Exercise 1.16 - Print length of arbitrary long input line¶
Question¶
Revise the main routine of the longest-line program so it will correctly print the length of arbitrary long input lines, and as much as possible of the text.
Solution¶
/**
* Exercise 1.16
*
* Write a program to print the length of an arbitrarily long input line
* and as much text as possible
*
**/
#include <stdio.h>
/* The size of the output that we would like */
#define MAX 1000
/* define our functions*/
int get_line(char arr[], int lim);
void copy(char to[], const char from[]);
int main() {
int len, max;
char line[MAX];
char longest[MAX];
max = 0;
while ((len = get_line(line, MAX)) > 0) {
if (len > max) {
max = len;
copy(longest, line);
}
}
if (max > 0) {
printf("length = %i, string=%s", max, longest);
}
return 0;
}
/* get a line in a character array */
int get_line(char arr[], int lim) {
int c, i;
for (i = 0; i < lim - 1 && (c = getchar()) != EOF && c != '\n'; ++i) {
arr[i] = c;
}
if (c == '\n') {
arr[i] = c;
++i;
} else {
/* Continue to count the length even if it is longer than the max */
while ((c = getchar() != EOF) && c != '\n') {
++i;
}
if (c == '\n') {
arr[i] = c;
++i;
}
}
arr[i] = '\0';
return i;
}
/* copy one character array to another */
void copy(char to[], const char from[]) {
int i;
i = 0;
while ((to[i] = from[i]) != '\0') {
++i;
}
}
Explanation¶
A string in C is a character array which ends in 0. getline is a function in our program, which reads one character at a time using getchar and stores it in a character array called s[] and it returns the length of the array.
We keep track of each line and it’s length using a variable, max. If the length of the line is greater than max, then we copy that line into the maxline using a copy routine.
At the end of the program, whichever was the longest line that was copied in maxline array, we just print that.