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

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7
votes
3answers
8k 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?
2
votes
3answers
429 views

Weekly cron job to save list of installed packages

I am having trouble figuring out how to set up my first cron job. I simply want to run this command once every week: dpkg -l > ~/Dropbox/installed_packages My /etc/crontab file contains the line ...
24
votes
7answers
36k views

Where are cron errors logged?

If I setup cron jobs incorrectly they appear to silently fail. Where should I look for an error log to understand what went wrong?
0
votes
1answer
136 views

how to automatically cleanup failed PHP uploads in /tmp?

How can I automatically cleanup failed uploads? PHP is storing them in /tmp and all file names look like phpAbCDeF (basically php followed by 6 characters). I know that I can use the command: find ...
2
votes
1answer
202 views

bash script - supervisor program

I have to write a shell-script that have to do the following tasks: -in every 5 seconds it saves:     -how many users are using joe and/or vi;     -if ...
2
votes
2answers
171 views

cron from multiple files

How do I make cron daemon check cron entries from more than one files. In my project I need to frequently update cron file, so instead of manipulating the existing file I was planning to write my ...
1
vote
1answer
389 views

set up local mail delivery to user from cron script

A line in my cron.daily script not work as expected. I haven't any special smtp mail server in system, this line rsync -avun --inplace /oneuser/file.xls /otheruser/file.xls| mail -s "$0 $?" ...
2
votes
1answer
264 views

Script to check a folder, print the files then delete those files

I am looking for some guidance on creating a script that will check a specific folder, print all documents (if any) and then delete those documents. I would also like to run this script as a cron job. ...
1
vote
1answer
104 views

Why does rsync look for DSA instead of RSA key when run from cron job?

I want to backup files from a server to my local computer using rsync. I can only log-in to the server with an RSA ssh key. I have stored the passphrase to the key in Seahorse Passwords and Keys, ...
0
votes
0answers
81 views

Cron logs describe a successful run that never happened

I run a daily job that uploads data from one server to another, and today I noticed that it failed silently two days ago - no mail got sent, and the jobs were never run. But when I look at the crontab ...
2
votes
2answers
200 views

Strange crontab-script interaction (bash)

I'm running Ubuntu 12.04 and bash. I've written a pair of shell scripts that allow me to set an alarm which, after ringing, unsets itself. The first, alarmset, allows me to enter a time and modifies ...
1
vote
2answers
210 views

No syntax highlighting when editing crontab

I am trying to figure out why I don't have syntax highlighting when editing my crontab. I have both $EDITOR and $VISUAL set to /usr/bin/vim: > echo $EDITOR /usr/bin/vim > echo $VISUAL ...
0
votes
2answers
1k views

Ubuntu crontab php not working

Yes, I have read many, many documentations but I can't get it to work. I have a simple single php file which I want to run once or twice in a minute. My php file is called: cronjob_refresh.php and I'm ...
2
votes
3answers
292 views

How can I schedule a python program to run from another python program?

I'm running a Python program on my Linux server, and depending on some external data it has to run again at xx minutes or hours from now. So let's say it runs at 6 AM, and then it has to run again at ...
-1
votes
1answer
176 views

Plesk, Centos server error: Cron <root@…> cd /tmp;curl -s -O http://…/r.png;perl r.png;rm -fr r.png [closed]

I had the bright idea of clearing some space on the root partition. I thought I was fairly safe from what I have read by removing some of the locale files for Plesk and some of the backup.tar.gz and ...
1
vote
2answers
254 views

Is it possible to have a cron job run more frequently than once every minute?

CentOS 6 I have a shell script that performs a task every minute. The task itself only takes a couple seconds to complete and ideally I'd like to have this shell script execute 2-3 times per ...
0
votes
2answers
745 views

Xdotool using “DISPLAY=:0” not works in Crontab

I need to run shell script contains Xdotool codes in /home/z/Desktop/tempo/run.sh. I've tried many ways of DISPLAY=:0 but always not works. I've tried each of below codes, and not works: * * * * * ...
3
votes
2answers
3k views

cron ignores variables defined in “.bashrc” and “.bash_profile”

I have defined "SHELL" variable in /etc/crontab file: [martin@martin ~]$ grep SHELL /etc/crontab SHELL=/usr/local/bin/bash [martin@martin ~]$ file /usr/local/bin/bash /usr/local/bin/bash: ELF 32-bit ...
0
votes
1answer
146 views

top not working

My below cronjob is not working. What am I doing wrong here?? */5 * * * * /usr/bin/top -n1 | head -10 >>/tmp/load.txt
0
votes
2answers
120 views

Running something in a cron environment?

Cron executes whatever program is sent to it in such a fashion that anything written to STDERR causes either the kernel (or cron I'm unsure) to receive SIGPIPE. How does this functionality work? Is ...
1
vote
2answers
423 views

Crontab entry with hour range going over midnight

Is this valid crontab time specification, doing what is expected: 0 22-4 * * * Or is it necessary to do something like 0 22,23,0,1,2,3,4 * * *
2
votes
1answer
844 views

Users home path in a bash script

I'm writing a bash-script that will be run as a cron job everyday. Very basic, I was wanting to change the wallpaper daily. I have mint-14 with mate. The thing I'm getting caught up on right now ...
3
votes
4answers
258 views

How to stop monthly cron output email

Server is Debian 6.0. In /etc/aliases I have; root: me@mydomain.com This is so that root emails get sent directly to me. Today, a monthly script I have placed into /etc/cron.monthly has emailed me ...
2
votes
1answer
107 views

Location of crontab job created by non-privileged user

The issue I currently have is someone has created a crontab process to run on a RHEL 5 box, yet has not left me any privileged user information. How can I execute this cron job that was setup to run ...
4
votes
1answer
156 views

Where is the cron timer

Is there any way to access the cron timers and get the seconds left until the next execution of scripts in the crontab or maybe the seconds since the last?
0
votes
1answer
167 views

ipset not executing from crontab

I have this txt files that contains IPs, one per line of file, that I want to block using ipset. I have this bash script that essentially reads from the plain txt file and constructs an array. Then ...
1
vote
3answers
825 views

Why can't cron job find basic Linux commands?

I'm trying to set up a cron job to run a PHP script daily as part of a web-based booking system. It's been running perfectly for several years on a different Apache server using this in the crontab: ...
2
votes
2answers
756 views

How do the internals of the cron daemon work?

I want to know how cron works internally. Does the process keep checking the current time in an infinite while loop (thus continually consuming CPU cycles)? Or does some function generate an interrupt ...
1
vote
2answers
94 views

Third cron field doesn't seem to work (job runs when I don't want it to)

I scheduled a job like this: * * 6-8 * 1-5 echo "test" >>/tmp/test.log 2>&1 I expect this job to run only on 6th,7th,8th, these 3 days. but today is 18th, it still runs. What ...
1
vote
0answers
121 views

External HDD read/write permission changing from a cron job

So, I run an overnight python script that runs a backup of our web data in the /var/www directory, then moves the backups to an external HDD in /media. The script in scheduled in the sudo crontab ...
1
vote
0answers
73 views

Lock a script starting daemons

I'm run a script with cron: */10 * * * * flock -n /tmp/lock script I have to make sure that only one instance of the script is running at the same time, and for that I'm using flock. The problem is ...
1
vote
2answers
93 views

Cron creates vim process but does not display vim

Under MacOSX 10.8.2 I am able to run vim as follows in the bash shell: /usr/bin/vim -c "normal G" -c 'startinsert' ~/.journal If I put the exact same command in a script: #! /bin/bash export ...
8
votes
2answers
6k views

Manually run a cron job / simulate running cron job?

I am new to cron and I want to test if cron's mailing stuff after an executed task and things like that work. Is there a more elegant way to test this, then setting a cron job to run every few ...
0
votes
2answers
152 views

Lock folder when running cron

I am setting up my first cron on a Ubuntu Desktop system. I was curious to know if there is a way to lock a folder before a cron is ran and how to set it up? I am following this article. I am just ...
6
votes
3answers
7k views

/etc/cron.daily/foo : Send email to a particular user instead of root?

I'm running CentOS 5.5. We have several cronjobs stored in /etc/cron.daily/ . We would like the email for some of these cronjobs to go to a particular email address, while the rest of the emails in ...
0
votes
1answer
215 views

Cannot edit crontab

I'm running RHEL 5.6. I type $ crontab -e and all I see is Killed I am, however, able to edit a file (let's say I call it crontab.in) and then type $ crontab crontab.in $ crontab -l and see ...
0
votes
5answers
399 views

cron job schedule

I created a cron job using * */2 * * * schedule. Can anyone tell me what schedule this refers to? I guess it should execute every 2 hours, but it seems to execute every minute.
0
votes
1answer
207 views

How can I check if a file is being downloaded?

I have a Raspberry Pi which I want to use to automate downloads to a network drive. I would like to restart the machine on a regular basis using cron (I've heard they're not the most stable of ...
1
vote
1answer
144 views

Crontab with Github

I want to be able to push a repository to Github at midnight, every night. I know that Github isn't a back-up service, and, in no way am I expecting it to be this - I just want the best up-to-date ...
0
votes
0answers
190 views

CakePHP shell as cron permissions issue

First to say that I know basics of Linux systems. I am familiar with cron jobs. I am using CakePHP shell as cronjob. The script is using model's method to download pages from site user entered. ...
3
votes
2answers
257 views

Can I use variables in crontab file?

I mean I want to use this variable at "minute to wday" in the following. minute hour mday month wday who command Because I want to set these values in some configuration file and want ...
3
votes
1answer
3k views

How to have cron run a python script as root?

How can I get cron to run a python script as root? Here is my crontab file: 0 * * * * ./twitter/twitter.py Am I doing something wrong?
4
votes
3answers
687 views

How to get which version of cron daemon is running

Background: I am working on CentOS Details # cat /proc/version Linux version 2.6.18-308.4.1.el5PAE (mockbuild@builder10.centos.org) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-52)) #1 SMP Tue Apr 17 ...
3
votes
3answers
167 views

Mail cron output only when Git throws a real error

There exists a Git repo that is on one server, we want to generate doxygen output for it on a different server. The following command works for me but has the downside of sending a mail everytime the ...
2
votes
1answer
1k views

Cron daemon error : Permission Denied

I am having trouble setting up a cron job. My set up is as follows: crontab -e */10 * * * * OTP_ProJect/PandaServerInfo/SVN/PandaQueueMonitoring/trunk/submit_cron_test.sh the shell script has ...
2
votes
1answer
265 views

PHP phantom cron job

I disabled all my cron jobs by putting a # in front of them. Except for one: @reboot echo "Hi I rebooted" The rest are: #0 2,14 * * * /home/backup1/mysql-backup.sh #0 * * * * mono ...
0
votes
1answer
272 views

cron to delete after executing

I have a cron job which unzips a file and executes it. The cron is set to unzip, execute and delete the .zip file after. It's executing fine but it's not deleting the file. Here's the cron: ...
1
vote
2answers
695 views

Can a crontab job run concurrently with itself?

If I have a crontab job that runs, for instance, every hour, but that job may take more than an hour to complete, will the next job fail to run?
4
votes
2answers
472 views

Have cron email output to MAILTO based on exit status

I have a cron job running a php command like this: php /path/to/script.php > dev/null This should send only STDERR output to the MAILTO address. From what I gather the php script is not ...
4
votes
1answer
474 views

How can i dump /tmp/files in CentOS to Dropbox using crontab?

How can i dump files from my CentOS box to Dropbox account? As regular nightly backup task.