(PHP 4, PHP 5)
ftruncate — Truncates a file to a given length
$handle
   , int $size
   )
   Takes the filepointer, handle, and truncates the file to
   length, size.
  
handle
     The file pointer.
Note:
The
handlemust be open for writing.
size
     The size to truncate to.
Note:
If
sizeis larger than the file then the file is extended with null bytes.If
sizeis smaller than the file then the file is truncated to that size.
   Returns TRUE on success or FALSE on failure.
  
| Version | Description | 
|---|---|
| 4.3.3 | 
        Prior to this release  ftruncate() returned an
        integer value of 1 on success, instead of
        boolean TRUE.
        | 
      
Example #1 File truncation example
<?php
$filename = 'lorem_ipsum.txt';
$handle = fopen($filename, 'r+');
ftruncate($handle, rand(1, filesize($filename)));
rewind($handle);
echo fread($handle, filesize($filename));
fclose($handle);
?>
Note:
The file pointer is not changed.