Styjun

I'm trying to set up a script that will move files from in a particular directory to a specific subdirectory, depending on the prefix of the filename.

As it stands, I have two arrays, one set out as such:

$arr1 = array(

[12] => "prefix1", 
[34] => "prefix2"
)

etc etc, where the keys are user IDs from our database, and the values are the prefix of that user's email address.

The other is like so:

$arr2 = array(

["prefix1_filename.ext"] => "prefix1",
["prefix2_filename.ext"] => "prefix2"
)

And so on.

These arrays will not be the same length.

What I want to do is compare the two arrays, and where a value in arr1 matches a value in arr2, take the corresponding keys and push those to a new array that looks like this:

$arr3 = array(

[12] => "prefix1_filename.ext",
[34] => "prefix2_filename.ext"
)

This will then be used to move the files into a subdirectory named for the id - eg /foo/bar/12/prefix1_filename.ext, /foo/bar/34/prefix2_filename.ext etc etc.

I've tried using array_combine, but as the two are not the same length, an error results. I've also tried intersecting them, to no avail.

Can anyone point me towards a solution that will achieve this? I can flip the arrays to make the keys the values if that will make this simpler.

Many thanks in advance.

This can be done, with a bit of trickery.

First of all, let's take the values from $arr1 that are present in $arr2:

$isect1 = array_intersect($arr1, $arr2);

Then, get the opposite

$isect2 = array_intersect($arr2, $arr1);

Now we have keys from both arrays, but we want to sort them to ensure they're in the same order. We'll need to flip them first.

$sorted1 = array_sort(array_flip($isect1));
$sorted2 = array_sort(array_flip($isect2));

Now we have that, we can just combine them back

$arr3 = array_combine(array_values($sorted1), array_values($sorted2));

Demo out of the way, to cut down on the variable copying, we can do it in one line:

$arr3 = array_combine(array_values(array_sort(array_flip(array_intersect($arr1, $arr2)))), array_values(array_sort(array_flip(array_intersect($arr2, $arr1)))));

Phew. Got there in the end!

EDIT

Here's my Psy Shell output testing this, added some extra "non matching" values in to test the filtering:

>>> $arr1 = [12 => "prefix1", 34 => "prefix2", 99 => "some_other_prefix"];
=> [
 12 => "prefix1",
 34 => "prefix2",
 99 => "some_other_prefix",
 ]
>>> $arr2 = ["prefix1_filename.ext" => "prefix1", "prefix2_filename.ext" => "prefix2", "another_prefix_filename.ext" => "another_prexix"];
=> [
 "prefix1_filename.ext" => "prefix1",
 "prefix2_filename.ext" => "prefix2",
 "another_prefix_filename.ext" => "another_prexix",
 ]
>>> $arr3 = array_combine(array_values(array_sort(array_flip(array_intersect($arr1, $arr2)))), array_values(array_sort(array_flip(array_intersect($arr2, $arr1)))));
=> [
 12 => "prefix1_filename.ext",
 34 => "prefix2_filename.ext",
 ]

note : $arr2 can't be compared because difference of array keys

 <?php
 $arr1 = array(12=> "prefix1",34 => "prefix2");

 $arr3 = array(12 => "prefix_filename.ext",
 34 => "prefix2_filename.ext"
 );

 $arr2 = array(
 "prefix_filename.ext" => "prefix",
 "prefix2_filename.ext" => "prefix2"
 );


 $result=array_intersect($arr1,$arr2);
 print_r($result);
?>