How do I tell CPAN to install all dependencies?

Question

How do I tell CPAN to install all dependencies?

I tried setting these in cpan:

cpan> o conf prerequisites_policy follow
cpan> o conf commit

I still had to answer "y" a couple of times (but fewer than before it feels like).

Is there a way to get it to always go ahead and install? I want to make it unattended.

It would seem that I want a flag to always trust CPAN to do the right thing, and if it suggests an answer I would like to follow it (always hit Enter when it asks something).

Solution 1

Here is the one-liner making these changes permanent including automatic first-time CPAN configuration:

perl -MCPAN -e 'my $c = "CPAN::HandleConfig"; $c->load(doit => 1, autoconfig => 1); $c->edit(prerequisites_policy => "follow"); $c->edit(build_requires_install_policy => "yes"); $c->commit'

Or combine it with local::lib module for non-privileged users:

perl -MCPAN -Mlocal::lib=~/perl5 -e 'my $c = "CPAN::HandleConfig"; $c->load(doit => 1, autoconfig => 1); $c->edit(prerequisites_policy => "follow"); $c->edit(build_requires_install_policy => "yes"); $c->commit'

Run it before using the CPAN shell or whatever.

Solution 2

Try setting PERL_MM_USE_DEFAULT like so:

PERL_MM_USE_DEFAULT=1 perl -MCPAN -e 'install My::Module'

It should make CPAN answer the default to all prompts.

Solution 3

The latest and greatest answer to this question is to use cpanm instead (also referred to as App::cpanminus or cpanminus)!

DESCRIPTION

cpanminus is a script to get, unpack, build and install modules from CPAN and does nothing else.

It's dependency free (can bootstrap itself), requires zero configuration, and stands alone. When running, it requires only 10MB of RAM.

To bootstrap install it:

curl -L http://cpanmin.us | perl - --sudo App::cpanminus

or if you are using perlbrew simply

perlbrew install-cpanm

or from cpan itself:

cpan install App::cpanminus

From then on install modules by executing (as root if necessary)

cpanm Foo::Bar

Solution 4

Changing the following parameter on top of prerequisites_policy follows.

cpan> o conf prerequisites_policy 'follow'
cpan> o conf build_requires_install_policy yes
cpan> o conf commit

This will change it from "ask/yes" to "yes" and stop it asking you.

Solution 5

Here's what I'm pretty sure you're looking for:

cpan> o conf prerequisites_policy follow
cpan> o conf commit

View more solutions

Comments

[silbana]

Are the prompts related to downloading module source? If so, see connect_to_internet_ok option. Otherwise, tell us what other prompts you are trying to avoid.

[Nifle]

Well all basically, these last ones was "optional modules".

[brian d foy]

The problem is things that auto-install on their own. CPAN.pm doesn't get a chance to handle that stuff. See tsee's answer.

[Geoff]

Any way to make this persistent, so you can just type "install My:Module" into cpan each time and it will remember this? Edit Config.pm?

[andersand]

If you're on linux, add the line export PERL_MM_USE_DEFAULT=1 to your ~/.bashrc

[OrangeDog]

Link now appears to be dead

[Yann Sagon]

If you get an error Can't locate object method "install" via package "xxx" at -e line 1. add a "+" right before the module name.

[reinierpost]

I have this problem when I use cpanm, so telling me to use it is not the solution here.

[Joel Berger]

rather than a blind comment, please ask as a new question and link here. I suspect a permissions issue might be your problem

[William Turrell]

This does not answer the question - the OP wants a way to automatically install dependencies / automatically respond to prompts.

[Vladimir Marchenko]

In fact, it does install dependencies and automatically responds to prompts. I use it all the time, including this very moment. But there is a need for a small modification: yes|/root/bin/perl -MCPAN -e "CPAN::Shell->notest(qw!install Your::Module!)"

[filimonov]

isn't it the same as in @sdf anwer?

[Peter Mortensen]

What is "yes" supposed to do?

[Dat TT]

Thanks! I need these two options so that it did not ask me again and again!

[ikegami]

You can pass specific settings to init. For example, o conf init prerequisites_policy. That way, you don't have to go through the long initialization process, but still get the friendly prompt for the setting in question

[ikegami]

Note that these are the default values for these settings.

[Pablo Bianchi]

On an Ubuntu 18.04 I installed with sudo apt install cpanminus make.

[Richard Smith]

Down-voting. Don't recommend that people execute the output of curl.

[Scott Prive]

Up-voting. "The output of curl" is how to install a great MANY things, from k8s to (on some systems) Docker. The curl is used in context of a legitimate project, not random advice to run curl output, but besides that it is out of scope to impose your personal policy here. Be aware you can always save the curl to disk, inspect it then run it.