C - The C Answer (2nd Edition) - Exercise 1-16

/* Revise the main routine of the longest-line program so it will correctly print the
   length of arbitrarily long input lines, and as much as possible of the text. */

#include <stdio.h>
#define MAXLINE 1000        /* maximum input line size */

int getline(char line[], int maxline);
void copy(char to[], char from[]);

/* print longest input line */
main()
{
	int len;                /* current line length */
	int max;                /* maximum length seen so far */
	char line[MAXLINE];     /* current input line */
	char longest[MAXLINE];  /* longest line saved here */

	max = 0;
	while((len = getline(line, MAXLINE)) > 0)
	{
		printf("%d, %s", len, line);
		if(len > max)
		{
			max = len;
			copy(longest, line);
		}
	}
	if(max > 0)             /* there was a line */
	{
		printf("%s", longest);
	}
	return 0;
}

/* getline: read a line into s, return length */
int getline(char s[], int lim)
{
	int c, i, j;
	j = 0;
	for(i = 0; (c = getchar()) != EOF && c != '\n'; ++i)
	{
		if(i < lim - 2)
		{
			s[j] = c;       /* line still in boundaries */
			++j;
		}
	}
	if(c == '\n')
	{
		s[j] = c;
		++j;
		++i;
	}
	s[j] = '\0';
	return i;
}

/* copy: copy 'from' into 'to'; assume to is big enough */
void copy(char to[], char from[])
{
	int i;
	i = 0;
	while((to[i] = from[i]) != '\0')
	{
		++i;
	}
}