NAME

       PCRE2 - Perl-compatible regular expressions (revised API)

SYNOPSIS

       #include <pcre2.h>

       int pcre2_callout_enumerate(const pcre2_code *code,
         int (*callback)(pcre2_callout_enumerate_block *, void *),
         void *callout_data);

DESCRIPTION

       This  function  scans  a compiled regular expression and calls the callback() function for
       each callout within the pattern. The yield of the function is zero for  success  and  non-
       zero otherwise. The arguments are:

         code           Points to the compiled pattern
         callback       The callback function
         callout_data   User data that is passed to the callback

       The  callback()  function  is  passed  a  pointer to a data block containing the following
       fields (not necessarily in this order):

         uint32_t   version                Block version number
         uint32_t   callout_number         Number for numbered callouts
         PCRE2_SIZE pattern_position       Offset to next item in pattern
         PCRE2_SIZE next_item_length       Length of next item in pattern
         PCRE2_SIZE callout_string_offset  Offset to string within pattern
         PCRE2_SIZE callout_string_length  Length of callout string
         PCRE2_SPTR callout_string         Points to callout string or is NULL

       The second argument passed to the callback() function is the callout data that was  passed
       to  pcre2_callout_enumerate().  The  callback() function must return zero for success. Any
       other value causes the pattern scan to stop, with the  value  being  passed  back  as  the
       result of pcre2_callout_enumerate().

       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.