Cron is a job scheduler that allows users to run commands periodically.

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Are the crontabs of users linked?

Our Linux server has a community user that has a crontab for itself. The admins don't want me to schedule my scripts on their crontab because they don't want to take responsibility for my programming. ...
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1answer
18 views

crontab nodification is taking too much time

There are 300 processes configured in a single Linux server's crontab. if I want to stop or modify any of them, I have to comment them out (i.e. # ..cron..) for all processes. It's a time consuming ...
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2answers
2k views

crontab's @reboot only works for root?

man 5 crontab is pretty clear on how to use crontab to run a script on boot: These special time specification "nicknames" are supported, which replace the 5 initial time and date fields, and ...
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1answer
237 views

What does /etc/cron.daily/apt do?

Could someone explain what the apt script is doing in cron.daily please? I can't find any documentation on it. NOTE: I'm trying to investigate a server-server communications issue which frequently ...
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6answers
34k views

Why did my crontab not trigger?

I used crontab -e to add the following line to my crontab: * * * * * echo hi >> /home/myusername/test Yet, I don't see that the test file is written to. Is this a permission problem, or is ...
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1answer
66 views

Execution behaviour of cron

I want to schedule a cron so as to avoid running at midnight. I was thinking a period of 7 minutes. Now, I figured out with 7 minutes of interval, the last cron schedule for a particular day would be ...
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2answers
135 views

Script from cron doesn't create archive

I'm using: # cat /etc/redhat-release CentOS release 6.4 (Final) Have an script in user's crontab: $ crontab -l 0 7 * * * /home/teamcity/scripts/TC_backup.sh If I run this script under this very ...
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42 views

Create a fake read only device like file with incrond

I need to generate UUID with uuidgen (not through any function call, but external command, because processes which will read the file cannot call any APIs or external commands directly). My idea is ...
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20 views

Run Xdotool on multiple users at once

When running Xdotool on user one (cron): * * * * * export DISPLAY=:0 && xdotool mousemove 10 10 and I switch to user two for several hours, and back to user one, I find out Xdotool not ...
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1answer
914 views

running a script every 30 minutes with crontab using ROOT (Debian)

When I manually type: root@username:~# ./myscript.sh the script executes, however I tried the following combinations to have crontab execute myscript.sh every 30 minutes (forever) and none seem to ...
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1answer
669 views

What causes cron to continuously send mail and how can I disable it?

I have a problem on CentOS 6.3 system where the crond process tries to unsuccessfully send mail over and over (at least I think this is what its doing) until the OS eventually generates a "too many ...
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1answer
684 views

“stdin: is not a tty” mails for running scripts as cron jobs

I have several shell scripts (bash) which are started by cron. Every time a script is executed I get an email saying "stdin: is not a tty". Can someone please tell me how to fix this? All scripts run ...
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29 views

Unplug AC causes anacron to stop. No resumumption if cron.daily had already started?

Anacron is started/stopped by a number of means, one of which is when AC power is plugged/unplugged, as can be seen by examining /etc/apm/event.d/anacron and /usr/lib/pm-utils/power.d/anacron. You can ...
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1answer
143 views

Rotating iptables logs, strange message about script being converted to upstart job

I use a script /etc/logrotate.d/iptables containing entries like: /var/log/in_iptables.log { rotate 4 weekly missingok notifempty compress ...
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2answers
2k views

Globally change path for all users, even in cron

We're setting up an SGE cluster with CentOS 6. My sysadmin is installing applications that are not installed via RPM (i.e. via other means like make install) should go in a non-standard directory, in ...
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1answer
178 views

Crontab change MAILTO for only one specific job in Root's crontab

Can I do the following to change where mail goes for one specific crontab job in root's crontab (don't sent to root for Do Something job, just send to porklover): # Make a hambone appear * * * * * ...
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34 views

How do I interpret an entry about cron in Gnome System Log Viewer

Apologies if this turns out to be a trivial question. I am trying to set up a regular backup of my files prior to installing Fedora 19 instead of my current Fedora 12. In November 2013 I started a ...
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1answer
65 views

Does cron impose some limitations to types of commands and privilege of execution? [duplicate]

I've experienced an issue where some of my scripts run perfectly fine when I call them manually, but these same scripts when called as cron jobs via cron don't seem to work at all. So my question: ...
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7answers
4k views

How to restart the Python script automatically if it is killed or dies

I am running my Python script in the background in my Ubuntu machine (12.04) like this - nohup python testing.py > test.out & Now, it might be possible that at some stage my above Python ...
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1answer
119 views

Running cron jobs under php ver. 5.4

My hosting company switched me to php version 5.4. I run a Drupal site (D7.) They say: You'll want to make sure your crons use "/usr/php/54/usr/bin/php" instead, as otherwise it will use PHP 5.2. ...
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1answer
390 views

How to check whether my cron job for backup using tar was succesfull [closed]

I have a cron job to tar backup websites and databases and upload the backup to a NAS. Instead of checking the tar files on the NAS. Is there any way to check if the tar backup process completed ...
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3answers
134 views

Disable cronjob after reboots

How can I prevent cronjobs from automatically starting after my server has rebooted? Every time I reboot my server the cronjobs start up again, which I'd like to prevent. These servers are running ...
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3answers
4k views

Day of week {0-7} in crontab has 8 options, but we have only 7 days in a week

Day-of-week: Allowed range 0 – 7. Sunday is either 0 or 7. I found this after Googling, my question is why should both values (0,7) correspond to Sunday?
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1answer
88 views

How to switch tty with a script / cronjob

Is it possible to switch the current tty/vt with the help of a bash script or a cronjob? I only know the physical keyboard input "Ctrl-Alt-Fx". I would like to show two virtual desktops at different ...
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1answer
176 views

Is this sar/sysstat cron job formatted correctly?

I want it to give me all the sar/sadc options, interrupts,disk,etc.. every 10 seconds starting at noon for the entire hour. On the second line I want to capture the info in /proc/interrupts every ...
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2answers
608 views

Need help with a script to test for memory usage

I'm trying to put up a temporary band-aid while I work out a solution for a app's memory leak. What I wrote was a small bash script that I put in the root on the server. This is what the script is ...
2
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1answer
87 views

Cron does not execute xinit command

I have a command that works perfectly when launched from the prompt: xinit /home/user/myscript.sh -- /usr/bin/Xvfb :1 -screen 0 1x1x8 But is not executed when put in crontab: @reboot xinit ...
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6answers
558 views

How to Find a Fugitive Crontab

A few years ago I setup a cron job to automatically ping a URL every minute as part of a monitoring system (that's oversimplification, but it'll do for this question). Because I'm a horrible person, I ...
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1answer
337 views

How to restore default crontab file

I have recently lost my cronjobs. now when i do crontab -e i am presented with an empty file. i would like to get the default file back with the nifty comments and explanaitions at the top!
2
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1answer
206 views

Suddenly lost all cronjobs

All of a sudden my cron jobs don't work any more. When I type crontab -e I am presented an empty file in the editor /tmp/crontab.3fMYGi/crontab And by empty I mean that not even this standard ...
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3answers
448 views

Is setting a higher nice level for a process an effective way to reduce its impact on system load/CPU time?

I have an rsync cron job which is pushing the server load and triggering monitor alerts. If I set the job to be run with a high nice level, would that effectively reduce the impact it has on system ...
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2answers
223 views

How to add the logs to a crontab with time stamp [duplicate]

In crontab, I scheduled a daily backup script. Now when the cron executes the script the status are logged to a log file as shown below. 0 0 * * * /home/backup.sh > ...
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2answers
196 views

Bash if script is called from terminal echo stdout to terminal, if from cron do not echo output

I would like to have a service watchdog script echo the status to the screen if called like ./watchdog.sh but if it is run by cron, there is no need to echo output. What is the proper method? Where ...
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1answer
137 views

Mysterious automated emails

I remember messing around with crontab and setting up email capabilities on a server many months back, and now all of a sudden I'm getting the following email: EMAIL HEADER: from: root ...
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3answers
58 views

Where to put system cronjobs?

If I need a cronjob that runs at system level (i.e. not specific for a certain user) how do you suggest me to create it? running crontab -e as root appending it to /etc/crontab creating a file ...
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1answer
435 views

Create cron as a apache user and run as root user

I am creating this cron as apache user and want to run this cron as root, below is my code snippet: # Create a cron job to restart apache cron_file="/etc/cron.d/restart_apache_crontab" cron_job="*/1 ...
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4answers
5k views

Cronjob for rebooting everyday

I have set this cronjob because I want my server to be rebooted everyday at 05:00 # file: /etc/cron.d/reboot * 5 * * * root reboot &> /dev/null I think it worked the first time as I was ...
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1answer
80 views

Why don't these cron jobs run?

Here is my crontab: # rsnapshot jobs 0 9-21 * * * /usr/bin/rsnapshot -c /home/kaiyin/.rsnapshot.conf hourly 52 22 * * * /usr/bin/rsnapshot -c /home/kaiyin/.rsnapshot.conf daily 42 22 ...
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2answers
174 views

Shell script passing null value while executed as cron job [closed]

We are using the below commands to get pagesapce values and I need to check percent of used pagespace. For this I have used the below code, but when running this script it's passing a null value into ...
0
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1answer
114 views

Why does OpenSSL automatically send me Terminal mail?

I for some reason am getting messages from OpenSSL constantly (not literally constantly, but every hour or so) sent to my Terminal mail box saying: Message 1: Subject: Cron ...
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0answers
46 views

CronTab on OpenShift

I have a robot witch updates a particular page on Wikipedia every 2 hours. I copied it to OpenShift and made a Crontab on my own computer witch connects to OpenShift via ssh and run the robot. How can ...
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1answer
172 views

How to rebuild /etc/cron.d on CentOS?

I installed an RPM on a CentOS machine that was supposed to merge its own files contained in a /etc/cron.d structure with the current /etc/cron.d. However it replaced the current contents. I believe ...
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3answers
5k views

How do I completely silence a cronjob to /dev/null/?

On my Ubuntu-Desktop and on my debian-server I have a script which needs to be executed each minute (a script that calls the minute-tic of my space online browsergame). The problem is that on ...
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1answer
62 views

Mailing output of cron

I have this script which I run once a month, and I want to get the output sent to my email. If I run it manually like so, then the standard output is sent to my email. ./monthly_mail.sh | mail -s ...
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1answer
3k views

How to use Crontab for a java file in linux

How can I use Crontab in Linux specifically for a Java program? I want to run a MIS Script. How can I crontab it and what should the path be?
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4answers
208 views

Does cron jobs per se represent a significant burden on a modern system?

I'd like to run a pretty simple script (is there a dir with name x in dir y if so move it to dir z–and x will only be there about once a day) every 15 seconds or so (one minute divided into 4*15 ...
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3answers
68 views

Command to run an application within a specific directory

I want to be able to type a line of command to do the following two commands that I know: cd ~/rpitwit_commands/ rpitwit This is because I want to automatically run it upon boot in crontab, and it ...
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1answer
88 views

How to run a script as soon as the week number changes?

I would like to keep my download folder sorted. My goal is to have the files of the current week in the download folder, and the older files in a folder named after week number and year (eg 2013.09, ...
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1answer
803 views

Pimp rsyslogd to have less i/o (cron, pam,…) and less logging

On my raspberry I really don't need crons and pam logging and I want to have less i/o to make the SD card life a little longer.. I have already removed cron with the second line cron.none, I'm ...
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1answer
231 views

How to respawn vpnc when it stops?

As root, I've setup a crontab rule that launches vpnc everyday early in the morning (before I arrive at my workplace). But it often occurs that the vpn stopped mid day. As a result, I have to sudo ...