If you plan to install PHP on Linux or any other variant of Unix, then here is the list of prerequisites:
The PHP source distribution PHP
The latest Apache source distribution APACHE
A working PHP-supported database, if you plan to use one ( For example MySQL, Oracle etc. )
Any other supported software to which PHP must connect (mail server, BCMath package,JDK, and so forth)
An ANSI C compiler
Gnu make utility - you can freely download it at GNU
Now here are the steps to install Apache and PHP5 on your Linux or Unix machine. If your PHP or Apache versions are different then please take care accordingly.
gunzip -c apache_1.3.x.tar.gz
tar -xvf apache_1.3.x.tar
./configure --prefix=/usr/local/apache --enable-so
gunzip -c php-5.x.tar.gz
tar -xvf php-5.x.tar
./configure --with-apxs=/usr/sbin/apxs --with-mysql=/usr/bin/mysql
cp php.ini-dist /usr/local/lib/php.ini
Tell your Apache server where you want to serve files from, and what extension(s) you want to identify PHP files A .php is the standard, but you can use .html, .phtml, or whatever you want.
Go to your HTTP configuration files (/usr/local/apache/conf or whatever your path is)
Open httpd.conf with a text editor.
Search for the word DocumentRoot (which should appear twice), and change both paths to the directory you want to serve files out of (in our case, /home/httpd). We recommend a home directory rather than the default /usr/local/apache/htdocs because it is more secure, but it doesn.t have to be in a home directory. You will keep all your PHP files in this directory.
Add at least one PHP extension directive, as shown in the first line of code that follows. In the second line, we.ve also added a second handler to have all HTML files parsed as PHP
AddType application/x-httpd-php .php
AddType application/x-httpd-php .html
chmod 755 /home/httpd/html/php
Open a text editor. Type: <?php phpinfo(); ?>. Save this file in your Web server's document root as info.php.
Start any Web browser and browse the file.you must always use an HTTP request (http://www.testdomain.com/info.php or
http://localhost/info.php or http://127.0.0.1/info.php) rather than a filename (/home/httpd/info.php) for the file to be parsed correctly
You should see a long table of information about your new PHP installation message Congratulations!