NAME

       PCRE2 - Perl-compatible regular expressions (revised API)

SYNOPSIS

       #include <pcre2.h>

       int pcre2_pattern_info(const pcre2 *code, uint32_t what, void *where);

DESCRIPTION

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

         code     Pointer to a compiled regular expression
         what     What information is required
         where    Where to put the information

       The  recognized  values  for  the  what  argument, and the information they request are as
       follows:

         PCRE2_INFO_ALLOPTIONS      Final options after compiling
         PCRE2_INFO_ARGOPTIONS      Options passed to pcre2_compile()
         PCRE2_INFO_BACKREFMAX      Number of highest back reference
         PCRE2_INFO_BSR             What \R matches:
                                      PCRE2_BSR_UNICODE: Unicode line endings
                                      PCRE2_BSR_ANYCRLF: CR, LF, or CRLF only
         PCRE2_INFO_CAPTURECOUNT    Number of capturing subpatterns
         PCRE2_INFO_FIRSTBITMAP     Bitmap of first code units, or NULL
         PCRE2_INFO_FIRSTCODETYPE   Type of start-of-match information
                                      0 nothing set
                                      1 first code unit is set
                                      2 start of string or after newline
         PCRE2_INFO_FIRSTCODEUNIT   First code unit when type is 1
         PCRE2_INFO_HASBACKSLASHC   Return 1 if pattern contains \C
         PCRE2_INFO_HASCRORLF       Return 1 if explicit CR or LF matches
                                      exist in the pattern
         PCRE2_INFO_JCHANGED        Return 1 if (?J) or (?-J) was used
         PCRE2_INFO_JITSIZE         Size of JIT compiled code, or 0
         PCRE2_INFO_LASTCODETYPE    Type of must-be-present information
                                      0 nothing set
                                      1 code unit is set
         PCRE2_INFO_LASTCODEUNIT    Last code unit when type is 1
         PCRE2_INFO_MATCHEMPTY      1 if the pattern can match an
                                      empty string, 0 otherwise
         PCRE2_INFO_MATCHLIMIT      Match limit if set,
                                      otherwise PCRE2_ERROR_UNSET
         PCRE2_INFO_MAXLOOKBEHIND   Length (in characters) of the longest
                                      lookbehind assertion
         PCRE2_INFO_MINLENGTH       Lower bound length of matching strings
         PCRE2_INFO_NAMECOUNT       Number of named subpatterns
         PCRE2_INFO_NAMEENTRYSIZE   Size of name table entries
         PCRE2_INFO_NAMETABLE       Pointer to name table
         PCRE2_CONFIG_NEWLINE       Code for the newline sequence:
                                      PCRE2_NEWLINE_CR
                                      PCRE2_NEWLINE_LF
                                      PCRE2_NEWLINE_CRLF
                                      PCRE2_NEWLINE_ANY
                                      PCRE2_NEWLINE_ANYCRLF
         PCRE2_INFO_RECURSIONLIMIT  Recursion limit if set,
                                      otherwise PCRE2_ERROR_UNSET
         PCRE2_INFO_SIZE            Size of compiled pattern

       If where is NULL, the function returns the amount  of  memory  needed  for  the  requested
       information,  in  bytes.  Otherwise,  the  where argument must point to an unsigned 32-bit
       integer (uint32_t variable), except for the following what values, when it must point to a
       variable of the type shown:

         PCRE2_INFO_FIRSTBITMAP     const uint8_t *
         PCRE2_INFO_JITSIZE         size_t
         PCRE2_INFO_NAMETABLE       PCRE2_SPTR
         PCRE2_INFO_SIZE            size_t

       The yield of the function is zero on success or:

         PCRE2_ERROR_NULL           the argument code is NULL
         PCRE2_ERROR_BADMAGIC       the "magic number" was not found
         PCRE2_ERROR_BADOPTION      the value of what is invalid
         PCRE2_ERROR_BADMODE        the pattern was compiled in the wrong mode
         PCRE2_ERROR_UNSET          the requested information is not set

       There  is  a  complete  description  of  the  PCRE2  native API in the pcre2api page and a
       description of the POSIX API in the pcre2posix page.