materio-base-d7/sites/all/libraries/mailgun/vendor/clue/stream-filter/examples/base64_encode.php

<?php

// $ echo test | php examples/base64_encode.php | base64 --decode

require __DIR__ . '/../vendor/autoload.php';

// encoding requires buffering in chunks of 3 bytes each
$buffer = '';
Clue\StreamFilter\append(STDIN, function ($chunk = null) use (&$buffer) {
    if ($chunk === null) {
        return base64_encode($buffer);
    }
    $buffer .= $chunk;
    $len = strlen($buffer) - (strlen($buffer) % 3);
    $chunk = substr($buffer, 0, $len);
    $buffer = substr($buffer, $len);

    return base64_encode($chunk);
}, STREAM_FILTER_READ);

fpassthru(STDIN);