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 *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 ignores the case of
both strings.
The strnstr() function locates the first occurrence of the null-termi‐
nated 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 FreeBSD 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);
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 ALSOmemchr(3), memmem(3), strchr(3), strcspn(3), strpbrk(3), strrchr(3),
strsep(3), strspn(3), strtok(3), wcsstr(3)STANDARDS
The strstr() function conforms to ISO/IEC 9899:1990 (“ISO C90”).
BSD October 11, 2001 BSD