MEMMEM(3)                                           Linux Programmer's Manual                                          MEMMEM(3)



NAME
       memmem - 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 substring, 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.

       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), feature_test_macros(7)

COLOPHON
       This page is part of release 3.25 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)