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15 <p class="apache">Apache HTTP Server Version 2.3</p>
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19 <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></div><div id="page-content"><div id="preamble"><h1>Log Files</h1>
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27 <p>In order to effectively manage a web server, it is necessary
28 to get feedback about the activity and performance of the
29 server as well as any problems that may be occurring. The Apache
30 HTTP Server provides very comprehensive and flexible logging
31 capabilities. This document describes how to configure its
32 logging capabilities, and how to understand what the logs
35 <div id="quickview"><ul id="toc"><li><img alt="" src="./images/down.gif" /> <a href="#security">Security Warning</a></li>
36 <li><img alt="" src="./images/down.gif" /> <a href="#errorlog">Error Log</a></li>
37 <li><img alt="" src="./images/down.gif" /> <a href="#accesslog">Access Log</a></li>
38 <li><img alt="" src="./images/down.gif" /> <a href="#rotation">Log Rotation</a></li>
39 <li><img alt="" src="./images/down.gif" /> <a href="#piped">Piped Logs</a></li>
40 <li><img alt="" src="./images/down.gif" /> <a href="#virtualhost">Virtual Hosts</a></li>
41 <li><img alt="" src="./images/down.gif" /> <a href="#other">Other Log Files</a></li>
43 <div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
45 <h2><a name="security" id="security">Security Warning</a></h2>
48 <p>Anyone who can write to the directory where Apache is
49 writing a log file can almost certainly gain access to the uid
50 that the server is started as, which is normally root. Do
51 <em>NOT</em> give people write access to the directory the logs
52 are stored in without being aware of the consequences; see the
53 <a href="misc/security_tips.html">security tips</a> document
56 <p>In addition, log files may contain information supplied
57 directly by the client, without escaping. Therefore, it is
58 possible for malicious clients to insert control-characters in
59 the log files, so care must be taken in dealing with raw
61 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
63 <h2><a name="errorlog" id="errorlog">Error Log</a></h2>
66 <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>
68 <p>The server error log, whose name and location is set by the
69 <code class="directive"><a href="./mod/core.html#errorlog">ErrorLog</a></code> directive, is the
70 most important log file. This is the place where Apache httpd
71 will send diagnostic information and record any errors that it
72 encounters in processing requests. It is the first place to
73 look when a problem occurs with starting the server or with the
74 operation of the server, since it will often contain details of
75 what went wrong and how to fix it.</p>
77 <p>The error log is usually written to a file (typically
78 <code>error_log</code> on Unix systems and
79 <code>error.log</code> on Windows and OS/2). On Unix systems it
80 is also possible to have the server send errors to
81 <code>syslog</code> or <a href="#piped">pipe them to a
84 <p>The format of the error log is relatively free-form and
85 descriptive. But there is certain information that is contained
86 in most error log entries. For example, here is a typical
89 <div class="example"><p><code>
90 [Wed Oct 11 14:32:52 2000] [error] [client 127.0.0.1]
91 client denied by server configuration:
92 /export/home/live/ap/htdocs/test
95 <p>The first item in the log entry is the date and time of the
96 message. The second item lists the severity of the error being
97 reported. The <code class="directive"><a href="./mod/core.html#loglevel">LogLevel</a></code>
98 directive is used to control the types of errors that are sent
99 to the error log by restricting the severity level. The third
100 item gives the IP address of the client that generated the
101 error. Beyond that is the message itself, which in this case
102 indicates that the server has been configured to deny the
103 client access. The server reports the file-system path (as
104 opposed to the web path) of the requested document.</p>
106 <p>A very wide variety of different messages can appear in the
107 error log. Most look similar to the example above. The error
108 log will also contain debugging output from CGI scripts. Any
109 information written to <code>stderr</code> by a CGI script will
110 be copied directly to the error log.</p>
112 <p>It is not possible to customize the error log by adding or
113 removing information. However, error log entries dealing with
114 particular requests have corresponding entries in the <a href="#accesslog">access log</a>. For example, the above example
115 entry corresponds to an access log entry with status code 403.
116 Since it is possible to customize the access log, you can
117 obtain more information about error conditions using that log
120 <p>During testing, it is often useful to continuously monitor
121 the error log for any problems. On Unix systems, you can
122 accomplish this using:</p>
124 <div class="example"><p><code>
127 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
128 <div class="section">
129 <h2><a name="accesslog" id="accesslog">Access Log</a></h2>
132 <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>
134 <p>The server access log records all requests processed by the
135 server. The location and content of the access log are
136 controlled by the <code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code>
137 directive. The <code class="directive"><a href="./mod/mod_log_config.html#logformat">LogFormat</a></code>
138 directive can be used to simplify the selection of
139 the contents of the logs. This section describes how to configure the server
140 to record information in the access log.</p>
142 <p>Of course, storing the information in the access log is only
143 the start of log management. The next step is to analyze this
144 information to produce useful statistics. Log analysis in
145 general is beyond the scope of this document, and not really
146 part of the job of the web server itself. For more information
147 about this topic, and for applications which perform log
148 analysis, check the <a href="http://dmoz.org/Computers/Software/Internet/Site_Management/Log_analysis/">
149 Open Directory</a> or <a href="http://dir.yahoo.com/Computers_and_Internet/Software/Internet/World_Wide_Web/Servers/Log_Analysis_Tools/">
152 <p>Various versions of Apache httpd have used other modules and
153 directives to control access logging, including
154 mod_log_referer, mod_log_agent, and the
155 <code>TransferLog</code> directive. The <code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code> directive now subsumes
156 the functionality of all the older directives.</p>
158 <p>The format of the access log is highly configurable. The format
159 is specified using a format string that looks much like a C-style
160 printf(1) format string. Some examples are presented in the next
161 sections. For a complete list of the possible contents of the
162 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>
164 <h3><a name="common" id="common">Common Log Format</a></h3>
167 <p>A typical configuration for the access log might look as
170 <div class="example"><p><code>
171 LogFormat "%h %l %u %t \"%r\" %>s %b" common<br />
172 CustomLog logs/access_log common
175 <p>This defines the <em>nickname</em> <code>common</code> and
176 associates it with a particular log format string. The format
177 string consists of percent directives, each of which tell the
178 server to log a particular piece of information. Literal
179 characters may also be placed in the format string and will be
180 copied directly into the log output. The quote character
181 (<code>"</code>) must be escaped by placing a back-slash before
182 it to prevent it from being interpreted as the end of the
183 format string. The format string may also contain the special
184 control characters "<code>\n</code>" for new-line and
185 "<code>\t</code>" for tab.</p>
187 <p>The <code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code>
188 directive sets up a new log file using the defined
189 <em>nickname</em>. The filename for the access log is relative to
190 the <code class="directive"><a href="./mod/core.html#serverroot">ServerRoot</a></code> unless it
191 begins with a slash.</p>
193 <p>The above configuration will write log entries in a format
194 known as the Common Log Format (CLF). This standard format can
195 be produced by many different web servers and read by many log
196 analysis programs. The log file entries produced in CLF will
197 look something like this:</p>
199 <div class="example"><p><code>
200 127.0.0.1 - frank [10/Oct/2000:13:55:36 -0700] "GET
201 /apache_pb.gif HTTP/1.0" 200 2326
204 <p>Each part of this log entry is described below.</p>
207 <dt><code>127.0.0.1</code> (<code>%h</code>)</dt>
209 <dd>This is the IP address of the client (remote host) which
210 made the request to the server. If <code class="directive"><a href="./mod/core.html#hostnamelookups">HostnameLookups</a></code> is
211 set to <code>On</code>, then the server will try to determine
212 the hostname and log it in place of the IP address. However,
213 this configuration is not recommended since it can
214 significantly slow the server. Instead, it is best to use a
215 log post-processor such as <code class="program"><a href="./programs/logresolve.html">logresolve</a></code> to determine
216 the hostnames. The IP address reported here is not
217 necessarily the address of the machine at which the user is
218 sitting. If a proxy server exists between the user and the
219 server, this address will be the address of the proxy, rather
220 than the originating machine.</dd>
222 <dt><code>-</code> (<code>%l</code>)</dt>
224 <dd>The "hyphen" in the output indicates that the requested
225 piece of information is not available. In this case, the
226 information that is not available is the RFC 1413 identity of
227 the client determined by <code>identd</code> on the clients
228 machine. This information is highly unreliable and should
229 almost never be used except on tightly controlled internal
230 networks. Apache httpd will not even attempt to determine
231 this information unless <code class="directive"><a href="./mod/core.html#identitycheck">IdentityCheck</a></code> is set
232 to <code>On</code>.</dd>
234 <dt><code>frank</code> (<code>%u</code>)</dt>
236 <dd>This is the userid of the person requesting the document
237 as determined by HTTP authentication. The same value is
238 typically provided to CGI scripts in the
239 <code>REMOTE_USER</code> environment variable. If the status
240 code for the request (see below) is 401, then this value
241 should not be trusted because the user is not yet
242 authenticated. If the document is not password protected,
243 this part will be "<code>-</code>" just like the previous
246 <dt><code>[10/Oct/2000:13:55:36 -0700]</code>
247 (<code>%t</code>)</dt>
250 The time that the request was received.
254 <code>[day/month/year:hour:minute:second zone]<br />
256 month = 3*letter<br />
259 minute = 2*digit<br />
260 second = 2*digit<br />
261 zone = (`+' | `-') 4*digit</code>
263 It is possible to have the time displayed in another format
264 by specifying <code>%{format}t</code> in the log format
265 string, where <code>format</code> is as in
266 <code>strftime(3)</code> from the C standard library.
269 <dt><code>"GET /apache_pb.gif HTTP/1.0"</code>
270 (<code>\"%r\"</code>)</dt>
272 <dd>The request line from the client is given in double
273 quotes. The request line contains a great deal of useful
274 information. First, the method used by the client is
275 <code>GET</code>. Second, the client requested the resource
276 <code>/apache_pb.gif</code>, and third, the client used the
277 protocol <code>HTTP/1.0</code>. It is also possible to log
278 one or more parts of the request line independently. For
279 example, the format string "<code>%m %U%q %H</code>" will log
280 the method, path, query-string, and protocol, resulting in
281 exactly the same output as "<code>%r</code>".</dd>
283 <dt><code>200</code> (<code>%>s</code>)</dt>
285 <dd>This is the status code that the server sends back to the
286 client. This information is very valuable, because it reveals
287 whether the request resulted in a successful response (codes
288 beginning in 2), a redirection (codes beginning in 3), an
289 error caused by the client (codes beginning in 4), or an
290 error in the server (codes beginning in 5). The full list of
291 possible status codes can be found in the <a href="http://www.w3.org/Protocols/rfc2616/rfc2616.txt">HTTP
292 specification</a> (RFC2616 section 10).</dd>
294 <dt><code>2326</code> (<code>%b</code>)</dt>
296 <dd>The last part indicates the size of the object returned
297 to the client, not including the response headers. If no
298 content was returned to the client, this value will be
299 "<code>-</code>". To log "<code>0</code>" for no content, use
300 <code>%B</code> instead.</dd>
304 <h3><a name="combined" id="combined">Combined Log Format</a></h3>
307 <p>Another commonly used format string is called the Combined
308 Log Format. It can be used as follows.</p>
310 <div class="example"><p><code>
311 LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\"
312 \"%{User-agent}i\"" combined<br />
313 CustomLog log/access_log combined
316 <p>This format is exactly the same as the Common Log Format,
317 with the addition of two more fields. Each of the additional
318 fields uses the percent-directive
319 <code>%{<em>header</em>}i</code>, where <em>header</em> can be
320 any HTTP request header. The access log under this format will
323 <div class="example"><p><code>
324 127.0.0.1 - frank [10/Oct/2000:13:55:36 -0700] "GET
325 /apache_pb.gif HTTP/1.0" 200 2326
326 "http://www.example.com/start.html" "Mozilla/4.08 [en]
330 <p>The additional fields are:</p>
333 <dt><code>"http://www.example.com/start.html"</code>
334 (<code>\"%{Referer}i\"</code>)</dt>
336 <dd>The "Referer" (sic) HTTP request header. This gives the
337 site that the client reports having been referred from. (This
338 should be the page that links to or includes
339 <code>/apache_pb.gif</code>).</dd>
341 <dt><code>"Mozilla/4.08 [en] (Win98; I ;Nav)"</code>
342 (<code>\"%{User-agent}i\"</code>)</dt>
344 <dd>The User-Agent HTTP request header. This is the
345 identifying information that the client browser reports about
350 <h3><a name="multiple" id="multiple">Multiple Access Logs</a></h3>
353 <p>Multiple access logs can be created simply by specifying
354 multiple <code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code>
355 directives in the configuration
356 file. For example, the following directives will create three
357 access logs. The first contains the basic CLF information,
358 while the second and third contain referer and browser
359 information. The last two <code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code> lines show how
360 to mimic the effects of the <code>ReferLog</code> and <code>AgentLog</code> directives.</p>
362 <div class="example"><p><code>
363 LogFormat "%h %l %u %t \"%r\" %>s %b" common<br />
364 CustomLog logs/access_log common<br />
365 CustomLog logs/referer_log "%{Referer}i -> %U"<br />
366 CustomLog logs/agent_log "%{User-agent}i"
369 <p>This example also shows that it is not necessary to define a
370 nickname with the <code class="directive"><a href="./mod/mod_log_config.html#logformat">LogFormat</a></code> directive. Instead,
371 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>
374 <h3><a name="conditional" id="conditional">Conditional Logs</a></h3>
377 <p>There are times when it is convenient to exclude certain
378 entries from the access logs based on characteristics of the
379 client request. This is easily accomplished with the help of <a href="env.html">environment variables</a>. First, an
380 environment variable must be set to indicate that the request
381 meets certain conditions. This is usually accomplished with
382 <code class="directive"><a href="./mod/mod_setenvif.html#setenvif">SetEnvIf</a></code>. Then the
383 <code>env=</code> clause of the <code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code> directive is used to
384 include or exclude requests where the environment variable is
385 set. Some examples:</p>
387 <div class="example"><p><code>
388 # Mark requests from the loop-back interface<br />
389 SetEnvIf Remote_Addr "127\.0\.0\.1" dontlog<br />
390 # Mark requests for the robots.txt file<br />
391 SetEnvIf Request_URI "^/robots\.txt$" dontlog<br />
392 # Log what remains<br />
393 CustomLog logs/access_log common env=!dontlog
396 <p>As another example, consider logging requests from
397 english-speakers to one log file, and non-english speakers to a
398 different log file.</p>
400 <div class="example"><p><code>
401 SetEnvIf Accept-Language "en" english<br />
402 CustomLog logs/english_log common env=english<br />
403 CustomLog logs/non_english_log common env=!english
406 <p>Although we have just shown that conditional logging is very
407 powerful and flexible, it is not the only way to control the
408 contents of the logs. Log files are more useful when they
409 contain a complete record of server activity. It is often
410 easier to simply post-process the log files to remove requests
411 that you do not want to consider.</p>
413 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
414 <div class="section">
415 <h2><a name="rotation" id="rotation">Log Rotation</a></h2>
418 <p>On even a moderately busy server, the quantity of
419 information stored in the log files is very large. The access
420 log file typically grows 1 MB or more per 10,000 requests. It
421 will consequently be necessary to periodically rotate the log
422 files by moving or deleting the existing logs. This cannot be
423 done while the server is running, because Apache will continue
424 writing to the old log file as long as it holds the file open.
425 Instead, the server must be <a href="stopping.html">restarted</a> after the log files are
426 moved or deleted so that it will open new log files.</p>
428 <p>By using a <em>graceful</em> restart, the server can be
429 instructed to open new log files without losing any existing or
430 pending connections from clients. However, in order to
431 accomplish this, the server must continue to write to the old
432 log files while it finishes serving old requests. It is
433 therefore necessary to wait for some time after the restart
434 before doing any processing on the log files. A typical
435 scenario that simply rotates the logs and compresses the old
436 logs to save space is:</p>
438 <div class="example"><p><code>
439 mv access_log access_log.old<br />
440 mv error_log error_log.old<br />
441 apachectl graceful<br />
443 gzip access_log.old error_log.old
446 <p>Another way to perform log rotation is using <a href="#piped">piped logs</a> as discussed in the next
448 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
449 <div class="section">
450 <h2><a name="piped" id="piped">Piped Logs</a></h2>
453 <p>Apache httpd is capable of writing error and access log
454 files through a pipe to another process, rather than directly
455 to a file. This capability dramatically increases the
456 flexibility of logging, without adding code to the main server.
457 In order to write logs to a pipe, simply replace the filename
458 with the pipe character "<code>|</code>", followed by the name
459 of the executable which should accept log entries on its
460 standard input. Apache will start the piped-log process when
461 the server starts, and will restart it if it crashes while the
462 server is running. (This last feature is why we can refer to
463 this technique as "reliable piped logging".)</p>
465 <p>Piped log processes are spawned by the parent Apache httpd
466 process, and inherit the userid of that process. This means
467 that piped log programs usually run as root. It is therefore
468 very important to keep the programs simple and secure.</p>
470 <p>One important use of piped logs is to allow log rotation
471 without having to restart the server. The Apache HTTP Server
472 includes a simple program called <code class="program"><a href="./programs/rotatelogs.html">rotatelogs</a></code>
473 for this purpose. For example, to rotate the logs every 24 hours, you
476 <div class="example"><p><code>
477 CustomLog "|/usr/local/apache/bin/rotatelogs
478 /var/log/access_log 86400" common
481 <p>Notice that quotes are used to enclose the entire command
482 that will be called for the pipe. Although these examples are
483 for the access log, the same technique can be used for the
486 <p>A similar but much more flexible log rotation program
487 called <a href="http://www.cronolog.org/">cronolog</a>
488 is available at an external site.</p>
490 <p>As with conditional logging, piped logs are a very powerful
491 tool, but they should not be used where a simpler solution like
492 off-line post-processing is available.</p>
493 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
494 <div class="section">
495 <h2><a name="virtualhost" id="virtualhost">Virtual Hosts</a></h2>
498 <p>When running a server with many <a href="vhosts/">virtual
499 hosts</a>, there are several options for dealing with log
500 files. First, it is possible to use logs exactly as in a
501 single-host server. Simply by placing the logging directives
502 outside the <code class="directive"><a href="./mod/core.html#virtualhost"><VirtualHost></a></code> sections in the
503 main server context, it is possible to log all requests in the
504 same access log and error log. This technique does not allow
505 for easy collection of statistics on individual virtual
508 <p>If <code class="directive"><a href="./mod/mod_log_config.html#customlog">CustomLog</a></code>
509 or <code class="directive"><a href="./mod/core.html#errorlog">ErrorLog</a></code>
510 directives are placed inside a
511 <code class="directive"><a href="./mod/core.html#virtualhost"><VirtualHost></a></code>
512 section, all requests or errors for that virtual host will be
513 logged only to the specified file. Any virtual host which does
514 not have logging directives will still have its requests sent
515 to the main server logs. This technique is very useful for a
516 small number of virtual hosts, but if the number of hosts is
517 very large, it can be complicated to manage. In addition, it
518 can often create problems with <a href="vhosts/fd-limits.html">insufficient file
521 <p>For the access log, there is a very good compromise. By
522 adding information on the virtual host to the log format
523 string, it is possible to log all hosts to the same log, and
524 later split the log into individual files. For example,
525 consider the following directives.</p>
527 <div class="example"><p><code>
528 LogFormat "%v %l %u %t \"%r\" %>s %b"
530 CustomLog logs/access_log comonvhost
533 <p>The <code>%v</code> is used to log the name of the virtual
534 host that is serving the request. Then a program like <a href="programs/other.html">split-logfile</a> can be used to
535 post-process the access log in order to split it into one file
536 per virtual host.</p>
537 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
538 <div class="section">
539 <h2><a name="other" id="other">Other Log Files</a></h2>
542 <table class="related"><tr><th>Related Modules</th><th>Related Directives</th></tr><tr><td><ul><li><code class="module"><a href="./mod/mod_logio.html">mod_logio</a></code></li><li><code class="module"><a href="./mod/mod_log_forensic.html">mod_log_forensic</a></code></li><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/mod_log_config.html#logformat">LogFormat</a></code></li><li><code class="directive"><a href="./mod/mod_log_forensic.html#forensiclog">ForensicLog</a></code></li><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>
544 <h3>Logging actual bytes sent and received</h3>
547 <p><code class="module"><a href="./mod/mod_logio.html">mod_logio</a></code> adds in two additional
548 <code class="directive"><a href="./mod/mod_log_config.html#logformat">LogFormat</a></code> fields
549 (%I and %O) that log the actual number of bytes received and sent
553 <h3>Forensic Logging</h3>
556 <p><code class="module"><a href="./mod/mod_log_forensic.html">mod_log_forensic</a></code> provides for forensic logging of
557 client requests. Logging is done before and after processing a
558 request, so the forensic log contains two log lines for each
559 request. The forensic logger is very strict with no customizations.
560 It can be an invaluable debugging and security tool.</p>
563 <h3><a name="pidfile" id="pidfile">PID File</a></h3>
566 <p>On startup, Apache httpd saves the process id of the parent
567 httpd process to the file <code>logs/httpd.pid</code>. This
568 filename can be changed with the <code class="directive"><a href="./mod/mpm_common.html#pidfile">PidFile</a></code> directive. The
569 process-id is for use by the administrator in restarting and
570 terminating the daemon by sending signals to the parent
571 process; on Windows, use the -k command line option instead.
572 For more information see the <a href="stopping.html">Stopping
573 and Restarting</a> page.</p>
576 <h3><a name="scriptlog" id="scriptlog">Script Log</a></h3>
579 <p>In order to aid in debugging, the
580 <code class="directive"><a href="./mod/mod_cgi.html#scriptlog">ScriptLog</a></code> directive
581 allows you to record the input to and output from CGI scripts.
582 This should only be used in testing - not for live servers.
583 More information is available in the <a href="mod/mod_cgi.html">mod_cgi</a> documentation.</p>
586 <h3><a name="rewritelog" id="rewritelog">Rewrite Log</a></h3>
589 <p>When using the powerful and complex features of <a href="mod/mod_rewrite.html">mod_rewrite</a>, it is almost
590 always necessary to use the <code class="directive"><a href="./mod/mod_rewrite.html#rewritelog">RewriteLog</a></code> to help
591 in debugging. This log file produces a detailed analysis of how
592 the rewriting engine transforms requests. The level of detail
593 is controlled by the <code class="directive"><a href="./mod/mod_rewrite.html#rewriteloglevel">RewriteLogLevel</a></code> directive.</p>
596 <div class="bottomlang">
597 <p><span>Available Languages: </span><a href="./en/logs.html" title="English"> en </a> |
598 <a href="./ja/logs.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
599 <a href="./ko/logs.html" hreflang="ko" rel="alternate" title="Korean"> ko </a> |
600 <a href="./tr/logs.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p>
601 </div><div id="footer">
602 <p class="apache">Copyright 2008 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>
603 <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>
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