In light of the consideration: "Is that a link to pirated content?"

The code (tetris.pl) is part of the content of the book Advanced Perl Programming (Chapter 15: GUI Example: Tetris).

O'Reilly freely provides example code from the book in both .tar.gz and .zip formats. This specific script is in examples/GUI/tetris.pl.

Be aware this book was published in 1997. While I couldn't find a reference to a specific Perl version used for the code examples, it must be earlier than Perl v5.5 which was released in 1998 (see perlhist).