error.c:29
static int
err_position(buf, len)
    char *buf;
    long len;
{
    ruby_set_current_source();
    if (!ruby_sourcefile) {
	return 0;
    }
    else if (ruby_sourceline == 0) {
	return snprintf(buf, len, "%s: ", ruby_sourcefile);
    }
    else {
	return snprintf(buf, len, "%s:%d: ", ruby_sourcefile, ruby_sourceline);
    }
}
