topic Re: Perl question in Operating System - Linux

Perl question

Alexander Chuzhoy — Fri, 07 May 2004 01:19:20 GMT

I want to be able to work with variable's value that's another variable's name.For example:

%all=("\$a"=>$buta,"\$b"=>$butb);
for $temp(keys %all) {
if ($all{$temp} eq 1) {
$temp->destroy;
last;
}
}
How can I achieve this?

Re: Perl question

Stuart Browne — Fri, 07 May 2004 01:37:06 GMT

Umm, simpler than that.

#!/usr/bin/perl -w
use strict;
my $a = "test";
my $b = "test2";

my $adata = 'one';
my $bdata = 'two';

my %hash = (
$a => $adata,
$b => $bdata
);

for my $key (keys %hash) {
printf( "Got here with %s and %s\n", $key, $hash{$key} );
}

Re: Perl question

Alexander Chuzhoy — Fri, 07 May 2004 01:46:07 GMT

hey ,Stuart.Thanks for your reply.
My problem is kinda more complex.
$a specifies a button.

$a = $mw -> Checkbutton ('-indicator'=>off, '-activebackground'=>green, '-border'=>15, '-text'=>green, -command=>\&action, '-variable'=>\$buta)-> place ( -x=>10, -y=>10, -height=>40, -width=>40);

I wish to destroy this button if someone clicks on it.Of course it's simple if there's only one button.
But I wish to destroy a specific button if someone clicks on it....

Re: Perl question

Mark Grant — Fri, 07 May 2004 01:54:55 GMT

Why don't you just pass the reference to the button to the "action" function and delete the button there?

Re: Perl question

Alexander Chuzhoy — Fri, 07 May 2004 02:01:38 GMT

Hey,Mark!
Because this way I'll have to define different function for each button.
I'll do that if there's no choice, but I wish to make the program as smaller as possible.
Ego issues :)

Re: Perl question

Gregory Fruth — Fri, 07 May 2004 14:44:40 GMT

Try wrapping the destroy call in an eval:

eval "$temp->destroy";

Also, the "if ($all{$temp} eq 1)" looks a
bit fishy; perhaps it should be
"if ($app{$temp})".

HTH

Re: Perl question

Mark Grant — Sat, 08 May 2004 04:12:13 GMT

You won't need a seperate function for each button. define the command as

[ \&action,$a ] for the first button
[ \&action,$b ] for the second button and so on.

In you action function, destroy $_[0]

Re: Perl question

Stuart Browne — Sat, 08 May 2004 19:11:52 GMT

Can't you use ${$temp}->destroy ?

I've not done much OO in perl.

Re: Perl question

Alexander Chuzhoy — Sun, 09 May 2004 07:45:27 GMT

Hi,Gregory!
Thanks for the eval tip.
Regarding your second advise:
Also, the "if ($all{$temp} eq 1)" looks a
bit fishy; perhaps it should be
"if ($app{$temp})".

I specifically do
"if ($all{$temp} eq 1)"
because there's also
"if ($all{$temp} eq 2)"

so:
"if ($app{$temp})" won't be good enough

Re: Perl question

Alexander Chuzhoy — Sun, 09 May 2004 07:53:58 GMT

Stuart, in this particular case -I can't.
I probably miss something...

Re: Perl question

Alexander Chuzhoy — Sun, 09 May 2004 08:41:35 GMT

Hey,Mark.Your last advice seems nice-although I can't make it work.

Here's a sample:
$a=$mw->Checkbutton('-indicator'=>off,'-activebackground'=>green,'-border'=>15,'-text'=>green,-command=>sub {&action,$a},'-variable'=>\$buta)->place(-x=>10,-y=>10,-height=>40,-width=>40);

sub action {
destroy $_[0];
}
I guess the sintax isn't correct.But what exactly?

Re: Perl question

Mark Grant — Mon, 10 May 2004 05:14:07 GMT

I don't think you'll get away with an anonymous function in this case. You'll need an "action" function and pass parameters to it as an array as in "-command => [ \&action,$a ]"

Then you need your destroy in the "action" subroutine.

Re: Perl question

Sheldon Plankton — Thu, 03 Jun 2004 16:45:13 GMT

You could always ask the perlmonks.
http://www.perlmonks.org