (i.e. a character, β€˜?’, β€˜[...]’, β€˜<...>’, or  a
       parenthesised  expression).   As  mentioned  above,  a  β€˜/’  used  as a
       directory separator may not appear inside parentheses, while a β€˜|’ must
       do so; in patterns used in other contexts than filename generation (for
       example, in case statements and tests within β€˜[[...]]’), a β€˜/’  is  not
       special;  and  β€˜/’  is  also  not special after a β€˜~’ 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)β€β€™ β€β€™(#b)(*)β€β€™ β€β€™* ]]; then
                       print ${foo[$mbegin[1],$mend[1]]}

              prints  β€˜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 β€˜#’ or β€˜##’.  Only the
              last match of the parenthesis is remembered: for example, in β€˜[[
              abab  =  (#b)([ab])#  ]]’,  only  the  final  β€˜b’  is  stored in
              match[1].  Thus extra parentheses may be necessary to match  the
              complete  segment:  for  example,  use β€˜X((ab|cd)#)Y’ to match a
              whole string of either β€˜ab’ or β€˜cd’ between β€˜X’ and  β€˜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

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

       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 β€˜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

       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:  β€˜(#s)’ and β€˜(#e)’ are the only valid
              forms.  The β€˜(#s)’ flag succeeds only at the start of  the  test
              string, and the β€˜(#e)’ flag succeeds only at the end of the test
              string; they correspond to  β€˜^’  and  β€˜$’  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,
              β€˜*((#s)|/)test((#e)|/)*’ matches a path segment β€˜test’ in any of
              the   following   strings:   test,  test/at/start,  at/end/test,

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

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

       q      A  β€˜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 β€˜(#b)(*).c(#q.)’ can be used both
              for  globbing  and for matching against a string.  In the former
              case, the β€˜(#q.)’ will be treated as a glob  qualifier  and  the
              β€˜(#b)’  will  not be useful, while in the latter case the β€˜(#b)’
              is useful for backreferences and the β€˜(#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 β€˜x’, where approximation is
       turned off.

       Entire  path  segments  may   be   matched   approximately,   so   that
       β€˜(#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 β€˜(foo/)#’ matches a path consisting of
       zero or more directories matching the pattern foo.

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

              ls (*/)#bar


              ls **/bar

       does a recursive directory search for files  named  β€˜bar’  (potentially
       including the file β€˜bar’ in the current directory).  This form does not
       follow symbolic  links;  the  alternative  form  β€˜***/’  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  β€˜*’
       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

       If the option BARE_GLOB_QUAL is set, then a trailing set of parentheses
       containing  no β€˜|’ or β€˜(’ characters (or β€˜~’ 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 β€˜(^x)’, can be forced to be
       treated as part of the glob pattern by  doubling  the  parentheses,  in
       this case producing β€˜((^x))’.

       If  the  option  EXTENDED_GLOB  is  set,  a  different  syntax for glob
       qualifiers is available, namely β€˜(#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 β€˜|’, β€˜(’ or
       β€˜~’  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  β€˜*(#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      β€˜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 β€˜=’, a β€˜+’, or a β€˜-’. If none of
              these  characters is given, the behavior is the same as for β€˜=’.
              The octal number describes the mode  bits  to  be  expected,  if
              combined  with  a β€˜=’, the value given must match the file-modes
              exactly, with a β€˜+’, at least the bits in the given number  must
              be set in the file-modes, and with a β€˜-’, the bits in the number
              must not be set. Giving a β€˜?’ 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 β€˜=’.

              If the qualifier β€˜f’ is followed by any other character anything
              up to the next matching character (β€˜[’, β€˜{’, and β€˜<’ match  β€˜]’,
              β€˜}’,  and  β€˜>’ 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 β€˜u’, β€˜g’, β€˜o’, and β€˜a’, followed by a β€˜=’,
              a  β€˜+’,  or  a  β€˜-’, followed by a list of any of the characters
              β€˜r’, β€˜w’, β€˜x’, β€˜s’, and β€˜t’, or an octal digit. The  first  list
              of  characters specify which access rights are to be checked. If
              a β€˜u’ is given, those for the owner of the file are used,  if  a
              β€˜g’  is  given,  those  of the group are checked, a β€˜o’ means to
              test those of other users, and the β€˜a’ says to  test  all  three
              groups. The β€˜=’, β€˜+’, and β€˜-’ 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: β€˜r’ for read access,  β€˜w’  for
              write  access,  β€˜x’  for  the  right  to execute the file (or to
              search a directory), β€˜s’ for the setuid and setgid bits, and β€˜t’
              for the sticky bit.

              Thus,  β€˜*(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 β€˜*(f-100)’ gives all files for which the owner  does
              not  have  execute  permission,  and β€˜*(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.

       +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).   The  first
              character after the β€˜e’ will be used as a separator and anything
              up to the next matching separator will be taken  as the  string;
              β€˜[’,  β€˜{’,  and β€˜<’ match β€˜]’, β€˜}’, and β€˜>’, 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.

              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
              β€˜lonely’.   Then  the expression β€˜*(e:β€β€™reply=(${REPLY}{1,2})β€β€™:)’
              will cause the words β€˜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 ]] }
                     ls -l *(+nt)

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

       ddev   files on the device dev

              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 β€˜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
              β€˜[’,  β€˜{’, and β€˜<’ match the final separators β€˜]’, β€˜}’, and β€˜>’,
              respectively; any other character matches itself.  The  selected
              files  are  those  owned by this user.  For example, β€˜u:foo:’ or
              β€˜u[foo]’ selects files owned by user β€˜foo’.

       gid    like uid but with group IDs or names

              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 β€˜M’, β€˜w’, β€˜h’, β€˜m’ or β€˜s’
              (e.g. β€˜ah5’) cause the check to be performed with months (of  30
              days),  weeks,  hours,  minutes  or  seconds  instead  of  days,
              respectively.  For instance, β€˜echo  *(ah-5)’  would  echo  files
              accessed within the last five hours.

              like  the  file  access  qualifier, except that it uses the file
              modification time.

              like the file access qualifier, except that  it  uses  the  file
              inode change time.

              files less than n bytes (-), more than n bytes (+), or exactly n
              bytes in length. If this flag is  directly  followed  by  a  β€˜k’
              (β€˜K’),  β€˜m’  (β€˜M’),  or  β€˜p’  (β€˜P’)  (e.g. β€˜Lk-50’) the check is
              performed with kilobytes, megabytes, or blocks  (of  512  bytes)

       ^      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 β€˜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
              β€˜*(^-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.

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

              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.:
              β€˜*(-OL[1,3])’  gives  a  list  of the names of the three largest

       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
       β€˜or’ed, the qualifiers in the sublists are β€˜and’ed).  Some  qualifiers,
       however,  affect  all  matches generated, independent of the sublist in
       which they are given.  These are the qualifiers  β€˜M’,  β€˜T’,  β€˜N’,  β€˜D’,
       β€˜n’, β€˜o’, β€˜O’ and the subscripts given in brackets (β€˜[...]’).

       If  a  β€˜:’ appears in a qualifier list, the remainder of the expression
       in  parenthesis  is  interpreted  as  a  modifier  (see   the   section
       β€˜Modifiers’  in  the  section  β€˜History  Expansion’).   Note  that each
       modifier must be introduced by a separate  β€˜:’.   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
       β€˜(:..)’ even if no actual filename generation is performed.  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
       β€˜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 β€˜.’ 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, the shell will
       print β€˜shmiltin.shmo’.