Copy file content to another file - PHP

Copyfile.php

<?php
  echo copy("source.txt","target.txt");
  //Another way

  //Get all the content from the file
  $fileContents = file_get_contents('1.txt');
  //Output to new file
  $fh = fopen('output.txt', 'w+');
  file_put_contents($fh, $fileContents);
  fclose($fh);
?>