The crontab entry looks okay, but there's lots wrong with your script.
Technically the name doesn't matter but shell scripts are usually .sh, not .txt. It being named .txt makes me wonder if you set it executable -- if it's not, cron can't run it. chmod +x crontab.sh
The first line in any shell script should be a #! line telling it what shell to use, like this:
Also, cron's path is pretty minimal, way more than a users', so might not know where to find tcpdump. You can [icode]. /etc/profile[icode] to read in a more usual profile before you try and run things.
You're missing a space between -w and the filename. You should also tell it exactly where to put them since cron may run things where you expect it to.
Having a script still running for hours on end may prevent root's crontab from running anything else during that time. If you put the command into the background, the shell will return immediately and cron won't have to wait for it. (If it hangs, cron will end up creating one more hanging tcpdump process per day, heh.)
So:
Last edited by Corona688; 04-14-2011 at 07:57 PM..
Hello!
my crontab -e dosent work. Im getting this error message:
sh: VI: not found
The crontab files was not changed.
How do i make it work? I think you should use "export editor=vi"
or something. But i cant seem to get the correct line!
pleas help... (11 Replies)
Not sure what has changed in the Unix environment.
The following script which was working is now not working.
#!/usr/bin/ksh
# -----------------------------------------------------------------------------
# File: monitor_db.sh
#
#... (1 Reply)
Hi All,
I have created crontab using following steps-
1) crontab -e
(edited the file with) 0 10 * * 1-5 /home/user01/exercise/cron.sh
2) then saved this file with :wq
3) cron.sh contains the code-
#!/bin/bash
DAY=`date +%a`
mkdir abc_${DAY}
4) done the execut permision... (3 Replies)
Hello,
My question is very basic for the settings to SSH my home PC from work.
Home network two PC:
Internet comes into my house through ISP modem and then the two PCs are connected with the router (Trendnet). The IPs for my PCs are
How to set other stuffs for me to access my home PC from... (5 Replies)
Hi,
0 9 1,2,3,4,5,6,7 3,4 6
I want a cronjob to run on every 1st Sat of Mar & Apr. But the above schedule is running is running on the 1st 7 days. How do i rectify it?
Thanks in advance. (2 Replies)
Hi, i wanted to schedule a backup script to run on 7.30pm every 1st Sat of month MAR, APR, SEP, OCT.
Am i understanding it correctly? Because it doesn't seem to run according to the schedule i needed.
= (7.30pm) & (1st to 7th day of the month) & (MAR, APR, SEP, OCT) & (Sat)
30 19 1-7... (1 Reply)
Hi Team,
Please help me to set one script in crontab.
I have one script and inside script, its creating one log file for saving ouptut of script. i have to out that script in crontab. When i put the script in cronatab, it executed and log file created but no data in log.
like this i put in... (3 Replies)
Hi All,
Can anyone tell me how to schedule the dbshell.sh script to run on sunday.
I have scheduled as 1 19 7 * * /home/svr/dbshell.sh. kindly confirm confirm whether coded "7" or it should set to '0'.
unix:$ crontab -l
0 19 6 * * /home/svr/dbemail.sh
1 19 7 * * /home/svr/dbshell.sh (2 Replies)
Hello,
Here is my crontab
# Reboot one Sunday out of 2 at 02:00
0 2 * * 0/2 /usr/bin/reboot
2017-04-16
2017-04-23
2017-04-30
and so on
I tested my crontab here, it seems to work
Http://cron.schlitt.info/index.php?c...=100&test=Test
However on my distrib linux mageďa
When I register... (4 Replies)
Discussion started by: amazigh42
4 Replies
LEARN ABOUT SUSE
cron
CRON(8) System Manager's Manual CRON(8)NAME
cron - daemon to execute scheduled commands (ISC Cron V4.1)
SYNOPSIS
cron [-l load_avg] [-n]
DESCRIPTION
Cron should be started from /etc/rc or /etc/rc.local. It will return immediately, so you don't need to start it with '&'. The -n option
changes this default behavior causing it to run in the foreground. This can be useful when starting it out of init.
Cron searches /var/spool/cron for crontab files which are named after accounts in /etc/passwd; crontabs found are loaded into memory. Cron
also searches for /etc/crontab and the files in the /etc/cron.d directory, which are in a different format (see crontab(5)). Cron then
wakes up every minute, examining all stored crontabs, checking each command to see if it should be run in the current minute. When execut-
ing commands, any output is mailed to the owner of the crontab (or to the user named in the MAILTO environment variable in the crontab, if
such exists).
Additionally, cron checks each minute to see if its spool directory's modtime (or the modtime on /etc/crontab) has changed, and if it has,
cron will then examine the modtime on all crontabs and reload those which have changed. Thus cron need not be restarted whenever a crontab
file is modified. Note that the Crontab(1) command updates the modtime of the spool directory whenever it changes a crontab.
Daylight Saving Time and other time changes
Local time changes of less than three hours, such as those caused by the start or end of Daylight Saving Time, are handled specially. This
only applies to jobs that run at a specific time and jobs that are run with a granularity greater than one hour. Jobs that run more fre-
quently are scheduled normally.
If time has moved forward, those jobs that would have run in the interval that has been skipped will be run immediately. Conversely, if
time has moved backward, care is taken to avoid running jobs twice.
Time changes of more than 3 hours are considered to be corrections to the clock or timezone, and the new time is used immediately.
PAM Access Control
On SUSE LINUX systems, crond now supports access control with PAM - see pam(8). A PAM configuration file for crond is installed in
/etc/pam.d/crond . crond loads the PAM environment from the pam_env module, but these can be overriden by settings in the crontab file.
SIGNALS
On receipt of a SIGHUP, the cron daemon will close and reopen its log file. This is useful in scripts which rotate and age log files.
Naturally this is not relevant if cron was built to use syslog(3).
CAVEATS
In this version of cron, /etc/crontab must not be writable by any user other than root. No crontab files may be links, or linked to by any
other file. No crontab files may be executable, or be writable by any user other than their owner.
SEE ALSO crontab(1), crontab(5), pam(8)AUTHOR
Paul Vixie <vixie@isc.org>
4th Berkeley Distribution 10 January 1996" CRON(8)