(PHP 5, PHP 7)
stream_copy_to_stream — Copies data from one stream to another
$source
   , resource $dest
   [, int $maxlength = -1
   [, int $offset = 0
  ]] ) : int
   Makes a copy of up to maxlength bytes
   of data from the current position (or from the
   offset position, if specified) in
   source to dest. If
   maxlength is not specified, all remaining content in
   source will be copied.
  
sourceThe source stream
destThe destination stream
maxlengthMaximum bytes to copy
offsetThe offset where to start to copy data
   Returns the total count of bytes copied,  or FALSE on failure.
  
| Version | Description | 
|---|---|
| 5.1.0 | Added the offsetparameter | 
Example #1 A stream_copy_to_stream() example
<?php
$src = fopen('http://www.example.com', 'r');
$dest1 = fopen('first1k.txt', 'w');
$dest2 = fopen('remainder.txt', 'w');
echo stream_copy_to_stream($src, $dest1, 1024) . " bytes copied to first1k.txt\n";
echo stream_copy_to_stream($src, $dest2) . " bytes copied to remainder.txt\n";
?>