Sounds tricky

As far as I understand this, you want to analyze what the program is doing but you don't want to run it.

Or you want to run it in a safe mode where any changes it might make are isolated from a real system - effectively running it in an emulated fashion - stepping through and saying what will happen without actually performing the steps of the program.

I don't know of anything that will do that so I'd probably start by doing this...

Working with a copy of the file on a non-production machine, I would read the code in depth and identify and research any code puzzling me. At this stage the Perl documentation would be indispensable.

If it uses modules then I'd be careful to try and understand how it declares instances and uses the methods in those modules and whether it used those modules in a non-standard way. I'd also want to understand what those modules do.

If it uses in-house proprietary modules, then I would have to seek documentation and/or advice, if any, for those modules.

By then I should be able to identify the areas where it might be changing the real time environment. I'm assuming this is the problem area for you.

Then I would test to check my research is correct. The extent to which you prepare for this is up to you. I have no idea whether the testing stage would require disconnection from the network or a complete backup of the test machine in case everything gets trashed but you may need to go to that level. Only you know that.

Running the code may involve providing some default values for some variables but by then I would have a good idea what was required.

In reply to Re: perl debugging problem by LesleyB
in thread perl debugging problem by perlplayer

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.