htaccess Tricks #6 – Redirect Tricks
October 17th, 2008 | by whazup |
Important Note About Redirecting via mod_rewrite
For all redirects using the mod_rewrite directive, it is necessary to have the RewriteEngine enabled. It is common practice to enable the mod_rewrite directive in either the server configuration file or at the top of the site’s root htaccess file. If the mod_rewrite directive is not included in either of these two places, it should be included as the first line in any code block that utilizes a rewrite function (i.e., mod_rewrite), but only needs to be included once for each htaccess file. The proper mod_rewrite directive is included here for your convenience, but may or may not also be included within some of the code blocks provided in this article:
# initialize and enable rewrite engine
RewriteEngine on
Redirect from http://www.domain.com to http://domain.com
This method uses a “301 redirect” to establish a permanent redirect from the “www-version” of a domain to its respectively corresponding “non-www version”. Be sure to test immediately after preparing 301 redirects and remove it immediately if any errors occur. Use a “server header checker” to confirm a positive 301 response. Further, always include a trailing slash “/” when linking directories. Finally, be consistent with the “www” in all links (either use it always or never).
# permanently redirect from www domain to non-www domain
RewriteEngine on
Options +FollowSymLinks
RewriteCond %{HTTP_HOST} ^www\.domain\.tld$ [NC]
RewriteRule ^(.*)$ http://domain.tld/$1 [R=301,L]
Redirect from http://old-domain.com to http://new-domain.com
For a basic domain change from “old-domain.com” to “new-domain.com” (and folder/file names have not been changed), use the Rewrite rule to remap the old domain to the new domain. When checking the redirect live, the old domain may appear in the browser’s address bar. Simply check an image path (right-click an image and select “properties”) to verify proper redirection. Remember to check your site thoroughly after implementing this redirect.
# redirect from old domain to new domain
RewriteEngine On
RewriteRule ^(.*)$ http://www.new-domain.com/$1 [R=301,L]
Redirect String Variations to a Specific Address
For example, if we wanted to redirect any requests containing the character string, “perish”, to our main page at http://perishablepress.com/, we would replace “some-string” with “perish” in the following code block:
# redirect any variations of a specific character string to a specific address
RewriteRule ^some-string http://www.domain.com/index.php/blog/target [R]
Here are two other methods for accomplishing string-related mapping tasks:
# map URL variations to the same directory on the same server
AliasMatch ^/director(y|ies) /www/docs/target
# map URL variations to the same directory on a different server
RedirectMatch ^/[dD]irector(y|ies) http://domain.com
Other Fantastic Redirect Tricks
Redirect an entire site via 301:
# redirect an entire site via 301
redirect 301 / http://www.domain.com/
Redirect a specific file via 301:
# redirect a specific file via 301
redirect 301 /current/currentfile.html http://www.newdomain.com/new/newfile.html
Redirect an entire site via permanent redirect:
# redirect an entire site via permanent redirect
Redirect permanent / http://www.domain.com/
Redirect a page or directory via permanent redirect:
# redirect a page or directory
Redirect permanent old_file.html http://www.new-domain.com/new_file.html
Redirect permanent /old_directory/ http://www.new-domain.com/new_directory/
Redirect a file using RedirectMatch:
# redirect a file using RedirectMatch
RedirectMatch 301 ^.*$ http://www.domain.com/index.html
Note: When redirecting specific files, use Apache‘s Redirect rule for files within the same domain. Use Apache‘s RewriteRule for any domains, especially if they are different. The RewriteRule is more powerful than the Redirect rule, and thus should serve you more effectively.
Thus, use the following for a stronger, harder page redirection (first line redirects a file, second line a directory, and third a domain):
# redirect files directories and domains via RewriteRule
RewriteRule http://old-domain.com/old-file.html http://new-domain.com/new-file.html
RewriteRule http://old-domain.com/old-dir/ http://new-domain.com/new-dir/
RewriteRule http://old-domain.com/ http://new-domain.com/
Send visitors to a subdomain
This rule will ensure that all visitors are viewing pages via the subdomain of your choice. Edit the “subdomain”, “domain”, and “tld” to match your subdomain, domain, and top-level domain respectively:
# send visitors to a subdomain
RewriteCond %{HTTP_HOST} !^$
RewriteCond %{HTTP_HOST} !^subdomain\.domain\.com$ [NC]
RewriteRule ^/(.*)$ http://subdomain.domain.tld/$1 [L,R=301]
More fun with RewriteCond and RewriteRule
# rewrite only if the file is not found
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.+)special\.html?$ cgi-bin/special/special-html/$1
# rewrite only if an image is not found
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule images/special/(.*).gif cgi-bin/special/mkgif?$1
# seo-friendly rewrite rules for various directories
RewriteRule ^(.*)/aud/(.*)$ $1/audio-files/$2 [L,R=301]
RewriteRule ^(.*)/img/(.*)$ $1/image-files/$2 [L,R=301]
RewriteRule ^(.*)/fla/(.*)$ $1/flash-files/$2 [L,R=301]
RewriteRule ^(.*)/vid/(.*)$ $1/video-files/$2 [L,R=301]
# broswer sniffing via htaccess environmental variables
RewriteCond %{HTTP_USER_AGENT} ^Mozilla.*
RewriteRule ^/$ /index-for-mozilla.html [L]
RewriteCond %{HTTP_USER_AGENT} ^Lynx.*
RewriteRule ^/$ /index-for-lynx.html [L]
RewriteRule ^/$ /index-for-all-others.html [L]
# redirect query to Google search
Options +FollowSymlinks
RewriteEngine On
RewriteCond %{REQUEST_URI} .google\.php*
RewriteRule ^(.*)$ ^http://www.google.com/search?q=$1 [R,NC,L]
# deny request according to the request method
RewriteCond %{REQUEST_METHOD} ^(TRACE|TRACK|OPTIONS|HEAD)$ [NC]
RewriteRule ^.*$ – [F]
# redirect uploads to a better place
RewriteCond %{REQUEST_METHOD} ^(PUT|POST)$ [NC]
RewriteRule ^(.*)$ /cgi-bin/upload-processor.cgi?p=$1 [L,QSA]
More fun with Redirect 301 and RedirectMatch 301
# seo friendly redirect for a single file
Redirect 301 /old-dir/old-file.html http://domain.com/new-dir/new-file.html
# seo friendly redirect for multiple files
# redirects all files in dir directory with first letters xyz
RedirectMatch 301 /dir/xyz(.*) http://domain.com/$1
# seo friendly redirect entire site to a different domain
Redirect 301 / http://different-domain.com
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Tags: htaccess, Redirect, Tricks
