2 Oracle HTTP Server Concepts</titl e> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <meta http-equiv="Content-Language" content="en-US"> <met a http-equiv="Content-Style-Type" content="text/css"> <meta http-equiv="Content-Script-Type" content="text/javascript"> <meta name="r obots" content="all" scheme="http://www.robotstxt.org/"> <meta name="doctitle" content="Oracle® HTTP Server Administrator's Guide 10g Release 1 (10.1)"> <meta name="partno" content="B12255-01"> <link rel="Start" href="../../index.htm" title="Home" type="text/htm l"> <link rel="Copyright" href="../../dcommon/html/cpyr.htm" title="Copyright" type="text/html"> <link rel="Stylesheet" href="../../d common/css/doccd.css" title="Default" type="text/css"> <link rel="Contents" href="toc.htm" title="Contents" type="text/html"> <link r el="Index" href="index.htm" title="Index" type="text/html"> <link rel="Glossary" href="glossary.htm" title="Glossary" type="text/html "> <link rel="Prev" 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table" cellspacing="0" cellpadding="0" align="left" width="90"> <tr> <td align="center" valign="top"><a href="overvie w.htm"><img src="../../dcommon/gifs/larrow.gif" alt="Go to previous page" border="0"><br> <font size="-2">Previous</font></a></td> <t d align="center" valign="top"><a href="fileloc.htm"><img src="../../dcommon/gifs/rarrow.gif" alt="Go to next page" border="0"><br> <f ont size="-2">Next</font></a></td></tr></table></td> <td align="right" valign="top"><a href="../b12255.pdf"><font size="-2">View PDF< /font></a></td></tr></table> <a name="BEGIN"></a></div> <div class="IND"> <a name="1006232"></a>  <h1 class="Title"><font face="Arial, Helvetica, sans-serif" color="#330099">2<br> Oracle HTTP Server Concepts</font></h1>  <a name="1006531"></a> <p class="BP">This chapter introduces you to the Oracle HTTP Server directory structure, an d configuration files, configuration file syntax, modules, and directives.</p> <a name="1006532"></a> <p class="BP">Topics discussed are:</p> <ul class="LB1"> <li class="LB1" type="disc"><a name="1006536"></a><a href="concepts.htm#1006572">Understanding Oracle HTTP Server Directory Structure</a></li> <li class="LB1" type="disc"><a name="1006540"></a><a href="concepts.htm#1007051">Accessing Confi guration Files</a></li> <li class="LB1" type="disc"><a name="1006544"></a><a href="concepts.htm#1006701">Configuration Files Syntax</ a></li> <li class="LB1" type="disc"><a name="1006548"></a><a href="concepts.htm#1006709">Understanding Modules</a></li> <li class="LB 1" type="disc"><a name="1006552"></a><a href="concepts.htm#1006743">Classes of Directives</a></li> <li class="LB1" type="disc"><a nam e="1006556"></a><a href="concepts.htm#1006797">Scope of Directives</a></li> <li class="LB1" type="disc"><a name="1006560"></a><a href ="concepts.htm#1006944">About .htaccess Files</a></li></ul> <a name="1006561"></a> <p class="BP">Documentation from the Apache Softw are Foundation is referenced when applicable.</p> <a name="1006566"></a> <div align="center"> <table class="Note" border="0" width=" 80%" cellpadding="0" cellspacing="0" dir="ltr" summary="This is a layout table to format a note" title="This is a layout table to for mat a note"> <tr class="Note"> <td class="Note"> <hr> <a name="1006564"></a><font face="Arial, Helvetica, sans-serif"><strong class=" NH"><strong class="Bold">Note</strong>:</strong></font> <a name="1006565"></a> <p class="NB">Readers using this guide in PDF or hard copy formats will be unable to access third-party documentation, which Oracle provides in HTML format only. To access the third-part y documentation referenced in this guide, use the HTML version of this guide and click the hyperlinks.</p> <hr></td></tr></table></di v> <p><a name="1006572"></a>  </p> <h2 class="H1"><font face="Arial, Helvetica, sans-serif" color="#330099">Un derstanding Oracle HTTP Server Directory Structure</font></h2>  <a name="1006576"></a> <p class="BP">Oracle HTTP Serve r is installed in the <em><code>ORACLE_HOME</code></em><code>/Apache</code> directory on UNIX or <em><code>ORACLE_HOME</code></em><co de>\Apache</code> directory on Windows for configuring modules. For example, the <code>modplsql</code> folder contains the subdirecto ries necessary to configure and run PL/SQL applications.</p> <a name="1006968"></a> <p class="BP">The <code>Apache</code> directory is located at the top level under the <em><code>ORACLE_HOME</code></em>. It contains subdirectories for configuring modules <code>mod _plsql</code>. It also contains a subdirectory called <code>Apache</code>, which is the base directory of Oracle HTTP Server.</p> <a name="1007051"></a>  <h2 class="H1"><font face="Arial, Helvetica, sans-serif" color="#330099">Accessing Config uration Files</font></h2>  <a name="1006683"></a> <p class="BP">Oracle HTTP Server is configured by placing <em class= "Italic">directives</em>, which are basically instructions, into text configuration files. Most of the configuration files are locate d in:</p> <ul class="LB1"> <li class="LB1" type="disc"><a name="1006684"></a>UNIX: <em><code>ORACLE_HOME</code></em><code>/Apache/Apa che/conf</code></li> <li class="LB1" type="disc"><a name="1006685"></a>Windows: <em><code>ORACLE_HOME</code></em><code>\Apache\Apache \conf</code></li></ul> <a name="1006686"></a> <p class="BP">Some of these files are read only once when the server starts or is relo aded, whereas some files are read every time a related file or directory is requested.</p> <a name="1006687"></a> <p class="BP">The configuration files which are read only once are called <em class="Italic">server-wide</em> configuration files.</p> <a name="1006698 "></a> <div align="center"> <table class="NoteAlso" border="0" width="80%" cellpadding="0" cellspacing="0" dir="ltr" summary="This i s a layout table to format a note" title="This is a layout table to format a note"> <tr class="NoteAlso"> <td class="NoteAlso"><a nam e="1006690"></a><font face="Arial, Helvetica, sans-serif"><strong class="NH">See Also:</strong></font> <a name="1006696"></a> <p cla ss="NB"><a href="conffile.htm#620714">Appendix A, "Oracle HTTP Server Configuration Files"</a><a href="conffile.htm#620714"></a> </p></td></tr></table></div> <p><a name="1006701"></a>  </p> <h2 class="H1"><font face="Arial, Helvetica, sans -serif" color="#330099">Configuration Files Syntax</font></h2>  <a name="1006705"></a> <p class="BP">Oracle HTTP Serve r contains one directive for each line. The back-slash "\" can be used as the last character on a line to indicate that the directive continues onto the next line. There must be no other characters or white space between the back-slash and the end of the line.</p> < a name="1006706"></a> <p class="BP">Directives in the configuration files are case-insensitive, but arguments to directives are ofte n case-sensitive. Lines which begin with the character "#" are considered comments, and are ignored. Comments may not be included on a line after a configuration directive. Blank lines and white space occurring before a directive are ignored, so you may indent direc tives for clarity.</p> <a name="1006709"></a>  <h2 class="H1"><font face="Arial, Helvetica, sans-serif" color= "#330099">Understanding Modules</font></h2>  <a name="1006713"></a> <p class="BP">Oracle HTTP Server is a modular serv er. Modules extend the basic functionality of the Web server, and support integration between Oracle HTTP Server and other Oracle Dat abase components. Oracle HTTP Server includes Apache modules as well as Oracle HTTP Server modules.</p> <a name="1006727"></a> <p cl ass="BP">You can add modules using the <code>LoadModule</code> directive. Following is an example of <code>LoadModule</code> usage.</ p> <pre class="CE"><a name="1006728"></a>LoadModule status_module modules/mod_status.so <a name="1006729"></a> <a name="1006740"></a > </pre> <div> <table summary=""> <tr><td> <a name="1006732"></a><font face="Arial, Helvetica, sans-serif"><strong class="NH">See Al so:</strong></font> <a name="1006739"></a> <a href="confmods.htm#1004903">Chapter 7, "Oracle HTTP Server Modules"</a><a href="confm ods.htm#1004903"></a> </td> </tr> </table> </div> <p><a name="1006743"></a> </p> <h2 class="H1"><font face=" Arial, Helvetica, sans-serif" color="#330099">Classes of Directives</font></h2>  <a name="1006747"></a> <p class="BP"> <a href="concepts.htm#1006754">Table 2-1</a> classifies directives according to the context in which they can be used: global, p er-server, and per-directory.</p> <a name="1006786"></a> <h5 class="TT"><a name="1006786"></a><a name="1006754"></a> <strong><font f ace="Arial, Helvetica, sans-serif"><em>Table 2-1 Classes and Directives </em></font></strong></h5> <table summary="" class="Rul eFormal" border="1" width="100%" cellpadding="3" cellspacing="0" dir="ltr" title=""> <thead> <tr class="Formal"> <th class="Formal" a lign="left" valign="bottom" scope="col"><a name="1006760"></a> <font face="Arial, Helvetica, sans-serif"><strong>Class</strong></font ></th> <th class="Formal" align="left" valign="bottom" scope="col"><a name="1006762"></a> <font face="Arial, Helvetica, sans-serif">< strong>Context</strong></font></th> <th class="Formal" align="left" valign="bottom" scope="col"><a name="1006764"></a> <font face="Ar ial, Helvetica, sans-serif"><strong>Where Used</strong></font></th></tr></thead> <tbody> <tr class="Formal" align="left" valign="top" > <td class="Formal"><a name="1006767"></a> <p class="TB">global</p></td> <td class="Formal"><a name="1006769"></a> <p class="TB">s erver configuration</p></td> <td class="Formal"><a name="1006771"></a> <p class="TB">Inside server configuration files, but only out side of container directives (directives such as <code>VirtualHost</code> that have a start and end directive).</p></td></tr> <tr cla ss="Formal" align="left" valign="top"> <td class="Formal"><a name="1006774"></a> <p class="TB">per-server</p></td> <td class="Formal "><a name="1006776"></a> <p class="TB">server configuration, virtual host</p></td> <td class="Formal"><a name="1006778"></a> <p cla ss="TB">Inside server configuration files, both outside (for the main server) and inside <code>VirtualHost</code> directives.</p></td ></tr> <tr class="Formal" align="left" valign="top"> <td class="Formal"><a name="1006781"></a> <p class="TB">per-directory</p></td> <td class="Formal"><a name="1006783"></a> <p class="TB">server configuration, virtual host, directory</p></td> <td class="Formal"><a name="1006785"></a> <p class="TB">Everywhere; particularly inside the server configuration files.</p></td></tr></tbody></table> <p> <a name="1006794"></a></p> <div align="center"> <table class="Note" border="0" width="80%" cellpadding="0" cellspacing="0" dir="ltr" summary="This is a layout table to format a note" title="This is a layout table to format a note"> <tr class="Note"> <td class="Note" > <hr> <a name="1006789"></a><font face="Arial, Helvetica, sans-serif"><strong class="NH">Note:</strong></font> <a name="1006793"></a > <p class="NB">In <a href="concepts.htm#1006754">Table 2-1</a>, each class is a subset of the class preceding it. For example, directives from the per-directory class can also be used in the per-server and global contexts, and directives from the per-server c lass can be used in the global context.</p> <hr></td></tr></table></div> <p><a name="1006797"></a>  </p> <h2 c lass="H1"><font face="Arial, Helvetica, sans-serif" color="#330099">Scope of Directives</font></h2>  <a name="1006798"> </a> <p class="BP">Directives placed in the main configuration files apply to the entire server. If you wish to change the configura tion for only a part of the server, you can scope your directives by placing them in specific sections.</p> <a name="1006799"></a> < p class="BP">The following section discusses the following types of directives:</p> <ul class="LB1"> <li class="LB1" type="disc"><a n ame="1006803"></a><a href="concepts.htm#1006810">Container Directives</a></li> <li class="LB1" type="disc"><a name="1006807"></a><a h ref="concepts.htm#1006934">Block Directives</a></li></ul> <a name="1006810"></a>  <h3 class="H2"><font face="A rial, Helvetica, sans-serif" color="#330099">Container Directives</font></h3>  <a name="1006811"></a> <p class="BP">Co ntainer directives specify the scope within which directives take effect. The following container directives are discussed in detail in subsequent sections:</p> <ul class="LB1"> <li class="LB1" type="disc"><a name="1006815"></a><a href="concepts.htm#1006850"><Dir ectory></a></li> <li class="LB1" type="disc"><a name="1006819"></a><a href="concepts.htm#1006854"><DirectoryMatch></a></li> <li class="LB1" type="disc"><a name="1006823"></a><a href="concepts.htm#1006861"><Files></a></li> <li class="LB1" type="disc">< a name="1006827"></a><a href="concepts.htm#1006871"><FilesMatch></a></li> <li class="LB1" type="disc"><a name="1006831"></a><a href="concepts.htm#1006878"><Location></a></li> <li class="LB1" type="disc"><a name="1006835"></a><a href="concepts.htm#1006888 "><LocationMatch></a></li> <li class="LB1" type="disc"><a name="1006839"></a><a href="concepts.htm#1006899"><Limit></a></ li> <li class="LB1" type="disc"><a name="1006843"></a><a href="concepts.htm#1006910"><LimitExcept></a></li> <li class="LB1" typ e="disc"><a name="1006847"></a><a href="concepts.htm#1006914"><VirtualHost></a></li></ul> <a name="1006850"></a>  <h4 class="H3"><font face="Arial, Helvetica, sans-serif" color="#330099"><Directory></font></h4>  <a na me="1006851"></a> <p class="BP">It is used to enclose a group of directives that apply only to the named directory and subdirectorie s of that directory. Any directory that is allowed in a directory context may be used. The directory is either the full path to a dir ectory, or a wildcard string. In a wildcard string, ? matches any single character and * matches any sequences of characters. It is i mportant to note that <<code>Directory /</code>> operated on the whole file system, where as <<code>Directory</code> <em><co de>dir</code></em>> refers to absolute directories. <<code>Directory</code>> containers cannot be nested inside each other, but can refer to directories in the document root that are nested.</p> <a name="1006854"></a>  <h4 class="H3"> <font face="Arial, Helvetica, sans-serif" color="#330099"><DirectoryMatch></font></h4>  <a name="1006855"></a> < p class="BP">It should be used when specifying regular expressions, instead of using the tilde form of <<code>Directory</code>> with wildcards in the directory specification. The following two examples have the same result, matching directories starting with < code>web</code> and ending with a number from 1 to 9:</p> <pre class="CE"><a name="1006856"></a><Directory ~/web[1-9]/> <a name ="1006857"></a><DirectoryMatch "/web[1-9]/"> <a name="1006858"></a> </pre> <a name="1006861"></a> <h4 c lass="H3"><font face="Arial, Helvetica, sans-serif" color="#330099"><Files></font></h4>  <a name="1006862"></a> <p class="BP">The <<code>Files</code> <em><code>file</code></em>> and <<code>/Files</code>> directives support access con trol by filename. It is comparable to the <code><a href="concepts.htm#1006850"><Directory></a></code> and <code><a href="concep ts.htm#1006878"><Location></a></code> directives. The directives given within this section can be applied to any object within a base name (the last component of the filename) matching the specified file name. <<code>Files</code>> sections are processed in the order that they appear in the configuration file, after the <<code>Directory</code>> sections, and <code>.htaccess</code > files are read, but before <<code>Location</code>> sections. Note that the <<code>Files</code>> directives can be neste d inside <<code>Directory</code>> sections to restrict the portion of the file system to which they apply.</p> <a name="1006871 "></a>  <h4 class="H3"><font face="Arial, Helvetica, sans-serif" color="#330099"><FilesMatch></font></h4 >  <a name="1006875"></a> <p class="BP">Provides access control by filename, just as the <code><a href="concepts.htm#1 006861"><Files></a></code> directive does. However, it accepts regular expression.</p> <a name="1006878"></a>  <h4 class="H3"><font face="Arial, Helvetica, sans-serif" color="#330099"><Location></font></h4>  <a name=" 1006879"></a> <p class="BP">Limits the application of the directives within a block to those URLs specified, rather than to the phys ical file location like the <code><a href="concepts.htm#1006850"><Directory></a></code> directive. <<code>Location</code>> ; sections are processed in the order that they appear in the configuration file, after the <<code>Directory</code>> sections a nd <code>.htaccess</code> files are read, and after the <code><a href="concepts.htm#1006861"><Files></a></code> sections. << code>Location</code>> accepts wildcard directories and regular expressions with the tilde character.</p> <a name="1006888"></a> <! --TOC=h3-"1006888"--> <h4 class="H3"><font face="Arial, Helvetica, sans-serif" color="#330099"><LocationMatch></font></h4>  <a name="1006892"></a> <p class="BP">Functions in an identical manner to <code><a href="concepts.htm#1006878"><Locatio n></a></code> and you should use it for specifying regular expressions instead of the tilde form of <<code>Location</code>> with wildcards in the location specification.</p> <a name="1006893"></a> <p class="BP">For example:</p> <pre class="CE"><a name="100 6894"></a><LocationMatch "/(extra|special)/data"> <a name="1006895"></a> </pre> <a name="1006896"></a> <p class="BP">matches t he URLs that contained the <code>/extra/data</code> or <code>/special/data</code> sub string.</p> <a name="1006899"></a>  <h4 class="H3"><font face="Arial, Helvetica, sans-serif" color="#330099"><Limit></font></h4>  <a name ="1006900"></a> <p class="BP"><<code>Limit</code> <em><code>method</code></em>> defines a block according to the HTTP method o f the incoming request. The following example limits the application of the directives that follow scripts that use the specified met hod:</p> <pre class="CE"><a name="1006901"></a><Limit POST PUT OPTIONS> <a name="1006902"></a> order deny, allow <a name="1006 903"></a> deny from all <a name="1006904"></a> allow from 127.0.0.192.168 <a name="1006905"></a></Limit> <a name="1006906"></ a> </pre> <a name="1006907"></a> <p class="BP">Generally, <<code>Limit</code>> should not be used unless needed. It is useful only for restricting directives to particular methods. <<code>Limit</code>> is frequently used with other containers, and it is contained in any of them.</p> <a name="1006910"></a>  <h4 class="H3"><font face="Arial, Helvetica, sans-serif " color="#330099"><LimitExcept></font></h4>  <a name="1006911"></a> <p class="BP">Restrict access controls to al l HTTP methods except the named ones.</p> <a name="1006914"></a>  <h4 class="H3"><font face="Arial, Helvetica, sans-serif" color="#330099"><VirtualHost></font></h4>  <a name="1006918"></a> <p class="BP">Oracle HTTP Server has the capabilities to serve many different Web sites simultaneously. Directives can also be scoped by placing them inside <<code >VirtualHost</code>> sections, so that they will only apply to requests for a particular Web site.</p> <a name="1006919"></a> <p class="BP">Virtual host refers to the practice of maintaining more than one server on one machine, as differentiated by their apparen t hostname. For example, it is often desirable for companies sharing a Web server to have their own domain, and Web servers accessibl e as, for example, <code>www.oracle1.com</code> and <code>www.oracle2.com</code>, without requiring you to know any extra path inform ation.</p> <a name="1006925"></a> <p class="BP">Oracle HTTP Server supports both IP-based virtual hosts and name-based virtual hosts . The latter variant is sometimes also called host-based or non-IP virtual hosts.</p> <a name="1006928"></a> <p class="BP">Each virt ual host can have its own name, IP address, and error and access logs. Within a <<code>VirtualHost</code>> container, you can s et up a large number of individual servers run by a single invocation of the Oracle HTTP Server. With virtual hosting, you can specif y a replacement set of the server-level configuration directives that define the main host, and are not allowed in any other containe r.</p> <a name="1006934"></a>  <h3 class="H2"><font face="Arial, Helvetica, sans-serif" color="#330099">Block Directives</font></h3>  <a name="1006935"></a> <p class="BP">Specify a condition which must be true in order for direc tives within to take effect.</p> <a name="1006938"></a> <p class="BP"><<code>IfModule</code>> and <<code>IfDefine</code>> ; are block directives rather than container directives because they do not limit the scope of the directives they contain. They defi ne whether Oracle HTTP Server parses the directives inside the block into its configuration, and the directives are ignored once the server is running.</p> <a name="1006944"></a>  <h2 class="H1"><font face="Arial, Helvetica, sans-serif" color= "#330099">About .htaccess Files</font></h2>  <a name="1006948"></a> <p class="BP">Oracle HTTP Server enables for decen tralized management of configuration through special files places inside the Web tree. The special files are usually called <code>.ht access</code>, but can be specified in the <code>AccessFileName</code> directive. Directives placed in <code>.htaccess</code> files a pply to the directory where you place the file, and all subdirectories. The <code>.htaccess</code> files follow the same syntax as th e main configuration files. Since <code>.htaccess</code> files are read on every request, changes made in these files take immediate effect.</p> <a name="1006950"></a> <p class="BP">The server administrator further controls what directives may be placed in <code>.h taccess</code> files by configuring the <code>AllowOverride</code> directive in the main configuration files.</p> </div><div class="f ooter"> <hr> <table summary="" cellspacing="0" cellpadding="0" width="100%"> <tr> <td style="width: 33%;" align="left"> <table summar y="layout table" cellspacing="0" cellpadding="0" align="left" width="90"> <tr> <td align="center" valign="top"><a href="overview.htm" ><img src="../../dcommon/gifs/larrow.gif" alt="Go to previous page" border="0"><br> <font size="-2">Previous</font></a></td> <td alig n="center" valign="top"><a href="fileloc.htm"><img src="../../dcommon/gifs/rarrow.gif" alt="Go to next page" border="0"><br> <font si ze="-2">Next</font></a></td></tr></table></td> <td style="width: 34%;" align="center"><img src="../../dcommon/gifs/oracle.gif" alt="O racle"><br> <a href="../../dcommon/html/cpyr.htm"><font size="-2">Copyright © 2003 Oracle Corporation</font></a><br> <font size= "-2">All Rights Reserved.</font></td> <td style="width: 33%;" align="right"> <table summary="" cellspacing="0" cellpadding="0" width= "270"> <tr> <td align="center" valign="top"><a href="../../index.htm"><img src="../../dcommon/gifs/prodicon.gif" alt="Go to Documenta tion Home" border="0"><br> <font size="-2">Home</font></a></td> <td align="center" valign="top"><a href="../../nav/portal_3.htm"><img src="../../dcommon/gifs/bookicon.gif" alt="Go to Book List" border="0"><br> <font size="-2">Book List</font></a></td> <td align="cen ter" valign="top"><a href="toc.htm"><img src="../../dcommon/gifs/conticon.gif" alt="Go to Table of Contents" border="0"><br> <font si ze="-2">Contents</font></a></td> <td align="center" valign="top"><a href="index.htm"><img src="../../dcommon/gifs/indxicon.gif" alt=" Go to Index" border="0"><br> <font size="-2">Index</font></a></td> <td align="center" valign="top"><a href="../../mix$101/b12039/toc. htm"><img src="../../dcommon/gifs/mix.gif" alt="Go to Master Index" border="0"><br> <font size="-2">Master Index</font></a></td> <td align="center" valign="top"><a href="../../dcommon/html/feedback.htm"><img src="../../dcommon/gifs/feedback.gif" alt="Go to Feed back page" border="0"><br> <font size="-2">Feedback</font></a></td></tr></table></td></tr></table></div> </body> </html>