compare-files.cc

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

#define null (0)

int main(int argc, char** argv)
{
   if (argc != 3)
   {
      printf("Usage: compare-files.exe FILENAME1 FILENAME2\n");
      exit(EXIT_FAILURE);
   }

const char* FILENAME1 = argv[1];
   const char* FILENAME2 = argv[2];

bool error1 = false;
   bool error2 = false;

FILE* f1 = fopen(FILENAME1, "rb");
   if (f1 == null)
   {
      error1 = true;
   }

FILE* f2 = fopen(FILENAME2, "rb");
   if (f2 == null)
   {
      error2 = true;
   }

if (error1 && error2)
   {
      printf("RESULT=NO Error opening files \"%s\" and \"%s\" for reading\n", FILENAME1, FILENAME2);
      exit(EXIT_FAILURE);
   }
   if (error1)
   {
      printf("RESULT=NO Error opening file \"%s\" for reading\n", FILENAME1);
      exit(EXIT_FAILURE);
   }
   if (error2)
   {
      printf("RESULT=NO Error opening file \"%s\" for reading\n", FILENAME2);
      exit(EXIT_FAILURE);
   }

   //std::cout << "EOF=" << EOF << '\n';

   int count = 0;
   for (;;)
   {
      int ch1 = fgetc(f1);
      int ch2 = fgetc(f2);
      count++;
      if ((ch1 == EOF) && (ch2 == EOF))
      {
         printf("RESULT=YES\n");
         exit(EXIT_SUCCESS);
      }
      else if ((ch1 == EOF) || (ch2 == EOF))
      {
         printf("RESULT=NO Files are of different lengths at position %d\n", count);
         exit(EXIT_FAILURE);
      }
      else if (ch1 != ch2)
      {
         printf("RESULT=NO Files different at position %d\n", count);
         exit(EXIT_FAILURE);
      }
   }
}