Commit | Line | Data |
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252b5132 RH |
1 | /* Simple implementation of strstr for systems without it. |
2 | This function is in the public domain. */ | |
3 | ||
4 | /* | |
5 | ||
39423523 | 6 | @deftypefn Supplemental char* strstr (const char *@var{string}, const char *@var{sub}) |
252b5132 | 7 | |
39423523 | 8 | This function searches for the substring @var{sub} in the string |
fa9f0e33 | 9 | @var{string}, not including the terminating null characters. A pointer |
99b58139 | 10 | to the first occurrence of @var{sub} is returned, or @code{NULL} if the |
39423523 DD |
11 | substring is absent. If @var{sub} points to a string with zero |
12 | length, the function returns @var{string}. | |
252b5132 | 13 | |
39423523 | 14 | @end deftypefn |
252b5132 | 15 | |
252b5132 RH |
16 | |
17 | */ | |
18 | ||
19 | ||
20 | /* FIXME: The above description is ANSI compiliant. This routine has not | |
21 | been validated to comply with it. -fnf */ | |
22 | ||
23 | char * | |
24 | strstr (s1, s2) | |
25 | char *s1, *s2; | |
26 | { | |
27 | register char *p = s1; | |
28 | extern char *strchr (); | |
29 | extern int strncmp (); | |
30 | #if __GNUC__==2 | |
31 | extern __SIZE_TYPE__ strlen (); | |
32 | #endif | |
33 | register int len = strlen (s2); | |
34 | ||
35 | for (; (p = strchr (p, *s2)) != 0; p++) | |
36 | { | |
37 | if (strncmp (p, s2, len) == 0) | |
38 | { | |
39 | return (p); | |
40 | } | |
41 | } | |
42 | return (0); | |
43 | } |