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diff --git a/APACHE_1_3_42/htdocs/manual/howto/htaccess.html b/APACHE_1_3_42/htdocs/manual/howto/htaccess.html new file mode 100644 index 0000000000..794e5bb09b --- /dev/null +++ b/APACHE_1_3_42/htdocs/manual/howto/htaccess.html @@ -0,0 +1,416 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" + "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> + +<html xmlns="http://www.w3.org/1999/xhtml"> + <head> + <meta name="generator" content="HTML Tidy, see www.w3.org" /> + + <title>Apache Tutorial: .htaccess files</title> + </head> + + <body bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#000080" + alink="#FF0000"> + <!--#include virtual="header.html" --> + + <h1 align="CENTER"><code>.htaccess</code> files</h1> + <!-- INDEX BEGIN --> + + <ul> + <li><a href="#what">What they are/How to use them</a></li> + + <li><a href="#when">When (not) to use <code + class="file">.htaccess</code></a> files</li> + + <li><a href="#how">How directives are applied</a></li> + + <li><a href="#auth">Authentication example</a></li> + + <li><a href="#ssi">Server side includes example</a></li> + + <li><a href="#cgi">CGI example</a></li> + + <li><a href="#troubleshoot">Troubleshooting</a></li> + </ul> + <!-- Index End --> + + <table border="1"> + <tr> + <td valign="top"><strong>Related Modules</strong><br /> + <br /> + <code><a href="../mod/core.html">core</a></code><br /> + <code><a href="../mod/mod_auth.html">mod_auth</a></code><br /> + <code><a href="../mod/mod_cgi.html">mod_cgi</a></code><br /> + <code><a href="../mod/mod_include.html">mod_include</a><br /> + </code> <a href="../mod/mod_mime.html">mod_mine</a><br /> + </td> + + <td valign="top"><strong>Related Directives</strong><br /> + <br /> + <code><a + href="../mod/core.html#accessfilename">AccessFileName</a></code><br /> + <code><a + href="../mod/core.html#allowoverride">AllowOverride</a></code><br /> + <code><a href="../mod/core.html#options">Options</a></code><br /> + <code><a + href="../mod/mod_mime.html#addhandler">AddHandler</a></code><br /> + <code><a + href="../mod/mod_mime.html#sethandler">SetHandler</a></code><br /> + <code><a + href="../mod/core.html#authtype">AuthType</a></code><br /> + <code><a + href="../mod/core.html#authname">AuthName</a></code><br /> + <code><a + href="../mod/mod_auth.html#authuserfile">AuthUserFile</a></code><br /> + <code><a + href="../mod/mod_auth.html#authuserfile">AuthGroupFile</a></code><br /> + <code><a href="../mod/core.html#require">Require</a></code><br /> + </td> + </tr> + </table> + <hr /> + + <h2><a id="what" name="what">What they are/How to use them</a></h2> + + <p><code>.htaccess</code> files (or "distributed configuration files") + provide a way to make configuration changes on a per-directory basis. A + file, containing one or more configuration directives, is placed in a + particular document directory, and the directives apply to that + directory, and all subdirectories thereof.</p> + + <p>Note: If you want to call your <code>.htaccess</code> file something + else, you can change the name of the file using the <code><a + href="../mod/core.html#accessfilename">AccessFileName</a></code> + directive. For example, if you would rather call the file + <code>.config</code> then you can put the following in your server + configuration file:</p> + + <blockquote> + <table cellpadding="10"> + <tr> + <td bgcolor="#eeeeee"><code>AccessFileName .config</code> </td> + </tr> + </table> + </blockquote> + + <p>What you can put in these files is determined by the <code><a + href="../mod/core.html#allowoverride">AllowOverride</a></code> + directive. This directive specifies, in categories, what directives + will be honored if they are found in a <code>.htaccess</code> file. If + a directive is permitted in a <code>.htaccess</code> file, the + documentation for that directive will contain an Override section, + specifying what value must be in <code>AllowOverride</code> in order + for that directive to be permitted.</p> + + <p>For example, if you look at the documentation for the <a + href="../mod/core.html#adddefaultcharset">AddDefaultCharset</a> + directive, you will find that it is permitted in <code>.htaccess</code> + files. (See the Context line in the directive summary.) The <a + href="../mod/directive-dict.html#Context">Override</a> line reads + "<code>FileInfo</code>". Thus, you must have at least + "<code>AllowOverride FileInfo</code>" in order for this directive to be + honored in <code>.htaccess</code> files.</p> + + <p>Example:</p> + + <blockquote> + <table> + <tr> + <td><a + href="../mod/directive-dict.html#Context">Context:</a></td> + + <td>server config, virtual host, directory, .htaccess</td> + </tr> + + <tr> + <td><a + href="../mod/directive-dict.html#Override">Override:</a></td> + + <td>FileInfo</td> + </tr> + </table> + </blockquote> + + <p>If you are unsure whether a particular directive is permitted in a + <code>.htaccess</code> file, look at the documentation for that + directive, and check the Context line for ".htaccess."</p> + + <h2><a id="when" name="when">When (not) to use .htaccess files</a></h2> + + <p>In general, you should never use <code>.htaccess</code> files unless + you don't have access to the main server configuration file. There is, + for example, a prevailing misconception that user authentication should + always be done in <code>.htaccess</code> files. This is simply not the + case. You can put user authentication configurations in the main server + configuration, and this is, in fact, the preferred way to do + things.</p> + + <p><code>.htaccess</code> files should be used in a case where the + content providers need to make configuration changes to the server on a + per-directory basis, but do not have root access on the server system. + In the event that the server administrator is not willing to make + frequent configuration changes, it might be desirable to permit + individual users to make these changes in <code>.htaccess</code> files + for themselves. This is particularly true, for example, in cases where + ISPs are hosting multiple user sites on a single machine, and want + their users to be able to alter their configuration.</p> + + <p>However, in general, use of <code>.htaccess</code> files should be + avoided when possible. Any configuration that you would consider + putting in a <code>.htaccess</code> file, can just as effectively be + made in a <a href="../mod/core.html#directory"><Directory></a> + section in your main server configuration file.</p> + + <p>There are two main reasons to avoid the use of + <code>.htaccess</code> files.</p> + + <p>The first of these is performance. When <code>AllowOverride</code> + is set to allow the use of <code>.htaccess</code> files, Apache will + look in every directory for <code>.htaccess</code> files. Thus, + permitting <code>.htaccess</code> files causes a performance hit, + whether or not you actually even use them! Also, the + <code>.htaccess</code> file is loaded every time a document is + requested.</p> + + <p>Further note that Apache must look for <code>.htaccess</code> files + in all higher-level directories, in order to have a full complement of + directives that it must apply. (See section on <a href="#how">how + directives are applied</a>.) Thus, if a file is requested out of a + directory <code>/www/htdocs/example</code>, Apache must look for the + following files:</p> + + <blockquote> + <table cellpadding="10"> + <tr> + <td bgcolor="#eeeeee"><code>/.htaccess<br /> + /www/.htaccess<br /> + /www/htdocs/.htaccess<br /> + /www/htdocs/example/.htaccess</code> </td> + </tr> + </table> + </blockquote> + + <p>And so, for each file access out of that directory, there are 4 + additional file-system accesses, even if none of those files are + present. (Note that this would only be the case if .htaccess files were + enabled for /, which is not usually the case.)</p> + + <p>The second consideration is one of security. You are permitting + users to modify server configuration, which may result in changes over + which you have no control. Carefully consider whether you want to give + your users this privilege.</p> + + <p>Note that it is completely equivalent to put a .htaccess file in a + directory <code>/www/htdocs/example</code> containing a directive, and + to put that same directive in a Directory section <code><Directory + /www/htdocs/example></code> in your main server configuration:</p> + + <p><code>.htaccess</code> file in <code>/www/htdocs/example</code>:</p> + + <blockquote> + <table cellpadding="10"> + <tr> + <td bgcolor="#eeeeee"><code>AddType text/example .exm</code> + </td> + </tr> + </table> + </blockquote> + + <p><code>httpd.conf</code></p> + + <blockquote> + <table cellpadding="10"> + <tr> + <td bgcolor="#eeeeee"><code><Directory + /www/htdocs/example><br /> + AddType text/example .exm<br /> + </Directory></code> </td> + </tr> + </table> + </blockquote> + + <p>However, putting this configuration in your server configuration + file will result in less of a performance hit, as the configuration is + loaded once when Apache starts, rather than every time a file is + requested.</p> + + <p>The use of <code>.htaccess</code> files can be disabled completely + by setting the <code>AllowOverride</code> directive to "none"</p> + + <blockquote> + <table cellpadding="10"> + <tr> + <td bgcolor="#eeeeee"><code>AllowOverride None</code> </td> + </tr> + </table> + </blockquote> + + <h2><a id="how" name="how">How directives are applied</a></h2> + + <p>The configuration directives found in a <code>.htaccess</code> file + are applied to the directory in which the <code>.htaccess</code> file + is found, and to all subdirectories thereof. However, it is important + to also remember that there may have been <code>.htaccess</code> files + in directories higher up. Directives are applied in the order that they + are found. Therefore, a <code>.htaccess</code> file in a particular + directory may override directives found in <code>.htaccess</code> files + found higher up in the directory tree. And those, in turn, may have + overridden directives found yet higher up, or in the main server + configuration file itself.</p> + + <p>Example:</p> + + <p>In the directory <code>/www/htdocs/example1</code> we have a + <code>.htaccess</code> file containing the following:</p> + + <blockquote> + <table cellpadding="10"> + <tr> + <td bgcolor="#eeeeee"><code>Options +ExecCGI</code> </td> + </tr> + </table> + </blockquote> + + <p>(Note: you must have "<code>AllowOverride Options</code>" in effect + to permit the use of the "<code><a + href="../mod/core.html#options">Options</a></code>" directive in + <code>.htaccess</code> files.)</p> + + <p>In the directory <code>/www/htdocs/example1/example2</code> we have + a <code>.htaccess</code> file containing:</p> + + <blockquote> + <table cellpadding="10"> + <tr> + <td bgcolor="#eeeeee"><code>Options Includes</code> </td> + </tr> + </table> + </blockquote> + + <p>Because of this second <code>.htaccess</code> file, in the directory + <code>/www/htdocs/example1/example2</code>, CGI execution is not + permitted, as only <code>Options Includes</code> is in effect, which + completely overrides any earlier setting that may have been in + place.</p> + + <h2><a id="auth" name="auth">Authentication example</a></h2> + + <p>If you jumped directly to this part of the document to find out how + to do authentication, it is important to note one thing. There is a + common misconception that you are required to use + <code>.htaccess</code> files in order to implement password + authentication. This is not the case. Putting authentication directives + in a <code><Directory></code> section, in your main server + configuration file, is the preferred way to implement this, and + <code>.htaccess</code> files should be used only if you don't have + access to the main server configuration file. See above for a + discussion of when you should and should not use <code>.htaccess</code> + files.</p> + + <p>Having said that, if you still think you need to use a + <code>.htaccess</code> file, you may find that a configuration such as + what follows may work for you.</p> + + <p>You must have "<code>AllowOverride AuthConfig</code>" in effect for + these directives to be honored.</p> + + <p><code>.htaccess</code> file contents:</p> + + <blockquote> + <table cellpadding="10"> + <tr> + <td bgcolor="#eeeeee"><code>AuthType Basic<br /> + AuthName "Password Required"<br /> + AuthUserFile /www/passwords/password.file<br /> + AuthGroupFile /www/passwords/group.file<br /> + Require Group admins</code> </td> + </tr> + </table> + </blockquote> + + <p>Note that <code>AllowOverride AuthConfig</code> must be in effect + for these directives to have any effect.</p> + + <p>Please see the <a href="auth.html">authentication tutorial</a> for a + more complete discussion of authentication and authorization.</p> + + <h2><a id="ssi" name="ssi">Server side includes example</a></h2> + + <p>Another common use of <code>.htaccess</code> files is to enable + Server Side Includes for a particular directory. This may be done with + the following configuration directives, placed in a + <code>.htaccess</code> file in the desired directory:</p> + + <blockquote> + <table cellpadding="10"> + <tr> + <td bgcolor="#eeeeee"><code>Options +Includes<br /> + AddType text/html shtml<br /> + AddHandler server-parsed shtml</code> </td> + </tr> + </table> + </blockquote> + + <p>Note that <code>AllowOverride Options</code> and <code>AllowOverride + FileInfo</code> must both be in effect for these directives to have any + effect.</p> + + <p>Please see the <a href="ssi.html">SSI tutorial</a> for a more + complete discussion of server-side includes.</p> + + <h2><a id="cgi" name="cgi">CGI example</a></h2> + + <p>Finally, you may wish to use a <code>.htaccess</code> file to permit + the execution of CGI programs in a particular directory. This may be + implemented with the following configuration:</p> + + <blockquote> + <table cellpadding="10"> + <tr> + <td bgcolor="#eeeeee"><code>Options +ExecCGI<br /> + AddHandler cgi-script cgi pl</code> </td> + </tr> + </table> + </blockquote> + + <p>Alternately, if you wish to have all files in the given directory be + considered to be CGI programs, this may be done with the following + configuration:</p> + + <blockquote> + <table cellpadding="10"> + <tr> + <td bgcolor="#eeeeee"><code>Options +ExecCGI<br /> + SetHandler cgi-script</code> </td> + </tr> + </table> + </blockquote> + + <p>Note that <code>AllowOverride Options</code> must be in effect for + these directives to have any effect.</p> + + <p>Please see the <a href="cgi.html">CGI tutorial</a> for a more + complete discussion of CGI programming and configuration.</p> + + <h2><a id="troubleshoot" name="troubleshoot">Troubleshooting</a></h2> + + <p>When you put configuration directives in a <code>.htaccess</code> + file, and you don't get the desired effect, there are a number of + things that may be going wrong.</p> + + <p>Most commonly, the problem is that <code><a + href="../mod/core.html#allowoverride">AllowOverride</a></code> is not + set such that your configuration directives are being honored. Make + sure that you don't have a <code>AllowOverride None</code> in effect + for the file scope in question. A good test for this is to put garbage + in your <code>.htaccess</code> file and reload. If a server error is + not generated, then you almost certainly have <code>AllowOverride + None</code> in effect.</p> + + <p>If, on the other hand, you are getting server errors when trying to + access documents, check your Apache error log. It will likely tell you + that the directive used in your .htaccess file is not permitted. + Alternately, it may tell you that you had a syntax error, which you + will then need to fix.</p> + </body> +</html> + |