Export scalars with 'on fly' generated names 1

[1yura1]

Hi All.

I have symple hash in module (ModuleName), for example:
my %exec;
$exec{'cat'} = '/bin/cat';
$exec{'grep'} = '/bin/grep';
$exec{'host'} = '/usr/bin/host';

I want module export scalars with 'on fly' generated (from this hash) names=hash keys, and scalars values=hash values.

As the result, I need to import scalars in a script:

use ModuleName qw($cat $grep $host);

Where should be:
$cat = '/bin/cat';
$grep= '/bin/grep';
$host = '/usr/bin/host';

Is it possible in Perl?
Thanks.

 

[mikevh]

I'm not sure I understand. Do you mean this?

package ModuleName;
use strict;
use warnings;
use Exporter();
our ($VERSION, @ISA, @EXPORT, @EXPORT_OK, %EXPORT_TAGS);
@ISA = qw(Exporter);
[b]@EXPORT_OK = qw($cat $grep $host);[/b]

my %exec;
$exec{'cat'} = '/bin/cat';
$exec{'grep'} = '/bin/grep';
$exec{'host'} = '/usr/bin/host';

[b]our ($cat, $grep, $host) = @exec{qw(cat grep host)};[/b]

1;

package Someprog;
use strict;
use warnings;
[b]use ModuleName qw($cat $grep $host);[/b]

print qq(\$cat = $cat\n\$grep = $grep\n\$host = $host\n);

Output:
$cat = /bin/cat
$grep = /bin/grep
$host = /usr/bin/host

I say I'm not sure I understand as this seems to be what you're asking, but I don't see where "on the fly" figures into it. ??

 

[MikeLacey]

because the variable names might not be $cat, $grep etc

:-( don't know - an eval trick is called for obviously but I'm rubbish at those -- anyone?

Mike

"Deliver me from the bane of civilised life; teddy bear envy."

Want to get great answers to your Tek-Tips questions? Have a look at faq219-2884

 

[1yura1]

Hello,

Thanks for your replies.

The issue is that I don't know hash keys/values, theirs number (in general). The hash is stored in XML, and has to be loaded from it.

So I need dynamicly form @EXPORT_OK.
But the script will import variables as you wrote by:
use ModuleName qw($cat $grep $host);

I need the mechanizm to "translate" hash keys into scalar names, hash key value - into this scalar value, and "push" these scalars into @EXPORT_OK for exporting.

 

[mikevh]

Is there a reason why you can't just export the whole hash?

 

[1yura1]

Hello,

It is easier to work with imported scalars instead of hash ,,,
And it is interesting for me if there is the way to do such export/import.

Best Regards.

 

[chessbot]

So you're looking for the Perl equivalent of PHP's variable variables.

--Chessbot

"So it goes."
Kurt Vonnegut, Slaughterhouse Five

 

[1yura1]

Hi Chessbot.

Yes, exactly, are the same possible in Perl?

Thanks,
Yura.

 

[ishnid]

Yes, it's known as a 'symbolic reference' but it's regarded as being a *very* bad idea.

 

[MikeLacey]

ishnid makes a good point imho

Mike

"Deliver me from the bane of civilised life; teddy bear envy."

Want to get great answers to your Tek-Tips questions? Have a look at faq219-2884

 

[1yura1]

OK,
Thanks a lot.

Best Regards.
Yura.