NAME
newsyslog —
maintain system log files
to manageable sizes
SYNOPSIS
newsyslog |
[-nrsvF]
[-f
config_file]
[file ...] |
DESCRIPTION
newsyslog is a program that should be scheduled to run
periodically by
cron(8). When it
is executed it archives log files if necessary. If a log file is determined to
require archiving,
newsyslog rearranges the files so that
“
logfile” is empty,
“
logfile.0
” has the
last period's logs in it,
“
logfile.1
” has the
next to last period's logs in it and so on, up to a user-specified number of
archived logs. Optionally the archived logs can be compressed to save space.
A log can be archived for three reasons:
- It is larger than the configured size (in kilobytes).
- A configured number of hours have elapsed since the log
was last archived.
- The configured time for rotation of the log occurred
within the last 60 minutes.
The granularity of
newsyslog is dependent on how often it is
scheduled to run by
cron(8). It is
recommended that
newsyslog be run once hourly.
When starting up,
newsyslog reads in a configuration file to
determine which logs may potentially be archived. 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 six mandatory fields and three
optional fields, with whitespace separating each field. Blank lines or lines
beginning with “#” are ignored. The fields of the configuration
file are as follows:
-
-
- logfile_name
- Name 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 field may be numeric, or a name which is present in
/etc/passwd or /etc/group. For
backward compatibility, “.” is usable in lieu of
“:”, however use of this feature is discouraged.
-
-
- mode
- Specify the mode of the log file and archives.
-
-
- ngen
- Specify the number of archive files to be kept besides the
log file itself.
-
-
- size
- When the size of the log file reaches
size kilobytes, the log file will be trimmed as
described above. If this field is replaced by an asterisk
(‘
*
’), then the size of the log file
is not taken into account when determining when to trim the log file.
-
-
- when
- The when field can consist of an
interval, a specific time, or both. If the when
field is an asterisk (‘
*
’) log
rotation will depend only on the contents of the
size field. Otherwise, the
when field consists of an optional interval in
hours, optionally followed by an
‘@
’-sign and a
time in a restricted ISO 8601 format or by an
‘$
’-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 interval 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, the log will be trimmed if either condition is
met.
There is no provision for specification of a timezone. There is little point
in specifying an explicit minutes or seconds component in the current
implementation, since the only comparison is `within the hour'.
ISO 8601 restricted time format
The lead-in character for a restricted 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; hence if today is January
22, 1999, the following date specifications 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
‘$
’-sign. The
particular format of day, week and month specification is:
[Dhh],
[Ww[Dhh]]
and
[Mdd[Dhh]]
respectively. Optional time fields default to midnight. 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
- $D23
- rotate every day at 23:00 hr
- $W0D23
- rotate every week on Sunday at 23:00 hr
- $W5D16
- rotate every week on Friday at 16:00 hr
- $MLD0
- rotate at the last day of every month at midnight
- $M5D6
- rotate on every 5th day of month at 6:00 hr
-
-
- flags
- This field specifies any special processing that is
required. These flags are parsed in a case insensitive manner. Individual
flags and their meanings:
-
-
- -
- This flag means nothing - it is used as a spacer when
no flags are set.
-
-
- b
- The file is a binary file or is not in
syslogd(8) format: the
ASCII message which newsyslog inserts to indicate
that the logs have been trimmed should not be included.
-
-
- c
- Create an empty log file if none currently exists.
-
-
- n
- No signal should be sent when the log is trimmed.
-
-
- p
- The first historical log file (i.e. the historical log
file with the suffix “.0”) should not be compressed.
-
-
- j
- Archived log files should be compressed with
bzip2(1) to save
space.
-
-
- x
- Archived log files should be compressed with
xz(1) to save space.
-
-
- z
- Archived log files should be compressed with
gzip(1) to save
space.
-
-
- path_to_pid_file
- This optional field specifies the file name to read to find
the daemon process id. If this field is missing, it defaults to the
/var/run/syslogd.pid file. A signal of type
sigtype is sent to the process id contained in this
path_to_pid_file file. This field must start with
‘/’ in order to be recognized properly.
-
-
- sigtype
- This optional field specifies the type of signal to be sent
to the daemon process. This may be a numeric or symbolic value. By default
a SIGHUP (hang-up) will be sent.
OPTIONS
The following options can be used with newsyslog:
-
-
- -f
config_file
- Use config_file instead of
/etc/newsyslog.conf as the configuration file.
-
-
- -n
- Do not trim the logs, but print out what would be done if
this option were not specified: -n implies
-v.
-
-
- -r
- Remove the restriction that newsyslog
must be running as root. When running as a regular user,
newsyslog will not be able to send a HUP signal to
syslogd(8), so this option
should be used only when debugging or trimming user generated logs.
-
-
- -s
- Do not signal daemon processes.
-
-
- -v
- Run in verbose mode. In this mode each action that is taken
will be printed.
-
-
- -F
- Force trimming of the logs, even if the trim conditions
have not been met. This option is useful for diagnosing system problems by
providing you with fresh logs.
If additional command line arguments are given,
newsyslog will
only examine log files that match those arguments; otherwise, it will examine
all files listed in the configuration file.
FILES
- /etc/newsyslog.conf
- newsyslog configuration file.
SEE ALSO
bzip2(1),
gzip(1),
syslog(3),
syslogd(8)