Beefy Boxes and Bandwidth Generously Provided by pair Networks
Think about Loose Coupling
 
PerlMonks  

RE: Module Usage

by Anonymous Monk
on Oct 15, 2000 at 11:17 UTC ( #36797=note: print w/replies, xml ) Need Help??


in reply to Module Usage

...because you typed 'use ThisModule;' at the top of your code is the simple answer -- since use'ing occurs at compile-time, then the statement must already occur in your code. You cannot load a module twice, if it has already been loaded with use or require. This also means that you can't have two different versions of the same module loaded at one time either.

if you are talking dynamic inclusion of module at runtime, or in response to user responses etc, then the perl idiom you are looking for is:

if ( $i_need_a_dynamically_loaded_module ) { eval "require Module"; $@ && warn $@; }

if you have a list of modules which could do the job but you don't know what the host has, then either traverse @INC manually (clumsy), or try something like:

my $loaded_mod; foreach my $mod ( qw( Module1 Module2 Module3 ) ) { warn "attempting to load '$mod'"; eval "require $mod"; next if $@; warn "'$mod' loaded successfully"; $loaded_mod = $mod; last; } $loaded_mod or die "Couldn't load anything useful..."; ...

dirty

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://36797]
help
Chatterbox?
[Discipulus]: i need some converter to have directly an OVF format directly: at the moment i'm trying with vmware converter standalone
[Lady_Aleena]: I don't know what to tell you. I can barely get my Linux machine to do things I want.
[Discipulus]: if DE or WM means desktop env and win manager.. no, not an option
[Lady_Aleena]: That's what they mean, at least to me. 8)
[Discipulus]: in the first attempt i failed, with an not usable v-machine.. ;=)
[Discipulus]: but then discovered a registry trick to do before the physical2virtual migration
[Lady_Aleena]: Sounds like a headache.
[Discipulus]: a bit shaggy.. every atttempt is ~4hours to virtualize and 1-2hours to kick the big file to boot..

How do I use this? | Other CB clients
Other Users?
Others meditating upon the Monastery: (5)
As of 2017-05-22 18:45 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?