MEMMEM(3)		   Linux Programmers Manual		    MEMMEM(3)



NAME
       memmem - locate a substring

SYNOPSIS
       #define _GNU_SOURCE
       #include 

       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 libcs 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 ALSO
       strstr(3), feature_test_macros(7)

COLOPHON
       This  page  is  part of release 3.05 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				  1998-01-13			     MEMMEM(3)