This is Perl module PerlX::Range. INSTALLATION PerlX::Range installation is straightforward. If your CPAN shell is set up, you should just be able to do % cpan PerlX::Range Download it, unpack it, then build it as per the usual: % perl Makefile.PL % make && make test Then install it: % make install DOCUMENTATION PerlX::Range documentation is available as in POD. So you can do: % perldoc PerlX::Range to read the documentation online with your favorite pager. Kang-min Liu