/*
 * dupTOstdout1.c++ dup() an open file to the slot of stdout
 * $ ./a.out dupOut
 */
#include <iostream>
using namespace std;
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

int main(int ac, char *av[]){
    int fd1;   // dupTOstdout1.c++
               // $ ./a.out dupOut
    if(ac < 2){
      cerr << "File name not specified\n";
      exit(1);
    }

    fd1 = open(av[1], O_CREAT | O_WRONLY, 0666);
    if(fd1 == -1){
      cerr << "File open error\n";
      exit(1);
    }    
    cout << "Line before close(fileno(stdout))\n";
    close(fileno(stdout));
    cout << "Line after close(fileno(stdout))\n";
    dup(fd1); 
    cout << "Line after dup(fd1)\n";

    close(fd1);
    return 0;
}