Ruby: missing/strstr.c Source File

Ruby 4.0.5p0 (2026-05-20 revision 64336ffd0ee9e1f4c05891695a3d7b49cb709721)

strstr.c
1/* public domain rewrite of strstr(3) */
2
3#include "ruby/missing.h"
4
5size_t strlen(const char*);
6
7char *
8strstr(const char *haystack, const char *needle)
9{
10 const char *hend;
11 const char *a, *b;
12
13 if (*needle == 0) return (char *)haystack;
14 hend = haystack + strlen(haystack) - strlen(needle) + 1;
15 while (haystack < hend) {
16 if (*haystack == *needle) {
17 a = haystack;
18 b = needle;
19 for (;;) {
20 if (*b == 0) return (char *)haystack;
21 if (*a++ != *b++) {
22 break;
23 }
24 }
25 }
26 haystack++;
27 }
28 return 0;
29}