blob: c6f68495a33d124cec901251812150c52e2d0ea3 [file] [log] [blame]
/* Simple implementation of strstr for systems without it.
This function is in the public domain. */
@deftypefn Supplemental char* strstr (const char *@var{string}, const char *@var{sub})
This function searches for the substring @var{sub} in the string
@var{string}, not including the terminating null characters. A pointer
to the first occurrence of @var{sub} is returned, or @code{NULL} if the
substring is absent. If @var{sub} points to a string with zero
length, the function returns @var{string}.
@end deftypefn
#include <stddef.h>
extern int memcmp (const void *, const void *, size_t);
extern size_t strlen (const char *);
char *
strstr (const char *s1, const char *s2)
const size_t len = strlen (s2);
while (*s1)
if (!memcmp (s1, s2, len))
return (char *)s1;
return (0);