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diff --git a/docs/manual/mod/mod_ext_filter.html.en b/docs/manual/mod/mod_ext_filter.html.en new file mode 100644 index 0000000..3ec3de5 --- /dev/null +++ b/docs/manual/mod/mod_ext_filter.html.en @@ -0,0 +1,362 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head> +<meta content="text/html; charset=UTF-8" http-equiv="Content-Type" /> +<!-- + XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX + This file is generated from xml source: DO NOT EDIT + XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX + --> +<title>mod_ext_filter - Apache HTTP Server Version 2.4</title> +<link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" /> +<link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" /> +<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" /><link rel="stylesheet" type="text/css" href="../style/css/prettify.css" /> +<script src="../style/scripts/prettify.min.js" type="text/javascript"> +</script> + +<link href="../images/favicon.ico" rel="shortcut icon" /></head> +<body> +<div id="page-header"> +<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="http://wiki.apache.org/httpd/FAQ">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p> +<p class="apache">Apache HTTP Server Version 2.4</p> +<img alt="" src="../images/feather.png" /></div> +<div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div> +<div id="path"> +<a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.4</a> > <a href="./">Modules</a></div> +<div id="page-content"> +<div id="preamble"><h1>Apache Module mod_ext_filter</h1> +<div class="toplang"> +<p><span>Available Languages: </span><a href="../en/mod/mod_ext_filter.html" title="English"> en </a> | +<a href="../fr/mod/mod_ext_filter.html" hreflang="fr" rel="alternate" title="Français"> fr </a> | +<a href="../ja/mod/mod_ext_filter.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> | +<a href="../ko/mod/mod_ext_filter.html" hreflang="ko" rel="alternate" title="Korean"> ko </a></p> +</div> +<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Pass the response body through an external program before +delivery to the client</td></tr> +<tr><th><a href="module-dict.html#Status">Status:</a></th><td>Extension</td></tr> +<tr><th><a href="module-dict.html#ModuleIdentifier">Module Identifier:</a></th><td>ext_filter_module</td></tr> +<tr><th><a href="module-dict.html#SourceFile">Source File:</a></th><td>mod_ext_filter.c</td></tr></table> +<h3>Summary</h3> + + <p><code class="module"><a href="../mod/mod_ext_filter.html">mod_ext_filter</a></code> presents a simple and familiar + programming model for <a href="../filter.html">filters</a>. With + this module, a program which reads from stdin and writes to stdout + (i.e., a Unix-style filter command) can be a filter for + Apache. This filtering mechanism is much slower than using a + filter which is specially written for the Apache API and runs + inside of the Apache server process, but it does have the + following benefits:</p> + + <ul> + <li>the programming model is much simpler</li> + + <li>any programming/scripting language can be used, provided + that it allows the program to read from standard input and + write to standard output</li> + + <li>existing programs can be used unmodified as Apache + filters</li> + </ul> + + <p>Even when the performance characteristics are not suitable + for production use, <code class="module"><a href="../mod/mod_ext_filter.html">mod_ext_filter</a></code> can be used as + a prototype environment for filters.</p> + +</div> +<div id="quickview"><a href="https://www.apache.org/foundation/contributing.html" class="badge"><img src="https://www.apache.org/images/SupportApache-small.png" alt="Support Apache!" /></a><h3>Topics</h3> +<ul id="topics"> +<li><img alt="" src="../images/down.gif" /> <a href="#examples">Examples</a></li> +</ul><h3 class="directives">Directives</h3> +<ul id="toc"> +<li><img alt="" src="../images/down.gif" /> <a href="#extfilterdefine">ExtFilterDefine</a></li> +<li><img alt="" src="../images/down.gif" /> <a href="#extfilteroptions">ExtFilterOptions</a></li> +</ul> +<h3>Bugfix checklist</h3><ul class="seealso"><li><a href="https://www.apache.org/dist/httpd/CHANGES_2.4">httpd changelog</a></li><li><a href="https://bz.apache.org/bugzilla/buglist.cgi?bug_status=__open__&list_id=144532&product=Apache%20httpd-2&query_format=specific&order=changeddate%20DESC%2Cpriority%2Cbug_severity&component=mod_ext_filter">Known issues</a></li><li><a href="https://bz.apache.org/bugzilla/enter_bug.cgi?product=Apache%20httpd-2&component=mod_ext_filter">Report a bug</a></li></ul><h3>See also</h3> +<ul class="seealso"> +<li><a href="../filter.html">Filters</a></li> +<li><a href="#comments_section">Comments</a></li></ul></div> +<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="section"> +<h2><a name="examples" id="examples">Examples</a></h2> + + <h3>Generating HTML from some other type of response</h3> + <pre class="prettyprint lang-config"># mod_ext_filter directive to define a filter +# to HTML-ize text/c files using the external +# program /usr/bin/enscript, with the type of +# the result set to text/html +ExtFilterDefine c-to-html mode=output \ + intype=text/c outtype=text/html \ + cmd="/usr/bin/enscript --color -w html -Ec -o -" + +<Directory "/export/home/trawick/apacheinst/htdocs/c"> + # core directive to cause the new filter to + # be run on output + SetOutputFilter c-to-html + + # mod_mime directive to set the type of .c + # files to text/c + AddType text/c .c +</Directory></pre> + + + + <h3>Implementing a content encoding filter</h3> + <p>Note: this gzip example is just for the purposes of illustration. + Please refer to <code class="module"><a href="../mod/mod_deflate.html">mod_deflate</a></code> for a practical + implementation.</p> + + <pre class="prettyprint lang-config"># mod_ext_filter directive to define the external filter +ExtFilterDefine gzip mode=output cmd=/bin/gzip + +<Location "/gzipped"> + + # core directive to cause the gzip filter to be + # run on output + SetOutputFilter gzip + + # mod_headers directive to add + # "Content-Encoding: gzip" header field + Header set Content-Encoding gzip +</Location></pre> + + + + <h3>Slowing down the server</h3> + <pre class="prettyprint lang-config"># mod_ext_filter directive to define a filter +# which runs everything through cat; cat doesn't +# modify anything; it just introduces extra pathlength +# and consumes more resources +ExtFilterDefine slowdown mode=output cmd=/bin/cat \ + preservescontentlength + +<Location "/"> + # core directive to cause the slowdown filter to + # be run several times on output + # + SetOutputFilter slowdown;slowdown;slowdown +</Location></pre> + + + + <h3>Using sed to replace text in the response</h3> + <pre class="prettyprint lang-config"># mod_ext_filter directive to define a filter which +# replaces text in the response +# +ExtFilterDefine fixtext mode=output intype=text/html \ + cmd="/bin/sed s/verdana/arial/g" + +<Location "/"> + # core directive to cause the fixtext filter to + # be run on output + SetOutputFilter fixtext +</Location></pre> + + +<div class="note"> +<p>You can do the same thing using <code class="module"><a href="../mod/mod_substitute.html">mod_substitute</a></code> +without invoking an external process.</p> +</div> + + + <h3>Tracing another filter</h3> + <pre class="prettyprint lang-config"># Trace the data read and written by mod_deflate +# for a particular client (IP 192.168.1.31) +# experiencing compression problems. +# This filter will trace what goes into mod_deflate. +ExtFilterDefine tracebefore \ + cmd="/bin/tracefilter.pl /tmp/tracebefore" \ + EnableEnv=trace_this_client + +# This filter will trace what goes after mod_deflate. +# Note that without the ftype parameter, the default +# filter type of AP_FTYPE_RESOURCE would cause the +# filter to be placed *before* mod_deflate in the filter +# chain. Giving it a numeric value slightly higher than +# AP_FTYPE_CONTENT_SET will ensure that it is placed +# after mod_deflate. +ExtFilterDefine traceafter \ + cmd="/bin/tracefilter.pl /tmp/traceafter" \ + EnableEnv=trace_this_client ftype=21 + +<Directory "/usr/local/docs"> + SetEnvIf Remote_Addr 192.168.1.31 trace_this_client + SetOutputFilter tracebefore;deflate;traceafter +</Directory></pre> + + + <div class="example"><h3>Here is the filter which traces the data:</h3><pre class="prettyprint lang-perl">#!/usr/local/bin/perl -w +use strict; + +open(SAVE, ">$ARGV[0]") + or die "can't open $ARGV[0]: $?"; + +while (<STDIN>) { + print SAVE $_; + print $_; +} + +close(SAVE);</pre> +</div> + +</div> +<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="directive-section"><h2><a name="ExtFilterDefine" id="ExtFilterDefine">ExtFilterDefine</a> <a name="extfilterdefine" id="extfilterdefine">Directive</a></h2> +<table class="directive"> +<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Define an external filter</td></tr> +<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ExtFilterDefine <var>filtername</var> <var>parameters</var></code></td></tr> +<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr> +<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr> +<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_ext_filter</td></tr> +</table> + <p>The <code class="directive">ExtFilterDefine</code> directive defines the + characteristics of an external filter, including the program to + run and its arguments.</p> + + <p><var>filtername</var> specifies the name of the filter being + defined. This name can then be used in <code class="directive"><a href="../mod/core.html#setoutputfilter">SetOutputFilter</a></code> + directives. It must be unique among all registered filters. + <em>At the present time, no error is reported by the + register-filter API, so a problem with duplicate names isn't + reported to the user.</em></p> + + <p>Subsequent parameters can appear in any order and define the + external command to run and certain other characteristics. The + only required parameter is <code>cmd=</code>. These parameters + are:</p> + + <dl> + <dt><code>cmd=<var>cmdline</var></code></dt> + + <dd>The <code>cmd=</code> keyword allows you to specify the + external command to run. If there are arguments after the + program name, the command line should be surrounded in + quotation marks (<em>e.g.</em>, <code>cmd="<var>/bin/mypgm</var> + <var>arg1</var> <var>arg2</var>"</code>.) Normal shell quoting is + not necessary since the program is run directly, bypassing the shell. + Program arguments are blank-delimited. A backslash can be used to + escape blanks which should be part of a program argument. Any + backslashes which are part of the argument must be escaped with + backslash themselves. In addition to the standard CGI environment + variables, DOCUMENT_URI, DOCUMENT_PATH_INFO, and + QUERY_STRING_UNESCAPED will also be set for the program.</dd> + + <dt><code>mode=<var>mode</var></code></dt> + + <dd>Use <code>mode=output</code> (the default) for filters which + process the response. Use <code>mode=input</code> for filters + which process the request. <code>mode=input</code> is available + in Apache 2.1 and later.</dd> + + <dt><code>intype=<var>imt</var></code></dt> + + <dd>This parameter specifies the internet media type (<em>i.e.</em>, + MIME type) of documents which should be filtered. By default, + all documents are filtered. If <code>intype=</code> is + specified, the filter will be disabled for documents of other + types.</dd> + + <dt><code>outtype=<var>imt</var></code></dt> + + <dd>This parameter specifies the internet media type (<em>i.e.</em>, + MIME type) of filtered documents. It is useful when the + filter changes the internet media type as part of the + filtering operation. By default, the internet media type is + unchanged.</dd> + + <dt><code>PreservesContentLength</code></dt> + + <dd>The <code>PreservesContentLength</code> keyword specifies + that the filter preserves the content length. This is not the + default, as most filters change the content length. In the + event that the filter doesn't modify the length, this keyword + should be specified.</dd> + + <dt><code>ftype=<var>filtertype</var></code></dt> + + <dd>This parameter specifies the numeric value for filter type + that the filter should be registered as. The default value, + AP_FTYPE_RESOURCE, is sufficient in most cases. If the filter + needs to operate at a different point in the filter chain than + resource filters, then this parameter will be necessary. See + the AP_FTYPE_foo definitions in util_filter.h for appropriate + values.</dd> + + <dt><code>disableenv=<var>env</var></code></dt> + + <dd>This parameter specifies the name of an environment variable + which, if set, will disable the filter.</dd> + + <dt><code>enableenv=<var>env</var></code></dt> + + <dd>This parameter specifies the name of an environment variable + which must be set, or the filter will be disabled.</dd> + </dl> + +</div> +<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="directive-section"><h2><a name="ExtFilterOptions" id="ExtFilterOptions">ExtFilterOptions</a> <a name="extfilteroptions" id="extfilteroptions">Directive</a></h2> +<table class="directive"> +<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configure <code class="module"><a href="../mod/mod_ext_filter.html">mod_ext_filter</a></code> options</td></tr> +<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ExtFilterOptions <var>option</var> [<var>option</var>] ...</code></td></tr> +<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ExtFilterOptions NoLogStderr</code></td></tr> +<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory</td></tr> +<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr> +<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_ext_filter</td></tr> +</table> + <p>The <code class="directive">ExtFilterOptions</code> directive specifies + special processing options for <code class="module"><a href="../mod/mod_ext_filter.html">mod_ext_filter</a></code>. + <var>Option</var> can be one of</p> + + <dl> + <dt><code>LogStderr | NoLogStderr</code></dt> + + <dd>The <code>LogStderr</code> keyword specifies that + messages written to standard error by the external filter + program will be saved in the Apache error log. + <code>NoLogStderr</code> disables this feature.</dd> + + <dt><code>Onfail=[abort|remove]</code></dt> + <dd>Determines how to proceed if the external filter program + cannot be started. With <code>abort</code> (the default value) + the request will be aborted. With <code>remove</code>, the + filter is removed and the request continues without it.</dd> + </dl> + + <pre class="prettyprint lang-config">ExtFilterOptions LogStderr</pre> + + + <p>Messages written to the filter's standard error will be stored + in the Apache error log.</p> + +</div> +</div> +<div class="bottomlang"> +<p><span>Available Languages: </span><a href="../en/mod/mod_ext_filter.html" title="English"> en </a> | +<a href="../fr/mod/mod_ext_filter.html" hreflang="fr" rel="alternate" title="Français"> fr </a> | +<a href="../ja/mod/mod_ext_filter.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> | +<a href="../ko/mod/mod_ext_filter.html" hreflang="ko" rel="alternate" title="Korean"> ko </a></p> +</div><div class="top"><a href="#page-header"><img src="../images/up.gif" alt="top" /></a></div><div class="section"><h2><a id="comments_section" name="comments_section">Comments</a></h2><div class="warning"><strong>Notice:</strong><br />This is not a Q&A section. 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