（转）rotatelogs - Piped logging program to rotate Apache logs

原文：http://publib.boulder.ibm.com/httpserv/manual60/programs/rotatelogs.html

rotatelogs is a simple program for use in conjunction with Apache's piped logfile feature. It supports rotation based on a time interval or maximum size of the log.

• Synopsis
• Options
• Examples
• Portability

Synopsis

rotatelogs [ -l ] [ -W ] logfile rotationtime|filesizeM [ offset ]

Options

-l

Causes the use of local time rather than GMT as the base for the interval or for strftime(3) formatting with size-based rotation. Note that using -l in an environment which changes the GMT offset (such as for BST or DST) can lead to unpredictable results! -l is supported with IBM HTTP Server 2.0 with cumulative fix PQ90698 or later. -l is ignored when rotating based on file size on levels of IBM HTTP Server without APAR PK56939.

-W

Activates additional processing that monitors the web server parent process and exits the rotatelogs process if the parent is no longer running. This option alleviates situations where the rotatelogs processes become orphaned during shutdown or restart processing and never exit. It may take up to 30 seconds or more before orphaned rotatelogs processes are exited. It is recommended that this option be used only if you are experiencing orphaned rotatelogs processes.

-W support is added for APAR PK66924. This option is ignored when the operating system is not a Windows operating system.

logfile

The path plus basename of the logfile. If logfile includes any '%' characters, it is treated as a format string for strftime(3). Otherwise, the suffix.nnnnnnnnnn is automatically added and is the time in seconds. Both formats compute the start time from the beginning of the current period. For example, if a rotation time of 86400 is specified, the hour, minute, and second fields created by strftime(3) format will all be zero, referring to the beginning of the current 24-hour period (midnight).

The directory path, excluding the basename of the logfile, must already exist.

If you use a piped logger for the ErrorLog defined in the base server configuration , and your piped logger is unable to write to the logfile it's configured for, no error reporting from the server or the piped logging program will be available.

rotationtime

The time between log file rotations in seconds. The rotation occurs at the beginning of this interval. For example, if the rotation time is 3600, the log file will be rotated at the beginning of every hour; if the rotation time is 86400, the log file will be rotated every night at midnight. (If no data is logged during an interval, no file will be created.)

filesizeM

The maximum file size in megabytes followed by the letter M to specify size rather than time.

offset

The number of minutes offset from UTC. If omitted, zero is assumed and UTC is used. For example, to use local time in the zone UTC -5 hours, specify a value of -300 for this argument. In most cases, -l should be used instead of specifying an offset.

Examples

CustomLog "|/path/to/IHS/bin/rotatelogs /var/logs/logfile 86400" common

This creates the files /var/logs/logfile.nnnn where nnnn is the system time at which the log nominally starts (this time will always be a multiple of the rotation time, so you can synchronize cron scripts with it). At the end of each rotation time (here after 24 hours) a new log is started.

CustomLog "|/path/to/IHS/bin/rotatelogs -l /var/logs/logfile.%Y.%m.%d 86400" common

This creates the files /var/logs/logfile.yyyy.mm.dd where yyyy is the year, mm is the month, and dd is the day of the month. Logging will switch to a new file every day at midnight, local time.

CustomLog "|/path/to/IHS/bin/rotatelogs /var/logs/logfile 5M" common

This configuration will rotate the logfile whenever it reaches a size of 5 megabytes.

ErrorLog "|/path/to/IHS/bin/rotatelogs /var/logs/errorlog.%Y-%m-%d-%H_%M_%S 5M"

This configuration will rotate the error logfile whenever it reaches a size of 5 megabytes, and the suffix to the logfile name will be created of the formerrorlog.YYYY-mm-dd-HH_MM_SS.

Portability

The following logfile format string substitutions should be supported by all strftime(3) implementations, see the strftime(3) man page for library-specific extensions.

%A	full weekday name (localized)
%a	3-character weekday name (localized)
%B	full month name (localized)
%b	3-character month name (localized)
%c	date and time (localized)
%d	2-digit day of month
%H	2-digit hour (24 hour clock)
%I	2-digit hour (12 hour clock)
%j	3-digit day of year
%M	2-digit minute
%m	2-digit month
%p	am/pm of 12 hour clock (localized)
%S	2-digit second
%U	2-digit week of year (Sunday first day of week)
%W	2-digit week of year (Monday first day of week)
%w	1-digit weekday (Sunday first day of week)
%X	time (localized)
%x	date (localized)
%Y	4-digit year
%y	2-digit year
%Z	time zone name
%%	literal `%'