K&R2 Exercise 1-22

1-22.c

/*K&R2 Exercise 1-22 "fold"*/
#include <stdio.h>

#define MAXLINE 1024
#define FOLD 80

int getline(char[], int);
int mod(int, int);

int main()
{
	int c, i, l;
	char line[MAXLINE];
	l = 0;
	while((c = getline(line, MAXLINE)) != 0){
		for(i = 0; i < c; ++i){
			++l;
			if(l == FOLD){
				while(line[i] != ' ')
					i--;
				line[i] = '\n';
				l = 0;
			}
		}
		printf("%s", line);
	}

}

int getline(char s[], int lim)
{
	int c, i;

	for(i = 0; i < lim-1 && (c = getchar()) != EOF && c !='\n'; ++i)
		s[i] = c;
	if(c == '\n') {
		s[i] = c;
		++i;
	}
	s[i] = '\0';
	return i;
}

int mod(int dividend, int divisor)
{
	return dividend - (dividend/divisor * divisor);
}