1. Defined/Undef my $i; if( defined $i ) #false $i=0; if( defined $i ) #true my %hash; #or %hash=(); defined %hash; #false, hash is empty $hash{“1”}=“one”; exists($hash{“1”})==defined($hash{“1”})==true; undef $hash{“1”}; exists($hash{“1”})== false; defined($hash{“1”})==true; delete $hash{“1”}; exists($hash{“1”})== false; defined($hash{“1”})==false;

2. Basic HTML Document Title Hello World!

3. www.nonocnn.com/ www.nonocnn.com/some/ Webserver displays a default (in most cases) file: index.html if it doesn’t exist then all files in that directory are listed. To protect server information, usually this option (file listing) is switched off. File Names

4. Paragraph Next Paragraph. And line break. Unordered List (UL): We Love Perl. We Love Perl IN BOLD We Loooove Perl Now, We Love HTML Too! Horizontal rule (HR): Ordered List (OL): We Love Perl. We Love Perl IN BOLD We Loooove Perl Now, We Love HTML Too!

5. Link To www.cs.tau.ac.il Images: Image Options: Tables: Cell 1.1 Cell 1.2 Cell 2.1 Cell 2.2

6. Table Options: Cell--------------------1.1 Cell--------------------1.2 Cell--------------------2.1 Cell--------------------2.2 Aligned left Aligned right

7. CGI - Common Gateway Interface CGI – a standard that defines the protocol between a web server and a application (script). Web Browser Web Server Application DB CGI http/ ssl … search example

8. Sending information to CGI http://www.tau.ac.il/cgi-bin/scilib.pl?searchj=protein Two ways to submit information: HTML form With URL

9. CGI - Simple script #!/usr/bin/perl use CGI qw(:standard); print header; $param= param('formtext'); print " Hello CGI: $param"; print end_html;