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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Any reason why Ubuntu's man page on crontab(5) is less informative?

Why is the man page for crontab(5) at manpages.ubuntu.com less informative than corresponding man page at linux.die.net? Compare The "sixth" field (the rest of the line) specifies the command to ...
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175 views

What does this mean in “crontab -e”?

When I run crontab -e, I see this bit: Notice that tasks will be started based on the cron's system daemon's notion of time and timezones. How to convert the cron's system daemon's notion of ...
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816 views

Script not running in crontab, file not found

I need your help to run a bash script in crontab. As many other posts in askubuntu I'm facing the problem that a script that is properly running in terminal mode does not run in crontab. The error I ...
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133 views

Deja-dup cannot access Truecrypt volume when run from Cron

I have a deja-dup set up to backup into a mounted Truecrypt volume. It works fine but now I would like to run deja-dup in my own intervals via Cron (set up for my account): * * * * * env DISPLAY=:0 ...
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13k views

Cannot run cron job for a php script

I want to run a php script using cron job on localhost my script is situated at - /opt/lampp/htdocs/rrugd/myscript.php now as opt is under root, i tried adding the cron job for root as well as ...
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unattended-upgrades not running, /etc/cron.daily/apt missing

I have automatic-upgrades installed and configured, but it never seems to run, because there are always security updates waiting to be installed when I check. ...
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1answer
966 views

Ubuntu VPS Automatic Backup Script

Can anyone tell me how to create a backup script for Ubuntu VPS which is used as a webserver. I also want to add it as a cron job so that it runs automatically every day midnight at ...
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9k views

Create a Screen session with a bash script using contab

I want a .jar file to run every time the server boots up (we're using a VPS), and so I've edited crontab using crontab -e and then adding @reboot bash /home/bash/startserver.sh. But I haven't even ...
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62 views

Scheduled Power On/Off of 2nd HDD

im using a ubuntu 13.10 Server. I want to switch off the 2nd HDD completely and only power it up once a week to back up the system+data from the 1st HDD. I know how to use crontab, but I dont know how ...
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4k views

php script not executed by crontab

I have setup a cron to execute one of my php scripts. But the problem is the php script is not being executed at all not even partially. Here is the cron I have set up 45 23 * * * /usr/bin/php -q ...
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60 views

Crontab wont run a script

I've set a script to run every 10 minutes using cron, but it does not run. It works when I run it manually. bin path is /usr/bin/. The script contains: #!/bin/bash scrot 'screenshot.png' -e 'mv $f ...
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239 views

Start-up / Reboot scripts for different users

I'm still trying to learn a little more about bash scripting and start-up / reboot, I have read about crontab @reboot and also just looking at other options but I just wondered if someone could maybe ...
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62 views

# in crontab used for what?

If I add up the # in front of some crontab task then it won't work and behave as comment ? right ? I want to disable some task for sometime until I like to enable. # * * * * /home/user/xx Thanks ...
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303 views

Ubuntu Server cron job doesn't work

My script that is supposed to run only when the server is on isn't working correctly when run by cron. If I run it manually, it works. backup() { if pidof java &> /dev/null; then ...
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1answer
72 views

Check when folder was last synchronized with rsync

I'm using a cron job to backup a folder to another computer. I'm not sure whether or not it succeeded and /var/log/rsync.log is only showing errors, all of which occured before the scheduled backup. ...
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675 views

How to craft a crontable entry that keeps MongoDB running in the event of a crash?

I need help crafting a crontable entry that will make sure the MongoDB service (daemon) is running on a particular port and if it is not, start it. I want to set this up so that if MongoDB crashes, ...
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2answers
345 views

screen shot from command line

I am writing a sh file to take screen short and want to schedule in crontab but when i run the .sh file it run OK no problem happens but when try to schedule it in crontab i got an error like ...
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11k views

Can symlinks be used in /etc/cron.d/?

I'm trying to implement a configuration mechanism that allows in a certain project to deploy through svn a cron configuration. I immediately thougt that what I should do is cerate symlinks from ...
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1k views

How can I get mysqldump to use the credentials from mysql_config_editor in a crontab-executed script?

I am setting up a daily backup of a MySQL 5.6.14 database using mysqldump on an Ubuntu 12.04 Precise server. I created the credentials file in the root home directory (.mylogin.cnf) according to the ...
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3answers
5k views

(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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1answer
6k views

How to detect error in cron jobs

The reasons why a cron job may fail is really very large. Most common reasons may be, Syntax error Using executable without proper path Using a shell variable which is not defined in cron ...
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Make CronTab not asking for id_rsa keyword when running in terminal

I like to do some git pull inside a script and see see output of it. So I made up this cronjob to test: DISPLAY=:0 * * * * * mike /usr/bin/gnome-terminal -x zsh -c "/var/www/up.sh; zsh" ...
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2answers
45 views

How to put availabe disk space into filename?

I have a SFTP user only and I want it to be able to see available space. I want to make a cron that runs each 30 minutes, to delete the old file and put the new file to show free disk space. I could ...
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6k views

Running PHP Cron Job with Arguments

Im trying to run a PHP script, once a day, on ubuntu 13.10 server with php5. I have cron jobs set up, via ajenti control panel, verified with crontab -l, for this command. php /path/script.php ...
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4k views

Automating duplicity backups using cron

How do I automate duplicity backups using cron using gpg encryption and the ssh backend?
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129 views

Why the cron job did not fire on ubuntu 12.04?

Here is the script sqlite_backup.sh under $HOME/: #! /bin/bash now=$(date +%d) echo "Welcome to Sqlite backup script" sqlite3 /var/www/db/nbhydb.sqlite3 << EOF .timeout 20000 .backup ...
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493 views

Why do I get that error from a CRON job?

I am trying to write a cron script to check if my minecraft server is running or not and if it is down to run the start up script. Here is what I have and this is the error I get when running it ...
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4answers
114 views

Is it possible to limit Software Center or apt-get install downloading to a specific time of day?

I have free bandwidth everyday from 12 am till 7 am. That means I put everything that I want to download in the software center and go to sleep. I want the download process to stop at 7 am. For that ...
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2answers
55 views

Network Information for Theft Prevention [closed]

I haven't seen much of this around, and I'm not a network expert/sysadmin, so I need some advice. I have a laptop that I'd like to "protect" against theft (this is really a game more than a real ...
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1answer
961 views

System crontab entries not being run

I am running Ubuntu 12.04 LTS Desktop. I have used the /etc/crontab to set up a couple of entries that should run at different schedules. Now, the problem is that these do not seem to be running. I ...
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60 views

Folder Action for Ubuntu [duplicate]

I have a question concerning Ubuntu folder action , I need a script to notify me when a file is add to a folder or the folder changes , is there any possibility for that. I found some articles ...
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1answer
272 views

Running Key Remap Script at Startup

I'm trying to re-map my left Alt key to the Alt Gr and Alt Gr to Left Alt. So far I've been able to do it in terminal, but it never runs it on start up. I've read multiple AskUbuntu questions, but ...
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92 views

Only part of crontab working [duplicate]

i have a line in crontab: * * * * * date >> /home/pana/temperatures.txt; hddtemp /dev/sda >> /home/pana/temperatures.txt ;hddtemp /dev/sdb >> /home/pana/temperatures.txt ;sensors ...
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1answer
114 views

cron not outputting correctly?

Please forgive my ignorance. I have searched, but perhaps I’m not sure really what to search for in order to answer my question myself, so I’m turning to this forum for a little guidance. I’ve ...
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1answer
170 views

Where to check if a cron job was ever run?

I set a few cron jobs locally on my machine. They were supposed to run each night at 8 PM. Where can I see or check that they actually run?
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294 views

Auto shut down if usage timer exceeds daily limit

I would like to activate a cron job valid for specific users only (for my kids) that it will check if the kids use the pc more than e.g. 60 min per day and then poweroff system. This means that if the ...
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2answers
2k views

Setting cron to run a shell script: random wallpaper from a webpage

I have written a shell script which downloads random wallpaper from a web-page and sets it as a background every 5 hours. Here is the script: #!/bin/bash countervar=1; finish=0; cd ...
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1answer
98 views

Crontab script entry not working

beginner here. I have a script called updateTf2.sh It's contents #!/bin/bash /etc/init.d/srcds stop ./steamcmd/sh +login anonymous +force_install_dir ./tf2 +app_update 232250 +quit ...
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87k views

How to run a cron job using the sudo command

Is it possible to run a cron job which needs the sudo command? Like: sudo rm somefile
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556 views

Can't get crontab to repeat command every five minutes

I'm trying to make crontab run a sh script every 5 minutes. This is my root (sudo crontab -e) crontab setup: */5 * * * * /etc/test.sh and this is the script: #!/bin/bash echo "time:$(date)" ...
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2answers
1k views

Including application crons

I have 5 web applications. The directory structure is similar to following: /var `- /www `- /domains `- /domain1 `- ...
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3answers
37k views

Cron Job Not Running?

I have a crontab file that looks like this: * * * * * /home/abliskovs/update/update.sh However when I check the syslog for evidence that the job has run, there is nothing that might indicate that it ...
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1answer
359 views

crontab entry to reboot than email

I got my weekly crontab reboot entry to work using /sbin/shutdown -r but now I want it to email me when the reboot happens. Ideally I would like the email to happen after it rebooted so I know the ...
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2answers
2k 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 ...
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111 views

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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32k views

How to restart every 30 minutes automatically?

I would like to schedule a restart of my Ubuntu every 30 minutes. Is there any command or a graphical way to do it?
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987 views

Telnet output file DOES NOT WORK Correctly UNDER Crontab

I'm using the Ubuntu 10.04.4LTS, and have Ganglia installed in my computer. I used to get the Gmetad data by typing: telnet localhost 8651 > /test/test.txt or made a .sh file to run it. After ...
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2answers
632 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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8k views

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 ...