From: Andre Malo 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.
@@ -18,21 +17,18 @@
of the request. Three directives are provided by this module:
- Base Module Identifier:
log_config_module Source File:
mod_log_config.c Summary
-
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.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.
The format argument to the LogFormat
and
- CustomLog
directives is a string. This string is
+
The format argument to the LogFormat
and CustomLog
directives is a string. This string is
logged to the log file for each request. It can contain literal
characters copied into the log files and the c-type control
characters "\n" and "\t" to represent new-lines and tabs.
@@ -40,197 +36,170 @@
back-slashes.
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:
- -%...a: | -Remote IP-address | ||||||
%...A: | -Local IP-address | ||||||
%...B: | -Bytes sent, excluding HTTP headers. | ||||||
%...b: | -Bytes sent, excluding HTTP headers. In CLF format -i.e. a '-' rather than a 0 when no bytes are sent. | ||||||
%...{Foobar}C: | -The contents of cookie "Foobar" in the request sent to the server. | ||||||
%...D: | -The time taken to serve the request, in microseconds. | ||||||
%...{FOOBAR}e: | -The contents of the environment variable FOOBAR | ||||||
%...f: | -Filename | ||||||
%...h: | -Remote host | ||||||
%...H | -The request protocol | ||||||
%...{Foobar}i: | -The contents of Foobar: header line(s) in the request -sent to the server. | ||||||
%...l: | -Remote logname (from identd, if supplied) | ||||||
%...m: | -The request method | ||||||
%...{Foobar}n: | -The contents of note "Foobar" from another module. | ||||||
%...{Foobar}o: | -The contents of Foobar: header line(s) in the reply. | ||||||
%...p: | -The canonical Port of the server serving the request | ||||||
%...P: | -The process ID of the child that serviced the request. | ||||||
%...q: | -The query string (prepended with a ? if a query string exists, -otherwise an empty string) | ||||||
%...r: | -First line of request | ||||||
%...s: | -Status. For requests that got internally redirected, this is -the status of the *original* request --- %...>s for the last. | ||||||
%...t: | -Time, in common log format time format (standard english format) | ||||||
%...{format}t: | -The time, in the form given by format, which should -be in strftime(3) format. (potentially localized) | ||||||
%...T: | -The time taken to serve the request, in seconds. | ||||||
%...u: | -Remote user (from auth; may be bogus if return status (%s) is 401) | ||||||
%...U: | -The URL path requested, not including any query string. | ||||||
%...v: | -The canonical ServerName of the server serving the request. | ||||||
%...V: | -The server name according to the UseCanonicalName setting. | ||||||
%...X: | -Connection status when response is completed.
-
(This directive was %...c in late versions of Apache 1.3, but
-this conflicted with the historical ssl %...{var}c syntax.)
- | ||||||
%...I: | -Bytes received, including request and headers, cannot be zero. You need to
-enable mod_logio to use this. | ||||||
%...O: | -Bytes sent, including headers, cannot be zero. You need to enable
-mod_logio to use this. |
Format String | +Description | ||||||
---|---|---|---|---|---|---|---|
%...a |
+ Remote IP-address | ||||||
%...A |
+ Local IP-address | ||||||
%...B |
+ Bytes sent, excluding HTTP headers. | ||||||
%...b |
+ Bytes sent, excluding HTTP headers. In CLF format, i.e.
+ a '- ' rather than a 0 when no bytes are sent. | ||||||
%...{Foobar}C |
+ The contents of cookie Foobar in the request sent + to the server. | ||||||
%...D |
+ The time taken to serve the request, in microseconds. | ||||||
%...{FOOBAR}e |
+ The contents of the environment variable + FOOBAR | ||||||
%...f |
+ Filename | ||||||
%...h |
+ Remote host | ||||||
%...H |
+ The request protocol | ||||||
%...{Foobar}i |
+ The contents of Foobar: header line(s)
+ in the request sent to the server. | ||||||
%...l |
+ Remote logname (from identd, if supplied) | ||||||
%...m |
+ The request method | ||||||
%...{Foobar}n |
+ The contents of note Foobar from another + module. | ||||||
%...{Foobar}o |
+ The contents of Foobar: header line(s)
+ in the reply. | ||||||
%...p |
+ The canonical port of the server serving the request | ||||||
%...P |
+ The process ID of the child that serviced the request. | ||||||
%...q |
+ The query string (prepended with a ? if a query
+ string exists, otherwise an empty string) | ||||||
%...r |
+ First line of request | ||||||
%...s |
+ Status. For requests that got internally redirected, this is
+ the status of the *original* request --- %...>s
+ for the last. | ||||||
%...t |
+ Time, in common log format time format (standard english + format) | ||||||
%...{format}t |
+ The time, in the form given by format, which should be in
+ strftime(3) format. (potentially localized) | ||||||
%...T |
+ The time taken to serve the request, in seconds. | ||||||
%...u |
+ Remote user (from auth; may be bogus if return status
+ (%s ) is 401) | ||||||
%...U |
+ The URL path requested, not including any query string. | ||||||
%...v |
+ The canonical ServerName
+ of the server serving the request. | ||||||
%...V |
+ The server name according to the UseCanonicalName setting. | ||||||
%...X |
+ Connection status when response is completed:
+
+
(This directive was | ||||||
%...I |
+ Bytes received, including request and headers, cannot be zero.
+ You need to enable mod_logio to use this. | ||||||
%...O |
+ Bytes sent, including headers, cannot be zero. You need to
+ enable mod_logio to use this. |
The "..." can be nothing at all (e.g., "%h %u
- %r %s %b"
), or it can indicate conditions for inclusion
- of the item (which will cause it to be replaced with "-" if the
- condition is not met). The forms of condition are a list of
+
The "..." can be nothing at all (e.g.,
+ "%h %u %r %s %b"
), or it can indicate conditions for
+ inclusion of the item (which will cause it to be replaced with "-" if
+ the condition is not met). The forms of condition are a list of
HTTP status codes, which may or may not be preceded by "!".
- Thus, "%400,501{User-agent}i" logs User-agent: on 400 errors
- and 501 errors (Bad Request, Not Implemented) only;
- "%!200,304,302{Referer}i" logs Referer: on all requests which
- did not return some sort of normal status.
User-agent:
on 400
+ errors and 501 errors (Bad Request, Not Implemented) only;
+ "%!200,304,302{Referer}i" logs Referer:
on all requests
+ which did not return some sort of normal status.
Note that there is no escaping performed on the strings from - %...r, %...i and %...o. This is mainly to comply with the - requirements of the Common Log Format. This implies that - clients can insert control characters into the log, so care - should be taken when dealing with raw log files.
+%...r
, %...i
and %...o
. This
+ is mainly to comply with the requirements of the Common Log Format.
+ This implies that clients can insert control characters into the log,
+ so care should be taken when dealing with raw log files.
Some commonly used log format strings are:
"%h %l %u %t \"%r\" %>s %b"
"%v %h %l %u %t \"%r\" %>s %b"
"%h %l %u %t \"%r\" %>s %b \"%{Referer}i\"
\"%{User-agent}i\""
"%{Referer}i -> %U"
"%{User-agent}i"
Note that the canonical ServerName and Listen of the server serving the +
Note that the canonical ServerName
and Listen
of the server serving the
request are used for %v
and %p
- respectively. This happens regardless of the UseCanonicalName setting
+ respectively. This happens regardless of the UseCanonicalName
setting
because otherwise log analysis programs would have to duplicate
the entire vhost matching algorithm in order to decide what
host really served the request.
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.
- -The CookieLog
directive sets the
filename for logging of cookies. The filename is relative to the
- serverroot
. This directive is
+ ServerRoot
. This directive is
included only for compatibility with mod_cookies
,
and is deprecated.
Description: | Sets filename and format of log file |
---|---|
Syntax: - | CustomLog
- file|pipe format|nickname
- [env=[!]environment-variable] |
Context: + | CustomLog file|pipe
+format|nickname
+[env=[!]environment-variable] |
Context: | server config, virtual host |
Status: | Base |
Module: - | mod_log_config |
Compatibility: - | Nickname only available in Apache 1.3 or later. -Conditional logging available in 1.3.5 or later. |
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
@@ -241,68 +210,67 @@ Conditional logging available in 1.3.5 or later.
types of values:
ServerRoot
.|
", followed by the path
to a program to receive the log information on its standard
- input. Security: if a program is used, then
- it will be run under the user who started httpd. This will be
- root if the server was started by root; be sure that the
- program is secure.If a program is used, then it will be run under the user who + started httpd. This will be root if the server was started by root; + be sure that the program is secure.
+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.
+ log file. It can specify either a nickname defined by + a previousLogFormat
+ 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"
-
+ # 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 allows the decision on
whether or not to log a particular request to be based on the
presence or absence of a particular variable in the server
environment. If the specified environment
variable is set for the request (or is not set, in the case
- of a 'env=!name
' clause), then the
+ of a 'env=!name
' clause), then the
request will be logged.
Environment variables can be set on a per-request +
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
-
+ SetEnvIf Request_URI \.gif$ gif-image
+ CustomLog gif-requests.log common env=gif-image
+ CustomLog nongif-requests.log common env=!gif-image
+
Description: | Describes a format for use in a log file |
---|---|
Syntax: - | LogFormat
- format|nickname [nickname] |
Default: + | LogFormat format|nickname
+[nickname] |
Default: | LogFormat "%h %l %u %t \"%r\" %>s %b" |
Context: | server config, virtual host |
Status: | Base |
Module: - | mod_log_config |
Compatibility: - | Nickname only available in Apache 1.3 or later. - |
This directive specifies the format of the access log file.
@@ -311,53 +279,47 @@ Conditional logging available in 1.3.5 or later. this directive sets the log format which will be used by logs specified in subsequentTransferLog
directives. The single argument can specify an explicit
- format as discussed in custom log
+ format as discussed in custom log
formats section above. Alternatively, it can use a
- nickname to refer to a log format defined in 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
+ 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.
For example:
- -LogFormat "%v %h %l %u %t \"%r\" %>s %b"
- vhost_common
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 (%
).
+
+
+ LogFormat "%v %h %l %u %t \"%r\" %>s %b" vhost_common
+
Description: | Specifly location of a log file |
---|---|
Syntax: - | TransferLog file|pipe |
Context: + | TransferLog file|pipe |
Context: | server config, virtual host |
Status: | Base |
Module: - | mod_log_config |
Compatibility: - |
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
+ 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
-
+ LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-agent}i\""
+ TransferLog logs/access_log
+