Test::Output provides a simple interface for testing output sent to
STDOUT or STDERR. A number of different utilities are included to try
and be as flexible as possible to the tester.

Originally this module was designed not to have external requirements,
however, the features provided by Sub::Exporter over what Exporter
provides is just to great to pass up.

Test::Output ties STDOUT and STDERR using Test::Output::Tie.

WWW: https://metacpan.org/release/Test-Output