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STRSTR(3) FreeBSD 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);
#include <string.h>
#include <xlocale.h>
char *
strcasestr_l(const char *big, const char *little, locale_t loc);
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 strcasestr_l() function does the same as strcasestr() but takes an
explicit locale rather than using the current locale.
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 `\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:
SEE ALSO
memchr(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").
HISTORY
The strnstr() function was introduced by FreeBSD 4.5 and is non-standard.
FreeBSD 14.0-RELEASE-p6 October 11, 2001 FreeBSD 14.0-RELEASE-p6