niemeand has asked for the wisdom of the Perl Monks concerning the following question:

Hi monks. I would like to use one script on different systems but can't presume the installation of different modules.

In the scenario of a special desired but not available module, the functionality of cause should not be provide.

My problem isn't to inform the script manually by setting a flag in the preferences file of this app, if module available or not, but I don't know how to let the perlinterpreter ignore concerned code by using "require" or call a procedure to an if-condition, where the "use module" -state is inside, without getting a message like:

Can't locate Image/Magick.pm in @INC ...

Many thanks in advance,
Andreas Niemeyer

  • Comment on existence check of Module and dynamic load

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Re: existence check of Module and dynamic load
by robartes (Priest) on Feb 07, 2003 at 10:55 UTC
    Hi,

    you could simply wrap the use of your optional module in an eval block: 

    eval "use Foo;";
if ($@=~/Can't locate/) {
  print "Module Foo is not available.\n";
}

    [download]

    CU
    Robartes-

[reply]
[d/l]
Re: existence check of Module and dynamic load
by Pardus (Pilgrim) on Feb 07, 2003 at 10:53 UTC
    So basicly you want to check for module availability on run-time ? This will work: 
    eval('require Image/Magick.pm');
my $IM = $@ ? 0 : 1;

#...

if ($IM) {
    #Some Image::Magick specific code
}

    [download]

    --
    Jaap Karssenberg || Pardus (Larus)? <pardus@cpan.org>
    >>>> Zoidberg: So many memories, so many strange fluids gushing out of patients' bodies.... <<<<
[reply]
[d/l]
Re: existence check of Module and dynamic load
by niemeand (Initiate) on Feb 07, 2003 at 12:41 UTC
    Great, many thanks for help. Best regards, Andreas Niemeyer
[reply]

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