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