cron is a task scheduler based on clock time that runs on Linux-based machines.

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2answers
123 views

SSH: Dismiss read mail messages from Cron

Whenever I ssh to my server box, I get 'You have mail' along with banner message. Then I type mail, and go through msgs, by hitting enter, until At EOF shows up, and when I do quit or ctrl+d, and ...
2
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1answer
357 views

Schedule a cronjob everytime it is done

I have a cronjon which runs every 48 hours. But ideally what I want is that it must start running as soon as it stops. Can this be done? It is an sh script consisting of a python command. I am using ...
2
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1answer
1k views

Make shell script commands to abort after certain timeout

I have often a situation in Linux shell scripts that if a specific command takes too long to run e.g. due to a network problem the shell script should abort running this command. What best practices ...
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2answers
2k views

crontab -e fails to start

whenever I try to run crontab -e I'm getting errors such as: no crontab for banana - using an empty one /tmp/crontab.oeFm1e: Invalid argument Is there any way to edit / install the file?
2
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1answer
801 views

Schedule bash script for one time use on OSX

I'm trying to do a little script that, as a function, will take a file and date as input and delete that file on the specified date. So I only need it to schedule to run once, and that's it. I'm on ...
2
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2answers
4k views

Cron environment variables

I'm running a simple shell script that runs just fine in a login shell from cron, where it doesn't run. For some reason, /usr/local/bin is not on the users path when run from cron while it is when run ...
2
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1answer
7k views

Crontab script on Mac OS X Lion does not work anymore

I have a problem with cron tasks. Previously this script worked fine on Mac OS X 10.6 server, but when I initialize it on Lion (client), this script stopped working. Basically, this .bat file calls ...
2
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2answers
849 views

wget doesn't see proxy under cron

I'm new to freebsd and have a problem: my script uses wget. when I call it from the command line it works fine and I see the output like this: --2011-09-22 15:55:58-- ...
2
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2answers
2k views

How to set CRON to execute a php file outside of a public html folder?

I have a php file located at, let's say, for example: /data/web/process.php This file is not publicly available (no virtual host is running in that folder, but apache is installed). I need to ...
2
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6answers
5k views

How to change wallpaper from command line in KDE 4.3?

Basically question is in title, but let's elaborate a bit: I have KDE 4.3 from Arch Linux. And a script which periodically downloads new wallpaper. So I'd like to set it as current wallpaper from ...
2
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0answers
43 views

Setting up a watchfolder

I want to make a folder that I can put any video file into and have ffmpeg catch it and spit it out as an mp4 and remove the non-mp4 file. I have the following: for f in *.*; do ffmpeg -i input ...
2
votes
1answer
256 views

Cron Command for twice a month on Sat @12am

I am wondering if someone can help with the simple but sometimes confusing commands regarding Cron jobs. I would like a cron job to run twice a month on a Saturdat @12am.
2
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1answer
115 views

How to make cron perform task every hour during business hours?

I'm trying to make a script run twice every hour during business hours on weekdays, and i have the following in my cron setup: # m h dom mon dow command 8,48 8-17 * ...
2
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0answers
54 views

Performance loss when having too many files in /etc/cron.d?

Is there an amount of files in /etc/cron.d that would lead to worse performance? There are currently about 50 jobs in. In the future there can be up to 200 files in. Am I correct to expect the cron ...
2
votes
3answers
471 views

Is it possible to run two instances of crond each with its separate cron file?

How to run two instances of crond with different cronjob files? Is it even possible?
2
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2answers
194 views

easy way to automatically retrieve image for desktop background?

I would like to automatically download and replace an image from the NASA website to use as my desktop. in linux i used a cron job to do this, using wget to retrieve the file and a small utility to ...
2
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0answers
811 views

Set the from address on emails from cron/Set default from address for sendmail

As a normal user I can send email, either from the commandline or from PHP. But when a cron job has error output, sending of that email fails (I have a MAILTO=me@example.com at the top of the ...
2
votes
1answer
227 views

cron job not executing

I have a cron job that is supposed to run a script every 15 minutes. */15 * * * * /path/to/script.sh I checked in three hours later and found that the script never ran, even once. Earlier I tried ...
2
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2answers
1k views

What are the limitations of crontab?

Hardware considerations aside, are there any limitations on: The maximum number of cron jobs that can be scheduled for a single user The maximum number of CONCURRENT jobs that can be scheduled for a ...
2
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1answer
1k views

/etc/environment and cron

I've got two machines: Fedora and CentOS. And a cronjob 0-59 * * * * env > /home/me/env.log On CentOS I can see that /etc/environment is affecting the output while on Fedora it does not. I want ...
1
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2answers
228 views

Who's the cron worker?

If I set cron job for a normal user instead of root, what account execute the scheduled jobs?
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2answers
7k views

crontab - /bin/sh: wget: command not found

I want to set up a crontab on my Macbook Pro running Lion. I run the usual crontab -e and provide a quick job to see if everything is working ok --- */10 * * * * wget -O - -q -t 1 ...
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1answer
580 views

How to set an offset for cron jobs?

I have seven scripts to launch that take quite long to process, so for my first idea, I wrote my crontab like this: 0 */3 0 0 0 /home/personal/my-script-1 0 */3 0 0 0 /home/personal/my-script-2 0 */3 ...
1
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2answers
426 views

Cron to run command once a day, no mather what time

I want to run a cron command only once a day but not at a specific time as the times my computer is on are unpredictable. Can I do it?
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3answers
2k views

run cron every minute during a specific hour?

Running a cron job every minute is easy, running it at specific minutes past the hour is easy. But is it possible to say "only between 1300 and 1400 run every 1 minute"?
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2answers
843 views

Following script doesnt run as cronjob

snailmail.sh #!/bin/bash echo "Test" >> /tmp/out /usr/bin/kdialog --title "MAIL RECIEVED" --msgbox "mail recieved!!" crontab -e #CronJobs located in $HOME/cronjobs/* * * * * * ...
1
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2answers
4k views

Schedule a cron job ev X minutes, but exclude it from certain hours in the morning?

Is it possible to make a cron job run say, every 20 minutes, but make it not run for say, 1-4 in the morning.
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2answers
1k views

os.popen returns empty string when called from cron

I'm trying to get my Raspberry Pi's CPU usage like so: def get_cpu_usage(): return os.popen("top -n1 | awk '/Cpu\(s\):/ {print $2}'").readline().strip() When executed normally, this method ...
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2answers
2k views

kill and restart process by cron

I've got python script running on a remote machine, periodically it stops responding so I ssh in, kill the existing process, and then restart it. I have to do this several times a week and it's ...
1
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2answers
2k views

JAVA main class not found when using Apple auto-ingest tool

I am trying to setup a cronjob to download my daily and weekly reports from iTunes Connect. I have downloaded Apple's Autoingestion.class and I have made the following shell script to download the ...
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4answers
232 views

Cronjob not working

I've got a simple crontab for ripping my local radio station only when I want: 0 16 * * 0 /root/streamripper.sh 0 17 * * 0 killall streamripper 0 20 * * 0 /root/streamripper.sh 0 21 * * 0 killall ...
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3answers
818 views

The 'which' command returns nothing via cron, but works via console

I've written a little utility in haXe + Neko that needs to execute some GIT commands. To avoid hardcoding the path to the GIT executable I'd like to use the which command to find out where it is. ...
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3answers
1k views

What's wrong with my cron job time schedule?

I'm trying to setup cron jobs for a website hosted on hostmonster.com. When I use the following it runs perfectly: * * * * * But whenever I make changes to these timestamps the script doesn't ...
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2answers
40 views

What happens if shutdown command kills my unison cron job?

I have an Arch linux box at home that I power off quite frequently (the power supply is noisy and it annoys my girlfriend...!). The box has a number of cron jobs running the unison utility, designed ...
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2answers
2k views

How to setup muliple cron job every 3 hours but not simultaenously?

I need to run cron jobs during the following times: 1st job: 1PM 4PM 7PM etc.. 2nd job: 1:15PM 4:15PM 7:15PM etc.. 3nd job: 1:30PM 4:30PM 7:30PM etc.. As you can see each job run every 3 hours but ...
1
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1answer
112 views

Why this cronjob wont run

On debian squeeze as user root I add this cronjob with "crontab -e" */1 * * * * root /usr/sbin/ntpdate ptbtime1.ptb.de >> /var/log/ntpdate.log But this cronjob will not run, there is also ...
1
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3answers
3k views

How to run a script at boot time for normal user?

I want to run a bash script at boot time in CentOS 6. I added the script in /etc/init.d/ directory but all these script are run by root. I want to run script for any user.
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1answer
826 views

Difference between 0,10 and */10 for crontab?

I wanted to run a cron every 10 minutes. What's the difference between the syntax 0,10 and */10?
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2answers
551 views

Why cron saves at /root, when should at /var/www?

Why my cron */1 * * * * /usr/bin/php /var/www/query/query.php &> /root/querylog.log saves query.php output in the /root/ folder? (this script shall save *.txt at its location) It should do so ...
1
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2answers
963 views

Writing a cron job to email myself

How would i write a simple cron job to email myself a message at a certain time? Also is it possible to create a cron job without root access. I'm trying to use my school's server?
1
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5answers
7k views

Disable cron jobs for a specific user

I have a list of jobs in the crontabs for user1, user2. I want to prevent the jobs of user2 from running. I tried listing user2 in cron.deny, but that only prevents him from accessing his crontab. ...
1
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2answers
3k views

Open a terminal from a Crontab

How do I get a gnome-terminal window to open from a crontab? I have tried this: * * * * * /usr/bin/gnome-terminal * * * * * source /home/user_name/.bashrc ; /usr/bin/gnome-terminal * ...
1
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2answers
762 views

Cron fails to run bash script

I have bash script #!/bin/sh DTFILE=/etc/daytime.addr DTPORT=13 DAYTIME_ERROR=/tmp/dtm.err function daytime_error(){ if [[ -z $1 ]] then exit 1 fi if [[ -e $DAYTIME_ERROR ]] ...
1
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1answer
48 views

rsnapshot: What's wrong with my crontab?

I am using Rsnapshot for backups (Linux CentOS 6). Here is my /etc/cron.d/rsnapshot: 30 11 * * * root /usr/bin/rsnapshot nowandthen > /backups/rsnapshot_cron.txt 2>&1 15 11 * * 4 root ...
1
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1answer
180 views

scheduling with cronjob to run the php file for only one time

How do I run the php file only once using the cron jobs. i.e., to schedule task to work on 20/06/2015 10:30:00 I tried something like this : 30 10 20 6 ? 2015 /usr/bin/php ...
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vote
1answer
529 views

Using anacron in cronie on Gentoo - Doesn't run?

This is the system crontab on a Gentoo system with cronie installed, with the anacron use flag enabled: 59 * * * * root [ ! -x /etc/cron.hourly/0anacron ] && rm -f ...
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2answers
94 views

Running executable from Crontab

I have a file called Exim_queue_size in the root directory. It contains one line: exim -bpc | mail -s'Exim_queue_size' bert@example.com It has had its permissions set with chmod +x , and is thus ...
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2answers
4k views

Why does root cron job script need 'sudo' to run properly?

I'm running this simple script on my Raspberry Pi to auto update so I can forget about it. It also keeps a log that says whether the update was successful. The script is update.sh: #!/bin/bash echo ...
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2answers
921 views

How to find out the reason why a scheduled task hang?

I have scheduled quite a number of tasks in my Windows 7, doing a variety of cron jobs on my machines. I am perfectly sure that these tasks, when run on their own, won't hang. But the problem is ...
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3answers
677 views

cron table mailx caused empty content

I'm using centos 7.0/6.5. The content of /etc/cron.hourly/mail.cron #!/bin/sh log=/var/log/mail.cron.log echo "`hostname` `date`" >> $log 2>&1 mailx -s "test mail" me@example.com < ...