memmem − locate a substring
_GNU_SOURCE /* See feature_test_macros(7) */
*memmem(const void *haystack, size_t
const void *needle, 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.
For an explanation of the terms used in this section, see attributes(7).
This function is a GNU extension.
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.
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, returning a pointer to the last byte of haystack. This is fixed in glibc 2.1.
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man−pages/.