xref: /netbsd-src/usr.bin/newsyslog/newsyslog.8 (revision d5a7953cd7f1b19e3150ac707edef99c4827da31)
1.\"	$NetBSD: newsyslog.8,v 1.46 2021/03/02 10:17:25 uwe Exp $
2.\"
3.\" Copyright (c) 1999, 2000 Andrew Doran <ad@NetBSD.org>
4.\" All rights reserved.
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7.\" modification, are permitted provided that the following conditions
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25.\" This file contains changes from the Open Software Foundation.
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27.\" Copyright 1988, 1989 by the Massachusetts Institute of Technology
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30.\" and its documentation for any purpose and without fee is
31.\" hereby granted, provided that the above copyright notice
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41.\" from FreeBSD: newsyslog.8,v 1.14.2.1 1999/02/25 18:38:33 wollman Exp
42.\"
43.Dd March 1, 2021
44.Dt NEWSYSLOG 8
45.Os
46.Sh NAME
47.Nm newsyslog ,
48.Nm newsyslog.conf
49.Nd maintain system log files to manageable sizes
50.Sh SYNOPSIS
51.Nm newsyslog
52.Op Fl Fnrsv
53.Op Fl f Ar config_file
54.Op Pa file ...
55.Sh DESCRIPTION
56.Nm
57is a program that should be scheduled to run periodically by
58.Xr cron 8 .
59When it is executed it archives log files if necessary.
60If a log file is determined to require archiving,
61.Nm
62rearranges the files so that
63.Dq Va logfile
64is empty,
65.Dq Va logfile Ns Li \&.0
66has
67the last period's logs in it,
68.Dq Va logfile Ns Li \&.1
69has the next to last
70period's logs in it and so on, up to a user-specified number of
71archived logs.
72Optionally the archived logs can be compressed to save
73space.
74.Pp
75A log can be archived for three reasons:
76.Bl -enum -offset indent
77.It
78It is larger than the configured size (in kilobytes).
79.It
80A configured number of hours have elapsed since the log was last
81archived.
82.It
83The configured time for rotation of the log occurred within the last 60
84minutes.
85.El
86.Pp
87The granularity of
88.Nm
89is dependent on how often it is scheduled to run by
90.Xr cron 8 .
91It is recommended that
92.Nm
93be run once hourly.
94.Pp
95When starting up,
96.Nm
97reads in a configuration file to determine which logs may potentially
98be archived.
99By default, this configuration file is
100.Pa /etc/newsyslog.conf .
101Each line of the file contains information about a particular log file
102that should be handled by
103.Nm .
104Each line has six mandatory fields and three optional fields, with
105whitespace separating each field.
106Blank lines or lines beginning with
107.Ql #
108are ignored.
109The fields of the configuration file are as
110follows:
111.Bl -tag -width Fl
112.It Ar logfile_name
113Name of the system log file to be archived.
114.It Ar owner Ns Li \&: Ns Ar group
115This optional field specifies the owner and group for the archive file.
116The
117.Ql \&:
118is essential, even if the
119.Ar owner
120or
121.Ar group
122field is left blank.
123The field may be numeric, or a name which is present in
124.Pa /etc/passwd
125or
126.Pa /etc/group .
127For backward compatibility,
128.Ql \&.
129is usable in lieu of
130.Ql \&: ,
131however use of this feature is discouraged.
132.It Ar mode
133Specify the mode of the log file and archives.
134.It Ar ngen
135Specify the number of archive files to be kept
136besides the log file itself.
137.It Ar size
138When the size of the log file reaches
139.Ar size
140kilobytes, the log file will be trimmed as described above.
141If this field is replaced by an asterisk
142.Pq Ql \&* ,
143then the size of the log file is not taken into account
144when determining when to trim the log file.
145.It Ar when
146The
147.Ar when
148field can consist of an interval, a specific time, or both.
149If the
150.Ar when
151field is an asterisk
152.Pq Ql \&*
153log rotation will depend only on the contents of the
154.Ar size
155field.
156Otherwise, the
157.Ar when
158field consists of an optional interval in hours, optionally followed
159by an
160.So Li \&@ Sc Ns No -sign
161and a time in a restricted ISO 8601 format or by an
162.So Li \&$ Sc Ns No -sign
163and a time specification for logfile rotation at a fixed time once
164per day, per week or per month.
165.Pp
166If a time is specified, the log file will only be trimmed if
167.Nm
168is run within one hour of the specified time.
169If an
170interval is specified, the log file will be trimmed if that many hours have
171passed since the last rotation.
172When both a time and an interval are
173specified, the log will be trimmed if either condition is met.
174.Pp
175There is no provision for specification of a timezone.
176There is
177little point in specifying an explicit minutes or seconds component in
178the current implementation, since the only comparison is `within the
179hour'.
180.Pp
181.Em ISO 8601 restricted time format
182.Pp
183The lead-in character for a restricted ISO 8601 time is an
184.So Li \&@ Sc Ns No -sign .
185The particular format of the time in restricted ISO 8601 is:
186.Sm off
187.Oo
188.Oo
189.Oo
190.Oo
191.Oo
192.Va \&cc
193.Oc
194.Va \&yy
195.Oc
196.Va \&mm
197.Oc
198.Va \&dd
199.Oc
200.Oo
201.Li \&T
202.Oo
203.Va \&hh
204.Oo
205.Va \&mm
206.Oo
207.Va \&ss
208.Oc
209.Oc
210.Oc
211.Oc
212.Oc .
213.Sm on
214Optional date fields default to the appropriate component of the
215current date; optional time fields default to midnight; hence if today
216is January 22, 1999, the following date specifications are all
217equivalent:
218.Pp
219.Bl -item -compact -offset indent
220.It
221.Sq Li 19990122T000000
222.It
223.Sq Li 990122T000000
224.It
225.Sq Li 0122T000000
226.It
227.Sq Li 22T000000
228.It
229.Sq Li T000000
230.It
231.Sq Li T0000
232.It
233.Sq Li T00
234.It
235.Sq Li 22T
236.It
237.Sq Li \&T
238.It
239.Sq Li \&
240.El
241.Pp
242.Em Day, week and month time format
243.Pp
244The lead-in character for day, week and month specification is a
245.So Li \&$ Sc Ns No -sign .
246The particular format of day, week and month specification is:
247.Oo
248.Li D Ns Va \&hh
249.Oc ,
250.Sm off
251.Oo
252.Li W Ns Va \&w
253.Oo
254.Li D Ns Va \&hh
255.Oc
256.Oc
257.Sm on
258and
259.Sm off
260.Oo
261.Li M Ns Va \&dd
262.Oo
263.Li D Ns Va \&hh
264.Oc
265.Oc
266.Sm on
267respectively.
268Optional time fields default to midnight.
269The ranges for day and hour specifications are:
270.Pp
271.Bl -tag -width Ds -compact -offset indent
272.It Ar hh
273hours, range 0 ... 23
274.It Ar w
275day of week, range 0 ... 6, 0 = Sunday
276.It Ar dd
277day of month, range 1 ... 31, or the letter
278.Ql L
279or
280.Ql l
281to specify the last day of the month.
282.El
283.Pp
284Some examples:
285.Pp
286.Bl -tag -width Ds -compact -offset indent
287.It Li $D0
288rotate every night at midnight
289.It Li $D23
290rotate every day at 23:00 hr
291.It Li $W0D23
292rotate every week on Sunday at 23:00 hr
293.It Li $W5D16
294rotate every week on Friday at 16:00 hr
295.It Li $MLD0
296rotate at the last day of every month at midnight
297.It Li $M5D6
298rotate on every 5th day of month at 6:00 hr
299.El
300.It Ar flags
301This field specifies any special processing that is required.
302These flags are parsed in a case insensitive manner.
303Individual
304flags and their meanings:
305.Bl -tag -width indent
306.It Ic \-
307This flag means nothing \(em it is used as a spacer when no flags are set.
308.It Ic b
309The file is a binary file or is not in
310.Xr syslogd 8
311format: the ASCII message which
312.Nm
313inserts to indicate that the logs have been trimmed should not be included.
314.It Ic c
315Create an empty log file if none currently exists.
316.It Ic e
317Do not rotate log file with zero size (empty).
318This flag is mostly usable in conjunction with
319.Ic b
320flag that prevents
321.Nm
322from inserting an ASCII informational message.
323.It Ic j
324Archived log files should be compressed with
325.Xr bzip2 1
326to save space.
327.It Ic n
328No signal should be sent when the log is trimmed.
329.It Ic p
330The first historical log file (i.e. the historical log file with the suffix
331.Ql \.0 )
332should not be compressed.
333.It Ic x
334Archived log files should be compressed with
335.Xr xz 1
336to save space.
337.It Ic z
338Archived log files should be compressed with
339.Xr gzip 1
340to save space.
341.El
342.It Ar path_to_pid_file
343This optional field specifies
344the file name to read to find the daemon process id.
345If this field is missing, it defaults to the
346.Pa /var/run/syslogd.pid
347file.
348A signal of type
349.Ar sigtype
350is sent to the process id contained in this
351.Ar path_to_pid_file
352file.
353This field must start with
354.Ql /
355in order to be recognized properly.
356.It Ar sigtype
357This optional field specifies the type of signal to be sent to the daemon
358process.
359This may be a numeric or symbolic value.
360By default a
361.Dv SIGHUP
362(hang-up) will be sent.
363.El
364.Sh OPTIONS
365The following options can be used with newsyslog:
366.Bl -tag -width indent
367.It Fl F
368Force trimming of the logs, even if the trim conditions have not been met.
369This option is useful for diagnosing system problems by providing you with
370fresh logs.
371.It Fl f Ar config_file
372Use
373.Ar config_file
374instead of
375.Pa /etc/newsyslog.conf
376as the configuration file.
377.It Fl n
378Do not trim the logs, but print out what would be done if this option were not
379specified:
380.Fl n
381implies
382.Fl v .
383.It Fl r
384Remove the restriction that
385.Nm
386must be running as root.
387When running as a regular user,
388.Nm
389will not be able to send a
390.Dv SIGHUP
391signal to
392.Xr syslogd 8 ,
393so this option should be used only when debugging or trimming user generated
394logs.
395.It Fl s
396Do not signal daemon processes.
397.It Fl v
398Run in verbose mode.
399In this mode each action that is taken will be printed.
400.El
401.Pp
402If additional command line arguments are given,
403.Nm
404will only examine log files that match those arguments; otherwise, it
405will examine all files listed in the configuration file.
406.Sh FILES
407.Bl -tag -width /etc/newsyslog.confxxxx -compact
408.It Pa /etc/newsyslog.conf
409.Nm
410configuration file.
411.El
412.Sh SEE ALSO
413.Xr bzip2 1 ,
414.Xr gzip 1 ,
415.Xr syslog 3 ,
416.Xr syslogd 8
417