How to calculate entire directory size with FTP access using PHP

Question

I have a number of different hosting accounts set up for clients and need to calculate the amount of storage space being used on each account, which would update regularly.

I have a database set up to record each clients storage usage.

I attempted this first using a PHP file on each account, run by a Cron Job. If run manually by myself, it would output the correct filesize and update the correct size to the database, although when run from the Cron Job, it would output 0.

I then attempted to run this file from a Cron Job from the main account but figured this wouldn't actually work as my hosting would block files from another server and I would end up with the same result as before.

I am now playing around with FTP access to each account from a Cron Job from the main account which looks something like below, the only problem is I don't know how to calculate directory size rather than single file sizes using FTP access, and don't know how to reiterate this way? Hoping somebody might be able to help here before I end up going around in circles?

I will also add the previous first attempt too.

$ftp_conn = ftp_connect($ftp_host, 21, 420) or die("Could not connect to server");
$ftp_login = ftp_login($ftp_conn, $ftp_username, 'mypassword');

$total_size = 0;                    
$contents = ftp_nlist($ftp_conn, ".");
// output $contents
foreach($contents as $folder){

    while($search == true){

        if($folder == '..' || $folder == '.'){

        } else {
            $file = $folder; 
            $res = ftp_size($ftp_conn, $file);

            if ($res != -1) {
                $total_size = $total_size + $res;
            } else {
                $total_size = $total_size;
            }
        }
    }
}

ftp_close($ftp_conn); 

This doesn't work as it doesn't calculate folder sizes and I don't know how to open the reiterate using this method?

---

This second script did work but would only work if opened manually, and return 0 if run by the cron job.

class Directory_Calculator {

    function calculate_whole_directory($directory)
    {
        if ($handle = opendir($directory))
        {
            $size = 0;
            $folders = 0;
            $files = 0;

            while (false !== ($file = readdir($handle)))
            {
                if ($file != "." && $file != "..")
                {
                    if(is_dir($directory.$file))
                    {
                    $array = $this->calculate_whole_directory($directory.$file.'/');
                    $size += $array['size'];
                    $files += $array['files'];
                    $folders += $array['folders'];
                    }
                    else
                    {
                    $size += filesize($directory.$file);
                    $files++;
                    }
                }
            }
            closedir($handle);
        }

        $folders++;

        return array('size' => $size, 'files' => $files, 'folders' => $folders);
    }

}

/* Path to Directory - IMPORTANT: with '/' at the end */
$directory = '../public_html/'; 

// return an array with: size, total files & folders
$array = $directory_size->size($directory); 

$size_of_site = $array['size'];

echo $size_of_site;

Please bare in mind that I am currently testing and none of the MySQLi or PHP scripts are secure yet.

Answer 1

If your server supports MLSD command and you have PHP 7.2 or newer, you can use ftp_mlsd function:

function calculate_whole_directory($ftp_conn, $directory)
{
    $files = ftp_mlsd($ftp_conn, $directory) or die("Cannot list $directory");
    $result = 0;
    foreach ($files as $file)
    { 
        if (($file["type"] == "cdir") || ($file["type"] == "pdir"))
        {
            $size = 0;
        }
        else if ($file["type"] == "dir")
        {
            $size = calculate_whole_directory($ftp_conn, $directory."/".$file["name"]);
        }
        else
        {
            $size = intval($file["size"]);
        }
        $result += $size;
    } 

    return $result; 
} 

If you do not have PHP 7.2, you can try to implement the MLSD command on your own. For a start, see user comment of the ftp_rawlist command:
https://www.php.net/manual/en/function.ftp-rawlist.php#101071

---

If you cannot use MLSD, you will particularly have problems telling if an entry is a file or folder. While you can use the ftp_size trick, as you do, calling ftp_size for each entry can take ages.

But if you need to work against one specific FTP server only, you can use ftp_rawlist to retrieve a file listing in a platform-specific format and parse that.

The following code assumes a common *nix format.

function calculate_whole_directory($ftp_conn, $directory)
{
    $lines = ftp_rawlist($ftp_conn, $directory) or die("Cannot list $directory");
    $result = 0;
    foreach ($lines as $line)
    { 
        $tokens = preg_split("/\s+/", $line, 9); 
        $name = $tokens[8];
        if ($tokens[0][0] === 'd')
        {
            $size = calculate_whole_directory($ftp_conn, "$directory/$name");
        }
        else
        {
            $size = intval($tokens[4]);
        }
        $result += $size;
    } 

    return $result; 
} 

---

Based on PHP FTP recursive directory listing.

---

Regarding cron: I'd guess that the cron does not start your script with a correct working directory, so you calculate a size of a non-existing directory.

Use an absolute path here:

$directory = '../public_html/'; 

Though you better add some error checking so that you can see yourself what goes wrong.