NEWSYSLOG(8) BSD System Manager's Manual NEWSYSLOG(8)
newsyslog, newsyslog.conf - rotate log files
newsyslog [-Fmnrv] [-a directory] [-f config_file] [log ...]
The newsyslog utility rotates log files when they exceed a configurable
size or age. The log file is renamed to log.0 and an empty file is creat-
ed in its place. An archive of older logs may be kept: in order of in-
creasing age, these files are named log.1, log.2, and so on. When their
number exceeds a given limit, the oldest is removed. The archived logs
may also be compressed.
The options are as follows:
-a directory
Specify a directory into which archived log files will be writ-
ten. If directory is a relative path, it is appended to the
parent directory of each log and the archived log is stored in
the result. If an absolute path is given, all archived logs are
stored in the given directory. If directory does not exist for a
specified log, it is ignored for that entry and the log is rotat-
ed as if the -a option was not specified.
-F Force newsyslog to trim logs regardless of the size and/or age
requirements specified in /etc/newsyslog.conf. This option may be
combined with the -n or -v flags to aid in debugging problems
with /etc/newsyslog.conf.
-f config_file
Use config_file instead of /etc/newsyslog.conf for the configura-
tion file.
-m Monitoring mode; only entries marked with an 'M' in flags are
processed. For each log file being monitored, any log output
since the last time newsyslog was run with the -m flag is mailed
to the user listed in the monitor notification section.
-n Do not trim the logs, but instead print out what would be done if
this option were not specified.
-r Removes the restriction that newsyslog must be running as root.
Note that in this mode newsyslog will not be able to send a
SIGHUP signal to syslogd(8).
-v Place newsyslog in verbose mode. In this mode it will print out
each log and its reasons for either trimming that log or skipping
it.
In the default system configuration, newsyslog is run by cron(8), but it
may also be run manually. If one or more log files are specified on the
command line, only the specified files are rotated. Note that each log
specified must have an entry in /etc/newsyslog.conf.
A log can be archived because of two reasons: The log file can have grown
bigger than a preset size in kilobytes, or a preset number of hours may
have elapsed since the last log archive. The granularity of newsyslog is
dependent on how often it is scheduled to run in cron(8). Since the pro-
gram is quite fast, it may be scheduled to run every hour without any ill
effects.
When starting up, newsyslog reads in a configuration file to determine
which logs should be looked at. By default, this configuration file is
/etc/newsyslog.conf. Each line of the file contains information about a
particular log file that should be handled by newsyslog. Each line has
five mandatory fields and up to three optional fields, with whitespace
separating each field. Blank lines or lines beginning with a hash mark
('#') are ignored. The fields of the configuration file are as follows:
logfile_name
The full pathname of the system log file to be archived.
owner:group
This optional field specifies the owner and group for the archive
file. The ':' is essential, even if the owner or group field is
left blank. The fields may be numeric, or a name which is looked
up in the system password and group databases. For backwards com-
patibility, a '.' may be used instead of a ':'. If either owner or
group is not specified, the owner and/or group of the existing log
file is used.
mode File mode (in octal) to use for created log files and archives.
count The number of archives to be kept besides the log file itself.
size When the size of the log file (in kilobytes) reaches this point,
the log file is trimmed as described above. If this field is re-
placed by an asterisk '*', or set to '0', then the size of the log
file is not taken into account when determining when to trim the
log file. By default, files smaller than 256 bytes are not rotated
unless the 'A' (always rotate) or 'B' (binary) flag is set or the
-F option is specified. This prevents newsyslog from rotating
files consisting solely of a message indicating that the log file
has been turned over.
when The when field can consist of an interval, a specific time, or
both. If the when field consists of an asterisk ('*'), log rota-
tion will depend only on the contents of the size field. Other-
wise, the when field consists of an optional interval in hours,
possibly followed by an '@'-sign and a time in a restricted ISO
8601 format or by a '$'-sign and a time specification for logfile
rotation at a fixed time once per day, per week or per month.
If a time is specified, the log file will only be trimmed if
newsyslog is run within one hour of the specified time. If an in-
terval is specified, the log file will be trimmed if that many
hours have passed since the last rotation. When both a time and an
interval are specified, both conditions must be satisfied for the
rotation to take place.
There is no provision for the specification of a time zone. There
is little point in specifying an explicit minutes or seconds com-
ponent in the current implementation, since the only comparison is
'within the hour'.
ISO 8601 restricted time format: The lead-in character for a res-
tricted ISO 8601 time is an '@'-sign. The particular format of the
time in restricted ISO 8601 is: [[[[[cc]yy]mm]dd][T[HH[MM[SS]]]]].
Optional date fields default to the appropriate component of the
current date; optional time fields default to midnight. For exam-
ple, if today is January 22, 1999, the following date specifica-
tions are all equivalent:
'19990122T000000'
'990122T000000'
'0122T000000'
'22T000000'
'T000000'
'T0000'
'T00'
'22T'
'T'
''
Day, week and month time format: The lead-in character for day,
week and month specification is a dollar sign ($). The particular
format of day, week and month specification is: [DHH], Ww[DHH]],
and Mdd[DHH]], respectively. Optional time fields default to mid-
night. The ranges for day and hour specifications are:
HH hours, range 0 ... 23
w day of week, range 0 ... 6, 0 = Sunday
dd day of month, range 1 ... 31, or the letter L or l
to specify the last day of the month.
Some examples:
$D0 rotate every night at midnight (same as @T00)
$D23 rotate every day at 23:00 hr (same as @T23)
$W0D23 rotate every week on Sunday at 23:00 hr
$W5D16 rotate every week on Friday at 16:00 hr
$M1D0 rotate on the first day of every month at midnight
(i.e., the start of the day; same as @01T00)
$M5D6 rotate on every 5th day of the month at 6:00 hr
(same as @05T06)
flags The optional flags field (which must begin, case-insensitively,
with a valid flag letter, or it is skipped) specifies whether any
special processing should be done. The flags are as follows:
'A' Archive even tiny files, e.g. for EU-DSGVO compliance.
'B' Binary file: skip writing the usual ASCII message to indi-
cate the fact that the logs have been turned over to the
end of the archived and the beginning of the new file.
'F' Follow symbolic links.
'M' Marks the entry as a monitored log file (see below).
'Z' Compress the archive files to save space, using gzip(1).
monitor
Specify the username (or email address) that should receive notif-
ication messages if this is a monitored log file. Notification
messages are sent as email; the operator deserves what they get if
they mark the mail log file as monitored. This field is only valid
when the 'M' flag is set and may not start with a slash, double
quote, or the string 'SIG', which indicate the fields below.
pid_file
This optional field specifies the absolute path of a file contain-
ing the PID of a process to send a signal (usually SIGHUP) to in-
stead of /var/run/syslog.pid.
signal
Specify the signal to send to the process instead of SIGHUP.
Signal names must start with "SIG" and be the signal name
(e.g. SIGUSR1), not the signal number.
command
This optional field specifies a command to run instead of sending
a signal to the process. The command must be enclosed in double
quotes ('"'). The empty string, '""', can be used to prevent
newsyslog from sending a signal or running a command. You cannot
specify both a command and a PID file. NOTE: If you specify a com-
mand to be run, newsyslog will not send a SIGHUP to syslogd(8).
/etc/newsyslog.conf default configuration file
The newsyslog utility exits 0 on success, and >0 if an error occurs.
compress(1), gzip(1), syslog(3), syslogd(8)
Theodore Ts'o, MIT Project Athena
Copyright 1987, Massachusetts Institute of Technology
MirBSD #10-current May 2, 2018 3