ref: 5b81e7de3f1ab3691438878cf1da912a54138d5f
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);
}