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ZSHEXPN(1)							    ZSHEXPN(1)

       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  charac-
	      ters `\',	`'' and	`"' are	removed.

       Filename	Expansion
	      If  the  SH_FILE_EXPANSION option	is set,	the order of expansion
	      is modified for compatibility with sh and	 ksh.	In  that  case
	      filename	expansion  is performed	immediately after alias	expan-
	      sion, 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  correc-
       tions and the repetition	of complicated commands	or arguments.

       Immediately  before  execution,	each  command  is saved	in the history
       list, the size of which is controlled by	the HISTSIZE  parameter.   The
       one  most  recent  command  is always retained in any case.  Each saved
       command in the history list is called a history event and is assigned a
       number,	beginning  with	1 (one)	when the shell starts up.  The history
       number that you may  see	 in  your  prompt  (see	 EXPANSION  OF	PROMPT
       SEQUENCES  in  zshmisc(1))  is the number that is to be assigned	to the
       next command.

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

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

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

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

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

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

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

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

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

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

       !n     Refer to command-line n.

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

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

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

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

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

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

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

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

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

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

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

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

       e      Remove all but the part of the filename extension	following  the
	      `.';  see	 the  definition  of  the  filename  extension	in the
	      description of the r modifier below.   Note  that	 according  to
	      that definition the result will be empty if the string ends with
	      a	`.'.

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

       l      Convert the words	to all lowercase.

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

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

       Q      Remove one level of quotes from the substituted words.

       r      Remove a filename	extension leaving the root name.  Strings with
	      no filename extension are	not altered.  A	filename extension  is
	      a	`.' followed by	any number of characters (including zero) that
	      are neither `.' nor `/' and that continue	 to  the  end  of  the
	      string.  For example, the	extension of `foo.orig.c' is `.c', and
	      `dir.c/foo' has no extension.

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

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

	      See further notes	on this	form of	substitution below.

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

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

       u      Convert the words	to all uppercase.

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

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

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

       Also  note that the order of expansions affects the interpretation of l
       and r.  When used in a history expansion, which occurs before any other
       expansions, l and r are treated as literal strings (except as explained
       for HIST_SUBST_PATTERN below).  When used in parameter  expansion,  the
       replacement of r	into the parameter's value is done first, and then any
       additional process, parameter, command, arithmetic, or brace references
       are applied, which may evaluate those substitutions and expansions more
       than once if l appears more than	once in	the starting value.  When used
       in a glob qualifier, any	substitutions or expansions are	performed once
       at the time the qualifier is parsed, even before	 the  `:s'  expression
       itself is divided into l	and r sides.

       If  the	option HIST_SUBST_PATTERN is set, l is treated as a pattern of
       the usual form described	in  the	 section  FILENAME  GENERATION	below.
       This can	be used	in all the places where	modifiers are available; note,
       however,	that in	globbing qualifiers parameter substitution has already
       taken  place,  so parameters in the replacement string should be	quoted
       to ensure they are replaced at the correct time.	 Note also  that  com-
       plicated	 patterns  used	 in  globbing qualifiers may need the extended
       glob qualifier notation (#q:s/.../.../) in order	for the	shell to  rec-
       ognize the expression as	a glob qualifier.  Further, note that bad pat-
       terns 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 pat-
       tern must match at the end of the string	to be substituted.  The	% or #
       may be quoted with two backslashes.

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

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

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

       The following f,	F, w and W modifiers work only with  parameter	expan-
       sion 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	evalu-
	      ates to n.  Any character	can be used instead  of	 the  `:';  if
	      `(',  `[',  or `{' is used as the	opening	delimiter, the closing
	      delimiter	should be ')', `]', or `}', respectively.

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

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

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

       Note that `<<(list)' is not a special syntax; it	is  equivalent	to  `<
       <(list)', redirecting standard input from the result of process substi-
       tution.	Hence all the following	 documentation	applies.   The	second
       form (with the space) is	recommended for	clarity.

       In the case of the < or > forms,	the shell runs the commands in list as
       a subprocess of the job executing the shell command line.  If the  sys-
       tem 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  spe-
       cial  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 argu-
       ment 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 substi-
       tutions	have been performed.  This is handled entirely within the cur-
       rent 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 implementa-
       tion 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 sub-
       shell attempting	to read	from or	write to the pipe will (in  a  typical
       implementation,	different  operating systems may have different	behav-
       iour) block for ever and	have to	be killed explicitly.  In both	cases,
       the  shell actually supplies the	information using a pipe, so that pro-
       grammes that expect to lseek (see lseek(2)) on the file will not	 work.

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

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

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

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

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

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

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

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

       Another problem arises any time a job with a substitution that requires
       a  temporary  file  is  disowned	by the shell, including	the case where
       `&!' or `&|' appears at the end of a command containing a substitution.
       In  that	case the temporary file	will not be cleaned up as the shell no
       longer has any memory of	the job.  A workaround is to use  a  subshell,
       for example,

	      (mycmd =(myoutput)) &!

       as  the forked subshell will wait for the command to finish then	remove
       the temporary file.

       A general workaround to ensure a	process	substitution  endures  for  an
       appropriate length of time is to	pass it	as a parameter to an anonymous
       shell function (a piece of shell	code  that  is	run  immediately  with
       function	scope).	 For example, this code:

	      () {
		 print File $1:
		 cat $1
	      }	=(print	This be	the verse)

       outputs something resembling the	following

	      File /tmp/zsh6nU0kS:
	      This be the verse

       The  temporary file created by the process substitution will be deleted
       when the	function exits.

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

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

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

	      The  value,  if  any, of the parameter name is substituted.  The
	      braces are required if the expansion is to be followed by	a let-
	      ter,  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  sub-
	      script  or  any colon modifiers appearing	after the name,	or any
	      of the characters	`^', `=', `~', `#' or `+' appearing before the
	      name, all	of which work with or without braces.

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

	      If  name is the name of a	set parameter `1' is substituted, oth-
	      erwise `0' is substituted.

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

	      If name is set, or in the	second form is non-null, then  substi-
	      tute word; otherwise substitute nothing.

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

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

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

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

	      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 sub-
	      stitute the value	of name	with the matched portion deleted; oth-
	      erwise,  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 `(M)'	flag to	remove the non-matched elements).

	      If arrayname is the name (N.B., not contents) of an array	 vari-
	      able,  then any elements contained in arrayname are removed from
	      the substitution of name.	 If the	substitution is	scalar,	either
	      because  name  is	a scalar variable or the expression is quoted,
	      the elements of arrayname	are instead tested against the	entire

	      Similar  to  the	preceding  substitution,  but  in the opposite
	      sense, so	that entries present in	both the original substitution
	      and as elements of arrayname are retained	and others removed.

	      Zips  two	arrays,	such that the output array is twice as long as
	      the shortest (longest for	`:^^') of name and arrayname, with the
	      elements	alternatingly being picked from	them. For `:^',	if one
	      of the input arrays is longer, the output	will stop when the end
	      of the shorter array is reached.	Thus,

		     a=(1 2 3 4); b=(a b); print ${a:^b}

	      will  output  `1	a 2 b'.	 For `:^^', then the input is repeated
	      until all	of the longer array has	been used  up  and  the	 above
	      will output `1 a 2 b 3 a 4 b'.

	      Either  or  both inputs may be a scalar, they will be treated as
	      an array of length 1 with	the scalar as  the  only  element.  If
	      either  array  is	empty, the other array is output with no extra
	      elements inserted.

	      Currently	the following code will	output `a b' and  `1'  as  two
	      separate	elements,  which  can  be unexpected. The second print
	      provides a workaround which should continue to work if  this  is

		     a=(a b); b=(1 2); print -l	"${a:^b}"; print -l "${${a:^b}}"

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

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

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

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

	      When positive, length counts from	the offset position toward the
	      end of the scalar	or array.  When	negative, length  counts  back
	      from  the	 end.  If this results in a position smaller than off-
	      set, a diagnostic	is printed and nothing is substituted.

	      The option MULTIBYTE is obeyed, i.e. the offset and length count
	      multibyte	characters where appropriate.

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

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

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

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

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

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

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

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

	      For example,

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

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

	      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.  This has the side-effect that joining is skipped
	      even in quoted forms, which may affect other sub-expressions  in
	      spec.   Note  that  `^', `=', and	`~', below, must appear	to the
	      left of `#' when these forms are combined.

	      If the option POSIX_IDENTIFIERS is not set, and spec is a	simple
	      name,  then  the braces are optional; this is true even for spe-
	      cial parameters so e.g. $#- and  $#*  take  the  length  of  the
	      string  $-  and the array	$* respectively.  If POSIX_IDENTIFIERS
	      is set, then braces are required for the # to be treated in this

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

	      Internally, each such expansion is converted into	the equivalent
	      list    for    brace    expansion.     E.g.,   ${^var}   becomes
	      {$var[1],$var[2],...}, and is processed as described in the sec-
	      tion  `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 `=' 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
	      `~'  is  doubled,	 turn  it  off.	  When this option is set, the
	      string resulting from the	expansion will	be  interpreted	 as  a
	      pattern anywhere that is possible, such as in filename expansion
	      and filename generation and pattern-matching contexts  like  the
	      right hand side of the `=' and `!=' operators in conditions.

	      In  nested  substitutions, note that the effect of the ~ applies
	      to the result of the current level of substitution.  A surround-
	      ing  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 file-
	      name  generation,	 but  ${${~foo}//\*/*.c}  substitutes  to  the
	      string *.c, which	will not be further expanded.

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

       Note  that double quotes	may appear around nested expressions, in which
       case  only  the	part  inside  is  treated  as  quoted;	for   example,
       ${(f)"$(foo)"}  quotes  the  result  of $(foo), but the flag `(f)' (see
       below) is applied using the rules for unquoted expansions.   Note  fur-
       ther that quotes	are themselves nested in this context; for example, in
       "${(@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 rep-
       etitions	need not be consecutive; for example, `(q%q%q)'	means the same
       thing as	the more readable `(%%qqq)'.  The  following  flags  are  sup-

       #      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 EXPANSION	OF PROMPT SEQUENCES in zshmisc(1)). If
	      this flag	is given twice,	full prompt expansion is done  on  the
	      resulting	words, depending on the	setting	of the PROMPT_PERCENT,
	      PROMPT_SUBST and PROMPT_BANG options.

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

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

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

       b      Quote with backslashes only characters that are special to  pat-
	      tern  matching. This is useful when the contents of the variable
	      are to be	tested using GLOB_SUBST, including the ${~...} switch.

	      Quoting  using  one  of  the q family of flags does not work for
	      this purpose since quotes	 are  not  stripped  from  non-pattern
	      characters by GLOB_SUBST.	 In other words,

		     [[	$str = ${~pattern} ]]

	      works if $str is `a*b' but not if	it is `a b', whereas

		     [[	$str = ${~pattern} ]]

	      is always	true for any possible value of $str.

       c      With ${#name}, count the total number of characters in an	array,
	      as if the	elements were concatenated with	spaces	between	 them.
	      This  is not a true join of the array, so	other expressions used
	      with this	flag may have an effect	on the elements	of  the	 array
	      before it	is counted.

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

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

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

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

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

	      Process escape sequences like the	echo builtin when  no  options
	      are  given (g::).	 With the o option, octal escapes don't	take a
	      leading zero.  With the c	option,	sequences like `^X'  are  also
	      processed.   With	 the  e	 option,  processes `\M-t' and similar
	      sequences	like the print builtin.	 With both  of	the  o	and  e
	      options,	behaves	 like the print	builtin	except that in none of
	      these modes is `\c' interpreted.

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

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

       L      Convert all letters in the result	to lower case.

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

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

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

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

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

	      Likewise,	if the reference is itself nested, the expression with
	      the  flag	 is  treated  as  if  it were directly replaced	by the
	      parameter	name.  It is an	error if this nested substitution pro-
	      duces  an	 array	with  more  than  one  word.   For example, if
	      `name=assoc' where the parameter assoc is	an associative	array,
	      then  `${${(P)name}[elt]}' refers	to the element of the associa-
	      tive subscripted `elt'.

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

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

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

       Q      Remove one level of quotes from the resulting words.

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

	      local  for local parameters

	      left   for left justified	parameters

		     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	dupli-
		     cated values

	      hide   for parameters with the `hide' flag

		     for parameters with the `hideval' 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 sub-
	      scripts,	force  values  to be substituted even if the subscript
	      form refers to indices or	keys.

       V      Make any special characters in the resulting words visible.

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

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

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

       z      Split the	result of the expansion	into words using shell parsing
	      to  find	the words, i.e.	taking into account any	quoting	in the
	      value.  Comments are  not	 treated  specially  but  as  ordinary
	      strings, similar to interactive shells with the INTERACTIVE_COM-
	      MENTS option unset (however, see the Z flag  below  for  related

	      Note  that  this	is  done  very late, even later	than the `(s)'
	      flag. So to access single	words in the result use	nested	expan-
	      sions as in `${${(z)foo}[2]}'. Likewise, to remove the quotes in
	      the resulting words use `${(Q)${(z)foo}}'.

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

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

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

	      Alternatively,  with  this option	string arguments may be	in the
	      form $var	in which case the value	of  the	 variable  is  substi-
	      tuted.   Note  this form is strict; the string argument does not
	      undergo general parameter	expansion.

	      For example,

		     print ${(ps.$sep.)val}

	      splits the variable on a :.

       ~      Strings inserted into the	expansion by any of  the  flags	 below
	      are to be	treated	as patterns.  This applies to the string argu-
	      ments of flags that follow ~ within the same set of parentheses.
	      Compare with ~ outside parentheses, which	forces the entire sub-
	      stituted string to be treated as a pattern.  Hence, for example,

		     [[	"?" = ${(~j.|.)array} ]]

	      treats  `|' as a pattern and succeeds if and only	if $array con-
	      tains the	string `?' as an element.  The ~ may  be  repeated  to
	      toggle  the  behaviour;  its effect only lasts to	the end	of the
	      parenthesised group.

	      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	 trun-
	      cated if required	and placed in a	field expr characters wide.

	      The arguments :string1: and :string2: are	optional; neither, the
	      first, or	both may be given.  Note that the same pairs of	delim-
	      iters  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 either	of string1 or string2 is present but empty, i.e. there
	      are  two	delimiters together at that point, the first character
	      of $IFS is used instead.

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

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

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

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

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

	      As l, but	pad the	words on the right and insert string2  immedi-
	      ately 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  pad-
	      ding 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.  An empty string may also be given in
	      which case every character will be a separate element.

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

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

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

	      As z but takes a combination of option letters between a follow-
	      ing pair of delimiter characters.	 With no options the effect is
	      identical	to z.  (Z+c+) causes comments to be parsed as a	string
	      and retained; any	field in the resulting array beginning with an
	      unquoted comment character is a comment.	(Z+C+) causes comments
	      to  be  parsed  and removed.  The	rule for comments is standard:
	      anything between a word starting with  the  third	 character  of
	      $HISTCHARS,  default  #,	up  to	the next newline is a comment.
	      (Z+n+) causes unquoted newlines to be treated as ordinary	white-
	      space,  else  they  are treated as if they are shell code	delim-
	      iters and	converted to semicolons.  Options are combined	within
	      the same set of delimiters, e.g. (Z+Cn+).

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

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

       S      Search  substrings  as  well as beginnings or ends; with # start
	      from the beginning and with % start from the end of the  string.
	      With  substitution  via  ${.../...}  or  ${...//...},  specifies
	      non-greedy matching, i.e.	that the shortest instead of the long-
	      est 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 substi-
	      tuted) or	${...//...} (all matches from the exprth on  are  sub-
	      stituted).  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 replace-
	      ments 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 for-
	      ward from	the start.

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

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

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

       M      Include the matched portion in the result.

       N      Include the length of the	match in the result.

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

       Here is a summary of the	rules  for  substitution;  this	 assumes  that
       braces are present around the substitution, i.e.	${...}.	 Some particu-
       lar 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 substi-
	      tution 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  substitu-
	      tion,  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

	      Note that, unless	the `(P)' flag is present, the flags  and  any
	      subscripts  apply	 directly to the value of the nested substitu-
	      tion; for	example, the expansion ${${foo}} behaves  exactly  the
	      same as ${foo}.  When the	`(P)' flag is present in a nested sub-
	      stitution, the other substitution	rules are applied to the value
	      before  it  is interpreted as a name, so ${${(P)foo}} may	differ
	      from ${(P)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	expan-
	      sion  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	 file-
	      name  expansion  to  a  full  path;  the outer substitution then
	      applies the modifier :h and takes	 the  directory	 part  of  the

       2. Internal parameter flags
	      Any  parameter  flags  set  by one of the	typeset	family of com-
	      mands, in	particular the -L, -R, -Z, -u and -l options for  pad-
	      ding  and	 capitalization, are applied directly to the parameter
	      value.  Note these flags are options to the command, e.g.	`type-
	      set  -Z';	they are not the same as the flags used	within parame-
	      ter substitutions.

	      At the outermost level of	substitution, the `(P)'	flag (rule 4.)
	      ignores  these  transformations and uses the unmodified value of
	      the parameter as the name	to be replaced.	 This is  usually  the
	      desired  behavior	 because  padding may make the value syntacti-
	      cally illegal as a parameter name, but if	capitalization changes
	      are desired, use the ${${(P)foo}}	form (rule 25.).

       3. Parameter subscripting
	      If the value is a	raw parameter reference	with a subscript, such
	      as ${var[3]}, the	effect of subscripting is applied directly  to
	      the  parameter.	Subscripts are evaluated left to right;	subse-
	      quent 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.   Flags  such  as  `(k)'  and `(v)' which alter the
	      result of	subscripting are applied.

       4. Parameter name replacement
	      At the outermost level  of  nesting  only,  the  `(P)'  flag  is
	      applied.	 This  treats  the  value  so  far as a	parameter name
	      (which may include a subscript  expression)  and	replaces  that
	      with  the	corresponding value.  This replacement occurs later if
	      the `(P)'	flag appears in	a nested substitution.

	      If the value so far names	a parameter that  has  internal	 flags
	      (rule  2.),  those  internal  flags are applied to the new value
	      after replacement.

       5. Double-quoted	joining
	      If the value after this process is an array, and	the  substitu-
	      tion  appears  in	double quotes, and neither an `(@)' flag nor a
	      `#' length operator is present at	the current level, then	 words
	      of  the value are	joined with the	first character	of the parame-
	      ter $IFS,	by default a space, between  each  word	 (single  word
	      arrays are not modified).	 If the	`(j)' flag is present, that is
	      used for joining instead of $IFS.

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

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

       8. Character evaluation
	      Any  `(#)' flag is applied, evaluating the result	so far numeri-
	      cally as a character.

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

       10. Forced joining
	      If  the  `(j)'  flag is present, or no `(j)' flag	is present but
	      the string is to be split	as given by rule 11., and joining  did
	      not  take	 place	at  rule 5., any words in the value are	joined
	      together using the given string or the first character  of  $IFS
	      if  none.	 Note that the `(F)' flag implicitly supplies a	string
	      for joining in this manner.

       11. Simple word splitting
	      If one of	the `(s)' or `(f)' flags are present, or the `=' spec-
	      ifier  was  present  (e.g. ${=var}), the word is split on	occur-
	      rences of	the specified string, or (for =	with  neither  of  the
	      two flags	present) any of	the characters in $IFS.

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

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

       13. Escape sequence replacement
	      First  any  replacements from the	`(g)' flag are performed, then
	      any prompt-style formatting from the `(%)' family	 of  flags  is

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

       15. Directory naming
	      Any directory name substitution using `(D)' flag is applied.

       16. Visibility enhancement
	      Any modifications	to make	characters  visible  using  the	 `(V)'
	      flag are applied.

       17. Lexical word	splitting
	      If  the  '(z)'  flag  or	one  of	the forms of the '(Z)' flag is
	      present, the word	is split as if it were a shell	command	 line,
	      so  that	quotation  marks  and other metacharacters are used to
	      decide what constitutes a	word.  Note this form of splitting  is
	      entirely	distinct  from that described by rule 11.: it does not
	      use $IFS,	and does not cause forced joining.

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

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

       20. RC_EXPAND_PARAM
	      At this point the	decision is made whether any  resulting	 array
	      elements	are to be combined element by element with surrounding
	      text, as given by	either the RC_EXPAND_PARAM option or  the  `^'

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

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

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

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

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

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

       25. Nested parameter name replacement
	      If the `(P)' flag	is present and rule 4. has  not	 applied,  the
	      value so far is treated as a parameter name (which may include a
	      subscript	expression) and	replaced with the corresponding	value,
	      with internal flags (rule	2.) applied to the new value.

       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.  Com-
       pare this with the effect of $(<file) alone, which divides the file  up
       by words, or the	same inside double quotes, which makes the entire con-
       tent 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 `(@)'	flag) the sub-
	      script picks the first character.

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

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

	      produces the words `a', `1 b' and	`1'.

	      produces `a', `1', `b' and `1'.

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

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

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

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

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

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

       An  expression of the form `{c1..c2}', where c1 and c2 are single char-
       acters (which may be multibyte characters), is expanded to every	 char-
       acter in	the range from c1 to c2	in whatever character sequence is used
       internally.  For	characters with	code points below 128 this is US ASCII
       (this is	the only case most users will need).  If any intervening char-
       acter is	not printable, appropriate quotation  is  used	to  render  it
       printable.   If	the  character	sequence is reversed, the output is in
       reverse order, e.g. `{d..a}' is substituted as `d c b a'.

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

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

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

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

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

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

   Dynamic named directories
       If the  function	 zsh_directory_name  exists,  or  the  shell  variable
       zsh_directory_name_functions  exists  and contains an array of function
       names, then the functions are used to implement dynamic directory  nam-
       ing.   The  functions are tried in order	until one returns status zero,
       so it is	important that functions test whether they can handle the case
       in question and return an appropriate status.

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

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

	      reply=(s 16)

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

       It  is not a requirement	that a function	implements both	n and d	calls;
       for example, it might be	 appropriate  for  certain  dynamic  forms  of
       expansion  not  to  be contracted to names.  In that case any call with
       the first argument d should cause a non-zero status to be returned.

       The completion system calls `zsh_directory_name c' followed by  equiva-
       lent calls to elements of the array zsh_directory_name_functions, if it
       exists, in order	to complete dynamic names for directories.   The  code
       for this	should be as for any other completion function as described in

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

	      zsh_directory_name() {
		emulate	-L zsh
		setopt extendedglob
		local -a match mbegin mend
		if [[ $1 = d ]]; then
		  # turn the directory into a name
		  if [[	$2 = (#b)(/home/pws/perforce/)([^/]##)*	]]; then
		    typeset -ga	reply
		    reply=(p:$match[2] $(( ${#match[1]}	+ ${#match[2]} )) )
		    return 1
		elif [[	$1 = n ]]; then
		  # turn the name into a directory
		  [[ $2	!= (#b)p:(?*) ]] && return 1
		  typeset -ga reply
		elif [[	$1 = c ]]; then
		  # complete names
		  local	expl
		  local	-a dirs
		  _wanted dynamic-dirs expl 'dynamic directory'	compadd	-S\] -a	dirs
		  return 1
		return 0

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

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

       When the	shell prints a path (e.g. when expanding %~ in prompts or when
       printing	 the  directory	stack),	the path is checked to see if it has a
       named directory as its prefix.  If  so,	then  the  prefix  portion  is
       replaced	with a `~' followed by the name	of the directory.  The shorter
       of the two ways of referring to the directory is	used, i.e. either  the
       directory  name or the full path; the name is used if they are the same
       length.	The parameters $PWD and	$OLDPWD	are never abbreviated in  this

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

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

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

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

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

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

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

       ?      Matches any character.

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

		     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	white-

		     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  identi-
		     fier, 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.

		     Matches  a	byte that starts an incomplete multibyte char-
		     acter.  Note that there may be a sequence	of  more  than
		     one bytes that taken together form	the prefix of a	multi-
		     byte character.  To test  for  a  potentially  incomplete
		     byte sequence, use	the pattern `[[:INCOMPLETE:]]*'.  This
		     will never	match a	sequence starting with a valid	multi-
		     byte character.

		     Matches  a	 byte  that  does  not start a valid multibyte
		     character.	 Note this may be a continuation  byte	of  an
		     incomplete	multibyte character as any part	of a multibyte
		     string consisting of  invalid  and	 incomplete  multibyte
		     characters	is treated as single bytes.

		     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 alphanu-
	      meric character you need `[[:alnum:]]'.	Named  character  sets
	      can be used alongside other types, e.g. `[[:alpha:]0-9]'.

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

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

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

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

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

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

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

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

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

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

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

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

       *(...) Match  any  number  of occurrences.  (Like `(...)#', except that
	      recursive	directory searching is not supported.)

       +(...) Match at least one occurrence.   (Like  `(...)##',  except  that
	      recursive	directory searching is not supported.)

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

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

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

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

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

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

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

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

	      For example,

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

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

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

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

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

	      Pattern matching with backreferences  is	slightly  slower  than

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

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

       m      Set  references to the match data	for the	entire string matched;
	      this is similar to backreferencing and does not work in filename
	      generation.   The	 flag must be in effect	at the end of the pat-
	      tern, 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,	print-
	      ing `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:  `(#s)' and `(#e)' are	the only valid
	      forms.  The `(#s)' flag succeeds only at the start of  the  test
	      string, and the `(#e)' flag succeeds only	at the end of the test
	      string; they correspond to  `^'  and  `$'	 in  standard  regular
	      expressions.  They are useful for	matching path segments in pat-
	      terns other than those in	filename generation (where  path  seg-
	      ments  are  in  any  case	 treated  separately).	 For  example,
	      `*((#s)|/)test((#e)|/)*' matches a path segment `test' in	any of
	      the   following	strings:   test,  test/at/start,  at/end/test,

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

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

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

       u      Respect the current locale in determining	the presence of	multi-
	      byte  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  charac-
       ters  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 char-
       acter).	 Similarly,  errors  are counted separately for	non-contiguous
       strings in the pattern, so that (ab|cd)ef is two	errors from aebf.

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

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

       Entire	path   segments	  may	be   matched  approximately,  so  that
       `(#a1)/foo/d/is/available/at/the/bar' allows one	error in any path seg-
       ment.   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 seg-
       ments which are known to	be correct.

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

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

	      ls (*/)#bar


	      ls **/bar

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

       Even shorter forms are available	when  the  option  GLOB_STAR_SHORT  is
       set.   In  that	case  if no / immediately follows a ** or *** they are
       treated as if both a / plus a further * are present.  Hence:

	      setopt GLOBSTARSHORT
	      ls **.c

       is equivalent to

	      ls **/*.c

   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 `|' or `('	characters (or `~' if it is special) is	 taken
       as  a set of glob qualifiers.  A	glob subexpression that	would normally
       be taken	as glob	qualifiers, for	example	`(^x)',	can be	forced	to  be
       treated	as  part  of  the glob pattern by doubling the parentheses, in
       this case producing `((^x))'.

       If the option EXTENDED_GLOB is set, a different syntax for glob	quali-
       fiers  is  available,  namely  `(#qx)'  where x is any of the same glob
       qualifiers used in the other format.  The qualifiers must still	appear
       at  the	end  of	 the pattern.  However,	with this syntax multiple glob
       qualifiers may be chained together.  They are treated as	a logical  AND
       of  the	individual sets	of flags.  Also, as the	syntax is unambiguous,
       the expression will be treated as glob  qualifiers  just	 as  long  any
       parentheses contained within it are balanced; appearance	of `|',	`(' or
       `~' does	not negate the effect.	Note that qualifiers  will  be	recog-
       nised  in  this form even if a bare glob	qualifier exists at the	end of
       the pattern, for	example	`*(#q*)(.)' will recognise executable  regular
       files if	both options are set; however, mixed syntax should probably be
       avoided for the sake of clarity.	 Note that within conditions using the
       `[[' form the presence of a parenthesised expression (#q...) at the end
       of a string indicates that globbing should be performed;	the expression
       may include glob	qualifiers, but	it is also valid if it is simply (#q).
       This does not apply to the right	hand side of pattern  match  operators
       as the syntax already has special significance.

       A qualifier may be any one of the following:

       /      directories

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

       .      plain files

       @      symbolic links

       =      sockets

       p      named pipes (FIFOs)

       *      executable plain files (0100 or 0010 or 0001)

       %      device files (character or block special)

       %b     block special files

       %c     character	special	files

       r      owner-readable files (0400)

       w      owner-writable files (0200)

       x      owner-executable files (0100)

       A      group-readable files (0040)

       I      group-writable files (0020)

       E      group-executable files (0010)

       R      world-readable files (0004)

       W      world-writable files (0002)

       X      world-executable files (0001)

       s      setuid files (04000)

       S      setgid files (02000)

       t      files with the sticky bit	(01000)

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

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

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

       +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 sta-
	      tus (usually the status of the last command).

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

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

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

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

       gid    like uid but with	group IDs or names

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

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

	      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 size specifier `k'	(`K'),
	      `m'  (`M'),  or  `p' (`P') (e.g. `Lk-50')	the check is performed
	      with kilobytes, megabytes, or blocks  (of	 512  bytes)  instead.
	      (On  some	 systems additional specifiers are available for giga-
	      bytes, `g' or `G', and terabytes,	`t' or `T'.) If	a size	speci-
	      fier  is	used  a	 file is regarded as "exactly" the size	if the
	      file size	rounded	up to the next unit is equal to	the test size.
	      Hence `*(Lm1)' matches files from	1 byte up to 1 Megabyte	inclu-
	      sive.  Note also that the	set of files "less than" the test size
	      only  includes  files  that  would  not match the	equality test;
	      hence `*(Lm-1)' only matches files of zero size.

       ^      negates all qualifiers following it

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

       M      sets the MARK_DIRS option	for the	current	pattern

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

       N      sets the NULL_GLOB option	for the	current	pattern

       D      sets the GLOB_DOTS option	for the	current	pattern

       n      sets the NUMERIC_GLOB_SORT option	for the	current	pattern

       Yn     enables short-circuit mode: the pattern will expand to at	most n
	      filenames.   If  more  than  n  matches  exist, only the first n
	      matches in directory traversal order will	be considered.

	      Implies oN when no oc qualifier is used.

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

	      The default sorting is n (by name) unless	the Y  glob  qualifier
	      is used, in which	case it	is N (unsorted).

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

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

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

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

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

	      If the modifier ^	 is  active,  then  string  will  be  appended
	      instead of prepended.  Prepending	and appending is done indepen-
	      dently so	both can be used on  the  same	glob  expression;  for
	      example  by writing `*(P:foo:^P:bar:^P:baz:)' which produces the
	      command line arguments `foo baz file1 bar	...'

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

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

	      ls *(-/)

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

	      ls *(-@)

       lists all broken	symbolic links,	and

	      ls *(%W)

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

	      ls *(W,X)

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

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

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

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

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

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

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

zsh 5.2			       December	2, 2015			    ZSHEXPN(1)


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