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

learn more… | top users | synonyms (1)

4
votes
1answer
255 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. ...
1
vote
1answer
102 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 ...
0
votes
1answer
97 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 ...
0
votes
3answers
311 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 ...
4
votes
1answer
1k views

Automatically detect when a file has reached a size limit

I would like to send an email when a file reach a certain size limit. The only way I thought of doing this is by doing a cronjob which will check the file size and send the email if the file is ...
1
vote
1answer
44 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
votes
2answers
160 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 ...
2
votes
1answer
359 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
votes
1answer
45 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 ...
5
votes
2answers
301 views

How can I peek at the output of a running crontab task on OpenBSD?

I have an hourly hour-long crontab task running with some mtr (traceroute) output every 10 minutes (that is going to go for over an hour prior to it being emailed back to me), and I want to see the ...
15
votes
7answers
631 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 ...
1
vote
1answer
77 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 ...
0
votes
1answer
85 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 ...
1
vote
2answers
6k views

sh script will not execute as root (cron)

I have the following script added to cron. If I add touch thisisatest.file to the first line it will create a file named thisisatest.file, but not execute the rest of the code. If I manually type ...
14
votes
6answers
13k 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 ...
1
vote
2answers
677 views

Cannot edit crontab as non root user

When I use the command crontab -e on my Debian server as a non root user (in this case as postgres), I can't edit it because of "/tmp/crontab.SJlY0Y/crontab" [Permission Denied] crontab -l on the ...
0
votes
0answers
15 views

Shell script to monitor log files going over a certain size [duplicate]

Due to another issue I'm tracking down, one of my app servers occasionally starts generating a large amount of errors and then becomes unresponsive. For now, the simple solution is to restart the ...
0
votes
1answer
106 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 * * * *?
2
votes
0answers
55 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
votes
2answers
171 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 ...
0
votes
1answer
906 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 ...
1
vote
0answers
67 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 ...
0
votes
0answers
132 views

Configure cron for daily NMon task

I want to configure a cron job for NMon to gather stats during all day, everyday. Leaving a file per day to dump into NMon Analyser. I know the proper command to get a spreadsheet format its ...
0
votes
1answer
46 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 ...
0
votes
2answers
534 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 ...
0
votes
1answer
316 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'; ...
1
vote
3answers
50 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 ...
1
vote
0answers
181 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 ...
2
votes
1answer
149 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"] ...
11
votes
1answer
12k views

Why does cron silently fail to run sudo stuff in my script?

I have a script run from a non-privileged users' crontab that invokes some commands using sudo. Except it doesn't. The script runs fine but the sudo'ed commands silently fail. The script runs ...
0
votes
1answer
41 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 ...
26
votes
8answers
44k views

How can I run a cron command with existing environmental variables?

How can I run a cron command with existing environmental variables? If I am at a shell prompt I can type echo $ORACLE_HOME and get a path. This is one of my environmental variables that gets set in ...
1
vote
2answers
399 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 ...
2
votes
3answers
3k 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 ...
30
votes
1answer
1k views

Why aren't crontabs stored in user home directories?

I'm curious to know: why are crontabs stored in /var rather than in the user's home directories? It makes it a total pain to isolate these files for upgrades but I suspect that there is a logical ...
1
vote
1answer
36 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 ...
1
vote
2answers
96 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 ...
1
vote
1answer
50 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
vote
1answer
75 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: * * * * * (. ...
5
votes
3answers
1k views

Cron to not run on specific day but all other days

I have a cron setup to execute a bash script daily at 10pm. I have another cron setup to run monthly on the 1st of the month. Both crons launch a bash script, and the only different in the bash script ...
0
votes
2answers
3k views

How can I check if my cronjob is runnning on my server via PHP?

I would like to give out a warning If cron is not running or if a certain cronjob is not set in crontab on my server. Is this possible to check with php?
0
votes
1answer
155 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 ...
2
votes
2answers
394 views

How to make my bash script be able to create an log file for a clamscan running in cron?

I've created an custom clamscan(clamav) in bash and when I run it in my shell everyhing is fine, but if I run it in a cron, it can't create the log file. This are the errors: ...
0
votes
1answer
36 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" ] ...
2
votes
3answers
2k 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 $?" ...
0
votes
1answer
8k 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?
0
votes
1answer
354 views

openSuse, not running the cron job

I have created a cron job in the /etc/cron.d/dispatchingEmail_I the permissions of dispatchingEmail_I are the following: -rw-r--r-- 1 root root 84 Sep 11 19:52 dispatchingEmail_I content of ...
1
vote
3answers
902 views

Using nohup to keep a script running indefinitely

I am very new to Linux and I've only been using it to SSH to my web server using Putty. The issue I am having is this: Basically I've got 2 php scripts. One get_tweets.php constantly listens for ...
0
votes
1answer
269 views

Unable to install crontab on OpenSuse

I am running the following command as root, on OpenSuse: linux-gn77-PC:/home/harbir/project # crontab -e when the editor opens up I type the following, as I want the command to be run at 2145 hours ...
1
vote
1answer
107 views

Execute All Cronjobs in ~/.zshenv Environment

I want to execute all cronjobs in the environment defined in my ~/.zshenv, and I want to redirect STDOUT and STDERR of every cronjob to a single log file. I am on OS X 10.9. What is the cleanest way ...