I want a perl script that will install all the cpan modules automatically when running the perl script.Can you help this?
The CPAN client is just a Perl module which is wrapped by the command line tool. You therefore directly invoke it from a Perl script.
However, you may require system administrator priveleges to install new modules. One way to circumvent that is to use local::lib, or to ask the user for the necessary privileges. On Unixes, you could refuse to run your script if not run as root. However, that opens up many security issues and should be avoided if possible.
A fairly sane solution would be to require your users to install the cpanm client, and specify your dependencies in a cpanfile. Your users then just have to do cpanm --installdeps /dir/of/your/script.
But if we are already going through all that trouble, you might as well make a proper CPAN distribution. You don't have to upload it to CPAN, but you can distribute the tarball, and have your users install that. This has many advantages: Mature toolchains, automated testing, and wonderful helpers like Dist::Zilla that make creating a distribution a breeze.
Use CPAN::Shell, from the docs:
CPAN::Shell->install("Acme::Meta");
Related
I am creating a custom module to be placed in the directory /usr/local/cpanel/Cpanel. My perl module requires SOAP::Lite. Since the scripts placed in the directory /usr/local/cpanel/Cpanel are run under cpanel's internal perl version 5.6.2, does on install the SOAP::Lite module?
Trying to build the module with cpanel's build tool fails as another perl module is require to build the source module for soap::lite from cpan.
Perl modules are usually installed using the cpan program that comes with Perl. This checks all the dependencies for you and installs everything you need. This is what you should do.
If you don't have the ability to access and run this program, then you may not have permission to install modules at all. Possibly you could get whoever is running your system to do it for you (also ask them to upgrade your nearly 9 year old version of Perl while they are at it!).
Beyond that, there are not many options. You could try building the required modules on another, similar system and copying over--if you enjoy pain.
I am looking for a way to auto install a missing perl module when my script runs. I would like to use cpan plus since it "seems" to available on both Windows and Linux but maybe I could have a way to drop down to standard cpan if cpan plus is not installed.
So how could one go about this? There is of course the cpan plus / cpan modules but are those able to integrated into a script?
Check this module: Carton Carton in CPAN, so first you installed all modules for your script, then you will make special dependency file under Carton and as result using this special file in other PC to install all dependency for you script. Please read description of this module in CPAN.
I hope it will help you.
There are multiple installers for cpan modules available; I know of at least CPAN.pm (comes with perl,) CPANPLUS, and cpanminus.
What is the difference between the three?
What situations call for using one over the other?
Are there other module installers I should know about?
CPAN.pm (cpan) is the original client. It comes with Perl, so you already have it. It has the most features. It has a lot of configuration options to customize the way it works, though virtually everyone accepts the default installation. It integrates easily with local::lib.
cpanminus (cpanm) is an attempt to make a zero-configuration client that automatically does the right thing for most users. It's also designed to run well on systems with limited resources (e.g. a VPS). It doesn't come with Perl, but it's easy to install. It integrates easily with local::lib.
Its biggest limitation is its lack of configuration. If you want to do something unusual, it may not support it.
CPANPLUS (cpanp) is an attempt to make a CPAN API that Perl programs can use, instead of an app that you use from the command line. The cpanp shell is more of a proof-of-concept, and I don't know of any real advantages to using it.
In summary, I'd recommend either cpan or cpanm. If you have trouble configuring cpan, try cpanm. If your situation is unusual, try cpan.
It's impossible answer this question because it is too subjective. :)
From my point of view: cpanm is the simplest way install perl modules. You can install cpanm with:
curl -L http://cpanmin.us | perl - --sudo App::cpanminus
and after it you can install modules with simple:
cpanm Some::Module
You can use cpanm for mirroring (part of) CPAN to you local machine too, so IMHO cpanm is the best for the most common CPAN needs.
Are there other module installers I
should know about?
If you're using a Linux distribution that packages CPAN modules, then it's worth using their package installation program to install modules. For example, Ubuntu/Debian have a huge number of CPAN modules that you can install using 'apt' and Red Hat/Centos/Fedora have a number that you can install using 'yum'.
CPAN is the standard. cpanminus (cpanm) asks fewer questions (best most of the time). I don't know anyone that uses cpanplus.
Since what these modules do is download, compile and install (place files in correct places) they all should do the same task. Some of the difference has to do with the permissions level you have. Perhaps you want to install some things local to your user and some things globally then you need a finer adjustment. Developers may also need to control/interrupt the process for debugging etc.
For daily use, use cpanm, unless you are too lazy to install it, then CPAN is fine.
cpanm uses much less memory. This makes it a better choice for environments where RAM is limited, such as shared hosting servers, where regular cpan might die before completing installation task, due to attempting to use more than available memory.
According to cpanm's (1.7044) documentation "When running, it requires only 10MB of RAM"
I have been using perlbrew to manage multiple versions of perl on a Linux Fedora notebook. I have used it with great benefit to run command-line scripts mostly using App::cmd.
I now want to move to running web applications written using CGI::Application using different perls installed in my $HOME. I am familiar with running Perl web applications in $HOMEs using Apache's user_dir or creating Virtual Hosts but I am unable to come up with a clean way of integrating this and the perlbrew managed perls. Specifically I need help in understanding and finding answers to these questions:
How do install mod_perl under perlbrew?
Assuming this is done, how do I configure my VirtualHost so that it picks up the correct perl that is current?
If this is not possible, (which I doubt) can I at least use local installations to run vanilla CGI?
Thank you for your attention.
I don't think this is a good use for perlbrew, which moves around symlinks under its own directory. The trick is switching the mod_perl module around. Remember, mod_perl is going to be binary-incompatible between major versions of perl, and that you will have to compile it against apache for each version of perl (and apache) you want to use.
perlbrew really does two big things for you:
Installs perl, which is trivially easy to do on your own.
Switches around symlinks so perl is whatever version you want.
If you give up on that last one, perlbrew isn't really doing that much for you. I don't think the symlink feature is particularly valuable.
I think perlbrew is fine for what it is, but when you start doing things outside of its limited scope, it's time to not use it. It's supposed to be a tool to save you some time and headache, so if it's not accomplishing that goal, it's not the right tool for your situation.
In this situation, where I'm supporting a single, big web application, I give it its own perl installation that I don't let anything else use.
For your other questions:
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You shouldn't have to configure any VirtualHost stuff. If you are using mod_perl, perl is already in there and you don't get to choose a perl. If you're using CGI stuff, you specify the perl on the shebang line. You will have to ensure apache picks up the right library directories, but I think perlbrew handles that. You might have to use SetEnv or something similar in your httpd.conf.
For vanilla CGI, just point to the right (symlink) path for whatever the default perlbrew version is. The CGI program will just use whatever perl that path points to.
See brian d foy's answer for why not to expect to use perlbrew to switch between versions of mod_perl. I also expect that you will need to run multiple Apache servers, if you need multiple different Perl versions under mod_perl.
However, using perlbrew as an easy way to build Perl is IMHO a valid thing to do, and there are few instructions available for how to run mod_perl under perlbrew.
First ensure perl is built with shared library support, by passing the -Duseshrplib flag (otherwise on 64-bit systems you will get a confusing build failure about -fPIC):
perlbrew install perl-5.16.3 -Duseshrplib
Install the development Apache libraries for your system. On Debian, this differs depending on the Apache MPM that you are using. For the prefork MPM:
sudo apt-get install apache2-prefork-dev
Or for the worker MPM:
sudo apt-get install apache2-threaded-dev
Then you need some options to build and install mod_perl2 into the right place. Note that this means cpanm will fail to build it, but you could use it to get hold of the source:
cpanm mod_perl2 # fails
cd ~/.cpanm/latest-build/mod_perl-2.0.8/ # adjust mod_perl version
Adjust the version of Perl below accordingly. (The MP_APXS option is to give the right path for Debian-based systems, which you might not need.)
perl Makefile.PL MP_APXS=/usr/bin/apxs2 \
MP_AP_DESTDIR=$HOME/perl5/perlbrew/perls/perl-5.16.3/
make
make install
Finally, change the LoadModule line in your Apache configuration file (adjusting paths accordingly):
LoadModule perl_module <your homedir>/perl5/perlbrew/perls/<your perl>/usr/lib/apache2/modules/mod_perl.so
Your mod_perl installation will now be running the version of Perl that you want. Install all your required CPAN modules and get going.
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.