ref: 47c48b42c3463844a3fa0ca0a9d6dbc8a2e8b0f6 dir: /sys/src/ape/lib/ap/gen/strcat.c/
#include <string.h> char* strcat(char *s1, const char *s2) { strcpy(strchr(s1, 0), s2); return s1; }