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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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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1answer
1k views

Why does Ubuntu Server run both cron and atd?

From the man pages it appears both do basically the same thing, why have both running on the system at the same time? From the wording in the man pages it looks like cron will repeatedly run programs ...
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1answer
483 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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1answer
2k views

Cron not sending email notifications

I'm finishing biulding our new server, based on 12.04 32-bit desktop version. I've set up a few cron tasks, that are running as they're supposed. only, I've added the MAILTO = ...
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1answer
474 views

Cronjob not working

I have added a new line to my crontab file, but this line won't work. This is the code of my crontab file: # Music scrobbler # Every 5 minutes */5 * * * * php -f /var/www/Music/scrobble/index.php # ...
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0answers
622 views

Why doesn't duply work when set as a cron job?

I have a problem with a cron job which starts but doesn't complete. Running the command manually works fine. I already read the page about cron issues and solutions here on AskUbuntu, tried the ...
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2answers
955 views

Only run CRON job if connected to specific wifi network

I am a newbie to scripting on Linux (Lubuntu), but I would like to make a script that runs a cron job only if my laptop is connected to my home wifi. Is this possible? I guess, I could do something ...
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3answers
29k views

How can I tell if my hourly cron job has run?

I have created a file called ntpdate in /etc/cron.hourly #!/bin/sh /usr/sbin/ntpdate-debian date > /tmp/william_tmp date > /william_tmp date > ~/william_tmp echo test I also did Chmod 755 ...
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1answer
1k views

What is the story behind the default times set in /etc/crontab?

To my understanding, this is the default configuration of /etc/crontab: # m h dom mon dow user command 17 * * * * root cd / && run-parts --report /etc/cron.hourly 25 6 * * * ...
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1answer
581 views

Why does cron.hourly not care about the existence of anacron?

This question came up over in Root Access. Why does the default /etc/crontab not check for existence (and executable flag) of /usr/sbin/anacron for the hourly entry? My /etc/crontab: # m h dom mon ...
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1answer
930 views

Why isn't this simple CRON job working?

I am on Ubuntu server and would like to send an email to myself every 10 minutes (as a test). The code for that is in this file: /var/www/cron-test.php To set up the cron I typed: crontab -e ...
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801 views

Split a large XML file by a certain node into smaller files

I've got a XML file with 1GB (about 6000000 Lines). The goal is to split this file into smaller .xml files with more or less 20000 lines each. <?xml version="1.0" encoding="UTF-8"?> ...
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3answers
6k views

Deleting a file owned by root

Recently, a friend played a prank on my pc and now I have a file sitting on my desktop called 'hardcore_porn_xxx'. The problem is it does not go away by a simple delete. I'm new to linux so any help ...
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2answers
568 views

Set server timezone but not working with crontab and phpmyadmin

TimeZone is not working properly I am using linode server running ubuntu 12.04LTS. My Question is when i configured timezone by using dpkg reconfigure tz as IST ASIA/Calcutta. It shows correct ...
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1answer
278 views

Cron reinstallation

Can cron be reinstalled? If so, how to take cron job backups created by system and applications like postfix, apache etc., Now after taking backups how to reinstall cron?
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2answers
566 views

Cron job fails for any time other than default * * * * *

On Ubuntu 11.10 (Oneiric Ocelot), my cron job run fine if I use the default * * * * * But if I want it to run at 17 hrs or any other time, it never runs. My settings are: 00 17 * * * wget ...
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1answer
1k views

In what order do cron jobs with the same schedule run?

Let's say that I have the following cron jobs: * * * * * /path/to/taskB * * * * * /path/to/taskC * * * * * /path/to/taskA Is there any guarantee to the order in which they will be run? I've seen ...
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1answer
1k views

How can I prevent two shell scripts running at the same time?

I have a tar backup script that runs once a month. It runs at night through cron. I also have a power schedule that reboots the server at 4.15 every night. The problem is that the server reboots ...
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2answers
1k views

How to get updated IP address mailed to me in DNSExit?

I'm using DNSExit on my Ubuntu server (Natty 11.04) and have installed the ipUpdate rpm file and did an apt-get install for chkconfig to enable the ipUpdate. I'd like to get an email whenever the IP ...
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4answers
4k views

Generic solution to prevent a long cron job from running in parallel?

I am looking for a simple and generic solution that would allow you to execute any script or application in crontab and prevent it from running twice. The solution should be independent on the ...
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4answers
1k views

Cron not able to succesfully change background

I'm running 12.04 with a custom XML background (modification on Day of Ubuntu) that changes based on time of day. I've noticed that there's a significant delay between when the changes are scheduled ...
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2answers
18k views

Crontab not working

I know that this was asked several times, but I don't know what to do... I've tried all the solutions proposed on AskUbuntu, but with no results... So... I have this shell script in my home ...
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1answer
729 views

Cron job not executing?

I'm trying to execute a PHP script every two minutes on my server, but it doesn't seem to be working. I'm using the following cron job: 2 * * * * /usr/bin/php ...
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2answers
4k views

Mutt runng from Crontab

I have a bash script that is sending an email through command line mutt. This bash script is being called from a cron job (setup using crontab -e because of permissions needed to do all items in the ...
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2answers
635 views

Taking timely screenshots of particular sites

I have a website where I have to take weekly screen shots of sister sites. I was wondering how this maybe done. I had obtained the code for taking screen shots but have no idea how to open up the ...
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1answer
4k views

Run Java application as Cron job

I've tried everything I can think and searched high and low for solutions of but I can't get JAVA_HOME into cron to run anything java periodically. In terminal java -version gives me everything ...
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1answer
4k views

Cron not running scripts

I have looked for several reasons that could cause my problem without luck. The issue seems to be extremely particular: my server running LTS 10.04 is not correctly running scripts relating to ...
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1answer
125 views

Is there a way to schedule aptd to check for updates only at certain times?

On Ubuntu 12.04 I've noticed that aptd sometimes uses 100% of a CPU and tends to slow down my whole laptop. I wasn't installing any packages so I'm assuming that this is the automatic update check. ...
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578 views

Is wake up from standby possible via script or schedule? [duplicate]

Is it possible to cause Ubuntu to resume from standby or sleep mode to run a scheduled task like at job/crontab? (hibernation seems to be ruled out in another question) Can a script be written that: ...
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1answer
1k views

How to check when was the last time anacron successfully run?

How can I check when was the last time anacron completed all the daily/weekly/monthly jobs? I understand that the timestamps at /var/spool/anacron are the times anacron started, but it can be that the ...
3
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1answer
836 views

Run /etc/cron.daily/apt at a specific time (i.e. without anacron)

I want to setup a cron job to download up-to-date package only at night. But I found that the cron.daily jobs will be run by anacron if it's installed, so if my computer fails to wake-up at night to ...
3
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1answer
291 views

Good workflow for updating R modules around R-cran updates?

I like that R updates frequently to give me the best new packages, but it does seem to pose a problem for my R scripts on cron schedules. I noticed that every time ubuntu updater updates my r-base ...
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1answer
226 views

Why does mplayer freeze when running from Scheduled Tasks?

I've been trying to use Scheduled Tasks and mplayer as an alarm clock, scheduling mplayer /path/to/file.mp3 for my morning wakeup time, but whenever it reaches the scheduled time, mplayer freezes only ...
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1answer
1k views

run .profile function as cron job

In the .profile file of the root user I have defined a function, e.g. function printDate() { date } I want to run this function every minute and append the output to cron.log. I tried adding the ...
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2answers
53k views

Script doesn't run via crontab but works fine standalone

I have a script that reminds me to restart my computer if uptime is more than, say 3 days (although its set to 0 days now just to check if the script is running as my computer has been up only over a ...
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3answers
918 views

Crontab -e gives me error messages

I get a bunch of error messages when I run crontab -e Here are the error messages. And here is my crontab file under `/usr/bin/': # /etc/crontab: system-wide crontab # Unlike any other crontab you ...
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3answers
258 views

Do I have to set up mail for Ubuntu to be able to mail users?

I remember Debian automatically sending mail to users (to report a failed sudo authentication attempt, for example). On Ubuntu is mail of some kind automatically set up? I created a cron job, and ...
5
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1answer
704 views

What is the easiest way to set up a cron job?

Every time I set up a cron job there is something wrong with it and I spend a lot of time trouble shooting it. I use Ubuntu and I would like to know what tools exist to make my life easier when ...
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3answers
10k views

Daily cron job not running

A quick overview: I have a script that will daily backup my source code repository from SVN into a tarball for that day. I have tested the script and it works very well as long as I run it as sudo, ...
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1answer
325 views

Scheduled tasks won't start

I am quite new to the world of Ubuntu (11.04 is my version), so please bear with me if I do not give all the necessary details to help you help me. I constantly record radio streaming on the Internet ...
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2answers
1k views

Why is git not using my pubkey with crontab?

To backup my sql database I have a cron job running that makes a mysql dump. Now I want to create another cron job that commits this dump to the repo, the problem now is that it doesn't work. In the ...
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2answers
1k views

crontab command not run

I'm trying to get execute a cron job everyday at noon but i can't get it to run. To test it i even tried something like a simple create command but it never runs, it seems as if the file isn't even ...
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1answer
56 views

at job facility for anacron?

Is there a tool for Ubuntu to schedule jobs similar to at but for anacron instead if plain cron? Eg. echo "rm -Rf /tmp/workdata.$$.*" | at now + 99 minutes It doesn't have to be via anacron, just ...
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1answer
451 views

Managing cron.*

I see that Ubuntu uses /etc/cron.{daily,weekly,monthly} for cron jobs. I also see that some things, like updatedb from mlocate, put their jobs there: $ dpkg -L mlocate|grep y/m ...
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1answer
385 views

Is it necessary to monitor cron/anacron?

I use Ubuntu at home for my personal matters, not as a "server". I shut down my computer two or three times a day and there aren't any fixed usage times. I understand that there are automated tasks ...
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2answers
1k views

NMCLI works in script when I run itdirectly , but not when run in CRON

This is under Ubuntu 11.10 I have a script that starts a PPTP VPN connection fetches a couple of files, then closes the connection. When I run this script from a terminal prompt it works perfectly; ...
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2answers
226 views

How can I automate the backing up of cron jobs?

In the even of a crash I realize that I may not be backing up system and user cron jobs. How can I automate the backing up of my systems cron jobs?
2
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1answer
177 views

Script not working through Cron - JDK version mismatch between shell and script

I am executing a script through cron using the below command: */10 * * * * cd /nas/app/someFolder/psox; ./RunPSOX.sh >> /tmp/trial.log 2>&1 This is being executed by root user. All ...
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3answers
1k views

What is the easiest, most effective backup system for Ubuntu Servers?

I'm trying to backup my /var/www/ folder, MySQL, and any other special documents like in the /etc/apache2/ folder. Does anyone have any solutions for backup software? Maybe something that's ...
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1answer
1k views

How to run gui app from cron as root?

The following works in cron: * * * * * non-root-user export DISPLAY=:0.0; zenity --info And displays a zenity dialog on non-root-user's desktop each minute. But if I do the following: * * * * ...