strstr, strcasestr — locate a substring
#include <string.h>
char
*strstr( |
const char * | haystack, |
const char * | needle) ; |
#define _GNU_SOURCE #include <string.h>
char
*strcasestr( |
const char * | haystack, |
const char * | needle) ; |
The strstr
() function finds
the first occurrence of the substring needle
in the string haystack
. The terminating '\0'
characters are not compared.
The strcasestr
() function is
like strstr
(), but ignores the
case of both arguments.
These functions return a pointer to the beginning of the substring, or NULL if the substring is not found.
The strstr
() function
conforms to C89 and C99. The strcasestr
() function is a non-standard
extension.
Early versions of Linux libc (like 4.5.26) would not allow
an empty needle
argument for strstr
(). Later
versions (like 4.6.27) work correctly, and return haystack
when needle
is empty.
index(3), memchr(3), rindex(3), strchr(3), strcasecmp(3), strpbrk(3), strsep(3), strspn(3), strtok(3), wcsstr(3), feature_test_macros(7)
This page is part of release 2.79 of the Linux man-pages
project. A
description of the project, and information about reporting
bugs, can be found at
http://www.kernel.org/doc/man-pages/.
Copyright 1993 David Metcalfe (davidprism.demon.co.uk) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this 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. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. References consulted: Linux libc source code Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) 386BSD man pages Modified Sat Jul 24 17:56:43 1993 by Rik Faith (faithcs.unc.edu) Added history, aeb, 980113. 2005-05-05 mtk: added strcasestr() |