in reply to Using File::Tail::select with STDIN?

You can try opening and reading /dev/stdin or /proc/self/fd/0 on UNIX-like systems (at least on GNU/Linux).

Another way is to use fork to process your file and the command line (see Term::ReadLine, Term::ReadKey etc.) in separate processes.

Sorry if my advice was wrong.

In Section Seekers of Perl Wisdom