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Module 1Introduction to PHP

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Objectives Objectives

What is PHP?What is PHP? How does a PHP script work with a How does a PHP script work with a

Web Browser and a Web Server?Web Browser and a Web Server? What software and components you What software and components you

need to get started with PHP?need to get started with PHP?

To create and run a simple PHP scriptTo create and run a simple PHP script

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What Is PHP?What Is PHP?

PHP, PHP Hypertext PreprocessorPHP, PHP Hypertext Preprocessor Server-side scripting languages for creating Server-side scripting languages for creating

dynamic web pagesdynamic web pages

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PHP advantagesPHP advantages

Advantages of Using PHP to enhance Web Advantages of Using PHP to enhance Web

pages:pages:

Easy to useEasy to use

Simpler than PerlSimpler than Perl Open sourceOpen source Multiple platform.Multiple platform.

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How PHP Pages are Accessed How PHP Pages are Accessed and Interpretedand Interpreted

Client: Web browser Web server

1.Form submitted with a submit button

2.----- Action sends a request to the php file in server

3. Receive the request, find the file,

and read it

4. Execute the PHP commands

5. Send the results back

6. ---- results returned as HTML file

7. Web browser renders the HTML file, displaying the results

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Getting Started with PHPGetting Started with PHP

To develop and publish PHP scripts you need: To develop and publish PHP scripts you need:

A Web server with PHP built into itA Web server with PHP built into it A client machine with a basic text editor and A client machine with a basic text editor and

Internet connectionInternet connection FTP or Telnet softwareFTP or Telnet software

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WHH NoteWHH Note

This means that a browser e.g. IE or This means that a browser e.g. IE or Firefox on the client computer will not Firefox on the client computer will not recognize or render a file with recognize or render a file with extension .phpextension .php

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Getting Started with PHPGetting Started with PHP

For class demos:For class demos:

Laptop contains a server and a browser environmentLaptop contains a server and a browser environment

Web server is WAMPserverWeb server is WAMPserver

Windows Apache, MySQL, PHPWindows Apache, MySQL, PHP

Client machine: PC, XP, editors, browsersClient machine: PC, XP, editors, browsers

Internet connection not neededInternet connection not needed Use copy and paste to transfer the scriptsUse copy and paste to transfer the scripts

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Exploring the Basic PHP Exploring the Basic PHP Development ProcessDevelopment Process

The basic steps you can use to develop and The basic steps you can use to develop and

publish PHP pages are:publish PHP pages are:

1. Create a PHP script file and save it to a local disk1. Create a PHP script file and save it to a local disk

2. Use FTP to copy the file to the server2. Use FTP to copy the file to the server

3. Access your file via URL using a browser3. Access your file via URL using a browser• IE, Netscape, Opera, etc.IE, Netscape, Opera, etc.

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Check PHP installationCheck PHP installation

Create a simple PHP script, called Create a simple PHP script, called checkphp.phpcheckphp.php The PHP script starts with a <?php tag and The PHP script starts with a <?php tag and

ends with ?>ends with ?> Between these tags is a single PHP statement: Between these tags is a single PHP statement:

phpinfo()phpinfo() Copy the file to a directory of serverCopy the file to a directory of server

For WAMP: wamp/wwwFor WAMP: wamp/www Access the file with a browserAccess the file with a browser http://localhost/checkphp.phphttp://localhost/checkphp.php

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Creating a PHP Script FileCreating a PHP Script File

Create a simple PHP script, called Create a simple PHP script, called welcome.phpwelcome.php The PHP script starts with a <?php tag and The PHP script starts with a <?php tag and

ends with ?>ends with ?> Between these tags is a single PHP print Between these tags is a single PHP print

statementstatement Copy the file to C:\wamp\wwwCopy the file to C:\wamp\www Access the file with Access the file with

http://127.0.0.1/welcome.phphttp://127.0.0.1/welcome.php demodemo

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Alternative PHP DelimitersAlternative PHP Delimiters You can alternatively start your PHP scripts You can alternatively start your PHP scripts

with the <script> tag as follows:with the <script> tag as follows:<script language="PHP"><script language="PHP">

print ("A simple initial script");print ("A simple initial script");

</script></script>

If If short_open_tagshort_open_tag enabled in its configuration enabled in its configuration file (php.ini), you can use <? and ?>.file (php.ini), you can use <? and ?>.

If asp_tags is enabled in the PHP If asp_tags is enabled in the PHP configuration file, you can use <% and %> configuration file, you can use <% and %> as delimiters.as delimiters.

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Copying Files To A Web Copying Files To A Web Server with FTPServer with FTP

1. Connect to the Internet and start FTP. 1. Connect to the Internet and start FTP.

2. Connect to your Web server with FTP. 2. Connect to your Web server with FTP.

3. Copy files3. Copy files

to the Web to the Web

server.server.

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Accessing Your File Using a Accessing Your File Using a BrowserBrowser

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Proper SyntaxProper Syntax

If you have a If you have a syntax errorsyntax error then you have then you have written one or more PHP statements that are written one or more PHP statements that are grammatically incorrect in the PHP language.grammatically incorrect in the PHP language.

The The printprint statement syntax: statement syntax:

print ( "Your message to print" );

Enclose messagein quotation

marks

Message to Output

End in asemi-colon

Parenthesis areoptional

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If syntax is wrongIf syntax is wrong

<?php<?php print ( "Welcome to PHP, CS346 class!);print ( "Welcome to PHP, CS346 class!);?>?>

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A Little About PHP's SyntaxA Little About PHP's Syntax

Some PHP Syntax Issues:Some PHP Syntax Issues: Be careful to use quotation marks, parentheses, and Be careful to use quotation marks, parentheses, and

brackets in brackets in pairspairs.. Most PHP commands end with a semicolon (;).Most PHP commands end with a semicolon (;). Be careful of case. Be careful of case. PHP ignores blank spaces.PHP ignores blank spaces.

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Embedding PHP Statements Within Embedding PHP Statements Within HTML DocumentsHTML Documents

One way to use PHP is to embed PHP scripts One way to use PHP is to embed PHP scripts within HTML tags in an HTML document. within HTML tags in an HTML document.

Save the file with extension phpSave the file with extension php

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1.1. <html><html>2.2. <head> <head> 3.3. <title>HTML With PHP Embedded</title> </head><title>HTML With PHP Embedded</title> </head>4.4. <body> <body> 5.5. <font size=5 color=”blue”>Welcome To My <font size=5 color=”blue”>Welcome To My Page</font>Page</font>6.6. <?php<?php7.7. print ("<br> Using PHP is not hard<br>"); print ("<br> Using PHP is not hard<br>");8.8. ?>?>9.9. and you can learn to use it quickly! and you can learn to use it quickly! 10. </body></html>10. </body></html>

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When embedded1.php is accessedWhen embedded1.php is accessed

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Using Backslash (\) to Generate Using Backslash (\) to Generate HTML Tags with print()HTML Tags with print()

Sometimes you want to output an HTML tag Sometimes you want to output an HTML tag that also requires double quotation marks.that also requires double quotation marks. Use the backslash (“\”) character to signal that the Use the backslash (“\”) character to signal that the

double quotation marks themselves should bedouble quotation marks themselves should be

output:output:

print ("<font color=\"blue\">");print ("<font color=\"blue\">"); The above statement would output:The above statement would output: <font color="blue"><font color="blue">

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Using Comments with Using Comments with PHP ScriptsPHP Scripts

Comments enable you to include Comments enable you to include descriptive text along with the PHP descriptive text along with the PHP script.script. Comment lines are ignored when the script Comment lines are ignored when the script

runs; they do not slow down the run-time.runs; they do not slow down the run-time. Comments have two common uses.Comments have two common uses.

• Describe the overall script purpose.Describe the overall script purpose.• Describe particularly tricky script lines.Describe particularly tricky script lines.

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Using Comments with PHP ScriptsUsing Comments with PHP Scripts Comment Syntax - Use // standaloneComment Syntax - Use // standalone

<?php<?php// This is a comment// This is a comment?>?>

Can be placed on Same line as a Can be placed on Same line as a statement:statement:<?php<?phpprint ("A simple initial script"); print ("A simple initial script"); //Output a line//Output a line?>?>

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Example Script with CommentsExample Script with Comments

1. <html> <head>1. <html> <head>

2. <title> Generating HTML From PHP</title> </head>2. <title> Generating HTML From PHP</title> </head>

3. <body> <h1> Generating HTML From PHP</h1>3. <body> <h1> Generating HTML From PHP</h1>

4. <?php4. <?php

5. //5. //

6. // Example script to output HTML tags6. // Example script to output HTML tags

7. //7. //

8. print ("Using PHP has <i>some advantages:</i>");8. print ("Using PHP has <i>some advantages:</i>");

9. print ("<ul><li>Speed</li><li>Ease of use</li>9. print ("<ul><li>Speed</li><li>Ease of use</li>

<li>Functionality</li></ul>"); //Output bullet list<li>Functionality</li></ul>"); //Output bullet list

10. print ("</body></html>");10. print ("</body></html>");

11. ?>11. ?>

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Alternative Comment SyntaxAlternative Comment Syntax

PHP allows a couple of additional ways to PHP allows a couple of additional ways to create comments.create comments.<?php<?phpphpinfo(); # This is a built-in functionphpinfo(); # This is a built-in function?>?>

Multiple line comments.Multiple line comments. <?php<?php

/*/*A script that gets information about theA script that gets information about thePHP version being used.PHP version being used.*/*/<? phpinfo(); ?><? phpinfo(); ?>

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SummarySummary

HTML pages are static and cannot interact with HTML pages are static and cannot interact with usersusers

PHP is a free, open source technology that PHP is a free, open source technology that enables documents to generate dynamic contentenables documents to generate dynamic content

PHP script has the extension of .phpPHP script has the extension of .php PHP script may be standalone orPHP script may be standalone or Can be embedded in an HTML documentCan be embedded in an HTML document

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SummarySummary

Resources needed:Resources needed: Web server with built-in PHPWeb server with built-in PHP a client machine with a basic text editor, a client machine with a basic text editor,

browser, and internet connectionsbrowser, and internet connections FTP or Telnet software to send the script to FTP or Telnet software to send the script to

the serverthe server

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SummarySummary

PHP script process: PHP script process: write the PHP script filewrite the PHP script file copy the script file to the Web servercopy the script file to the Web server access the file with a Web browser access the file with a Web browser

Comments can be proceeded with Comments can be proceeded with two forward slashes (//) two forward slashes (//) or # or # or enclosed in /* and */or enclosed in /* and */