Calculating File, Directory, and Disk Sizes - PHP

Calculating file, directory, and disk sizes is a common task in all sorts of applications. This section introduces a number of standard PHP functions suited to this task.

filesize()

int filesize (string filename)

The filesize() function returns the size, in bytes, of filename. An example follows:

<?php
$file = "/www/htdocs/book/chapter1.pdf";
$bytes = filesize("$file"); // Returns 91815
echo "File ".basename($file)." is $bytes bytes, or
".round($bytes / 1024, 2)." kilobytes.";
?>

This returns the following:

--------------------------------------------File 852Chapter16R.rtf is 91815 bytes, or 89.66 kilobytes
--------------------------------------------

disk_free_space()

float disk_free_space (string directory)

The disk_free_space() function returns the available space, in bytes, allocated to the disk partition housing the directory specified by directory. An example follows:

<?php
$drive = "/usr";
echo round((disk_free_space($drive) / 1048576), 2);
?>

This returns:

--------------------------------------------2141.29
--------------------------------------------

Note that the returned number is in megabytes (MB), because the value returned from disk_free_space() was divided by 1,048,576, which is equivalent to 1MB.

disk_total_space()

float disk_total_space (string directory)

The disk_total_space() function returns the total size, in bytes, consumed by the disk partition housing the directory specified by directory. If you use this function in conjunction with disk_free_space(), it's easy to offer useful space allocation statistics:

<?php
$systempartitions = array("/", "/home","/usr", "/www");
foreach ($systempartitions as $partition) {
$totalSpace = disk_total_space($partition) / 1048576;
$usedSpace = $totalSpace - disk_free_space($partition) / 1048576;
echo "Partition: $partition (Allocated: $totalSpace MB.
Used: $usedSpace MB.)";
}
?>

This returns:

--------------------------------------------Partition: / (Allocated: 3099.292 MB. Used: 343.652 MB.)
Partition: /home (Allocated: 5510.664 MB. Used: 344.448 MB.)
Partition: /usr (Allocated: 4127.108 MB. Used: 1985.716 MB.) Partition: /usr/local/apache2/htdocs (Allocated: 4127.108 MB. Used: 1985.716 MB.)
--------------------------------------------

Please check back for the next part of the series.