NAME

memmem - locate a substring

LIBRARY

Standard C library (libc, -lc)

SYNOPSIS

#define _GNU_SOURCE         /* See feature_test_macros(7) */
#include <string.h>

void *memmem(const void haystack[.haystacklen], size_t haystacklen,
             const void needle[.needlelen], 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.

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).

Interface	Attribute	Value
memmem ()	Thread safety	MT-Safe

STANDARDS

This function is not specified in POSIX.1, but is present on a number of other systems, including: musl libc 0.9.7; FreeBSD 6.0, OpenBSD 5.4, NetBSD, and Illumos.

BUGS

In glibc 2.0, if needle is empty, memmem() returns a pointer to the last byte of haystack. This is fixed in glibc 2.1.