Login or Register to Ask a Question and Join Our Community


UNIX for Dummies Questions & Answers

cron problems

 
Thread Tools Search this Thread
Top Forums UNIX for Dummies Questions & Answers cron problems
# 1  
Old 05-01-2012
cron problems
I am trying to setup a cron that runs a script to update my ip for my domain name every time I reboot and checks if my ip changes every 5 minutes and if it does then I update it. I am running Ubuntu server 12.04.

The file /etc/cron.d/ipupdate contains
Code:
# 
#  
#  Run ipupdate
#  

# 
/5 *     * * *     root         /usr/local/bin/ipupdate
@reboot            root         /usr/local/bin/ipupdate

The file /usr/local/bin/ipupdate contains
Code:
#
#Script to enable dynamic IP
#
if [ `ifconfig eth0 | grep 'inet addr:' | cut -d: -f2 | awk '{ print $1}'` != `cat /usr/local/bin/ipchange` ]
then
wget -q -O /dev/null http://freedns.afraid.org/dynamic/update.php?_USERSPECIFIC_
ifconfig eth0 | grep 'inet addr:' | cut -d: -f2 | awk '{ print $1}' > /usr/local/bin/ipchange
echo `date` IP updated to `cat /usr/local/bin/ipchange` >> /home/foo/log
fi
echo `date` IP update finished running >> /home/foo/log

and the /etc/cron.d/ipchange just contains the ip from the last change.

All the above files have been set to give permission to all users (chmod 777) and when I run the script with /usr/local/bin/ipupdate it works how I want it to.
# 2  
Old 05-01-2012
first thing to try when cron is misbehaving is to provide a full pathname to any executables, eg /sbin/ifconfig
This User Gave Thanks to Skrynesaver For This Post:
Bros2
# 3  
Old 05-01-2012
What is in /home/foo/log? The last line of your script should always update that file, even if the if block doesn't execute.

If that log doesn't get updated, it's probably a permission problem.
This User Gave Thanks to ThomasMcA For This Post:
Bros2
# 4  
Old 05-03-2012
Fixed
It is working now. I think the problem was that the change file did not belong to the root user.

Thanks for all the help
 
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. UNIX for Beginners Questions & Answers

Problems with set up Cron

Hi I want to set up a cron for every 15 minutes between some hours. Can you tell whether the below command will work. Getting confuse because my time goes from night to next day morning. i want to setup 8 PM to next day 10 AM. */15 20-10 * * * sh abc.sh (1 Reply)
Discussion started by: raju2016
1 Replies

2. UNIX for Dummies Questions & Answers

Execution Problems with Cron

Good evening, ive got this cron to be run: if i run this manually it doesnt work,it takes me to the prompt again /export/app/CO/opge/scr/Informe_parametros_colombia.ksh >/dev/null 2>&1 here is the code fragment: coopge@coopge: opge PRODUCCION>more... (1 Reply)
Discussion started by: alexcol
1 Replies

3. Shell Programming and Scripting

Execution problems with cron

I am new to creating crontab file , i just wrote below (40 19 * 3 * /root/maths/practisecron.sh), the script just prints "Hi". When ever i save the above file i am getting this . # crontab -e crontab: installing new crontab Can you please check where it went wrong.. (1 Reply)
Discussion started by: vkiyv05
1 Replies

4. Ubuntu

Problems with a .sh file in cron

Hi guys. This is my first post so bear with me. I'm trying to get cron to run a shell script in my home directory (/home/server) that checks the temperature of my HDD. The script works fine, however I can't run it in cron. I've checked the syslog and I have only seen two errors: - Exited with... (11 Replies)
Discussion started by: Rautoner
11 Replies

5. UNIX for Dummies Questions & Answers

Execution Problems with Cron

Hi friends, today i created a cron job , registered the crontab file associated but dont know why the cron is not getting executed at the right time.?? content of Crontab file : 21 15 * * * /subrat/myt i wanted to execute the script myt on 15:21 PM of everyday. the script myt... (2 Replies)
Discussion started by: paras.oriental
2 Replies

6. Shell Programming and Scripting

Execution Problems with Cron

Hi, I have written a shell script to transfer files to a SFTP server passing the filername, source and dest directory as parameters and it runs well. :) I want to schedule this script to run periodically using a cron job. root@pingu # cat /etc/crontab SHELL=/bin/bash... (1 Reply)
Discussion started by: chetancrsp18
1 Replies

7. UNIX and Linux Applications

Execution Problems with Cron

Hi all!! I have a nerve-wracking concept (probably for me!!) which is not understood. My crontab entry looks this way. 33 09 22 3 * /home/myexp.sh "Bgp4 ALL" >/dev/null 2>&1 But cron gets started occasionally. Sometimes it does. Sometimes it does not. And sometimes it hangs in the middle (I... (1 Reply)
Discussion started by: dhivyasuresh
1 Replies

8. Programming

execution problems with cron

how to store a date into file? and how we can access date from the file? ---------- Post updated at 06:09 AM ---------- Previous update was at 06:08 AM ---------- how we can store date in file? (1 Reply)
Discussion started by: causalmodi777
1 Replies

9. UNIX for Dummies Questions & Answers

cron problems

Hi there, this time a have a other problem :) i will start a script over the cron. if i start the script manual (per command) it works without any problems, but over the cron it doesent work. my cron looks like this: 26 15 * * * /path/scriptname.sh 2> /path/error.log there is no... (3 Replies)
Discussion started by: scotty
3 Replies

10. UNIX for Advanced & Expert Users

Cron problems

Hi, I am having a few problems with cron. I have created a shell script (to rotate www logs - this works) and then did the following (as root) #crontab -e 2 0 * * 3 /cron_scripts/wwwlogs.sh ? w ? q # crontab -l entry not shown e.g. it did not show what I had just writern I then... (6 Replies)
Discussion started by: warrend
6 Replies
Login or Register to Ask a Question