PHP Exercise 1

Basic PHP syntax

 

  1. The first thing you need to understand is basic HTML and how PHP works with HTML. The first useful thing to do is create a very simple PHP page that simply prints out some HTML code to give you a web page.
  2. Throughout this tutorial, you can either use the terminal based vi program or you can open up a KDE text editor similar to Windows notepad by clicking on the red hat in the lower left hand corner of your screen and going to Accessories > More Accessories > Text Editor
  3. Create a file called new_php_file.php in the /var/www/html directory and open a text editor in a terminal window by doing the following:

 

shell > cd /var/www/html

shell > vi new_php_file.php

 

  1. Then hit i  (if you created the file in vi) on the keyboard and type the following:

 

<html>

<head>

<title>PHP Test</title>

</head>

<body>

<?php echo "<p>Hello World<p>"; ?>

</body>

</html>

 

  1. When you are done entering this text, hit the ESC key on the keyboard followed by :wq which means write and quit (only if you use vi ). To view your new file, open your web browser and type in http://localhost/new_php_file.php in the address bar. You could accomplish the same thing by making a file called new_html_file.html and insert the following lines:

 

<html>

<head>

<title>PHP Test</title>

</head>

<body>

<p>Hello World<p>

</body>

</html>

 

  1. So after comparing the two versions we see that the php section started with <?php and ended with ?>. The echo""; function in php printed out HTML code to the browser.
  2. Figure 6.1 shows a screen shot of the output from the new_php_file.php

 


Figure 6.1

 

  1. If you created both of these files, you should seem the same thing on the screen when viewing both files. If your .php file doesn't work correctly, make sure you followed the Apache installation proceedures correctly.
  2. Next let's look at another built in PHP function called phpinfo(). This function will tell us everything we need to know about our installed PHP interpreter. Go back to your terminal window and type

 

shell > vi new_php_file.php

 

10.After you open the file, replace the following line:

 

<?php echo "<p>Hello World<p>"; ?>

 

with the following:

 

<?php

echo "<p>Hello World</p><br>";

phpinfo();

?>

 

11.                     Be sure to hit ESC and then :w to save the file.

12.                     This will print out to the screen a huge amount of information regarding the PHP interpreter, your Apache server, and other components of your machine.

13.                     Note that PHP doesn't particularly care about "white space", new lines, tabs, etc. Certain functions in PHP do have "white space" requirements.

 

 

On Your Own Exercise 1

 

  1. Create an .html file that displays information about yourself, including name, age, and favorite color. Then copy and paste the HTML into a .php file and use the echo() function to display your HTML.