lanx@nc10-ubuntu:~$ cat .perldb
sub afterinit { $DB::alias{ALIAS}='s/ALIAS/command/' }            

##</code><code>##

sub afterinit { 
 $DB::doccmd='perldoc';
 $DB::alias{doc}='s/doc/perldoc/'; 
}            

##</code><code>##

  DB<2> doc -f print

##</code><code>##

 lanx@nc10-ubuntu:~$ doc -k '=='