Generate Data Interchange Format from key value array source

dif.php

<?php

$data = [
    [
        'hello' => 'world',
        'world' => 'hello',
    ],
    [
        'hello' => '12387293871293847123894712342134',
        'world' => '12387293871293847123894712342134',
    ],
    [
        'hello' => '12387293871293847123894712342134',
        'world' => 'zxcv',
    ],
];

function make_dif($key_value_pairs)
{
    $size = 0;
    $output = tmpfile();

    $write = function (...$values) use ($output, &$size) {
        foreach ($values as $value) {
            $size += fwrite($output, $value . "\r\n");
        }
    };

    $write_row = function ($row) use ($write) {
        $write('-1,0', 'BOT');
        foreach ($row as $value) {
            $write('1,0', '"' . addcslashes($value, '"') . '"');
        }
    };

    $write('TABLE', '0,1', '"PHP"');
    $write('VECTORS', "0,0", '""');
    $write('TUPLES', "0,0", '""');
    $write('DATA', '0,0', '""');

    $first = true;

    foreach ($key_value_pairs as $row) {
        if ($first) {
            $write_row(array_keys($row));
            $first = false;
        }
        $write_row($row);
    }

    $write('-1,0', 'EOD');

    rewind($output);
    return [$output, $size];
}

ob_start("ob_gzhandler");
list($out, $size)= make_dif($data);
header('Content-Type: text/plain; charset=UTF-8');
header("Content-Length: $size");
header('Content-Disposition: attachment; filename="export.dif"');
fpassthru($out);