Beefy Boxes and Bandwidth Generously Provided by pair Networks
Your skill will accomplish
what the force of many cannot
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??

Oft times you'll invoke a CGI script, and while the script will in fact execute, it doesn't quite do what you were expecting. Ascertaining the nature of the problem can prove spectacularly frustrating when you have as many degrees of separation as you do in the scenario of invoking the script indirectly via a web browser. You type something into your browser, it sends a request to the server, the server invokes the script, takes back its output, and sends it back to the browser. There may even be additional intermediary steps that obscure the problem.

Being able to cut both the web browser and web server out of the picture, thus isolating the script, can be quite useful. This will enable you to see the pure, raw output of your script, including the HTTP headers, as well as give you all of the output of your script, even in the event of a crash... far more useful than just seeing "INTERNAL SERVER ERROR" and only being able to ascertain the direct cause of the script crash, as opposed to seeing all output that preceded the crash. Of course, to get the full picture you need to be able to send in the same form parameters that you were previously doing through the request originating from the browser.

To do this, you'll want to instantiate a CGI object with a file handle opened to a file that contains field/value pairs, or with STDIN and type in the values when you run the script.

use CGI; open(FILE, "<data.txt") or die "gah!"; my $query = CGI->new(FILE); ...

Where data.txt contains stuff like...

foo=bar baz=biz

This paradigm will aid in detection of the problem, potentially exposing previously hidden issues, as well as greatly expedite the run/debug/tweak cycle.


In reply to Interactive Command Line Form Parameter Debugging by skyknight
in thread CGI Help Guide by tachyon

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!
  • 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, 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, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • Outside of code tags, you may need to use entities for some characters:
            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.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others exploiting the Monastery: (9)
    As of 2014-07-22 23:44 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      My favorite superfluous repetitious redundant duplicative phrase is:









      Results (130 votes), past polls