Example1-20.c

#include<stdio.h>

#define TABINC 8

main()
{

	int c, nb, pos;
	
	nb = 0;
	pos = 1;
	while ((c = getchar()) != EOF) {
		if ( c == '\t') {
			nb = TABINC - (pos - 1) % TABINC;
			while (nb > 0) {
				putchar(' ');
				++pos;
				--nb;
			}
		} else if (c == '\n') {
			putchar(c);
			pos = 1;
		} else {
			putchar(c);
			++pos;
		}
	}
}