egor_nullptr

select
    user_id, count(*) as count, group_concat(product_id) as products 
from wishlist
group by user_id;

function combinations($words)
{
    if (count($words) == 1) {
        return [$words];
    };

    $combinations = [];
    $i = 0;

    do {
        $first_word = array_shift($words);
        foreach (combinations($words) as $cmb) {
            $combinations[] = array_merge([$first_word], $cmb);
        };
        array_push($words, $first_word);
    } while (++$i < count($words));

    return $combinations;
};

$combinations = combinations(explode(' ', 'word1 word2 word3 word4'));

print_r($combinations);

#!/usr/bin/env bash
for fname in `ls`; do
    new_name=`echo $fname | sed s/й/и/g`
    mv $fname $new_name
done