Module Name: src
Committed By: christos
Date: Fri Apr 17 18:39:31 UTC 2020
Modified Files:
src/external/bsd/cron/dist: crontab.5
Log Message:
Put back the ? syntax accidentally removed when syncing with the OpenBSD
man page.
To generate a diff of this commit:
cvs rdiff -u -r1.7 -r1.8 src/external/bsd/cron/dist/crontab.5
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/external/bsd/cron/dist/crontab.5
diff -u src/external/bsd/cron/dist/crontab.5:1.7 src/external/bsd/cron/dist/crontab.5:1.8
--- src/external/bsd/cron/dist/crontab.5:1.7 Fri Jun 15 19:15:56 2018
+++ src/external/bsd/cron/dist/crontab.5 Fri Apr 17 14:39:31 2020
@@ -1,4 +1,4 @@
-.\" $NetBSD: crontab.5,v 1.7 2018/06/15 23:15:56 wiz Exp $
+.\" $NetBSD: crontab.5,v 1.8 2020/04/17 18:39:31 christos Exp $
.\"
.\"/* Copyright 1988,1990,1993,1994 by Paul Vixie
.\" * All rights reserved
@@ -21,7 +21,7 @@
.\"
.\" $OpenBSD: crontab.5,v 1.36 2018/06/13 13:27:37 jmc Exp $
.\"
-.Dd June 14, 2018
+.Dd April 17, 2020
.Dt CRONTAB 5
.Os
.Sh NAME
@@ -141,12 +141,31 @@ or
Ranges of numbers are allowed.
Ranges are two numbers separated with a hyphen.
The specified range is inclusive.
+.Pp
+A field may begin with a question mark
+.Pq Sq \&? ,
+which indicates a single value randomly selected when the crontab
+file is read.
+If the field contains only a question mark, the value is randomly
+selected from the range of all possible values for the field.
+If the question mark precedes a range, the value is randomly selected
+from the range.
+For example,
+.Dq ? ?2-5 * * *
+specifies that a task will be performed daily between 2:00am and
+and 5:59am at a time randomly selected when the crontab file is
+first read.
+As just one example, this feature can be used to prevent a large
+number of hosts from contacting a server simultaneously and
+overloading it by staggering the time at which a download script
+is executed.
For example,
8\(en11 for an
.Ar hour
entry specifies execution at hours 8, 9, 10 and 11.
.Pp
-Step values can be used in conjunction with ranges.
+Step values can be used in conjunction with ranges (but not random ranges
+which represent a single number).
Following a range with
.No / Ns Ar number
specifies skips of
