I recently i launched my project that will generates funny logo of user’s name , i worked around one week to complete this php script generates the funny logo. After one or two weeks users directly linking their logo to my hosting server ,than downloading and hosting on their server.This is called hotlinking where visitors will use directly from our hosted web assets.

So i want stop this hotlinking from hotlinker with htaccess , thanks to apache htaccess rewrite rules .

Here is my small tweak to my htaccess file that prevents hotlinking.

RewriteEngine on
RewriteCond  %{HTTP_REFERER} !^$
RewriteCond  %{HTTP_REFERER} !^http(s)?://(www\.)?maheshchari.com [NC]
RewriteRule  \.(jpg|jpeg|png|gif)$ http://www.maheshchari.com/hotlink.jpg [NC,R,L]

In the above code snippet second and third lines are conditions , if the referrer is blank or maheshchari.com we allow images can be linked , if not we replace that images with hotlink.jpg image.

We can do this for not only images ,we can do it for other media files like mp3, video files, doc files also.

Remember:

You must replace the url to image or any doc file corresponding media type file.

You must allow some websites like facebook,google i.e famaous social networking sites, search engins.

for this you can add as many conditions you want like below

RewriteEngine On
RewriteCond %{HTTP_REFERER} ^http://(.+\.)?google\.com/ [NC,OR]
RewriteCond %{HTTP_REFERER} ^http://(.+\.)?yahoo\.com/ [NC,OR]
RewriteCond %{HTTP_REFERER} ^http://(.+\.)?technorati\.com/ [NC]
 
with this method we can find the hotlinker also by redirecting to our mail sender php script the 
referrer.

generelly when we access the directory on webserver, we get index.html or index.htm or default.asp or index.php.

in some situation we need to change the directory default page to other or specified page. We can set this with htaccess file on server . remember before going to view this tutorial , you have to check htaccess enabled by your web hosting provider.

open your favorite text editor and add following text to it and save as .htacces name .

DirectoryIndex mydirectory.html

So when you open some url like

http://www.yoursite.com/directory/

you will serve the mydirectory.html as default page.

It is best practice to add common file to every php script in our application ,such as libraries cleaning input variables from $_GET,$_POST,$_COOKIE,cleaning or modifying the output of the php script by providing plug in functionality.

We know best example for this many free hosting providers use this settings. they append a advertisement script to our files while it output buffering.

here we learn how to add or remove append or prepend files using htaccess. to continue this tutorial we must have the knowledge of htaccess of apache and basic settings in php.ini

add files to script

this can be achieved by auto_append_file and auto_prepend_file php configuration options.These options can be set in the PHP config, virtual host settings or in a .htaccess file. This post shows how to set these and how to override a setting so no file is appended or prepended.

Example

We have three files append.php, mainscript.php, prepend.php and htaccess file to achieve this.

<?php
//prepend.php
echo "<p>this is the prepended file</p>\n";
?>

<?php
//mainscript.php
echo "<p>this is the main file</p>\n";
?>

<?php
//append.php
echo "<p>this is the appended file</p>\n";
?>

Out put of our mainscript file

<p>this is the prepended file</p>
<p>this is the main file</p>
<p>this is the appended file</p>

Set up php values in htaccess

prepending a file

php_value auto_prepend_file prepend.php

Append a file

php_value auto_prepend_file append.php

Removing or modify existing values

we can override these values for each php file or each directory in our application. we can remove existing auto_append ,auto_prepend values by setting its values to none.

php_value auto_append_file none
php_value auto_prepend_file none

The htaccess gives you the ability to redirect the visitor to different pages if they try to access an invalid page. You can use a custom error page for any type of error as long as you know its number. using custom error page helps lot to increase the performence in Search Engine Optimizaton.

To know detailed http error codes refer to my previous post.to work out this you need to add these htaccess command to your httaccess file and include in your server root folder.

To know how to user htaccess file please refere to my previouse post.

Example: 404 Page Not Found. The layout for this command is :

ErrorDocument errornumber /filename.html

So if you create a page called NotFound.html and you wanted to use it as the 404 error page, the command would be :

ErrorDocument 404 /NotFound.html

If you want to keep all of the error pages in a separate directory, just include the directory name in the file path :

ErrorDocument 404 /errorpages/NotFound.html

The most used error documents are :

400 Bad Request A generic kind of error that people get into by doing some strange stuff with your URL or scripts.

401 Authorization Required When someone tries to enter a protected area without proper authorization.

403 Forbidden When a file with permissions not allowing it to be accessed by the user is requested.

404 Not Found Kinda obvious.

500 Internal Server Error This may help you with internal server errors in any scripts you have running.

There are many others, To view complete http error code see my previous post.

we know that web servers and web client uses mostly common protocol is HTTP, we need use response codes in our application . So i made a simple and breif reference below

Successful Client Requests

200 OK
201 Created
202 Accepted
203 Non-Authorative Information
204 No Content
205 Reset Content
206 Partial Content

Client Request Redirected

300 Multiple Choices
301 Moved Permanently
302 Moved Temporarily
303 See Other
304 Not Modified
305 Use Proxy

Client Request Errors

400 Bad Request
401 Authorization Required
402 Payment Required (not used yet)
403 Forbidden
404 Not Found
405 Method Not Allowed
406 Not Acceptable (encoding)
407 Proxy Authentication Required
408 Request Timed Out
409 Conflicting Request
410 Gone
411 Content Length Required
412 Precondition Failed
413 Request Entity Too Long
414 Request URI Too Long
415 Unsupported Media Type

Server Errors

500 Internal Server Error
501 Not Implemented
502 Bad Gateway
503 Service Unavailable
504 Gateway Timeout
505 HTTP Version Not Supported

We know the impotence of the Search Engine Friendly URLs . To make an application SEF preferable we must have .htaccess permissions and mod_rewrite module enabled.

Here we discuss if apache web server mod_rewrite module enabled or not.

Step1: Open your note pad and pate below code in it and Save as phpinfo.php.

<?php phpinfo(); ?>

Step2: Now preview this page and find the “mod_rewrite” in the column of “Loaded modules”.

Step3: If we found this we enabled mod_rewrite module.

Step4:if we didn’t found ,we can enable it by reading my previous article.

Before enabling this module for SEF URL s ,we must have permission to use .htaccess file .Please read my previous post to enable .htacess.

Before beginning this article ,please back up your apache configuration file httpd.conf file located in apache installation.

Now open with note pad this configuration file and find the below the lin

#LoadModule rewrite_module modules/mod_rewrite.so

Now remove the “#” symbol in the above line,results modified looks below

LoadModule rewrite_module modules/mod_rewrite.so

Now Save the file and restart the apache now mod_rewrite module is enabled.

we know that htaccess permission must on apache web server like making SEF urls, directory permissions..etc.here we discuss about how to check .htaccess enabled.

Before we begin this tutorial, please make sure you make a backup copy of the original httpd.conf apache configuration file located in apache installation folder in case we make a mistake, this way we can always go back to the original configuration file

Now open

httpd.conf

file with note pad and find the below text

<Directory />
    Options FollowSymLinks
    AllowOverride none
    Order deny,allow
    Deny from all
    Satisfy all
</Directory>

Then replace AllowOverride none to AllowOverride All. Modified version looks as below

<Directory />
    Options FollowSymLinks
    AllowOverride all
    Order deny,allow
    Deny from all
    Satisfy all
</Directory>

Above change tells the apache to use .htaccess as per directory bases.
Now we can use .htaccess files .

Remember

Remember while uploading .htaccess file to remote server make sure the file transfer in ASCII mode, generally with windows operating system FTP programs use binary mode.

Generally FTP programs doesn’t display the .htaccess files by default ,we must force the FTP program to show hidden files like .htaccess files.

When you save .htaccess file with note pad it saves as .htaccess.txt .Make sure .htaccess is a file extension not a file name with empty name.

We are familiar with Codeigniter comes with optional SEF URLs, but we use non SEF urls in production or development version.

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2

http://localhost/index.php/helloworld/welcome/
http://localhost/helloworld/welcom/

In the above snippet we know that line 1 is default URL which contains index.php in URl part that used in development version.
Second line is the deployed version SEF URL, generally we need some tweaks with .htaccess and configure stuff.

htaccess

Open note pad and copy and paste below code into that and save it as .htaccess and copy this file into your codeigniters root directory where it was installed.

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DirectoryIndex index.php
RewriteEngine on
RewriteCond $1 !^(index\.php|images|css|js|robots\.txt|favicon\.ico)
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ ./index.php/$1 [L,QSA]

Line 1: set index.php as default directory index instead of index.html

Line 2: Start rewriting engine on

Line 3: start a condition that won’t meet this situation where the request to static resources like images , css, javascript , robot text files

Line 4: make condition user requests a valid request

Line 5: make condition no physical file exists with the given URL

Line 6: if above conditions all met redirect the request to index.php on installation

making changes to config.php file

open the file in the directory system/application/config/config.php make following changes.
Find below line

$config['index_page'] = "index.php";

Replace above line with below code

$config['index_page'] = "";

Now test the new URLs ,it done.

In our real time,we work mostly small websites where limited static files are hosted. So in that case we waste additional money for less than a Mb files. Here we learn simple hack how to add multiple sites to single account using single .htaccess file.

For example, if you are hosting your domain name "maheshchari.com" with us and added a Domain Alias for "mahesh.com", then http://www.maheshchari.com and http://www.mahesh.com would take a visitor to the exact same pages of maheshchari.com website. http://maheshchari.com/somefile.html would bring someone to the exact same page as http://mahesh.com/somefile.html.

Using this method, you can host an additional website within your account for each Domain you add. Or you can point the mahesh.com same as maheshchari.com,So you are adding "A" same for both domains in DNS management .

After that This is a custom configuration requiring a couple extra steps.

After Pointing both domain to same Server IP , then place an .htaccess file in /htdocs/www of the following example format:

RewriteEngine On
RewriteCond %{HTTP_HOST}  mahesh.com$ [NC]
RewriteCond %{REQUEST_URI} !^/mahesh/.*$
RewriteRule ^(.*)$  /mahesh/$1

Then, upload your HTML files maheshchari.com to /htdocs/www/ and your HTML files for mahesh.com to /htdocs/www/mahesh

Remeber you can’t add emails for mahesh.com for that .