Questions tagged [cron]

Cron is a job scheduler that allows users to run commands periodically.

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votes
4answers
3k views

command for counting number of active cron jobs in crontabs

Problem statement I have 5 solaris boxes, some have Solaris 10 and some have Solaris 9. All of them have many cronjobs in their crontabs. I would like to know number of active cronjobs available, so ...
2
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2answers
2k views

Is crontab related to server performance?

I am using Solaris 10, and I am adding many cronjobs to my server's crontab. Currently I have 30 cronjobs in my crontab. one cronjob takes 8 hours to complete ,one other cron job takes 5 hours to ...
4
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2answers
2k views

cifs write errors in cron job

EDIT: THE SOLUTION With Tim's help I determined that larger writes of data were failing versus smaller ones. Why they didn't fail when I ran the script interactively, I don't know...But here was the ...
8
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2answers
6k views

Open emacs in a terminal when editing crontab

I have setup emacs as my default editor in /etc/profile. When I want to use emacs in a terminal. I open it with the -nw option. How can I have the same behavior when doing a crontab -e preventing it ...
7
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2answers
11k views

How can I know when a cron job was killed or it crashed?

Usually when a cron job crash, it will leave some error messages in the log. We run shell script and some java program with cron job. Recently we found some weird thing out from the log. Obviously ...
3
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4answers
1k views

Is there any handy command line tool to manage Cron jobs?

Would someone suggest any handy command line (NOT web) tool or script which adds, enables and disables Cron jobs? I am looking, for example, for the following (or similar) behavior: sh manageCron.sh -...
12
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2answers
26k views

Can I change the default mail recipient on cron jobs?

I believe that if there is any output from a cronjob it is mailed to the user who the job belongs to. I think you can also add something like MAILTO=vivek@nixcraft.in at the top of the cron file to ...
1
vote
1answer
2k views

grep searchstring /etc/crontab strange behavior in BASH script

I am working on a BASH script which creates automated backups via the crontab. I am trying to use myVARIABLE=`grep backup /etc/crontab` to return lines containing "backup" if an entry has already ...
2
votes
1answer
82 views

App which can execute arbitrary code on different events

I've been looking for a simple activator which can execute some code when stuff happens, I haven't found anything yet. Maybe, I am not using the right keywords. It would be great if someone pointed me ...
22
votes
3answers
20k views

Are multiple @daily crontab entries processed in order, serially?

I want two jobs to run sometime every day, serially, in exactly the order I specify. Will this crontab reliably do what I want? @daily job1 @daily job2 I'm assuming they run one after the other, but ...
7
votes
3answers
14k views

/etc/crontab what does “test -x” stand for

In my /etc/crontab file I have: # m h dom mon dow user command 17 * * * * root cd / && run-parts --report /etc/cron.hourly 25 6 * * * root test -x /usr/sbin/anacron || ( cd / &&...
6
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2answers
4k views

How to access X display from a cron job when using gdm3? [duplicate]

Possible Duplicate: Open a window on a remote X display (why “Cannot open display”)? I'm trying to run a cron job that needs access to my X session. I know my X session will always be ...
6
votes
2answers
493 views

cron every X exact meaning

In cron you can specify */n where n means every n times period, for instance in the first column is minute. */5 means every 5 minutes, but which minutes? 0, 5, 10, ...? What happens if the number ...
4
votes
1answer
640 views

Using rsync + cron to sync a machine behind a firewall with my dropbox

I have a machine (A) behind a firewall with no access to the Internet, on this machine I can NFS mount directories on another machine (B) which can access internet, and is accessible from Internet, ...
0
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2answers
3k views

Running Python script via cron with sudo?

Im using Linux Mint. I have written a python script that is designed to not be accessible to the logged in standard user but is still be executed while they are logged in. It is to run and log them ...
2
votes
3answers
1k views

Why does Crontab give me an error with my PHP script when running it from the terminal does not?

I'm having some problems with running the Crontab with PHP files. I have this same php scripts running in the Crontab for more than 6 months but some days ago mysteriously they stopped to execute the ...
2
votes
1answer
3k views

crontab “0/15” minutes + “11-15” hour field: when does that end?

Given a crontab expression like "0 0/15 11-15 ? * MON-FRI", how is that parsed? I am correct in assuming the 11-15 does not mean "between 11 and 15" but "when the hour is 11-15, inclusive" - i.e. ...
1
vote
1answer
6k views

How to remove obsoleted logs with logrotate?

I wanted to remove unnecessary logs automatically , like Xorg.log.0 , and other packed *.gz files , i really don't need that on a laptop system. However , i checked man logrotate , but only an entry ...
3
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2answers
11k views

How to start the cron daemon

I am using RHEL 5.4 I killed the cron daemon accidentally. I wanted to stop a cron task, didn't know how to do it, ended up killing the cron daemon itself. How do I start it again?
5
votes
2answers
4k views

How to run a cronjob in my regular environment?

Both the shell and environment variables that cronjobs are run in is completely different from the ones presented to me in gnome-terminal. How can I run a cronjob under the same circumstances as if I ...
2
votes
1answer
321 views

Need to find a cronjob

I have a problem, some user ,and I'm not sure who, on one of my servers wrote a cronjob that executes every night at midnight. The cronjob creates a sql dump of a database which is then grabbed by ...
0
votes
1answer
727 views

Is there a way to combine a file with crontab?

I'm trying to create an interface that will show a message on the screen every set time. Cron is an ideal tool for this case only it doesn't read data from a file during it's run (as far as I could ...
2
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3answers
3k views

Is crontab multithread? [closed]

I don't know where I can find more information about crontab, so I ask here. Crontab is it multithread? How does it work?
4
votes
1answer
2k views

How to use cron + python to regularly adjust screen brightness?

I want to use cron and this script (http://askubuntu.com/questions/23593/use-webcam-to-sense-lighting-condition-and-adjust-screen-brightness): import opencv import opencv.highgui import time import ...
3
votes
1answer
2k views

Scheduled task on reboot

How can I schedule a task to run on next reboot? I understand that we have tools like cron and at to help with scheduling. But they seem to allow scheduling at a specific time and not on specific ...
2
votes
1answer
424 views

Cron & Gnu Screen - Trouble with detached screen [duplicate]

Possible Duplicate: sending text input to a detached screen I have a script for my Minecraft server that runs automatically every 15 minutes. The problem is that after a server reboot, minecraft ...
12
votes
6answers
6k views

CronJob every 25 minutes

I want to know whether there is any easier way to run a job every 25 minutes. In cronjob, if you specify the minute parameter as */25, it'll run only on 25th and 50th minute of every hour
13
votes
2answers
4k views

How can I delete all files in a folder that haven't been accessed in a certain amount of time?

I'd like to run a nightly cron job that deletes all the files in a folder that haven't been accessed in a week or more. What is the most efficient way to do this in bash?
2
votes
1answer
359 views

Can I bypass crontab command by putting the file?

I need to create and put my cron file with cat cronfile1 cronfile2 > cronfile crontab cronfile -u myuser This works for me, but I want to know if I can do directly cat cronfile1 cronfile2 > /...
4
votes
5answers
2k views

how to ensure a program is always running but without root access?

Currently I need to have a program running all the time, but when the server is rebooted I need to manually run the program. And sometimes I'm not available when that happens. I can't use a normal ...
12
votes
2answers
14k views

Bash Script on Startup? (Linux)

Is there any way to make/run a bash script on reboot (like in Debian/Ubuntu for instance, since thats what my 2 boxes at home have) Also, any recommended guides for doing cron jobs? I'm completely ...
1
vote
1answer
330 views

How to list the actual cronjobs?

If I (e.g.: under Fedora) edit the crontab file with vim, then I restart crond: /etc/init.d/crond restart then the actual crontab file: "/etc/crontab" is the same as the actual cronjobs in reality. ...
3
votes
1answer
3k views

cron not executing?

I have the following cron tab installed: crontab -l # m h dom mon dow command */10 * * * * "echo" >> /tmp/cron.log The server is at rackspace, it's a cloud server: Linux myserver #8 SMP ...
2
votes
1answer
2k views

Cron: My crontabs don't seem to be doing anything at all

I think I'm missing something. I've set up some crontabs to handle rsyncs over ssh in my office to handle some backups, but they don't seem to be running OR logging, for that matter. Am I missing ...
3
votes
1answer
2k views

Are changes in crontab applied when the file is saved, or when the editor is closed?

When I do crontab -e, are the changes applied immediately when I save the file, or do I have to exit vim for it to be applied?
1
vote
3answers
443 views

Cron with a 12-hour issue?

I have a cron job that's managed through plesk. I'm being told that it's being executed twice in a day, once at 5AM and once at 5PM, based on the email that's being received. Here's the cron line: ...
12
votes
3answers
58k views

executing a sh script from the cron

I have a test.sh script #!/bin/sh php /home/v/file.php sh /root/x/some.sh when I execute the file as root from command line it works. sh /home/v/test.sh when I set it to crontab -e (is the root ...
1
vote
2answers
1k views

using cron to run script

Hey guys, im trying to run a script using cron, im using a crontab created by the user ashtanga, in the crontab i have */5 * * * * /home/custom-django-projects/SiteMonitor/sender.py in top of the ...
2
votes
1answer
198 views

Stop cron script from destroying my mirrorlist with invalid data

I have to following cron script that runs daily. As you should be able to see from the code, it outputs the results from reflector to /etc/pacman.d/mirrorlist. $ cat /etc/cron.daily/update-mirrorlist ...