NAME
strstr
,
strcasestr
, strnstr
—
locate a substring in a
string
LIBRARY
library “libc”
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
Thestrstr
()
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:
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)
STANDARDS
The strstr
() function conforms to
ISO/IEC 9899:1990
(“ISO C90”).