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

Hi all,

I'm writing an installation script that needs to check if a few modules are installed. I'm not sure of the best way to go about this and would really appreciate a pointer on how to go about it.

many thanks

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Re: script to check modules exist...
by Anonymous Monk on Apr 30, 2011 at 11:50 UTC
    That is called a Makefile.PL, see Module::Install - Standalone, extensible Perl module installer
[reply]
Re: script to check modules exist...
by anonymized user 468275 (Curate) on May 02, 2011 at 14:31 UTC 
    use Data::Dumper;

my %g_modules;

Traverse( $_ ) for ( @INC );

print Dumper \%g_modules;

sub Traverse {
        my $dir = shift;
        opendir my $dh, $dir or die "$!: $dir\n";
        for my $file ( grep !/^\./, readdir $dh ) {
                my $path = "$dir/$file";
                if ( -d $path ) {
                        Traverse ( $path );
                }
                elsif ( $file =~ /\.pm$/ ) {
                        $g_modules{ $file } = 1;
                }
        }
        closedir $dh;
}

    [download]

    One world, one people

[reply]
[d/l]
      The results of your code are misleading because it tells me I only have one file named "Base.pm". 
                'Base.pm' => 1,

      [download]
      However, I have 22 installed files named "Base.pm" 
      Chart/Base.pm
DBD/Gofer/Policy/Base.pm
DBD/Gofer/Transport/Base.pm
DBI/Gofer/Serializer/Base.pm
DBI/Gofer/Transport/Base.pm
Date/Manip/Base.pm
DateTime/Locale/Base.pm
Exception/Class/Base.pm
ExtUtils/CBuilder/Base.pm
ExtUtils/Constant/Base.pm
IO/Compress/Base.pm
IO/Uncompress/Base.pm
Log/Dispatch/Base.pm
Module/Build/Base.pm
Net/DNS/Resolver/Base.pm
TAP/Base.pm
TAP/Formatter/Base.pm
URI/file/Base.pm
XML/SAX/Base.pm
YAML/Base.pm
YAML/Dumper/Base.pm
YAML/Loader/Base.pm

      [download]
      See Find installed Perl modules matching a regular expression
[reply]
[d/l]
[select]
        It is of course possible to store the full path as a hash key instead. But it is not easy to specify where the first part of the namespace begins from that, although a site-specific solution should be possible.

        One world, one people

[reply]
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