cgi session

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

Hi, i am trying to implement user sessions in my web application to add security and enable information to be passed from an inital form to mysql queries in later forms. I have been using the following code

use CGI::Session;
use CGI;

#set up a session
$cgi = CGI->new;
$session = CGI::Session->new("driver:File", $cgi, {Directory=>"./tmp"}
+);
$sid = $session->id();

$cookie = $cgi->cookie(CGISESSID => $session->id);
print $cgi->header( -cookie=>$cookie );
$sid = $cgi->cookie("CGISESSID") || undef;
$session = new CGI::Session(undef, $sid, {Directory=>'/tmp'});
[download]

However this is not working, here are a few of the errors that I am getting

Global symbol "$cgi" requires explicit package name at /....ls/result.
+cgi line 49.
Global symbol "$session" requires explicit package name at /....ls/res
+ult.cgi line 50.
Global symbol "$cgi" requires explicit package name at /....ls/result.
+cgi line 50.
Global symbol "$sid" requires explicit package name at /....ls/result.
+cgi line 51.
Global symbol "$session" requires explicit package name at /....ls/res
+ult.cgi line 51.
Global symbol "$cookie" requires explicit package name at 
/....ls/result.cgi line 53.
Global symbol "$cgi" requires explicit package name at /....ls/result.
+cgi line 53.
[download]

Can anybody see why this is not working? Thanks

Comment on cgi session Select or Download Code

Replies are listed 'Best First'.
Re: cgi session by andyford (Curate) on Dec 11, 2006 at 21:27 UTC
Looks like you need to use "my" to scope your variables. `use CGI::Session; use CGI; #set up a session my $cgi = CGI->new; my $session = CGI::Session->new("driver:File", $cgi, {Directory=>"./tm +p"}); my $sid = $session->id(); my $cookie = $cgi->cookie(CGISESSID => $session->id); print $cgi->header( -cookie=>$cookie ); $sid = $cgi->cookie("CGISESSID") \|\| undef; $session = new CGI::Session(undef, $sid, {Directory=>'/tmp'});` [download] non-Perl: Andy Ford	[reply] [d/l]
Re^2: cgi session by Anonymous Monk on Dec 11, 2006 at 22:06 UTC
Thanks andy, that seemed to work. Would someone be able to give me a quick explanation of what this actually does, i pieced it together from online examples and trial and error but dont fully understand how it works. Thanks again	[reply]
Re^3: cgi session by Joost (Canon) on Dec 11, 2006 at 22:23 UTC
See perlfaq7 on lexical vs global variables and strict. Basically, if you `use strict` (and you should) variables declared with "my" can only be used from the declaration on until the end of the scope they're declared in: `sub mysub { my $var1 = 1; # here you can use $var1 } $var1 = "boo"; # compile error: there is no $var1 declared in this sco +pe.` [download] Using "my" (lexical) variables together with "strict" will significantly reduce the risk of typos or modifying "unrelated" variables. "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply] [d/l] [select]