Redirect standard output and error

#include <iostream>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
 
/**
 * @brief main The program entry point
 * @return Returns exit code
 */
int main()
{
    // copy the file descriptor 1 (standard output) to a new descriptor for the future use
    int newStdout = dup(1); 
 
    // could not duplicate the file descriptor 1
    if(newStdout == -1){
        std::cerr << "Could not duplicate stdout" << std::endl;
        exit(errno);
    }
 
    // close file descriptor of stdout
    int closed = close(1);
 
    // stdout not closed
    if(closed == -1){
        std::cerr << "Cloud not close stdout" << std::endl;
        exit(errno);
    }
 
    // open/create a new file where standard output and standard error will be redirected to 
    int file = open("output.log", O_CREAT | O_WRONLY | O_TRUNC, S_IRUSR | S_IWUSR | S_IRGRP);
 
    // something went wrong while opening the file
    if(file == -1){
        std::cerr << "Cloud not open/create a file for redirecting standard output in" << std::endl;
        exit(errno);
    }
    
    // duplicate the standard output into descriptor 2
    // this will result in descriptors 1 and 2 pointing to the same file
    int cerrDescriptor = dup2(1, 2);
 
    // make sure we can successfully duplicate the descriptor
    if(cerrDescriptor == -1){
        std::cerr << "Cloud not redirect standard error into standard output stream" << std::endl;
        exit(errno);
    }
 
    // perform cout to write into standard output and cerr to write into the standard error
    // as we redirected both 1 and 2 descriptors into the file output.log, the following text
    // will not appear on the console screen, but will be written into the file
    std::cout << "Writing some text" << std::endl;
    std::cerr << "Other error text" << std::endl;
 
    // finally print text on the console using plain write operation into the copied stdout stream 
    write(newStdout, "Hello\n", 6); 
 
    // close file
    close(file);
 
    return 0;
}

g++ redirect.cpp -o redirect