I have the following questions about crontab file :
1) In crontab file I got the folllowing output :
I know that the file under cron.hourly/daily/weekly are system specific executables file . Then If I want to keep a manual script like (test.sh) into cron.daily and i want it runs at 10:00 am everyday, so I edit the crontab file :
But the script(test.sh) is not working .
Now my question , is it not possible to run the manual scirpt (not system specific) using cron.daily or cron.hourly directory ? or it is only used for system specific executables file ? Hope I have to clear my question .
2) What is the function of 'run-parts' command .
3)
In the below crontab line :
what is meaning of 5 ? it it 5 sec or 5 min
Waiting for ur kind reply ... ...
Last edited by pludi; 10-14-2009 at 04:06 AM..
Reason: code tags, please...
I'm trying to create a crontab entry that will run the who command once per hour Monday-Friday. Any command output should be appended to the file whoison.log in my home directory.
This is what I wrote:
crontab 0 * * * 1-5 who >> /home/myhome/whoison.log
Did I do this right?
Thanks (7 Replies)
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)
Hello,
Does anybody know of a way to add an entry to the crontab without executing >crontab -e? I'm running a script that would add a line without any user intervention. The only way I could think of would to use sed to add the line to the end of the cron file, but I don't know if this would... (3 Replies)
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)
Hello,
When I do a crontab -l I get the following listing:
# crontab -l
# DO NOT EDIT THIS FILE - edit the master and reinstall.
# (/tmp/crontab.13826 installed on Thu Jun 23 10:13:18 2005)
# (Cron version -- $Id: crontab.c,v 2.13 1994/01/17 03:20:37 vixie Exp $)
#0 1 * * * scp... (6 Replies)
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)
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)
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)
If I want to run a process every 30 mins except for 3-4 where I want to run
every 5 mins I know I can do this with 3 entries.
30 5-23 * * * "echo "Hello"
30 0-3 * * * "echo "Hello"
5,10,15,20,25,30,35,40,45,50,55 3-4, * * * "echo Hello"
Can this be done with less entries (4 Replies)
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 CENTOS
crontab
CRONTAB(1) User Commands CRONTAB(1)NAME
crontab - maintains crontab files for individual users
SYNOPSIS
crontab [-u user] file
crontab [-u user] [-l | -r | -e] [-i] [-s]
crontab -n [ hostname ]
crontab -c
DESCRIPTION
Crontab is the program used to install, remove or list the tables used to serve the cron(8) daemon. Each user can have their own crontab,
and though these are files in /var/spool/, they are not intended to be edited directly. For SELinux in MLS mode, you can define more
crontabs for each range. For more information, see selinux(8).
In this version of Cron it is possible to use a network-mounted shared /var/spool/cron across a cluster of hosts and specify that only one
of the hosts should run the crontab jobs in the particular directory at any one time. You may also use crontab(1) from any of these hosts
to edit the same shared set of crontab files, and to set and query which host should run the crontab jobs.
Running cron jobs can be allowed or disallowed for different users. For this purpose, use the cron.allow and cron.deny files. If the
cron.allow file exists, a user must be listed in it to be allowed to use cron If the cron.allow file does not exist but the cron.deny file
does exist, then a user must not be listed in the cron.deny file in order to use cron. If neither of these files exists, only the super
user is allowed to use cron. Another way to restrict access to cron is to use PAM authentication in /etc/security/access.conf to set up
users, which are allowed or disallowed to use crontab or modify system cron jobs in the /etc/cron.d/ directory.
The temporary directory can be set in an environment variable. If it is not set by the user, the /tmp directory is used.
OPTIONS -u Appends the name of the user whose crontab is to be modified. If this option is not used, crontab examines "your" crontab, i.e.,
the crontab of the person executing the command. Note that su(8) may confuse crontab, thus, when executing commands under su(8) you
should always use the -u option. If no crontab exists for a particular user, it is created for him the first time the crontab -u
command is used under his username.
-l Displays the current crontab on standard output.
-r Removes the current crontab.
-e Edits 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.
-i This option modifies the -r option to prompt the user for a 'y/Y' response before actually removing the crontab.
-s Appends the current SELinux security context string as an MLS_LEVEL setting to the crontab file before editing / replacement occurs
- see the documentation of MLS_LEVEL in crontab(5).
-n This option is relevant only if cron(8) was started with the -c option, to enable clustering support. It is used to set the host in
the cluster which should run the jobs specified in the crontab files in the /var/spool/cron directory. If a hostname is supplied,
the host whose hostname returned by gethostname(2) matches the supplied hostname, will be selected to run the selected cron jobs
subsequently. If there is no host in the cluster matching the supplied hostname, or you explicitly specify an empty hostname, then
the selected jobs will not be run at all. If the hostname is omitted, the name of the local host returned by gethostname(2) is
used. Using this option has no effect on the /etc/crontab file and the files in the /etc/cron.d directory, which are always run,
and considered host-specific. For more information on clustering support, see cron(8).
-c This option is only relevant if cron(8) was started with the -c option, to enable clustering support. It is used to query which
host in the cluster is currently set to run the jobs specified in the crontab files in the directory /var/spool/cron , as set using
the -n option.
SEE ALSO crontab(5), cron(8)FILES
/etc/cron.allow
/etc/cron.deny
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
An informative usage message appears if you run a crontab with a faulty command defined in it.
AUTHOR
Paul Vixie <vixie@isc.org>
Colin Dean <colin@colin-dean.org>
cronie 2012-11-22 CRONTAB(1)