memmem(3) — Linux manual page

memmem(3)               Library Functions Manual               memmem(3)

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

       None.

HISTORY

       musl libc 0.9.7; FreeBSD 6.0, OpenBSD 5.4, NetBSD, 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.

SEE ALSO

       bstring(3), strstr(3)

COLOPHON

       This page is part of the man-pages (Linux kernel and C library
       user-space interface documentation) project.  Information about
       the project can be found at 
       ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report
       for this manual page, see
       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
       This page was obtained from the tarball man-pages-6.9.1.tar.gz
       fetched from
       ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
       2024-06-26.  If you discover any rendering problems in this HTML
       version of the page, or you believe there is a better or more up-
       to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not
       part of the original manual page), send a mail to
       man-pages@man7.org

Linux man-pages 6.9.1          2024-05-02                      memmem(3)

Pages that refer to this page: bstring(3), memchr(3), strstr(3)

---