Re: How to Teach artists Perl w/out Modules

[Sol-Invictus]

Under Linux/Unix you can install CPAN or any other module in your user account and run it from there. If you don't have much diskspace you can just install the modules you need, though dependencies can make life awkward (see the trouble shooting section). Installing perl modules is fairly straight forward:

1. make a site_perl folder somewhere in your user account :

[SHELL PROMPT ]$ mkdir site_perl

2. set the environment variable PERL5LIB :

[SHELL PROMPT ]$ cd ~ 

# check for shell configuration files
[SHELL PROMPT ]$ ls -al 

(for sh, bash, ksh, or zsh shells - example used: bash)
[SHELL PROMPT ]$ pico ./.bashrc 
[PICO PROMPT ]$ export PERL5LIB=$HOME/path/to/my/site_perl

(for csh or tcsh shells - example used tcsh)
[SHELL PROMPT ]$ pico ./.cshrc 
[PICO PROMPT ]$ set PERL5LIB=/path/to/my/site_perl

you can check if it's set correctly by typing:

[SHELL PROMPT ]$ echo $PERL5LIB

This only affects the Environment variables of the shell, not the system, so you may have to logout and re-login in before the new path will become active. If the echo command still doesn't seem to print anything, or, if it prints something different from what you typed even after logging out and in, then the variable hasn't been set correctly. Repeat the last few steps again to set the new path.

3. FTP the module into your site_perl folder

[SHELL PROMPT ]$ cd /path/to/your/site_perl
[SHELL PROMPT ]$ ftp ftp.CPAN.org/pub/CPAN
login: anonymous
ftp> get /path/to/yourmodule.tar.gz  [space]/path/to/your/site_perl/yo
+urmodule.tar.gz
ftp> quit
221 Goodbye.

4. DECOMPRESS the file:

[SHELL PROMPT ]$ gzip -d yourmodule.tar.gz

5. UNPACK the file :

[SHELL PROMPT ]$ tar -xvf yourmodule.tar

6. BUILD the module (sometimes unnecessary):

[SHELL PROMPT ]$ perl Makefile.PL LIB=/path/to/my/site_perl \
INSTALLMAN1DIR=/path/to/my/man/man1 \
INSTALLMAN3DIR=/path/to/my/man/man3 

[SHELL PROMPT ]$ make 

[SHELL PROMPT ]$ make test

7. INSTALL the module:

[SHELL PROMPT ]$ make install

8. Troubleshooting:

If you get errors about a file not being created:

i. create the path to the file as it was written in the error
ii. install again.

If the error says a module is missing - this is caused by dependancy, in other words the module you want uses another module:

i. FTP the missing module from ftp.CPAN.org into your site_perl folder as before
ii. go through the installation process as before.

After installation, in your scripts and cgis, insert the line (perl versions 5.002 and later):

 
use lib '/path/to/my/site_perl';

or for earlier perls (5.001 and before):

 
BEGIN { unshift(@INC, "/path/to/my/site_perl") }

so the perl interpreter will know to check your site_perl dir for modules.

Installing CPAN.pm

CPAN.pm was designed to free you out from the circular hell of dependancy. Follow the installation procedure as above, once installed and you've checked that the path to your site_perl folder is set correctly in the ENVIRONMENT variables you can start up the CPAN shell by typing:

[SHELL PROMPT ]$ perl -MCPAN -e shell

the first time you run it you'll be prompted for config info, in most cases the default values are fine (just press enter without writing anything), but you must make sure you set the following two correctly for either CPAN.pm, or any modules it installs, to work correctly:

cpan> cpan_home: /path/to/my/site_perl/ANY_NAME_YOU_WANT 

cpan> makepl_arg: LIB=/path/to/my/site_perl 

you can check these values in the CPAN shell at any time by typing: 

cpan> o conf

which outputs a listing of all the config variables* similar to this:

cpan> o conf
CPAN::Config options and /Users/Sol-Invictus/site-perl/.cpan/CPAN/MyCo
+nfig.pm:
    commit             Commit changes to disk
    defaults           Reload defaults from disk
    init               Interactive setting of all options

    build_cache        10
    build_dir          /Users/Sol-Invictus/site-perl/.cpan/build
    cache_metadata     1
    cpan_home          /Users/Sol-Invictus/site-perl/.cpan
    dontload_hash     
    ftp                /usr/bin/ftp
    ftp_proxy          
    getcwd             cwd
    gzip               /usr/bin/gzip
    histfile           /Users/Sol-Invictus/site-perl/.cpan/histfile
    histsize           100
    http_proxy         
    inactivity_timeout 0
    index_expire       1
    inhibit_startup_message 0
    keep_source_where  /Users/Sol-Invictus/site-perl/.cpan/sources
    lynx               
    make               /usr/bin/make
    make_arg           
    make_install_arg   
    makepl_arg         
    ncftp              
    ncftpget           
    no_proxy           
    pager              /usr/bin/less
    prerequisites_policy ask
    scan_cache         atstart
    shell              /bin/tcsh
    tar                /usr/bin/tar
    term_is_latin      1
    unzip              /usr/bin/unzip
    urllist           
        ftp://ftp.ayamura.org/pub/CPAN/
        ftp://ftp.cpan.jp/CPAN/
        ftp://ftp.dti.ad.jp/pub/lang/CPAN/
        ftp://ftp.jaist.ac.jp/pub/lang/perl/CPAN/
        ftp://ftp.kddlabs.co.jp/CPAN/
        ftp://ftp.meisei-u.ac.jp/pub/CPAN/
        ftp://ftp.ring.gr.jp/pub/lang/perl/CPAN/
        ftp://ftp.u-aizu.ac.jp/pub/CPAN
        ftp://mirror.nucba.ac.jp/mirror/Perl/
        ftp://mirror.Mazic.org/pub/CPAN
        ftp://cpan.topend.com.au/pub/CPAN/
        ftp://ftp.planetmirror.com/pub/CPAN/
        ftp://mirror.aarnet.edu.au/pub/perl/CPAN/
        ftp://cpan.in.freeos.com/pub/CPAN/
        ftp://ftp.cbn.net.id/mirror/CPAN
        ftp://ftp.mweb.co.id/pub/languages/perl/CPAN/
    wait_list         
        wait://ls6-www.informatik.uni-dortmund.de:1404
    wget

*note: the first 3 are commands

To run this config script again at any time type (in the CPAN shell):

cpan> o conf init

See the relevant MAN page or PODs for more information on how to set or unset these variables individually, either:

[SHELL PROMPT]$ perldoc CPAN

or:

[SHELL PROMPT]$ man CPAN

Once installed correctly, adding other modules to your site_perl becomes a breeze - just type:

[SHELL PROMPT ]$ perl -MCPAN -e shell
cpan> install MODULE_YOU_WANT

and CPAN.pm does the rest (including installing any other fish hooked modules). Equally as useful, through CPAN you can check for newer releases of existing modules and automatically install them as they become available, much like a package management system. For a brief summary of CPAN.pm's commands use the CPAN shell's own internal help function:

cpan> ?