Megasus. 25 Perl Module die man kennen sollte Marcus Thiesen v 0.1 marcus@cpan.org

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1 Megasus 25 Perl Module die man kennen sollte Marcus Thiesen v 0.1 marcus@cpan.org

2 Inhalt Megasus, huh? Perl, ähhm? Module, wat? CPAN Die Module Für's Web Für's OO Zum debuggen Für Daten Für den Rest

3 Megasus Marcus' Extremely Genuine Autmated SILC User Support Läuft in #luusa Kann alles Wetter holen RSS Feeds Überwachen Googeln dict.leo.org abfragen machen (CVS)

4 Perl Irssi hat eine Perl Schnittstelle RAD ist nur möglich mit einer kompletten Bibliothek einfach benutzbaren Komponenten guter Dokumentation

5 Module Perl 5 Erweiterungsmechanismus CPAN enthält eine gigantische Anzahl von Modulen Module Objekte

6 Module package Foo; sub hello { print Hello World\n ; } #dann später use Foo; Foo::hello();

7 Enter Exporter Exporter.pm sorgt dafür das man Funktionen einfach benutzen kann use File::Spec::Functions; my $config = catdir($env{home}, 'foo');

8 Perl Objekte I Ein Perl Objekt ist eine Referenz auf ein (Hash Array Scalar) die einen Verweis auf ein Package enthält. package MyClass; sub new { my $class = shift; #sollte MyClass sein } my $ref = {}; return bless $ref, $class; #wenn ich $ref->foo aufrufe, dann schaue in $ref nach welches #Package/Class gemeint ist und rufe $class::foo($ref) auf.

9 do wie require ohne den Lookup in %INC use vs. require vs. do require schaut in %INC nach compiliert und lädt das Modul falls es noch nicht geladen wurde runtime use Name ruft require auf ruft Name->import auf (Exporter) compiletime runtime

10 Gaanz viele Module Leider auch eine Menge dead Camels search.cpan.org (kobesearch.cpan.org) Bugs (rt.cpan.org) CPAN Shell (perl -MCPAN -e shell) CPANPLUS... Debian (lib...-perl)

11 Die Module Für's Web Für's OO Zum debuggen Für Daten Für den Rest

12 Für's Web 1: LWP::Simple use LWP::Simple; my $contents = get ' if ($contents) { print 'Got it'; }

13 Für's Web 2: XML::RSS use LWP::Simple; require XML::RSS; my $contents = get $somefeed; if ($contents) { my $rss = XML::RSS->new; $rss->parse($contents); print join \n, map { $_->{'title'} {'items'}} }

14 Für's Web 3: HTML::TokeParser use LWP::Simple; require HTML::TokeParser; my $contents = get $someurl; if ($data) { my $p = HTML::TokeParser->new(\$data); if (my $title = $p->get_tag('title')) { print $p->get_trimmed_text; } }

15 Für's Web 4: CGI use CGI; print header, start_html('paste here'), start_form, "Paste here:", br, textarea('value','', 40, 110), br, submit, end_form, end_html;

16 Für's Web 5: Template Toolkit template Hallo [% name %] [% FOREACH line = text %] [% line %] [% END %] require Template; my $data = { name => 'Marcus', text => ['dies ist', 'die letzte', 'zeile'], } my $t = new Template; $t->process('template', $data)

17 Und Sonst? CGI::Application Strip::HTML HTML::TagFilter Interfaces für Amazon Google Yahoo Wetterdienst

18 Für's OO 1: Class::Accessor package Foo; use base qw(class::accessor); Foo->mk_accessors(qw(this that whatever)); # Meanwhile, in a nearby piece of code! # Class::Accessor provides new(). my $foo = Foo->new; my $whatever = $foo->whatever; # gets $foo->{whatever} $foo->this('likmi'); # sets $foo->{this} = 'likmi'

19 Für's OO 2: Module::Pluggable package MyClass; use Module::Pluggable; # and then later... use MyClass; my $mc = MyClass->new(); # returns the names of all plugins installed # under MyClass::Plugin::* = $mc->plugins();

20 Für's OO 3: Class::Contract package ClassName use Class::Contract; contract { inherits 'BaseClass'; invar {... }; class attr 'shared' => SCALAR; ctor 'new'; method 'methodname'; pre {... }; failmsg 'Error message'; post {... }; failmsg 'Error message'; } impl {... };

21 Für's Debuggen: diagnostics #!/usr/bin/perl -w use strict; use warnings; use diagnostics; $foo = 'bar'; Global symbol "$foo" requires explicit package name at./t.pl line 7. Execution of./t.pl aborted due to compilation errors (#1) (F) You've said "use strict vars", which indicates that all variables must either be lexically scoped (using "my"), declared beforehand using "our", or explicitly qualified to say which package the global variable is in (using "::").

22 Für's Debuggen: Devel::Size use Devel::Size qw(size total_size); my $size = size("a string"); = (1, 2, 3, 4, 5); my $other_size = size(\@foo); my $foo = {a => [1, 2, 3], b => {a => [1, 3, 4]} }; my $total_size = total_size($foo);

23 Für's Debuggen: Carp::Trace use Carp::Trace; sub flubber { die "You took this route to get here:\n". trace(); }

24 Für's Debuggen: Devel::DProf perl -d:dprof test.pl dprofpp %Time ExclSec CumulS #Calls sec/call Csec/c Name main::bar main::foo warnings::begin strict::bits strict::import warnings::import main::begin

25 Für DBs: Class::DBI package Music::DBI; use base 'Class::DBI'; Music::DBI->connection('dbi:mysql:dbname', 'username', 'password'); package Music::Artist; use base 'Music::DBI'; Music::Artist->table('artist'); Music::Artist->columns(All => qw/artistid name/); Music::Artist->has_many(cds => 'Music::CD'); package Music::CD; use base 'Music::DBI'; Music::CD->table('cd'); Music::CD->columns(All => qw/cdid artist title year/); Music::CD->has_many(tracks => 'Music::Track'); Music::CD->has_a(artist => 'Music::Artist'); Music::CD->has_a(reldate => 'Time::Piece', inflate => sub { Time::Piece->strptime(shift, "%Y-%m-%d") }, deflate => 'ymd', );

26 Für DBs: Class::DBI (II) package Music::Track; use base 'Music::DBI'; Music::Track->table('track'); Music::Track->columns(All => qw/trackid cd position title/); #-- Meanwhile, in a nearby piece of code! --# my $artist = Music::Artist->create({ artistid => 1, name => 'U2' }); my $cd = $artist->add_to_cds({ cdid => 1, title => 'October', year => 1980, }); # Oops, got it wrong. $cd->year(1981); $cd->update;

27 Für DBs: SQL::Translator require SQL::Translator; my $translator = SQL::Translator->new(debug => 0); $translated = $translator->translate(from => 'MySQL', to => $target, data => \$sql, ); # Oracle, MySQL, SQLite, PostgreSQL

28 DateTime my $dt2 = DateTime->now(); my $dt3 = DateTime->from_epoch( $time ); my $duration_object = new DateTime::Duration(days=> 2); $dt2 = $dt + $duration_object; $dt3 = $dt - $duration_object; $duration_object = $dt - $dt2; $dt->set( year => 1882 ); $dt->set_time_zone( 'Europe/Berlin' );

29 File::Modified require File::Modified; my $d = File::Modified->new(files=> ['Import.cfg','Export.cfg']); while (1) { my (@changes) = $d->changed; if (@changes) { print "$_ was changed\n" $d->update()}; }; sleep 60;

30 Regexp::Common use Regexp::Common qw /URI/; if ($msg->text =~ /($RE{URI}{HTTP})/) { print $1; }

31 Time::Duration my $start_time = time(); use Time::Duration; # then things that take all that time, and then # ends: print "Runtime ", duration(time() - $start_time), ".\n";

32 Text::Compare my $tc = new Text::Compare( memoize => 1, stip_html => 0 ); my $sim = $ts->similarity($text_a, $text_b); #$sim will be between 0 and 1 # second way (cache lists): my $tc2 = new Text::Compare( strip_html => 1 ); # make a language sensitive word hash: my %wordhash = $tc2->get_words($some_text); $tc2->first_list(\%wordhash); foreach my $list (@wordlists) { #list is a hashref $tc2->second_list($list); print $tc2->similarity();

33 Und weiter? Curses::UI GraphViz::ISA::Multi Graph Class::Persist Bugs reporten Authoren freuen sich über jedes Feedback

34 THE END Fragen? Richtigstellungen? Meinungen? Danke! Mein nächster Vortrag handelt nicht von Perl :-)