HKUST Spring 2013 COMP 2021 Unix & Script Programming Final Project - LightHTML

1. Light</HTML>

7. list - ls [options] elements

8. clean - cl elements

9. delete - de [options] elements

10. delete - de [options] elements

11. DEMO

12. Dispatch Table
hash of references to executable code

13. Dispatch Table
my $dispatchTable = {
! a => &func_a,
! b => &func_b,
! q => sub { exit(0) },
};
while ( 1 ) {
! print "Press a key!n";
! chomp (my $input = <STDIN>);
! if (defined $dispatchTable->($input)) {
! ! $dispatchTable->{$input}->();
! }
}
Hash table
Get user input
reference to function argvs

14. Dispatch Table
my $myFunc = {
! s => &saveFile,
! de => &deletTag,
! cl => &cleanUp,
! ls => &listTags,
! q => sub { $root = $root->delete; exit(0) },
! DEFAULT => sub {print ("Command not found.n")}
};

15. HTML::TreeBuilder
Parser that builds a HTML syntax tree
http://search.cpan.org/~cjm/HTML-Tree-5.03/lib/HTML/TreeBuilder.pm

16. HTML::Tree
make parse trees out of
HTML source
HTML::TreeBuilder
builds the parse trees
HTML::Element
parse trees are made up of
element class objects

17. create tree object
HTML::TreeBuilder
#!/usr/bin/perl -w
use warnings FATAL => 'all';
use strict;
use HTML::TreeBuilder;
use Term::ANSIColor;
(@ARGV == 1) || exit print "Usage: [HTML file].n";
(-e $ARGV[0]) || exit print "Input file does not exist.n";
my $root = HTML::TreeBuilder->new;
$root->parse_file($ARGV[0]) || die "$!";
include module

18. html
head
title meta
body
p
h1,h2...div
p p

19. Perl & LWP
by Sean M. Burke
"Fetching web pages, Parsing HTML,
Writing Spiders, & More"
http://lwp.interglacial.com/index.html
Chapter 9
HTML Processing with Trees
Chapter 10
Modifying HTML with Trees

20. Light</HTML>
GitHub : LightHTML
https://github.com/Conrad-Lo/LightHTML