ref: a004412434813b0500807d46d09c2d0cef13205d
dir: /src/libc/string/strstr.c/
#include <stddef.h> #include <string.h> #undef strstr char * strstr(const char *s1, const char *s2) { const char *p; int c = *s2; int len; if ((len = strlen(s2)) == 0) return s1; for (p = s1; p = strchr(p, c); ++p) { if (!strncmp(p, s2, len)) return p; } return NULL; }