#include <iostream>
#include <stdio.h>     // for perror
#include <sys/stat.h>  // for open
#include <fcntl.h>     // for open
#include <unistd.h>    // for read/write

const int BUF_SIZE = 1024;

using namespace std;

int main(int argc, char * argv[]) {

    int inFD, outFD;
    int outFlags = O_CREAT| O_WRONLY | O_TRUNC;
    int perms = S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH;
    int readSize, writeSize;

    char word[BUF_SIZE];
    string tmp;

    if (argc != 3) {
        cerr << " Usage: " << argv[0] << " inputfile outputfile" << endl;
    }

    inFD = open(argv[1], O_RDONLY) ;
    if (inFD <0) {
        tmp = argv[1];

	tmp = "Failed to open "  + tmp + " for input :";
        perror(tmp.c_str());
	exit(1);
    }

    outFD = open(argv[2],  outFlags, perms);
    if (outFD < 0) {
        tmp = argv[2];
	tmp = "Failed to open "  + tmp + " for output :";
	perror(tmp.c_str());
	exit(1);
    }

    while((readSize = read(inFD, word, BUF_SIZE)) > 0) {
       writeSize = write(outFD, word, readSize);
       if ( readSize != writeSize) {
           perror("Write Failed :");
	   exit(0);
       }
    }

    close(inFD);
    close(outFD);
    
    return 0;
}