php guruji

PHP and MySQL are usually associated with LAMP (Linux, Apache, MySQL, PHP). However, most PHP developer ( including me ) are actually using Windows when developing the PHP application. So this page will only cover the WAMP ( Windows, Apache, MySQL, PHP ). You will learn how to install Apache, PHP, and MySQL under Windows platform.



The first step is to download the packages :

* Apache : www.apache.org
* PHP : www.php.net
* MySQL : www.mysql.com

You should get the latest version of each packages. As for the example in this tutorial i'm using Apache 2.0.50 ( apache_2.0.50-win32-x86-no_ssl.msi ), PHP 4.3.10 ( php-4.3.10-Win32.zip ) and MySQL 4.0.18 ( mysql-4.0.18-win.zip ).

Now let's start the installation process one by one.



Installing Apache

Installing apache is easy if you download the Microsoft Installer ( .msi ) package. Just double click on the icon to run the installation wizard. Click next until you see the Server Information window. You can enter localhost for both the Network Domain and Server Name. As for the administrator's email address you can enter anything you want.

I'm using Windows XP and installed Apache as Service so everytime I start Windows Apache is automatically started.

Install Apache PHP MySQL - Enter Apache server information

Click the Next button and choose Typical installation. Click Next one more time and choose where you want to install Apache ( I installed it in the default location C:\Program Files\Apache Group ). Click the Next button and then the Install button to complete the installation process.

To see if you Apache installation was successful open up you browser and type http://localhost in the address bar. You should see something like this :

Install Apache PHP MySQL - Testing Apache Installation ( thumbnail created using PHP graphics library )



By default Apache's document root is set to htdocs directory. The document root is where you must put all your PHP or HTML files so it will be process by Apache ( and can be seen through a web browser ). Of course you can change it to point to any directory you want. The configuration file for Apache is stored in C:\Program Files\Apache Group\Apache2\conf\httpd.conf ( assuming you installed Apache in C:\Program Files\Apache Group ) . It's just a plain text file so you can use Notepad to edit it.

For example, if you want to put all your PHP or HTML files in C:\www just find this line in the httpd.conf :

DocumentRoot "C:/Program Files/Apache Group/Apache2/htdocs"

and change it to :

DocumentRoot "C:/www"

After making changes to the configuration file you have to restart Apache ( Start > Programs > Apache HTTP Server 2.0.50 > Control Apache Server > Restart ) to see the effect.

Another configuration you may want to change is the directory index. This is the file that Apache will show when you request a directory. As an example if you type http://www.php-mysql-tutorial.com/ without specifying any file the index.php file will be automatically shown.

Suppose you want apache to use index.html, index.php or main.php as the directory index you can modify the DirectoryIndex value like this :

DirectoryIndex index.html index.php main.php

Now whenever you request a directory such as http://localhost/ Apache will try to find the index.html file or if it's not found Apache will use index.php. In case index.php is also not found then main.php will be used.


Installing PHP

First, extract the PHP package ( php-4.3.10-Win32.zip ). I extracted the package in the directory where Apache was installed ( C:\Program Files\Apache Group\Apache2 ). Change the new created directory name to php ( just to make it shorter ). Then copy the file php.ini-dist in PHP directory to you windows directory ( C:\Windows or C:\Winnt depends on where you installed Windows ) and rename the file to php.ini. This is the PHP configuration file and we'll take a look what's in it later on.

Next, move the php4ts.dll file from the newly created php directory into the sapi subdirectory. Quoting from php installation file you can also place php4ts.dll in other places such as :

* In the directory where apache.exe is start from ( C:\Program Files\Apache Group\Apache2 \bin)
* In your %SYSTEMROOT%\System32, %SYSTEMROOT%\system and %SYSTEMROOT% directory.
Note: %SYSTEMROOT%\System32 only applies to Windows NT/2000/XP)
* In your whole %PATH%

Side Note : Thanks to Shannon Tang for pointing this out



Modifying Apache Configuration

Apache doesn't know that you just install PHP. We need to tell Apache about PHP and where to find it. Open the Apache configuration file in C:\Program Files\Apache Group\Apache2\conf\httpd.conf and add the following three lines :

LoadModule php4_module php/sapi/php4apache2.dll
AddType application/x-httpd-php .php
AddType application/x-httpd-php-source .phps

The first line tells Apache where to load the dll required to execute PHP and the second line means that every file that ends with .php should be processed as a PHP file. You can actually change it to anything you want like .html or even .asp! The third line is added so that you can view your php file source code in the browser window. You will see what this mean when you browse this tutorial and click the link to the example's source code like this one.

Now restart Apache for the changes to take effect ( Start > Programs > Apache HTTP Server 2.0.50 > Control Apache Server > Restart ) . To check if everything is okay create a new file, name it as test.php and put it in document root directory ( C:\Program Files\Apache Group\Apache2\htdocs ). The content of this file is shown below.


phpinfo();
?>

phpinfo() is the infamous PHP function which will spit out all kinds of stuff about PHP and your server configuration. Type http://localhost/test.php on your browser's address bar and if everything works well you should see something like this :


Installing MySQL

First extract the package ( mysql-4.0.18-win.zip ) to a temporary directory, then run setup.exe. Keep clicking the next button to complete the installation. By default MySQL will be installed in C:\mysql.

Open a DOS window and go to C:\mysql\bin and then run mysqld-nt --console , you should see some messages like these :
C:\mysql\bin>mysqld-nt --console
InnoDB: The first specified data file .\ibdata1 did not exist:
InnoDB: a new database to be created!
040807 10:54:09 InnoDB: Setting file .\ibdata1 size to 10 MB
InnoDB: Database physically writes the file full: wait...
040807 10:54:11 InnoDB: Log file .\ib_logfile0 did not exist: new to be created

InnoDB: Setting log file .\ib_logfile0 size to 5 MB
InnoDB: Database physically writes the file full: wait...
040807 10:54:12 InnoDB: Log file .\ib_logfile1 did not exist: new to be created

InnoDB: Setting log file .\ib_logfile1 size to 5 MB
InnoDB: Database physically writes the file full: wait...
InnoDB: Doublewrite buffer not found: creating new
InnoDB: Doublewrite buffer created
InnoDB: Creating foreign key constraint system tables
InnoDB: Foreign key constraint system tables created
040807 10:54:31 InnoDB: Started
mysqld-nt: ready for connections.
Version: '4.0.18-nt' socket: '' port: 3306

Now open another DOS window and type C:\mysql\bin\mysql

if your installation is successful you will see the MySQL client running :


C:\mysql\bin>mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1 to server version: 4.0.18-nt

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql>
Type exit on the mysql> prompt to quit the MySQL client.

Now let's install MySQL as a Service. The process is simple just type mysqld-nt --install to install the service and net start mysql to run the service. But make sure to shutdown the server first using mysqladmin -u root shutdown



C:\mysql\bin>mysqladmin -u root shutdown

C:\mysql\bin>mysqld-nt --install
Service successfully installed.

C:\mysql\bin>net start mysql

The MySQL service was started successfully.

C:\mysql\bin>mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1 to server version: 4.0.18-nt

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql>


Modifying PHP Configuration File ( php.ini )

PHP stores all kinds of configuration in a file called php.ini.You can find this file in the directory where you installed PHP. Sometimes you will need to modify this file for example to use a PHP extension. I won't explain each and every configuration available just the ones that often need modification or special attention.

Some of the configurations are :

1. register_globals
2. error_reporting and display_errors
3. extension and extension_path
4. session.save_path
5. max_execution_time

register_globals

Before PHP 4.2.0 the default value for this configuration is On and after 4.2.0 the default value is Off. The reason for this change is because it is so easy to write insecure code with this value on. So make sure that this value is Off in php.ini.
error_reporting and display_errors

Set the value to error_reporting = E_ALL during development but after production set the value to error_reporting = E_NONE .

The reason to use E_ALL during development is so you can catch most of the nasty bugs in your code. PHP will complain just about any errors you make and spit out all kinds of warning ( for example if you're trying to use an uninitialized variable ).

However, after production you should change the value to E_NONE so PHP will keep quiet even if there's an error in your code. This way the user won't have to see all kinds of PHP error message when running the script.

One important thing to note is that you will also need to set the value of display_erros to On. Even if you set error_reporting = E_ALL you will not get any error message ( no matter how buggy our script is ) unless display_errors is set to On.
extension and extension_path

PHP4 comes with about 51 extensions such as GD library ( for graphics creation and manipulation ), CURL, PostgreSQL support etc. These extensions are not turned on automatically. If you need to use the extension, first you need to specify the location of the extensions and then uncomment the extension you want.

The value of extension_path must be set to the directory where the extension is installed which is PHP_INSTALL_DIR/extensions, with PHP_INSTALL_DIR is the directory where you install PHP. For example I installed PHP in C:\Program Files\Apache Group\Apache2\php so the extensions path is :

extension_path = C:/Program Files/Apache Group/Apache2/php/extensions/

Don't forget to add that last slash or it won't work

After specifying the extension_path you will need to uncomment the extension you want to use. In php.ini a comment is started using a semicolon (;). As an example if you want to use GD library then you must remove the semicolon at the beginning of ;extension=php_gd2.dll to extension=php_gd2.dll
session.save_path

This configuration tells PHP where to save the session data. You will need to set this value to an existing directory or you will not be able to use session. In Windows you can set this value as session.save_path = c:/windows/temp/
max_execution_time

The default value for max_execution_time is 30 ( seconds ). But for some scripts 30 seconds is just not enough to complete it's task. For example a database backup script may need more time to save a huge database.

If you think your script will need extra time to finish the job you can set this to a higher value. For example to set the maximun script execution time to 15 minutes ( 900 seconds ) you can modify the configuration as max_execution_time = 900

PHP have a convenient function to modify PHP configuration in runtime, ini_set(). Setting PHP configuration using this function will not make the effect permanent. It last only until the script ends.

Mod_rewrite is an Apache module that can be accessed from .htaccess files to perform all kinds of complicated URL manipulation. A few months ago I posted an article called Beat Your Website into Submission with .htaccess explaining how to use several .htaccess features to do helpful tricks; but I didn't really touch on mod_rewrite or RewriteRule. Since then I was involved in a project that required extensive use of mod_rewrite and I've come to truly appreciate its power and usefulness. The main mod_rewrite function, RewriteRule, is powered by regular expressions. Regular expressions are used to search blocks of text for specific patterns. I barely have enough room in this article to scratch the surface of regular expressions; so if you need more detail in that area I recommend this website. For the purposes of this tutorial, though, I'll be sticking to commonly used URL rewriting tasks.
The Setup

Before you start messing with RewriteRule, you need to make sure your .htaccess file is ready for tinkering. The first two lines in the sample code below activate the mod_rewrite module. The third line prevents more than ten redirects per browser call. If this line is left out, a misplaced "+" or "." in your regular expression could create an infinite loop that will grind your server to a halt. Unfortunately, I didn't discover this little snippet until I was about half way through my project. But you can avoid my mistake. Put this at the top of your .htaccess file.

Options +FollowSymlinks
RewriteEngine on
RewriteOptions MaxRedirects=10
RewriteRule Basics

With mod_rewrite there are a number of powerful functions at your disposal. You saw RewriteEngine and RewriteOptions in the first section. These functions set the stage for the star of the show—RewriteRule. RewriteRule can compare a URL against just able any criteria and rewrite the url according to your specifications. As I mentioned, RewriteRule uses regular expressions to search a URL for character patterns. Here's a helpful example that matches any URL that ends with .htm and redirects it to the same file with the extension .php. This would be helpful if you were moving your website from a static HTML site to a PHP driven site.

Options +FollowSymlinks
RewriteEngine on
RewriteOptions MaxRedirects=10
RewriteRule ^(.*).htm$ $1.php [NC]

On the RewriteRule line the "^" denotes the beginning of the regular expression and the "$" denotes the end. The [NC] at the end of the RewriteRule line keeps the command from being case-sensitive.
Redirecting the Right Way

Lots of web designers know that .htaccess can be used to redirect a browser to another page. But very few know much beyond the absolute basics and even fewer know the right code to send with the redirect. For search engine purposes it's important that you don't get these codes mixed up. All of the redirect codes are in the 300 range. W3.org has an extensive guide to redirect codes but here are the ones most commonly used:

301 Permanently Moved

Use this code when you have content that has permanently moved to a new URL.

302 Found

Use this code when you have content that is temporarily residing at a different URL.

307

The same as 302 with some additional options

Redirecting Your Website to a New Domain

Whenever you change the domain of your website, it's important to redirect properly to the new domain name to avoid a double content penalty from search engines. For example, if you simply park your old domain on top of your new domain, some search engines will see this as double content. Here's a RewriteRule that will redirect correctly with a 301 (Permanently Moved) code.

Options +FollowSymlinks
RewriteEngine on
RewriteOptions MaxRedirects=10
RewriteRule ^(.+).php$ http://new_domain.com/$1.php [R=301,NC]

Sometime, when you move a website to a new domain, the names of the pages don't necessarily stay the same. To redirect a page on one domain to a page with a different name on a new domain, you would add an additional ReWriteRule line to your .htaccess file that would look like this:
RewriteRule ^old_page.php$ http://new_domain.com/new_page.php [R=301,NC]
Creating Dynamic Directories in the Root of Your Site
The RewriteRule will parse the URL request as it comes in from the browser...

Lots of social sites such as MySpace.com allow you to access certain personal pages in a url format that looks like this: myspace.com/myusername. Obviously, MySpace doesn't manually create a new directory every time a new member joins. Achieving this effect is simple with RewriteRule. But in order to make this example work, all of the pages in your website will need to be moved into a new directory in the root of your site (eg. mydomain.com/pages). There should be no pages in the root directory of the site at all. The RewriteRule will parse the URL request as it comes in from the browser and redirect accordingly. The code below will search an incoming URL for a simple user name that is between 6 and 12 characters long. If no user name is present, the browser will be redirected to the index.php page in the "pages" directory. A second .htaccess file (listed after the one below) should be created and uploaded into the "pages" directory. This .htaccess file will block the RewriteRules from the first .htaccess files.

Options +FollowSymlinks
RewriteEngine on
RewriteOptions MaxRedirects=10

RewriteRule ^(.{6,12})$ http://mydomain.com/pages/users/index.php?user_name=$1 [NC]
RewriteRule ^$ http://mydomain.com/pages/index.php [R=301,NC]

The first RewriteRule redirects any URL with a six to twelve character user name to the the user page and passes the user name in as a variable. The second RewriteRule checks for incoming URLs that have no user name (ie. http://mydomain.com/). When this occurs, the visitor is redirected to the home page in the "pages" directory. This is the .htaccess file that should be placed in the "pages" directory.

Options +FollowSymlinks
RewriteEngine off
Beautifying and Optimizing Your URLs

Long URLs with multiple embedded variables are ugly, awkward to copy and paste, and difficult for search engines to index. With RewriteRule, though, you can turn a URL that looks like this: http://mydomain.com/blog.php?category=news&month=05&year=2008 into this: http://mydomain.com/news/05/2008. Much more attractive, right? Here's the code:

Options +FollowSymlinks
RewriteEngine on
RewriteOptions MaxRedirects=10

RewriteRule ^blog/([^/]+)/([^/]+)$ blog.php?category=$1&article_id=$2 [NC]

In this example, matches found in parenthesis are stored in successive variables starting with $1 and going up. So, for example the URL http://mydomain.com/blog/news/4450 would be rewritten http://mydomain.com/blog.php?category_id=news&article_id=4450.