in reply to mod_perl and multi user environment - clashes with other users's data

Because print_response closed over the my $name that existed when the script was compiled. That my $name is different from the one in the second pass.

Solution 1: Use package (our) variables instead of lexical (my) variables for globals. 

#!/usr/cisco/bin/perl -w
use strict;

use CGI;

our $q;
our $name;

sub print_response {
    print "Content-type: text/plain\n\n";
    print "Thank you, $name!";
}

{
   local $q = CGI->new;
   local $name = $q->param('name');

   print_response( );
}

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Solution 2: Use arguments instead of global variables. 

#!/usr/cisco/bin/perl -w
use strict;

use CGI;

sub print_response {
    my ($name) = @_;
    print "Content-type: text/plain\n\n";
    print "Thank you, $name!";
}

{
   my $q = CGI->new;
   my $name = $q->param('name');

   print_response($name);
}

[download]

Update:

Solution 3: Use objects instead of global variables. 

#!/usr/cisco/bin/perl -w
use strict;

use CGI;

sub new {
   my ($class) = @_;

   my $q = CGI->new;
   my $name = $q->param('name');

   return bless({
      q    => $q,
      name => $name,
   }, $class);
}

sub print_response {
    my ($self) = @_;
    my $name = $self->{name};
    print "Content-type: text/plain\n\n";
    print "Thank you, $name!";
}

{
   my $self = __PACKAGE__->new();
   $self->print_response();
}

[download]

Replies are listed 'Best First'.
Re^2: mod_perl and multi user environment - clashes with other users's data
by rsennat (Beadle) on Dec 05, 2005 at 09:47 UTC
    hi,
    Even after using "our" keyword, im facing problem with my code. with that sample your solution works fine. but please check whats wrong in my code, 
    #! /usr/cisco/bin/perl -w

#use strict;
use CGI qw(:standard);
use CGI::Carp qw(warningsToBrowser fatalsToBrowser);
use HTML::Template;
use Data::Dumper;

use hiGuiStatus; # my own module

# send the obligatory Content-Type
print "Content-Type: text/html\n\n";

#$q = new CGI;
#print $q->Dump();


our $status = hiGuiStatus->new();
our $userid = $status->get_ldap_user_name();

print $userid;
my $err_msg;


($err_msg, %hoh) = $status->read_file($userid);
#print Dumper \%hoh;

if(param('sort'))
{
    my $sort_sel = param('sort_option');
    ($err_msg, @sort_keys) = $status->jobs_sort($sort_sel);
    #print $err_msg;
}


if(param('terminate'))
{
    my @del_ids = param('check_del');
    
    ($err_msg) = $status->jobs_terminate(\@del_ids, $userid, \%hoh);
    ($err_msg, %hoh) = $status->read_file($userid);
}


if(param('publish'))
{
    my $ddts = param('ddts_no');
    my @del_ids = param('check_del');

    $status->jobs_publish($ddts, \@del_ids);
}


if(param('delete'))
{
    my @del_ids = param('check_del');

    ($err_msg) = $status->jobs_delete(\@del_ids, $userid, \%hoh);
    ($err_msg, %hoh) = $status->read_file($userid);
}


@loop = $status->jobs_loop();
#print Dumper \@loop;

my $template = HTML::Template->new(filename => 'hiGuiStatus.tmpl');

# call param to fill in the loop with the loop data by reference.
$template->param(err_msg => $err_msg, job_loop => \@loop);

# print the template
print $template->output;

    [download]

    Basically this code does retrieve data from a text file for a particular user who has logged in and display it using HTML::Template.
    I used the keyword "our" and still face the problem of other user's data being displayed in my browser, ONLY IN mod_perl

    thanks
    rsennat
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