How to test if a module is installed ?
Hi !
My perlscript uses the Image::Size module.
It works fine if it is installed, but if not I get a compilation error msg.
How can I test with perl if it is installed on my system ?
Is there something like
if ( -e Image::Size ) { use Image::Size ;}
else { print(" module not installed");}
Dennis
icq: #28395132
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RE: How to test if a module is installed ?
command line:
perl -e "use Image::Size"
if you get an error, it's missing, else it's installed.
> -Original Message-
> From: Dennis Senftleben [mailto:[EMAIL PROTECTED]]
> Sent: Friday, April 19, 2002 12:03 PM
> To: [EMAIL PROTECTED]
> Subject: How to test if a module is installed ?
>
>
> Hi !
> My perlscript uses the Image::Size module.
> It works fine if it is installed, but if not I get a
> compilation error msg.
> How can I test with perl if it is installed on my system ?
> Is there something like
> if ( -e Image::Size ) { use Image::Size ;}
> else { print(" module not installed");}
>
> Dennis
>
>
> icq: #28395132
>
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> This message was sent by Postaci Webmail. See www.trlinux.com
> for details.
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RE: How to test if a module is installed ?
Something like this should work...
if ( eval "require Image::Size" ) {
Image::Size->import();
print "The module is installed!";
}
else {
print "It's not installed!";
}
Rob
-Original Message-
From: Dennis Senftleben [mailto:[EMAIL PROTECTED]]
Sent: Friday, April 19, 2002 12:03 PM
To: [EMAIL PROTECTED]
Subject: How to test if a module is installed ?
Hi !
My perlscript uses the Image::Size module.
It works fine if it is installed, but if not I get a compilation error msg.
How can I test with perl if it is installed on my system ?
Is there something like
if ( -e Image::Size ) { use Image::Size ;}
else { print(" module not installed");}
Dennis
icq: #28395132
---
This message was sent by Postaci Webmail. See www.trlinux.com for details.
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Re: How to test if a module is installed ?
On Fri, Apr 19, 2002 at 06:02:32PM +0200, Dennis Senftleben wrote:
> Hi !
> My perlscript uses the Image::Size module.
> It works fine if it is installed, but if not I get a compilation error msg.
> How can I test with perl if it is installed on my system ?
> Is there something like
> if ( -e Image::Size ) { use Image::Size ;}
> else { print(" module not installed");}
Although two other people already have answered, I think I can add a bit
more information:
First of all: In your case, it seems as if the application should behave
as it already does: 'die' if not all requirements are fulfilled.
If, however, you want to run anyways, but with limited features, first
let's look into the documentation:
perldoc -f use
gives us:
-- snip --
use Module VERSION LIST
use Module VERSION
use Module LIST
use Module
use VERSION
Imports some semantics into the current package
from the named module, generally by aliasing cer-
tain subroutine or variable names into your pack-
age. It is exactly equivalent to
BEGIN { require Module; import Module LIST; }
except that Module must be a bareword.
-- snip --
So what you can do is this:
-- snip --
#!/usr/bin/perl
use warnings;
use strict;
BEGIN {
eval { require Data::Dumper; import Data::Dumper; };
eval { require funky_named_mod; import funky_named_mod; };
}
print Dumper({a => 1, b => 2, c => 3})
if $INC{'Data/Dumper.pm'};
print Unavailable_function()
if $INC{'funky_named_mod.pm'};
-- snip --
Now you can decide what to do at runtime. Stuff the parts that are
dependand on Module_X into a clause checking %INC for the corresponding
key 'Module_X.pm';
Search for '%INC' in
perldoc perlvar
--
If we fail, we will lose the war.
Michael Lamertz| +49 221 445420 / +49 171 6900 310
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Germany| http://www.perl-ronin.de
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