ref: c1d40df49550393f3afe53fb6e6d500dfa8eb7a8
dir: /sys/src/ape/lib/ap/gen/strstr.c/
#include <string.h> /* Return pointer to first occurrence of s2 in s1, NULL if none */ char* strstr(const char *s1, const char *s2) { char *p, *pa, *pb; int c0, c; c0 = *s2; if(c0 == 0) return (char *)s1; s2++; for(p=strchr(s1, c0); p; p=strchr(p+1, c0)) { pa = p; for(pb=(char*)s2;; pb++) { c = *pb; if(c == 0) return p; if(c != *++pa) break; } } return 0; }