1.\" This file contains changes from the Open Software Foundation. 2.\" 3.\" Copyright 1988, 1989 by the Massachusetts Institute of Technology 4.\" 5.\" Permission to use, copy, modify, and distribute this software 6.\" and its documentation for any purpose and without fee is 7.\" hereby granted, provided that the above copyright notice 8.\" appear in all copies and that both that copyright notice and 9.\" this permission notice appear in supporting documentation, 10.\" and that the names of M.I.T. and the M.I.T. S.I.P.B. not be 11.\" used in advertising or publicity pertaining to distribution 12.\" of the software without specific, written prior permission. 13.\" M.I.T. and the M.I.T. S.I.P.B. make no representations about 14.\" the suitability of this software for any purpose. It is 15.\" provided "as is" without express or implied warranty. 16.\" 17.Dd September 22, 2025 18.Dt NEWSYSLOG 8 19.Os 20.Sh NAME 21.Nm newsyslog 22.Nd maintain system log files to manageable sizes 23.Sh SYNOPSIS 24.Nm 25.Op Fl CFNPnrsv 26.Op Fl a Ar directory 27.Op Fl d Ar directory 28.Op Fl f Ar config_file 29.Op Fl I Ar signal 30.Op Fl S Ar pidfile 31.Op Fl t Ar timefmt 32.Op Oo Fl R Ar tagname Oc Ar 33.Sh DESCRIPTION 34The 35.Nm 36utility should be scheduled to run periodically by 37.Xr cron 8 . 38When it is executed it archives log files if necessary. 39If a log file 40is determined to require archiving, 41.Nm 42rearranges the files so that 43.Dq Va logfile 44is empty, 45.Dq Va logfile Ns Li \&.0 46has 47the last period's logs in it, 48.Dq Va logfile Ns Li \&.1 49has the next to last 50period's logs in it, and so on, up to a user-specified number of 51archived logs. 52It is also possible to let archived log filenames be created using the 53time the log file was archived instead of the sequential number using 54the 55.Fl t 56option. 57Optionally the archived logs can be compressed to save 58space. 59.Pp 60A log can be archived for three reasons: 61.Bl -enum -offset indent 62.It 63It is larger than the configured size (in kilobytes). 64.It 65A configured number of hours have elapsed since the log was last 66archived. 67.It 68This is the specific configured hour for rotation of the log. 69.El 70.Pp 71The granularity of 72.Nm 73is dependent on how often it is scheduled to run by 74.Xr cron 8 . 75Since the program is quite fast, it may be scheduled to run every hour 76without any ill effects, 77and mode three (above) assumes that this is so. 78.Sh OPTIONS 79The following options can be used with 80.Nm : 81.Bl -tag -width indent 82.It Fl f Ar config_file 83Instruct 84.Nm 85to use 86.Ar config_file 87instead of 88.Pa /etc/newsyslog.conf 89for its configuration file. 90.It Fl a Ar directory 91Specify a 92.Ar directory 93into which archived log files will be written. 94If a relative path is given, 95it is appended to the path of each log file 96and the resulting path is used as the directory 97into which the archived log for that log file will be written. 98If an absolute path is given, 99all archived logs are written into the given 100.Ar directory . 101If any component of the path 102.Ar directory 103does not exist, 104it will be created when 105.Nm 106is run. 107.It Fl d Ar directory 108Specify a 109.Ar directory 110which all log files will be relative to. 111To allow archiving of logs outside the root, the 112.Ar directory 113passed to the 114.Fl a 115option is unaffected. 116.It Fl v 117Place 118.Nm 119in verbose mode. 120In this mode it will print out each log and its 121reasons for either trimming that log or skipping it. 122.It Fl n 123Cause 124.Nm 125not to trim the logs, but to print out what it would do if this option 126were not specified. 127This option implies the 128.Fl r 129option. 130.It Fl r 131Remove the restriction that 132.Nm 133must be running as root. 134Of course, 135.Nm 136will not be able to send a signal to 137.Xr syslogd 8 138so this option should only be used in debugging. 139.It Fl s 140Specify that 141.Nm 142should not send any signals to any daemon processes that it would 143normally signal when rotating a log file. 144For any log file which is rotated, this option will usually also 145mean the rotated log file will not be compressed if there is a 146daemon which would have been signalled without this option. 147However, this option is most likely to be useful when specified 148with the 149.Fl R 150option, and in that case the compression will be done. 151.It Fl t Ar timefmt 152If specified 153.Nm 154will create the 155.Dq rotated 156logfiles using the specified time format instead of the default 157sequential filenames. 158The filename used will be kept until it is deleted. 159The time format is described in the 160.Xr strftime 3 161manual page. 162If the 163.Ar timefmt 164argument is set to an empty string or the string 165.Dq DEFAULT , 166the default built in time format 167is used. 168If the 169.Ar timefmt 170string is changed the old files created using the previous time format 171will not be automatically removed (unless the new format is very 172similar to the old format). 173This is also the case when changing from sequential filenames to time 174based file names, and the other way around. 175The time format should contain at least year, month, day, and hour to 176make sure rotating of old logfiles can select the correct logfiles. 177.It Fl C 178If specified once, then 179.Nm 180will create any log files which do not exist, and which have the 181.Sy C 182flag specified in their config file entry. 183If specified multiple times, then 184.Nm 185will create all log files which do not already exist. 186If log files are given on the command-line, then the 187.Fl C 188or 189.Fl CC 190will only apply to those specific log files. 191.It Fl F 192Force 193.Nm 194to trim the logs, even if the trim conditions have not been met. 195This 196option is useful for diagnosing system problems by providing you with 197fresh logs that contain only the problems. 198.It Fl N 199Do not perform any rotations. 200This option is intended to be used with the 201.Fl C 202or 203.Fl CC 204options when creating log files is the only objective. 205.It Fl P 206Prevent further action if we should send signal but the 207.Dq pidfile 208is empty or does not exist. 209.It Fl R Ar tagname 210Specify that 211.Nm 212should rotate a given list of files, even if trim conditions are not 213met for those files. 214The 215.Ar tagname 216is only used in the messages written to the log files which are 217rotated. 218This differs from the 219.Fl F 220option in that one or more log files must also be specified, so that 221.Nm 222will only operate on those specific files. 223This option is mainly intended for the daemons or programs which write 224some log files, and want to trigger a rotate based on their own criteria. 225With this option they can execute 226.Nm 227to trigger the rotate when they want it to happen, and still give the 228system administrator a way to specify the rules of rotation (such as how 229many backup copies are kept, and what kind of compression is done). 230When a daemon does execute 231.Nm 232with the 233.Fl R 234option, it should make sure all of the log files are closed before 235calling 236.Nm , 237and then it should re-open the files after 238.Nm 239returns. 240Usually the calling process will also want to specify the 241.Fl s 242option, so 243.Nm 244will not send a signal to the very process which called it to force 245the rotate. 246Skipping the signal step will also mean that 247.Nm 248will return faster, since 249.Nm 250normally waits a few seconds after any signal that is sent. 251.It Fl I Ar signal 252Specify signal to send for entries that do not have signal configured. 253This option accepts either a signal number or a name as argument. 254The default value is HUP. 255.It Fl S Ar pidfile 256Use 257.Ar pidfile 258as 259.Xr syslogd 8 Ns 's 260pidfile. 261.El 262.Pp 263If additional command line arguments are given, 264.Nm 265will only examine log files that match those arguments; otherwise, it 266will examine all files listed in the configuration file. 267.Sh FILES 268.Bl -tag -width /usr/local/etc/newsyslog.conf.d -compact 269.It Pa /etc/newsyslog.conf 270.Nm 271configuration file 272.It Pa /etc/newsyslog.conf.d 273By default each file in this directory ending in '.conf' and not beginning with 274a '.' will be included by the default 275.Pa newsyslog.conf . 276.It Pa /usr/local/etc/newsyslog.conf.d 277By default each file in this directory ending in '.conf' and not beginning with 278a '.' will be included by the default 279.Pa newsyslog.conf . 280.El 281.Sh COMPATIBILITY 282Previous versions of the 283.Nm 284utility used the dot (``.'') character to 285distinguish the group name. 286Beginning with 287.Fx 3.3 , 288this has been changed to a colon (``:'') character so that user and group 289names may contain the dot character. 290The dot (``.'') character is still 291accepted for backwards compatibility. 292.Sh SEE ALSO 293.Xr bzip2 1 , 294.Xr gzip 1 , 295.Xr xz 1 , 296.Xr zstd 1 , 297.Xr syslog 3 , 298.Xr newsyslog.conf 5 , 299.Xr chown 8 , 300.Xr syslogd 8 301.Sh HISTORY 302The 303.Nm 304utility originated from 305.Nx 306and first appeared in 307.Fx 2.2 . 308.Sh AUTHORS 309.An Theodore Ts'o , 310MIT Project Athena 311.Pp 312Copyright 1987, Massachusetts Institute of Technology 313