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svlogd(8)		    System Manager's Manual		     svlogd(8)

NAME
       svlogd -	runit's	service	logging	daemon

SYNOPSIS
       svlogd [-tttv] [-r c] [-R xyz] [-l len] [-b buflen] logs

DESCRIPTION
       logs consists of	one or more arguments, each specifying a directory.

       svlogd  continuously reads log data from	its standard input, optionally
       filters log messages, and writes	the data to one	or more	 automatically
       rotated logs.

       Recent log files	can automatically be processed by an arbitrary proces-
       sor program when	they are rotated, and svlogd can be told to alert  se-
       lected log messages to standard error, and through udp.

       svlogd  runs  until  it sees end-of-file	on standard input or is	sent a
       TERM signal, see	below.

   LOG DIRECTORY
       A log directory log contains some number	of old log files, and the cur-
       rent  log file current.	Old log	files have a file name starting	with @
       followed	by a precise timestamp (see the	daemontools' tai64n  program),
       indicating when current was rotated and renamed to this file.

       A  log  directory additionally contains the lock	file lock, maybe state
       and newstate, and optionally the	file config.  svlogd creates necessary
       files if	they don't exist.

       If svlogd has trouble opening a log directory, it prints	a warning, and
       ignores this log	directory.  If svlogd is unable	to open	all log	direc-
       tories  given  at  the  command line, it	exits with an error.  This can
       happen on start-up or after receiving a HUP signal.

   LOG FILE ROTATION
       svlogd appends selected log messages to the current log file.  If  cur-
       rent has	size bytes or more (or there is	a new-line within the last len
       of size bytes), or is older than	a specified amount of time, current is
       rotated:

       svlogd  closes  current,	changes	permission of current to 0755, renames
       current to @timestamp.s,	and starts  with  a  new  empty	 current.   If
       svlogd  sees num	or more	old log	files in the log directory, it removes
       the oldest one.	Note that this doesn't	decrease  the  number  of  log
       files  if  there	are already more than num log files, this must be done
       manually, e.g. for keeping 10 log files:

	ls -1 \@* |sort	|sed -ne '10,$p' |xargs	rm

   PROCESSOR
       If svlogd is told to process recent log	files,	it  saves  current  to
       @timestamp.u,  feeds  @timestamp.u  through  ``sh  -c "processor"'' and
       writes the output to @timestamp.t.  If the processor finishes  success-
       fully,  @timestamp.t  is	 renamed  to @timestamp.s, and @timestamp.u is
       deleted;	otherwise @timestamp.t is deleted and the processor is started
       again.	svlogd also saves any output that the processor	writes to file
       descriptor 5, and makes that output available on	file descriptor	4 when
       running processor on the	next log file rotation.

       A  processor  is	 run  in  the background.  If svlogd sees a previously
       started processor still running when trying to start a new one for  the
       same  log, it blocks until the currently	running	processor has finished
       successfully.  Only the HUP signal works	in that	situation.  Note  that
       this may	block any program feeding its log data to svlogd.

   CONFIG
       On  startup,  and  after	receiving a HUP	signal,	svlogd checks for each
       log directory log if the	configuration file log/config exists,  and  if
       so,  reads  the	file line by line and adjusts configuration for	log as
       follows:

       If the line is empty, or	starts with a ``#'', it	is ignored.  A line of
       the form

       ssize  sets  the	maximum	file size of current when svlogd should	rotate
	      the current log file to size bytes.   Default  is	 1000000.   If
	      size  is	zero, svlogd doesn't rotate log	files.	You should set
	      size to at least (2 * len).

       nnum   sets the number of old log files svlogd should maintain to  num.
	      If svlogd	sees more that num old log files in log	after log file
	      rotation,	it deletes the oldest one.  Default is 10.  If num  is
	      zero, svlogd doesn't remove old log files.

       Nmin   sets  the	minimum	number of old log files	svlogd should maintain
	      to min.  min must	be less	than num.  If min is set,  and	svlogd
	      cannot  write  to	current	because	the filesystem is full,	and it
	      sees more	than min old log files,	it deletes the oldest one.

       ttimeout
	      sets the maximum age of the current log file when	svlogd	should
	      rotate  the  current log file to timeout seconds.	 If current is
	      timeout seconds old, and is not empty, svlogd  forces  log  file
	      rotation.

       !processor
	      tells svlogd to feed each	recent log file	through	processor (see
	      above) on	log file rotation.  By default log files are not  pro-
	      cessed.

       ua.b.c.d[:port]
	      tells  svlogd  to	 transmit the first len	characters of selected
	      log messages to the IP address a.b.c.d, port  number  port.   If
	      port  isn't set, the default port	for syslog is used (514).  len
	      can be set through the -l	option,	 see  below.   If  svlogd  has
	      trouble sending udp packets, it writes error messages to the log
	      directory.  Attention: logging through udp  is  unreliable,  and
	      should be	used in	private	networks only.

       Ua.b.c.d[:port]
	      is  the  same  as	 the u line above, but the log messages	are no
	      longer written to	the log	directory, but transmitted through udp
	      only.   Error  messages from svlogd concerning sending udp pack-
	      ages still go to the log directory.

       pprefix
	      tells svlogd to prefix each line to be written to	the log	direc-
	      tory, to standard	error, or through UDP, with prefix.

       If  a  line  starts  with a -, +, e, or E, svlogd matches the first len
       characters of each log message against pattern and acts accordingly:

       -pattern
	      the log message is deselected.

       +pattern
	      the log message is selected.

       epattern
	      the log message is selected to be	printed	to standard error.

       Epattern
	      the log message is deselected to be printed to standard error.

       Initially each line is selected to be written  to  log/current.	 Dese-
       lected log messages are discarded from log.  Initially each line	is de-
       selected	to be written to standard  err.	  Log  messages	 selected  for
       standard	error are written to standard error.

PATTERN	MATCHING
       svlogd matches a	log message against the	string pattern as follows:

       pattern	is  applied  to	the log	message	one character by one, starting
       with the	first.	A character not	a star (``*'') and not a plus  (``+'')
       matches	itself.	  A  plus matches the next character in	pattern	in the
       log message one or more times.	A  star	 before	 the  end  of  pattern
       matches	any  string  in	the log	message	that does not include the next
       character in pattern.  A	star at	the end	of pattern matches any string.

       Timestamps optionally added by svlogd are not considered	 part  of  the
       log message.

       An  svlogd pattern is not a regular expression.	For example consider a
       log message like	this

	2005-12-18_09:13:50.97618 tcpsvd: info:	pid 1977 from 10.4.1.14

       The following pattern doesn't match

	-*pid*

       because the first star matches up to the	first p	in  tcpsvd,  and  then
       the match fails because i is not	s.  To match this log message, you can
       use a pattern like this instead

	-*: *: pid *

OPTIONS
       -t     timestamp.  Prefix each selected line with a  precise  timestamp
	      (see  the	daemontools' tai64n program) when writing to log or to
	      standard error.

       -tt    timestamp.  Prefix each selected line  with  a  human  readable,
	      sortable	UTC  timestamp	of  the	form YYYY-MM-DD_HH:MM:SS.xxxxx
	      when writing to log or to	standard error.

       -ttt   timestamp.  Prefix each selected line  with  a  human  readable,
	      sortable	UTC  timestamp	of  the	form YYYY-MM-DDTHH:MM:SS.xxxxx
	      when writing to log or to	standard error.

       -r c   replace.	c must be a single character.	Replace	 non-printable
	      characters  in log messages with c.  Characters are replaced be-
	      fore pattern matching is applied.

       -R xyz replace charset.	Additionally to	non-printable characters,  re-
	      place all	characters found in xyz	with c (default	``_'').

       -l len line  length.  Pattern matching applies to the first len charac-
	      ters of a	log message only.  Default is 1000.

       -b buflen
	      buffer size.  Set	the size of the	buffer svlogd uses when	 read-
	      ing  from	standard input and writing to logs to buflen.  Default
	      is 1024.	buflen must be greater than len.  For svlogd instances
	      that process a lot of data in short time,	the buffer size	should
	      be increased to improve performance.

       -v     verbose.	Print verbose messages to standard error.

SIGNALS
       If svlogd is sent a HUP signal, it closes and reopens all logs, and up-
       dates their configuration according to log/config.  If svlogd has trou-
       ble opening a log directory, it prints a	warning, and discards this log
       directory.   If	svlogd	is unable to open all log directories given at
       the command line, it exits with an error.

       If svlogd is sent a TERM	signal,	or if it sees end-of-file on  standard
       input,  it stops	reading	standard input,	processes the data in the buf-
       fer, waits for all processor subprocesses to finish if any, and exits 0
       as soon as possible.

       If  svlogd  is sent an ALRM signal, it forces log file rotation for all
       logs with a non empty current log file.

SEE ALSO
       sv(8),  runsv(8),  chpst(8),  runit(8),	 runit-init(8),	  runsvdir(8),
       runsvchdir(8)

       http://smarden.org/runit/

AUTHOR
       Gerrit Pape <pape@smarden.org>

								     svlogd(8)

NAME | SYNOPSIS | DESCRIPTION | PATTERN MATCHING | OPTIONS | SIGNALS | SEE ALSO | AUTHOR

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