Miscellany

while  (tav != '\n') {
	scanf("%c", & tav);
	if(tav=='\n')
		   break;
        if (IS_DIGIT(tav)) {
            str = "digit";
        } else if (IS_UPPER(tav)) {
            str = "upper";
        } else if (IS_LOWER(tav)) {
            str = "lower";
        } else {
            str = "misc";
        }
	printf("%c %10d %10.2f %10d %+10d %10s\n", tav, tav, sqrt(tav), tav*tav, tav - prev_tav, str);
	prev_tav = tav;
}