PHP double sort array based on substring

Question

I am building a custom switch manager for work, my current issue is more an aesthetic one but I think it is a good learning experience. I have posted the array below for clarity:

Array
(
    [1] => FastEthernet0/1
    [10] => FastEthernet0/10
    [11] => FastEthernet0/11
    [12] => FastEthernet0/12
    [13] => FastEthernet0/13
    [14] => FastEthernet0/14
    [15] => FastEthernet0/15
    [16] => FastEthernet0/16
    [17] => FastEthernet0/17
    [18] => FastEthernet0/18
    [19] => FastEthernet0/19
    [2] => FastEthernet0/2
    [20] => FastEthernet0/20
    [21] => FastEthernet0/21
    [22] => FastEthernet0/22
    [23] => FastEthernet0/23
    [24] => FastEthernet0/24
    [3] => FastEthernet0/3
    [4] => FastEthernet0/4
    [5] => FastEthernet0/5
    [6] => FastEthernet0/6
    [7] => FastEthernet0/7
    [8] => FastEthernet0/8
    [9] => FastEthernet0/9
    [25] => Null0
)

On our bigger switches I am using asort($arr); to get GigabitEthernet1/1 to come before 2/1, etc...

My goal is to sort on the interface number (part after '/') so that 1/8 comes before 1/10.

Could someone point me in the right direction, I want to work for the results but I am not familiar enough with PHP to know exactly where to go.

Notes: On out larger multi-module switches the IDs are not in order so a sort on $arr[key] won't work.

Answer 1

You can use the flag while using asort(), like below.

asort($arr, SORT_NATURAL | SORT_FLAG_CASE);print_r($arr);

It will print/sort the data as yo need.

Answer 2

The SORT_NATURAL and SORT_FLAG_CASE requires v5.4+.

If you're using an older version of PHP, you could do it with uasort and a custom comparison callback function.

$interfaces = array(...);
$ifmaj = array();
$ifmin = array();
$if_cmp = function ($a, $b) {
    list($amaj,$amin) = split('/',$a);
    list($bmaj,$bmin) = split('/',$b);
    $maj = strcmp($amaj,$bmaj);
    if ($maj!=0) return $maj;
    //Assuming right side is an int
    return $amin-$bmin;
};
uasort($interfaces, $if_cmp);