1.9_longest_line.c

// Program to print the longest line 

#include <stdio.h>

#define MAXLINE 1000    // maximum input line size

int max;                // maximum length seen so far
char line[MAXLINE];     // current input line 
char longest[MAXLINE];  // longest line saved here

int my_getline (void);
void copy (void);

int main ()
{
    int len;
    extern int max;
    extern char longest[];

    max = 0;
    while ((len = my_getline()) > 0){
        //printf("%d\n", len);
        if (len > max) 
        {
            max = len;
            copy();
        }
    }
    if (max > 0) /* there was a line */
        printf("The longest line was: %s", longest);
    return 0;
}

int my_getline(void)
{
    int c, i;
    extern char line[];

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

void copy(void)
{
    int i;
    extern char line[], longest[];
    
    i = 0;
    while (line[i] != '\0'){
        longest[i] = line[i];
        ++i;
    }
}