Welcome to Perishable Press! This article, Stupid .htaccess Tricks, covers just about every .htaccess “trick” in the book, and easily is the site’s most popular resource. I hope that you find it useful, and either way thank you for visiting :)

In addition to this tutorial, you also may want to explore the growing .htaccess archive. Along with all things .htaccess, Perishable Press also focuses on HTML, CSS, PHP, JavaScript, security, and just about every other aspect of web design, blogging, and online success. If these topics are of interest to you, I encourage you to subscribe to Perishable Press for a periodic dose of online enlightenment ;)

Crazy .htaccess skills! Check out my book Check out my book .htaccess made easy . Learn how to optimize your site’s performance, security, usability, and everything in between.

Table of Contents

General Information ^

Note: for a simpler version of this article, check out Useful .htaccess rules for all websites. Not nearly as many techniques, but a good starting point if you’re short on time, or just want something to get your feet wet with .htaccess.

Apache server software provides distributed (i.e., directory-level) configuration via Hypertext Access files. These .htaccess files enable the localized fine-tuning of Apache’s universal system-configuration directives, which are defined in Apache’s main configuration file. The localized .htaccess directives must operate from within a file named .htaccess. The user must have appropriate file permissions to access and/or edit the .htaccess file.

Further, .htaccess file permissions should never allow world write access — a secure permissions setting is “644”, which allows universal read access and user-only write access. Finally, .htaccess rules apply to the parent directory and all subdirectories. Thus to apply configuration rules to an entire website, place the .htaccess file in the site’s root directory.

Commenting .htaccess Code ^

Comments are essential to maintaining control over any involved portion of code. Comments in .htaccess code are fashioned on a per-line basis, with each line of comments beginning with a pound sign # . Thus, comments spanning multiple lines in the .htaccess file require multiple pound signs.

Further, due to the extremely volatile nature of .htaccess voodoo, it is wise to include only alphanumeric characters (and perhaps a few dashes and underscores) in any .htaccess comments. For more information, check out my tutorial commenting your .htaccess code.

Important Notes for .htaccess Noobs ^

As a configuration file, .htaccess is very powerful. Even the slightest syntax error (like a missing space) can result in severe server malfunction. Thus it is crucial to make backup copies of everything related to your site (including any original .htaccess files) before working with your Hypertext Access file(s). It is also important to check your entire website thoroughly after making any changes to your .htaccess file. If any errors or other problems are encountered, employ your backups immediately to restore original functionality.

Also note that, on most machines, .htaccess files are hidden by default. For more information, check out my tutorial, Create .htaccess files on OS X and Windows.

Performance Issues ^

.htaccess directives provide directory-level configuration without requiring access to Apache’s main server cofiguration file ( httpd.conf ). However, due to performance and security concerns, the main configuration file should always be used for server directives whenever possible.

For example, when a server is configured to process .htaccess directives, Apache must search every directory within the domain and load any and all .htaccess files upon every document request. This results in increased page processing time and thus decreases performance. Such a performance hit may be unnoticeable for sites with light traffic, but becomes a more serious issue for more popular websites.

Therefore, .htaccess files should only be used when the main server configuration file is inaccessible. See the Performance Tricks section of this article for more information.

Regex Character Definitions for .htaccess ^

Get this information in PDF format! Visit .htaccess Character Definitions for free download.

# The # instructs the server to ignore the line. used for including comments. each line of comments requires it’s own # . when including comments, it is good practice to use only letters, numbers, dashes, and underscores. this practice will help eliminate/avoid potential server parsing errors. [F] Forbidden: instructs the server to return a 403 “Forbidden” response to the client. [L] Last rule: instructs the server to stop rewriting after the preceding directive is processed. [N] Next: instructs Apache to rerun the rewrite rule until all rewriting directives have been achieved. [G] Gone: instructs the server to deliver a 410 “Gone” response (indicating that the resource no longer exists. [P] Proxy: instructs server to handle requests by mod_proxy . [C] Chain: instructs server to chain the current rule with the previous rule. [R] Redirect: instructs Apache to issue a redirect, causing the client to request the new content. [NC] No Case: defines any associated argument as case-insensitive. That is, “NC” = “No Case”. [PT] Pass Through: instructs mod_rewrite to pass the rewritten URL back to Apache for further processing. [OR] Or: specifies a logical “or” that ties two expressions together such that either one proving true will cause the associated rule to be applied. [NE] No Escape: instructs the server to parse output without escaping characters. [NS] No Subrequest: instructs the server to skip the directive if internal sub-request. [QSA] Append Query String: directs server to add the query string to the end of the expression (URL). [S=x] Skip: instructs the server to skip the next “x” number of rules if a match is detected. [E=variable:value] Environmental Variable: instructs the server to set the environmental variable “variable” to “value”. [T=MIME-type] Mime Type: declares the mime type of the target resource. [] Specifies a character class, in which any character within the brackets will be a match. For example, [xyz] will match either an “x”, “y”, or “z”. []+ Character class in which any combination of items within the brackets will be a match. For example, [xyz]+ will match any number of “x”, “y”, “z”, or any combination of these characters. [^] Specifies not within a character class. For example, [^xyz] will match any character that is neither “x”, “y”, nor “z”. [a-z] A dash ( - ) between two characters within a character class ( [] ) denotes the range of characters between them. For example, [a-zA-Z] matches all lowercase and uppercase letters from “a” thru “z”. a{n} Specifies an exact number, n , of the preceding character. For example, x{3} matches “x” exactly three times. a{n,} Specifies n or more of the preceding character. For example, x{3,} matches “x” three or more times. a{n,m} Specifies a range of numbers, between n and m , of the preceding character. For example, x{3,7} matches “x” three, four, five, six, or seven times. () Used to group characters together, thereby considering them as a single unit. For example, (perishable)?press will match “press”, with or without the “perishable” prefix. ^ Denotes the beginning of a regex (regex = regular expression) test string. That is, begin argument with the proceeding character. $ Denotes the end of a regex (regex = regular expression) test string. That is, end argument with the previous character. ? Declares as optional the preceding character. For example, monzas? will match “monza” or “monzas”, while mon(za)? will match either “mon” or “monza”. That is, x? matches “x” zero or one times. ! Declares negation. For example, !string matches everything except string. . A dot (or period) indicates any single arbitrary character. – Instructs “not to” rewrite the URL, as in (.*) - [F] . + Matches one or more of the preceding character. For example, G+ matches “G” one or more times. * Matches zero or more of the preceding character. For example, you can use .* as a wildcard to match anything (or nothing). | Declares a logical “or” operator. For example, (x|y) matches “x” or “y”. \ Escapes special characters ( ^ $ ! . * | ). For example, use \. to indicate/escape a literal dot. \. Indicates a literal dot (escaped). /* Zero or more slashes. .* Zero or more arbitrary characters. ^$ Defines an empty string. .* The standard pattern for matching everything (or nothing). [^/.] Defines one character that is neither a slash nor a dot. [^/.]+ Defines any number of characters which contains neither slash nor dot. http:// This is a literal statement — in this case, the literal character string, http:// . ^domain.* Defines a string that begins with the term “domain”, which then may be proceeded by any number of any characters. ^domain\.com$ Defines the exact string, “domain.com”. -d Tests if string is an existing directory. -f Tests if string is an existing file. -s Tests if file in test string has a non-zero value.

Redirection Header Codes ^

301 – Moved Permanently

302 – Moved Temporarily

403 – Forbidden

404 – Not Found

410 – Gone

Commenting your .htaccess Files ^

It is an excellent idea to consistenly and logically comment your .htaccess files. Any line in an .htaccess file that begins with the pound sign ( # ) tells the server to ignore it. Multiple lines require multiple pounds and use letters/numbers/dash/underscore only:

# this is a comment # each line must have its own pound sign # use only alphanumeric characters along with dashes - and underscores _

For more information, check out commenting your .htaccess code.

Enable Basic Rewriting ^

Certain servers may not have mod_rewrite (basic rewriting) enabled by default. To ensure mod_rewrite is enabled throughout your site, add the following line once to your site’s root .htaccess file (located before any rewrite rules):

# enable mod_rewrite RewriteEngine on

Enable Symbolic Links ^

Enable symbolic links (symlinks) by adding the following directive to the target directory’s .htaccess file. Note: for the FollowSymLinks directive to function, AllowOverride Options privileges must be enabled from within the server configuration file (see next section for more information):

# enable symbolic links Options +FollowSymLinks

Enable AllowOverride ^

For directives that require AllowOverride in order to function, such as FollowSymLinks (see previous section), the following directive must be added to the server configuration file. For performance considerations, it is important to only enable AllowOverride in the specific directory or directories in which it is required. In the following code chunk, we are enabling the AllowOverride privileges only in the specified directory:

/www/replace/this/with/actual/directory

So to enable AllowOverride for this directory:

# enable allowoverride privileges <Directory /www/replace/this/with/actual/directory> AllowOverride Options </Directory>

Refer to this section for more information about AllowOverride and performance enhancement.

Rename the .htaccess File ^

Not every system enjoys the extension-only format of .htaccess files. Fortunately, you can rename them to whatever you wish, granted the name is valid on your system. Note: This directive must be placed in the server-wide configuration file or it will not work:

# rename .htaccess files AccessFileName ht.access

Note: If you rename your .htaccess files, remember to update any associated configuration settings. For example, if you are protecting your .htaccess file via FilesMatch , remember to inform it of the renamed files:

# protect renamed .htaccess files <FilesMatch "^ht\."> Order deny,allow Deny from all </FilesMatch>

Check out the Security section for more information about protecting files.

Retain Rules Defined in httpd.conf ^

Save yourself time and effort by defining replicate rules for multiple virtual hosts once and only once via your httpd.conf file. Then, simply instruct your target .htaccess file(s) to inherit the httpd.conf rules by including this directive:

# inherit rules from httpd.conf RewriteOptions Inherit

Improving Performance via AllowOverride ^

Limit the extent to which .htaccess files decrease performance by enabling AllowOverride only in required directories. For example, if AllowOverride is enabled throughout the entire site, the server must dig through every directory, searching for .htaccess files that may not even exist. To prevent this, we disable the AllowOverride in the site’s root .htaccess file and then enable AllowOverride only in required directories via the server config file (refer to this section for more information).

Note: if you do not have access to your site’s server config file and also need AllowOverride privileges, do not use this directive.

# increase performance by disabling AllowOverride AllowOverride None

Improving Performance by Passing the Character Set ^

Prevent display errors by specifying the default character set:

# pass the default character set AddDefaultCharset utf-8

Note: replace the utf-8 with the charset that your site is using.

Improving Performance by Preserving Bandwidth ^

To increase performance on PHP enabled servers, add the following directive:

# preserve bandwidth for PHP enabled servers <ifmodule mod_php4.c> php_value zlib.output_compression 16386 </ifmodule>

Disable the Server Signature ^

Here we are disabling the digital signature that would otherwise identify the server:

# disable the server signature ServerSignature Off

Set the Server Timezone ^

Here we are instructing the server to synchronize chronologically according to the time zone of the specified state:

# set the server timezone SetEnv TZ America/Washington

Check out the official list of supported timezones.

Set the Email Address for the Server Administrator ^

Here we are specifying the default email address for the server administrator:

# set the server administrator email SetEnv SERVER_ADMIN default@example.com

Note: only specify your email address if you are okay with getting lots of spam ;)

Improve Site Transfer Speed by Enabling File Caching ^

Dude over at askapache.com explains how to dramatically improve your site’s transfer speed by enabling file caching. Using time in seconds (see conversion chart) to indicate the duration for which cached content should endure, we may generalize the necessary .htaccess rules as follows (edit file types and time value to suit your needs):

# cache images and flash content for one month <FilesMatch ".(flv|gif|jpg|jpeg|png|ico|swf)$"> Header set Cache-Control "max-age=2592000" </FilesMatch>

# cache text, css, and javascript files for one week <FilesMatch ".(js|css|pdf|txt)$"> Header set Cache-Control "max-age=604800" </FilesMatch>

# cache html and htm files for one day <FilesMatch ".(html|htm)$"> Header set Cache-Control "max-age=43200" </FilesMatch>

# implement minimal caching during site development <FilesMatch "\.(flv|gif|jpg|jpeg|png|ico|js|css|pdf|swf|html|htm|txt)$"> Header set Cache-Control "max-age=5" </FilesMatch>

# explicitly disable caching for scripts and other dynamic files <FilesMatch "\.(pl|php|cgi|spl|scgi|fcgi)$"> Header unset Cache-Control </FilesMatch>

# alternate method for file caching ExpiresActive On ExpiresDefault A604800 ExpiresByType image/x-icon A2419200 ExpiresByType application/x-javascript A2419200 ExpiresByType text/css A2419200 ExpiresByType text/html A300

# disable caching for scripts and other dynamic files <FilesMatch "\.(pl|php|cgi|spl|scgi|fcgi)$"> ExpiresActive Off </FilesMatch>

For more information, check out Additional file-types for mod_expires.

Time Conversion Chart

Convert common time intervals into seconds:

300 = 5 minutes 2700 = 45 minutes 3600 = 1 hour 54000 = 15 hours 86400 = 1 day 518400 = 6 days 604800 = 1 week 1814400 = 3 weeks 2419200 = 1 month 26611200 = 11 months 29030400 = 1 year

Set the default language and character set ^

Here is an easy way to set the default language for pages served by your server (edit the language to suit your needs):

# set the default language DefaultLanguage en-US

Likewise, here we are setting the default character set (edit to taste):

# set the default character set AddDefaultCharset UTF-8

Declare specific/additional MIME types ^

# add various mime types AddType application/x-shockwave-flash .swf AddType video/x-flv .flv AddType image/x-icon .ico

Send character set and other headers without meta tags ^

# send the language tag and default character set # AddType 'text/html; charset=UTF-8' html AddDefaultCharset UTF-8 DefaultLanguage en-US

Limit server request methods to GET and PUT ^

# limit server request methods to GET and PUT Options -ExecCGI -Indexes -All RewriteEngine on RewriteCond %{REQUEST_METHOD} ^(TRACE|TRACK|OPTIONS|HEAD) RewriteRule .* - [F]

Learn more about Controlling Request Methods.

Process files based on request method ^

# process files according to server request method Script PUT /cgi-bin/upload.cgi Script GET /cgi-bin/download.cgi

Execute various file types through a cgi script ^

For those special occasions where certain file types need to be processed with some specific cgi script, let em know who sent ya:

# execute all png files via png-script.cgi Action image/png /cgi-bin/png-script.cgi

Prevent Access to .htaccess ^

Add the following code block to your .htaccess file to add an extra layer of security. Any attempts to access the .htaccess file will result in a 403 “Forbidden” response. Learn more.

# secure .htaccess file <Files .htaccess> Order allow,deny Deny from all </Files>

Of course, your first layer of defense to protect .htaccess (and other sensitive) files involves setting the file permissions via CHMOD to be as restrictive as possible. If ever in doubt, ask your web host for help.

Prevent Access to a Specific File ^

To restrict access to a specific file, add the following code block and edit the file name, secretfile.jpg , with the name of the file that you wish to protect:

# prevent viewing of a specific file <files secretfile.jpg> Order allow,deny Deny from all </files>

For further infos, check out Protect files with .htaccess.

Prevent access to multiple file types ^

To restrict access to a variety of file types, add the following code block and edit the file types within parentheses to match the extensions of any files that you wish to protect:

<FilesMatch "\.(htaccess|htpasswd|ini|phps|fla|psd|log|sh)$"> Order Allow,Deny Deny from all </FilesMatch>

For further infos, check out Protect files with .htaccess.

Prevent Unauthorized Directory Browsing ^

Prevent unauthorized directory browsing by instructing the server to serve a 403 “Forbidden” response for any request to view a directory. For example, if your site is missing its default index page, everything within the root of your site will be accessible to all visitors. To prevent this, include the following .htaccess rule:

# disable directory browsing Options All -Indexes

Conversely, to enable directory browsing, use the following directive:

# enable directory browsing Options All +Indexes

Likewise, this rule will prevent the server from listing directory contents:

# prevent folder listing IndexIgnore *

And, finally, the IndexIgnore directive may be used to prevent the display of select file types:

# prevent display of select file types IndexIgnore *.wmv *.mp4 *.avi *.etc

For more information, check out What is Options All? and Better Default Directory Views with HTAccess.

Change Default Index Page ^

This rule tells the server to search for and serve business.html as the default directory index. This rule must exist in the .htaccess files of the root directory for which you wish to replace the default index file (e.g., index.html ):

# serve alternate default index page DirectoryIndex business.html

This rule is similar, only in this case, the server will scan the root directory for the listed files and serve the first match it encounters. The list is read from left to right:

# serve first available alternate default index page from series DirectoryIndex filename.html index.cgi index.pl default.htm

For more information, check out Better Default Directory Views with HTAccess.

Disguise Script Extensions ^

To enhance security, disguise scripting languages by replacing actual script extensions with dummy extensions of your choosing. For example, to change the .foo extension to .php , add the following line to your .htaccess file and rename all affected files accordingly:

# serve foo files as php files AddType application/x-httpd-php .foo

# serve foo files as cgi files AddType application/x-httpd-cgi .foo

Limit Access to the Local Area Network (LAN) ^

# limit access to local area network <Limit GET POST PUT> Order deny,allow Deny from all Allow from 192.168.0.0/33 </Limit>

Secure Directories by IP Address and/or Domain ^

In the following example, all IP addresses are allowed access except for 12.345.67.890 and example.com :

# allow all except those indicated here <Limit GET POST PUT> Order allow,deny Allow from all Deny from 12.345.67.890 Deny from example\.com </Limit>

In the following example, all IP addresses are denied access except for 12.345.67.890 and example.com :

# deny all except those indicated here <Limit GET POST PUT> Order deny,allow Deny from all Allow from 12.345.67.890 Allow from example\.com </Limit>

This is how to block unwanted visitors based on the referring domain. You can also save bandwidth by blocking specific file types — such as .jpg , .zip , .mp3 , .mpg — from specific referring domains. Simply replace scumbag and wormhole with the offending domains of your choice:

# block visitors referred from indicated domains <IfModule mod_rewrite.c> RewriteEngine on RewriteCond %{HTTP_REFERER} scumbag\.com [NC,OR] RewriteCond %{HTTP_REFERER} wormhole\.com [NC,OR] RewriteRule .* - [F] </ifModule>

For more information, check out How to Block Bad Bots and Eight Ways to Redirect with Apache’s mod_rewrite.

Allow or deny domain access for specified range of IP addresses ^

There are several effective ways to block a range of IP addresses via .htaccess. This first method blocks an IP range specified by their CIDR (Classless Inter-Domain Routing) number. This method is useful for blocking mega-spammers such as RIPE, Optinet, and others.

If, for example, you find yourself adding line after line of Apache Deny directives for addresses beginning with the same first few numbers, choose one of them and try a whois lookup. Listed within the whois results will be the CIDR value representing every IP address associated with that particular network.

Thus, blocking via CIDR is an effective way to eloquently prevent all IP instances of the offender from accessing your site. Here is a generalized example for blocking by CIDR (edit values to suit your needs):

# block IP range by CIDR number <Limit GET POST PUT> Order allow,deny Allow from all Deny from 10.1.0.0/16 Deny from 80.0.0/8 </Limit>

Likewise, to allow an IP range by CIDR number:

# allow IP range by CIDR number <Limit GET POST PUT> Order deny,allow Deny from all Allow from 10.1.0.0/16 Allow from 80.0.0/8 </Limit>

Another effective way to block an entire range of IP addresses involves truncating digits until the desired range is represented. As an IP address is read from left to right, its value represents an increasingly specific address.

For example, a fictitious IP address of 99.88.77.66 would designate some uniquely specific IP address. Now, if we remove the last two digits ( 66 ) from the address, it would represent any address beginning with the remaining digits. That is, 99.88.77 represents 99.88.77.1 , 99.88.77.2 , … 99.88.77.99 , …etc. Likewise, if we then remove another pair of digits from the address, its range suddenly widens to represent every IP address 99.88.x.y , where x and y represent any valid set of IP address values (i.e., you would block 256 * 256 = 65,536 unique IP addresses).

Following this logic, it is possible to block an entire range of IP addresses to varying degrees of specificity. Here are few generalized lines exemplifying proper .htaccess syntax (edit values to suit your needs):

# block IP range by address truncation <Limit GET POST PUT> Order allow,deny Allow from all Deny from 99.88.77.66 Deny from 99.88.77.* Deny from 99.88.*.* Deny from 99.*.*.* </Limit>

Likewise, to allow an IP range by address truncation:

# allow IP range by address truncation <Limit GET POST PUT> Order deny,allow Deny from all Allow from 99.88.77.66 Allow from 99.88.77.* Allow from 99.88.*.* Allow from 99.*.*.* </Limit>

Note: for these examples, we are using <Limit> to restrict the rule set to the specified request methods ( GET , POST , and PUT ). So you can either customize which methods should be targeted, or to target all requests, simply remove the surrounding <Limit> container.

Block or allow multiple IP addresses on one line ^

Save a little space by blocking multiple IP addresses or ranges on one line. Here are few examples (edit values to suit your needs):

# block two unique IP addresses Deny from 99.88.77.66 11.22.33.44

# block three ranges of IP addresses Deny from 99.88 99.88.77 11.22.33

Likewise, to allow multiple IP addresses or ranges on one line:

# allow two unique IP addresses Allow from 99.88.77.66 11.22.33.44

# allow three ranges of IP addresses Allow from 99.88 99.88.77 11.22.33

Miscellaneous rules for blocking and allowing IP addresses ^

Here are few miscellaneous rules for blocking various types of IP addresses. These rules may be adapted to allow the specified IP values by simply changing the Deny directive to Allow . Check ’em out (edit values to suit your needs):

# block a partial domain via network/netmask values Deny from 99.1.0.0/255.255.0.0

# block a single domain Deny from 99.88.77.66

# block domain.com but allow sub.domain.com Order deny,allow Deny from domain.com Allow from sub.domain.com

Stop Hotlinking, Serve Alternate Content ^

To serve ’em some unexpected alternate content when hotlinking is detected, employ the following code, which will protect all files of the types included in the last line (add more types as needed). Remember to replace the dummy path names with real ones. Also, the name of the nasty image being served in this case is eatme.jpe , as indicated in the line containing the RewriteRule .

# stop hotlinking and serve alternate content <IfModule mod_rewrite.c> RewriteEngine on RewriteCond %{HTTP_REFERER} !^$ RewriteCond %{HTTP_REFERER} !^http://(www\.)?domain\.com/.*$ [NC] RewriteRule .*\.(gif|jpg)$ http://www.domain.com/eatme.jpe [R,NC,L] </ifModule>

Note: To deliver a standard (or custom, if configured) error page instead of some nasty image of the Fonz, replace the line containing the RewriteRule in the above .htaccess directive with the following line:

# serve a standard 403 forbidden error page RewriteRule .*\.(gif|jpg)$ - [F,L]

Note: To grant linking permission to a site other than yours, insert this code block after the line containing the domain.com string. Remember to replace goodsite.com with the actual site domain:

# allow linking from the following site RewriteCond %{HTTP_REFERER} !^http://(www\.)?goodsite\.com/.*$ [NC]

For examples of allowing other sites access to your protected files, check out Allow Feedburner Access to Hotlink-Protected Images and Allow Google Reader Access to Hotlink-Protected Images. Also, for an in-depth tutorial on hotlink protection, check out Creating the Ultimate htaccess Anti-Hotlinking Strategy.

Block Evil Robots, Site Rippers, and Offline Browsers ^

Eliminate some of the unwanted scum from your userspace by injecting this handy block of code. After such, any listed agents will be denied access and receive an error message instead. Please be advised that there are much more comprehensive blacklists available this example has been truncated for performance purposes. Note: DO NOT include the [OR] on the very last RewriteCond or your server will throw an error.

# deny access to evil robots site rippers offline browsers and other nasty scum RewriteBase / RewriteCond %{HTTP_USER_AGENT} ^Anarchie [OR] RewriteCond %{HTTP_USER_AGENT} ^ASPSeek [OR] RewriteCond %{HTTP_USER_AGENT} ^attach [OR] RewriteCond %{HTTP_USER_AGENT} ^autoemailspider [OR] RewriteCond %{HTTP_USER_AGENT} ^Xaldon\ WebSpider [OR] RewriteCond %{HTTP_USER_AGENT} ^Xenu [OR] RewriteCond %{HTTP_USER_AGENT} ^Zeus.*Webster [OR] RewriteCond %{HTTP_USER_AGENT} ^Zeus RewriteRule ^.* - [F,L]

Or, instead of delivering a friendly error message (i.e., the last line), send these bad boys to the hellish website of your choice by replacing the RewriteRule in the last line with one of the following two examples:

# send em to a hellish website of your choice RewriteRule ^.*$ http://www.hellish-website.com [R,L]

Or, to send em to a virtual blackhole of fake email addresses:

# send em to a virtual blackhole of fake email addresses RewriteRule ^.*$ http://english-61925045732.spampoison.com [R,L]

You may also add specific referrers to your blacklist by using HTTP_REFERER . Here, we use the infamously scummy domain, iaea.org as our blocked example, and we use yourdomain as your domain (the domain to which you are blocking iaea.org ):

RewriteCond %{HTTP_REFERER} ^http://www.iaea.org$ RewriteRule !^http://[^/.]\.yourdomain\.com.* - [F,L]

For more information about blocking malicious requests, check out How to Block Bad Bots and the Perishable Press 6G Firewall.

More Stupid Blocking Tricks ^

Note: Although these redirect techniques are aimed at blocking and redirecting nasty scum-sucking sites, the directives may also be employed for friendly redirection purposes:

# redirect any request for anything from spamsite to differentspamsite RewriteCond %{HTTP_REFERER} ^http://.*spamsite.*$ [NC] RewriteRule .* http://www.differentspamsite.com [R]

# redirect all requests from spamsite to an image of something at differentspamsite RewriteCond %{HTTP_REFERER} ^http://.*spamsite.*$ [NC] RewriteRule .* http://www.differentspamsite/something.jpg [R]

# redirect traffic from a certain address or range of addresses to another site RewriteCond %{REMOTE_ADDR} 192.168.10.* RewriteRule .* http://www.differentspamsite.com/index.html [R]

For more information, check out Eight Ways to Redirect with Apache’s mod_rewrite.

Even More Scum-Blocking Tricks ^

Here is a step-by-step series of code blocks that should equip you with enough knowledge to block any/all necessary entities. Read through the set of code blocks, observe the patterns, and then copy, combine and customize to suit your specific scum-blocking needs:

# set variables for user agents and referers and ip addresses SetEnvIfNoCase User-Agent ".*(user-agent-you-want-to-block|php/perl).*" BlockedAgent SetEnvIfNoCase Referer ".*(block-this-referrer|and-this-referrer|and-this-referrer).*" BlockedReferer SetEnvIfNoCase REMOTE_ADDR ".*(666.666.66.0|22.22.22.222|999.999.99.999).*" BlockedAddress

# set variable for any class B network coming from a given netblock SetEnvIfNoCase REMOTE_ADDR "66.154.*" BlockedAddress

# set variable for two class B networks 198.25.0.0 and 198.26.0.0 SetEnvIfNoCase REMOTE_ADDR "198.2(5|6)\..*" BlockedAddress

# deny any matches from above and send a 403 denied <Limit GET POST PUT> Order deny,allow Deny from env=BlockedAgent Deny from env=BlockedReferer Deny from env=BlockedAddress Allow from all </Limit>

For more information, check out How to Block Bad Bots.

For in-depth coverage of password-protecting directories, check out my tutorial, HTAccess Password-Protection Tricks. Also, here is an excellent online tool for generating the necessary elements for a password-protected directory: .htaccess Password Generator.

Secure site contents by requiring user authentication for specified files and/or directories. The first example shows how to password-protect the specified file, secure.php .

# password-protect single file <Files secure.php> AuthType Basic AuthName "Prompt" AuthUserFile /home/path/.htpasswd Require valid-user </Files>

The second example employs the FilesMatch directive to protect any/all files which match any of the specified character strings, execute , index , secure , insanity , biscuit ,.

# password-protect multiple files <FilesMatch "^(execute|index|secure|insanity|biscuit)*$"> AuthType basic AuthName "Development" AuthUserFile /home/path/.htpasswd Require valid-user </FilesMatch>

The third example demonstrates how to protect an entire directory. So if this rule set is included in a directory named /private/ , all files and subdirectories within /private/ will be protected.

# password-protect the directory in which this .htaccess rule resides AuthType basic AuthName "This directory is protected" AuthUserFile /home/path/.htpasswd AuthGroupFile /dev/null Require valid-user

The fourth example provides password-protection for all IPs except that which is specified, 99.88.77.66 .

# password-protect directory for every IP except the one specified # place in .htaccess file of a directory to protect that entire directory AuthType Basic AuthName "Personal" AuthUserFile /home/path/.htpasswd Require valid-user Allow from 99.88.77.66 Satisfy Any

Remember to edit these rules according to your specific needs. For more information on protecting resources with .htaccess, check out HTAccess Password-Protection Tricks.

Require SSL (Secure Sockets Layer) ^

Here is an excellent method for requiring SSL:

# require SSL SSLOptions +StrictRequire SSLRequireSSL SSLRequire %{HTTP_HOST} eq "domain.tld" ErrorDocument 403 https://domain.tld # require SSL without mod_ssl RewriteCond %{HTTPS} !=on [NC] RewriteRule ^.*$ https://%{SERVER_NAME}%{REQUEST_URI} [R,L]

For more techniques involving SSL/HTTPS, check out Redirect HTTP to HTTPS.

Automatically CHMOD Various File Types ^

This method is great for ensuring the CHMOD settings for various file types. Employ the following rules in the root .htaccess file to affect all specified file types, or place in a specific directory to affect only those files (edit file types according to your needs):

# ensure CHMOD settings for specified file types # remember to never set CHMOD 777 unless you know what you are doing # files requiring write access should use CHMOD 766 rather than 777 # keep specific file types private by setting their CHMOD to 400 chmod .htpasswd files 640 chmod .htaccess files 644 chmod php files 600

Disguise all file extensions ^

This method will disguise all file types (i.e., any file extension) and present them as .php files (or whichever extension you choose):

# diguise all file extensions as php ForceType application/x-httpd-php

Protect against denial-of-service (DOS) attacks by limiting file upload size ^

One method to help protect your server against DOS attacks involves limiting the maximum allowable size for file uploads. Here, we are limiting file upload size to 10240000 bytes, which is equivalent to around 10 megabytes. For this rule, file sizes are expressed in bytes. Check here for help with various file size conversions.

# protect against DOS attacks by limiting file upload size LimitRequestBody 10240000

For more infos, check out Limit File Upload Size and Limit HTTP Request Size.

Secure directories by disabling execution of scripts ^

Prevent malicious brainiacs from actively scripting secure directories by adding the following rules to the representative .htaccess file (edit file types to suit your needs):

# secure directory by disabling script execution AddHandler cgi-script .php .pl .py .jsp .asp .htm .shtml .sh .cgi Options -ExecCGI

Usability Tricks ^

Minimize CSS Image Flicker in IE6 ^

Add the following .htaccess rules to minimize or even eliminate CSS background-image “flickering” in MSIE6:

# minimize image flicker in IE6 ExpiresActive On ExpiresByType image/gif A2592000 ExpiresByType image/jpg A2592000 ExpiresByType image/png A2592000

Deploy Custom Error Pages ^

Replicate the following patterns to serve your own set of custom error pages. Simply replace the /errors/###.html with the correct path and file name. Also change the ### preceding the path to summon pages for other errors. Note: your custom error pages must be larger than 512 bytes or they will be completely ignored by Internet Explorer:

# serve custom error pages ErrorDocument 400 /errors/400.html ErrorDocument 401 /errors/401.html ErrorDocument 403 /errors/403.html ErrorDocument 404 /errors/404.html ErrorDocument 500 /errors/500.html

For more details, check out Custom HTTP Errors via htaccess.

Provide a Universal Error Document ^

# provide a universal error document RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^.*$ /dir/error.php [L]

For more information, check out Custom HTTP Errors via htaccess.

Employ Basic URL Spelling Check ^

This bit of voodoo will auto-correct simple spelling errors in the URL:

# automatically corect simple speling erors <IfModule mod_speling.c> CheckSpelling On </IfModule>

Instruct browser to download multimedia files rather than display them ^

Here is a useful method for delivering multimedia file downloads to your users. Typically, browsers will attempt to play or stream such files when direct links are clicked. With this method, provide a link to a multimedia file and a dialogue box will provide users the choice of saving the file or opening it. Here are a few .htaccess rules demonstrating the technique (edit file types according to your specific needs):

# instruct browser to download multimedia files AddType application/octet-stream .avi AddType application/octet-stream .mpg AddType application/octet-stream .wmv AddType application/octet-stream .mp3

For more information, check out Force file download with .htaccess.

Display source code for dynamic files ^

There are many situations where site owners may wish to display the contents of a dynamic file rather than executing it as a script. To exercise this useful technique, create a directory in which to place dynamic files that should be displayed rather than executed, and add the following line of code to the .htaccess file belonging to that directory. This method is known to work for .pl , .py , and .cgi file types. Here it is:

RemoveHandler cgi-script .pl .py .cgi

Redirect visitors to a temporary site during site development ^

During web development, maintenance, or repair, send your visitors to an alternate site while retaining full access for yourself. This is a very useful technique for preventing visitor confusion or dismay during those awkward, web-development moments. Here are the generalized .htaccess rules to do it (edit values to suit your needs):

# redirect all visitors to alternate site but retain full access for you ErrorDocument 403 http://www.alternate-site.com Order deny,allow Deny from all Allow from 99.88.77.66

For more in-depth information and advanced techniques, check out the following tutorials:

Provide a password prompt for visitors during site development ^

Here is another possible solution for “hiding” your site during those private, site-under-construction moments. Here we are instructing Apache to provide visitors with a password prompt while providing open access to any specifically indicated IP addresses or URLs. Edit the following code according to your IP address and other development requirements (thanks to askapache.com for sharing this trick):

# password prompt for visitors AuthType basic AuthName "This site is currently under construction" AuthUserFile /home/path/.htpasswd AuthGroupFile /dev/null Require valid-user

# allow webmaster and any others open access Order Deny,Allow Deny from all Allow from 111.222.33.4 Allow from favorite.validation/services/ Allow from googlebot.com Satisfy Any

For more in-depth information and advanced techniques, check out the following tutorials:

Prevent file or directory access according to specified time periods ^

Prevent viewing of all pictures of Fonzi during the midnight hour — or any files during any time period — by using this handy .htaccess rule set:

# prevent access during the midnight hour RewriteCond %{TIME_HOUR} ^12$ RewriteRule ^.*$ - [F,L]

# prevent access throughout the afternoon RewriteCond %{TIME_HOUR} ^(12|13|14|15)$ RewriteRule ^.*$ - [F,L]

For more information on numerical regular expressions, check out Redirecting URLs that Include Numbers. The article is about redirecting requests, but contains a lot of useful regex infos for matching numbers.

Redirect Tricks ^

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:

# enable rewrite engine RewriteEngine on

Note: It’s fine to include this directive multiple times in the same .htaccess file.

Redirect from “www” domain to “non-www” domain ^

This technique is referred to as www canonicalization. It uses a “301 redirect” to establish a permanent redirect from the “www” version of a domain to its 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 proper 301 response. Further, always include a trailing slash / when linking directories. Finally, be consistent with the www subdomain 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]

This code redirects all requests for any URL at www.domain.tld to their respective URLs at domain.tld (i.e., it removes the www prefix from all requests). For more information on www-canonicalization, check out Canonical www via .htaccess and Canonical URLs for a single page site.

Redirect from an old domain to a new domain ^

For a basic domain change from old-domain.com to new-domain.com (with identical files and resources on both domains), use the Rewrite rule to remap the old domain to the new domain. 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]

Once in place, this rule set redirects all requests from old-domain.com to new-domain.com .

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 perishablepress.com , we would replace some-string with perish in the following code block:

# redirect all variations of a specific string RewriteRule ^some-string http://www.domain.com/index.php/blog/target [R]

Here are two other methods for accomplishing string-related mapping tasks:

# map variations to same directory on same server AliasMatch ^/director(y|ies) /www/docs/target

# map variations to same directory on different server RedirectMatch ^/[dD]irector(y|ies) http://domain.com

Refer to the section on Regex Character Definitions for explanations of the regular expressions used in these examples.

Other Fantastic Redirect Tricks ^

Redirect an entire site via 301 “Permanent” server response:

# redirect an entire site via 301 Redirect 301 / http://www.domain.com/

Redirect a specific file via 301 “Permanent” server response::

# 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 (i.e., permanent may be used instead of 301 , just alternate syntax):

# 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 (instead of Redirect ):

# redirect all requests via RedirectMatch RedirectMatch 301 (.*) http://www.domain.com/index.html

The main difference between RedirectMatch and Redirect is that RedirectMatch allows pattern matching via regular expressions.

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 ^

Here are some further examples of redirecting and rewriting with Apache’s rewrite module, mod_rewrite .

# rewrite only if file is not found RewriteCond %{REQUEST_FILENAME} !-f RewriteRule ^(.+)special\.html?$ cgi-bin/special/special-html/$1

# rewrite only if image is not found RewriteCond %{REQUEST_FILENAME} !-f RewriteRule images/special/(.*).gif cgi-bin/special/mkgif?$1

# 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 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 RewriteCond %{REQUEST_URI} /search/(.*) [NC] RewriteRule (.*) http://www.google.com/search?q=$1 [R,NC,L]

# deny request based on 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]

Learn more and check out some practical redirect examples in my tutorial, redirecting stuff with .htaccess.

More fun with Redirect and RedirectMatch ^

For redirects that are on the same domain, like when you move a file into a new directory, you can omit the protocol and domain from the destination URI. Here is a basic example:

# redirect for a single file Redirect 301 /old-dir/old-file.html /new-dir/new-file.html

Here we are redirecting /old-dir/old-file.html to /new-dir/new-file.html on the same domain. So we excluded http://domain.com from the destination URI (compare with other examples in this section).

To redirect multiple files, we can pattern-match using any regex that is necessary. For example, we can use (.*) to match anything (or nothing):

# redirect multiple files RedirectMatch 301 /dir/xyz/(.*) http://domain.com/$1

Here we are using RedirectMatch to match any request for /xyz/ or any file or directory contained in /xyz/ . If the request matches, it will be redirected via 301 “Permanent” status code to the new domain. The $1 in this example represents whatever is matched by (.*) . So if the requested URI is /dir/xyz/bananaz.php , it will be redirected to http://domain.com/bananaz.php .

To redirect an entire, such that every URL is redirected to the same URL on the new domain, use Redirect :

# redirect all URLs to new domain Redirect 301 / http://new-domain.com/

Alternately, if you want to redirect all requests from the old domain to the same URL on the new domain (e.g., the homepage), we can use RedirectMatch , like:

# redirect all URLs to same URL RedirectMatch 301 / http://new-domain.com/

Notice the difference: RedirectMatch redirects everything to the same location, whereas Redirect redirects each URL to the same URL on the new domain.

For more information on redirecting URLs, check out the following tutorials:

WordPress Tricks ^

Secure WordPress Contact Forms ^

Protect your insecure WordPress contact forms against online unrighteousness by verifying the domain from whence the form is called. Remember to replace the domain.com and contact.php with your domain and contact-form file names, respectively.

# secure wordpress contact forms via referrer check RewriteCond %{HTTP_REFERER} !^http://www.domain.com/.*$ [NC] RewriteCond %{REQUEST_POST} .*contact.php$ RewriteRule .* - [F]

For some related discussion, also check out my tutorials, Protect Against Malicious POST Requests and Secure Visitor Posting for WordPress.

WordPress Permalinks ^

In my article, The .htaccess rules for all WordPress Permalinks, I reveal the precise .htaccess directives used by the WordPress blogging platform for permalink functionality. Here, for the sake of completeness, we repeat the directives only. For more details please refer to the original article. There are two possibilities for this technique: WordPress installed in the site root directory, or WordPress installed in its own directory (subdirectory).

WordPress installed in site root

If WordPress is installed in the site’s root directory, WordPress creates and uses the following .htaccess directives:

# BEGIN WordPress <IfModule mod_rewrite.c> RewriteEngine On RewriteBase / RewriteRule ^index\.php$ - [L] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule . /index.php [L] </IfModule> # END WordPress

No changes are required, strictly plug-&-play.

WordPress installed in its own directory

If WordPress is installed in some subdirectory /foo/ , WordPress creates and uses the following .htaccess directives:

# BEGIN WordPress <IfModule mod_rewrite.c> RewriteEngine On RewriteBase /wordpress/ RewriteRule ^index\.php$ - [L] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule . /wordpress/index.php [L] </IfModule> # END WordPress

Again, no changes are required, strictly plug-&-play. For more information about either of these permalink techniques, refer to the original article, The .htaccess rules for all WordPress Permalinks.

More .htaccess techniques for WordPress

For more WordPress techniques, check out these resources:

Also check out my book, .htaccess made easy — it includes an entire chapter of awesome .htaccess WordPress techniques.

Random .htaccess Tricks ^

Activate SSI for HTML/SHTML file types ^

# activate SSI for HTML and or SHTML file types AddType text/html .html AddType text/html .shtml AddHandler server-parsed .html AddHandler server-parsed .shtml AddHandler server-parsed .htm

Grant CGI access in a specific directory ^

# grant CGI access in a specific directory Options +ExecCGI AddHandler cgi-script cgi pl # to enable all scripts in a directory use the following SetHandler cgi-script

Disable magic_quotes_gpc for PHP enabled servers ^

# turn off magic_quotes_gpc for PHP enabled servers <ifmodule mod_php4.c> php_flag magic_quotes_gpc off </ifmodule>

Enable MD5 digests ^

Note: enabling this directive may result in a relative decrease in server performance.

# enable MD5 digests via ContentDigest ContentDigest On

Expression Engine Tricks ^

# redirect Atom and RSS requests RewriteRule .*atom.xml$ http://www.yoursite.com/index.php/weblog/rss_atom/ [R] RewriteRule .*rss.xml$ http://www.yoursite.com/index.php/weblog/rss_2.0/ [R]

# redirect all index.html files RewriteRule /.*index.html$ http://www.domain.com/index.php [R]