Rightly or wrongly, I use the debugger. I use it all the time to step through code that I have inherited. Along the way I have run across a few debugger idioms that have been invaluable to my code archiology.
Please respond and share your debugger idioms!
- Write intermediate data to a file
In some cases, while debugging, it is helpful to capture an intermediate data structure for reference. I find this particularly useful for dumping out xml content that is generated.
DB<3> open FH, ">/tmp/foo.txt"; DB<4> print FH "THIS IS AN EXAMPLE"; DB<5> print FH $user_id; DB<6> close FH
You can evaluate any valid perl expression with x while in the debugger. However you can also step into that expression using s. For example:
DB<6> s $profile->to_xml() main::((eval 35)[/usr/lib/perl5/5.6.1/perl5db.pl:1521]:3): 3: $profile->to_xml(); DB<<7>>
At this point, you will be stepping through the expression that was entered on the previous line.
Put the following expression somewhere in your code, run it in the debugger and the debugger will stop on the line immediately following it.
$DB::single = 1;
There are many more debugger idioms out there, what are yours?
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