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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How to tell cron to find paths to tools?

Is there a way to indicate to cron how/where to find (paths to) tools such as python, nmap, php and so on? I ask this because when I schedule a job using crontab -e, I always need to specify the ...
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1answer
96 views

cron does not work

I read about cron. I edited it by running crontab -e and I added this line: * * * * * php /var/www/createFile.phpWhen I run ls /tmp/ I do not see any file create by my php script. Why does not it work ...
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1answer
107 views

How to schedule an irregular backup script requiring user confirmation

I have a backup script which requires user interaction. I would like to schedule it to run, say, once a week. The constraints are that (1) the computer boots straight into Gnome and is turned off ...
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261 views

Which tasks in “Scheduled Tasks” (gnome-schedule) use anacron versus cron?

I am trying to run a command once a day, but my machine is not always on. anacron says it's meant for such purposes, but I prefer to use the Gnome Scheduled Tasks GUI program. If I schedule a task to ...
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531 views

Start a transmission-gtk using a cron job

I'm trying to start my torrent client using a cron job. Following is the job I added to crontab file(contab -e) 00 20 17 07 * transmission-gtk I waited for the time but transmission-gtk didn't ...
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99 views

Crontab Instances

I have been doing some research on scheduling tasks and what not. I came across the crontab command function. Is crontab a file that is created or is it a command? If it is a file, then how many can ...
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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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3answers
4k views

Who is sm-msp-queue and how does he/she/it flood my /var/log/syslog?

I run Linux BeagleBoard-xM 3.12.5-armv7-x10 #1 SMP Fri Dec 13 03:06:20 UTC 2013 armv7l armv7l armv7l GNU/Linux and my /var/log/syslog gets flooded by messages like Jan 11 10:21:09 BeagleBoard-xM sm-...
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2k views

What does this (root) CMD line in system.log mean? Why is it there?

What does it mean? (root) CMD ( [ -x /usr/lib/php5/maxlifetime ] && [ -d /var/lib/php5 ] && find /var/lib/php5/ -depth -mindepth 1 -maxdepth 1 -type f -cmin +$(/usr/lib/php5/...
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739 views

sending email from cron with correct format

I am stuck when sending email in correct format from cron jobs executing my php script which fetches records from mysql database. i have a php script which fetches records from database and renders ...
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1answer
3k views

Run the script file after 5 or 10 min after restarting the system

I have created a ruby script file that checks the connection present or not. For example checking port 22 is opened or not. Firstly I tried with cron job as follows @reboot find ${HOME}/my_app/...
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81 views

Error starting python file using cron

I'm trying to get a python file to run every 2 mins, I'm using the following cron command but the script never runs. Would anyone know what the possible errors could be related to starting a python ...
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2answers
3k views

Cron not working

Wrote a short shell script "wallch.sh" to randomly change my desktop background: DIR="/home/user/Wallpapers" PIC=$(ls $DIR/*.jpg | shuf -n1) FIL="file://" gsettings set org.gnome.desktop.background ...
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96 views

Crontab not run job and change job

I've set 'Crontab' with root user and -e key but Cron is not running my jobs and after little time, my job is removed and replaced with other text!!!! The jobs set: # m h dom mon dow command @...
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1answer
2k views

Why is my cron script to dump a MySQL database not executed?

I have the following cron job: * * * * * /home/db_backups/test.sh which runs fine and is executed every minute. If I check with sudo grep \(CRON\) /var/log/syslog I get the following: Jun 23 11:30:...
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2answers
265 views

crontab with espeak doesn't work when sound card is busy with google hangouts

There may not be a solution to this, but here's the problem nonetheless :) I'm on Ubuntu 14.04, using latest Chrome as my browser My sound card is busy being used by Google Hangouts My crontab is ...
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3answers
1k views

Cleaning up yesterday's files via script

I would like to run a cronjob that ran every morning to move the files that were created on the previous day in a specific directory to be moved to a folder that has been created with the previous ...
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287 views

update from 12.04 to 14.04, cron stops working

I am having trouble of using cron after updating from 12.04 to 14.04. here is my log: May 8 11:00:01 imanqasrina CRON[30716]: (sicksand) CMD (bash $HOME/bingwallpaper/bingPaper_v1-0.sh) May 8 11:...
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142 views

Understanding the at-command to schedule another command

I use cron to schedule things in Linux, but recently I discovered the "at" command. sudo apt-get install at I don't understand the scope from which this command operates: How would you schedule a ...
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2answers
6k views

sendmail with cron job

a=$(df -h /mnt/smb | tail -n +3 | tr -s ' ' | tr '%' ' ' | cut -d ' ' -f 5) echo $a if [[ $a -ge 30 ]]; then cat /etc/diskspace/text.txt | sendmail test.gmail.com fi Hallo guys this is my ...
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206 views

Does duplicity detect when a Backup Is Already In-Progress?

Any time you schedule a recurring backup, it is always possible for a previously-initiated-backup to run so long that the next scheduled backup gets initiated before the previous backup completes. ...
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22 views

Start Skype on boot with crontab [duplicate]

I includes these entries yet Skype don't manage to start on boot: @reboot /usr/bin/./skype @reboot /usr/bin/skype
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1answer
280 views

difference between atjobs & atspool directory

when i was working with ubuntu 12.04 at command i noticed that there are two different directories /var/spool/cron/atspool and /var/spool/cron/atjobs . I want to know what is the difference between ...
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662 views

Cron job running successfully suddenly reports script is not found

What might cause cron to suddenly report a file it is supposed to run is "not found," when the file hasn't been touched, and in fact, the entire system hasn't been touched since it last ran ...
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365 views

Cron doesn't execute one of the scheduled jobs

I'm using a lubuntu desktop, distribution Ubuntu 13.10, i686. This is my problem: in the job list scheduled by cron a job hasn't effect, but in /var/log/syslog its execution is traced. This is the ...
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1answer
850 views

Bash script runs fine, but not in cron

I have a script that's supposed to record a shoutcast stream for an hour, convert it to mp3, and then save it. The script runs correctly when I run it from the terminal, but I can't seem to get it to ...
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1answer
479 views

Running a Screen instance of a program as non-root

I've got a dedicated server (Ubuntu 12.04, no GUI) set up to launch an instance of McMyAdmin and attach it to a screen instance every time I reboot the hardware. I have the command saved to root's ...
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2answers
399 views

cronjob output will not show in terminal

I've been trying to get the output of a cronjob to show in the terminal and I can't figure it out. Every minute I would like to run the script /usr/games/sl and have it output in the terminal, and I'...
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2answers
822 views

Running shellscript with cronjob is making problems, executing manually not. Ideas?

I made a shell script called /home/root/cron_grads.sh (chmodded 755) on my server. In this directory are more grads-scripts like 500hPa_p0.gs (644). My main script creates a temporary file grads_exec....
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1answer
186 views

backup without overwriting old backups

I'm using Ubuntu server 14.04 to backup all data from '/mnt/test/ folder' to '/home/john/' with TAR and archive to stuff.tar.gz and to make it to backup automatical. I use cron to backup it every ...
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263 views

Stopped Jobs error upon logout

There are times when I attempt to logout of SSH and I get something along the lines of: There are stopped jobs Not knowing what this is, I end up force quitting putty with the exit button in the ...
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2answers
1k views

Cannot run a GUI app from cron

After doing a "sudo su -" on an Ubuntu 12.04 notebook I did a "crontab -e", added this: * * * * * env DISPLAY=:0.0 /usr/bin/gnome-calculator and waited for minutes. Nothing Happened. I don't have ...
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108 views

syslog time is not matching cron string setup

I am running many cronjobs in my server. When I was checking the syslog file to see the cron timing, it's completely not matching. Can someone help me to understand. syslog May 23 00:00:01 xxxxxx ...
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227 views

Tiger: `rtm` is listening on socket XXXX

On my Ubuntu serve 12.04 LTS, Tiger is reporting a lot of stuffs like this: OLD: --WARN-- [lin002i] The process `rtm' is listening on socket 60404 (UDP) on every interface. NEW: --WARN-- [lin002i] ...
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1answer
486 views

How to execute livestreamer command with cron?

So the other day I installed Ubuntu 14.04 LTS at home in a partition next to Windows 7. As I'm not able to be at home to watch the Sailplane Grand Prix live as streamed on YouTube, I decided to use ...
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1answer
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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2answers
1k views

How to schedule a command to run a few seconds after startup?

I was trying to use @reboot /my/script in cron to run a script on a 10.04.4 VM running in VMware Fusion top print ifconfig to a file on a shared directory, which is /mnt/hgfs/somedir. It didn't work ...
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1answer
2k views

Curl request from cron job is not working,but works manually

I have a cron job that runs every minute and makes a curl request and i have verified that using grep on the syslogs. But the curl is not happening somehow and moreover i have a small echo statement ...
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41 views

Keep backing up (copying) the same file to a new folder

I am saving a stream in my HDD. I'd like to copy the file periodically into a subfolder backup such that the older versions of the the file are not deleted. Simply put Assume the original file is ...
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439 views

Allow user to run programs as root without password. Would it be the correct solution to my problem?

I have a server which I need to be running certain programs permanently; I'm having problems with two of them and I'm not sure if the solution I've found would be the correct one, so I ask for opinion ...
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2answers
597 views

cron job not executing youtube-dl command

I want to use the "youtube-dl" command in a cron job to download videos fron youtube. Therefore I created the following cron job: 26 00 * * * /usr/local/bin/youtube-dl -o '/home/ubuntu/youtube/%(...
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2answers
384 views

Why this script doesn't work in cron and generates a empty output?

Why this script doesn't work in the cron for root or other user and generates a empty output ? /tmp/test-1.log --------------- #!/bin/sh /bin/echo this is test-1.sh /bin/date "+%FT%T" Permissions ...
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1answer
692 views

Simplest MTA mail setup for a desktop to receive (ana)cron emails

Ubuntu (12.04 LTS) doesn't seem to install any sort of mailer by default. Everybody seems to recommend installing Postfix. I am familiar with Postfix, which I use on several "real" servers. But it ...
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5answers
3k views

crontab not running as root

Mysql backup scripts not running as root crontab - help I'm trying to run a crontab as root but the script is not running successfully. I can see in syslog that the script is executing but it does ...
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2answers
276 views

Intermittent crontab problem

My crontab entry intermittently fails to find scripts in my user's home directory. The crontab entries run exactly on schedule as specified, and occasionally the script runs correctly, but mostly it ...
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1answer
392 views

How to get a timestamp on rsync output

I have an hourly crontab job @hourly rsync -avc --delete /DirA/ /DirB/ > /home/job.txt However when I check the logbook I see no timestamps. How can I get timestamps in the log so that I can be ...
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1answer
135 views

Execute script when disk space is low

Is there a smart way to execute a script when disk space is low? I know I can manually check disk space, but it seems like a common problem to want to delete log files when disk space is low (for ...
3
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1answer
988 views

How we can copy one file from one server to other in cron

Can anybody let me know how we can copy a file from one server to another in a cron. I know about scp but how we use it in a cron, since we need to pass the password. Edited I found this link Expect ...
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1answer
61 views

Command to find how much data was transferred from USB

How can I create a cron job that runs every minute and logs how much data was transferred by USB? Ideally I want log of amount the data in bytes transfers done. For example if i tranferred 4mb file ...
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3answers
1k views

mplayer can't play audio from cron while ncmpcpp is playing simultaneously

I have set up a script, which executes an mplayer command, in order to play audio in crontab. It will be executed in a special set time, but this script can not play audio when ncmpcpp (a front-end ...