WEB Programming
Introduction to PHP
Lec 1
Mohammed Sultan
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Outlines
• Web Servers
• introduction to PHP
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WEB SERVERS
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What is server?
• A server is a computer or device on a network
that manages network resources.
• Most servers are dedicated. This means that
they perform only one task rather than multiple
tasks on multiprocessing operating systems,
however, a single computer can execute several
programs at once
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What is web server?
• A Web server is a program that generates and
transmits responses to client requests for Web
resources.
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How do Web Servers work?
• Client specifies document at a specific web
address that is desired (specified by a URL)
– Ex: http://www.Aljanad_univ.edu/
• If the document is HTML or text, the server
simply forwards it back to the client
– If it is text, it is shown unaltered in the browser
– If it is HTML it is rendered in the client's browser
• HTML tags are interpreted and result is shown to the user
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How do Web Servers work?
• However, the requested document may be an
executable script, or it may be HTML with an
embedded script
• In these cases, the server executes the script
– If the entire document was a script, the server simply
sends the output back to the client
– If the document had an embedded script, the script
sections are replaced with the output and the
modified document is then sent to the client
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How do Web Servers work?
• Note that the client never sees the server-side
script code
– This is important – typically client should not see
logic / code that the server executes to process
requests
– The server may be accessing files whose names
should not be seen, or preprocessing data that it
does not want the client to see
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Web Site versus Web Server?
• Web site and Web server are different:
– A Web site consists of a collection of Web pages
associated with a particular hostname.
– A Web server is a program to satisfy client
requests for Web resources.
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Types Of Web Servers
1. Apache Web Server
2. IIS Server
3. Xampp Server
4. WAMP Server
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Apache Web Server
• Apache Web server is the most commonly used http
server today. About 80% of all websites and Intranets use
Apache web server to deliver their content to requesting
Browsers.
• Server side programming languages such as PHP, Perl,
Python, Java and many others
• Apache is free software distributed by the Apache
Software Foundation. The Apache Software Foundation
promotes various free and open source advanced Web
technologies.
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Hypertext preprocessing
PHP
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What is PHP?
• PHP is an acronym for "PHP: Hypertext Preprocessor"
• Language developed by Rasmus Lerdorf from the
Apache Group (1994)
• Open Source
– In general, open source refers to any program whose
source code is made available for use or modification.
– Open source software is usually developed as a public
collaboration and made freely available.
• PHP is a HUGE language
• It is a fully functional language
• It has an incredible amount of built-in features
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What is PHP?
• PHP runs on various platforms (Windows,
Linux, Unix, Mac OS X, etc.)
• PHP is compatible with almost all servers used
today (Apache, IIS, etc.)
• PHP supports a wide range of databases
– Ex:Mysql
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History
The PHP version 4.0 was launched in May 2000.
This version includes session handling, output
buffering, a richer cire language and support for
wide variety of web server platforms.
• The PHP 5.0 version released in 2004 with
object oriented programming concept.
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What's new in PHP 7?
• PHP 7 is much faster than the previous popular
stable release (PHP 5.6)
• PHP 7 has improved Error Handling
• PHP 7 supports stricter Type Declarations for
function arguments
• PHP 7 supports new operators (like the spaceship
operator: <=>)
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What Do I Need?
• Find a web host with PHP and MySQL support
• Install a web server on your own PC, and then
install PHP and MySQL
• Set Up PHP on Your Own PC:
– install a web server
– install PHP
– install a database, such as MySQL
Because PHP is free, most web hosts offer PHP
support. 17
What is PHP?
• PHP scripts execute on web server and serve
WebPages to user on request.
• Its primary use is for server-side scripting
– To process HTML forms
– To perform a DB query and pass on results
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What is PHP?
• PHP scripts are often embedded within HTML
documents
• The server processes the HTML document,
executing the PHP segments and substituting
the output within the HTML document
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PHP Program Structure
• PHP, as with many scripting languages, does
not have nearly the same structural
requirements as a language like Java
• A script can be just a few lines of code or a
very large, structured program with classes
and objects
– The complexity depends on the task at hand
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PHP Program Structure
<!DOCTYPE html>
<html>
<body>
<?php
echo "My first PHP script!";
?>
</body>
</html>
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PHP Program Structure
<!DOCTYPE html>
HTML5 Document
<html> HTML root
<head>
<title>Simple PHP Example</title> HTML Head
</head>
<body>
<?php
echo "<p><h1>Output</h1>";
echo "<h2>Output</h2>";
?>
PHP Code
<script language="PHP">
echo "\n<b>More PHP Output</b>\n";
</script>
</body>
</html>
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PHP Program Structure
• If we prefer to separate a PHP code segment
from the rest of our script, we can write it in
another file and include it
– Sometimes it is easier if we "separate" the PHP
code from the straight html
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What is a PHP File?
• PHP files can contain text, HTML, CSS,
JavaScript, and PHP code
• PHP code is executed on the server, and the
result is returned to the browser as plain
HTML
• PHP files have extension ".php"
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Downloading
• The official PHP website (PHP.net) has installation instructions for
PHP:
– www.php.net
– http://php.net/manual/en/install.php
– PHP7
• Download Apache Web Server:
– The latest stable build of Apache http server can be downloaded from
• URLhttp://httpd.apache.org
• Download Mysql :
– https://www.mysql.com ›
– MySQL 8.0
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Any Questions?
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