How can I get the version and location of an installed Perl module? - perl

Question

Is there a smart way to detect whether a certain Perl module has been installed in your system?
My old sutpid way is to write a Perl script in which the only thing I do is just to use the module. If nothing croaks when I run the detect script, then I know the module has been installed, although I still don't know which version and where the module has been installed .
thanks in advance.

Answer 1

Something like:
perl -MModule -e 'print "$Module::VERSION\n"' 2>/dev/null || echo "Not installed"
would give you the version of a given module, or tell you it isn't installed. Usage would look like:
perl -MXML::Parser -e 'print "$XML::Parser::VERSION\n"' 2>/dev/null || echo "Not installed"
To find the module path, you could examine #INC to find possible locations, or you could perhaps look into perlwhich. There is also pmpath from pmtools.

Answer 2

The shortest thing I know of that doesn't involve a script or shell alias:
$ perl -MFoo::Bar\ 99
Foo::Bar version 99 required--this is only version 1.234.
(or the usual message about not being in #INC if it's not installed)
For the curious, this is the same as perl -e 'use Foo::Bar 99'.

Answer 3

instmodsh
NAME
instmodsh - A shell to examine installed modules
SYNOPSIS
instmodsh
DESCRIPTION
A little interface to ExtUtils::Installed to examine installed modules, validate your packlists and even create a tarball from an installed module.
SEE ALSO
ExtUtils::Installed

Answer 4

Here's a program which does that:
#!/usr/bin/perl
# testmod - test to see if a module is available
use strict;
use warnings;
my $mod = (shift #ARGV) || die "usage: $0 module\n";
# convert module-name to path
my $file = $mod;
$file =~ s{::}{/}gsmx;
$file .= '.pm';
# Pull in the module, if it exists
eval { require $file }
or die "can't find module $mod\n";
# Get the version from the module, if defined
my $ver;
{ no strict 'refs';
$ver = ${$mod . "::VERSION"} || 'UNKNOWN';
}
# And its location
my $from = $INC{$file};
print "module $mod is version $ver loaded from $from\n";

Answer 5

Use pmvers. Like the name suggests, it shows the version of an installed module. If a module is not installed, it fails with the familiar error message: Can't locate … in #INC (#INC contains: …)
Use pmpath from the same distribution to find a module's installation path.

Answer 6

I use these bash function/Perl oneliners to find the version number and location of Perl modules:
# equivalent to perldoc -l <module>
perlwhere() {
perl -wle'eval "require $ARGV[0]" or die; ($mod = $ARGV[0]) =~ s|::|/|g; print $INC{"${mod}.pm"}' $1
}
perlversion() {
perl -M$1 -wle'print $ARGV[0]->VERSION' $1
}
: [ether ~].2$; perlwhere Test::More
/usr/lib/perl5/5.8.8/Test/More.pm
: [ether ~].2$; perlversion Test::More
0.94

Answer 7

I don't know if there is any smart way for this. But what I usually
do is to make use of '-l' or '-m' option of perldoc. For example :
%perldoc -l XML::Simple
and the output is something like below,which is the full path of module file
.../lib/XML/Simple.pm
The advantage with this approach compared to yours is that, if the module is installed
the output contains the path for module location. However when the module is not
installed
or if it doesn't has a perldoc the error message shown is "No documentation found for ...",
making it impossible to distinguish if the error is due to missing module or missing
documentation. In such scenario the -m option becomes handy since it prints entire
contents of the file along with the path.

Answer 8

The pmvers utility and the other pmtools will do what you need. Otherwise here is a one-liner to find a module version:
perl -le 'eval "require $ARGV[0]" and print $ARGV[0]->VERSION' Some::Module

Answer 9

If you're looking for a cross-platform CLI (Linux, OSX, Windows), consider my whichpm utility; e.g.:
# Locate the Data::Dumper module, and also print
# version information and core-module status.
$ whichpm -v Data::Dumper
Data::Dumper 2.145 core>=5.005 /usr/lib/perl/5.18/Data/Dumper.pm
It can also find accidental duplicates and list all installed modules.
If you happen to have Node.js / io.js installed, you can install it from the npm registry:
[sudo] npm install whichpm -g
For manual installation instructions and more, see the repo; here's a direct download link to the latest version (will stay current).