man > rotatelogs(8)

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|filesize(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 strf‐
              time(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 executing after a rotation, the old log file is passed as the second argu‐
              ment. rotatelogs does not wait for the specified program to terminate before  continu‐
              ing  to  operate, and will not log any error code returned on termination. The spawned
              program uses the same stdin, stdout, and stderr as rotatelogs itself, and also  inher‐
              its the environment.

       -f     Causes  the logfile to be opened immediately, as soon as rotatelogs starts, instead of
              waiting for the first logfile entry to be read (for non-busy sites,  there  may  be  a
              substantial  delay  between  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 '%' charac‐
              ters 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 actions.

       -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 truncation of the  target  file.  For  size
              based  rotation  without -t and existing log files in place, this option may result in
              unintuitive behavior such as initial log entries being sent to  "logfile.1",  and  en‐
              tries  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 occurs at  the  beginning
              of  this interval. For example, if the rotation time is 3600, the log file will be ro‐
              tated 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.)

       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 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 "|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 multiple of the rotation time, so you  can  syn‐
       chronize  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, lo‐
       cal 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 scenario 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 second of the month, /var/log/log‐
       file.02 is truncated and new entries will be added to the top. This  example  keeps  approxi‐
       mately 1 months worth of logs without external maintenance.


PORTABILITY
       The  following logfile format string substitutions should be supported by all strftime(3) im‐
       plementations, 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)