| .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
| .\" |
| .\" %%%LICENSE_START(VERBATIM) |
| .\" Permission is granted to make and distribute verbatim copies of this |
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| .\" manual under the conditions for verbatim copying, provided that the |
| .\" entire resulting derived work is distributed under the terms of a |
| .\" permission notice identical to this one. |
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| .\" Since the Linux kernel and libraries are constantly changing, this |
| .\" manual page may be incorrect or out-of-date. The author(s) assume no |
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| .\" References consulted: |
| .\" Linux libc source code |
| .\" 386BSD man pages |
| .\" Modified Sat Jul 24 18:50:48 1993 by Rik Faith (faith@cs.unc.edu) |
| .\" Interchanged 'needle' and 'haystack'; added history, aeb, 980113. |
| .TH MEMMEM 3 2016-07-17 "GNU" "Linux Programmer's Manual" |
| .SH NAME |
| memmem \- locate a substring |
| .SH SYNOPSIS |
| .nf |
| .BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */" |
| .B #include <string.h> |
| .sp |
| .BI "void *memmem(const void *" haystack ", size_t " haystacklen , |
| .BI " const void *" needle ", size_t " needlelen ); |
| .fi |
| .SH DESCRIPTION |
| The |
| .BR memmem () |
| function finds the start of the first occurrence |
| of the substring |
| .IR needle |
| of length |
| .I needlelen |
| in the memory |
| area |
| .I haystack |
| of length |
| .IR haystacklen . |
| .SH RETURN VALUE |
| The |
| .BR memmem () |
| function returns a pointer to the beginning of the |
| substring, or NULL if the substring is not found. |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .TS |
| allbox; |
| lb lb lb |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR memmem () |
| T} Thread safety MT-Safe |
| .TE |
| .SH CONFORMING TO |
| This function is not specified in POSIX.1, |
| but is present on a number of other systems. |
| .SH BUGS |
| .\" This function was broken in Linux libraries up to and including libc 5.0.9; |
| .\" there the |
| .\" .IR needle |
| .\" and |
| .\" .I haystack |
| .\" arguments were interchanged, |
| .\" and a pointer to the end of the first occurrence of |
| .\" .I needle |
| .\" was returned. |
| .\" |
| .\" Both old and new libc's have the bug that if |
| .\" .I needle |
| .\" is empty, |
| .\" .I haystack\-1 |
| .\" (instead of |
| .\" .IR haystack ) |
| .\" is returned. |
| In glibc 2.0, if |
| .I needle |
| is empty, |
| .BR memmem () |
| returns a pointer to the last byte of |
| .IR haystack . |
| This is fixed in glibc 2.1. |
| .SH SEE ALSO |
| .BR strstr (3) |