File input/output is part of Short Circuit's Console Program Basics selection.
Task

Create a file called   "output.txt",   and place in it the contents of the file   "input.txt",   via an intermediate variable.

In other words, your program will demonstrate:

   how to read from a file into a variable
   how to write a variable's contents into a file


Oneliners that skip the intermediate variable are of secondary interest — operating systems have copy commands for that.




<?php
 
if (!$in = fopen('input.txt', 'r')) {
    die('Could not open input file.');
}
 
if (!$out = fopen('output.txt', 'w')) {
    die('Could not open output file.');
}
 
while (!feof($in)) {
    $data = fread($in, 512);
    fwrite($out, $data);
}
 
fclose($out);
fclose($in);
?>