Re: "omniscient debugging" for Perl

A perl tool that sorta kinda works this way is Devel::Trace

    perl -d:Trace program.pl
[download]

Mind you, it only prints out the flow of execution; it doesn't actually let you inspect variables or anything like that. It's still pretty useful, though. I just wish I could find a way to switch it on and off at runtime under mod_perl. :)

Michael

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Re^2: "omniscient debugging" for Perl by pemungkah (Priest) on Jul 05, 2005 at 23:34 UTC
A quick glance at the source shows that MJD is using the global `$TRACE` to decide if the trace output should be printed. Just set `$TRACE = 0` at the top of your program, set it to a non-zero value when trace should start, and back to zero again when you want it off again. Simple.	[reply] [d/l] [select]
Re^3: "omniscient debugging" for Perl by magog (Beadle) on Jul 06, 2005 at 19:22 UTC
Thanks for the tip, pemungkah! The other problem is how to get the -d:Trace option to work under mod_perl. Here's how to do it: Add the following section to httpd.conf: `<Perl> $Devel::Trace::TRACE = 0; </Perl>` [download] And start the server like this: `$ PERL5OPT=-d:Trace sudo /etc/init.d/httpd restart` [download] Then in your code you can write: `$Devel::Trace::TRACE = 1; # some buggy code $Devel::Trace::TRACE = 0;` [download] Problems: Server spits out a mess of trace info before $TRACE is set to 0 Trace info (and there's a lot of it) goes to the error log, which is hard to manage I think I'll try making a patch to allow turning off $TRACE via the command line, and to allow sending the trace info to a different file. Michael	[reply] [d/l] [select]