This is Perl module App::vl.
App::vl installation is straightforward. If your CPAN shell is set up, you should just be able to do
% cpan App::vl
Download it, unpack it, then build it as per the usual:
% perl Makefile.PL % make && make test
Then install it:
% make install
Downloading the standalone executable
You can also copy the standalone executable to whatever location you'd like.
% curl -o vl -L http://bit.ly/App-vl % chmod +x vl
NOTE: Edit shebang if you don't have /usr/bin/env
App::vl documentation is available as in POD. So you can do:
% perldoc App::vl
App::vl is hosted on github http://github.com/bayashi/App-vl
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See perlartistic.
Dai Okabayashi <email@example.com>