mod_log_config.html.en revision df855969ca92fac8fecc1e19085904611e3ee06d
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
This file is generated from xml source: DO NOT EDIT
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
-->
<title>mod_log_config - Apache HTTP Server</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" />
<body>
<div id="page-header">
<p class="menu"><a href="/mod/">Modules</a> | <a href="/mod/directives.html">Directives</a> | <a href="/faq/">FAQ</a> | <a href="/glossary.html">Glossary</a> | <a href="/sitemap.html">Sitemap</a></p>
<p class="apache">Apache HTTP Server Version 2.3</p>
<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 2.3</a> > <a href="./">Modules</a></div>
<div id="page-content">
<div id="preamble"><h1>Apache Module mod_log_config</h1>
<div class="toplang">
<p><span>Available Languages: </span><a href="/en/mod/mod_log_config.html" title="English"> en </a> |
<a href="/ja/mod/mod_log_config.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
<a href="/ko/mod/mod_log_config.html" hreflang="ko" rel="alternate" title="Korean"> ko </a> |
<a href="/tr/mod/mod_log_config.html" hreflang="tr" rel="alternate" title="T�rk�e"> tr </a></p>
</div>
<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Logging of the requests made to the server</td></tr>
<tr><th><a href="module-dict.html#ModuleIdentifier">Module�Identifier:</a></th><td>log_config_module</td></tr>
<tr><th><a href="module-dict.html#SourceFile">Source�File:</a></th><td>mod_log_config.c</td></tr></table>
<h3>Summary</h3>
<p>This module provides for flexible logging of client
requests. Logs are written in a customizable format, and may be
written directly to a file, or to an external program.
Conditional logging is provided so that individual requests may
be included or excluded from the logs based on characteristics
of the request.</p>
<p>Three directives are provided by this module:
<code class="directive"><a href="#transferlog">TransferLog</a></code> to create
a log file, <code class="directive"><a href="#logformat">LogFormat</a></code>
to set a custom format, and <code class="directive"><a href="#customlog">CustomLog</a></code> to define a log file and format in one
step. The <code class="directive">TransferLog</code> and <code class="directive">CustomLog</code> directives can be used multiple times in each
server to cause each request to be logged to multiple files.</p>
</div>
<div id="quickview"><h3 class="directives">Directives</h3>
<ul id="toc">
</ul>
<h3>Topics</h3>
<ul id="topics">
</ul><h3>See also</h3>
<ul class="seealso">
</ul></div>
<div class="section">
<h2><a name="formats" id="formats">Custom Log Formats</a></h2>
<p>The format argument to the <code class="directive"><a href="#logformat">LogFormat</a></code> and <code class="directive"><a href="#customlog">CustomLog</a></code> directives is a string. This string is
used to log each request to the log file. It can contain literal
characters copied into the log files and the C-style control
characters "\n" and "\t" to represent new-lines and tabs.
Literal quotes and back-slashes should be escaped with
back-slashes.</p>
<p>The characteristics of the request itself are logged by
placing "<code>%</code>" directives in the format string, which are
replaced in the log file by the values as follows:</p>
<table class="bordered"><tr class="header"><th>Format String</th>
<th>Description</th></tr>
<tr><td><code>%%</code></td>
<td>The percent sign</td></tr>
<tr class="odd"><td><code>%a</code></td>
<td>Remote IP-address</td></tr>
<tr><td><code>%A</code></td>
<td>Local IP-address</td></tr>
<tr class="odd"><td><code>%B</code></td>
<td>Size of response in bytes, excluding HTTP headers.</td></tr>
<tr><td><code>%b</code></td>
a '<code>-</code>' rather than a 0 when no bytes are sent.</td></tr>
<tr class="odd"><td><code>%{<var>VARNAME</var>}C</code></td>
<td>The contents of cookie <var>VARNAME</var> in the request sent
to the server. Only version 0 cookies are fully supported.</td></tr>
<tr><td><code>%D</code></td>
<td>The time taken to serve the request, in microseconds.</td></tr>
<tr class="odd"><td><code>%{<var>VARNAME</var>}e</code></td>
<td>The contents of the environment variable
<var>VARNAME</var></td></tr>
<tr><td><code>%f</code></td>
<td>Filename</td></tr>
<tr class="odd"><td><code>%h</code></td>
<td>Remote host</td></tr>
<tr><td><code>%H</code></td>
<td>The request protocol</td></tr>
<tr class="odd"><td><code>%{<var>VARNAME</var>}i</code></td>
<td>The contents of <code><var>VARNAME</var>:</code> header line(s)
in the request sent to the server. Changes made by other
modules (e.g. <code class="module"><a href="/mod/mod_headers.html">mod_headers</a></code>) affect this.
</td></tr>
<tr><td><code>%k</code></td>
<td>Number of keepalive requests handled on this connection. Interesting if
<code class="directive"><a href="/mod/core.html#keepalive">KeepAlive</a></code> is being used, so that,
for example, a '1' means the first keepalive request after the initial
one, '2' the second, etc...;
otherwise this is always 0 (indicating the initial request).</td></tr>
<tr class="odd"><td><code>%l</code></td>
<td>Remote logname (from identd, if supplied). This will return a
dash unless <code class="module"><a href="/mod/mod_ident.html">mod_ident</a></code> is present and <code class="directive"><a href="/mod/mod_ident.html#identitycheck">IdentityCheck</a></code> is set
<code>On</code>.</td></tr>
<tr><td><code>%m</code></td>
<td>The request method</td></tr>
<tr class="odd"><td><code>%{<var>VARNAME</var>}n</code></td>
<td>The contents of note <var>VARNAME</var> from another
module.</td></tr>
<tr><td><code>%{<var>VARNAME</var>}o</code></td>
<td>The contents of <code><var>VARNAME</var>:</code> header line(s)
in the reply.</td></tr>
<tr class="odd"><td><code>%p</code></td>
<td>The canonical port of the server serving the request</td></tr>
<tr><td><code>%{<var>format</var>}p</code></td>
<td>The canonical port of the server serving the request or the
server's actual port or the client's actual port. Valid formats
are <code>canonical</code>, <code>local</code>, or <code>remote</code>.
</td></tr>
<tr class="odd"><td><code>%P</code></td>
<td>The process ID of the child that serviced the request.</td></tr>
<tr><td><code>%{<var>format</var>}P</code></td>
<td>The process ID or thread id of the child that serviced the
request. Valid formats are <code>pid</code>, <code>tid</code>,
and <code>hextid</code>. <code>hextid</code> requires APR 1.2.0 or
higher.
</td></tr>
<tr class="odd"><td><code>%q</code></td>
<td>The query string (prepended with a <code>?</code> if a query
string exists, otherwise an empty string)</td></tr>
<tr><td><code>%r</code></td>
<td>First line of request</td></tr>
<tr class="odd"><td><code>%s</code></td>
<td>Status. For requests that got internally redirected, this is
the status of the *original* request --- <code>%>s</code>
for the last.</td></tr>
<tr><td><code>%t</code></td>
<td>Time the request was received (standard english
format)</td></tr>
<tr class="odd"><td><code>%{<var>format</var>}t</code></td>
<td>The time, in the form given by format, which should be in
<code>strftime(3)</code> format. (potentially localized)</td></tr>
<tr><td><code>%T</code></td>
<td>The time taken to serve the request, in seconds.</td></tr>
<tr class="odd"><td><code>%u</code></td>
<td>Remote user (from auth; may be bogus if return status
(<code>%s</code>) is 401)</td></tr>
<tr><td><code>%U</code></td>
<td>The URL path requested, not including any query string.</td></tr>
<tr class="odd"><td><code>%v</code></td>
of the server serving the request.</td></tr>
<tr><td><code>%V</code></td>
<td>The server name according to the <code class="directive"><a href="/mod/core.html#usecanonicalname">UseCanonicalName</a></code> setting.</td></tr>
<tr class="odd"><td><code>%X</code></td>
<td>Connection status when response is completed:
<table>
<tr><td><code>X</code> =</td>
<td>connection aborted before the response completed.</td></tr>
<tr><td><code>+</code> =</td>
<td>connection may be kept alive after the response is
sent.</td></tr>
<tr><td><code>-</code> = </td>
<td>connection will be closed after the response is
sent.</td></tr>
</table>
<p>(This directive was <code>%c</code> in late versions of Apache
1.3, but this conflicted with the historical ssl
<code>%{<var>var</var>}c</code> syntax.)</p></td></tr>
<tr><td><code>%I</code></td>
<td>Bytes received, including request and headers, cannot be zero.
You need to enable <code class="module"><a href="/mod/mod_logio.html">mod_logio</a></code> to use this.</td></tr>
<tr class="odd"><td><code>%O</code></td>
<td>Bytes sent, including headers, cannot be zero. You need to
enable <code class="module"><a href="/mod/mod_logio.html">mod_logio</a></code> to use this.</td></tr>
</table>
<h3><a name="modifiers" id="modifiers">Modifiers</a></h3>
<p>Particular items can be restricted to print only for
responses with specific HTTP status codes by placing a
comma-separated list of status codes immediately following the
"%". For example, <code>"%400,501{User-agent}i"</code> logs
<code>User-agent</code> on 400 errors and 501 errors only. For
other status codes, the literal string <code>"-"</code> will be
logged. The status code list may be preceded by a
"<code>!</code>" to indicate negation:
<code>"%!200,304,302{Referer}i"</code> logs <code>Referer</code>
on all requests that do <em>not</em> return one of the three
specified codes.</p>
<p>The modifiers "<" and ">" can be used for requests that
have been internally redirected to choose whether the original
or final (respectively) request should be consulted. By
default, the <code>%</code> directives <code>%s, %U, %T,
%D,</code> and <code>%r</code> look at the original request
while all others look at the final request. So for example,
<code>%>s</code> can be used to record the final status of
the request and <code>%<u</code> can be used to record the
original authenticated user on a request that is internally
redirected to an unauthenticated resource.</p>
<h3><a name="format-notes" id="format-notes">Some Notes</a></h3>
<p>For security reasons, starting with version 2.0.46,
non-printable and other special characters in <code>%r</code>,
<code>%i</code> and <code>%o</code> are escaped using
<code>\x<var>hh</var></code> sequences, where <var>hh</var>
stands for the hexadecimal representation of the raw
byte. Exceptions from this rule are <code>"</code> and
<code>\</code>, which are escaped by prepending a backslash, and
all whitespace characters, which are written in their C-style
notation (<code>\n</code>, <code>\t</code>, etc). In versions
prior to 2.0.46, no escaping was performed on these strings so
you had to be quite careful when dealing with raw log files.</p>
<p>In httpd 2.0, unlike 1.3, the <code>%b</code> and
<code>%B</code> format strings do not represent the number of
bytes sent to the client, but simply the size in bytes of the
HTTP response (which will differ, for instance, if the
connection is aborted, or if SSL is used). The <code>%O</code>
format provided by <code class="module"><a href="/mod/mod_logio.html">mod_logio</a></code> will log the
actual number of bytes sent over the network.</p>
<h3><a name="examples" id="examples">Examples</a></h3>
<p>Some commonly used log format strings are:</p>
<dl>
<dt>Common Log Format (CLF)</dt>
<dd><code>"%h %l %u %t \"%r\" %>s %b"</code></dd>
<dt>Common Log Format with Virtual Host</dt>
<dd><code>"%v %h %l %u %t \"%r\" %>s %b"</code></dd>
<dd><code>"%h %l %u %t \"%r\" %>s %b \"%{Referer}i\"
\"%{User-agent}i\""</code></dd>
<dt>Referer log format</dt>
<dd><code>"%{Referer}i -> %U"</code></dd>
<dt>Agent (Browser) log format</dt>
<dd><code>"%{User-agent}i"</code></dd>
</dl>
<div class="section">
<h2><a name="security" id="security">Security Considerations</a></h2>
document for details on why your security could be compromised
if the directory where logfiles are stored is writable by
anyone other than the user that starts the server.</p>
</div>
<div class="directive-section"><h2><a name="BufferedLogs" id="BufferedLogs">BufferedLogs</a> <a name="bufferedlogs" id="bufferedlogs">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Buffer log entries in memory before writing to disk</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>BufferedLogs On|Off</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>BufferedLogs Off</code></td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in versions 2.0.41 and later.</td></tr>
</table>
<p>The <code class="directive">BufferedLogs</code> directive causes
<code class="module"><a href="/mod/mod_log_config.html">mod_log_config</a></code> to store several log entries in
memory and write them together to disk, rather than writing them
after each request. On some systems, this may result in more
efficient disk access and hence higher performance. It may be
set only once for the entire server; it cannot be configured
per virtual-host.</p>
<div class="note">This directive is experimental and should be used with
caution.</div>
</div>
<div class="directive-section"><h2><a name="CookieLog" id="CookieLog">CookieLog</a> <a name="cookielog" id="cookielog">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets filename for the logging of cookies</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CookieLog <var>filename</var></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>This directive is deprecated.</td></tr>
</table>
<p>The <code class="directive">CookieLog</code> directive sets the
filename for logging of cookies. The filename is relative to the
<code class="directive"><a href="/mod/core.html#serverroot">ServerRoot</a></code>. This directive is
included only for compatibility with <code>mod_cookies</code>,
and is deprecated.</p>
</div>
<div class="directive-section"><h2><a name="CustomLog" id="CustomLog">CustomLog</a> <a name="customlog" id="customlog">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets filename and format of log file</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>CustomLog <var>file</var>|<var>pipe</var>
<var>format</var>|<var>nickname</var>
[env=[!]<var>environment-variable</var>]</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
</table>
<p>The <code class="directive">CustomLog</code> directive is used to
log requests to the server. A log format is specified, and the
logging can optionally be made conditional on request
characteristics using environment variables.</p>
<p>The first argument, which specifies the location to which
the logs will be written, can take one of the following two
types of values:</p>
<dl>
<dt><var>file</var></dt>
<dd>A filename, relative to the <code class="directive"><a href="/mod/core.html#serverroot">ServerRoot</a></code>.</dd>
<dt><var>pipe</var></dt>
<dd>The pipe character "<code>|</code>", followed by the path
to a program to receive the log information on its standard
input.
<div class="warning"><h3>Security:</h3>
<p>If a program is used, then it will be run as the user who
started <code class="program"><a href="/programs/httpd.html">httpd</a></code>. This will be root if the server was
started by root; be sure that the program is secure.</p>
</div>
<div class="warning"><h3>Note</h3>
<p>When entering a file path on non-Unix platforms, care should be taken
to make sure that only forward slashed are used even though the platform
may allow the use of back slashes. In general it is a good idea to always
use forward slashes throughout the configuration files.</p>
</div></dd>
</dl>
<p>The second argument specifies what will be written to the
log file. It can specify either a <var>nickname</var> defined by
a previous <code class="directive"><a href="#logformat">LogFormat</a></code>
directive, or it can be an explicit <var>format</var> string as
described in the <a href="#formats">log formats</a> section.</p>
<p>For example, the following two sets of directives have
exactly the same effect:</p>
<div class="example"><p><code>
# CustomLog with format nickname<br />
LogFormat "%h %l %u %t \"%r\" %>s %b" common<br />
<br />
# CustomLog with explicit format string<br />
CustomLog logs/access_log "%h %l %u %t \"%r\" %>s %b"
</code></p></div>
<p>The third argument is optional and controls whether or
not to log a particular request based on the
presence or absence of a particular variable in the server
environment. If the specified <a href="/env.html">environment
variable</a> is set for the request (or is not set, in the case
of a '<code>env=!<var>name</var></code>' clause), then the
request will be logged.</p>
<p>Environment variables can be set on a per-request
example, if you want to record requests for all GIF
images on your server in a separate logfile but not in your main
log, you can use:</p>
<div class="example"><p><code>
SetEnvIf Request_URI \.gif$ gif-image<br />
CustomLog gif-requests.log common env=gif-image<br />
CustomLog nongif-requests.log common env=!gif-image
</code></p></div>
<p>Or, to reproduce the behavior of the old RefererIgnore
directive, you might use the following:</p>
<div class="example"><p><code>
SetEnvIf Referer example\.com localreferer<br />
CustomLog referer.log referer env=!localreferer
</code></p></div>
</div>
<div class="directive-section"><h2><a name="LogFormat" id="LogFormat">LogFormat</a> <a name="logformat" id="logformat">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Describes a format for use in a log file</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>LogFormat <var>format</var>|<var>nickname</var>
[<var>nickname</var>]</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>LogFormat "%h %l %u %t \"%r\" %>s %b"</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
</table>
<p>This directive specifies the format of the access log
file.</p>
<p>The <code class="directive">LogFormat</code> directive can take one of two
forms. In the first form, where only one argument is specified,
this directive sets the log format which will be used by logs
specified in subsequent <code class="directive">TransferLog</code>
directives. The single argument can specify an explicit
<var>format</var> as discussed in the <a href="#formats">custom log
formats</a> section above. Alternatively, it can use a
<var>nickname</var> to refer to a log format defined in a
previous <code class="directive">LogFormat</code> directive as described
below.</p>
<p>The second form of the <code class="directive">LogFormat</code>
directive associates an explicit <var>format</var> with a
<var>nickname</var>. This <var>nickname</var> can then be used in
subsequent <code class="directive">LogFormat</code> or
<code class="directive"><a href="#customlog">CustomLog</a></code> directives
rather than repeating the entire format string. A
<code class="directive">LogFormat</code> directive that defines a nickname
<strong>does nothing else</strong> -- that is, it <em>only</em>
defines the nickname, it doesn't actually apply the format and make
it the default. Therefore, it will not affect subsequent
<code class="directive"><a href="#transferlog">TransferLog</a></code> directives.
In addition, <code class="directive">LogFormat</code> cannot use one nickname
to define another nickname. Note that the nickname should not contain
percent signs (<code>%</code>).</p>
<div class="example"><h3>Example</h3><p><code>
LogFormat "%v %h %l %u %t \"%r\" %>s %b" vhost_common
</code></p></div>
</div>
<div class="directive-section"><h2><a name="TransferLog" id="TransferLog">TransferLog</a> <a name="transferlog" id="transferlog">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Specify location of a log file</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>TransferLog <var>file</var>|<var>pipe</var></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
</table>
<p>This directive has exactly the same arguments and effect as
the <code class="directive"><a href="#customlog">CustomLog</a></code>
directive, with the exception that it does not allow the log format
to be specified explicitly or for conditional logging of requests.
Instead, the log format is determined by the most recently specified
<code class="directive"><a href="#logformat">LogFormat</a></code> directive
which does not define a nickname. Common Log Format is used if no
other format has been specified.</p>
<div class="example"><h3>Example</h3><p><code>
LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-agent}i\""<br />
TransferLog logs/access_log
</code></p></div>
</div>
</div>
<div class="bottomlang">
<p><span>Available Languages: </span><a href="/en/mod/mod_log_config.html" title="English"> en </a> |
<a href="/ja/mod/mod_log_config.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
<a href="/ko/mod/mod_log_config.html" hreflang="ko" rel="alternate" title="Korean"> ko </a> |
<a href="/tr/mod/mod_log_config.html" hreflang="tr" rel="alternate" title="T�rk�e"> tr </a></p>
</div><div id="footer">
<p class="apache">Copyright 2009 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
<p class="menu"><a href="/mod/">Modules</a> | <a href="/mod/directives.html">Directives</a> | <a href="/faq/">FAQ</a> | <a href="/glossary.html">Glossary</a> | <a href="/sitemap.html">Sitemap</a></p></div>
</body></html>