From: "Dan Muey" <[EMAIL PROTECTED]>
> Here's something I've been wondering....
>
> What kind of performance issues are there if you do a 'use' on the
> same module in the same script twice or more?
Depends.
This can be verry different for different modules.
use Module;
does two things:
1. it loads, parses and compiles a module
2. it calls it's import() function
While the first action is only been done the very first time the
module is use()d anywhere in your script, the import() will be called
each time you use the module.
Try this:
#file Foo.pm
package Foo;
sub import {
print "Import called\n";
}
1;
#file foo.pl
use Foo;
use Foo;
use Foo;
print "ENDE\n";
The import() function usualy just import some functions or variables
into the calling package in which you use()d the module, but there
are some modules that do a lot more. They usualy do take care they do
not do that twice though.
> Before you go ' Well that's stupid, why would you do that? ' let me
> explain :
>
> Script one has
>
> use CGI;
> ...
> If it does cause perfance issues is there a way to check and see if
> the module's already been 'use'd and then if it hasn't then do use ?
>
> EG if(??????) { use CGI; }
if (!exists $INC{'CGI.pm'}) {
eval "use CGI";
}
> What if you already did
>
> Use CGI params; and in the sub routine you only need say use CGI
> self_url; ? Or if you did use CGI param earlier and the sin does use
> CGI;
I'm afraid you'll have to try this and see.
Jenda
===== [EMAIL PROTECTED] === http://Jenda.Krynicky.cz =====
When it comes to wine, women and song, wizards are allowed
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