replace tabs with the proper number of blanks

/* 1-20. Write a program detab that replaces tabs in the input
		with the proper number of blanks to space to the next 
		tab stop. Assume a fixed set of tab stops, say every n
		columns. Should n be a variable or a symbolic parameter?	*/

#include <stdio.h>

#define	TABINC	8

/*	replace tabs with the proper number of blanks	*/
void main()
{
	int c, nb, pos;

	nb = 0;				/*	number of blanks necessary		*/
	pos = 1;			/*	position of character in line	*/
	while((c = getchar()) != EOF) {
		if( c == '\t') {	/*	tab character	*/
			nb = TABINC - (pos - 1) % TABINC;
			while( nb > 0 ) {
				putchar(' ');
				++pos;
				--nb;
			}
		} else if( c == '\n') {	/*	newline character		*/
			putchar(c);
			pos = 1;
		} else {
			putchar(c);			/*	all other characters	*/
			++pos;
		}
	}
}