Generate checksums.txt

checksums.php

<?php

$dir = getcwd();

$algos = ['md5', 'sha1', 'sha256', 'sha512'];

$files = explode(',', $argv[1]);

$lines = '';
foreach ($files as $file) {
    if (file_exists("$dir/$file")) {
        foreach ($algos as $algo) {
            $hash = hash_file($algo, "$dir/$file");
            $lines .= $algo . ': ' . $hash . "\n";
        }
    }
}

file_put_contents('checksums.txt', $lines);
echo $lines;