PCRE_COMPILE(3)

🌸 NAME 🌸

hii bestie, welcome to PCRE_COMPILE(3), hanging out under the Library Functions Manual umbrella 💖 this whole page is about PCRE — that's Perl-compatible regular expressions — and no cap, it's iconic.

✨ SYNOPSIS ✨

#include <pcre.h>

pcre *pcre_compile(const char *pattern, int options,
     const char **errptr, int *erroffset,
     const unsigned char *tableptr);

pcre16 *pcre16_compile(PCRE_SPTR16 pattern, int options,
     const char **errptr, int *erroffset,
     const unsigned char *tableptr);

pcre32 *pcre32_compile(PCRE_SPTR32 pattern, int options,
     const char **errptr, int *erroffset,
     const unsigned char *tableptr);

💅 DESCRIPTION 💅

okay so, what this function does is compile a regular expression into an internal form ✨ it is literally the same as pcre[16|32]_compile2(), with exactly one difference: there's no errorcodeptr argument. that's it, that's the whole tea 🍓

the arguments are giving very much:

• pattern — a zero-terminated string containing the regular expression to be compiled
• options — zero or more option bits
• errptr — where to put an error message
• erroffset — offset in pattern where error was found
• tableptr — pointer to character tables, or NULL to use the built-in default

👑 the option bits 👑

these are the little flags you can OR together, and every single one of them matters, so buckle up:

• PCRE_ANCHORED — force pattern anchoring
• PCRE_AUTO_CALLOUT — compile automatic callouts
• PCRE_BSR_ANYCRLF — \R matches only CR, LF, or CRLF
• PCRE_BSR_UNICODE — \R matches all Unicode line endings
• PCRE_CASELESS — do caseless matching
• PCRE_DOLLAR_ENDONLY — $ not to match newline at end
• PCRE_DOTALL — . matches anything including NL
• PCRE_DUPNAMES — allow duplicate names for subpatterns
• PCRE_EXTENDED — ignore white space and # comments
• PCRE_EXTRA — PCRE extra features (not much use currently)
• PCRE_FIRSTLINE — force matching to be before newline
• PCRE_JAVASCRIPT_COMPAT — JavaScript compatibility
• PCRE_MULTILINE — ^ and $ match newlines within data
• PCRE_NEVER_UTF — lock out UTF, e.g. via (*UTF)
• PCRE_NEWLINE_ANY — recognize any Unicode newline sequence
• PCRE_NEWLINE_ANYCRLF — recognize CR, LF, and CRLF as newline sequences
• PCRE_NEWLINE_CR — set CR as the newline sequence
• PCRE_NEWLINE_CRLF — set CRLF as the newline sequence
• PCRE_NEWLINE_LF — set LF as the newline sequence
• PCRE_NO_AUTO_CAPTURE — disable numbered capturing parentheses (named ones available)
• PCRE_NO_AUTO_POSSESS — disable auto-possessification
• PCRE_NO_START_OPTIMIZE — disable match-time start optimizations
• PCRE_NO_UTF16_CHECK — do not check the pattern for UTF-16 validity (only relevant if PCRE_UTF16 is set)
• PCRE_NO_UTF32_CHECK — do not check the pattern for UTF-32 validity (only relevant if PCRE_UTF32 is set)
• PCRE_NO_UTF8_CHECK — do not check the pattern for UTF-8 validity (only relevant if PCRE_UTF8 is set)
• PCRE_UCP — use Unicode properties for \d, \w, etc.
• PCRE_UNGREEDY — invert greediness of quantifiers
• PCRE_UTF16 — run in pcre16_compile() UTF-16 mode
• PCRE_UTF32 — run in pcre32_compile() UTF-32 mode
• PCRE_UTF8 — run in pcre_compile() UTF-8 mode

🫶 real talk though: PCRE must be built with UTF support in order to use PCRE_UTF8/16/32 and PCRE_NO_UTF8/16/32_CHECK, and with UCP support if PCRE_UCP is used. no build flag, no vibes, no exceptions.

🌈 what you get back 🌈

the yield of the function is a pointer to a private data structure that contains the compiled pattern, or NULL if an error was detected 👑

💀 and listen: compiling regular expressions with one version of PCRE for use with a different version is not guaranteed to work and may cause crashes. that's not a vibe check you want to fail, bestie. fr fr.

also, for the record: there is a complete description of the PCRE native API in the pcreapi page, and a description of the POSIX API in the pcreposix page 🌸 go read those next, iykyk.

and that's the whole page, periodt 🎀 this was PCRE_COMPILE(3) from PCRE 8.34, dated 01 October 2013 — mwah, go compile something beautiful 💖✨