Beefy Boxes and Bandwidth Generously Provided by pair Networks
Keep It Simple, Stupid

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

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

  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or or How to display code and escape characters are good places to start.
Log In?

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

How do I use this? | Other CB clients
Other Users?
Others avoiding work at the Monastery: (2)
As of 2021-09-22 02:31 GMT
Find Nodes?
    Voting Booth?

    No recent polls found