MEMMEM(3) Linux Programmer's Manual MEMMEM(3)NAMEmemmem - locate a substring
SYNOPSIS
#define _GNU_SOURCE
#include <string.h>
void *memmem(const void *haystack, size_t haystacklen,
const void *needle, size_t needlelen);
DESCRIPTION
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.
RETURN VALUE
The memmem() function returns a pointer to the beginning of the sub‐
string, or NULL if the substring is not found.
CONFORMING TO
This function is a GNU extension.
BUGS
This function was broken in Linux libraries up to and including libc
5.0.9; there the `needle' and `haystack' arguments were interchanged,
and a pointer to the end of the first occurrence of needle was
returned. Since libc 5.0.9 is still widely used, this is a dangerous
function to use.
Both old and new libc's have the bug that if needle is empty haystack-1
(instead of haystack) is returned. And glibc 2.0 makes it worse, and
returns a pointer to the last byte of `haystack'. This is fixed in
glibc 2.1.
SEE ALSOstrstr(3)GNU 1998-01-13 MEMMEM(3)
