Question

1. Write a program that prompts the user for a filename, then reads that file in and displays the contents backwards, line by line, and character-by character on each line. You can do this with scalars, but an array is much easier to work with. If the original file is:

abcdef
ghijkl

the output will be:

lkjihg
fedcba

Need Help with this be done in only PERL. Please use "reverse"

Answer 1

#include <stdio.h>

#include <string.h>

#define MAX 100

// Function to reverse the file content

void reverseContent(char* x)

{

    // Opening the path entered by user

    FILE* fp = fopen(x, "a+");

    // If file is not found then return

    if (fp == NULL) {

        printf("Unable to open file\n");

        return;

    }

  

    // To store the content

    char buf[100];

    int a[MAX], s = 0, c = 0, l;

    // Explicitly inserting a newline

    // at the end, so that o/p doesn't

    // get effected.

    fprintf(fp, " \n");

    rewind(fp);

    // Adding current length so far +

    // previous length of a line in

    // array such that we have starting

    // indices of upcoming lines

    while (!feof(fp)) {

        fgets(buf, sizeof(buf), fp);

        l = strlen(buf);

        a = s += l;

    }

    // Move the pointer back to 0th index

    rewind(fp);

    c -= 1;

// Print the contents

    while (c >= 0) {

        fseek(fp, a, 0);

        fgets(buf, sizeof(buf), fp);

        printf("%s", buf);

        c--;

    }

    return ;

}

// Driver Code

int main()

{

    // File name in the directory

    char x[] = "file1.txt";

    // Function Call to reverse the

    // File Content

    reverseContent(x);

    return 0;

}