ref: 99ed32c9f5a5aaf6b32ebb49ce5c7045ffe7d0b0 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; }