All those who can't install perldoc, or other modules, and want to know what modules are available (CPAN or otherwise), the following works for linux and Mingw32/64:
grep -RhIP '^package [A-Z][\w:]+;' `perl -e 'print join " ",@INC'` | sed 's/package //' | sort | uniq
Yes, it's messy.  Yes, it probably reports more than you want.  But if you pipe it into a file, you can easily check for, say, which dbm interfaces are present:
 grep -RhIP '^package [A-Z][\w:]+;' `perl -e 'print join " ",@INC'` | sed 's/package //' | sort | uniq > modules-installed
 cat modules-installed | grep -i dbm 
AnyDBM_File;
Memoize::AnyDBM_File;
Memoize::NDBM_File;
Memoize::SDBM_File;
WWW::RobotRules::AnyDBM_File;
Which is why I ended up on this page (disappointed)
(I realise this doesn't answer the OP's question exactly, but I'm posting it for anybody who ended up here for the same reason I did.  That's the problem with stack*** it's almost imposisble to find the question you're asking, even when it exists, yet stack*** is nearly always google's top hit!)