MEMMEM(3) FreeBSD Library Functions Manual MEMMEM(3)
NAME
memmem - locate a byte substring in a byte string
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <string.h>
void *
memmem(const void *big, size_t big_len, const void *little,
size_t little_len);
DESCRIPTION
The memmem() function locates the first occurrence of the byte string
little in the byte string big.
RETURN VALUES
If little_len is zero big is returned (that is, an empty little is deemed
to match at the beginning of big); if little occurs nowhere in big, NULL
is returned; otherwise a pointer to the first character of the first
occurrence of little is returned.
SEE ALSO
memchr(3), strchr(3), strstr(3)
STANDARDS
memmem() conforms to.
HISTORY
The memmem() function first appeared in FreeBSD 6.0. It was replaced
with an optimized O(n) implementation from the musl libc project in
FreeBSD 12.0. Pascal Gloor <
[email protected]> provided this man
page along with the previous implementation.
BUGS
This function was broken in Linux libc up to and including version 5.0.9
and in GNU libc prior to version 2.1. Prior to FreeBSD 11.0 memmem
returned NULL when little_len equals 0.
FreeBSD 14.1-RELEASE-p8 June 29, 2023 FreeBSD 14.1-RELEASE-p8