Modifying the Debugger

     If you want to modify the debugger, copy perldb.pl from  the
     perl  library  to  your  current  directory and modify it as
     necessary.  (You'll also have to put  -I.  on  your  command
     line.)   You  can  do  some  customization  by  setting up a
     .perldb  file  which  contains  initialization  code.    For
     instance, you could make aliases like these:

         $DB'alias{'len'} = 's/^len(.*)/p length($1)/';
         $DB'alias{'stop'} = 's/^stop (at|in)/b/';
         $DB'alias{'.'} =
           's/^\./p "\$DB\'sub(\$DB\'line):\t",\$DB\'line[\$DB\'line]/';