c_exercises/1-16.c

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

/* ggetline: read a line into 'line', return length */
int ggetline(char line[], int maxline){
  int c, i;
  for (i=0; (c=getchar()) != EOF && c!='\n'; ++i){
    if (i<maxline-1){
      line[i]=c;
    }
    else if (i==maxline-2){
      line[i]='\n';
      line[i++]='\0';
    }
  }
  return i;
}

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

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