====== Perl ======

===== CPAN =====

==== To install Modules Locally ====

local::lib enables you to install modules into a specified directory, \\
without requiring root or administrator access. See the bootstrapping technique for how to get started.\\
You can create a directory per user/project/company and deploy to other servers,\\
by copying the directory (as long as you are on the same operating system).


[[http://search.cpan.org/~apeiron/local-lib/ | CPAN Local::lib ]]\\
But you can also manually do it.

**First export your username**

<code bash>
 export username=ketan
</code>

<note warning>Still you have to modify / change "$username" manually at many places</note>

**create the .cpan directories**

<code oobas>
 mkdir $HOME/.cpan/
 mkdir $HOME/.cpan/CPAN/
 # This is so it ignores the global CPAN config

 echo "\$CPAN::Config->{cpan_home}='/home/$username/.cpan';" > /home/$username/.cpan/CPAN/MyConfig.pm
</code>
Then Execute a CPAN shell

<code oobas>
 perl -MCPAN -e shell
OR
 cpan
</code>
Then when in the shell type:

<code oobas>
 o conf init
</code>
<note>to reconfigure CPAN, replace all */root/.cpan/* with  /home/$username/.cpan/*</note>

change the makepl_arg so it should look like.

<code bash | /home/$username/.cpan/CPAN/MyConfig.pm>
 'makepl_arg' => q[INSTALLDIRS=site PREFIX=/home/$username/perl/],
</code>
Finally the env variable PERL5LIB needs to point to the new module installation paths:

<code oobas>
 export PERL5LIB="/home/$username/perl/share/perl/custom_lib/:/home/$username/perl/lib/perl/custom_lib/";
</code>
and then you should be able to use CPAN to install modules.

I then modified following file

<code bash | ~/.bashrc>
export PERL_LOCAL_LIB_ROOT="/home/$username/perl";
export PERL_MB_OPT="--install_base /home/$username/perl";
export PERL_MM_OPT="INSTALL_BASE=/home/$username/perl";
export PERL5LIB="/home/$username/perl/share/perl/custom_lib/:/home/$username/perl/lib/perl/custom_lib/";
export PATH="/home/$username/perl/bin:$PATH";
</code>