*Here is a simple example*
<?php
$zp = zip_open('file.zip');

while ($file = zip_read($zp)) {
    echo  zip_entry_name($file).PHP_EOL;
}
?>

The output will be something similar to:

myfile.txt
mydir/

Note: Only the first 65535 entries will be returned, even if your archive contains more entries. See https://bugs.php.net/bug.php?id=59118 for details.