<?php
try {
$p = new Phar('/path/to/my.phar', 0, 'my.phar');
$p['myfile.txt'] = 'hi';
$file = $p['myfile.txt'];
echo $file->getCompressedSize();
} catch (Exception $e) {
echo 'Write operations failed on my.phar: ', $e;
}
?>
The above example will output: