COMMENT(!MOD!zsh/pcre
Interface to the PCRE library.
!MOD!)
cindex(regular expressions, perl-compatible)
The tt(zsh/pcre) module makes some commands available as builtins:

startitem()
findex(pcre_compile)
item(tt(pcre_compile) [ tt(-aimx) ] var(PCRE))(
Compiles a perl-compatible regular expression.

Option tt(-a) will force the pattern to be anchored.
Option tt(-i) will compile a case-insensitive pattern.
Option tt(-m) will compile a multi-line pattern; that is,
tt(^) and tt($) will match newlines within the pattern.
Option tt(-x) will compile an extended pattern, wherein
whitespace and tt(#) comments are ignored.
)
findex(pcre_study)
item(tt(pcre_study))(
Studies the previously-compiled PCRE which may result in faster
matching.
)
findex(pcre_match)
item(tt(pcre_match) [ tt(-v) var(var) ] [ tt(-a) var(arr) ] var(string))(
Returns successfully if tt(string) matches the previously-compiled
PCRE.

Upon successful match,
if the expression captures substrings within parentheses,
tt(pcre_match) will set the array var($match) to those
substrings, unless the tt(-a) option is given, in which
case it will set the array var(arr).  Similarly, the variable
var(MATCH) will be set to the entire matched portion of the
string, unless the tt(-v) option is given, in which case the variable
var(var) will be set.
No variables are altered if there is no successful match.
)
enditem()

The tt(zsh/pcre) module makes available the following test condition:
startitem()
findex(pcre-match)
item(expr tt(-pcre-match) pcre)(
Matches a string against a perl-compatible regular expression.

For example,

[[ "$text" -pcre-match ^d+$ ]] && print text variable contains only "d's".
)
enditem()