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

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Changing user's wallpaper via system crontab

I tried to set up wallpaper change via cron in /etc/crontab, but I failed. DISPLAY env set directly / before cmd, but still it's not working: DISPLAY=:0.0 * * * * * ad env DISPLAY=:0.0 /usr/bin/...
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0answers
90 views

How to set one job to run at precise time with anacron without losing config at next upgrade?

I want logrotate to run at a precise time daily. Currently it is set to run at some random time using anacron and I don't want to change the randomness factor for all the other jobs. I have ...
0
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0answers
79 views

How to know the which jobs are scheduled in cron for today

I am looking to get the details of jobs which are scheduled to run from cron for today and need to make it as a script by 12AM every day to get the job details that are scheduled for today and like ...
2
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2answers
267 views

change the name for root mails from cron

I have two servers that are synchronized with rsync, one is the failover server of the other, so they both have the same name. Now root mails that are sent to my other account are all named from root ...
6
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1answer
25k views

How to run a cron job to execute every minute?

I am trying to create a directory having timestamp in its in name in the /home directory. I have created the following cron job as root user. But it's not running. What am I doing wrong? Following is ...
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1answer
208 views

Shell script runs differently when schedulled with cron

I have a strange problem with my backup script. To begin with, this is the backup script: ########################################################### # CODE BEGINS HERE #############################...
2
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1answer
120 views

Remove tar compress spool from cron email

I have a crontab job that call a simple script to backup a website: 15 0 1,10,20 * * /home/username/bin/backup_whatever This is the script: #!/bin/bash TODAY=$(date +"%Y%m%d") FILE_TO_PUT="...
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1answer
71 views

Edited /etc/cron.d/anacron, changes are immediately in effect?

After editing /etc/cron.d/anacron and saving the file, are the changes immediately acknowledged by cron? Or do I need to run a command to tell cron to reload /etc/cron.d/anacron?
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1answer
160 views

Scope of shopt options in cron script

I have a bash script that is run nightly in a cron job. It needs to do case insensitive file matching, so the script calls shopt -s nocaseglob I want to make sure this does not affect other cron ...
3
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1answer
528 views

Cron can't access my home directory when I'm logged out

I have quite a strange problem using cron. I distilled it thus far: I created following simple bash script in /home/user1/cron_dir/cron.sh: #!/bin/bash echo "Success" As user1 I created following ...
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0answers
40 views

start xscreensaver from cron@reboot, ubuntu startup, service/deamon?

I need start xscreensaver for ubuntu, and it can be started in ubuntu startup application. my question is: can xscreensaver be started in cron@reboot? can xscreensaver be started in service/deamon? ...
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1answer
338 views

run btrfs balance with cron

Since I run today in a problem with a full disk, which turns out is not unbalanced. Which you can fix with btrfs balance. So my question is: Is there any risk by ruining this by a cron job? (in ...
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1answer
53 views

Can someone be so kind as to setup a cronjob for me? [closed]

I've been trying to get cron to execute these two scripts to schedule and post on twitter, tumblr, facebook and linkedin. It worked once and never again. <?php require '/opt/bitnami/apps/...
4
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1answer
137 views

high precision subsecond cronjob replacement [duplicate]

I am looking for a cron replacement which could run subsecond schedule, is there have any "still alive" project which serve this purpose? Currently running Ubuntu 14
0
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1answer
399 views

crontab not executing my script?

I added this rule to the bottom of my crontab * * * * * /root/test.sh It basically resets iptables so I can fool around. If I mess up I won't be locked out of my box. When I run the script in bash ...
2
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2answers
329 views

Emulating /etc/cron.d/ on OSX

On most modern unixes, cron supports individual crontab files in /etc/cron.d, in which each task executes as a specified user. These files automatically update the crontab once edited. They allow ...
2
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2answers
3k views

Send backup by email with crontab

I use this cron job to do a backup of /home/blah/ each day at 01:00 a.m. : 0 1 * * * tar -zcf /home/blah/backup.tgz /home/blah/ In fact I would prefer that an email is sent to me with the .tgz file ...
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1answer
443 views

Are there disadvantages/consequences to adding scheduled tasks directly to /etc/crontab instead of using the crontab command? [duplicate]

CentOS 5.x I noticed that someone (presumably another admin) added an entry directly to the bottom of /etc/crontab so it reads like: SHELL=/bin/bash PATH=/sbin:/bin:/usr/sbin:/usr/bin MAILTO=root ...
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1answer
2k views

cronjob does not execute when not logged in

SOLVED, see 'useless' answer. I have a cronjob in my crontab. When I specify the job to be executed in 2minutes, I wait, and then I can see files created by the job, I can see the process with ps. ...
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1answer
307 views

How to restart my server automatically using crontab if they went down?

I have a jar file which I am running like this in my Ubuntu 10.10 and then it starts my exhibitor server in the background - nohup java \ -jar /pekooz/exhibitor-1.5.1/lib/exhibitor-1.5.1-jar-with-...
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1answer
151 views

Cron job — If computer inactive for x minutes turn wifi off

I would like to have an alias command in my .bashrc that could be ran at startup. That states: If computer is inactive for X minutes then turn off wifi. How would I do that? I am currently using ...
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1answer
71 views

Cron Job Not working [closed]

I have been trying to create a cron job to execute a script located in ~/Documents/script.sh at midnight every night and every 8 hours after that. I have found a lot of material on this but for some ...
0
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2answers
399 views

Crontab does not work properly in Ubuntu

I am learning how to use cron. I wrote some simple code in my crontab # m h dom mon dow command */1 * * * * echo "1 minute"> ~/Document/cronoutput I expected it to print the words every ...
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1answer
3k views

How to execute recurring Bash script at specific times?

How would I set a script to execute on every Tuesday and Thursday at 11:50am? I've been looking at the at command, but I can't conceive how to use it the way I need to from its man page.
3
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1answer
58 views

fault-tolerant crond replacement

I'm looking for a replacement to crond, or possibly an extension of it. The feature that I definitely would want to have is fault-tolerance. E.g. if a job failed to run due to the computer not being ...
1
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1answer
223 views

CentOS machine keeps “losing” active directory membership

All of our CentOS 6 machines have been joined to our active directory domain. Each of these machines eventually "loses" their domain membership, which breaks authentication for AD users. I created a ...
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1answer
537 views

Crontab permission problem

I have a fc19 host at work. This morning crontab did not work. $ ls -l /usr/bin/crontab ----------. 1 root root 53472 Jun 11 2013 /usr/bin/crontab The permissions -------- means no one has access ...
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6answers
93k views

What does '>/dev/null 2>&1' mean in this article of crontab basics? [duplicate]

I am reading an article about crontab There is something about disabling automatically sending emails. Disable Email By default cron jobs sends an email to the user account executing the ...
0
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1answer
436 views

What does */13 do in a crontab?

*/n * * * * in a crontab means run every n minutes, if n divides 60 evenly. What happens for other cases, like */13 * * * *?
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0answers
173 views

Configure job to expire

I'm learning Linux at the moment and were doing some exercises scheduling jobs with cron and crontab, but I'm wondering if it's possible to limit the amount of times that the scheduled job is ran. ...
0
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2answers
418 views

Why does this Shell script fail as cron job [closed]

I have the following in a shell script, when I run this script it works but when I put this as a cron job it does not work(nothing happens!). How come? script #!/bin/bash file="/home/nalangi/...
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1answer
203 views

Please help me to debug this notify-send battery alert script

I used crontab -e to define the following: */5 * * * * env DISPLAY=:0 /home/max/.bin/battery-check.sh The contents of the script are: #!/bin/bash ...
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1answer
4k views

Null message body; hope that's ok

I have the following command below as part of a cronjob. When I run the command via cron or at the command line, I get Null message body; hope that's ok. The contents of the email are empty but when ...
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1answer
143 views

How to do version-control repository update in crontab?

I'm trying to automate version-control repository update in crontab. The following script /home/usr/mrbean/bin/update.sh works in interactive Bash command-line: #!/bin/bash ROOTPATH="/home/user/...
0
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1answer
69 views

CRON path problems

I have a Python script that runs from the command line beautifully, but when I try and run it from CRON does strange things. The script generates, then runs an apk script file. The apk script file ...
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1answer
648 views

Cron Log File Outputs Nothing

I get no output from my cronjob. The script the job is executing is: <?php require '/opt/bitnami/apps/wordpress/htdocs/wp-load.php'; include('/opt/bitnami/apps/wordpress/htdocs/wp-content/...
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0answers
471 views

Cron job scheduled to run on specific day-of-week is running on last day of month as well

I have a cron job scheduled to run every Thursday at 6am via the following schedule: 0 6 * * 4 It's been running as expected, but on Tues, September 30th it ran (unexpectedly) and again on Thursday,...
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3answers
74 views

Where is this cronjob running?

We have a news server running on a CentOS 6.5 box. It's leafnode, and a cron is set to run every two minutes. We decide to shut it down to troubleshoot other issues, so we comment out the line in ...
2
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1answer
299 views

To write this Pseudocode with Regex

I am doing a Makefile which I run regularly by Crontab every day at 0230 crontab -e; 30 2 * * * /bin/thePseudocode Python-like Pseudocode directories = ["Cardiology", "Rheumatology", "Surgery"] ...
0
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1answer
133 views

Cron, crontab -e reads the wrong file

I do a simple: crontab -e In the top of this file, I have: #DO NOT EDIT THIS FILE - edit the master and reinstall. And I see that it has opened up some temporary file under /tmp I am using ...
2
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2answers
276 views

Cron job not behaving as expected

So I have a python script that pulls down git/svn/p4 repositories and does some writing to a database. I'm simply trying to automate the running of this script and based from what I see in syslog it ...
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2answers
957 views

cron will find certain commands on the PATH but not others

Having issues making crontab run certain commands, despite the PATH and SHELL being set correctly. Here is the env of the machine: SHELL=/bin/bash USER=ubuntu MAIL=/var/mail/ubuntu PATH=/usr/local/...
3
votes
3answers
6k views

Cron job to check if PHP script is running, if not then run

I am wondering if someone might point me in the right direction. I've got little experience working with the Linux command line and recently due to various factors in work I've been required to gain ...
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1answer
77 views

Need to automate the updating of the crontab file

We have an automated process where a server is built, and after applications/middleware are installed using another automated process, and the crontab needs to be updated for those applications/...
3
votes
2answers
2k views

Do spaces matter in a crontab

It's not clear to be from the manpage for crontab. IS extra white space allowed between the fields? e.g., if I have this: 1 7 * * * /scripts/foo 5 17 * * 6 /script/bar 31 6 * * 0 /scripts/bofh is ...
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0answers
175 views

Maintain screen session when executing shell script on boot

Solved: I solved this problem by introducing a delay before executing the script: @reboot sleep 60; /root/start_server.sh On Ubuntu 14.04, I have a crontab entry set to run on reboot: @reboot /...
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1answer
74 views

High precision scheduler daemon

I'm looking for a scheduler daemon like cron, but with at least seconds precision so I can use it for a radio automation app. I've heard conflicting rumors about cron's ability to handle seconds. If ...
1
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1answer
102 views

Why can I not source a file with the default cron installed on a debian wheezy server? [closed]

I use cron for years now. In order to load all my environment variables at once, I define them in a dedicated file (often but not always .bashrc) that I source in the crontab: * * * * * (. /home/me/...
0
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1answer
471 views

How do I do “Hello World” to try using cron

I am using Fedora 20, and want, eventually, to set up automatic backups. I managed a trial run on my previous Fedora 12 installation, but can't get started again. I am using zshell. I thought I would ...
0
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1answer
65 views

Why is there an apt-get script set in my cron.daily, I'm on Fedora 20?

I found this file tonight: /etc/cron.daily/apt.cron #!/bin/sh [ ! -f /var/lock/subsys/apt ] && exit 0 [ -f /etc/sysconfig/apt ] && . /etc/sysconfig/apt [ $CHECK_ONLY == "yes" ] &...