There's a The Effective Perler article on custom tracing entitled Trace your Perl programs that you might find useful, particularly the last example.

To summarize...

• Under the -d switch, perl calls &DB::DB before each statement
• You can write your own tracer (e.g., Devel::Foo) to define your own &DB::DB that excludes third-party modules, and run it via -d:Foo
.

Thanks for the links.

I was aware that I can overload internal DB:: functions, (sorry for not mentioning)

I just had the hope that I could solve this with an *option* (CLI or .perldb).

Actually in this case I think I have to overload DB::sub like demonstrated in perldebguts

      {
        package DB;
        sub DB  {}
        sub sub {print ++$i, " $sub\n"; &$sub}
      }
[download]

Thanks anyway! :)
---The Perlman

package Foo;

use strict;
use warnings;
use Aspect;
use Aspect::Library::Trace; 
use Data::Dumper::Concise;

aspect Trace => call qr/^Foo::/;

sub a {
    my($var) = @_;
    b(@_);
}
 
sub b {
    my($var) = @_;
    return map( {$_ + 1;} @_ );
}
print Dumper( a(qw[1 2 3]) );
[download]

Set a breakpoint and then continue

• perldebtut
• http://drdobbs.com/184404744 # Using the Perl Debugger | Dr Dobb's
• http://www.shlomifish.org/lecture/Perl/Newbies/lecture2/debugger/breakpoints.html
• http://www.linuxjournal.com/article/2484 # The Perl Debugger | Linux Journal
• Specifying a Filename in a Breakpoint in the Perl Debugger
• Using the Perl Debugger (-d)

Sorry, this question has nothing to do with breakpoints.
---The Perlman