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 *big, const char *little);
char *
strcasestr(const char *big, const char *little);
char *
strnstr(const char *big, const char *little, size_t len);

DESCRIPTION

The strstr() function locates the first occurrence of the

null-terminated
string little in the null-terminated string big.

The strcasestr() function is similar to strstr(), but ig

nores the case of
both strings.

The strnstr() function locates the first occurrence of the

null-terminated string little in the string big, where not more than

len characters
are searched. Characters that appear after a ` ' character

are not
searched. Since the strnstr() function is a FreeBSD specif

ic API, it
should only be used when portability is not a concern.

RETURN VALUES

If little is an empty string, big is returned; if little oc

curs nowhere
in big, NULL is returned; otherwise a pointer to the first

character of
the first occurrence of little 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)

STANDARDS

The strstr() function conforms to ISO/IEC 9899:1990 (``ISO

C89'').

BSD October 11, 2001

BSD