Can I use a local::lib if local::lib isn't installed globally and without eval-ing it in shell?

Question

I have a problem, I want to use local::lib; in a script. But because I need to use this script many places, I don't want to try adding the eval to bashrc, every time I install this script to a server. and I can't get local::lib installed globally (in the default @INC) on the servers. Is there any way I can use local::lib from within the script so that it knows where the module local::lib is without the eval that local::lib recommends and without installing it into a directory in the default @INC on the server?

Answer 1

Something like this at the top of your script should work, though I have local::lib installed on all my boxes in the regular @INC so it's untested–

use lib "/path/to/local/lib's/lib";
use local::lib "/path/to/specific/local-lib/base/you/want";

I would recommend having local::lib installed the same way, in the default @INC with your main env perl. The various local repositories it can create are not tied to its location proper.

Answer 2

You need to know at least where local::lib was installed, and you won't get around specifying this, so you need one shell command or environment variable declaration. Assuming you used the default for --bootstrap, this is a minimal example in bash for Perl to find the library:

# persistent for this shell only
export PERL5LIB=$PERL5LIB:$(perl -MConfig -e'print "$ENV{HOME}/perl5/lib/perl5/$Config{archname}:$ENV{HOME}/perl5/lib/perl5"')
perl yourprog
perl yourprog
perl yourprog

or just

# environment for one run of perl only
PERL5LIB=$PERL5LIB:$(perl -MConfig -e'print "$ENV{HOME}/perl5/lib/perl5/$Config{archname}:$ENV{HOME}/perl5/lib/perl5"') perl yourprog

It is safe to simply hard-code the directory names and thus avoid the eval and call to perl.

use local::lib; will find and load the module from the extended @INC. Inspect %INC to see the specific location if you actually need that.

Caveat: You cannot use local::lib now to install additional modules, that needs the rest of the declarations made in the usual eval it prints out.

---

Setting environment vars from within with the reexecution trick as per urgh below.

use autodie qw(:all);
unless ($ENV{REEXEC}) {
    $ENV{REEXEC} = 1;
    $ENV{PERL5LIB} = …
    exec $^X, $0;
}
# main starts here