DSA: PHP

PHP in CEMS

The current version in CEMS is PHP5.

There are three servers with slighly different PHP configurations.

www.cems.uwe.ac.uk - a PHP script will run either on web02 for students or web03 for staff. PHP on these servers has error reporting turned off. For students, www is only accessible if a request has been approved to permit access.
isa.cems.uwe.ac.uk - error reporting is turned on. You should use this server for all development. isa is only available within UWE
stocks.cems.uwe.ac.uk is an older server and runs PHP4

You can check the PHP configuration: isa, www, stocks

Hints

Put all php scripts in a suitable subdirectory of your public_html account on the UNIX server (in the nas folder)
To execute a php script, use a URL of the form

Use the 'isa' host for all development.
You need a line editor like PFE32 so that when an error references a line number, you can find that line in the editor. (we need a better editor - suggestions?)
Beware of the slight time lag between editing a script via Windows and the same changed script being executed on the relevant UNIX server.
Use the $_REQUEST array to access both get and post variables. Use method="get" when testing - it's much easier to detect errors if you can see the values being passed from the browser on the command line. You can also bookmark a URL so a test can be repreated without having to enter the data again. You will also need to use 'get' when a deep link is created, for example in the Album code to fetch a a JPEG.
You can get a php script to display nicely using a suffix of .phps. This can help spot missing quotes or brackets. In my examples I create a symbolic link in Unix to the .php file itself. Beware of exposing passwords to your MySQL account if you do this - place connection details in a separate file which can be placed above the web accessible pages in public_html.

Links

Books

Larry Ullman, PHP and MySQL for Dynamic Web Sites, Peachpit Press ISBN 0321336577
Luke Welling and Laura Thomson, PHP and MySQL Web Development, Sams Publishing. ISBN 0672326728
Leon Atkinson, Core PHP Programming, Prentice Hall , 2001

DSA