strstr, strcasestr - locate a substring
Standard C library (
libc,
-lc)
#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);
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.
These functions return a pointer to the beginning of the located substring, or
NULL if the substring is not found.
If
needle is the empty string, the return value is always
haystack
itself.
For an explanation of the terms used in this section, see
attributes(7).
Interface |
Attribute |
Value |
strstr () |
Thread safety |
MT-Safe |
strcasestr () |
Thread safety |
MT-Safe locale |
strstr(): POSIX.1-2001, POSIX.1-2008, C99.
The
strcasestr() function is a nonstandard extension.
memchr(3),
memmem(3),
strcasecmp(3),
strchr(3),
string(3),
strpbrk(3),
strsep(3),
strspn(3),
strtok(3),
wcsstr(3)