ref: 74bcc2aa4c0b8e2d9915ae2cda6e4b2fabf56e95 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; }