title: file_put_contents and file_get_contents exhaust memory size
body: <p>I have some simple trying to write from one file to another.</p>
  
  <pre><code>$content=file_get_contents("C:\Users\Borut\Desktop\sql_PW1\mm_ads (1).sql");
  file_put_contents("C:\Users\Borut\Desktop\sql_PW1\New", $content);
  </code></pre>
  
  <p>The file which I read is about 80M big, the memory limit in php is 128M, but I get an error:</p>
  
  <pre><code>Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 80739522 bytes)
  </code></pre>
  
  <p>So the memory is exhausted even though the memory I am trying to allocate is actually smaller?? I can make this work by increasing the memory limit, but I want to know why it doesnt work with this limit.</p>