mirror of
https://github.com/autc04/Retro68.git
synced 2024-11-17 19:06:36 +00:00
42 lines
1.0 KiB
C
42 lines
1.0 KiB
C
|
/* 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
|
||
|
|
|
||
|
|
|
||
|
|
*/
|
||
|
|
|
||
|
|
|
||
|
|
/* FIXME: The above description is ANSI compiliant. This routine has not
|
||
|
|
been validated to comply with it. -fnf */
|
||
|
|
|
||
|
|
#include <stddef.h>
|
||
|
|
|
||
|
|
extern char *strchr (const char *, int);
|
||
|
|
extern int strncmp (const void *, const void *, size_t);
|
||
|
|
extern size_t strlen (const char *);
|
||
|
|
|
||
|
|
char *
|
||
|
|
strstr (const char *s1, const char *s2)
|
||
|
|
{
|
||
|
|
const char *p = s1;
|
||
|
|
const size_t len = strlen (s2);
|
||
|
|
|
||
|
|
for (; (p = strchr (p, *s2)) != 0; p++)
|
||
|
|
{
|
||
|
|
if (strncmp (p, s2, len) == 0)
|
||
|
|
return (char *)p;
|
||
|
|
}
|
||
|
|
return (0);
|
||
|
|
}
|