File::chmod is a utility that allows you to bypass system calls or bit
processing of a file's permissions. It overloads the chmod() function with its
own that gets an octal mode, a symbolic mode (see below), or an "ls" mode (see
below). If you wish not to overload chmod(), you can export symchmod() and
lschmod(), which take, respectively, a symbolic mode and an "ls" mode.

WWW: https://metacpan.org/dist/File-chmod