ref: 3c2cec93a9475a27f854ac2541f69c4a7a0b3657
dir: /lib/c/strstr.c/
#include <stddef.h> #include <string.h> #undef strstr char * strstr(const char *s1, const char *s2) { const char *p; int c = *s2; if (c == '\0') return NULL; for (p = s1; p = strchr(p, c); ++p) { if (!strcmp(p, s2)) return (char *) p; } return NULL; }