use IO qw(Handle File); # loads IO modules, here IO::Handle, IO::File
use IO; # DEPRECATED
DESCRIPTION"IO" provides a simple mechanism to load several of the IO modules in one go. The IO modules belonging to the core are:
IO::Handle IO::Seekable IO::File IO::Pipe IO::Socket IO::Dir IO::Select IO::Poll
Some other IO modules don't belong to the perl core but can be loaded as well if they have been installed from CPAN. You can discover which ones exist by searching for ``^IO::'' on http://search.cpan.org.
For more information on any of these modules, please see its respective documentation.
use IO; # loads all the modules listed below
The loaded modules are IO::Handle, IO::Seekable, IO::File, IO::Pipe, IO::Socket, IO::Dir. You should instead explicitly import the IO modules you want.