ref: 30bf1c45cac396a3b9637cfe40cb1bba4ebca7a9
dir: /sys/src/libc/port/strstr.c/
#include <u.h> #include <libc.h> /* * Return pointer to first occurrence of s2 in s1, * 0 if none */ char* strstr(char *s1, char *s2) { char *p, *pa, *pb; int c0, c; c0 = *s2; if(c0 == 0) return s1; s2++; for(p=strchr(s1, c0); p; p=strchr(p+1, c0)) { pa = p; for(pb=s2;; pb++) { c = *pb; if(c == 0) return p; if(c != *++pa) break; } } return 0; }