Gossamer Forum: General: Perl Programming: Passing Variables in Perl/Tk???

Dec 10, 2002, 2:56 PM

Fat_N_Furry

Novice (18 posts)

Dec 10, 2002, 2:56 PM

Post #1 of 22

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Passing Variables in Perl/Tk???

Hello, all. I'm trying to pass a variable to one of my subroutines when my users hit a button, but it always complains. Something about an "undefined subroutine".

Here's my code for the -command attribute of the button:

-command => \&subroutine("variable_to_be_passed"),

sub subroutine
{
# Do stuff with the variable here...
}

If you need additional information about my program, let me know. I'm a newbie, so be gentle when you reply. Wink

Also - if you didn't catch the thread title, this is in Perl/Tk.

Thanks for any help!
Furry

P.S. This forum is awesome. Love the smileys and icons and especially spell check. Smile

Dec 10, 2002, 9:10 PM

Stealth

Veteran (17240 posts)

Dec 10, 2002, 9:10 PM

Post #2 of 22

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Re: [Fat_N_Furry] Passing Variables in Perl/Tk??? In reply to

You should consider using CGI.pm to pass parameters from your form to your script.
========================================
Buh Bye!

Cheers,
Me

Dec 11, 2002, 8:21 AM

Fat_N_Furry

Novice (18 posts)

Dec 11, 2002, 8:21 AM

Post #3 of 22

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Thanks for replying! In reply to

Well, I would except I'm not trying to pass it from a form. I'm trying to pass the variables from one part of my program to a sub. Any suggestions?

Thanks again for your reply.

Furry

Dec 11, 2002, 8:24 AM

yogi

Veteran (2199 posts)

Dec 11, 2002, 8:24 AM

Post #4 of 22

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Re: [Fat_N_Furry] Thanks for replying! In reply to

Can you do

perl -c filename.pl

on your file, and tell us what the output is?

Ivan
-----
Iyengar Yoga Resources / GT Plugins

Dec 11, 2002, 8:25 AM

Paul

Veteran (19537 posts)

Dec 11, 2002, 8:25 AM

Post #5 of 22

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Re: [Fat_N_Furry] Thanks for replying! In reply to

Quote:

Something about an "undefined subroutine".

You need to be specific in order to receive accurate assistance :)

Dec 11, 2002, 8:52 AM

Fat_N_Furry

Novice (18 posts)

Dec 11, 2002, 8:52 AM

Post #6 of 22

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Re: [yogi] Thanks for replying! In reply to

In Reply To:

Can you do

perl -c filename.pl

on your file, and tell us what the output is?

calculator.txt syntax OK

Thanks for showing me that, though. I had no idea that perl had a debugging option.

In Reply To:

Quote:

Something about an "undefined subroutine".

You need to be specific in order to receive accurate assistance :)

Tk::Error: Undefined subroutine &main::1 called at c:/gnu_programs/Perl/site/lib/Tk.pm line 228.
\1
Tk callback for .button
Tk::__ANON__at c:/gnu_programs/Perl/site/lib/Tk.pm line 228
Tk::Button::butUp at c:/gnu_programs/Perl/site/lib/Tk/Button.pm line 111
<command bound to event>

Specific enough for ya? Wink

Thanks for all your time,
Furry

Dec 11, 2002, 9:11 AM

Andy

Veteran / Moderator (18441 posts)

Dec 11, 2002, 9:11 AM

Post #7 of 22

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Re: [Fat_N_Furry] Thanks for replying! In reply to

Could you post a link to a .txt version of the script (i.e something that wont be parsed as a .cgi script)?

Cheers

Andy (mod)
andy@ultranerds.co.uk

Dec 11, 2002, 11:22 AM

Fat_N_Furry

Novice (18 posts)

Dec 11, 2002, 11:22 AM

Post #8 of 22

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Re: [Andy] Thanks for replying! In reply to

Sure - here you go - this is an example of what I'm trying to do. The reason I don't post the actual file is that I changed the code to get around not being able to pass variables to subroutines. (I have a different subroutine for each button Unimpressed

)

Last edited by:

Fat_N_Furry: Dec 11, 2002, 11:24 AM

Dec 11, 2002, 11:30 AM

Paul

Veteran (19537 posts)

Dec 11, 2002, 11:30 AM

Post #9 of 22

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Re: [Fat_N_Furry] Thanks for replying! In reply to

So where are MainWindow and MainLoop defined?

Dec 11, 2002, 11:32 AM

yogi

Veteran (2199 posts)

Dec 11, 2002, 11:32 AM

Post #10 of 22

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Re: [Paul] Thanks for replying! In reply to

You probably want:

Code:
sub pass { 
        my $char = shift 
        printf($char); 
}

i.e. without the ($char) thingy.

Ivan
-----
Iyengar Yoga Resources / GT Plugins

Last edited by:

yogi: Dec 11, 2002, 11:47 AM

Dec 11, 2002, 11:36 AM

Fat_N_Furry

Novice (18 posts)

Dec 11, 2002, 11:36 AM

Post #11 of 22

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Re: [Paul] Thanks for replying! In reply to

Code:
    use Tk; 
######################## 
#   MainWindow Here:   # 
######################## 

    my $main = MainWindow->new( 
                              -background => 'blue', 
                              ); 

    $equals = $main -> Button( 
                            -text    => '=', 
                            -justify => 'center', 
                            -width   => '2.5', 
                            -height  => '1.5', 
                            -command => \&pass('1'), 
                            -activebackground => 'skyblue', 
                          ) -> pack( 
                                    -expand => yes, 
                                    -fill => 'both', 
                                   ); 

    $main -> title("Tk Calculator"); 

###################### 
#   MainLoop Here:   # 
###################### 

    MainLoop(); 

    sub pass($char) 
    { 
        printf($char); 
    }

Last edited by:

Fat_N_Furry: Dec 11, 2002, 11:37 AM

Dec 11, 2002, 11:40 AM

Fat_N_Furry

Novice (18 posts)

Dec 11, 2002, 11:40 AM

Post #12 of 22

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Re: [yogi] Thanks for replying! In reply to

In Reply To:

You probably want:

Code:
sub pass ($char)
    { 
        printf($char); 
    }

i.e. without the ($char) thingy.

I believe I've tried both ways; I'll try that way again. BTW - you access that via the @_ array, right?

Dec 11, 2002, 11:42 AM

Paul

Veteran (19537 posts)

Dec 11, 2002, 11:42 AM

Post #13 of 22

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Re: [Fat_N_Furry] Thanks for replying! In reply to

Dec 11, 2002, 11:42 AM

Fat_N_Furry

Novice (18 posts)

Dec 11, 2002, 11:42 AM

Post #14 of 22

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Re: [Fat_N_Furry] Thanks for replying! In reply to

Yeah - I get the same result without the ($char).

Dec 11, 2002, 11:45 AM

Fat_N_Furry

Novice (18 posts)

Dec 11, 2002, 11:45 AM

Post #15 of 22

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Re: [Paul] Thanks for replying! In reply to

In Reply To:

Whatya mean "?" ?

Dec 11, 2002, 11:59 AM

Paul

Veteran (19537 posts)

Dec 11, 2002, 11:59 AM

Post #16 of 22

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Re: [Fat_N_Furry] Thanks for replying! In reply to

I mean why did you just paste the code in reply to my question.

Dec 12, 2002, 11:43 AM

Fat_N_Furry

Novice (18 posts)

Dec 12, 2002, 11:43 AM

Post #17 of 22

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Re: [Paul] Thanks for replying! In reply to

You asked where MainWindow and MainLoop were defined - I just pointed them out for you. Smile

Last edited by:

Fat_N_Furry: Dec 12, 2002, 11:44 AM

Dec 12, 2002, 11:54 AM

Paul

Veteran (19537 posts)

Dec 12, 2002, 11:54 AM

Post #18 of 22

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Re: [Fat_N_Furry] Thanks for replying! In reply to

They aren't defined - you call them but where are they implemented?...are they exported from Tk?

Last edited by:

Paul: Dec 12, 2002, 11:54 AM

Dec 13, 2002, 6:43 PM

Fat_N_Furry

Novice (18 posts)

Dec 13, 2002, 6:43 PM

Post #19 of 22

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Re: [Paul] Thanks for replying! In reply to

Yeah - they're Tk things. MainWindow defines the window, MainLoop keeps the window open.

Dec 20, 2002, 3:14 PM

utinni

Novice (11 posts)

Dec 20, 2002, 3:14 PM

Post #20 of 22

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Re: [Fat_N_Furry] Passing Variables in Perl/Tk??? In reply to

Hi, just found this thread when googling for Perl/Tk stuff.

-command => \&subroutine("variable_to_be_passed"),

You can't do it like that : it parses as

-command => \( &susubroutine("variable_to_be_passed") ),

i.e. it immediately calls subroutine, which returns 1 (the return value of the last command in the subroutine, print) and then the \ gets a reference to that 1, so you end up with

-command => \1,

What you really want is

-command => sub { subroutine("variable_to_be_passed") }

--

Utinni!

Dec 22, 2002, 8:10 AM

Fat_N_Furry

Novice (18 posts)

Dec 22, 2002, 8:10 AM

Post #21 of 22

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Re: [utinni] Passing Variables in Perl/Tk??? In reply to

Thanks dude! I appreciate it. I have to go to church now, but I'll try it when I get home. Smile

Thankyou all!
Furry

Dec 22, 2002, 10:36 AM

Fat_N_Furry