With pip you are able to create a requirements file to specify which libraries to install. Is there an equivalent for perl modules using CPAN?
I came across ExtUtils::MakeMaker, but this seems like the make file is for each module specifically.
I guess to try and give a better idea of what I am asking is if there is a way to do something like
cpan install -r requirements.txt
and then specify which modules to install in that requirements file.
Thanks in advance!
When you install modules from CPAN, each module specifies its dependencies in the Makefile.PL (or Build.PL) and the CPAN shell will resolve those dependencies recursively when installing.
If you want to specify dependencies for an application (rather than a CPAN module), you can create a file called cpanfile in this format:
requires 'JSON';
requires 'Template';
requires 'DateTime';
requires 'DBIx::Class';
Then you can install those dependencies with one command:
cpanm --installdeps .
The cpanm command comes from the App::cpanminus distribution and is an alternative tool for installing modules from CPAN.
See the cpanfile docs for more information.
I think Carton is what you're looking for.
To start using Carton, install it. Then create a cpanfile with your dependencies:
require 'Test::Most';
require 'Math::BaseConvert';
With this file in place, run
carton install
This will install those modules, if necessary, and write a file called cpanfile.snapshot with dependency information.
Also see: Brief Notes on Managing Perl Dependencies with Carton
PS: Check out Stratopan.
Related
While loading necessities into my crouton, apt-get recommended that I install libtemplate-perl. This seemed a jolly idea, and I obeyed.
Reading this answer, I see a fellow traveler install Plack and Starman via CPAN, but then use apt-get to install Dancer.
Minutes before reading said answer, I had installed Dancer via CPAN. And it had worked. It had worked real good!
What happens differently when I install a CPAN package via a non-CPAN package manager? Are there pitfalls I need to be wary of because my libtemplate-perl came from apt-get, or my Dancer came from CPAN?
On Debian or Debian based distros like Ubuntu, CPAN (/usr/bin/cpan utility) installs modules into /usr/local/lib/ by default. And Debian packages keep their files in /usr/share/perl5/ and /usr/lib/perl5/.
It's a better way to choose dh-make-perl tool to package any CPAN distribution not available in your apt repositories, to avoid making mess (serious risk of conflict between apt and CPAN):
dh-make-perl --build --cpan Some::Module
dpkg -i some-module*.deb
Also check out about local::lib and perlbrew.
A lot of tutorials, Stack Overflow answers, walk throughs, etc. will not want to assume that you know how to use /usr/bin/cpan and will instead suggest that you use your system's package manager, which you are more likely to be familiar with.
This is especially true if you are using a tool written in a particular language, but you don't know that language. For example many people wouldn't care whether crouton is written in Perl, Python or Lisp, they just want a tool they can use. Your average Debian or Ubuntu user is more likely to be familiar with apt-get than with cpan.
If you are looking to program in Perl I recommend installing things by cpan, using perlbrew and/or local::lib. If you are just looking to install a tool you can use, I would recommend using apt-get.
Additionally apt-get has the advantage that non-Perl dependencies will be installed automatically. For example the CPAN module XML::LibXML requires that the libxml2 headers are available on the system; the CPAN distribution has no way of stating that as a dependency, and will simply fail on install if it can find the headers to link against. The Debian package can actually specify that libxml2 is a dependency, and will install the dependency automatically for you.
Despite that if you are looking to use XML::LibXML as a Perl programmer, I would recommend installing it with cpan and installing the libxml2 package via apt-get. Having all your Perl modules installed in the same place - again, via perlbrew or local::lib - will help you keep your sanity in the future. CPAN is preferable to apt-get in this case because not all distributions have been packaged for Debian, and so you get a lot more options if you use CPAN directly.
In summary: TIMTOWTDI ;-)
Another difference to mention that I don't see in other answers, is that if you use CPAN to install a module then the module version you get will be set, until you decide to upgrade that module. Whereas, if you use apt and a later version appears in Debian at some point in the future, then apt-get upgrade will update it.
Maybe you want that, maybe you don't. It's neither necessarily an advantage, nor a disadvantage. Simply a difference to be noted.
The good things about apt-get are
that you can uninstall the packages afterwards should you need to
if you are maintaining any number of servers it is quicker to use apt-get as there is no building required
there are definite versions of packages which are tested for compatibility
The downsides are
not necessarily the latest version of packages
not all packages are available
apt-get installs are generally easier and better than cpan because of dependencies alone.
If you are so lucky as to need SOAP::Lite, for example, it is many dozens of dependencies, and a one-line "apt-get install libsoap-lite-perl".
It is sometimes not clear how Perl CPAN names map to their repository package names, but "apt-cache search " is your friend.
Another approach, that can be used for any distro in HOME install as simple user:
Pros
avoid conflicts
up to date version of perl and modules
when you reinstall, you keep your home/perl as-si
you can upgrade all installed modules with $ cpan -r
Cons
you need to upgrade Perl manually
How to
Edit ~/.bashrc or such, and add:
export PERL5LIB=~/localperl/lib/
export PATH=~/localperl/bin:$PATH
Then
source ~/.bashrc
Install latest Perl5 from sources: https://www.cpan.org/src/README.html
Now, you have an isolate Perl installation in your home.
Enjoy the power to install any libs via:
$ cpan -i Whatever::Module
I'm taking a look into Perl as a total beginner. I want to try some CPAN modules.
When I run an install command on my Osx console, CPAN asks for a configuration with the following statement :
To install modules, you need to configure a local Perl library
directory or escalate your privileges. CPAN can help you by
bootstrapping the local::lib module or by configuring itself to use
'sudo' (if available). You may also resolve this problem manually if
you need to customize your setup.
What approach do you want? (Choose 'local::lib', 'sudo' or 'manual')
What is the difference between local::lib and sudo options ?
If I understand it well, it installs some modules locally on my computer. But I don't see any difference between the two config above.
If you use sudo, CPAN will use root to install the libraries in a central location where all users on the machine can access the files without any special configuration. If you use 'local::lib', it will create a library in your home directory and install the modules such that only perl programs that have been configured to look for modules in your home directory will find the modules.
Perl uses the special variable #INC to search for module paths. So you can install modules anywhere as long as you set #INC properly before you use them. This article explains the basics.
http://www.symkat.com/find-a-perl-modules-path
You can do all kinds of fun stuff with #INC; one of my favorite hacks it to put a function pointer in there and use custom perl code to lookup modules.
Good question. When you use local::lib, you can install Modules via CPAN User specific in an given directory. Assume you choose sudo as approach, you install Modules global.
Its like installing Node.js via npm. When you install a module with npm install -g <Modul>, its global installed and you can use it everywhere. But withouth that -g flag, its just available inside your current directory.
Its about the same here, except that you choose the default way of installing CPAN Modules.
I have been writing Perl scripts for my work and the machine that I have been given to work on makes installing Perl modules difficult:
We cannot have gcc on my machine for security reasons, so I cannot use CPAN to install modules, for most modules.
I do not have access to the root account.
Usually, when I want to install a module, I put in a request and I have to wait a day or two before it gets installed. I know that nobody would have a problem with me installing them myself, so to save everyone's time and my sanity I would like to install them myself. It's just an issue of how to best do that. I have talked to various people and they said to use an RPM to install them (to get around not having gcc). However, when trying to install modules from RPMs, it does not handle the dependencies so I would manually need to handle the dependencies, which could take a while.
How can I best install Perl modules with these limitations?
On a similar machine with a similarly built Perl, install the module(s) using
mkdir ~/foo
cpan
o conf makepl_arg 'PREFIX=~/foo LIB=~/foo/lib/perl5'
o conf mbuildpl_arg '--prefix ~/foo --lib ~/foo/lib/perl5'
install Some::Module
As long as you don't do o conf commit, the configuration change will be temporary, so don't do that.
Copy ~/foo over, and set env var PERL5LIB to include the LIB directory. You can merge a newer ~/foo into an older one to add new modules.
This won't install any non-Perl libraries on which the modules depend.
See also How do I keep my own module/library directory? in section 8 of the Perl FAQ.
When you build modules, tell Perl where to install the modules.
For Makefile.PL-based distributions, use the INSTALL_BASE option when generating Makefiles:
perl Makefile.PL INSTALL_BASE=/mydir/perl
For Build.PL-based distributions, use the --install_base option:
perl Build.PL --install_base /mydir/perl
INSTALL_BASE tells these tools to put your modules into /mydir/perl/lib/perl5. See How do I add a directory to my include path (#INC) at runtime? for details on how to run your newly installed modules.
There is one caveat with INSTALL_BASE, though, since it acts differently from the PREFIX and LIB settings that older versions of ExtUtils::MakeMaker advocated. INSTALL_BASE does not support installing modules for multiple versions of Perl or different architectures under the same directory. You should consider whether you really want that and, if you do, use the older PREFIX and LIB settings. See the ExtUtils::Makemaker documentation for more details.
I want to send emails using gmail's smtp servers and perl. I am trying to install Email::Send::Gmail, but it is not clear to me what are the steps to install it. It seems that it depends on other modules that I do not have installed.
This is partially dependent on which distribution of Perl you're using.
ActivePerl includes a utility called PPM (Perl Package Manager) for installing modules. It handles dependency resolution automatically. PPM is particularly nice for installing XS modules on Windows where a compiler isn't typically available. The downside to PPM is that it some CPAN modules aren't available (probably because they fail ActiveState's automated build process). You can run PPM from either the start menu or by typing ppm at a command prompt.
A more general option is to use the interactive CPAN shell. Note that you must have a compiler to install XS modules using this method. You can access the cpan shell by typing cpan at a command prompt.
The brute-force approach of last resort is to download tarballs from CPAN and manually install them one at a time. When an install aborts due to unsatisfied dependencies download and install them then go back to the first module and try again.
Type:
cpan Email::Send::Gmail
… at the command prompt.
It's probably a good idea to set up local::lib first.
Or see the Perl Foundation Wiki on installing CPAN modules or the same but without root access.
Or see the CPAN guide to installing modules.
If you are using ActivePerl, try the PPM (Perl Package Manager) tool that comes with ActivePerl first. When you tell it to install a module, it should handle all of the dependencies for you.
Note the dependency tree for Email::Send::Gmail. Some of those modules require additional installation of third party software, most notably OpenSSL, which cpan won't do for you.
You can probably install it with:
perl -MCPAN -e shell
install Email-Send-Gmail
Hope it helps,
/Klaus
If you can, CPAN. (ha! It rhymes ... what a crime. Oops, did it again! When will this end... :p) It's essentially the way to install modules for your system. It automatically detects dependencies, downloads, installs, and tests them all for you, and backs out if ever a build or test fails. It's a fantastic and reliable way of installing modules. This works great if you're using essentially any Perl distribution besides ActiveState's distribution, including Strawberry Perl. Generally, this is done with
cpan Module::Name
or, in an interactive mode,
$ cpan
cpan > install Module::Name
If you're using ActiveState Perl, then you probably want to use ActiveState's PPM (Perl Package Manager). It's similar to CPAN, except everything comes prebuilt for ActiveState Perl. ActiveState has a document on how to use their Perl Package Manager on their website, including a graphical example.
If the easy options fail, you are not out of luck. There's some more complex, but manual methods you can do to still install the module.
Most modules that you can download will have within them a bit of metadata in a .yaml file; this will help you figure out whether or not you have all your dependencies. CPAN and PPM automatically resolve and install all your dependencies, but doing it manually will not, leaving that task up to you.
Assuming you have all your dependencies, and you need to install it manually, look for one of two files: Makefile.PL or Build.PL. If you have a Makefile.PL, cd to the directory you extraced the module within a command prompt, and type:
perl Makefile.PL
make
make test
make install
You will need a 'make' program on your system. If it's ActiveState Perl, you may need to install the module manually (see a paragraph or two down.)
If it happens to have a Build.PL, then you need to do a slightly different set of steps:
perl Build.PL
Build
Build test
Build install
(Of course, you may want to consider not installing if make/Build test fails, but that's up to you.)
As a final alternative, if your module has no xs files (ie, code that needs to be compiled on install), and all dependencies are met, you can simply move the files in the lib folder to your perl installation's site\lib folder. If you're interested in just using it for one project, you can add a PERL5LIB environmental variable, pointing to a new, custom library directory (eg, /my/project/lib) and then before running your tool, make sure the environment is set up.
As a followup, see PerlFaq8 - How do I install a module from CPAN.
Also, see PerlFaq8 - How do I keep my own module/library directory?.
Mixing installation methods is asking for heartache and headaches you don't need.
Don't use CPAN with Active Perl. Use PPM.*
PPM download sources can be found at Randy Kobes' site.
If you can't find a PPM of a module you need, you can build your own PPMs easily with Mr. Kobes make_ppm.
You can download a distribution and simply run make_ppm to build a PPM, but I prefer to do the a more "normal" build process:
perl Makefile.PL
make
make test
make_ppm
*If you install your files outside of c:/perl/site/* then it's OK to use CPAN. Just don't co-mingle CPAN shell modules with PPM modules.
Is it possible?
If you download the source code, and read the README file. This will probably tell you you should do
perl Makefile.PL
make
make test
make install
or
perl Build.PL
./Build
./Build test
./Build install
If you download the source code, it will generally have a Makefile.PL. You run "perl Makefile.PL; make; make test; make install" and it will build and install for you.
Obviously if you're not using CPAN.pm, you're going to have to deal with dependencies yourself.
Also, if the reason you can't use CPAN.pm is that you don't have permission to install into /usr/lib/perl, you can force CPAN.pm to install locally, but I forget how.
If you are on a Linux box, a very large portion of the packages can usually be obtained using the built in package manager. For instance, on an Ubuntu system, if you want to install the PostgreSQL Perl module you'd simple do:
sudo apt-get install libpg-perl
You can see a list of the modules for Ubuntu here: http://packages.ubuntu.com/hardy/perl/
I find I can often guess at the names myself. Not sure if this helps at all, but for myself I often find this easier to use than CPAN as it does a lot better at resolving dependencies.
See here: How to install perl modules using CPAN without root
I have just set this up on a server without root access and CPAN does everything automatically.
But if you really wanna install a module without CPAN and you don't have root (assuming this since you don't wanna use CPAN), you can do it as follows
perl Makefile.PL PREFIX=$HOME
make
make install
You're gonna have to hunt down dependencies yourself so it's better to use CPAN.
If the problem is no root access, I would recommend looking at local::lib and also this webpage for CPAN.pm and non-root installation.
But to answer the question as asked, CPAN or CPANPLUS are helpful, but they aren't required. You can always do it the old-fashioned way as Leon says - though usually, it's easier not to.
If you are using Red Hat (Fedora, CentOS), you should use RPM for Perl dependencies wherever possible. Perl packages are almost always named perl-Module-Name, e.g. perl-DBI, perl-Spreadsheet-WriteExcel, etc.
On Ubuntu the naming scheme is libmodule-name-perl.
If the .pm file is pure Perl and doesn't need to be compiled you can just put it in your application's lib folder and use it as normal.
We can install all perl modules both from and even with your terminal in ubuntu. If you are using a ubuntu server then execute the following command ,
'sudo apt-get install "perl_module"'
The modules which you want just give the name in "perl_module" means If you want to install Apache2::Cookie it will be in "libapreq2" so you have to give like,
"sudo apt-get install libapreq2"
I, as others have would highly suggest using CPAN.pm. It is a breeze to use and can resolve any dependencies associated with the module you need automatically.
On the other hand, I would suggest that you read the perlmodinstall document over at perldoc as it gives details on other os' as well.
Regards,
Jeff
If you're asking this because you're having problems with CPAN... you're probably running out of RAM that's why you can't use CPAN.
Maybe you don't have a swap file. Try this:
$ sudo su
# dd if=/dev/zero of=/swap bs=1M count=1k # create a 1GB file
# mkswap /swap
# swapon /swap
Otherwise... stop some services.
$ sudo service mysql stop
$ sudo service nginx stop
...And try again
$ cpan install CPAN
$ cpan install MIME::Lite::TT::HTML