strstr(3) BSD Library Functions Manual strstr(3)
NAME
strstr, strcasestr, strnstr -- locate a substring in a string
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <string.h>
char *
strstr(const char *haystack, const char *needle);
char *
strcasestr(const char *haystack, const char *needle);
char *
strnstr(const char *haystack, const char *needle, size_t len);
#include <string.h>
#include <xlocale.h>
char *
strcasestr_l(const char *haystack, const char *needle, locale_t loc);
DESCRIPTION
The strstr() function locates the first occurrence of the null-terminated
string needle in the null-terminated string haystack.
The strcasestr() function is similar to strstr(), but ignores the case of
both strings.
The strnstr() function locates the first occurrence of the null-termi-
nated string needle in the string haystack, where not more than len char-
acters are searched. Characters that appear after a `\0' character are
not searched. Since the strnstr() function is a FreeBSD specific API, it
should only be used when portability is not a concern.
While the strcasestr() function uses the current locale, the
strcasestr_l() function may be passed a locale directly. See xlocale(3)
for more information.
RETURN VALUES
If needle is an empty string, haystack is returned; if needle occurs
nowhere in haystack, NULL is returned; otherwise a pointer to the first
character of the first occurrence of needle is returned.
EXAMPLES
The following sets the pointer ptr to the "Bar Baz" portion of
largestring:
const char *largestring = "Foo Bar Baz";
const char *smallstring = "Bar";
char *ptr;
ptr = strstr(largestring, smallstring);
The following sets the pointer ptr to NULL, because only the first 4
characters of largestring are searched:
const char *largestring = "Foo Bar Baz";
const char *smallstring = "Bar";
char *ptr;
ptr = strnstr(largestring, smallstring, 4);
SEE ALSO
memchr(3), memmem(3), strchr(3), strcspn(3), strpbrk(3), strrchr(3),
strsep(3), strspn(3), strtok(3), wcsstr(3), xlocale(3)
STANDARDS
The strstr() function conforms to ISO/IEC 9899:1990 (``ISO C90'').
BSD October 11, 2001 BSD
Mac OS X 10.12.3 - Generated Sun Feb 5 16:40:31 CST 2017