How to open an URL with variable in CGI?

msomanat has asked for the wisdom of the Perl Monks concerning the following question:

Hi perl monks, I am very new to CGI scripting, and stuck up here. I am using an HTML to POST some data, and analyzing it at CGI script. With the output I get after analysis, I need to open another cgi at a different server. This is what I have tried.

print $q->start_form(
-name    => 'main_form2',
-method  => 'POST',
-action  => 'http://xxx.com/cgi-bin/perforce?&Submit=describe&changenu
+m=$1',
-target  => '_blank',
);
print $q->submit(
-name     => 'submit_form2',
-value    => 'See the change',
);
print $q->end_form;
[download]

I have two problems here. 1) I cannot pass a variable. $1 won't work 2) If I pass it hardcoded, it would work, but the variables after 'perforce?' are not considered, until I refresh the newly opened page. This is my first CGI script,and need your help badly. Thanking in advance, Manoj

Comment on How to open an URL with variable in CGI? Download Code

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Re: How to open an URL with variable in CGI? by 1nickt (Canon) on Jul 27, 2015 at 20:52 UTC
Remove the first `&` from the query string; that character separates key=value pairs and you have nothing in front of it. Your `$1` is not being evaluated because it is inside single quotes. Also, where do you set `$1`? It's usually set by Perl as a regex capture... Update: got back to PC; improved formatting The way forward always starts with a minimal test.	[reply] [d/l] [select]
Re: How to open an URL with variable in CGI? by tangent (Parson) on Jul 27, 2015 at 20:53 UTC
I assume that `$1` is the result of a regular expression match. If not you should change it to a textual name. The reason the target url is not recognising the query parameters is that this is a POST request. You need to add some hidden fields to pass those parameters: `my $changenum = $1; print $q->start_form( -name => 'main_form2', -method => 'POST', -action => 'http://xxx.com/cgi-bin/perforce', -target => '_blank', ); print $q->hidden( -name => 'Submit', -value => 'describe', ); print $q->hidden( -name => 'changenum', -value => $changenum, ); print $q->submit( -name => 'submit_form2', -value => 'See the change', ); print $q->end_form;` [download]	[reply] [d/l] [select]
Re: How to open an URL with variable in CGI? by marinersk (Priest) on Jul 27, 2015 at 23:26 UTC
I'm guessing (because it doesn't look like you posted a fully functional example), but -- if you intend `$1`to be the first parameter sent to the subroutine which contains the code you posted, you need to grab that in advance: `sub doMyThing { my ($changeNumber, @otherParameters) = @_; : : print $q->start_form( -name => 'main_form2', -method => 'GET', -action => "http://xxx.com/cgi-bin/perforce?Submit=describe\& +changenum=$changeNumber", -target => '_blank', ); : : return; }` [download]	[reply] [d/l] [select]