I have been using Perl for a while, but have recently started using the Perl Tk module. I am trying to make a GUI that will ask for a bunch of information and then output it to a file, among other things. (Actually, I am trying to update a Perl program that does this via text inquiries in a command line.) I have successfully added Radiobuttons, text Entry and a regular Button to close the window and print out values at the end. I am stuck on trying to use the Button to call a subroutine that will send a value back to the main program.

I want to use a button to call a subroutine that will use ChooseDirectory to select a subdirectory and send it back to the main program. I tried several variations on the -command value, but none of them worked. If I put ChooseDirectory in the main window, instead of calling it from a button, it pops up before the general window asking for other information. It does send the correct information though.

I am copying some code here. This is for a smaller program that only tries to ask for the directory. Thanks for any help. 

# Test to enter select directory with gui

# Good to use next 3 lines for all perl programs.
#! /usr/bin/perl 
use warnings;
use strict;

# Use Tk module for gui and create window
use Tk;
my $mw = new MainWindow;
use Encode; #so can read directories

#Button to open directory and see tissue types
my $tissue="plasma";#default value
my $tissue_but = $mw -> Button(-text => 'Tissue Type', -command =>sub 
+{select_tissue()});
$tissue_but->grid(-row=>3,-column=>1);
#-command => [ sub { ... }, arg1, arg2, ... ]
#Button to close gui window
my $but=$mw -> Button(-text => 'Data Entry Complete', -command =>sub {
+do_end()});
$but->grid(-row=>10,-column=>1);

#This must be at the end of every Tk section
MainLoop;

sub select_tissue
{
    my $dir=$mw-> chooseDirectory(-initialdir =>'Z:\Projects\RunMSMS\M
+GF\human\ion_trap');
    $dir = encode("windows-1252", $dir);
    my @fulldir=split(/\//,$dir);#split out tissue type from full dire
+ctory
    my $tis=$fulldir[6];
    return $tis;
}

sub do_end  #
{
    my ($tissue)=@_;
    open INFO_OUT, ">>test_gui_output.txt" or die $!;
    print INFO_OUT "$tissue\n";
    exit; #close gui window
}

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In reply to Perk Tk - how to send a value from a subroutine back to the main program using Button by Anonymous Monk

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