Reverse file content : fstream « File « C++






  1. C++
  2. File
  3. fstream

Reverse file content

 
#include <iostream>
#include <fstream>
#include <cstdlib>
using namespace std;

int main(int argc, char *argv[])
{
  if(argc!=3) {
    cout << "Usage: Reverse <filename> <num>\n";
    return 1;
  }

  fstream inout(argv[1], ios::in | ios::out | ios::binary);

  if(!inout) {
    cout << "Cannot open input file.\n";
    return 1;
  }

  long e, i, j;
  char c1, c2;
  e = atol(argv[2]);

  for(i = 0, j = e; i < j; i++, j--) {
    inout.seekg(i, ios::beg);
    inout.get(c1);
    inout.seekg(j, ios::beg);
    inout.get(c2);

    inout.seekp(i, ios::beg);
    inout.put(c2);
    inout.seekp(j, ios::beg);
    inout.put(c1);
  }

  inout.close();
  return 0;
}








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