Reading the Modern Perl Book

I’m in the Perl phase of my language obsession rotation. I’ve created a handy language obsession table you can use to simulate the behavior for your favorite GURPS Geek campaign.

Roll 3d6 for the subject.

Every week after the first, roll 1d6.

Alternately, you can set a duration of 1d6 weeks. That’s handy for an ADHD NPC geek, where you don’t want to check every week. Note that this is free time obsession. The language at $work is whatever $work requires.

I don’t know why I felt the need to share this. I’ve already spent more time on that silly table than the actual subject I wanted to write about.

So anyways - I’m messing about with Perl. I have been reading chromatic’s Modern Perl blog for a while - even when I’m not in a Perl cycle. It’s good, you should try it out. He presents a needed perspective on Perl as something more than a musty system administration language.

chromatic is also writing a book and maintaining the draft on github. I finally decided I wanted to read that draft. The README and a tiny bit of Git knowledge provide all I need.

$ git clone git://github.com/chromatic/modern_perl_book.git
$ cd modern_perl_book
$ perl build/tools/build_chapters.pl

Now there is a handful of POD files in build/chapters which I could read with perldoc.

$ ls build/chapters
chapter_01.pod  chapter_03.pod  chapter_05.pod  chapter_07.pod  chapter_09.pod  chapter_11.pod  chapter_13.pod  chapter_15.pod
chapter_02.pod  chapter_04.pod  chapter_06.pod  chapter_08.pod  chapter_10.pod  chapter_12.pod  chapter_14.pod  chapter_16.pod
$ perldoc build/chapters/chapter_01.pod

I can also generate HTML for those days when perldoc just isn’t making me happy.

$ perl build/tools/build_html.pl
Can't locate Pod/PseudoPod/HTML.pm in @INC (@INC contains: /usr/local/lib/perl5/5.10.1/darwin-2level /usr/local/lib/perl5/5.10.1 /usr/local/lib/perl5/site_perl/5.10.1/darwin-2level /usr/local/lib/perl5/site_perl/5.10.1 /usr/local/lib/perl5/site_perl .) at build/tools/build_html.pl line 6.
BEGIN failed--compilation aborted at build/tools/build_html.pl line 6.

Oops. It looks like there’s a dependency. No problem.

$ sudo cpan Pod::PseudoPod::HTML
$ perl build/tools/build_html.pl
$ ls build/html
chapter_01.html chapter_04.html chapter_07.html chapter_10.html chapter_13.html chapter_16.html
chapter_02.html chapter_05.html chapter_08.html chapter_11.html chapter_14.html style.css
chapter_03.html chapter_06.html chapter_09.html chapter_12.html chapter_15.html

Now I can open the chapters in my favorite Web browser.

$ elinks build/html/chapter_01.html

From here, I can pay attention to chromatic’s tweets — or his dents, since he seems more active on Identi.ca - or watch the modern_perl_book repository on github. Whenever he mentions new content, I will refresh and rebuild.

$ git pull
$ perl build/tools/build_chapters.pl
$ perl build/tools/build_html.pl

I don’t want to remember three whole commands. Am I taking Laziness too far? Perhaps. Nevertheless, here’s a Perl script to handle the task. It should only rebuild the chapters and HTML if there was an update in the repository.

#!/usr/bin/env perl
# refresh.pl

use Modern::Perl;

my $git_pull = `git pull`;

if ( $git_pull =~ m{\AAlready up-to-date.} ) {
    say "No changes to book.";
}
else {
    print $git_pull; # Show what updates were made.

    say "Building chapters.";
    system qw(perl build/tools/build_chapters.pl);

    say "Building HTML.";
    system qw(perl build/tools/build_html.pl);

    say "All done. Enjoy the update!";
}