memmem - locate a substring
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <string.h>
void *memmem(const void haystack[.haystacklen], size_t haystacklen,
const void needle[.needlelen], size_t needlelen);
The memmem() function finds the start of the first
occurrence of the substring needle
of length needlelen
in the memory area haystack
of length haystacklen
.
The memmem() function returns a pointer to the beginning of the substring, or NULL if the substring is not found.