NAME
memmem - locate a substring SYNOPSIS
#define GNUSOURCE /* See featuretestmacros(7) */
#include
void *memmem(const void *haystack, sizet haystacklen, const void *needle, sizet 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. ATTRIBUTES For an explanation of the terms used in this section, see attributes(7). ┌──────────┬───────────────┬─────────┐ │Interface │ Attribute │ Value │ ├──────────┼───────────────┼─────────┤ │memmem() │ Thread safety │ MT-Safe │ └──────────┴───────────────┴─────────┘ 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. 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. SEE ALSO strstr(3) COLOPHON
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/.
GNU 2008-12-05 MEMMEM(3)