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+<title>Log Files - Apache HTTP Server</title>
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+<p class="apache">Apache HTTP Server Version 2.0</p>
+<img alt="" src="./images/feather.gif" /></div>
+<div class="up"><a href="./"><img title="<-" alt="<-" src="./images/left.gif" /></a></div>
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+<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 2.0</a></div><div id="page-content"><div id="preamble"><h1>Log Files</h1>
+<div class="toplang">
+<p><span>Available Languages: </span><a href="./en/logs.html" title="English"> en </a> |
+<a href="./es/logs.html" hreflang="es" rel="alternate" title="Español"> es </a> |
+<a href="./ja/logs.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
+<a href="./ko/logs.html" hreflang="ko" rel="alternate" title="Korean"> ko </a> |
+<a href="./tr/logs.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p>
+</div>
+
+ <p>In order to effectively manage a web server, it is necessary
+ to get feedback about the activity and performance of the
+ server as well as any problems that may be occurring. The Apache
+ HTTP Server provides very comprehensive and flexible logging
+ capabilities. This document describes how to configure its
+ logging capabilities, and how to understand what the logs
+ contain.</p>
+ </div>
+<div id="quickview"><ul id="toc"><li><img alt="" src="./images/down.gif" /> <a href="#security">Security Warning</a></li>
+<li><img alt="" src="./images/down.gif" /> <a href="#errorlog">Error Log</a></li>
+<li><img alt="" src="./images/down.gif" /> <a href="#accesslog">Access Log</a></li>
+<li><img alt="" src="./images/down.gif" /> <a href="#rotation">Log Rotation</a></li>
+<li><img alt="" src="./images/down.gif" /> <a href="#piped">Piped Logs</a></li>
+<li><img alt="" src="./images/down.gif" /> <a href="#virtualhost">Virtual Hosts</a></li>
+<li><img alt="" src="./images/down.gif" /> <a href="#other">Other Log Files</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="security" id="security">Security Warning</a></h2>
+
+
+ <p>Anyone who can write to the directory where Apache is
+ writing a log file can almost certainly gain access to the uid
+ that the server is started as, which is normally root. Do
+ <em>NOT</em> give people write access to the directory the logs
+ are stored in without being aware of the consequences; see the
+ <a href="misc/security_tips.html">security tips</a> document
+ for details.</p>
+
+ <p>In addition, log files may contain information supplied
+ directly by the client, without escaping. Therefore, it is
+ possible for malicious clients to insert control-characters in
+ the log files, so care must be taken in dealing with raw
+ logs.</p>
+ </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
+<div class="section">
+<h2><a name="errorlog" id="errorlog">Error Log</a></h2>
+
+
+ <table class="related"><tr><th>Related Modules</th><th>Related Directives</th></tr><tr><td /><td><ul><li><code class="directive"><a href="./mod/core.html#errorlog">ErrorLog</a></code></li><li><code class="directive"><a href="./mod/core.html#loglevel">LogLevel</a></code></li></ul></td></tr></table>
+
+ <p>The server error log, whose name and location is set by the
+ <code class="directive"><a href="./mod/core.html#errorlog">ErrorLog</a></code> directive, is the
+ most important log file. This is the place where Apache httpd
+ will send diagnostic information and record any errors that it
+ encounters in processing requests. It is the first place to
+ look when a problem occurs with starting the server or with the
+ operation of the server, since it will often contain details of
+ what went wrong and how to fix it.</p>
+
+ <p>The error log is usually written to a file (typically
+ <code>error_log</code> on Unix systems and
+ <code>error.log</code> on Windows and OS/2). On Unix systems it
+ is also possible to have the server send errors to
+ <code>syslog</code> or <a href="#piped">pipe them to a
+ program</a>.</p>
+
+ <p>The format of the error log is relatively free-form and
+ descriptive. But there is certain information that is contained
+ in most error log entries. For example, here is a typical
+ message.</p>
+
+ <div class="example"><p><code>
+ [Wed Oct 11 14:32:52 2000] [error] [client 127.0.0.1]
+ client denied by server configuration:
+ /export/home/live/ap/htdocs/test
+ </code></p></div>
+
+ <p>The first item in the log entry is the date and time of the
+ message. The second item lists the severity of the error being
+ reported. The <code class="directive"><a href="./mod/core.html#loglevel">LogLevel</a></code>
+ directive is used to control the types of errors that are sent
+ to the error log by restricting the severity level. The third
+ item gives the IP address of the client that generated the
+ error. Beyond that is the message itself, which in this case
+ indicates that the server has been configured to deny the
+ client access. The server reports the file-system path (as
+ opposed to the web path) of the requested document.</p>
+
+ <p>A very wide variety of different messages can appear in the
+ error log. Most look similar to the example above. The error
+ log will also contain debugging output from CGI scripts. Any
+ information written to <code>stderr</code> by a CGI script will
+ be copied directly to the error log.</p>
+
+ <p>It is not possible to customize the error log by adding or
+ removing information. However, error log entries dealing with
+ particular requests have corresponding entries in the <a href="#accesslog">access log</a>. For example, the above example
+ entry corresponds to an access log entry with status code 403.
+ Since it is possible to customize the access log, you can
+ obtain more information about error conditions using that log
+ file.</p>
+
+ <p>During testing, it is often useful to continuously monitor
+ the error log for any problems. On Unix systems, you can
+ accomplish this using:</p>
+
+ <div class="example"><p><code>
+ tail -f error_log
+ </code></p></div>
+ </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
+<div class="section">
+<h2><a name="accesslog" id="accesslog">Access Log</a></h2>
+
+
+ <table class="related"><tr><th>Related Modules</th><th>Related Directives</th></tr><tr><td><ul><li><code class="module"><a href="./mod/mod_log_config.html">mod_log_config</a></code></li><li><code class="module"><a href="./mod/mod_setenvif.html">mod_setenvif</a></code></li></ul></td><td><ul><li><code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code></li><li><code class="directive"><a href="./mod/mod_log_config.html#logformat">LogFormat</a></code></li><li><code class="directive"><a href="./mod/mod_setenvif.html#setenvif">SetEnvIf</a></code></li></ul></td></tr></table>
+
+ <p>The server access log records all requests processed by the
+ server. The location and content of the access log are
+ controlled by the <code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code>
+ directive. The <code class="directive"><a href="./mod/mod_log_config.html#logformat">LogFormat</a></code>
+ directive can be used to simplify the selection of
+ the contents of the logs. This section describes how to configure the server
+ to record information in the access log.</p>
+
+ <p>Of course, storing the information in the access log is only
+ the start of log management. The next step is to analyze this
+ information to produce useful statistics. Log analysis in
+ general is beyond the scope of this document, and not really
+ part of the job of the web server itself. For more information
+ about this topic, and for applications which perform log
+ analysis, check the <a href="http://dmoz.org/Computers/Software/Internet/Site_Management/Log_analysis/">
+ Open Directory</a> or <a href="http://dir.yahoo.com/Computers_and_Internet/Software/Internet/World_Wide_Web/Servers/Log_Analysis_Tools/">
+ Yahoo</a>.</p>
+
+ <p>Various versions of Apache httpd have used other modules and
+ directives to control access logging, including
+ mod_log_referer, mod_log_agent, and the
+ <code>TransferLog</code> directive. The <code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code> directive now subsumes
+ the functionality of all the older directives.</p>
+
+ <p>The format of the access log is highly configurable. The format
+ is specified using a format string that looks much like a C-style
+ printf(1) format string. Some examples are presented in the next
+ sections. For a complete list of the possible contents of the
+ format string, see the <code class="module"><a href="./mod/mod_log_config.html">mod_log_config</a></code> <a href="mod/mod_log_config.html#formats">format strings</a>.</p>
+
+ <h3><a name="common" id="common">Common Log Format</a></h3>
+
+
+ <p>A typical configuration for the access log might look as
+ follows.</p>
+
+ <div class="example"><p><code>
+ LogFormat "%h %l %u %t \"%r\" %>s %b" common<br />
+ CustomLog logs/access_log common
+ </code></p></div>
+
+ <p>This defines the <em>nickname</em> <code>common</code> and
+ associates it with a particular log format string. The format
+ string consists of percent directives, each of which tell the
+ server to log a particular piece of information. Literal
+ characters may also be placed in the format string and will be
+ copied directly into the log output. The quote character
+ (<code>"</code>) must be escaped by placing a backslash before
+ it to prevent it from being interpreted as the end of the
+ format string. The format string may also contain the special
+ control characters "<code>\n</code>" for new-line and
+ "<code>\t</code>" for tab.</p>
+
+ <p>The <code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code>
+ directive sets up a new log file using the defined
+ <em>nickname</em>. The filename for the access log is relative to
+ the <code class="directive"><a href="./mod/core.html#serverroot">ServerRoot</a></code> unless it
+ begins with a slash.</p>
+
+ <p>The above configuration will write log entries in a format
+ known as the Common Log Format (CLF). This standard format can
+ be produced by many different web servers and read by many log
+ analysis programs. The log file entries produced in CLF will
+ look something like this:</p>
+
+ <div class="example"><p><code>
+ 127.0.0.1 - frank [10/Oct/2000:13:55:36 -0700] "GET
+ /apache_pb.gif HTTP/1.0" 200 2326
+ </code></p></div>
+
+ <p>Each part of this log entry is described below.</p>
+
+ <dl>
+ <dt><code>127.0.0.1</code> (<code>%h</code>)</dt>
+
+ <dd>This is the IP address of the client (remote host) which
+ made the request to the server. If <code class="directive"><a href="./mod/core.html#hostnamelookups">HostnameLookups</a></code> is
+ set to <code>On</code>, then the server will try to determine
+ the hostname and log it in place of the IP address. However,
+ this configuration is not recommended since it can
+ significantly slow the server. Instead, it is best to use a
+ log post-processor such as <code class="program"><a href="./programs/logresolve.html">logresolve</a></code> to determine
+ the hostnames. The IP address reported here is not
+ necessarily the address of the machine at which the user is
+ sitting. If a proxy server exists between the user and the
+ server, this address will be the address of the proxy, rather
+ than the originating machine.</dd>
+
+ <dt><code>-</code> (<code>%l</code>)</dt>
+
+ <dd>The "hyphen" in the output indicates that the requested
+ piece of information is not available. In this case, the
+ information that is not available is the RFC 1413 identity of
+ the client determined by <code>identd</code> on the clients
+ machine. This information is highly unreliable and should
+ almost never be used except on tightly controlled internal
+ networks. Apache httpd will not even attempt to determine
+ this information unless <code class="directive"><a href="./mod/core.html#identitycheck">IdentityCheck</a></code> is set
+ to <code>On</code>.</dd>
+
+ <dt><code>frank</code> (<code>%u</code>)</dt>
+
+ <dd>This is the userid of the person requesting the document
+ as determined by HTTP authentication. The same value is
+ typically provided to CGI scripts in the
+ <code>REMOTE_USER</code> environment variable. If the status
+ code for the request (see below) is 401, then this value
+ should not be trusted because the user is not yet
+ authenticated. If the document is not password protected,
+ this part will be "<code>-</code>" just like the previous
+ one.</dd>
+
+ <dt><code>[10/Oct/2000:13:55:36 -0700]</code>
+ (<code>%t</code>)</dt>
+
+ <dd>
+ The time that the request was received.
+ The format is:
+
+ <p class="indent">
+ <code>[day/month/year:hour:minute:second zone]<br />
+ day = 2*digit<br />
+ month = 3*letter<br />
+ year = 4*digit<br />
+ hour = 2*digit<br />
+ minute = 2*digit<br />
+ second = 2*digit<br />
+ zone = (`+' | `-') 4*digit</code>
+ </p>
+ It is possible to have the time displayed in another format
+ by specifying <code>%{format}t</code> in the log format
+ string, where <code>format</code> is as in
+ <code>strftime(3)</code> from the C standard library.
+ </dd>
+
+ <dt><code>"GET /apache_pb.gif HTTP/1.0"</code>
+ (<code>\"%r\"</code>)</dt>
+
+ <dd>The request line from the client is given in double
+ quotes. The request line contains a great deal of useful
+ information. First, the method used by the client is
+ <code>GET</code>. Second, the client requested the resource
+ <code>/apache_pb.gif</code>, and third, the client used the
+ protocol <code>HTTP/1.0</code>. It is also possible to log
+ one or more parts of the request line independently. For
+ example, the format string "<code>%m %U%q %H</code>" will log
+ the method, path, query-string, and protocol, resulting in
+ exactly the same output as "<code>%r</code>".</dd>
+
+ <dt><code>200</code> (<code>%>s</code>)</dt>
+
+ <dd>This is the status code that the server sends back to the
+ client. This information is very valuable, because it reveals
+ whether the request resulted in a successful response (codes
+ beginning in 2), a redirection (codes beginning in 3), an
+ error caused by the client (codes beginning in 4), or an
+ error in the server (codes beginning in 5). The full list of
+ possible status codes can be found in the <a href="http://www.w3.org/Protocols/rfc2616/rfc2616.txt">HTTP
+ specification</a> (RFC2616 section 10).</dd>
+
+ <dt><code>2326</code> (<code>%b</code>)</dt>
+
+ <dd>The last part indicates the size of the object returned
+ to the client, not including the response headers. If no
+ content was returned to the client, this value will be
+ "<code>-</code>". To log "<code>0</code>" for no content, use
+ <code>%B</code> instead.</dd>
+ </dl>
+
+
+ <h3><a name="combined" id="combined">Combined Log Format</a></h3>
+
+
+ <p>Another commonly used format string is called the Combined
+ Log Format. It can be used as follows.</p>
+
+ <div class="example"><p><code>
+ LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\"
+ \"%{User-agent}i\"" combined<br />
+ CustomLog log/access_log combined
+ </code></p></div>
+
+ <p>This format is exactly the same as the Common Log Format,
+ with the addition of two more fields. Each of the additional
+ fields uses the percent-directive
+ <code>%{<em>header</em>}i</code>, where <em>header</em> can be
+ any HTTP request header. The access log under this format will
+ look like:</p>
+
+ <div class="example"><p><code>
+ 127.0.0.1 - frank [10/Oct/2000:13:55:36 -0700] "GET
+ /apache_pb.gif HTTP/1.0" 200 2326
+ "http://www.example.com/start.html" "Mozilla/4.08 [en]
+ (Win98; I ;Nav)"
+ </code></p></div>
+
+ <p>The additional fields are:</p>
+
+ <dl>
+ <dt><code>"http://www.example.com/start.html"</code>
+ (<code>\"%{Referer}i\"</code>)</dt>
+
+ <dd>The "Referer" (sic) HTTP request header. This gives the
+ site that the client reports having been referred from. (This
+ should be the page that links to or includes
+ <code>/apache_pb.gif</code>).</dd>
+
+ <dt><code>"Mozilla/4.08 [en] (Win98; I ;Nav)"</code>
+ (<code>\"%{User-agent}i\"</code>)</dt>
+
+ <dd>The User-Agent HTTP request header. This is the
+ identifying information that the client browser reports about
+ itself.</dd>
+ </dl>
+
+
+ <h3><a name="multiple" id="multiple">Multiple Access Logs</a></h3>
+
+
+ <p>Multiple access logs can be created simply by specifying
+ multiple <code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code>
+ directives in the configuration
+ file. For example, the following directives will create three
+ access logs. The first contains the basic CLF information,
+ while the second and third contain referer and browser
+ information. The last two <code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code> lines show how
+ to mimic the effects of the <code>ReferLog</code> and <code>AgentLog</code> directives.</p>
+
+ <div class="example"><p><code>
+ LogFormat "%h %l %u %t \"%r\" %>s %b" common<br />
+ CustomLog logs/access_log common<br />
+ CustomLog logs/referer_log "%{Referer}i -> %U"<br />
+ CustomLog logs/agent_log "%{User-agent}i"
+ </code></p></div>
+
+ <p>This example also shows that it is not necessary to define a
+ nickname with the <code class="directive"><a href="./mod/mod_log_config.html#logformat">LogFormat</a></code> directive. Instead,
+ the log format can be specified directly in the <code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code> directive.</p>
+
+
+ <h3><a name="conditional" id="conditional">Conditional Logs</a></h3>
+
+
+ <p>There are times when it is convenient to exclude certain
+ entries from the access logs based on characteristics of the
+ client request. This is easily accomplished with the help of <a href="env.html">environment variables</a>. First, an
+ environment variable must be set to indicate that the request
+ meets certain conditions. This is usually accomplished with
+ <code class="directive"><a href="./mod/mod_setenvif.html#setenvif">SetEnvIf</a></code>. Then the
+ <code>env=</code> clause of the <code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code> directive is used to
+ include or exclude requests where the environment variable is
+ set. Some examples:</p>
+
+ <div class="example"><p><code>
+ # Mark requests from the loop-back interface<br />
+ SetEnvIf Remote_Addr "127\.0\.0\.1" dontlog<br />
+ # Mark requests for the robots.txt file<br />
+ SetEnvIf Request_URI "^/robots\.txt$" dontlog<br />
+ # Log what remains<br />
+ CustomLog logs/access_log common env=!dontlog
+ </code></p></div>
+
+ <p>As another example, consider logging requests from
+ english-speakers to one log file, and non-english speakers to a
+ different log file.</p>
+
+ <div class="example"><p><code>
+ SetEnvIf Accept-Language "en" english<br />
+ CustomLog logs/english_log common env=english<br />
+ CustomLog logs/non_english_log common env=!english
+ </code></p></div>
+
+ <p>Although we have just shown that conditional logging is very
+ powerful and flexible, it is not the only way to control the
+ contents of the logs. Log files are more useful when they
+ contain a complete record of server activity. It is often
+ easier to simply post-process the log files to remove requests
+ that you do not want to consider.</p>
+
+ </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
+<div class="section">
+<h2><a name="rotation" id="rotation">Log Rotation</a></h2>
+
+
+ <p>On even a moderately busy server, the quantity of
+ information stored in the log files is very large. The access
+ log file typically grows 1 MB or more per 10,000 requests. It
+ will consequently be necessary to periodically rotate the log
+ files by moving or deleting the existing logs. This cannot be
+ done while the server is running, because Apache will continue
+ writing to the old log file as long as it holds the file open.
+ Instead, the server must be <a href="stopping.html">restarted</a> after the log files are
+ moved or deleted so that it will open new log files.</p>
+
+ <p>By using a <em>graceful</em> restart, the server can be
+ instructed to open new log files without losing any existing or
+ pending connections from clients. However, in order to
+ accomplish this, the server must continue to write to the old
+ log files while it finishes serving old requests. It is
+ therefore necessary to wait for some time after the restart
+ before doing any processing on the log files. A typical
+ scenario that simply rotates the logs and compresses the old
+ logs to save space is:</p>
+
+ <div class="example"><p><code>
+ mv access_log access_log.old<br />
+ mv error_log error_log.old<br />
+ apachectl graceful<br />
+ sleep 600<br />
+ gzip access_log.old error_log.old
+ </code></p></div>
+
+ <p>Another way to perform log rotation is using <a href="#piped">piped logs</a> as discussed in the next
+ section.</p>
+ </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
+<div class="section">
+<h2><a name="piped" id="piped">Piped Logs</a></h2>
+
+
+ <p>Apache httpd is capable of writing error and access log
+ files through a pipe to another process, rather than directly
+ to a file. This capability dramatically increases the
+ flexibility of logging, without adding code to the main server.
+ In order to write logs to a pipe, simply replace the filename
+ with the pipe character "<code>|</code>", followed by the name
+ of the executable which should accept log entries on its
+ standard input. Apache will start the piped-log process when
+ the server starts, and will restart it if it crashes while the
+ server is running. (This last feature is why we can refer to
+ this technique as "reliable piped logging".)</p>
+
+ <p>Piped log processes are spawned by the parent Apache httpd
+ process, and inherit the userid of that process. This means
+ that piped log programs usually run as root. It is therefore
+ very important to keep the programs simple and secure.</p>
+
+ <p>One important use of piped logs is to allow log rotation
+ without having to restart the server. The Apache HTTP Server
+ includes a simple program called <code class="program"><a href="./programs/rotatelogs.html">rotatelogs</a></code>
+ for this purpose. For example, to rotate the logs every 24 hours, you
+ can use:</p>
+
+ <div class="example"><p><code>
+ CustomLog "|/usr/local/apache/bin/rotatelogs
+ /var/log/access_log 86400" common
+ </code></p></div>
+
+ <p>Notice that quotes are used to enclose the entire command
+ that will be called for the pipe. Although these examples are
+ for the access log, the same technique can be used for the
+ error log.</p>
+
+ <p>A similar but much more flexible log rotation program
+ called <a href="http://www.cronolog.org/">cronolog</a>
+ is available at an external site.</p>
+
+ <p>As with conditional logging, piped logs are a very powerful
+ tool, but they should not be used where a simpler solution like
+ off-line post-processing is available.</p>
+ </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
+<div class="section">
+<h2><a name="virtualhost" id="virtualhost">Virtual Hosts</a></h2>
+
+
+ <p>When running a server with many <a href="vhosts/">virtual
+ hosts</a>, there are several options for dealing with log
+ files. First, it is possible to use logs exactly as in a
+ single-host server. Simply by placing the logging directives
+ outside the <code class="directive"><a href="./mod/core.html#virtualhost"><VirtualHost></a></code> sections in the
+ main server context, it is possible to log all requests in the
+ same access log and error log. This technique does not allow
+ for easy collection of statistics on individual virtual
+ hosts.</p>
+
+ <p>If <code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code>
+ or <code class="directive"><a href="./mod/core.html#errorlog">ErrorLog</a></code>
+ directives are placed inside a
+ <code class="directive"><a href="./mod/core.html#virtualhost"><VirtualHost></a></code>
+ section, all requests or errors for that virtual host will be
+ logged only to the specified file. Any virtual host which does
+ not have logging directives will still have its requests sent
+ to the main server logs. This technique is very useful for a
+ small number of virtual hosts, but if the number of hosts is
+ very large, it can be complicated to manage. In addition, it
+ can often create problems with <a href="vhosts/fd-limits.html">insufficient file
+ descriptors</a>.</p>
+
+ <p>For the access log, there is a very good compromise. By
+ adding information on the virtual host to the log format
+ string, it is possible to log all hosts to the same log, and
+ later split the log into individual files. For example,
+ consider the following directives.</p>
+
+ <div class="example"><p><code>
+ LogFormat "%v %l %u %t \"%r\" %>s %b"
+ comonvhost<br />
+ CustomLog logs/access_log comonvhost
+ </code></p></div>
+
+ <p>The <code>%v</code> is used to log the name of the virtual
+ host that is serving the request. Then a program like <a href="programs/other.html">split-logfile</a> can be used to
+ post-process the access log in order to split it into one file
+ per virtual host.</p>
+ </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
+<div class="section">
+<h2><a name="other" id="other">Other Log Files</a></h2>
+
+
+ <table class="related"><tr><th>Related Modules</th><th>Related Directives</th></tr><tr><td><ul><li><code class="module"><a href="./mod/mod_cgi.html">mod_cgi</a></code></li><li><code class="module"><a href="./mod/mod_rewrite.html">mod_rewrite</a></code></li></ul></td><td><ul><li><code class="directive"><a href="./mod/mpm_common.html#pidfile">PidFile</a></code></li><li><code class="directive"><a href="./mod/mod_rewrite.html#rewritelog">RewriteLog</a></code></li><li><code class="directive"><a href="./mod/mod_rewrite.html#rewriteloglevel">RewriteLogLevel</a></code></li><li><code class="directive"><a href="./mod/mod_cgi.html#scriptlog">ScriptLog</a></code></li><li><code class="directive"><a href="./mod/mod_cgi.html#scriptlogbuffer">ScriptLogBuffer</a></code></li><li><code class="directive"><a href="./mod/mod_cgi.html#scriptloglength">ScriptLogLength</a></code></li></ul></td></tr></table>
+
+ <h3><a name="pidfile" id="pidfile">PID File</a></h3>
+
+
+ <p>On startup, Apache httpd saves the process id of the parent
+ httpd process to the file <code>logs/httpd.pid</code>. This
+ filename can be changed with the <code class="directive"><a href="./mod/mpm_common.html#pidfile">PidFile</a></code> directive. The
+ process-id is for use by the administrator in restarting and
+ terminating the daemon by sending signals to the parent
+ process; on Windows, use the -k command line option instead.
+ For more information see the <a href="stopping.html">Stopping
+ and Restarting</a> page.</p>
+
+
+ <h3><a name="scriptlog" id="scriptlog">Script Log</a></h3>
+
+
+ <p>In order to aid in debugging, the
+ <code class="directive"><a href="./mod/mod_cgi.html#scriptlog">ScriptLog</a></code> directive
+ allows you to record the input to and output from CGI scripts.
+ This should only be used in testing - not for live servers.
+ More information is available in the <a href="mod/mod_cgi.html">mod_cgi</a> documentation.</p>
+
+
+ <h3><a name="rewritelog" id="rewritelog">Rewrite Log</a></h3>
+
+
+ <p>When using the powerful and complex features of <a href="mod/mod_rewrite.html">mod_rewrite</a>, it is almost
+ always necessary to use the <code class="directive"><a href="./mod/mod_rewrite.html#rewritelog">RewriteLog</a></code> to help
+ in debugging. This log file produces a detailed analysis of how
+ the rewriting engine transforms requests. The level of detail
+ is controlled by the <code class="directive"><a href="./mod/mod_rewrite.html#rewriteloglevel">RewriteLogLevel</a></code> directive.</p>
+
+ </div></div>
+<div class="bottomlang">
+<p><span>Available Languages: </span><a href="./en/logs.html" title="English"> en </a> |
+<a href="./es/logs.html" hreflang="es" rel="alternate" title="Español"> es </a> |
+<a href="./ja/logs.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
+<a href="./ko/logs.html" hreflang="ko" rel="alternate" title="Korean"> ko </a> |
+<a href="./tr/logs.html" hreflang="tr" rel="alternate" title="Türkçe"> 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>
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