Question

Create a program that copies the data from one file to another while converting all lowercase vowels to uppercase vowels. Your program should accept two arguments: an input file to read from and an output file to copy to. • Your program should check to make sure the output file does not already exist. If it does, print "DESTINATION FILE EXISTS." to stdout. • Print the number of characters changed to stdout using the format string "%d characters changed." • Save your code as prob1.c.

Example Run

$ ./a.out input.txt output.txt

128 characters changed.

Answer 1

Complete code in C:-

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <unistd.h>

// Checking if 'c' is a vowel or not.
int isVowel(char c) {
   c = toupper(c);
   if(c == 'A' || c == 'E' || c == 'I' || c == 'O' || c == 'U') {
       return 1;
   }
   return 0;
}

int main(int argc, char const *argv[]) {
   // Checking if all required command line arguments are present.
   if(argc < 3) {
       printf("Missing at least on of the file name...\n");
       exit(0);
   }
   // Checking if output file already exists or not?
   if(access(argv[2], F_OK) != -1) {
       printf("DESTINATION FILE ALREADY EXISTS...\n");
       exit(0);
   }
   // Opening input file in read mode.
   FILE *infp = fopen(argv[1], "r");
   // Opening output file in wirte mode.
   FILE *opfp = fopen(argv[2], "w");
   // Initialize 'changed' variable as 0
   // It will count total number of characters which will be changed.
   int changed = 0;
   // Readin input file until END OF FILE.
   while(!feof(infp)) {
       // Reading one character at a time.
       char c = fgetc(infp);
       // Checking if it is an alphabate.
       if((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
           // Checking if it is a vowel.
           if(isVowel(c)) {
               // Checking if character is already an upper case character.
               char upperC = toupper(c);
               if(upperC != c) {
                   changed += 1;
                   c = upperC;
               }
           }
       }
       // Writting character in output file.
       fputc(c, opfp);
   }
   printf("WRITTEN SUCCESSFULLY!\n%d Characters changed\n", changed);
   return 0;
}

Content of "input.txt":-

Hi! My name is Abhishek gangwar.
I'm a software engineer.

Content of "output.txt":-

HI! My nAmE Is AbhIshEk gAngwAr.
I'm A sOftwArE EngInEEr.

Screenshot of output:-