Cgi

G I R I S H S R I V A S T A V A
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Objective
 After the completion of this training,
participants will able to understand about
perl scripting and cgi programming aspects.
 Topics Covered:
 Introduction of CGI
The Definition
Web Browsing
Architecture of CGI
How does CGI works
Preparing CGI for work 7/5/2013
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Cont…
 Introduction to Perl
 The CGI.pm Module
 Pattern Matching
 Arrays
 Dealing With Files In PERL
 Basic HTML
 What is cgi-lib.pl?
 Communicating with databases
 Sending mail with Perl – CGI Scripts
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Dynamic Web
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 When the Web first started, there were only static
HTML pages.
 The internet had been around for some time already,
but it was only after the introduction of HTML.
 A lot has happened since then.
 We would like to place the birth of the dynamic web to
when CGI, Common Gateway Interface, was first
introduced in 1993.
 CGI was a way to let a website run scripts (usually Perl
scripts back then) on the web server and display the
output.

CGI (Common Gateway Interface)
 A standard protocol for interfacing external
application software with an information server,
usually a web server.
 It is basically a set of rules used to describe
the way in which a web server communicates
with other software housed on the same
machine, and then how that software talks
back to the web server.
 What is returned from the CGI program is
based on what was requested, and this
information can be accessed and returned to
the user in many different ways.
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Definition of CGI
 The Common Gateway Interface, or CGI, is a set of
standards that define how information is exchanged
between the web server and a custom script.
 CGI is a standard interface that sits between the web
browser and the web server.
 When the browser makes a request of the server, all
of the request details flow into the server through the
input interface of the CGI.
 When the server responds with its output, the
information flows back out through the output
interface of the CGI.
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Cont…
 CGI programs can be written in any language.
 Perl is a very common language for CGI
programming as it is largely platform independent
and the language‟s features make it very easy to write
powerful applications.
 However, some CGI programs are written in C, shell
script, or other languages.
 It is important to remember that CGI is not a
language in itself.
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Some Things to Remember About CGI
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 CGI is not the program itself.
 CGI is simply the interface between the Web page or
browser and the Web server that runs the program.
 You must have CGI access to run programs on your
Web page.
 Any program or script that will run on your Web
server, can be used as a CGI program.
 Most people use Perl to write their CGI scripts, but
other languages include C and C++, Tcl, and UNIX
shell scripts.

Uses of CGI Scripts
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 CGI scripts are used to resolve form data, put that data
in to databases, send the data out as an email message,
respond to the form entry with email or another Web
page, and much more.
 CGI scripts also are used for behind the scenes
interaction with Web readers.
 They can set and read cookies, get and tabulate
information such as browser and operating system,
calculate hit counts, and monitor Web traffic.

Why Use CGI?
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 Many of the uses of CGI can be duplicated by newer
technology such as JavaScript and ActiveX.
 The primary benefit to using CGI rather than browser based
scripting is that you can be sure that all of your readers (with
very few exceptions) will be able to use the program.
 Java, JavaScript, and ActiveX can all be turned off within the
browser, and many browsers simply don't support them.
 Also, it is becoming more common for company firewalls to
disallow these technologies to work in their system (often for
security or bandwidth reasons).
 Because CGI scripts are run on the external Web server, they
are not limited by browser or firewall limitations.

Why Not Use CGI?
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 The biggest drawback to CGI Scripts is that they can put a lot
of load on a Web server.
 The Web browser will time out (usually after around 5
minutes), but often the server will continue to run the
program until a system administrator comes in and shuts off
the faulty script.
 The browser based scripting tools mentioned above have the
advantage of running off the reader's computer.
 They use the processor locally rather than on the Web server
itself, and so are less intense on the Web server.

Comparing Server-Side Web Languages
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 Php - Probably currently most popular! But not a general purpose language.
 Perl - Older than Php. More difficult to use, but general purpose. Good
for general Unix system admin tasks.
 ASP.NET - Microsoft‟s server-side language; commercial; platform
dependent.
 Python - Object oriented multi-purpose scripting language. Really good
for server-side tasks! But not that well known.
 Java Servlets - Java server-side programming, requires Apache Tomcat
engine or similar.
 JSP - Sun‟s version of Java server-side programming.

Java Scripts And Other Web Technologies…
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 Scripts come in many different formats such as JavaScript,
VBScript, ActiveX, Active Server Pages (ASP), Java Applets,
JavaBeans, CGI and others.
 JavaScript can do some things, however they have
limitations and can only work on the client-side.
 In other words, the scripts are interpreted and run in
the browser of the user.
 CGI scripts, on the other hand, will directly interact with
the server, where your whole web site resides, simply they
are server-side.
 Since it works from your server you can take control over
the scripts which are running by using other
server files (for example the sendmail program of Unix).

Cont…
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 JavaScripts don't access any of your other files, (for
example you cannot access a database which is in your
server).
 JavaScripts are simply inserted into your HTML pages,
which can be run by the browser.
 Netscape browsers don't support VBScripts and ActiveX, so
are not usually used by the typical web user.
 Another technology like ASP can be used instead of CGI but
only in a Windows-NT server as UNIX servers do not
support them.
 Java applets can also be used, however speed can be a
problem so many users prefer CGI scripts.

Web Browsing
 To understand the concept of CGI, lets see what
happens when we click a hyper link to browse a
particular web page or URL.
 Your browser contacts the HTTP web server and demand for
the URL ie. filename.
 Web Server will parse the URL and will look for the filename in
if it finds that file then sends back to the browser otherwise
sends an error message indicating that you have requested a
wrong file.
 Web browser takes response from web server and displays
either the received file or error message.
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CGI Architecture Diagram
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How does CGI work?
CGI
1. HTTP
request
2. Call CGI
3. CGI
program‟s
response
4. HTTP
response
User
Web
Browser
(on client)
Application
(on server)
Server
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Introduction to CGI
(continued)
 CGI programs work as follows:
 STEP 1 (On the client side): Get Information from the user
(using HTML forms,, Java Applet, …,etc).
 STEP 2 (On the server side): Process the data, connect to
DATABASE, search for PATTERNS, …,etc.
 STEP 3 (On the server side): Send the result of computation
back to the client.
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Preparing CGI for work
 The steps involved in preparing a CGI program
for work.
1. Contact your Web host to find out where you should
put your CGI programs on the server. Usually it will
be a directory on the server named “cgi-bin”.
2. Set up the access permission of directory “cgi-bin”
using the following UNIX command:
chmod 755 cgi-bin/
3. Set up the access permission of the CGI program
using the following UNIX command:
chmod 755 cgi-program
4. Test your CGI program from the server command
line to make sure it works perfectly before
publishing it.
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History of Perl
 Perl was introduced in 1987
 reason for its creation was that Mr. Wall was
unhappy by the functionality that sed, C, awk and the
Bourne Shell offered him. He looked for a language
that will combine all of their best features, while
having as
few disadvantages
of its own.

Cont… A brief history of Perl
 Perl became especially popular as a language for
writing server-side scripts for web-servers.
 But that's not the only use of perl, as it is
commonly used for system administration tasks,
managing database data, as well as writing GUI
applications.

 written by Larry Wall
 A GNU product FREE, Open
Source software
 Interpreted and not compiled!
 Originally designed for UNIX®, but
is portable to other O/S
 stable, cross platform programming
language
Introduction

What does Perl stand for?
 „Perl‟ isn‟t really an acronym
 2 favorite expansion:
-- Practical Extraction Report Language
-- Pathologically Eclectic Rubbish Lister
 It's not PERL or P.E.R.L.
 'Perl' refers to the language
 'perl' to the interpreter that runs the programs
written in Perl

What is Perl and why is it so great?
 Perl is a stable, cross platform programming language.
 Perl stands for Practical Extraction and Report
Language.
 Perl is a general purpose computer language ideally
suited to handling words and text.
 The quote of Perl gurus, “It makes the easy things easy,
and the difficult things possible.”
 Perl's strengths is that there are usually many ways of
accomplishing any particular bit of programming.
 This strength inspires Perl programmers to quote the
motto "TIMTOWTDI" (pronounced "timtoady") - the
acronym of "There Is More Than One Way To Do It."
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Perl Features
 Perl takes the best features from other languages,
such as C, awk, sed, sh, and BASIC, among others.
 Perls database integration interface (DBI) supports
third-party databases including Oracle, MySQL
and others.
 works with HTML, XML, and other mark-up
languages.

Cont… Perl Features
 supports Unicode.
 supports both procedural and OO programming.
 extensible.
 The Perl interpreter can be embedded into other
systems.

Perl & the Web
 Perl is the most popular web programming
language due to its text manipulation capabilities
and rapid development cycle.
 Perl is widely known as "the duct-tape of the
Internet".
 Perl's CGI.pm module, part of Perl's standard
distribution, makes handling HTML forms simple.
 Perl can handle encrypted Web data, including e-
commerce transactions.

Cont… Perl and the Web
 Perl can be embedded into web servers to speed up
processing by as much as 2000%.
 mod_perl allows the Apache web server to embed a
Perl interpreter.
 Perl's DBI package makes web-database integration
easy.
mod_perl is an optional module for the Apache HTTP server. It
embeds a Perl interpreter into the Apache server, so that dynamic
content produced by Perl scripts can be served in response to incoming
requests, without the significant overhead of re-launching the Perl
interpreter for each request.

What is needed to run Perl CGI programs?
 There are several things you need in order to
create and run Perl CGI programs.
 a web server
 web server configuration which gives you
permission to run CGI
 a Perl interpreter
 appropriate Perl modules, such as CGI.pm
 a shell account is extremely useful but not
essential
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Setting up Perl/CGI
 First, you need to get Perl if you do not already have
it installed.
 Go
to http://www.activestate.com/Products/ActivePerl/
Download.html and download the latest release for
Windows.
 Next, you need a Web server.
 http://httpd.apache.org/download.cgi
 Scroll down to locate Win32 Binary without
crypto (no mod_ssl) (MSI Installer).
http://www.webdevelopersnotes.com/how-do-i/install-apache-windows-7.php
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First CGI Program
 #!C:Perlbinperl.exe
 use CGI;
 print "Content-Type: text/htmlnn";
 print "<HTML>n";
 print "<HEAD>n";
 print "<TITLE>Hello World</TITLE>n";
 print "</HEAD>n";
 print "<BODY>n";
 print "<H4>Hello World</H4>n";
 print "<P>n";
 print "Your IP Address is $ENV{REMOTE_ADDR}.n";
 print "<P>";
 print "<H5>Have a nice day</H5>n";
 print "</BODY>n";
 print "</HTML>n";
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Explanation
 The first line of your program should look like this:
 #!C:Perlbinperl -wT
 The first part of this line, #!, indicates that this is a script. The next
part, C:Perlbinperl.exe, is the location (or path) of the Perl
interpreter.
 The final part contains optional flags for the Perl interpreter.
Warnings are enabled by the -w flag. Special user input taint
checking is enabled by the -T flag. Taint mode tells Perl to keep track
of data that comes from the user and avoid doing anything insecure
with it.
 print "Content-type: text/htmlnn";
 This is a content-type header that tells the receiving web browser
what sort of data it is about to receive — in this case, an HTML
document. If you forget to include it, or if you print something else
before printing this header, you'll get an "Internal Server Error"
when you try to access the CGI program.
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Introduction to PERL
 To run PERL programs:
 On UNIX, type the command from UNIX shell:
perl perl_prog.pl
 On Windows, type the command from DOS prompt:
perl perl_prog.pl
 PERL is a case-sensitive language just like C
or Java.
 “#”sign is used for comments in PERL
 Example:
#!/usr/bin/perl
# This program is to . . .
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Programming Standards
 The following coding standards should be followed:
 Start the program with a header comment giving info about
the PERL path, programmer, copyrights, last modified date,
and description.
 Example:
#!/usr/bin/perl
######################################
# Girish Srivastava
# Copyrights © 2001
# All rights reserved.
#
# Last modified 9/16/2001
# This program is to . . .
######################################
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Programming Standards
(Continued)
 Use three-line-comment style. Example:
#
# Incrementing variable $count.
#
$count++;
 Use meaningful names for variables or
subroutines. Capitalize every word except the first
one. Example:
$myBuffer=1;
sub printThankYouMessage(){
…}
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PERL Data Types
 PERL has three built-in data types: scalars, arrays of
scalars, and associative arrays of scalars, known as
"hashes".
 Scalar Variables
 A scalar may contain one single value in any of three
different flavors: a number, a string, or a reference.
 Scalar values are always named with '$„ at the beginning,
even when referring to a scalar that is part of an array or a
hash. Examples:
$day #A simple scalar value "day"
$day[28] #the 29th element of @day
$day{'Feb'} #The 'Feb' value from %day
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PERL Data Type
(Continued)
 Array Variables
 An array is basically a way to store a whole bunch of scalar
values under one name.
 An array name begins with an "@" symbol. Examples:
@arrayName = ("element1", "element2");
@browser = ("NS", "IE", "Opera");
@one_two_thre = (1, 2, 3);
 To access a single element is an array, use a $+array
name+[ + index+]. Array indexing starts form zero.
Examples:
$arrayName[0] # the first element of the
# array
$browser[1] # This will return „IE‟.
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PERL Data Type
(Continued)
 Associative Arrays “Hashes”
 Associative arrays are created with a set of key/value
pairs. A key is a text string of your choice that will
help you remember the value later.
 A hash name begins with % sign. Examples:
%hashName = ('key1', 'value1', 'key2',
'value2');
%ourFriends = ('best', 'Don', 'good', 'Robert',
'worst', 'Joe');
 To access an element, use $+hash name+{+key+}.
Examples:
$hashName{„key1‟} #This will return value1
$ourFriends{'good'} #This will return
#„Robert‟
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Example
 #!C:Perlbinperl.exe
 my $text = 'cool guy';
 my $string = "some $text";
 print $string; # prints literally “some cool guy”;
Arrays
#!C:Perlbinperl -w
#DEFINE SOME ARRAYS
@days = ("Monday", "Tuesday", "Wednesday");
@months = ("April", "May", "June");
#PRINT MY ARRAYS TO THE BROWSER
print @days;
print @months;
Hashes
#!C:Perlbinperl -w
#DEFINE SOME HASHES
%hashName = ('key1', 'value1', 'key2', 'value2');
%ourFriends = ('best', 'Don', 'good', 'Robert', 'worst',
'Joe');
#PRINT MY HASHES TO THE BROWSER
print $hashName{'key1'};
print $ourFriends{'good'};
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Operators
 PERL uses:
 Arithmetic operations: +, -, *, /, %,**.
 Relational operations: <, >, <=, >=, ==.
 String Operations: eq, ne, lt, gt, le, ge.
 Assignment Operators: =, +=, -+, *=, /=, .=.
 Increment/decrement operators: ++, --.
 Boolean operations: &&, ||, !.
 Quotation marks:
 ”” character string with variable interpolation.
 ‟‟ character string without variable interpolation.
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#!C:Perlbinperl.exe
$one = 1;
$two = 2;
$three = 3;
$four = 4;
$abcd = "abcd";
$pqrs = "pqrs";
$xyz = "xyz";
# concantenate the two strings and print
print $abcd . " another stringn";
# repeat the string abcd three times
print $abcd x $three . "n";
# add the data in variables one and two.
The numerical value is converted to string
and concantenated with n
print $one + $two . "n";
print $three % $two . "n";
# modulo - returns the remainder of three
divided by two
print $three ** $two . "n";
# exponentiation - three raised to power
two
print $one++ . "n";
# post increment
print ++$one . "n";
# pre increment
print $one-- . "n";
# post decrement
print --$one . "n";
# pre decrement
$one += $two;
# $one = $one + $two
$one -= $two;
# $one = $one - $two

Control Structures
 Control structures include conditional statements,
such as if/elsif/else blocks, as well as loops
like foreach, for and while.
 if ($varname > 23) { # do stuff here if the condition is true }
 if ($varname > 23) {
 print "$varname is greater than 23";
 } elsif ($varname == 23) {
 print "$varname is 23";
 } else {
 print "$varname is less than 23"; }
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#!C:Perlbinperl.exe
my $number = 95;
if($number eq 92)
{
print 'Number is ninety-five!';
}
else
{
print 'Number is not ninety-five';
}

Unless
 unless is similar to if. Let's say you wanted to execute code
only if a certain condition were false. You could do
something like this:
 if ($varname != 23) { # code to execute if $varname is not 23 }
 The same test can be done using unless:
 unless ($varname == 23) { # code to execute if $varname is not 23 }
 There is no "elseunless", but you can use an else clause:
 unless ($varname == 23) {
 # code to execute if $varname is not 23 }
 else {
 # code to execute if $varname IS 23
 }
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Looping
 Loops allow you to repeat code for as long as a condition is met. Perl
has several loop control structures: foreach, for, while and until.
 Foreach Loops
 foreach iterates through a list of values:
 foreach my $i (@arrayname) {
 # code here
 }
 This loops through each element of @arrayname, setting $i to the
current array element for each pass through the loop. You may omit the
loop variable $i:
 foreach (@arrayname) {
 # $_ is the current array element
 }
 This sets the special Perl variable $_ to each array element. $_ does not
need to be declared (it's part of the Perl language) and its scope
localized to the loop itself.
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Cont…
 For Loops
 Perl also supports C-style for loops:
 for ($i = 1; $i < 23; $i++) {
 # code here
 }
 While Loops
 A while loop executes as long as particular condition is true:
 while (condition) {
 # code to run as long as condition is true
 }
 Until Loops
 until is the reverse of while. It executes as long as a particular condition is
NOT true:
 until (condition) {
 # code to run as long as condition is not true
 }
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#!C:Perlbinperl.exe
@array = ("value1", "value2", 1, 2, 3, 4);
foreach my $value (@array)
{
print $value;
}
#!C:Perlbinperl.exe
$integer = 0;
while($integer < 50)
{
print $integer;
$integer++;
}
Until
#!C:Perlbinperl.exe
$firstVar = 10;
until ($firstVar > 12)
{
print("inside: firstVar = $firstVarn");
$firstVar++;
}
print("outside: firstVar = $firstVarn");
This program displays:
inside: firstVar = 10
outside: firstVar = 13

Exercise
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1. Create a program using PERL, which gives the output
as per the following figure:
*
* *
* * *
* * * *
* * * * *

Breaking from Loops
 There are several ways to break from a loop. To stop the current loop
iteration (and move on to the next one), use the next command:
 foreach my $i (1..20) {
 if ($i == 13) {
 next;
 }
 print "$in";
 }
 This example prints the numbers from 1 to 20, except for the number 13.
When it reaches 13, it skips to the next iteration of the loop.
 To break out of a loop entirely, use the last command:
 foreach my $i (1..20) {
 if ($i == 13) {
 last;
 }
 print "$in"; }
 This example prints the numbers from 1 to 12, then terminates the loop
when it reaches 13.
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Cont…
 next and last only effect the innermost loop structure, so if you have
something like this:
 foreach my $i (@list1) {
 foreach my $j (@list2) {
 if ($i == 5 && $j == 23) {
 last; }
 } # this is where that last sends you
 }
 The last command only terminates the innermost loop. If you want to
break out of the outer loop, you need to use loop labels:
 OUTER: foreach my $i (@list1) {
 INNER: foreach my $j (@list2) {
 if ($i == 5 && $j == 23) {
 last OUTER; }
 }
 } # this is where that last sends you
 The loop label is a string that appears before the loop command (foreach,
for, or while). In this example we used OUTER as the label for the outer
foreach loop and INNER for the inner loop label.
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The CGI.pm Module
 Perl offers a powerful feature to programmers: add-on
modules.
 These are collections of pre-written code that you can
use to do all kinds of tasks.
 Some modules are included as part of the Perl
distribution; these are called standard library
modules and don't have to be installed. If you have
Perl, you already have the standard library modules.
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Cont…
 Let's see how to use a module in your CGI program. First
you have to actually include the module via the use
command. This goes after the #!C:Perlbinperl.exe line
and before any other code:
 use CGI qw(:standard);
 Note :we're not doing use CGI.pm but rather use CGI.
The .pm is implied in the use statement.
The qw(:standard) part of this line indicates that we're
importing the "standard" set of functions from CGI.pm.
 Now you can call the various module functions by typing
the function name followed by any arguments:
 functionname(arguments)
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Cont…
 A function is a piece of code that performs a specific
task; it may also be called a subroutine or a method.
 Functions may accept optional arguments (also
called parameters), which are values (strings,
numbers, and other variables) passed into the function
for it to use.
 The CGI.pm module has many functions; for now we'll
start by using these three:
 header;
 start_html;
 end_html;
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Cont…
 The header function prints out the "Content-type"
header. With no arguments, the type is assumed to be
"text/html".
 start_html prints out the <html>, <head>, <title> and
<body> tags. It also accepts optional arguments. If you
call start_html with only a single string argument, it's
assumed to be the page title. For example:
 print start_html("Hello World");
 will print out the following*:
 <html>
 <head> <title>Hello World</title>
 <head>
 <body>
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Cont…
 The end_html function prints out the closing HTML
tags:
 </body>
 </html>
 print header;
 print start_html("Hello World");
 print "<h2>Hello, world!</h2>n";
 print end_html;
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Basic HTML
 HyperText Markup Language
 HTML is the language used to prepare hypertext
document.
 Web browsers are used to view HTML documents
and display data to users
7/5/2013
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HTML Document
<html>
<head><title>Test Page</title></head>
<body>
<b>Hello, world</b>
</body>
</html>
Document Structure
- Head
- Body
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HTML Tags
 HTML tags are commands, they tell the browser how
to display the text.
 There are opening and closing versions for many tags
opening tag: <HTML>
closing tag: </HTML>
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HTML Tags (continued)
 <HTML></HTML> For identifying a text document as an HTML
document
 <HEAD></HEAD> For creating the head section of page
 <BODY></BODY> For enclosing the main section of page
 <B></B> For displaying text in boldface
 <I></I> For displaying text in italics
 <OL></OL> For creating ordered lists
 <A></A> For creating links
 <FORM></FORM> For creating fill-in forms
 <P> For creating a new paragraph
 <BR> For creating a line break
 <INPUT> For creating form elements
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HTML Tags (continued)
The affected text is contained within the tags
 <B>Hello</B> ------- Hello
 <I>Bye!</I> ---------- Bye
 Ordered list
<OL>
<LI>Apple</LI>
<LI>Banana</LI>
<LI>Orange</LI>
</OL>
1. Apple
2. Banana
3. Orange
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HTML Form
 <FORM> and </FORM> mark the beginning and
the end of a form
 Form establishes the relationship between the
form page and the script that will process the
current form data
 HTML forms are the user interface that provides
input to your CGI scripts
- Collecting data
- Accepting commands
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HTML Form (continued)
<HTML><HEAD>
<TITLE>My first html page</TITLE></HEAD>
<BODY>
<FORM method=post action=“aftersubmit.cgi”>
Name: <INPUT type=text name=“uname"><BR>
Password: <INPUT type=password
name=“upwd"><BR>
<INPUT type=submit>
<INPUT type=reset>
</FORM>
</BODY></HTML>
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The <FORM> Tag
 <FORM method=post action=“aftersubmit.cgi”>
Tag attributes specify the properties for the element
 Method determines how the form data is sent to the
script
- GET-- delivers form data by appending it to
the URL of the script
- POST-- sends the data as a body of text
 action
specifies the address of the script that is going to
process the current form data
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The <INPUT> Tags
 INPUT
- is an element of the form
- creates a wide variety of interface widgets
 <INPUT type=text name=“uname">
 Attribute “type”— the appearance and features
<INPUT type=text>-------text field
<INPUT type=submit>-----submit button
<INPUT type=reset>------reset button
<INPUT type=password>---password field
<INPUT type=hidden>-----hidden field
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The <INPUT> Tag (continued)
 INPUT attribute "name"
identifies each user interface element
<input type=text name=“uname">
<input type=password name=“upwd">
 INPUT attribute "value"
contains associated information that is also sent to
the script.
<input type=text name=“uname">
<input type=text name=“uadd">
<input type=text name=“ucity“
value=“Edmonton”>
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Form Submission
<FORM method=post action = “aftersubmit.cgi”>
 The browser assembles the form data (name and
password) into a series of name/value pairs
 The browser delivers data to the server and then
the script
“aftersubmit.cgi”
 The script “aftersubmit.cgi” can retrieve the
element value by using its name (uname and
upwd)
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Forms: Checkbox
 Checkboxes allow the viewer to select one or more options on a form. If
you assign each checkbox field a different name, you can print them the
same way you'd print any form field using param('fieldname').
 Here is the HTML code for a set of checkboxes:
 <b>Pick a Color:</b><br>
 <form action="colors.cgi" method="POST">
 <input type="checkbox" name="red" value=1> Red<br>
 <input type="checkbox" name="green" value=1> Green<br>
 <input type="checkbox" name="blue" value=1> Blue<br>
 <input type="checkbox" name="gold" value=1> Gold<br>
 <input type="submit"> </form>
 This example lets the visitor pick as many options as they want — or none,
if they prefer. Since this example uses a different field name for each
checkbox, you can test it using param:
 my @colors = ("red","green","blue","gold");
 foreach my $color (@colors) {
 if (param($color)) {
 print "You picked $color.n"; } }
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Cont…
 Since we set the value of each checkbox to 1 (a true value), we didn't need
to actually see if param($color) was equal to anything — if the box is
checked, its true. If it's not checked, then param($color) is undefined and
therefore not true.
 The other way you could code this form is to set each checkbox name to
the same name, and use a different value for each checkbox:
 <input type="checkbox" name="color" value="red"> Red<br>
 <input type="checkbox" name="color" value="green"> Green<br>
 <input type="checkbox" name="color" value="blue"> Blue<br>
 <input type="checkbox" name="color" value="gold"> Gold<br>
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Cont…
 param('color') returns a list of the selected
checkboxes, which you can then store in an array.
Here is how you'd use it in your CGI program:
 my @colors = param('color');
 foreach my $color (@colors)
 {
 print "You picked $color.<br>n";
 }
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Radiobutton
 <input type="radio" name="color" value="red"> Red<br>
 <input type="radio" name="color" value="green"> Green<br>
 <input type="radio" name="color" value="blue"> Blue<br>
 <input type="radio" name="color" value="gold"> Gold<br>
 Cgi code:
 Since the viewer can only choose one item from a set
of radio buttons, param('color') will be the color that
was picked:
 my $color = param('color');
 print "You picked $color.<br>n";
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Basic Setup
 That's the basic set up for a CGI form, but what
happens after the user presses Submit? Consider, for
example, this simple form:
 Name:
E-mail:
 SUBMIT
 Here's the chain of events when the user hits
"Submit":
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Cont…
 When the user presses Submit, the browser sends the form data
to the web server.
 The web server launches the CGI program which was written to
process this form.
 The CGI program does whatever it does with the data. The
program might consult a database, perform calculations on the
data, use the data to add the user to a mailing list, whatever the
programmer wants it to do. Whatever else the program does, it
generates a web page using HTML so the user can see the results
of submitting the form.
 The CGI program passes the HTML back to the web server.
 The web server passes the HTML back to the browser.
 So there are three pieces to the CGI process: the form
on your web page, the web server, and the CGI
program. 7/5/2013
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Exercise
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73
 Create an html form having multiple radio buttons
showing different different colors. If you select any of
the radio button and press submit, then it will call
appropriate cgi page and the background color of
that page will be same as the color which you have
selected from the list.

Pattern Matching
 Almost every script you write in Perl will have some
kind of pattern matching operation .
 Patterns are subject to an additional level of
interpretation as a regular expression. This is done
as a second pass, after variables are interpolated.
 To use pattern matching in Perl, first we figure out
what we want to find, we write a regular expression
to find it, and then we stick that pattern in a
situation where the result of finding.
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Cont…
 The Binding Operator
 When you do a pattern match, you need three things:
 the text you are searching through
 the pattern you are looking for
 a way of linking the pattern with the searched text
 As a simple example, let's say you want to see whether a string
variable has the value of "success". Here's how you could write
the problem in Perl:
 $word = "success";
 if ( $word =~ m/success/ ) {
 print "Found successn";
 } else {
 print "Did not find successn"; }
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Cont…
 There are two things to note here.
 First, the "=~" construct, called the binding operator, is what
binds the string being searched with the pattern that specifies
the search. The binding operator links these two together and
causes the search to take place.
 Next, the "m/success/" construct is the matching
operator, m//, in action. The "m" stands for
matching to make it easy to remember. The slash
characters here are the "delimiters". They
surround the specified pattern. In m/success/, the
matching operator is looking for a match of the
letter sequence: success.
 Generally, the value of the matching statement returns 1 if
there was a match, and 0 if there wasn't. 7/5/2013
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Regular Expressions
 Regular expressions are very powerful tools for matching,
searching, and replacing text.
 All pattern matching in Perl is based on this concept of
regular expressions.
 Regular expressions form a standard way of expressing
almost any text pattern unambiguously.
 Special Characters
 Some special characters or combinations of characters have a
special meaning and do not represent themselves.
 This is what give regular expressions their power.
 For example, the lowly period does not stand for a period in a
match. Instead, it stands for any character.
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Cont…
 The pattern /b.g/ would match "bag", "big", "bug",
etc, as well as any other sequence: "b2g", "b&g",
"b]g" and so on.
 Matching simply means "found somewhere,
anywhere, within the searched string".
 You can use special characters to specify the position
where the search pattern must be located.
 A ^ character stands for the beginning of the searched string, so:
 /^success/ would match "success" but not "unsuccessful".
 A $ character stands for the end of the searched string, so:
 /success$/ would match "unsuccess" but not "successful".
 Using both ^ and $ together nails the pattern down at both ends, so:
 /^success$/ will only match the exact string "success".
7/5/2013
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Cont…
 Other special characters include:
 - a form of a "quote" character
| - alternation, used for "or'ing"
() - grouping matched elements
[] - character class
 The first character, "", is used in combination with
special letters to take away their special meaning.
E.g.:
 . will match a period
$ will match a dollar sign
^ will match a caret
will match a backslash
 and so on.
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Cont…
 Repetition Characters
 The expressions above show you how to match
certain characters, but they don't allow you to
control how many matches should be made at once.
Matching repetition is controlled by a few other
special characters:
 + means 1 or more matches
* means 0 or more matches
? means 0 or 1 matches
{n} exactly n matches
{m,n} m to n matches
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"Hello world!" to be changed to "Hello mom!"
instead.
 $mystring =~ s/world/mom/;
 print $mystring;
 Prints "Hello mom!". The substitution operator s/// replaces the pattern
between the s/ and the middle /, with the pattern between the
middle / and last /. In this case, "world" is replaced with the word "mom".
 Now change "Hello mom!" to say "Goodby mom!".
 $mystring =~ s/hello/Goodbye/;
 This does not substitute, and prints "Hello mom!" as before. By default,
the search is case sensitive. As before, use the pattern
modifier i immediately after the trailing / to make the search case-
insensitive.
 Okay, ignoring case, change "Hello mom!" to say "Goodby
mom!".
 $mystring =~ s/hello/Goodbye/i;
 Prints "Goodby mom!".
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Process form with regular expression: first name
and last name
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 <html>
<head>
<title>form page</title>
</head>
<body>
<p>here's my test form</p>
<form method = "post" action = "/cgi-bin/RegExpExample.cgi">
<p>First name:
<input name = "firstName" type = "text" size = "20"></p>
<p>Last name:
<input name = "lastName" type = "text" size = "20"></p>
<p>Phone number:
<input name = "phone" type = "text" size = "20"></p>
<p>Date (MM/DD/YY):
<input name = "date" type = "text" size = "20"></p>
<p>Time (HH:MM:SS):
<input name = "time" type = "text" size = "20"></p>
<input type = "submit" value = "submit">
<input type = "reset" value = "reset">
</form>
</body>
</html>

Cont…
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 #!C:Perlbinperl.exe
 use strict;
 use warnings;
 use CGI ':standard';
 my $firstName = param( "firstName" );
 my $lastName = param( "lastName" );
 my $phone = param( "phone" );
 my $date = param( "date" );
 my $time = param( "time" );
 print header();
 print start_html( -title => "form page" );
 if ( $firstName =~ /^w+$/ ) {
 print "<p>Hello there Lu$firstName.</p>";
 }
 if ( $lastName =~ /^w+$/ ) {
 print "<p>Hello there Mr./Ms. Lu$lastName.</p>";
 }
 print end_html();

Arrays
 An array stores an ordered list of values. While a
scalar variable can only store one value, an array can
store many. Perl array names are prefixed with an
@-sign. Here is an example:
 my @colors = ("red","green","blue");
 Each individual item (or element) of an array may be
referred to by its index number. Array indices start
with 0, so to access the first element of the array
@colors, you use $colors[0].
 when you're referring to a single element of an array,
you prefix the name with $ instead of @. The $-sign
again indicates that it's a single (scalar) value; the @-
sign means you're talking about the entire array.7/5/2013
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Cont…
 If you want to loop through an array, printing out all
of the values, you could print each element one at a
time:
 print "$colors[0]n"; # prints "red"
 print "$colors[1]n"; # prints "green"
 print "$colors[2]n"; # prints "blue"
 A much easier way to do this is to use a foreach loop:
 foreach my $i (@colors)
 {
 print "$in";}
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Finding the Length of Arrays
 If you want to find out how many elements are in a
given array, you can use the scalar function:
 my @people = ("Howard", "Sara", "Ken", "Josh");
 my $linelen = scalar(@people);
 print "There are $linelen people in line.n";
 Sorting Arrays
 You can do an alphabetical (ASCII) sort on an array
of strings using the sort function:
 my @colors = ("cyan", "magenta", "yellow", "black");
 my @colors2 = sort(@colors);
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Dealing With HTML Components in perl-cgi
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 We can create html form component like: textbox, textarea,
buttons, etc, in CGI.
 use strict;
use warnings;
use CGI;
my $cgi=new CGI;
print $cgi->header(),$cgi-
>start_html("Simple Examples");
print $cgi->center("Centered Text");
print $cgi->p("A Paragraph");
print $cgi->br();
print $cgi->b("Bold"),$cgi->i("Italic");
print $cgi->p("A Paragraph",$cgi->sup("A superscript"));
print $cgi->end_html();

Form Example
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 use CGI;
$co = new CGI;
print $co->header,
$co->start_html(-title=>'CGI Example'),
$co->center($co->h1('Welcome to CGI!')),
$co->start_form(),
$co->textarea
(
-name=>'textarea',
-rows=>10,
-columns=>60
),
$co->end_form(),
$co->end_html;
#!C:Perlbinperl
use CGI ':standard';
print header();
print "Form Elements", br(), br(), br();
print start_form;
print "A Text Box:       ", textfield('surname', 'Default', 50), br();
print "A Select Box:       ", popup_menu('SelectBox', ['Perl', 'Web',
'Development']);
print p, "Text Area:      ", textarea('comments', 'Default Text', 10,
50);
print p, "CheckBoxes: ", checkbox_group('check1', ['one', 'two', 'three']);
print p, "Radio Buttons: ", radio_group('radio1', ['a', 'b', 'c']);
print p, submit();
print end_form;
if (param())
{
print "The surname you entered was: ",em(param('surname')),
p, "The Selections are: ",em(join(", ",param('SelectBox'))),
p, "The comments box contains: ",em(param('comments')),
p, "you selected checkbox: ",em(param('check1')),
p, "you selected radio: ",em(param('radio1'));
}

Dealing With Files In PERL
 Reading Files:
 STEP 1: Open the file for reading:
open(DFH, “data.txt") || die (“Can‟t Open
file”);
 STEP 2: Read the data from the file:
@rawData = <DFH>;
 STEP 3: Close the file:
close(DFH);
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(Continued)
 Writing to files:
 STEP 1: Open the file for writing:
open(DFH, “>data.txt") || die (“Cannot Open
file”);
 STEP 2: Write data to the file:
print DFH “New Data”;
close(DFH);
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(Continued)
 Appending Files:
 STEP 1: Open the file for appending:
open(DFH, “>>data.txt") || die (“Cannot Open
file”);
 STEP 2: Write data at the end of the file:
print DFH “Another data line”;
close(DFH);
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Reading Data File
 When you build large web application, you will
need to store data and retrieve it later
 Text files are the simplest way to maintain data
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Reading And Writing Data File (script)
#!C:Perlbinperl.exe
open(SRC, “file.txt”) || die “Could not open source
file.n”;
open(DST, “>newfile.txt”);
while ( $line = <SRC> )
{
print DST $line;
}
close SRC;
close DST;
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File Handle
 The file handles are just the things we use when we
are dealing with files.
 A file handle is associated with a file by the open
statement.
open (FILE, $filename)
 All the interaction with a file is done by the file
handle.
@filecontent = <FILE> -- get the whole file
$filecontent = <FILE> ---- get the first line
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Writing Data File
#!C:Perlbinperl.exe
use CGI;
$q=new CGI;
print "Content-type: text/htmlnn";
my $name=$q->param("name");
my $outputfile="users.txt";
if (open (OUTPUT, ">>$outputfile")) # open a file
{
print OUTPUT "$namen"; # write the user name to
the file
print "<HTML><BODY>Thank you!
$name</BODY></HTML>";
}
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<html>
<head>
</head>
<body>
<form action="/cgi-bin/FileRead_Html.cgi"
method="post">
<input type="text" name="name">
<input type="submit" name="submit" value="Go">
</form>
</body>
</html>

Writing Data File (continued)
 Opening a file for writing
- For overwriting
open (OUTPUT, ">>$outputfile")
- For appending
open (OUTPUT, ">$outputfile")
 Without “>>” and “>”, the file is opened for reading
open (OUTPUT, "$outputfile")
 Creating the output file and making it writable
touch users.txt
chmod a+w users.txt
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Exercise
7/5/2013
97
 Create a login page using perl-cgi script, read the user name
and password from existing .txt file. After pressing the
submit button it should show the Message of successful or
unsuccessful login.
 Write a Perl script that will take as input a file called
“foo.txt”, produce as output a file called “bar.txt”; lines in
input will be copied to output, except for the following
transformations:
 any line with the string “IgNore” in it will not go to output
 any line with the string “#” in it will have that character and all
characters after it, to end of line, removed
 any string “*DATE*” will be replaced by the current date in output
•We have a file containing lines in different formats.
We want to pick out the lines which start with a digit and
end in a period.

Debugging
 Default response of the server:
"Internal Server Error" --- not useful
 Better ways:
In the script
use CGI::Carp qw(fatalsToBrowser);
In the UNIX shell (check the syntax)
perl -cw scriptname.cgi
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see the error in your browser
instead of the error logs
If you want to do a similar thing with Perl warnings as well,
use this instead:
use CGI::Carp qw(fatalsToBrowser warningsToBrowser);

Debugging (continued)
 use CGI::Carp qw(fatalsToBrowser);
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What is cgi-lib.pl?
 Cgi-lib is a CGI parsing library written by Steven Brenner.
 The cgi-lib.pl library that was become the first standard perl library to
help parse and deal with CGI Web based interfaces.
 The cgi-lib.pl library makes CGI scripting in Perl easy enough for anyone to
process forms and create dynamic Web content. The library has the
following features:
 Extremely simple to learn and easy to use
 Designed for operation under Perl5 and Perl4
 Very efficient
 Compatibility with all CGI interactions
 Compatible with Perl5 security features such as taint, warnings, (command
line options -Tw) and use strict;
 Debugging facilities
7/5/2013
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Cont…
 The cgi-lib.pl Perl library simply consists of handy, easy-to-
use Perl functions. The library is more than simply a means
of processing CGI input. The library includes subroutines to:
 Read and parse CGI input -- a value(s) for a given name can
be easily found.
 Conveniently format CGI output.
 Conveniently return Headers and Bottoms of standard CGI output.
 Conveniently return URLs.
 Conveniently return CGI Error Codes.
 Print in HTML format all name/value pairs input.
 Print in HTML format Environment variables.
 The cgi-lib.pl input routines can accept all and process all
methods of input (e.g. GET and POST methods). You do not
have to worry about which mechanism has been adopted.7/5/2013
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A Sample Form Response CGI Perl Script
 In this subsection we will develop a minimal.pl CGI routine that accepts
input form our minimal form and sends back HTML that echoes the input
data.
 We will use the cgi-lib.pl to
 Parse the input from the form.
 Format the HTML output.
 We will need to learn some more basic Perl:
 How to include and call Perl libraries.
 How to call Perl subroutines
 The first thing our Perl script will need to do is to include the Perl library
file cgi-lib.pl.
 The Perl command require will load in any external Perl file. It is easier and
sometimes essential that all library files exist in the same folder or directory
as the main Perl script calling the library.
 Therefore make sure that all Perl files required for a Perl program do exist
at the same folder or directory level.
7/5/2013
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Cont…
 Thus to include our cgi-lib.pl file we need the Perl command:
 require "cgi-lib.pl";
 Having included the library we can call on its many useful subroutines.
 The &ReadParse() subroutine reads either GET or POST input and
conveniently stores the name/value pairs in a Perl array.
 Thus a Perl call of the form:
 &ReadParse(*input);
 will store the input in an array input.
 & is used to indicate a Perl subroutine call.
 Next we will need to extract out the relevant value of a given name.
 In our current example there is only one input field and we are therefore
only interested in the value associated with the myfield name.
 To get this value you simply do: $input{'myfield'}
 Thus to print out the value typed we could do something like:
 print "You typed: " . $input{'myfield'} . "n";
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http://stein.cshl.org/WWW/CGI/cgi-lib_porting.html

A first minimal Perl script
 minimalExample.html
 <html>
 <head><title>Sample Example</title></head>
 <body bgcolor="white"><form method="post"
 action="/cgi-bin/minimal.cgi">
 Please enter your name:<br>
 <input type="text" name="myfield" size="35"><br>
 <input type="submit" value="Send">
 <input type="reset" value="Reset">
 </form>
 </body>
 </html>
Minimal.cgi
#!C:Perlbinperl
# This is the minimalist form script
# to demonstrate the use of
# the cgi-lib.pl library
require "cgi-lib.pl";
# Read in all the variables set by the form
&ReadParse(*input);
print "Content-Type: text/htmlnn";
print "<html> <head>n";
print "<title>Sample Input</title>n";
print "</head>n";
print "<body>n";
print "You typed: " . $input{'myfield'} . "n";
print "</body> </html>n"; 7/5/2013
104

A second minimal Perl script
 some more cgi-lib.pl subroutines:
 Nearly every CGI output has:
 exactly the same header output.
 similar HTML head information
 similar HTML ending
 Fortunately subroutines exist to save us typing this same
information all the time.
 The &PrintHeader subroutine returns the string:
 Content-Type: text/htmlnn
 Thus we can use print in conjunction to produce our CGI header
output via:
 print &PrintHeader;
7/5/2013
105

Cont..
 The &HtmlTop subroutine accepts a single string
argument, MY TITLE say, and return an HTML Head and Body
(opening only) with the argument as the HTML
page TITLE and H1 Header. I.e.
 <html>
 <head>
 <title>MY TITLE</title>
 </head>
 <body>
 <h1>MY TITLE</h1>
 which is rather useful.
 The &HtmlBot subroutine is the compliment of &HtmlTop and
returns:
 </body>
 </html> 7/5/2013
106

Cont…
 Thus we can use these functions and we only need to provide the main HTML
body ourselves.
 Thus we develop a better minimal.cgi program as follows
 #!C:Perlbinperl
 # minimal.cgi
 # This is the minimalist form script
 # to demonstrate the use of
 # the cgi-lib.pl library
 require "cgi-lib.pl";
 # Read in all the variables set by the form
 &ReadParse(*input);
 # Print the header + html top
 print &PrintHeader;
 print &HtmlTop ("Minimal Input");

 print "You typed: " . $input{'myfield'} . "n";
 print &HtmlBot;
7/5/2013
107

Installing and Using MySQL
 In order to successfully connect to a MySQL database with Perl, you will
first need to ensure that the MySQL drivers are installed on your system.
 DBI (DataBase Interface) and DBD:MySQL (DataBase Driver for MySQL).
 First, we need to start the Perl Package Manager. Click on your start menu
and select the Run...option. In the pop-up window, type cmd and hit
enter.
 This will bring up the Windows command line.
 If you did the default install of ActiveState's ActivePerl, you should be able
to type ppm at the prompt to start the Perl Package Manager.
 First comes the DBI (DataBase Interface) which can be installed by
typing install DBI.
 Finally we install the MySQL driver for the DBI. This is done by
typing install DBD-mysql.
7/5/2013
108

Cont…
 When you are able to do some basic administration tasks, let's create a
database called mydb in mysql.
 And in that database, we will create a simple table called ofuser and
populate it with some data.
 Here is the SQL you'll need to create the table and fill in a few records, just
connect to your MySQL database and run them.
 CREATE DATABASE mydb;
 USE mydb;
 CREATE TABLE ofuser ( id int(10) unsigned NOT NULL
auto_increment, name varchar(128) NOT NULL default '', phone
varchar(128) NOT NULL default '', PRIMARY KEY (id) );
 INSERT INTO ofuser VALUES (1, 'Some Person', '555');
 INSERT INTO ofuser VALUES (2, 'Another Person', '222');
7/5/2013
109

Cont…
 Now that we have a database to connect to, let's look at how we access the
information from our Perl programs. The following is a simple script that
connects to the database and runs a short bit of SQL to retrieve all the
samples.
 use strict;
 use CGI::Carp qw(fatalsToBrowser);
 use DBI;
 my $dbh;
 my $user = "root";
 my $password = "admin";
 print header,
 start_html;
 $dbh = DBI->connect("dbi:mysql:database=mydb;host=localhost:3306;", $user, $password);
 my $sth = $dbh->prepare('select * from ofuser');
 $sth->execute;
 print "<ul>";
 while (my @row = $sth->fetchrow_array) {
 print "<li>@rowt";
 }
 print "</ul>";
 print end_html;
The first thing we need to do is
let the Perl interpreter know
that we intend to use the Perl
DBI function library, by
including it in our program
with the use function.
Next we'll need to create a
connection to the database
itself. For this part of the script,
your mydb database will need
to be running.
Finally we use
the fetchrow_array function
to fetch each row of the results
from the MySQL database and
print them one to a line.
7/5/2013
110

Exercise
7/5/2013
111
 Create an html login form, try to authenticate it via
mysql database and if authentication is valid then it
should go to welcome page displaying your user name
and your details.

Using Cookies in CGI
 HTTP protocol is a stateless protocol.
 But for a commercial website it is required to
maintain session information among different pages.
 For example one user registration ends after
completing many pages.
 But how to maintain user's session information
across all the web pages.
7/5/2013
112

Cont…
 In many situations, using cookies is the
most efficient method of remembering
and tracking preferences, purchases,
commissions, and other information
required for better visitor experience or
site statistics.
7/5/2013
113

Cont…
 How It Works
 Your server sends some data to the visitor's browser in the
form of a cookie.
 The browser may accept the cookie.
 If it does, it is stored as a plain text record on the visitor's
hard drive.
 Now, when the visitor arrives at another page on your site,
the cookie is available for retrieval.
 Once retrieved, your server knows/remembers what was
stored.
7/5/2013
114

Cont…
 Cookies are a plain text data record of 5
variable-length fields:
 Expires : The date the cookie will expire. If this is blank, the cookie will
expire when the visitor quits the browser.
 Domain : The domain name of your site.
 Path : The path to the directory or web page that set the cookie. This
may be blank if you want to retrieve the cookie from any directory or
page.
 Secure : If this field contains the word "secure" then the cookie may
only be retrieved with a secure server. If this field is blank, no such
restriction exists.
 Name=Value : Cookies are set and retrviewed in the form of key and
value pairs.
7/5/2013
115

Example
 Setting up Cookies
 This is very easy to send cookies to browser. These cookies will be sent along
with HTTP Header. Assuming you want to set UserID and Password as cookies.
So it will be done as follows:
 #!C:Perlbinperl.exe
 use strict;
 use CGI qw(:standard);
 use CGI::Carp qw(warningsToBrowser fatalsToBrowser);
 print "Set-Cookie:UserID=XYZ;n";
 print "Set-Cookie:Password=XYZ123;n";
 print "Set-Cookie:Expires=Tuesday, 25-Dec-2012 23:12:40 GMT n";
 print "Content-type:text/htmlrnrn";
 From this example you must have understood how to
set cookies. We use Set-Cookie HTTP header to set
cookies.
#!C:Perlbinperl.exe
use strict;
use CGI qw/:standard/;
use CGI::Carp qw(warningsToBrowser fatalsToBrowser);
my $cookie = cookie(
-name=>'CGI-PERL-COOKIE-EXAMPLE',
value=>'cookie.linuxconfig.org',
-expires=>'+1y');
print header (-cookie=>$cookie),
start_html('CGI Cookie with Exipire Date'),
p("Cookie had been saved !n"),
end_html;
exit;
The following code uses same principles of creating a cookies however on
larger scale. When creating a cookies we need to keep in mind that there
is a limitation of maximum 20 cookies per domain. Use a following code
to create multiple cookies simultaneously. The code first creates a scalar
variable to hold a cookies definitions and then we print a header with
both cookies in form of array.
#!C:Perlbinperl.exe
use strict;
my $cookie1 = cookie(-
name=>'cookie_one',value=>'value1',expires=>'+1d');
my $cookie2 = cookie(-
name=>'cookie_two',value=>'value2',expires=>'+10y');
print header (-cookie=>[$cookie1,$cookie2]),
start_html('CGI Multiple Cookie Example'),
p("Cookies received!n"),
end_html;
exit;
7/5/2013
116

Retrieving Cookies
 This is very easy to retrieve all the set cookies. Cookies are stored in CGI environment
variable HTTP_COOKIE and they will have following form.
 key1=value1;key2=value2;key3=value3....
 Here is an example of how to retrieving cookies.
 #!C:Perlbinperl.exe
 use strict;
 use CGI qw(:standard);
 use CGI::Carp qw(warningsToBrowser fatalsToBrowser);
 my $cookie;my $key;my $val;my $user_id;my $password;
 print "Content-type:text/htmlrnrn";
 my $rcvd_cookies = $ENV{'HTTP_COOKIE'};
 my @cookies = split /;/, $rcvd_cookies;
 foreach $cookie ( @cookies ){
 ($key, $val) = split(/=/, $cookie); # splits on the first =.
 $key =~ s/^s+//;
 $val =~ s/^s+//;
 $key =~ s/s+$//;
 $val =~ s/s+$//;
 if( $key eq "UserID" ){
 $user_id = $val;
 }elsif($key eq "Password"){
 $password = $val;
 }
 }
 print "User ID = $user_idn";
 print "Password = $passwordn";
#!C:Perlbinperl.exe
use strict;
use CGI::Carp qw(warningsToBrowser fatalsToBrowser);
my $retrieve_cookie = cookie('CGI-PERL-COOKIE-EXAMPLE');
print header,
start_html,
p("Cookie value is $retrieve_cookien"),
end_html;
exit;
Similarly the code below retrieves multiple cookies at once:
#!C:Perlbinperl.exe
use strict;
my $retrieve_cookie1 = cookie('cookie_one');
my $retrieve_cookie2 = cookie('cookie_two');
print header,
start_html,
p("COOKIE_ONE Value: $retrieve_cookie1 n"),
p("COOKIE_TWO Value: $retrieve_cookie2 n"),
end_html;
exit;
7/5/2013
117

What is sendmail?
 Sendmail is the most popular Unix-based
implementation of the Simple Mail Transfer Protocol
(SMTP) for transmitting e-mail.
 When a sendmail server receives e-mail, it attempts to
deliver the mail to the intended recipient.
 However, because it does not provide a mailbox facility
and for other reasons, other software such as a POP3
or Internet Message Access Protocol server are also
needed.
 Most Internet service providers (ISPs) provide both an
SMTP server (such as sendmail) and a POP or IMAP
server. 7/5/2013
118

How does sendmail for windows work?
 In perl or php or asp scripts we can write a code to
send mail to mail recepients.
 We direct data to program sendmail.exe who sends
email to person or persons that our script sends.
 So all we need is to send header and email-msg to
sendmail.exe program and that is it.
7/5/2013
119

Installation of sendmail.exe
 All of scripts are in cgi-bin folder (for example
c:Inetpubwwwroottestdomain.comhttpdoc
scgi-bin). "Cgi-bin" folder must have execute
permissions.
7/5/2013
120

Cont…
 Download sendmail.zip
 http://velikan.net/sendmail-for-windows-iis/sendmail.zip
 Now upload sendmail.zip to your cgi-bin folder end
extract contents.
 Next step is to edit sendmail.ini file. You only need
to set your domain and if you do not have your own
smtp server installed on your server you can write
smtp mail server of your internet service provider.
7/5/2013
121

Cont…
That is it. You have successfully installed
sendmail.exe program for windows - now only thing
for you is to use it...
7/5/2013
122

Example
 use CGI qw(:standard);
 use CGI::Carp qw(warningsToBrowser fatalsToBrowser);
 use strict;
 my $title='Perl Mail demo';
 my $to='girish092.ch@gmail.com';
 my $from= 'girish092.ch@gmail.com';
 my $subject='YOUR SUBJECT';
 open(MAIL, "|sendmail/sendmail.exe -t");
 ## Mail Header
 print MAIL "To: $ton";
 print MAIL "From: $fromn";
 print MAIL "Subject: $subjectnn";
 ## Mail Body
 print MAIL "This is a test message from CGI-Perl! You can write your
 mail body text heren";
 close(MAIL);
 print "<html><head><title>$title</title>
 </head>n<body>nn";
 ## HTML content let use know we sent an email
 print "<h1>$title</h1>n";
 print "<p>A message has been sent from $from to $to";
 print "nn</body></html>";
7/5/2013
123

In UNIX
7/5/2013
124
 #!/usr/bin/perl
 $title='Perl Mail demo';
 $to='MAIL ADDRESS TO SEND TO';
 $from= 'webmaster@YOURDOMAIN.COM';
 $subject='YOUR SUBJECT';
 open(MAIL, "|/usr/sbin/sendmail -t");
 ## Mail Header
 print MAIL "To: $ton";
 print MAIL "From: $fromn";
 print MAIL "Subject: $subjectnn";
 ## Mail Body
 print MAIL "This is a test message ! You can write your mail body text heren";
 close(MAIL);
 print "<html><head><title>$title</title> </head>n<body>nn";
 ## HTML content let use know we sent an email
 print "<h1>$title</h1>n";
 print "<p>A message has been sent from $from to $to";
 print "nn</body></html>";

References
 http://www.bin-co.com/perl/tutorial/
 http://www.cs.cf.ac.uk/Dave/PERL/perl_caller.html
 http://www.java2s.com/Code/Perl/CGI/CatalogCGI.h
tm
 http://cgi-app.org/index.cgi?Examples
 http://perldoc.perl.org/5.14.0/CGI.html
 http://perl.about.com/od/perltutorials/a/perlmysql.ht
m
 http://www.perl.com/pub/2003/10/23/databases.ht
ml
 http://anzer.tripod.com/uwindows.htm
7/5/2013
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126
For any queries, mail:
training.materials@ymail.com
7/5/2013

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