how do i modify the way in which readdir() lists files.

I have a script that creates a zip package daily in a directory. After this is done another script deletes the 'last' file in the directory so I always have just the latest x days.

whil开发者_Python百科e (false !== ($file = readdir($handle))) 
    {
            if ($file != "." && $file != "..")
            {
                echo "$file";
                echo '<br>';

                //count files
                $file_count = $file_count + 1;
            }
        }

However suddenly readdir() is returning the list of files like this:

March_16_2011.zip

March_12_2011.zip

March_13_2011.zip

March_14_2011.zip

March_15_2011.zip

So of course rather than the oldest file being removed the newest one is.

When I look at the files in FTP they are all dated correctly.

Why is readdir() returning them out of order in this case? How do I force it to order them in a way I want? (By date)

readdir returns the filenames in an arbitrary order, depending on how the OS returns the entries from the filesystem. You need to manually sort the result list:

foreach (glob("*") as $fn) {
    $files[$fn] = filemtime($fn);
}
arsort($files);
$files = array_keys($files);

AFAIK there is no PHP function to sort by date, but you can write your own:

$filearr = array();
while (false !== ($file = readdir($handle))) 
{
        if ($file != "." && $file != "..")
        {
             $stat = stat($file);
             $filearr["$file"] = $stat['mtime'];
        }
 }

asort($filearr);

Also see: http://nl2.php.net/manual/en/function.stat.php

foreach (glob("$dir/*.zip") as $f)  echo $f;

that's all code you need if give your files sensible names, like 2011-03-12.zip.

You can not force readdir() to order the files. But you can check which is the oldest file with stat().

Try using scandir instead of readdir to set a sorting for your files

More info on scandir: http://uk3.php.net/manual/en/function.scandir.php

Otherwise you could read your folderstructur into an array and sort it afterwards using the various php sorting functions.

I would use glob(). That sorts them automatically, via number as well, and might be better to get the files, too...

glob("data/*.{zip,tar.gz,tar.bz2}", GLOB_BRACE);

But to sort via the date, you may have to do something like this:

$data = $FILE_NAME_VAR_HERE; // duh
$parts = explode("_"); // explode it by underscore   
unset($parts[0]); // unset the first one 
$data = implode("_", $parts); // return the string without it

Untested.

Hope this fixes your problem :)

Ol' faithful array_multisort() could also be drafted in to work with the list of files from glob().

$files = glob("*.zip");
$times = array_map('filemtime', $files);
array_multisort($times, $files);