ref: 3ffbf7ced234d4e6f0809ba7e16b01842820f6d8
dir: /sys/src/libc/9sys/rerrstr.c/
#include <u.h>
#include <libc.h>
void
rerrstr(char *buf, uint nbuf)
{
char tmp[ERRMAX];
tmp[0] = 0;
errstr(tmp, sizeof tmp);
utfecpy(buf, buf+nbuf, tmp);
errstr(tmp, sizeof tmp);
}