ROTATELOGS(8) rotatelogs ROTATELOGS(8)
NAME
rotatelogs - Piped logging program to rotate Apache logs
SYNOPSIS
rotatelogs [ -l ] [ -L linkname ] [ -p program ] [ -f ] [ -D ] [ -t ] [
-v ] [ -e ] [ -c ] [ -n number-of-files ] logfile rotationtime|file-
size(B|K|M|G) [ offset ]
SUMMARY
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.
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.
-L linkname
-p program
If given, rotatelogs will execute the specified program every
time a new log file is opened. The filename of the newly opened
file is passed as the first argument to the program. If execut-
ing after a rotation, the old log file is passed as the second
argument. rotatelogs does not wait for the specified program to
terminate before continuing to operate, and will not log any er-
ror code returned on termination. The spawned program uses the
same stdin, stdout, and stderr as rotatelogs itself, and also
inherits the environment.
-f Causes the logfile to be opened immediately, as soon as rotatel-
ogs starts, instead of waiting for the first logfile entry to be
read (for non-busy sites, there may be a substantial delay be-
tween when the server is started and when the first request is
handled, meaning that the associated logfile does not "exist"
until then, which causes problems from some automated logging
tools)
-D Creates the parent directories of the path that the log file
will be placed in if they do not already exist. This allows
strftime(3) formatting to be used in the path and not just the
filename.
-t Causes the logfile to be truncated instead of rotated. This is
useful when a log is processed in real time by a command like
tail, and there is no need for archived data. No suffix will be
added to the filename, however format strings containing '%'
characters will be respected.
-T Causes all but the initial logfile to be truncated when opened.
This is useful when the format string contains something that
will loop around, such as the day of the month. Available in
2.4.56 and later.
-v Produce verbose output on STDERR. The output contains the result
of the configuration parsing, and all file open and close ac-
tions.
-e Echo logs through to stdout. Useful when logs need to be further
processed in real time by a further tool in the chain.
-c Create log file for each interval, even if empty.
-n number-of-files
Use a circular list of filenames without timestamps. This option
overwrites log files at startup and during rotation. With -n 3,
the series of log files opened would be "logfile", "logfile.1",
"logfile.2", then overwriting "logfile". When this program first
opens "logfile", the file will only be truncated if -t is also
provided. Every subsequent rotation will always begin with trun-
cation of the target file. For size based rotation without -t
and existing log files in place, this option may result in unin-
tuitive behavior such as initial log entries being sent to "log-
file.1", and entries in "logfile.1" not being preserved even if
later "logfile.n" have not yet been used. Available in 2.4.5 and
later.
logfile
rotationtime
The time between log file rotations in seconds. The rotation oc-
curs at the beginning of this interval. For example, if the ro-
tation time is 3600, the log file will be rotated at the begin-
ning 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.)
filesize(B|K|M|G)
The maximum file size in followed by exactly one of the letters
B (Bytes), K (KBytes), M (MBytes) or G (GBytes). .PP When time
and size are specified, the size must be given after the time.
Rotation will occur whenever either time or size limits are
reached.
offset The number of minutes offset from UTC. If omitted, zero is as-
sumed 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 "|bin/rotatelogs /var/log/logfile 86400" common
This creates the files /var/log/logfile.nnnn where nnnn is the system
time at which the log nominally starts (this time will always be a mul-
tiple 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 "|bin/rotatelogs -l /var/log/logfile.%Y.%m.%d 86400" common
This creates the files /var/log/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 "|bin/rotatelogs /var/log/logfile 5M" common
This configuration will rotate the logfile whenever it reaches a size
of 5 megabytes.
ErrorLog "|bin/rotatelogs /var/log/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 form errorlog.YYYY-mm-dd-HH_MM_SS.
CustomLog "|bin/rotatelogs -t /var/log/logfile 86400" common
This creates the file /var/log/logfile, truncating the file at startup
and then truncating the file once per day. It is expected in this sce-
nario that a separate process (such as tail) would process the file in
real time.
CustomLog "|bin/rotatelogs -T /var/log/logfile.%d 86400" common
If the server is started (or restarted) on the first of the month, this
appends to /var/log/logfile.01. When a log entry is written on the sec-
ond of the month, /var/log/logfile.02 is truncated and new entries will
be added to the top. This example keeps approximately 1 months worth of
logs without external maintenance.
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 `%'
Apache HTTP Server 2023-03-05 ROTATELOGS(8)
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