in reply to
Re^2: selecting from a number of different input sources.
in thread selecting from a number of different input sources.
It's not immediately clear from the docs, but just saying use IO::Handle entitles you to call IO::Handle methods on normal file handles like your already opened $fh. In other words, your snippet could be simplified as follows:
open (my $fh, '<', $FILE) or die $!;
# then simply call method from IO::Handle
This doesn't answer the question how to make a socket out of a regular file, but I thought it's worth mentioning nevertheless...