NAME    [Toc]    [Back]

       memmem - locate a substring

SYNOPSIS    [Toc]    [Back]

       #define _GNU_SOURCE
       #include <string.h>

       void *memmem(const void *haystack, size_t haystacklen,
	      const void *needle, size_t needlelen);

DESCRIPTION    [Toc]    [Back]

       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    [Toc]    [Back]

       The  memmem()  function	returns a pointer to the beginning of the substring,
 or NULL if the substring is not found.

CONFORMING TO    [Toc]    [Back]

       This function is a GNU extension.

BUGS    [Toc]    [Back]

       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 ALSO    [Toc]    [Back]

       strstr(3)



GNU				  1998-01-13			     MEMMEM(3)