You may also be interested in this example from the documentation for stat:

    $mode = (stat($filename))[2];
    printf "Permissions are %04o\n", $mode & 07777;
[download]

This gets the mode directly, and then uses printf to print it as an octal number.

Update: This example is from perl5.005_03's documentation. The documentation on PerlMonks is from 5.005_02.