projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 693d8207 GR |
1 | .\"/* Copyright 1988,1990,1993 by Paul Vixie |
| 2 | .\" * All rights reserved | |
| 3 | .\" * | |
| 4 | .\" * Distribute freely, except: don't remove my name from the source or | |
| 5 | .\" * documentation (don't take credit for my work), mark your changes (don't | |
| 6 | .\" * get me blamed for your possible bugs), don't alter or remove this | |
| 7 | .\" * notice. May be sold if buildable source is provided to buyer. No | |
| 8 | .\" * warrantee of any kind, express or implied, is included with this | |
| 9 | .\" * software; use at your own risk, responsibility for damages (if any) to | |
| 10 | .\" * anyone resulting from the use of this software rests entirely with the | |
| 11 | .\" * user. | |
| 12 | .\" * | |
| 13 | .\" * Send bug reports, bug fixes, enhancements, requests, flames, etc., and | |
| 14 | .\" * I'll try to keep a version up to date. I can be reached as follows: | |
| 15 | .\" * Paul Vixie <paul@vix.com> uunet!decwrl!vixie!paul | |
| 16 | .\" */ | |
| 17 | .\" | |
| 18 | .\" $Header: $ | |
| 19 | .\" | |
| 20 | .\" From Id: cron.8,v 2.2 1993/12/28 08:34:43 vixie Exp | |
| 21 | .\" | |
| 22 | .TH CRON 8 "20 December 1993" | |
| 23 | .UC 4 | |
| 24 | .SH NAME | |
| 25 | cron \- daemon to execute scheduled commands (Vixie Cron) | |
| 26 | .SH SYNOPSIS | |
| 27 | cron | |
| 28 | .SH DESCRIPTION | |
| 29 | .I Cron | |
| 30 | should be started from /etc/rc or /etc/rc.local. It will return immediately, | |
| 31 | so you don't need to start it with '&'. | |
| 32 | .PP | |
| 33 | .I Cron | |
| 34 | searches /var/cron/tabs for crontab files which are named after accounts in | |
| 35 | /etc/passwd; crontabs found are loaded into memory. | |
| 36 | .I Cron | |
| 37 | also searches for /etc/crontab which is in a different format (see | |
| 38 | .IR crontab(5)). | |
| 39 | .I Cron | |
| 40 | then wakes up every minute, examining all stored crontabs, checking each | |
| 41 | command to see if it should be run in the current minute. When executing | |
| 42 | commands, any output is mailed to the owner of the crontab (or to the user | |
| 43 | named in the MAILTO environment variable in the crontab, if such exists). | |
| 44 | .PP | |
| 45 | Additionally, | |
| 46 | .I cron | |
| 47 | checks each minute to see if its spool directory's modtime (or the modtime | |
| 48 | on | |
| 49 | .IR /etc/crontab) | |
| 50 | has changed, and if it has, | |
| 51 | .I cron | |
| 52 | will then examine the modtime on all crontabs and reload those which have | |
| 53 | changed. Thus | |
| 54 | .I cron | |
| 55 | need not be restarted whenever a crontab file is modified. Note that the | |
| 56 | .IR Crontab (1) | |
| 57 | command updates the modtime of the spool directory whenever it changes a | |
| 58 | crontab. | |
| 59 | .SH "SEE ALSO" | |
| 60 | crontab(1), crontab(5) | |
| 61 | .SH AUTHOR | |
| 62 | .nf | |
| 63 | Paul Vixie <paul@vix.com> |