09-15-2009
Hi, a new question about crontab.
I have some machine in cluster to avoid interuption in manufacturing process. When one is alive the other one is sleep.
Some time happens to switch between them. So i stop the crontab in one and start it in other one. The question is how can i ensure that the two cron are the same? I made a shell to check the difference in the two /var/spool/cron/crontabs directory and it work fine. When an alarm arrive i manualy align the user crontab file in the sleeping machine using crontab -e. My boss ask to me to do this action automaticaly. Do u think that is correct to align the crontab using the remote copy of the users crontab file? I'm not sure, for instance if i make the user crontab using the vi the shell doesn't start. For the same reason i prefer align the crontab manualy beaside with a shell that make a rcp. That's is correct or do u think that i could be use the rcp between the /var/spool/cron/crontabs files?
Best Regards,
Andrea.
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Why does this cron entry do nothing? It works interactively.
58 23 * * * mydate=`date '+%Y%m%d'`;mv /opt/home/user/file /opt/home/user/file_$mydate (5 Replies)
Discussion started by: steelrose
5 Replies
2. Solaris
HI all,
I would want to schedule a job to run every 2 weeks. In the mean time, i'm only able to schedule on every week. Is it possible to schedule 2 weeks on crontab?
Thank you. (3 Replies)
Discussion started by: *Jess*
3 Replies
3. UNIX for Dummies Questions & Answers
I set up a job to run a script in a certain directory to remove certain files. The script seems to run as my logs indicate but nothing happens. If I run the script manually then it removes the correct files. I'm now wondering if crontab doesnt have access to remove files from the directory I'm... (9 Replies)
Discussion started by: NycUnxer
9 Replies
4. AIX
My question is how to specify the one-time execution of a shell script in crontab?
For example: If I wanted to schedule shell "Test.sh" for one-time execution on December 13 at 8:00AM would it be as follows?
00 08 13 12 6 /usr/datatools/dtbackups/Test.sh > /usr/u/sybase_12.5/logs/Test.log &... (3 Replies)
Discussion started by: Alan.AIX
3 Replies
5. UNIX for Dummies Questions & Answers
Hello guys,
I have a server with Red Hat Enterprise Linux AS release 4 (Nahant Update 5), there i have a lot of users, im the root. I need to lock the use of crontab to the users, i mean, i dont want to give to the users the option to creat any crontab line, how can i do that?
I tried to... (4 Replies)
Discussion started by: lestat_ecuador
4 Replies
6. Shell Programming and Scripting
I have a user (xxx) who is allowed to run cron jobs when a job is
launched from cron is the .profile sourced in? I am not sure it is so I setup a cron job as this user to do the following:
35 15 * * 0-5 su - xxx -c "ksh ls -lt /tmp" > /tmp.out
and I am seeing the following error (see... (2 Replies)
Discussion started by: BeefStu
2 Replies
7. Solaris
I want to run a script on (say) the 4th friday every month. But if I include this line in the crontab :
45 9 22-28 * 5 echo '4th Friday'|mailx -s "Fri week 4" mike
it sends me mail if the date is 22-28, OR the day is friday. So I get mail every day for a week , and also every friday.
I... (2 Replies)
Discussion started by: mikejordan
2 Replies
8. UNIX for Dummies Questions & Answers
Hey out there
This is all I have in my crontab file. I know the crontab works because it was already out there and working. I simply replaced the existing with my line of code below to see if it worked. I uploaded 6 month old pdf files in this directory, stopped/started all the scripts that... (3 Replies)
Discussion started by: vsekvsek
3 Replies
9. Shell Programming and Scripting
I need to run an script every 10th and 25th day in every month at 11pm.
the script name is /home/ss/automated.sh
I tried to execute the script every day and everytime with the below syntax. its not executing it from crontab.
* * * * * /home/ss/automated.sh
Any idea why it not... (6 Replies)
Discussion started by: ramkumar15
6 Replies
10. Shell Programming and Scripting
Hello,
I have scheduled the execution of a file (delete_oldv02) every hour with crontab and it works perfectly. See below the instruction written.
0 */1 * * * /home/delete_oldv02 >>/home/delete_oldv02.log
My first question is if I can add one more line to crontab.
I also would like to... (5 Replies)
Discussion started by: dcaccount
5 Replies
LEARN ABOUT PLAN9
crontab
CRONTAB(1) General Commands Manual CRONTAB(1)
NAME
crontab - maintain crontab files for individual users (Vixie Cron)
SYNOPSIS
crontab [ -u user ] file
crontab [ -u user ] [ -i ] { -e | -l | -r }
DESCRIPTION
crontab is the program used to install, deinstall or list the tables used to drive the cron(8) daemon in Vixie Cron. Each user can have
their own crontab, and though these are files in /var/spool/cron/crontabs, they are not intended to be edited directly.
If the /etc/cron.allow file exists, then you must be listed (one user per line) therein in order to be allowed to use this command. If the
/etc/cron.allow file does not exist but the /etc/cron.deny file does exist, then you must not be listed in the /etc/cron.deny file in order
to use this command.
If neither of these files exists, then depending on site-dependent configuration parameters, only the super user will be allowed to use
this command, or all users will be able to use this command.
If both files exist then /etc/cron.allow takes precedence. Which means that /etc/cron.deny is not considered and your user must be listed
in /etc/cron.allow in order to be able to use the crontab.
Regardless of the existance of any of these files, the root administrative user is always allowed to setup a crontab. For standard Debian
systems, all users may use this command.
If the -u option is given, it specifies the name of the user whose crontab is to be used (when listing) or modified (when editing). If this
option is not given, crontab examines "your" crontab, i.e., the crontab of the person executing the command. Note that su(8) can confuse
crontab and that if you are running inside of su(8) you should always use the -u option for safety's sake.
The first form of this command is used to install a new crontab from some named file or standard input if the pseudo-filename ``-'' is
given.
The -l option causes the current crontab to be displayed on standard output. See the note under DEBIAN SPECIFIC below.
The -r option causes the current crontab to be removed.
The -e option is used to edit the current crontab using the editor specified by the VISUAL or EDITOR environment variables. After you exit
from the editor, the modified crontab will be installed automatically. If neither of the environment variables is defined, then the default
editor /usr/bin/editor is used.
The -i option modifies the -r option to prompt the user for a 'y/Y' response before actually removing the crontab.
DEBIAN SPECIFIC
The "out-of-the-box" behaviour for crontab -l is to display the three line "DO NOT EDIT THIS FILE" header that is placed at the beginning
of the crontab when it is installed. The problem is that it makes the sequence
crontab -l | crontab -
non-idempotent -- you keep adding copies of the header. This causes pain to scripts that use sed to edit a crontab. Therefore, the default
behaviour of the -l option has been changed to not output such header. You may obtain the original behaviour by setting the environment
variable CRONTAB_NOHEADER to 'N', which will cause the crontab -l command to emit the extraneous header.
SEE ALSO
crontab(5), cron(8)
FILES
/etc/cron.allow
/etc/cron.deny
/var/spool/cron/crontabs
There is one file for each user's crontab under the /var/spool/cron/crontabs directory. Users are not allowed to edit the files under that
directory directly to ensure that only users allowed by the system to run periodic tasks can add them, and only syntactically correct
crontabs will be written there. This is enforced by having the directory writable only by the crontab group and configuring crontab com-
mand with the setgid bid set for that specific group.
STANDARDS
The crontab command conforms to IEEE Std1003.2-1992 (``POSIX''). This new command syntax differs from previous versions of Vixie Cron, as
well as from the classic SVR3 syntax.
DIAGNOSTICS
A fairly informative usage message appears if you run it with a bad command line.
cron requires that each entry in a crontab end in a newline character. If the last entry in a crontab is missing the newline, cron will
consider the crontab (at least partially) broken and refuse to install it.
AUTHOR
Paul Vixie <paul@vix.com> is the author of cron and original creator of this manual page. This page has also been modified for Debian by
Steve Greenland, Javier Fernandez-Sanguino and Christian Kastner.
4th Berkeley Distribution 19 April 2010 CRONTAB(1)