ref: 0e54aa2a4df49f9a4fb7f1a275940332d3bee3c6
dir: /sys/src/libc/port/utfecpy.c/
#include <u.h> #include <libc.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; }