Problem with CGI.pm redirects

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

Hi all

I have a simple perl cgi script which redirects quite happily:

#!C:\perl\bin\perl.exe -wT
use strict; 
use CGI qw/:standard/; 
my $cgi = new CGI; 
print $cgi->redirect( -uri => 'http://perl.about.com/' );
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trying to do the same in another script (relevant bits below)

if ($match==1) {
    my $r=new CGI;
    print $r->redirect( -uri => 'http://perl.about.com/' );
}
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results in a web page with my debug prints in which says

Got the following headers:
HTTP_REMOTE_USER: setheri
HTTP_HOST: localhost
HTTP_USER_AGENT: Fiddler
sid is setheri


Entering user test

Check of hash

sid2 is setheri

testing for existence

Item is setheri
we have a match

Status: 302 Found
Location: http://perl.about.com/
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The script basically gets the HTTP header value REMOTE_USER and if that is in a given list redirects. Don't ask - forced to do it that way by system restrictions. Can anyone shed any light as to why the second redirect does not work?

Many thanks

Comment on Problem with CGI.pm redirects Select or Download Code

Replies are listed 'Best First'.
Re: Problem with CGI.pm redirects by Corion (Patriarch) on Jun 06, 2011 at 14:43 UTC
Your debug `print`s confuse the webserver. Everything that you print to STDOUT goes to the client, and if the client does not see a HTTP header first, it assumes that it will get served plain text. Which is what happens with your output - at the bottom, there is the correct and expected `Status: 302` line and the new location header. To solve this, don't output anything before printing the `Status:` line.	[reply] [d/l] [select]
Re^2: Problem with CGI.pm redirects by moritz (Cardinal) on Jun 06, 2011 at 14:49 UTC
... or print your debug output to STDERR. warn does that by default. If you use Apache, the STDERR output of the script can be found in the error.log of your virtual host (typically `/var/log/apache2/yourhost/error.log`). Perl 6 - second systems done right	[reply] [d/l]
Re^3: Problem with CGI.pm redirects by stevee (Acolyte) on Jun 06, 2011 at 15:21 UTC
Many thanks both, works a treat! And the tip about warn is very useful. Stevee	[reply]


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