ref: 4a1fc5ccb596a0f88f465b81a638f0068e82f0b9
dir: /libkern/utfecpy.c/
#include "lib9.h" char* utfecpy(char *to, char *e, char *from) { char *end; if(to >= e) return to; end = memccpy(to, from, '\0', e - to); if(end == nil){ end = e; while(end>to && (*--end&0xC0)==0x80) ; *end = '\0'; }else{ end--; } return end; }