blob: 60902ea40ee80b513a525f9403728398ea876d7e (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
|
/* 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);
}
|
