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

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.