I get this error:
Can't locate Foo.pm in #INC
Is there an easier way to install it than downloading, untarring, making, etc?
On Unix:
usually you start cpan in your shell:
$ cpan
and type
install Chocolate::Belgian
or in short form:
cpan Chocolate::Belgian
On Windows:
If you're using ActivePerl on Windows, the PPM (Perl Package Manager) has much of the same functionality as CPAN.pm.
Example:
$ ppm
ppm> search net-smtp
ppm> install Net-SMTP-Multipart
see How do I install Perl modules? in the CPAN FAQ
Many distributions ship a lot of perl modules as packages.
Debian/Ubuntu: apt-cache search 'perl$'
Arch Linux: pacman -Ss '^perl-'
Gentoo: category dev-perl
You should always prefer them as you benefit from automatic (security) updates and the ease of removal. This can be pretty tricky with the cpan tool itself.
For Gentoo there's a nice tool called g-cpan which builds/installs the module from CPAN and creates a Gentoo package (ebuild) for you.
Try App::cpanminus:
# cpanm Chocolate::Belgian
It's great for just getting stuff installed. It provides none of the more complex functionality of CPAN or CPANPLUS, so it's easy to use, provided you know which module you want to install. If you haven't already got cpanminus, just type:
# cpan App::cpanminus
to install it.
It is also possible to install it without using cpan at all. The basic bootstrap procedure is,
curl -L http://cpanmin.us | perl - --sudo App::cpanminus
For more information go to the App::cpanminus page and look at the section on installation.
I note some folks suggesting one run cpan under sudo. That used to be necessary to install into the system directory, but modern versions of the CPAN shell allow you to configure it to use sudo just for installing. This is much safer, since it means that tests don't run as root.
If you have an old CPAN shell, simply install the new cpan ("install CPAN") and when you reload the shell, it should prompt you to configure these new directives.
Nowadays, when I'm on a system with an old CPAN, the first thing I do is update the shell and set it up to do this so I can do most of my cpan work as a normal user.
Also, I'd strongly suggest that Windows users investigate strawberry Perl. This is a version of Perl that comes packaged with a pre-configured CPAN shell as well as a compiler. It also includes some hard-to-compile Perl modules with their external C library dependencies, notably XML::Parser. This means that you can do the same thing as every other Perl user when it comes to installing modules, and things tend to "just work" a lot more often.
If you're on Ubuntu and you want to install the pre-packaged perl module (for example, geo::ipfree) try this:
$ apt-cache search perl geo::ipfree
libgeo-ipfree-perl - A look up country of ip address Perl module
$ sudo apt-get install libgeo-ipfree-perl
A couple of people mentioned the cpan utility, but it's more than just starting a shell. Just give it the modules that you want to install and let it do it's work.
$prompt> cpan Foo::Bar
If you don't give it any arguments it starts the CPAN.pm shell. This works on Unix, Mac, and should be just fine on Windows (especially Strawberry Perl).
There are several other things that you can do with the cpan tool as well. Here's a summary of the current features (which might be newer than the one that comes with CPAN.pm and perl):
-a
Creates the CPAN.pm autobundle with CPAN::Shell->autobundle.
-A module [ module ... ]
Shows the primary maintainers for the specified modules
-C module [ module ... ]
Show the Changes files for the specified modules
-D module [ module ... ]
Show the module details. This prints one line for each out-of-date module (meaning,
modules locally installed but have newer versions on CPAN). Each line has three columns:
module name, local version, and CPAN version.
-L author [ author ... ]
List the modules by the specified authors.
-h
Prints a help message.
-O
Show the out-of-date modules.
-r
Recompiles dynamically loaded modules with CPAN::Shell->recompile.
-v
Print the script version and CPAN.pm version.
sudo perl -MCPAN -e 'install Foo'
Also see Yes, even you can use CPAN. It shows how you can use CPAN without having root or sudo access.
Otto made a good suggestion. This works for Debian too, as well as any other Debian derivative. The missing piece is what to do when apt-cache search doesn't find something.
$ sudo apt-get install dh-make-perl build-essential apt-file
$ sudo apt-file update
Then whenever you have a random module you wish to install:
$ cd ~/some/path
$ dh-make-perl --build --cpan Some::Random::Module
$ sudo dpkg -i libsome-random-module-perl-0.01-1_i386.deb
This will give you a deb package that you can install to get Some::Random::Module. One of the big benefits here is man pages and sample scripts in addition to the module itself will be placed in your distro's location of choice. If the distro ever comes out with an official package for a newer version of Some::Random::Module, it will automatically be installed when you apt-get upgrade.
Already answered and accepted answer - but anyway:
IMHO the easiest way installing CPAN modules (on unix like systems, and have no idea about the wondows) is:
curl -L http://cpanmin.us | perl - --sudo App::cpanminus
The above is installing the "zero configuration CPAN modules installer" called cpanm. (Can take several minutes to install - don't break the process)
and after - simply:
cpanm Foo
cpanm Module::One
cpanm Another::Module
Many times it does happen that cpan install command fails with the message like
"make test had returned bad status, won't install without force"
In that case following is the way to install the module:
perl -MCPAN -e "CPAN::Shell->force(qw(install Foo::Bar));"
Lots of recommendation for CPAN.pm, which is great, but if you're using Perl 5.10 then you've also got access to CPANPLUS.pm which is like CPAN.pm but better.
And, of course, it's available on CPAN for people still using older versions of Perl. Why not try:
$ cpan CPANPLUS
Use cpan command as cpan Modulename
$ cpan HTML::Parser
To install dependencies automatically follow the below
$ perl -MCPAN -e shell
cpan[1]> o conf prerequisites_policy follow
cpan[2]> o conf commit
exit
I prefer App::cpanminus, it installs dependencies automatically. Just do
$ cpanm HTML::Parser
On ubuntu most perl modules are already packaged, so installing is much faster than most other systems which have to compile.
To install Foo::Bar at a commmand prompt for example usually you just do:
sudo apt-get install libfoo-bar-perl
Sadly not all modules follow that naming convention.
On Fedora Linux or Enterprise Linux, yum also tracks perl library dependencies. So, if the perl module is available, and some rpm package exports that dependency, it will install the right package for you.
yum install 'perl(Chocolate::Belgian)'
(most likely perl-Chocolate-Belgian package, or even ChocolateFactory package)
Even it should work:
cpan -i module_name
2 ways that I know of :
USING PPM :
With Windows (ActivePerl) I've used ppm
from the command line type ppm. At the ppm prompt ...
ppm> install foo
or
ppm> search foo
to get a list of foo modules available. Type help for all the commands
USING CPAN :
you can also use CPAN like this (*nix systems) :
perl -MCPAN -e 'shell'
gets you a prompt
cpan>
at the prompt ...
cpan> install foo (again to install the foo module)
type h to get a list of commands for cpan
On Fedora you can use
# yum install foo
as long as Fedora has an existing package for the module.
Easiest way for me is this:
PERL_MM_USE_DEFAULT=1 perl -MCPAN -e 'install DateTime::TimeZone'
a) automatic recursive dependency detection/resolving/installing
b) it's a shell onliner, good for setup-scripts
If you want to put the new module into a custom location that your cpan shell isn't configured to use, then perhaps, the following will be handy.
#wget <URL to the module.tgz>
##unpack
perl Build.PL
./Build destdir=$HOME install_base=$HOME
./Build destdir=$HOME install_base=$HOME install
Sometimes you can use the yum search foo to search the relative perl module, then use yum install xxx to install.
Secure solution
Many answers mention the use of the cpan utility (which uses CPAN.pm) without a word on security. By default, CPAN 2.27 and earlier configures urllist to use a http URL (namely, http://www.cpan.org/), which allows MITM attacks, thus is insecure. This is what is used to download the CHECKSUMS files, so that it needs to be changed to a secure URL (e.g. https://www.cpan.org/).
So, after running cpan and accepting the default configuration, you need to modify the generated MyConfig.pm file (the full path is output) in the following way. Replace
'urllist' => [q[http://www.cpan.org/]],
by
'urllist' => [q[https://www.cpan.org/]],
Note: https is not sufficient; you also need a web site you can trust. So, be careful if you want to choose some arbitrary mirror.
Then you can use cpan in the usual way.
My bug report on rt.cpan.org about the insecure URL.
Simply executing cpan Foo::Bar on shell would serve the purpose.
Seems like you've already got your answer but I figured I'd chime in. This is what I do in some scripts on an Ubuntu (or debian server)
#!/usr/bin/perl
use warnings;
use strict;
#I've gotten into the habit of setting this on all my scripts, prevents weird path issues if the script is not being run by root
$ENV{'PATH'} = '/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin';
#Fill this with the perl modules required for your project
my #perl = qw(LWP::Simple XML::LibXML MIME::Lite DBI DateTime Config::Tiny Proc::ProcessTable);
chomp(my $curl = `which curl`);
if(!$curl){ system('apt-get install curl -y > /dev/null'); }
chomp(my $cpanm = system('/bin/bash', '-c', 'which cpanm &>/dev/null'));
#installs cpanm if missing
if($cpanm){ system('curl -s -L http://cpanmin.us | perl - --sudo App::cpanminus'); }
#loops through required modules and installs them if missing
foreach my $x (#perl){
eval "use $x";
if($#){
system("cpanm $x");
eval "use $x";
}
}
This works well for me, maybe there is something here you can use.
On Windows with the ActiveState distribution of Perl, use the ppm command.
I'd like to install programs with conda in one particular conda environment and to be able to use the associated commands from all conda environments.
My goal is to allow students to install Mercurial (plus few Mercurial extensions and related utilities like Meld and TortoiseHg) on any platforms (especially Windows) with one simple command (or few simple commands), and of course without compilation.
Of course the hg command should be available in the terminal from any conda environments (anaconda prompt on Windows). The Mercurial packages cannot be installed in the base environment because Mercurial still works better in Python 2.7 (anyway, it wouldn't be clean).
Now Mercurial and the extensions we need can be installed on all platforms with something like:
conda create -n py27_mercurial -c conda-forge python=2.7 mercurial dulwich ipaddress
conda activate py27_mercurial
pip install hg-evolve hg-git
Working a bit with conda-forge and a conda meta-package, it won't be difficult to do that with one very simple command. Moreover, it should not be difficult to create conda packages for Meld and TortoiseHg.
From this stage, the hg command is available when the environment is activated (and it is very simple to install other Mercurial extensions). To make it available from other environment (and in the base environment), one need to append the path of the directory containing hg to the environment variable PATH or on Unix to create a symbolic link (I don't know Windows enough to know if something similar would work). Both solutions are not straightforward and the commands are not platform independent.
I didn't find a command to do something like this in conda but sometimes conda experts are able to do impressive things! What would be an elegant solution to this issue?
It would also be nice to create icons somewhere (in the Anaconda launcher?) for the graphical applications (Meld and TortoiseHg). Is it possible?
Edit: Conda applications
I discovered that there is a way to specify in the meta.yaml file that a package is an application: https://docs.conda.io/projects/conda-build/en/latest/resources/define-metadata.html#app-section
It may help to solve the issue.
Edit after a first answer based on a bash function:
Of course, I'm looking for a solution involving very small work (and understanding) for the users and with cross-platform commands.
Note that for Linux and Bash, one can just do:
CONDA_APP_DIR=$HOME/.local/bin/bin-conda-app/
mkdir -p $CONDA_APP_DIR
echo -e "\nexport PATH=\$PATH:$CONDA_APP_DIR\n" >> ~/.bashrc
ln -s $(which hg) $CONDA_APP_DIR/hg
No need to activate/deactivate the environment each time hg is used...
Of course, such solutions dependent of the system and the shell are not satisfactory. It should be possible to do such things with cross-platform conda-like commands (see https://github.com/conda/conda/issues/8556), something like
conda config --add channels conda-forge
conda install conda-app
conda-app install mercurial
Now, I just have to implement conda-app 🙂
One can always create a shell function/alias and shove it in their shell's runtime configuration file. For example, for your use case, I'd add the following in my ~/.bashrc:
hg() {
(conda activate py27_mercurial
command hg "$#"
_hg_exit_code=$?
conda deactivate
exit $_hg_exit_code)
}
Then, regardless of which environment you are in, you always run hg from the environment it was installed in. To make sure that this function is loaded for you shell in a new session, one can always take a look at the output for: type -a hg
I do this one-time-setup for all the tools (some are custom compiled) and have an alias/shell function for each. This way I can happily switch b/w environments without having to worry much.
The solution https://stackoverflow.com/a/55900964/1779806 is buggy for scripts using command hg ... and too inefficient for this case (installation of a command-line application). See https://github.com/conda/conda/issues/8556#issuecomment-488703716
I created a tiny Python package conda-app (https://pypi.org/project/conda-app/) to improve this situation.
This should now works on Unix systems (with Bash and Fish):
conda activate base
conda config --add channels conda-forge
pip install conda-app
conda-app install mercurial
It should not be difficult to improve conda-app to also support Windows.
For the time being, Windows users can install Mercurial and important extensions by installing TortoiseHG.