#!/usr/bin/env php

<?php

function check_phone($s)
{
    $n = str_replace( ['-', ' '], '', $s);  //spaces and '-' can be put in so many ways, that it's better to ignore
                                            //them, rather than wonder about every possible (and valid) combination
                                            //note ugly two-element array here
    if ( preg_match( '/^\\(?\\+?[0-9]{2,3}\\)?[0-9]{7}([0-9]{2})?$/', $n ) == 1 )
    {
            //country/area code (which is optional) can be given in brackets () and prefixed with +
            //follwed by 7 digits (landline), plus 2 optional (mobile)
        echo("VALID $s [ aka $n ]\n");
        return 1;
    } else {
        echo("INVALID $s [ aka $n ]\n");
        return 0;
    }
}

$phone_array = array( '123456789', '(12)9009090', '900-900-900', '+12 900 29 29', 'i900900900', '900 0-00 290', '+900123123', '0+00 900 900', '(+90) 900 200 300', '+490 900 100 200');

foreach ($phone_array as $phone)
{
    check_phone($phone);
}

?>