hsmyers@ubuntu:/usr$ perlbrew switch /usr/bin/perl
/usr/bin/perl is not installed
hsmyers@ubuntu:/usr$ which cpanm
/home/hsmyers/perl5/perlbrew/bin/cpanm
hsmyers@ubuntu:/usr$ sudo cpanm Chess::PGN::Moves
[sudo] password for hsmyers: 
Chess::PGN::Moves is up to date. (0.05)
hsmyers@ubuntu:/usr$ hash -r
hsmyers@ubuntu:/usr$ cpanm
Can't write to cpanm home '/home/hsmyers/.cpanm': You should fix it with chown/chmod first.
hsmyers@ubuntu:/usr$ sudo cpanm
Usage: cpanm [options] Module [...]

Try `cpanm --help` or `man cpanm` for more options.
hsmyers@ubuntu:/usr$ hash -r
hsmyers@ubuntu:/usr$ sudo cpanm
Usage: cpanm [options] Module [...]

Try `cpanm --help` or `man cpanm` for more options.


##</code><code>##

hsmyers@ubuntu:/usr$ perldoc Chess::PGN::Moves
No documentation found for "Chess::PGN::Moves".

##</code><code>##

hsmyers@ubuntu:/$ perlbrew list
  perl-5.8.1
* /usr/bin/perl (5.10.1)

##</code><code>##

hsmyers@ubuntu:/$ perlbrew install /usr/bin/perl
Unknown installation target "/usr/bin/perl", abort.
Please see `perlbrew help` for the insturction of install command.