How to watch a reference in the debugger?

saintmike has asked for the wisdom of the Perl Monks concerning the following question:

Is there a way in perl's debugger to watch a reference or a memory location? Let's say, with code like

1:    my %hash = (a => 'b');  # Watch %hash
2:
3:    my $ref = \%hash;       # Breakpoint!
4:    ### ... some code ...
5:    my $otherref = \%hash;  # Breakpoint!
6:    my $yetanotherref = $otherref; # Breakpoint!
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is there a way in line 1 (or 3) to set a watch point in the debugger so that whenever %hash is referenced somehow (for reading or writing), the debugger stops?

Or is there a way to say "whenever you reference HASH(0x81049b0), let the debugger stop"?

Any help apprechiated.

Comment on How to watch a reference in the debugger? Download Code

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Re: How to watch a reference in the debugger? by Old_Gray_Bear (Bishop) on Jun 06, 2004 at 18:50 UTC
Take a look at the debugger 'w' command -- set global watch point. (Sorry, I don't know which release of Perl brought it in; it's in the 5.8.x versions and I don't remenber it using it with 5.6.x.) I don't know how it will work against a reference, you may have to watch the base variable. (`'w %hash'`rather than `'w \%hash'`). ---- I Go Back to Sleep, Now. OGB	[reply] [d/l] [select]
Re: How to watch a reference in the debugger? by ambrus (Abbot) on Jun 06, 2004 at 19:14 UTC
IIRC someone has mentioned a module that does this kind of debugging with tied variables. Try to super-search for it. Update: here's it: Debugging with tied variables	[reply]