NAME¶
strstr, strcasestr - locate a substring
SYNOPSIS¶
#include <string.h>
char *strstr(const char *haystack, const char *needle);
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <string.h>
char *strcasestr(const char *haystack, const char *needle);
DESCRIPTION¶
The
strstr() function finds the first occurrence of the substring
needle in the string
haystack. The terminating null bytes ('\0')
are not compared.
The
strcasestr() function is like
strstr(), but ignores the case
of both arguments.
RETURN VALUE¶
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 nonstandard extension.
BUGS¶
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.
SEE ALSO¶
index(3),
memchr(3),
rindex(3),
strcasecmp(3),
strchr(3),
string(3),
strpbrk(3),
strsep(3),
strspn(3),
strtok(3),
wcsstr(3)
COLOPHON¶
This page is part of release 3.44 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/.