ref: e6fa5a21f97c13caea47c0a434d5672ab45da2d6
dir: /sys/src/libc/port/runestrecpy.c/
#include <u.h> #include <libc.h> Rune* runestrecpy(Rune *s1, Rune *es1, Rune *s2) { if(s1 >= es1) return s1; while(*s1++ = *s2++){ if(s1 == es1){ s1[-1] = '\0'; break; } } return s1-1; }