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PHP filesize() On Files > 2 GB

I have been struggeling on how to get the valid filesize of a file that is >= 2 GB in PHP.

Example
Here I am checking the filesize of a file that is 3,827,394,560 bytes large with the filesize() function: 

echo "The file is " . filesize('C:\MyFile.rar') . " bytes.";

Result
This is what it returns:

The file is -467572736 bytes.

Background
PHP uses signed integers, which means that the maximum number it can represent is 2,147,483,647 (+/- 2 GB).
This is where it is limited.

Solution

  • http://us.php.net/manual/en/function.filesize.php#102135 gives a complete and correct means for finding the size of a file larger than 2GB in PHP, without relying on OS-specific interfaces.

    The gist of it is that you first use filesize to get the "low" bits, then open+seek the file to determine how many multiples of 2GB it contains (the "high" bits).