From 5dff2d61cc1c27747ee398e04d8e02843aabb1f8 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Tue, 7 May 2024 04:04:06 +0200 Subject: Adding upstream version 2.4.38. Signed-off-by: Daniel Baumann --- docs/manual/mod/mod_log_config.html.en | 603 +++++++++++++++++++++++++++++++++ 1 file changed, 603 insertions(+) create mode 100644 docs/manual/mod/mod_log_config.html.en (limited to 'docs/manual/mod/mod_log_config.html.en') diff --git a/docs/manual/mod/mod_log_config.html.en b/docs/manual/mod/mod_log_config.html.en new file mode 100644 index 0000000..d2cca1a --- /dev/null +++ b/docs/manual/mod/mod_log_config.html.en @@ -0,0 +1,603 @@ + + + + + +mod_log_config - Apache HTTP Server Version 2.4 + + + + + + + +
+

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+

Apache HTTP Server Version 2.4

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+
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+ +
+

Apache Module mod_log_config

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+

Available Languages:  en  | + fr  | + ja  | + ko  | + tr 

+
+ + + +
Description:Logging of the requests made to the server
Status:Base
Module Identifier:log_config_module
Source File:mod_log_config.c
+

Summary

+ +

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.

+ +

Three directives are provided by this module: + TransferLog to create + a log file, LogFormat + to set a custom format, and CustomLog to define a log file and format in one + step. The TransferLog and CustomLog directives can be used multiple times in each + server to cause each request to be logged to multiple files.

+
+ +
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+
+

Custom Log Formats

+ +

The format argument to the LogFormat and CustomLog 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 backslashes should be escaped with + backslashes.

+ +

The characteristics of the request itself are logged by + placing "%" directives in the format string, which are + replaced in the log file by the values as follows:

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Format StringDescription
%%The percent sign.
%aClient IP address of the request (see the + mod_remoteip module).
%{c}aUnderlying peer IP address of the connection (see the + mod_remoteip module).
%ALocal IP-address.
%BSize of response in bytes, excluding HTTP headers.
%bSize of response in bytes, excluding HTTP headers. In CLF format, i.e. + a '-' rather than a 0 when no bytes are sent.
%{VARNAME}CThe contents of cookie VARNAME in the request sent + to the server. Only version 0 cookies are fully supported.
%DThe time taken to serve the request, in microseconds.
%{VARNAME}eThe contents of the environment variable + VARNAME.
%fFilename.
%hRemote hostname. Will log the IP address if HostnameLookups is set to + Off, which is the default. If it logs the hostname + for only a few hosts, you probably have access control + directives mentioning them by name. See the Require host + documentation.
%HThe request protocol.
%{VARNAME}iThe contents of VARNAME: header line(s) + in the request sent to the server. Changes made by other + modules (e.g. mod_headers) affect this. If you're + interested in what the request header was prior to when most + modules would have modified it, use mod_setenvif + to copy the header into an internal environment variable and log + that value with the %{VARNAME}e described + above. +
%kNumber of keepalive requests handled on this connection. Interesting if + KeepAlive 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).
%lRemote logname (from identd, if supplied). This will return a + dash unless mod_ident is present and IdentityCheck is set + On.
%LThe request log ID from the error log (or '-' if nothing has been + logged to the error log for this request). Look for the + matching error log line to see what request caused what error.
%mThe request method.
%{VARNAME}nThe contents of note VARNAME from another + module.
%{VARNAME}oThe contents of VARNAME: header line(s) + in the reply.
%pThe canonical port of the server serving the request.
%{format}pThe canonical port of the server serving the request, or the + server's actual port, or the client's actual port. Valid formats + are canonical, local, or remote. +
%PThe process ID of the child that serviced the request.
%{format}PThe process ID or thread ID of the child that serviced the + request. Valid formats are pid, tid, + and hextid. hextid requires APR 1.2.0 or + higher. +
%qThe query string (prepended with a ? if a query + string exists, otherwise an empty string).
%rFirst line of request.
%RThe handler generating the response (if any).
%sStatus. For requests that have been internally redirected, this is + the status of the original request. Use %>s + for the final status.
%tTime the request was received, in the format [18/Sep/2011:19:18:28 -0400]. + The last number indicates the timezone offset from GMT
%{format}tThe time, in the form given by format, which should be in + an extended strftime(3) format (potentially localized). + If the format starts with begin: (default) the time is taken + at the beginning of the request processing. If it starts with + end: it is the time when the log entry gets written, + close to the end of the request processing. In addition to the formats + supported by strftime(3), the following format tokens are + supported: + + + + + + +
secnumber of seconds since the Epoch
msecnumber of milliseconds since the Epoch
usecnumber of microseconds since the Epoch
msec_fracmillisecond fraction
usec_fracmicrosecond fraction
+ These tokens can not be combined with each other or strftime(3) + formatting in the same format string. You can use multiple + %{format}t tokens instead. +
%TThe time taken to serve the request, in seconds.
%{UNIT}TThe time taken to serve the request, in a time unit given by + UNIT. Valid units are ms for milliseconds, + us for microseconds, and s for seconds. + Using s gives the same result as %T + without any format; using us gives the same result + as %D. Combining %T with a unit is + available in 2.4.13 and later.
%uRemote user if the request was authenticated. May be bogus if return status + (%s) is 401 (unauthorized).
%UThe URL path requested, not including any query string.
%vThe canonical ServerName + of the server serving the request.
%VThe server name according to the UseCanonicalName setting.
%XConnection status when response is completed: + + + + + + + + + +
X =Connection aborted before the response completed.
+ =Connection may be kept alive after the response is + sent.
- = Connection will be closed after the response is + sent.
+ +
%IBytes received, including request and headers. Cannot be zero. + You need to enable mod_logio to use this.
%OBytes sent, including headers. May be zero in rare cases + such as when a request is aborted before a response is sent. + You need to enable mod_logio to use this.
%SBytes transferred (received and sent), including request and headers, + cannot be zero. This is the combination of %I and %O. You need to + enable mod_logio to use this.
%{VARNAME}^tiThe contents of VARNAME: trailer line(s) + in the request sent to the server.
%{VARNAME}^toThe contents of VARNAME: trailer line(s) + in the response sent from the server.
+ +

Modifiers

+ +

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 + "%". The status code list may be preceded by a "!" to + indicate negation.

+ + + + + + + + +
Format StringMeaning
%400,501{User-agent}iLogs User-agent on 400 errors and 501 errors only. For + other status codes, the literal string "-" will be + logged.
%!200,304,302{Referer}iLogs Referer on all requests that do + not return one of the three specified codes, + "-" otherwise. +
+ +

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 % directives %s, %U, %T, + %D, and %r look at the original request + while all others look at the final request. So for example, + %>s can be used to record the final status of + the request and %<u can be used to record the + original authenticated user on a request that is internally + redirected to an unauthenticated resource.

+ + + +

Format Notes

+ +

For security reasons, starting with version 2.0.46, + non-printable and other special characters in %r, + %i and %o are escaped using + \xhh sequences, where hh + stands for the hexadecimal representation of the raw + byte. Exceptions from this rule are " and + \, which are escaped by prepending a backslash, and + all whitespace characters, which are written in their C-style + notation (\n, \t, 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.

+ +

Since httpd 2.0, unlike 1.3, the %b and + %B 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 %O + format provided by mod_logio will log the + actual number of bytes sent over the network.

+ +
+

Note: mod_cache is implemented as a + quick-handler and not as a standard handler. Therefore, the + %R format string will not return any handler + information when content caching is involved.

+
+ + + +

Examples

+ +

Some commonly used log format strings are:

+ +
+
Common Log Format (CLF)
+
"%h %l %u %t \"%r\" %>s %b"
+ +
Common Log Format with Virtual Host
+
"%v %h %l %u %t \"%r\" %>s %b"
+ +
NCSA extended/combined log format
+
"%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" + \"%{User-agent}i\""
+ +
Referer log format
+
"%{Referer}i -> %U"
+ +
Agent (Browser) log format
+
"%{User-agent}i"
+
+ +

You can use the %{format}t directive multiple + times to build up a time format using the extended format tokens + like msec_frac:

+
+
Timestamp including milliseconds
+
"%{%d/%b/%Y %T}t.%{msec_frac}t %{%z}t"
+ +
+ + +
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+
+

Security Considerations

+

See the security tips + 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.

+
+
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+

BufferedLogs Directive

+ + + + + + + +
Description:Buffer log entries in memory before writing to disk
Syntax:BufferedLogs On|Off
Default:BufferedLogs Off
Context:server config
Status:Base
Module:mod_log_config
+

The BufferedLogs directive causes + mod_log_config 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.

+ +
This directive should be used with caution as a crash might + cause loss of logging data.
+ +
+
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+

CustomLog Directive

+ + + + + + +
Description:Sets filename and format of log file
Syntax:CustomLog file|pipe +format|nickname +[env=[!]environment-variable| +expr=expression]
Context:server config, virtual host
Status:Base
Module:mod_log_config
+

The CustomLog 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.

+ +

The first argument, which specifies the location to which + the logs will be written, can take one of the following two + types of values:

+ +
+
file
+
A filename, relative to the ServerRoot.
+ +
pipe
+
The pipe character "|", followed by the path + to a program to receive the log information on its standard + input. See the notes on piped logs + for more information. + +

Security:

+

If a program is used, then it will be run as the user who + started httpd. This will be root if the server was + started by root; be sure that the program is secure.

+
+

Note

+

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.

+
+
+ +

The second argument specifies what will be written to the + log file. It can specify either a nickname defined by + a previous LogFormat + directive, or it can be an explicit format string as + described in the log formats section.

+ +

For example, the following two sets of directives have + exactly the same effect:

+ + 
# CustomLog with format nickname
+LogFormat "%h %l %u %t \"%r\" %>s %b" common
+CustomLog "logs/access_log" common
+
+# CustomLog with explicit format string
+CustomLog "logs/access_log" "%h %l %u %t \"%r\" %>s %b"
+ + +

The third argument is optional and controls whether or + not to log a particular request. The condition can be the + presence or absence (in the case of a 'env=!name' + clause) of a particular variable in the server + environment. Alternatively, the condition + can be expressed as arbitrary boolean expression. If the condition is not satisfied, the request + will not be logged. References to HTTP headers in the expression + will not cause the header names to be added to the Vary header.

+ +

Environment variables can be set on a per-request + basis using the mod_setenvif + and/or mod_rewrite modules. For + 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:

+ + 
SetEnvIf Request_URI \.gif$ gif-image
+CustomLog "gif-requests.log" common env=gif-image
+CustomLog "nongif-requests.log" common env=!gif-image
+ + +

Or, to reproduce the behavior of the old RefererIgnore + directive, you might use the following:

+ + 
SetEnvIf Referer example\.com localreferer
+CustomLog "referer.log" referer env=!localreferer
+ + +
+
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+

GlobalLog Directive

+ + + + + + + +
Description:Sets filename and format of log file
Syntax:GlobalLogfile|pipe +format|nickname +[env=[!]environment-variable| +expr=expression]
Context:server config
Status:Base
Module:mod_log_config
Compatibility:Available in Apache HTTP Server 2.4.19 and later
+ +

The GlobalLog directive defines a log shared + by the main server configuration and all defined virtual hosts.

+ +

The GlobalLog directive is identical to + the CustomLog directive, apart from the following + differences:

+
    +
  • GlobalLog is not valid in virtual host + context.
    • +
  • GlobalLog is used by virtual hosts that + define their own CustomLog, unlike a + globally specified CustomLog.
    • +
+ +
+
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+

LogFormat Directive

+ + + + + + + +
Description:Describes a format for use in a log file
Syntax:LogFormat format|nickname +[nickname]
Default:LogFormat "%h %l %u %t \"%r\" %>s %b"
Context:server config, virtual host
Status:Base
Module:mod_log_config
+

This directive specifies the format of the access log + file.

+ +

The LogFormat 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 TransferLog + directives. The single argument can specify an explicit + format as discussed in the custom log + formats section above. Alternatively, it can use a + nickname to refer to a log format defined in a + previous LogFormat directive as described + below.

+ +

The second form of the LogFormat + directive associates an explicit format with a + nickname. This nickname can then be used in + subsequent LogFormat or + CustomLog directives + rather than repeating the entire format string. A + LogFormat directive that defines a nickname + does nothing else -- that is, it only + defines the nickname, it doesn't actually apply the format and make + it the default. Therefore, it will not affect subsequent + TransferLog directives. + In addition, LogFormat cannot use one nickname + to define another nickname. Note that the nickname should not contain + percent signs (%).

+ +

Example

LogFormat "%v %h %l %u %t \"%r\" %>s %b" vhost_common
+
+ + +
+
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+

TransferLog Directive

+ + + + + + +
Description:Specify location of a log file
Syntax:TransferLog file|pipe
Context:server config, virtual host
Status:Base
Module:mod_log_config
+

This directive has exactly the same arguments and effect as + the CustomLog + 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 + LogFormat directive + which does not define a nickname. Common Log Format is used if no + other format has been specified.

+ +

Example

LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-agent}i\""
+TransferLog logs/access_log
+
+ +
+
+
+

Available Languages:  en  | + fr  | + ja  | + ko  | + tr 

+
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Comments

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