Installation of PHP

PHP with IMAP support

A number of very good webmail applications, like Squirrelmail make use of the Internet Message Access Protocol or IMAP, so we'll need to download this and install it before compiling and installing PHP. You can find IMAP at the University of Washington's FTP site. At the time of this writing the url is: ftp://ftp.cac.washington.edu/imap/ and the version is imap-2004g. After downloading, untar the package in the apache_install directory and issue this command:

./make slx

If you've done everything for installing Apache correctly up to this point, you should have no problems. This creates the necessary libraries and header files that PHP will need to have IMAP support.

Other Support for PHP

There are a lot of different options that we can use when configuring PHP for installation. You can see these options by entering the php5 source code directory and typing:

./configure --help

For this lesson, along with IMAP support that we mentioned before, we'll be adding SSL support (from our previous installation of OpenSSL) MySQL, GD and XML support. GD is a graphics library for creating images on the fly. This comes in handy for creating graphs of data particularly, but there are a lot of other uses. For example, in web one application I created, I used GD to produce an human-only readable image to keep robots from signing up dummy accounts. This is just one use of GD. XML, on the other hand, is slowly but surely becoming the markup language of choice for web publishing. It's an extremely versatile format that lets you set your own criteria for your documents. Our installed version of PHP will have support for parsing XML documents with XSL style sheets. If you're not familiar with the use of either XML or XSL, I encourage you to check out the specifications at the World Wide Web Consortium: http://www.w3c.org/. One of the advantages of using PHP5 is the excellent XML support designed into it. It's well worth our while to use it.

Apart from the MySQL client and server, you need to make sure the necessary GD and XML packages are installed on your system. Since we're using Fedora Core for this tutorial, we made sure the following packages were installed:

• gd

• gd-devel

• gd-progs

• libgd2

• libjpeg-devel

• freetype-devel

• libpng

• libpng-devel

• libxslt

• libxslt-devel

If they're not, you can either use 'yum' to install them or pick up the RPMs and install them by hand. If you're using a distribution other than Fedora Core, then use that distribution's package system to make sure you have them and if not, install them.

We can now issue the configure command to get our PHP package ready for compiling and installing:

./configure --with-mysql --with-gd=/usr \
--with-imap=../imap-2004g/ \
--with-openssl=/usr \
--with-apxs=/usr/local/apache/bin/apxs \
--with-xml --with-xsl=/usr --enable-soap \
 | tee config_php_YYYYMMDD_HHMM

Again, I piped the output to another file. This will come in handy if you get error messages. You'll see that the above configure command includes all of the support we want. At the end, I've enabled 'SOAP' support as well. This is another use of XML to share information across the web. It is currently being used by Amazon to a great extent in their affiliate bookseller program. All of these options will give us a complete and robust PHP engine for web development.

When it's finished configuring, issue the command: make. Then, finally, as root, issue the command: make install. This will have installed PHP for use by Apache. This should also have modified Apache's httpd.conf to include a few new lines. To make sure, have a look at the file in /usr/local/apache/conf/ and look for the following lines:

LoadModule php5_module        libexec/libphp5.so

and

AddModule mod_php5.c

and

AddType application/x-httpd-php .php .phtml
AddType application/x-httpd-php-source .phps

If your httpd.conf has these lines then you should do one more thing before starting or re-starting Apache. Copy the file php.ini-dist in your source directory to /usr/local/lib/php.ini (thus renaming it as well). This file can be changed to effect PHP's behavior with respect to certain things. It's a good idea to peruse this file and familiarize yourself with what certain settings do.

Let's Try an Example

Now, let's create a very short script to see if all of the options you wanted are in place. Go to /usr/local/apache/htdocs/ on the server and create this script with 'vi' or your favorite text editor:

<?php 

phpinfo(); 

?>

Name it whatever you like (info.php, for example) and point your web browser to it. You should see the PHP information page, starting with the PHP logo and displaying information about your PHP set up in purple and gray tables. Browsing down the tables, you should see information on the modules that you compiled into it (XML, GD, etc). If you're seeing this, then you got it right. You're now ready for web development with PHP on your server.

Expect Some Changes

If you've programmed with PHP before, but with versions 3 or 4, you may find that some of your scripts are broken. PHP5 has added certain features that have to do with security mainly and this may effect your scripts. Some changes to php.ini may get your scripts working again, but then you may have coding practices that are not recommended from a security standpoint. PHP5 may be the opportunity that you need to make changes to your scripts and web applications to make them more secure.

One problem I ran across is the handling of HTML form variables. I started programming when PHP3 was the only version. PHP4 was a major re-write of PHP3 and PHP5 is again another major re-write. Most should work, but if you run into problems, it shouldn't be too difficult to get around them. Consulting the PHP5 documentation along with with web forums will turn up creative solutions to these problems.