Cron is a job scheduler that allows users to run commands periodically.
5
votes
3answers
1k views
Frustrating issue where neither cron nor su -c runs my job (permissions?)
Updated (and snipped) with more details below.
I've set up a cron script and I'm trying to debug why it's not running. [Snipped context testing, which is all ok; see revision 2 for details] The ...
3
votes
4answers
326 views
command for counting number of active cron jobs in crontabs
Problem statement
I have 5 solaris boxes, some have Solaris 10 and some have Solaris 9.
All of them have many cronjobs in their crontabs.
I would like to know number of active cronjobs available, so ...
2
votes
2answers
315 views
Is crontab related to server performance?
I am using Solaris 10, and I am adding many cronjobs to my server's crontab.
Currently I have 30 cronjobs in my crontab.
one cronjob takes 8 hours to complete ,one other cron job takes 5 hours to ...
11
votes
2answers
550 views
Origin of the word cron?
Trying to settle a friendly argument. Is "cron" an acronym for something?
Additionally, did it's current canonical name "cron" originate from something shortened for something like chronos or ...
4
votes
2answers
618 views
cifs write errors in cron job
EDIT: THE SOLUTION
With Tim's help I determined that larger writes of data were failing versus smaller ones. Why they didn't fail when I ran the script interactively, I don't know...But here was the ...
6
votes
4answers
3k views
Run a script via cron every other week
I've done quite a bit of research in how to do this, and I see there's no direct way in cron to run a job, say, every other Thursday.
Right now, I'm leaning toward making a script that will just run ...
5
votes
2answers
574 views
Open emacs in a terminal when editing crontab
I have setup emacs as my default editor in /etc/profile. When I want to use emacs in a terminal. I open it with the -nw option. How can I have the same behavior when doing a crontab -e preventing it ...
5
votes
2answers
777 views
Automatic security updates on Debian squeeze server
For a production Debian squeeze server, what are the best practices or recommendations for handling security updates? I have seen various articles on cron-apt, apticron, unattended-updates, apt cron ...
5
votes
1answer
568 views
Running cron script with lynx fails to work
I'm trying to automate a login process that can only be done through a browser. I am using the lynx browser to script the actions required to do this. Lynx does this by dumping a user's keystrokes ...
8
votes
1answer
1k views
How can I execute `date` inside of a cron tab job?
I want to create a log file for a cron script that has the current hour in the log file name. This is the command I tried to use:
0 * * * * echo hello >> ~/cron-logs/hourly/test`date "+%d"`.log
...
2
votes
2answers
1k views
List currently running cron tab and stop it
I created a cronjob, it runs for a very long time but now don't know how to stop it. Please help.
5
votes
1answer
565 views
Meaning of “* */1 * * *” cron entry?
Somehow, I am finding it difficult to understand tweaking around * parameters with cron.
I wanted a job to run every hour and I used the below setting:
* */1 * * *
But it does not seem to do the ...
3
votes
2answers
1k views
How can I know when a cron job was killed or it crashed?
Usually when a cron job crash, it will leave some error messages in the log.
We run shell script and some java program with cron job. Recently we found some weird thing out from the log. Obviously ...
4
votes
3answers
4k views
Cron running job every 15 seconds
Could you advise me what to write in crontab so that it runs some job (for testing I will use /usr/bin/chromium-browser) every 15 seconds?
0
votes
2answers
581 views
Sending cron output to email?
I'm trying to send cron output to an email address and am struggling... I'm running the following command:
13 15 * * 1-5 root /path/to/mysql-backup.sh 2>&1 | mail -s "Daily Database Backup ...
1
vote
1answer
90 views
Can I filter how often cron emails me?
I have a few cronjobs and one of them is run every minute. I had to take a website down for two hours and it caused an error on that one specific cronjob and I got almost 120 emails in those two hours ...
4
votes
3answers
474 views
Crontab job not emailing on failure
I have a cron job on Debian:
1 * * * * /home/paradroid/bin/myscript.sh >/dev/null
There is an installed and configured MTA, and I have received emails when the script has a syntax error, so I ...
2
votes
4answers
336 views
Is there any handy command line tool to manage Cron jobs?
Would someone suggest any handy command line (NOT web) tool or script which adds, enables and disables Cron jobs? I am looking, for example, for the following (or similar) behavior:
sh manageCron.sh ...
5
votes
4answers
2k views
Run script in a non interactive shell?
I have a cron job that is running a script. When I run the script via an interactive shell (ssh'ed to bash) it works fine. When the script runs by itself via cron it fails.
My guess is that it is ...
3
votes
2answers
2k views
Can I change the default mail recipient on cron jobs?
I believe that if there is any output from a cronjob it is mailed to the user who the job belongs to. I think you can also add something like MAILTO=vivek@nixcraft.in at the top of the cron file to ...
0
votes
1answer
352 views
grep searchstring /etc/crontab strange behavior in BASH script
I am working on a BASH script which creates automated backups via the crontab. I am trying to use
myVARIABLE=`grep backup /etc/crontab`
to return lines containing "backup" if an entry has already ...
6
votes
1answer
1k views
List of modified files of the past 24 hours
Is there a reliable way to have a system that mails me the list of files that were modified in the past 24 hours inside a set of directories? (like /home/*/public_html/* and /home/*/*domains/*)
3
votes
1answer
810 views
How do I enable locate and queue the database to be built?
On a new Ubuntu 10.4 instance, I tried to use the locate command only to receive the error
locate: can not stat () `/var/lib/mlocate/mlocate.db': No such file or directory
from using this command ...
2
votes
1answer
63 views
App which can execute arbitrary code on different events
I've been looking for a simple activator which can execute some code when stuff happens, I haven't found anything yet. Maybe, I am not using the right keywords. It would be great if someone pointed me ...
12
votes
3answers
2k views
Are multiple @daily crontab entries processed in order, serially?
I want two jobs to run sometime every day, serially, in exactly the order I specify. Will this crontab reliably do what I want?
@daily job1
@daily job2
I'm assuming they run one after the other, ...
2
votes
3answers
1k views
/etc/crontab what does “test -x” stand for
In my /etc/crontab file I have:
# m h dom mon dow user command
17 * * * * root cd / && run-parts --report /etc/cron.hourly
25 6 * * * root test -x /usr/sbin/anacron || ( cd / ...
1
vote
1answer
236 views
Crontab not triggered
I have a program written in C with OpenCV. It captures an image from the webcam and saves on the disk with the name given as an argument. I want to trigger it every minute, thus I inserted the ...
3
votes
2answers
1k views
How to access X display from a cron job when using gdm3? [duplicate]
Possible Duplicate:
Open a window on a remote X display (why “Cannot open display”)?
I'm trying to run a cron job that needs access to my X session. I know my X session will ...
4
votes
2answers
199 views
cron every X exact meaning
In cron you can specify */n where n means every n times period, for instance in the first column is minute.
*/5 means every 5 minutes, but which minutes? 0, 5, 10, ...?
What happens if the number ...
3
votes
1answer
307 views
Using rsync + cron to sync a machine behind a firewall with my dropbox
I have a machine (A) behind a firewall with no access to the Internet, on this machine I can NFS mount directories on another machine (B) which can access internet, and is accessible from Internet, ...
0
votes
2answers
1k views
Running Python script via cron with sudo?
Im using Linux Mint.
I have written a python script that is designed to not be accessible to the logged in standard user but is still be executed while they are logged in. It is to run and log them ...
1
vote
3answers
352 views
Why does Crontab give me an error with my PHP script when running it from the terminal does not?
I'm having some problems with running the Crontab with PHP files.
I have this same php scripts running in the Crontab for more than 6 months but some days ago mysteriously they stopped to execute the ...
2
votes
1answer
468 views
crontab “0/15” minutes + “11-15” hour field: when does that end?
Given a crontab expression like "0 0/15 11-15 ? * MON-FRI", how is that parsed?
I am correct in assuming the 11-15 does not mean "between 11 and 15" but "when the hour is 11-15, inclusive" - i.e. ...
1
vote
1answer
1k views
How to remove obsoleted logs with logrotate?
I wanted to remove unnecessary logs automatically , like Xorg.log.0 , and other packed *.gz files , i really don't need that on a laptop system.
However , i checked man logrotate , but only an entry ...
1
vote
1answer
234 views
vixie-cron.x86_64 doesn't seem to execute jobs on crontab
I have installed crontab on CentOS 5.6 x64 via
yum install vixie-cron.x86_64
Here is my crontab -e
SHELL=/bin/sh
0 0 * * * cat /root/mysql-backup.txt | xargs ...
3
votes
2answers
345 views
How to start the cron daemon
I am using RHEL 5.4
I killed the cron daemon accidentally. I wanted to stop a cron task, didn't know how to do it, ended up killing the cron daemon itself. How do I start it again?
4
votes
2answers
2k views
How to run a cronjob in my regular environment?
Both the shell and environment variables that cronjobs are run in is completely different from the ones presented to me in gnome-terminal. How can I run a cronjob under the same circumstances as if I ...
6
votes
2answers
10k views
How can get a list of all scheduled cron jobs on my machine?
My sysadmin has set up a bunch of cron jobs on my machine. I'd like to know exactly what is scheduled for what time. How can I get that list?
1
vote
1answer
114 views
Need to find a cronjob
I have a problem, some user ,and I'm not sure who, on one of my servers wrote a cronjob that executes every night at midnight. The cronjob creates a sql dump of a database which is then grabbed by ...
2
votes
2answers
765 views
How can I use cron to display messages on the screen via notify-send
I am toying around with notify-send and cron (on an Arch machine) and I can't figure out a way to combine them:
I tried the solution given here and here, but neither worked. How can I use them?
...
0
votes
1answer
104 views
Is there a way to combine a file with crontab?
I'm trying to create an interface that will show a message on the screen every set time. Cron is an ideal tool for this case only it doesn't read data from a file during it's run (as far as I could ...
3
votes
3answers
447 views
Is crontab multithread?
I don't know where I can find more information about crontab, so I ask here.
Crontab is it multithread? How does it work?
1
vote
1answer
2k views
Cron job not executing
I'm trying to use cron for the first time, and I'm stuck.
I'm using Ubuntu 10.10, and the following is my /etc/crontab file. The only modification that I've made is appending the last line.
I've ...
3
votes
1answer
509 views
How to use cron + python to regularly adjust screen brightness?
I want to use cron and this script (http://askubuntu.com/questions/23593/use-webcam-to-sense-lighting-condition-and-adjust-screen-brightness):
import opencv
import opencv.highgui
import time
import ...
1
vote
1answer
351 views
Scheduled task on reboot
How can I schedule a task to run on next reboot?
I understand that we have tools like cron and at to help with scheduling. But they seem to allow scheduling at a specific time and not on specific ...
0
votes
3answers
601 views
How to use gnome-session-save from cron?
I am trying to issue the gnome-session-save --kill command via crontab. I used the command sudo crontab -e. In the file is this:
PATH=/usr/bin
00 00 * * * gnome-session-save --kill
The command does ...
2
votes
1answer
194 views
Cron & Gnu Screen - Trouble with detached screen [duplicate]
Possible Duplicate:
sending text input to a detached screen
I have a script for my Minecraft server that runs automatically every 15 minutes. The problem is that after a server reboot, ...
8
votes
6answers
706 views
CronJob every 25 minutes
I want to know whether there is any easier way to run a job every 25 minutes. In cronjob, if you specify the minute parameter as */25, it'll run only on 25th and 50th minute of every hour
2
votes
1answer
423 views
Check for process already running in webfaction?
I use Django framework on webfaction and have 5 different cron jobs. One of them lasts much longer than others and sometimes gets stuck (30-120 seconds or more).
I have already set that cron job to ...
2
votes
3answers
1k views
linux cron: want to backup a folder
Hello I would like to backup a folder using cron on a centos. The folder c2duo_mms is located in /usr/local/src/djcode/c2duo_mms. I would like it backed ip every 1:00pm on Tuedays to my home folder ...
