[PLUG] Determining Why Perl Script Fails

[Dale Snell]

On Wed, 6 Aug 2014 07:39:16 -0700 (PDT)
Rich Shepard <rshepard at appl-ecosys.com> wrote:

>    After changing logwatch.pl to send its reports by mail the script
> worked for a few days. Today it failed completely. That is, running
> from the command line produces no output in the virtual terminal so
> apparently there's nothing to report via mail either.
>
>    Running logwatch.pl via strace produces a 600+K output file with
> appropriate pauses when running while the script reads and summarizes
> log files. The strace output tells _me_ nothing.
> 
>    Considering that logwatch.pl has run faithfully each day for years
> I suspect that there's something in the upgrade to version 7.4.0 that
> is at the root of the problem.
> 
>    There are many perl mongers amoung you and I would appreciate
> guidance on determing where the script fails and advice on how to fix
> it ... finally.

I'm not a Perl monger, but I have a suggestion or two:

Try running the strace output file through grep, looking for the
string "ERR" or "ENO".  It's a long shot, but it can't hurt to
try.

What options did you specify for strace (it has so very many)?  It
can make quite a difference in the output.

Also, you might try running logwatch with the "--debug n" option,
where "n" is an integer running from 0 to 100.  I've never done
this, and the man page does say it will _really_ clutter up your
output, but what the hey?  I'd try something low, like 10, just to
start.


Sorry I couldn't be of more help.

--Dale

--
Bring on the lightning!  We'll build a monster for fun!
Bring on the lightning!  We'll turn him loose when we're done!
It's very frightening -- See how the villagers run!
Pull that switch and catch the lightning -- Before the storm is done!
  -- from "Girl Genius," sung to the tune of the "Beer Barrel Polka"
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