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

The strcasestr() function is similar to strstr(), but ignores the case of both strings. The strnstr() function locates the first occurrence of the NUL-terminated string little in the string big, where not more than len characters are searched. Characters that appear after a ‘\0’ character are not searched. Since the strnstr() function is a NetBSD specific 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 occurs 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);

SEE ALSO

index(3), memchr(3), rindex(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 C90”).

HISTORY

The strnstr() function originated in FreeBSD.