Using perl CGI.pm through multiple subroutines

Question

So I am working on a school project where I have been asked to write perl cgi script to create a social net site.

I have created multiple subroutines for different pages, but my problem is that when I try to execute each subroutine individually, it works fine, but when i try to run it though some other subroutine, it just redirects me to my first page.

For eg : This is my New User page code :

    #!/usr/bin/perl -w
    use CGI qw/:all/;
    use CGI::Carp qw/fatalsToBrowser warningsToBrowser/;
    my $cgi = new CGI;

    sub main() {
            print page_header();

            warningsToBrowser(1);

            first();

            page_trailer();
        }


    sub page_header {
            return header(-charset => "utf-8"),
                start_html(-title => 'Matelook',-style => "matelook.css"),
                body({-background =>"background.jpg"}),
                div({-class => "matelook_heading"}, "matelook");
        }

    sub page_trailer {
            my $html = "";
            $html .= join("", map("<!-- $_=".param($_)." -->\n", param())) if $debug;
            $html .= end_html;
            return $html;
        }

    sub new_user {
                  $fullname = param("fullname") || '';
                    $newun = param("newun") || '';
                    $newpass = param("newpass") || '';
                    $email = param("email") || '';
                    $program = param("program") || '';

                if(param("Save")){
                    $data = "full_name=$fullname \n 
                         username=$newun \n
                         password=$newpass \n
                         email=$email \n
                         program=$program \n";


                        $location = "dataset-medium/$newun";
                        mkdir $location, 0755;  
                        open($f,'>',"$location/user.txt");
                        print $f $data;
                        print $data,"\n";
                        print "Data Saved !! ";

                }

                else{
                     print start_form,"\n";
                        print "Enter Full Name :\n", textfield("fullname");
                        print "New Username :\n", textfield('newun'),"\n";
                        print "New Password :\n", textfield('newpass'),"\n";
                        print "Email:\n",textfield('email'),"\n";
                        print "Program:\n",textfield('program'),"\n";
                        print submit({-name =>"Save",-class => "matelook_button"});
                        print end_form,"\n";       
                }
            }

    sub first{
            if(param("New User")){
                new_user();
            }
            else{
                print start_form,"\n";
                   print submit({-class => "matelook_button_first ",-name => 'New User'}),"\n";
                print end_form,"\n";
            }
        }
    main();

if I try to call the same subroutine with a subroutine "first" and click the "Save" button, it redirects me to the "First" page through which I called the new_user.

Any help will be appreciated.

Thanks

Please provide a minimal *runnable* demonstration of the problem. — ikegami, Nov 01 '16 at 04:15
Also, start by adding `use strict; use warnings qw( all );`. You should be using this in every program. You have numerous scoping errors to fix, and who knows what else. — ikegami, Nov 01 '16 at 04:17
Hi, I have edited the program. See if you can help ? @ikegami — Utkarsh Atri, Nov 01 '16 at 04:21
As in, are you actually passing a `&New%20User=foo` param in your request? Try renaming it to `new_user` — xxfelixxx, Nov 01 '16 at 04:24
@ikegami I had forgotten to add #!/usr/bin/perl . Please try again as it works on my machine — Utkarsh Atri, Nov 01 '16 at 04:39
No, you forgot to include `main()` and `first()`. I've already fixed it. In the future, please post code you actually ran. Writing an answer. — ikegami, Nov 01 '16 at 04:40
Some strange practices in you code. `-w` on the shebang line was replaced by `use warnings` many years ago. You should add `use strict` too. And you create a `$cgi` variable that you never use - you can delete that line. — Dave Cross, Nov 01 '16 at 11:45

ikegami · Accepted Answer · 2016-11-01T05:03:30.337

1

Your program has the following structure:

sub new_user {
   if (param("Save")){
      save();
   } else {
      show_input_form();
   }
}

if (param("New User")){
   new_user();
} else {
   show_menu();
}

The problem is that the input form doesn't set pararm('New User'), so you don't end up in new_user when you click Save.

Solution 1:

Add a hidden input to the input form with name New User and value 1.

Solution 2:

Change

if (param("New User"))

to

if (param("New User") || param('Save'))

Solution 3:

Change the structure of the program to

if (param("New User")){
   show_input_form();
}
elsif (param("Save")){
   save();
}
else {
   show_menu();
}

edited Nov 01 '16 at 05:03

answered Nov 01 '16 at 04:35

ikegami

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Worked! Thanks a lot @ikegami – Utkarsh Atri Nov 01 '16 at 04:52
hey, I am getting confused in subroutines with arguments. How do I fix that ? @ikegami – Utkarsh Atri Nov 01 '16 at 06:39
1

@UtkarshAtri: "I am getting confused in subroutines with arguments. How do I fix that ?" It impossible for us to answer that question without reading your mind. Perhaps you could write a new question explaining your confusion. – Dave Cross Nov 01 '16 at 09:18

Using perl CGI.pm through multiple subroutines

1 Answers1