It is good to have fun and learn. And, have fun learning. One of the reasons I have done Perl all these years is that I always have fun with it, unlike other languages where I didn't find it fun to be using and writing.
Anyways, don't be hesitant to use modules that aren't part of the distrobution. There is a lot of useful modules out there that will save you time and headaches. To learn, it is always good to read the modules POD and source to see what makes it tick.
Unless you are using a module which is specific to Win32, or *nix specific, then don't worry about portability. Many modules work fine on many platforms. If you have a reluctant sysadmin, you can still install modules under your home directory. Then you can change @INC to look there, or PERL5LIB.
In order to allow users to install their own modules I have sometimes aliased 'perl' with 'perl -I/path/to/their/modules' which has worked nicely.
@INC lookups are done last added first. Thus, if you added a directory, but the module you're use-ing or require-ing isn't there, it looks in the next entry in @INC. You already have a number of entries that are default. use lib 'somedir'; simply says "Look here first. If it isn't here, then look where you would've looked if I hadn't done this."
As for you installing your own modules ... Learn more about Unix first. It sounds like you're a newbie to Unix in general. You'll have more headaches installing modules than you know what to do with. Of course, if you don't mind that, you'll learn a heck of a lot about Unix installing modules...
As for learning Unix, go to a local library and borrow some books. It's a big learning curve, so don't expect to be an expert in a week, month, or even a year. But, you can expect to become at least proficient in a week or two.
------ We are the carpenters and bricklayers of the Information Age.
Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.
I wholeheartedly agree with KM. Just for the sake of completeness,
I will mention some arguments against using non-standard modules:
Learning how to do something yourself may be a
worthwhile learning experience.
The module that does what you need may include
a lot of extra functionality that you are not going to use. In those
cases, sometimes it's good to peek under the hood and only
extract the functionality you need (giving proper credit, and
ideally asking for permission from the author) and putting
it directly in your program
Of course, this only applies to modules that do relatively
simple things. If you need to do database access or write
a CGI script. By all means, please, use the modules. There's
no need to reinvent the wheel, particularly when it's a complex
I agree with the first part of your argument, you can learn
some excellent stuff by looking at what has already been
done in other modules.
However for anything other than learning, and your own pet
projects, I would certainly recommend using non-standard
modules (non-standard meaning modules not distributed with perl). I am not saying this because you might reinvent
the wheel, but there is a huge part of good programming
that people here seem to never think about: maintenance!
If you copy and paste code from a module into your own
code then you are stuck maintaining that code forever.
only do you have to maintain the code specific to your
project, but also the code that is general in purpose.
Say there were actual bugs in the code you
copied over, then instead of fixing the bug your self, you
just use the CPAN module and grab the latest release (letting
someone else fix the bugs for you).
But of course
there are some problems using the module approach, if the author
decides to change the API from one version to the next then
you have to modify your code to use the new version.
But that is why I would not recommend for production code
using modules with lower version numbers or ones that in
the documentation say they are 'alpha' or 'beta' modules.
Other than that, include what ever you think might be handy.
Of course I recognize there are exceptions to every
rule, like critical speed performance. But for most large
applications, I just wanted to mention that I think
maintenance should be a significant consideration. We may
leave a project, but our code lives on forever! Something to think
Update: Anyone what to bother telling me why this node is a negative reputation? If you have a counter argument let me hear it, otherwise I still think the advise is pretty sound.