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CRON.NLM
version 1.7 (NetWare v3.12, v4.x, and IntraNetWare)
Copyright (C) 1997 Novell, Inc.
All Rights Reserved
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CONTENTS
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I. Abstract
II. Installation Instructions
III. Usage
IV. Product Description
V. Enhancements/Bug Fixes
VI. Known Issues
VII. Frequently Asked Questions
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I. ABSTRACT
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Cron schedules commands to be executed on a NetWare server at
specified dates and times.
NOTE: This utility helps system administrators. It is provided
free of charge as a courtesy, and therefore, is not a Novell
supported product.
NOTE: For more advanced scheduling capabilities on a NetWare
server you can purchase third-party scheduling utilities.
For more information refer to the following web pages:
http://www.avanti-tech.com/taskmstr/tm_main.html.
http://www.classic.com
Novell does not support nor endorse these utilities.
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II. INSTALLATION INSTRUCTIONS
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Copy CRON.NLM to the SYS:\SYSTEM directory on your server.
For NetWare 3.x:
Copy CRON.MSG to the SYS:\SYSTEM directory on your server.
NOTE: You MUST have CLIB.NLM and AFTER311.NLM from LIB312x.EXE
(http://support.novell.com/misc/patlst.htm
under the "NetWare 3.12" section)
For IntranetWare and NetWare 4.x:
Copy CRON.MSG to SYS:\SYSTEM\NLS\<LANGUAGE NUMBER>
For example, if you have the English message file you would
copy CRON.MSG to SYS:\SYSTEM\NLS\4.
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III. USAGE
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load cron [logfile size]
Logfile size specifies the size the logfile will reach before
restarting. This keeps the logfile from getting too large and
crashing the SYS volume. The default is 5 MB (5000000).
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IV. PRODUCT DESCRIPTION
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CRON.NLM is adapted from the well-known Unix clock daemon. Cron
runs all day, spending most of its time asleep. Once a minute it
wakes up and reads SYS:\ETC\CRONTAB. Any commands scheduled in
CRONTAB matching the current date and time are executed.
Cron records all actions in the log file SYS:\ETC\CRONLOG.
CRONTAB SYNTAX:
Each crontab entry has six fields, each separated by tabs or
spaces:
minute hour day-of-month month day-of-week command
Each entry is checked in turn, and any entry matching the current
time is executed. The entry * matches anything. A pound sign
(#) is a comment. Valid values are:
minute(0-59)
hour(0-23)
day-of-month(1-31)
month(1-12)
day-of-week(0-6) Note: week starts with 0=Sunday
Examples:
#Min Hr Dat Mo Day Command
#print time every minute
* * * * * time
#print volumes on the hour
0 * * * * volumes
#do backup Mon-Fri at 0430
30 4 * * 1-5 load sbackup
#Start Oracle database every morning at 7:00 a.m.
#Stop Oracle database every Sunday at 7:45 p.m.
0 7 * * * orastart
45 19 * * 0 orastop
#Mon, Wed, Fri at 1930 down server
30 19 * * 1,3,5 down
#Xmas morning at 0900 only
0 9 25 12 * load sing
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V. ENHANCEMENTS/BUG FIXES
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Enhancements to version 1.1:
- Enhanced to removed the 2K size limit for CRONTAB.
Enhancements to version 1.3:
- Enhanced checking of scheduling parameters in CRONTAB.
- Enhanced to execute commands on the minute mark.
- Enhanced to spawn NLMs rather than feeding them to the
keyboard buffer. All other commands are still fed to
the keyboard buffer.
- Fixed shutdown routine so that CRON can unload itself.
Bug Fixes to version 1.5:
- Whitespace before command were not being removed.
- When "Load <NLM>" is specified, the arguments were not being parsed correctly.
Bug Fixes to version 1.6:
- Month was corrected to check between Jan (1) and December (12). Previously
December could not be selected.
Enhancements to version 1.7:
- Cron was enabled for localization. It must now be accompanied by a .MSG file
which contains language specific messages.
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VI. KNOWN ISSUES
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Issue 1 - The keyboard buffer is stuffed with the command so anyone typing
on the console at the time will have their keystrokes interrupted.
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VII. FREQUENTLY ASKED QUESTIONS
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Q: I try to load CRON on NetWare 3.12 and get a message like
"Loader cannot find public symbol: LoadLanguageMessageTable"
OR
"Loader cannot find public symbol: NWfprinf"
A: These messages occur when older verison of CLIB.NLM
and AFTER311.NLM are being used. You need to download the
latest version of these NLMs. They are both found in LIB312x.EXE
(http://support.novell.com/misc/patlst.htm under the "NetWare 3.12" section)
After these two NLMs have been installed load AFTER311.NLM before
trying to load CRON.
Q: I get the message "Can't access crontab". What does this
mean?
A: CRON does NOT create a file named CRONTAB; you must do that.
CRONTAB is a text file that must exist in SYS:\ETC and have
NO extension (NOT CRONTAB.TXT).
Q: How do I create CRONTAB?
A: With your favorite text editor, write the commands and
save the file as SYS:\ETC\CRONTAB. Some text editors
automatically add a .TXT extension. This is bad. Remove it.
Q: Can I run DOS commands or DOS batch files?
A: Cron can execute any command that is currently available from the
NetWare server such as loading NLMs or server console commands. It does
not provide DOS shell-like functionality.
Q: Some NLMs stay loaded even when they have completed. The next
time Cron tries to load it, it will give a "non-re-entrant"
error. How can I unload them?
A: Some NLMs have command-line options for auto-unloading. If
not, you can schedule an unload command one minute before the
load command. For example, if you want XYZBACK.NLM to run EVERY
night at 3:00 am, you would use "0 3 * * * load xyzback" in
CRONTAB. Unfortunately, xyzback requires a manual shutdown. It
ran fine early Friday morning, but because the administrator
didn't unload xyzback, the server could not load it fresh again
early Saturday and Sunday mornings. A new command needs to go in
CRONTAB: "59 2 * * * unload xyzback".
Q: Can I redirect NLM output to keep status reports?
A: Although you get a status report of cron in CRONLOG, you can
NOT get output from any NLM that cron schedules.
Novell Products and versions
NetWare 3.12
NetWare 4.1
NetWare 4.11
NetWare 4.2
NetWare 5
NetWare for Small Business 4.11
NetWare for Small Business 4.2
Novell Small Business Suite 5
intraNetWare 4.11
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