pcre_fullinfo (3)

#include <pcre.h>

int pcre_fullinfo(const pcre *code, const pcre_extra *extra,
     int what, void *where);

int pcre16_fullinfo(const pcre16 *code, const pcre16_extra *extra,
     int what, void *where);

int pcre32_fullinfo(const pcre32 *code, const pcre32_extra *extra,
     int what, void *where);

This function returns information about a compiled pattern. Its arguments are:

  code                      Compiled regular expression
  extra                     Result of pcre[16|32]_study() or NULL
  what                      What information is required
  where                     Where to put the information

The following information is available:

  PCRE_INFO_BACKREFMAX      Number of highest back reference
  PCRE_INFO_CAPTURECOUNT    Number of capturing subpatterns
  PCRE_INFO_DEFAULT_TABLES  Pointer to default tables
  PCRE_INFO_FIRSTBYTE       Fixed first data unit for a match, or
                              -1 for start of string
                                 or after newline, or
                              -2 otherwise
  PCRE_INFO_FIRSTTABLE      Table of first data units (after studying)
  PCRE_INFO_HASCRORLF       Return 1 if explicit CR or LF matches exist
  PCRE_INFO_JCHANGED        Return 1 if (?J) or (?-J) was used
  PCRE_INFO_JIT             Return 1 after successful JIT compilation
  PCRE_INFO_JITSIZE         Size of JIT compiled code
  PCRE_INFO_LASTLITERAL     Literal last data unit required
  PCRE_INFO_MINLENGTH       Lower bound length of matching strings
  PCRE_INFO_NAMECOUNT       Number of named subpatterns
  PCRE_INFO_NAMEENTRYSIZE   Size of name table entry
  PCRE_INFO_NAMETABLE       Pointer to name table
  PCRE_INFO_OKPARTIAL       Return 1 if partial matching can be tried
                              (always returns 1 after release 8.00)
  PCRE_INFO_OPTIONS         Option bits used for compilation
  PCRE_INFO_SIZE            Size of compiled pattern
  PCRE_INFO_STUDYSIZE       Size of study data
  PCRE_INFO_FIRSTCHARACTER      Fixed first data unit for a match
  PCRE_INFO_FIRSTCHARACTERFLAGS Returns
                                  1 if there is a first data character set, which can
                                    then be retrieved using PCRE_INFO_FIRSTCHARACTER,
                                  2 if the first character is at the start of the data
                                    string or after a newline, and
                                  0 otherwise
  PCRE_INFO_REQUIREDCHAR      Literal last data unit required
  PCRE_INFO_REQUIREDCHARFLAGS Returns 1 if the last data character is set (which can then
                              be retrieved using PCRE_INFO_REQUIREDCHAR); 0 otherwise

The where argument must point to an integer variable, except for the following what values:

  PCRE_INFO_DEFAULT_TABLES  const unsigned char *
  PCRE_INFO_FIRSTTABLE      const unsigned char *
  PCRE_INFO_NAMETABLE       PCRE_SPTR16           (16-bit library)
  PCRE_INFO_NAMETABLE       PCRE_SPTR32           (32-bit library)
  PCRE_INFO_NAMETABLE       const unsigned char * (8-bit library)
  PCRE_INFO_OPTIONS         unsigned long int
  PCRE_INFO_SIZE            size_t
  PCRE_INFO_FIRSTCHARACTER  uint32_t
  PCRE_INFO_REQUIREDCHAR    uint32_t

The yield of the function is zero on success or:

  PCRE_ERROR_NULL           the argument code was NULL
                            the argument where was NULL
  PCRE_ERROR_BADMAGIC       the "magic number" was not found
  PCRE_ERROR_BADOPTION      the value of what was invalid

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.