int res = 0;
int nval = -1;

errno = 0;
nval = nice(nval);

#ifdef 1
if ((-1 == nval) && (errno != 0))
{
    fprintf(stderr, "failed to set nice %d: %s", nval, strerror(errno));
}
#else
if (errno != 0)
{
    fprintf(stderr, "failed to set nice %d: %s", nval, strerror(errno));
}
#endif