Apache htaccess
htaccess is a configuration file that begins with a period (.) that is read by the web-server first before any other content files and sets the features and rules as to how the server will process any other files or directives within the folder that the .htaccess file is located.
The .htaccess file can be used to redirection, modifying directory order rules, rewriting complex urls so they appear more human or search engine friendly, set access rules to make areas or files password protected or accessible from only select ip addresses.
htaccess is for advanced webmasters and developers and if improperly set can cause looping that will cause the firewall to block your website so caution should always be excercised.
htaccess Cheatsheet
Here is a simple cheatsheet for the .htaccess file:
Enable Directory Browsing
Options +Indexes
## block a few types of files from showing
IndexIgnore *.wmv *.mp4 *.avi
Disable Directory Browsing
Options All -Indexes
Customize Error Messages
ErrorDocument 403 /forbidden.html
ErrorDocument 404 /notfound.html
ErrorDocument 500 /servererror.html
Get SSI working with HTML/SHTML
AddType text/html .html
AddType text/html .shtml
AddHandler server-parsed .html
AddHandler server-parsed .shtml
# AddHandler server-parsed .htm
Change Default Page (order is followed!)
DirectoryIndex myhome.htm index.htm index.php
Block Users from accessing the site
<limit GET POST PUT>
order deny,allow
deny from 202.54.122.33
deny from 8.70.44.53
deny from .spammers.com
allow from all
</limit>
Allow only LAN users
order deny,allow
deny from all
allow from 192.168.0.0/24
Redirect Visitors to New Page/Directory
Redirect oldpage.html http://www.domainname.com/newpage.html
Redirect /olddir http://www.domainname.com/newdir/
Block site from specific referrers
RewriteEngine on
RewriteCond %{HTTP_REFERER} site-to-block\.com [NC]
RewriteCond %{HTTP_REFERER} site-to-block-2\.com [NC]
RewriteRule .* - [F]
Block Hot Linking/Bandwidth hogging
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www\.)?mydomain.com/.*$ [NC]
RewriteRule \.(gif|jpg)$ - [F]
Want to show a “Stealing is Bad” message too?
Add this below the Hot Link Blocking code:
RewriteRule \.(gif|jpg)$ http://www.mydomain.com/dontsteal.gif [R,L]
Stop .htaccess (or any other file) from being viewed
<files file-name>
order allow,deny
deny from all
</files>
Avoid the 500 Error
# Avoid 500 error by passing charset
AddDefaultCharset utf-8
Grant CGI Access in a directory
Options +ExecCGI
AddHandler cgi-script cgi pl
# To enable all scripts in a directory use the following
# SetHandler cgi-script
Password Protecting Directories
Use the build in cPanel Password Protected Directories
Change Script Extensions
AddType application/x-httpd-php .gne
gne will now be treated as PHP files! Similarly, x-httpd-cgi for CGI files, etc.
Use MD5 Digests
Performance may take a hit but if thats not a problem, this is a nice option to turn on.
ContentDigest On
The CheckSpelling Directive
From Jens Meiert: CheckSpelling corrects simple spelling errors (for example, if someone forgets a letter or if any character is just wrong). Just add CheckSpelling On to your htaccess file.
The ContentDigest Directive
As the Apache core features documentation says: “This directive enables the generation of Content-MD5 headers as defined in RFC1864 respectively RFC2068. The Content-MD5 header provides an end-to-end message integrity check (MIC) of the entity-body. A proxy or client may check this header for detecting accidental modification of the entity-body in transit.
Note that this can cause performance problems on your server since the message digest is computed on every request (the values are not cached). Content-MD5 is only sent for documents served by the core, and not by any module. For example, SSI documents, output from CGI scripts, and byte range responses do not have this header.”
To turn this on, just add ContentDigest On.
Enable Gzip – Save Bandwidth
# BEGIN GZIP
<ifmodule mod_deflate.c>
# Combine the below two lines - I've split it up for presentation
AddOutputFilterByType DEFLATE text/text text/html text/plain text/xml text/css
application/x-javascript application/javascript
</ifmodule>
# END GZIP
Turn off magic_quotes_gpc
# Only if you use PHP
<ifmodule mod_php4.c>
php_flag magic_quotes_gpc off
</ifmodule>
Set an Expires header and enable Cache-Control
<ifmodule mod_expires.c> ExpiresActive On ExpiresDefault "access plus 1 seconds" ExpiresByType text/html "access plus 7200 seconds" ExpiresByType image/gif "access plus 518400 seconds" ExpiresByType image/jpeg "access plus 518400 seconds" ExpiresByType image/png "access plus 518400 seconds" ExpiresByType text/css "access plus 518400 seconds" ExpiresByType text/javascript "access plus 216000 seconds" ExpiresByType application/x-javascript "access plus 216000 seconds" </ifmodule><ifmodule mod_headers.c> # Cache specified files for 6 days <filesmatch "\.(ico|flv|jpg|jpeg|png|gif|css|swf)$"> Header set Cache-Control "max-age=518400, public" </filesmatch> # Cache HTML files for a couple hours <filesmatch "\.(html|htm)$"> Header set Cache-Control "max-age=7200, private, must-revalidate" </filesmatch> # Cache PDFs for a day <filesmatch "\.(pdf)$"> Header set Cache-Control "max-age=86400, public" </filesmatch> # Cache Javascripts for 2.5 days <filesmatch "\.(js)$"> Header set Cache-Control "max-age=216000, private" </filesmatch> </ifmodule>
RESOURCE LINKS:
http://www.htaccessredirect.net