Cron is used to execute scheduled commands. It acts as a task scheduler on Linux and UNIX systems which will execute commands at specified times set by the user. Cron has a great deal of customization and is often used on server environments where common tasks are run on a regular basis.

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Cron Script Length

I have a backup script, a script that cyncs file with other files on my computer, and a script that uploads files to my website with ncftp. I used cron to load .sh files, and my shorter scripts work, ...
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Using a NAS as a collective dump, with symlinks for whoever uploaded each file

I have a local machine that was sitting around & doing very little, so I decided to turn it into a NAS (Network Attached Storage) machine, with a 40GB disk for Ubuntu (13.10), a 160GB disk that's ...
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659 views

how do I use upstart, instead of cron, to start a single instance of a job which should always respawn?

How do I script the following bitcoin/dogecoin/etc cpuminer command: /home/digger/cpuminer/minerd -o stratum+tcp://doge.pool.webxass.de:3333 -O <user>.<worker>:<worker_password> ...
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cron error: bad username

I've basically re-written the terminal output instead of appending a series of edits to this question: root@doge:/etc/cron.d# root@doge:/etc/cron.d# tail /var/log/syslog Dec 21 11:35:01 doge cron[...
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386 views

task scheduler in system settings does not appear

i install KDE's Task Scheduler to be able to access to crontab via GUI . After install , i try to open this soft , however , i cannot find where it is. I follow this DEMO on Youtube , and i note ...
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226 views

Need To Rotate Logs From Virtual Hosts on Ubuntu VPS

I have a 1gb VPS running ubuntu that I have installed Apache, Mysql and PHP. I have 3 sites all in my home directory that are using name based virtual hosting. I have created three separate files ...
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871 views

Rtcwake based script not working as cronjob

I'm trying to use the following wake script, which I found here, to put my computer to sleep at night and wake it in the morning. The script uses rtcwake: #!/bin/bash # Auto suspend and wake-up ...
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1k views

Mysterious Ubuntu restart (with logs)

My Ubuntu 13.10 was running a simulation that should last for days, but it for some reason rebooted automatically. The log said: Dec 17 10:24:26 phz225 cron[1078]: (CRON) INFO (Running @reboot jobs) ...
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How to add the logs to a crontab with time stamp

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 > /home/groupz/db-backup/fbackup....
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How to do svn update without password on crontab

I'm new to svn and ssh. I'm trying to do svn update of 5 repositories in my local system every 3 hours on crontab. So, to achieve this I have setup ssh passwordless login using the below steps: 1. ssh-...
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951 views

What happens to cron jobs when the system is down?

As the title suggests: What happens to con jobs scheduled for a time when the system is down for any reasons as server maintenance or whatever? If it is simply not executed: Is there a way to ...
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In a cronjob copy files and change their names to unique values

I want to make a cronjob that makes a copy of every file in /var/log, and puts it in /etc/bak. That i do by making an sh file saying cp /var/log/*.* /etc/bak I would like these files not to be ...
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98 views

Restart service minutes after startup

I have a situation where I'm looking to run a service restart a couple minutes after startup. The particulars as to why are as follows, but the essense of my question is basically captured in in that ...
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67 views

crontab formats

I want to run few crontabs at startup and also at regular intervals. I have used the below format - # M H Dom Mon Dow 0 7-21/2 * * * //this will run daily from morning 7:00 to 21:00 clock with ...
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1k views

Cron running job multiple times

Hello I have a cron job that I have setup, everything was working just fine until a couple of minutes ago when my cron job scheduled to only run every five hours started to run several processes every ...
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471 views

Using rsync to mirror folders on NAS

I have an old netbook that I use as a torrent server running utorrent on ubuntu and accessing with the webUI, at the moment I add links through the UI and then manually copy the files over to my NAS. ...
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3k views

How to install changes to /etc/crontab

If I want to add lines to my system's /etc/crontab, what do I have to do to get them to take effect? Background: I'm trying to set up a machine with Ubuntu 13.04 so that it automatically locks/...
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9k views

Running a script everyday using a cronjob

I need the exact code that I would use because I'm not able to figure it out. I use crontab -e to set up a cron job but when I save it, it never works. I'm also just trying to run a file called ...
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3k views

Crontab and sSMTP

My server is Ubuntu 12.04.3 Cron jobs are working fine. I can send emails through command line, either using mail, ssmtp or sendmail. I have set the correct email address on top of the crontab -e ...
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294 views

How to execute a script with Cron

I would like to schedule a simple script to execute when the machine reboots. I have other schedule other commands in crontab using @reboot without any problems, but I can't seem to get my script to ...
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(Xubuntu) How to set the wallpaper using the command line?

I've done a lot of googling but haven't been able to find a solution to my problem. I am a teacher and I'm using Xubuntu on some student computers. I have everything locked down pretty good, but I ...
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164 views

Unable to start Ubuntu. Unknown Job

I'm new to Ubuntu. It asked me to reboot because of updates. Now it doesn't start at all. I've managed to get to GRUB. I went to previous versions, and selected the only one available (3.5.0-23),...
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Crontab Shut down command didn't work

I wanted Crontab shut down the system daily but it didn't do so, did I misspelled something? This is my Crontab file: /etc/crontab: system-wide crontab Unlike any other crontab you don't have to ...
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661 views

Cron job creating empty files in root

My cron job, command looks similar to this: wget -q http://whatever-url/ It is running correctly (every minute). Problem is that it is creating empty php files at my root for every minute it runs. ...
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116 views

Cronjob for specific hours

I need a cronjob with criteria to power on/off a TV on the basis: Mon-Fri, power on the screen at 07.00 and power off the screen 17.00. Friday after 17.00 to Monday morning to be powered off. I'm ...
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How to create a script to check for internet connection?

I'm new to programming in linux. I started bitcoin mining using linux mint xfce 15. I'm really good following directions, just don't know how to start. I need to create a script that can run every 15 ...
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Why won't cron run my sh script?

Used gnome-schedule to create a script to set my headset as the fallback audio device because it keeps unsetting it when the headset gets disconnected or pc goes into sleep mode. Anyway, crontab is ...
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60 views

problem with crontab entry with time tag

Does the following entry in a crontab have any problem. It's not giving output with time tag.. SHELL=/bin/bash PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/ferret/bin ...
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1k views

Please install an MTA on this system if you want to use sendmail!

I get this message in /var/log/apache2/error.log everytime a cronjob on my desktop wgets a php page that tries to send an email. How can I install a dummy so this message is gone? I already have ...
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724 views

Cron Job Not running after proper setup

So I created a cron job as shown below: GNU nano 2.2.6 File: /tmp/crontab.uNoEXy/crontab # Edit this file to introduce tasks to be run by cron. # # Each task to run has to be ...
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Crontab commands and backup

I have the following crontab running on my server: 0 23 * * * /etc/webmin/postgresql/backup.pl --all @daily /etc/webmin/fsdump/backup.pl 155931323799484 30 20 * * 0 /etc/webmin/fsdump/backup.pl ...
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Cron won't execute if am not logged in

I have a cron that makes a backup of MySql, if I execute on shell it works pretty well even if I'm logged when cron supposed to execute works fine, but if I'm not logged just won't execute, I don't ...
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3k views

Cron is running but not providing output data

I'm trying to make my Amazon EC2 instances stop and start by a crontab. EC2 Api tools is succesfully installed. Manually it works. The cron (which I put in with the command crontab -e): 10 * * * * ...
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288 views

Can I set up a cron job on Ubuntu Phone

I've been looking around, and can't find if Ubuntu Touch can run cron. So my question is: Can it? Also does it have a standard set of bash utils installed?
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Cron not running scripts, no errors in /var/log/syslog

I have a script that creates a file in cron.d and puts some jobs in it. Cron seems to not execute these jobs at all, since the program it runs is set to log all executions. The file inside cron.d ...
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32 views

A bit of help with cron script please

I would like to set a cron on an ubuntu server to download a file to a specific location. How would I go about this? For example once a day I would like my ubuntu server to look for a file on a ...
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Why my weekly anacron job is not executed?

I'd like to use anacron for a weekly job on Ubuntu 13.04. Here's my /etc/crontab: # /etc/crontab: system-wide crontab # Unlike any other crontab you don't have to run the `crontab' # command to ...
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486 views

Script won't run properly in crontab, no path or permission problems

I use the geany text editor, which has a command line option to list all open documents. The following command works fine when run from the command line: /usr/bin/geany --list-documents > /home/...
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Cron job as specific user not running [duplicate]

On my Ubuntu box I have a crontab setup for my normal user that has the following: 0 0 * * * sudo mysqldump -u root -h localhost --all-databases | gzip > /home/<user>/mysqlbackups/db_`date +%...
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536 views

Cronjob is not running, but works from scheduler

I have this script for file show.sh #!/bin/sh zenity --warning --text "here" in crontab i have this line * * * * * /home/user/Public/show.sh then i restarted my crontab user@user-170:~/Public$ ...
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175 views

Schedule task to close

I want to schedule transmission to close at a certain time every day in Gnome Schedule task. I figured out how to get transmission it open at 12:01am, but how do I make it close at 5:00am?
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189 views

Cronjob Bash not exporting

I have written the following script to run for when users have last logged in. I am trying to export a cronjob to a .out file. For some reason, I cannot get it to export. #!/bin/bash for User in $(...
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455 views

Why does my cron job appear to do nothing?

I wrote a groovy script to check a service and send email if it found a problem. It works fine from the command line. I've struggled with getting it to work properly from cron. This is my current (...
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How to set a cron job to run a shell script?

I had set a cron job: 20 * * * * /usr/bin/sh /home/lucky/myfile.sh The main problem is that at the schedule time, there is an error: "mail have sent to /var/spool/mail/lucky". The contents of ...
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290 views

Cronjobs made via cronjob not working

I have the following in my cronjob -e: 00 17 * * 1-5 /home/jhvisser/bin/drive-at-five-record 00 18 * * 1-5 pkill rtmpdump 50 15 * * 1-5 /home/jhvisser/bin/z1035-no-commercial 55 16 * * 1-5 pkill ...
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I cannot find my schedule for system shut down

Long time ago I set a schedule for shutting down the system at a particular time. Now I need to change this time but I cannot find this schedule anywhere. I checked crontab and gnome-schedule Does ...
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3k views

Programmatically sync dropbox without daemon running

I would like to 'manually' force dropbox to sync at certain times (eg at regular, daily intervals using cron, as part of a larger backup script). My goal is to substitute the dropbox daemon with ...
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2k views

Make the daily log rotate run on exact time

I have Ubuntu 12.04.2 LTS server. My daily log rotations which are listed under /etc/logrotate.d/ are executed at the morning around 7:00 am, but it is not on exact time, each day it changed on range ...
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Why can't I restart cron daemon in 12.04 LTS?

I just changed the timezone on my server and therefore need to restart crond so that it will pickup the change, but when I try, this is what happens: root@s2:/# service cron restart stop: Unknown job:...
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6k views

Cron to send email if file doesn't exist

I have a cron job that executes a shell script like following 00 01 * * * sh /backup/script.sh Now I need to add a functionality in cron so that if this script doesn't exist then it generates an ...