CODEWITHSUNDEEP
phpsortingiteratorfilesystems
Elfy
Elfy

Reputation: 1863

Order in FilesystemIterator

http://php.net/manual/en/class.filesystemiterator.php

I noticed that FilesystemIterator returns the files ordered by name. Can anyone confirm this is true and it always happens? I haven't found anything in the docs.

Another question, is there any way to get the files ordered by the creation time on the disk? getCTime() seems to return the change time so I can't use it with usort()

Upvotes: 4

Views: 3232

Answers (4)

William
William

Reputation: 305

In fact, the order can be random. So, you have to sort arbitrarily. To sort alphabetically, use this simple construction:

$files = iterator_to_array(new RecursiveDirectoryIterator('.', FilesystemIterator::SKIP_DOTS | FilesystemIterator::UNIX_PATHS), true);
ksort($files);

Set flags as needed.

Upvotes: 4

alfallouji
alfallouji

Reputation: 1170

I did some digging into PHP internals.

If I am not mistaken, the __construct method of FileSystemIterator ends up using the VCWD_OPENDIR C macro : https://github.com/php/php-src/blob/2f443acad19816e29b0c944426238d9f23af1ae2/main/streams/plain_wrapper.c#L908

This is a macro to the C Function opendir().

By looking at the documentation of that function, I can't see anything that would allow to define any kind of order : http://pubs.opengroup.org/onlinepubs/009695399/functions/opendir.html

Knowing that, I would assume that the order is not enforced and could vary depending on the type of filesystem used (fat32, ntfs, etc.).

Therefore, If I were you - to be safe - I would implement a PHP function that would order them the way I want.

For your 2nd question, check : PHP: how can I get file creation date?

Upvotes: 4

Rizier123
Rizier123

Reputation: 59701

I noticed that FilesystemIterator returns the files ordered by name. Can anyone confirm this is true and it always happens? I haven't found anything in the docs.

You can't sort data which comes from an Iterator. Why? Because an Iterator is lazy with the data handling, that means the iterator only knows about 1 item at the time.

So the Iterator doesn't sort the files in any way and you can't sort the data directly from an iterator, you would have to save it into an array or so to be able to sort the data.

Another question, is there any way to get the files ordered by the creation time on the disk?

usort() is a good idea, but not with DirectoryIterator::getCTime(), because this is a method of the iterator. But you can use: filemtime() (Just be aware of that the function is cached!)

Upvotes: 1

sleepless_in_seattle
sleepless_in_seattle

Reputation: 2224

You have to sort them outside of the FilesystemIterator as it only iterates.

Here's an example:

$files = array();
$dir = new DirectoryIterator('.');
foreach ($dir as $fileinfo) {     
   $files[$fileinfo->getMTime()][] = $fileinfo->getFilename();
}

ksort($files);

Upvotes: 3

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