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

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3
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2answers
87 views

How to run a command as if it is called from cron

I write a script and set it as a cron job. But due to a difference of environment variables it doesn't work as it should be. In that case I change a little bit with crontab -e and set a cron job time ...
0
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1answer
50 views

Crontab in Daylight Savings

This weekend with daylight savings, we had a situation that when the system clock hit 3:00am from the jump, we had hundreds of processes fire off out of the crontab. Everything I'm reading says that ...
9
votes
1answer
201 views

Cronjob to Run and then Terminate

I want to add a cron entry that does something like: 00 00 * * * * /tmp/script.sh Is there something I can add to the end of the line, so that when it is finished, it will remove the line out of my ...
1
vote
1answer
231 views

Why does redirection in crontab result in a zero byte file?

System: Xubuntu 13.10 When I have this crontab entry */5 * * * * cat /home/dbk/.bash_aliases &> /home/dbk/Desktop/junk junk has a byte size of 0. Running $ cat /home/dbk/.bash_aliases ...
7
votes
7answers
2k views

cron Vs. sleep - which is the better one in terms of efficient cpu/memory utilization?

The Case: I need to run some commands/script at certain intervals of time and for this I have two options - 1. set up a cron-job or, 2. implement a loop with sleep in the script itself. Question: ...
4
votes
1answer
12k views

Crontab job start +1 min after @reboot

Need a script executed at each reboot in +1 minute. I placed a record @reboot but it is too early for my script. How to execute it sometime after reboot?
0
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2answers
62 views

Cron Job - Log Each Minutes Activity [duplicate]

I have some cron jobs set up to run, some of them each minute. I know I can log them to text files by simply putting php /path/to/file.php > /var/logs/something.txt but can I do this every minute? ...
1
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0answers
2k views

Trying to kill cron job processes found by “ps ax | grep keyword” logged in as pi user

I'm trying to kill several processes from the command line logged into the pi as the user pi. All of the processes have been started by cronjobs, so they should belong to the root user. I'm running ...
1
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1answer
1k views

As root, how can I list the crontabs for all users?

I have a script being run automatically that I can't find in the crontab for the expected users, so I'd like to search all users' crontabs for it. Essentially I want to run a crontab -l for all ...
2
votes
2answers
600 views

How come crontab -e is different from less /etc/crontab?

Im pretty new to unix and crons, I was currently about to try to add crons to an existing cron file. I read you could do this with crontab -e. The confusing thing to me is just that crontab -e shows ...
1
vote
3answers
67 views

variables in crontab [duplicate]

On our linux server we have a lot of entries. Many entries look like this: 15 13 * * 3 /very/long/path/to/binary/run.sh ... These entries would be easier to maintain if I could write: 15 13 * * ...
1
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1answer
87 views

Help with “crontab -e” [duplicate]

I'm trying to learn a little about cron and would appreciate some help. I edited crontab -e to have this line: */10 * * * * /usr/bin/touch /home/dkb/Desktop/test.txt It works and I see ...
3
votes
3answers
230 views

Setting up a cron for every 30 hours in Debian

*/30 */30 * * * python /root/get_top.py I'm trying to run a script every 30 hours and 30 minutes. Is the syntax above proper for that? I've had multiple people tell me that */30 is not a valid ...
0
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2answers
4k views

Is a restart of cron or crond necessary after each new schedule addition or modification?

When I schedule a job, some seem to be applied immediately, while others after a reboot. So is it recommended to restart cron (crond) after adding a new cron job? How to do that properly (esp. in a ...
-3
votes
1answer
88 views

Is there a better way to stop and restart Apache server every 30 minutes? [closed]

I have to stop and restart Apache every 30 minutes in order to avoid it becoming extremely slow over time. The cron job that I use as follows: @echo off rem Launch google.com, wait 2 seconds, then ...
2
votes
2answers
243 views

Running cron.daily in parallel

Being able to put a script in /etc/cron.daily is really nice because I can do it easily from a configuration management system or a package. However, my understanding is that all the entries in ...
2
votes
4answers
546 views

Cron not running my script

I'm not sure why but my app never executes when I reboot my machine. In crontab > crontab -e I see @reboot /root/myscriptname.sh The file is #!/bin/bash nohup mono-sgen /root/myapp.exe ...
1
vote
1answer
317 views

Use /etc/init.d/fetchmail with the personnal ~/.fetchmailrc

Now, I have two users in my system using fetchmail with a personal ~/.fetchmailrc and syncing there mails with the command fetchmail -kv --uidl -m '\''/usr/bin/procmail -d %T'\ (In a cron but this ...
1
vote
1answer
209 views

Logrotate not picking up or acting on new configuration file

I had a logrotate configuration file set up for a log (let's call it Log1). It is working fine and the log is rotating everyday as expected. Yesterday I cloned this set up and modified it for three ...
1
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0answers
33 views

Why am I not receiving any system e-mails? [closed]

In my crontab, I have the following: * * * * * sh /home/rimmer/test.sh In /home/rimmer/test.sh I have the following: #!/bin/bash echo 'test'; I have also set chmod +x /home/rimmer/test.sh, of ...
2
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3answers
2k views

Installing crontab using bash script

I have created a script to install two scripts on to the crontab. #!/bin/bash sudo crontab -l > mycron #echo new cron into cron file echo "*/05 * * * * bash ...
1
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1answer
114 views

Debian, nonroot, cron, bash script and rebooting at specific time

As nonroot user, how can I schedule a reboot every day at 4:30am? 30 04 * * * /home/user/scripts/reboot.sh As a nonroot normal user, I'm sure the system won't allow me to use the reboot command. ...
1
vote
1answer
104 views

crontab is giving only 2045 lines of output instead of 6000 lines

I am executing one shell script with crontab which has to give more than 6000 lines output only it is giving output up to 2045 lines then coming out. when I run that shell script it is working fine ...
1
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1answer
53 views

Is it possible to use the at command to schedule a job to run at a given timestamp?

I want to schedule a file to run using the at command, as described in this tutorial. I see that the at command supports the posix format -- but I don't see any mention of timestamps. Surely it is ...
0
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2answers
2k views

Cron job is not working [closed]

i have a cron job center code hereonfigured at var/spool/cron/testuser, Am calling "adindex.sh" file from there. Am getting results when am directly put the command directly in prompt(php and sh), ...
2
votes
2answers
710 views

How can a normal user trigger a root cron task to execute immediately, without delay?

I have a root cron task that runs every day. But I want to allow normal users to request that it run immediately, if they so wish. It is a harmless process and it can run as often as needed and these ...
2
votes
2answers
251 views

How can I manage my crontab effectively to avoid issue by multiple updates by multiple users?

I have a crontab that includes many users updating it. The problem is that because of this, it is not easy to know who did what modification of a cronjob. I was thinking to create a script to do a ...
4
votes
2answers
4k views

How to find a cron job if you know the specific time it runs?

I've been using kSar to look at my servers resource use. There is a definite spike in process creation at 4:04AM daily. Cron seems to define the interval they should be run, but not the specific time ...
0
votes
1answer
384 views

what does mean crond[2113] : (*system*) RELOAD (/etc/cron.d/mycron)

crond[2113] : (*system*) RELOAD (/etc/cron.d/mycron) My cron job is not working and I got the error above in log, What does mean that, how can I know what is going on. My cron job code: ...
0
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0answers
262 views

“No space left on device” - plenty of space and inodes left [closed]

I am using amazon linux on an ec2 instance. I am running a cron script as root that copies files to a different directory on the same machine, but some of the file copies are failing with a "no space ...
0
votes
1answer
146 views

cron runs job at unexpected times

I have set up a cron job on my local Ubuntu 12.04 server to log on a remote server through a passwordless ssh connection and run mysqldump on a database on that server once a day. My problem is that, ...
0
votes
2answers
268 views

using mergecap for set of files

Im trying to use mergecap to merge 15 old pcap files in a folder. I tried to use FILES=($(find /mnt/md0/capture/DCN/ -maxdepth 1 -type f -name "*.pcap" -print0 | xargs -0 ls -lt | tail -15 | awk ...
0
votes
1answer
102 views

How to get cron to delete files with names starting with foo and file extensions ending with bar? - done with php script

I'm sorry to post such a question but honestly, I've spent hours reading posts and still it doesn't work... Also if this should be posted else where but this felt like the right place. I have a ...
1
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2answers
220 views

Neither crontab nor anacron is running, how to debug?

I'm running Arch ARM on a PogoPlug and want to execute a file every hour, the file when call directly runs fine (it is executable), for testing the file /etc/cron.hourly/crontest contains ...
1
vote
3answers
466 views

dpkg-reconfigure: not found when running in cron

I have a virtual server (debian) and the clock fails to sync from time to time (probably because i save/restore state with vboxheadlesstray). To fix this issue I run dpkg-reconfigure ntp && ...
2
votes
1answer
4k views

Root Cron Won't Run Script (permission denied)

I've edited my root cron tab to periodically execute a script located in a particular user's folder using this command: sudo crontab -e When cron runs the script, this is the output: sh: 1: ...
7
votes
3answers
2k views

Using notify-send with cron

I am using Arch Linux with KDE/Awesome WM. I am trying to get notify-send to work with cron. I have tried setting DISPLAY/XAUTHORITY variables, and running notify-send with "sudo -u", all without ...
0
votes
1answer
26 views

Are the crontabs of users linked?

Our Linux server has a community user that has a crontab for itself. The admins don't want me to schedule my scripts on their crontab because they don't want to take responsibility for my programming. ...
0
votes
1answer
19 views

crontab nodification is taking too much time

There are 300 processes configured in a single Linux server's crontab. if I want to stop or modify any of them, I have to comment them out (i.e. # ..cron..) for all processes. It's a time consuming ...
1
vote
1answer
467 views

What does /etc/cron.daily/apt do?

Could someone explain what the apt script is doing in cron.daily please? I can't find any documentation on it. NOTE: I'm trying to investigate a server-server communications issue which frequently ...
15
votes
6answers
38k views

Why did my crontab not trigger?

I used crontab -e to add the following line to my crontab: * * * * * echo hi >> /home/myusername/test Yet, I don't see that the test file is written to. Is this a permission problem, or is ...
1
vote
1answer
79 views

Execution behaviour of cron

I want to schedule a cron so as to avoid running at midnight. I was thinking a period of 7 minutes. Now, I figured out with 7 minutes of interval, the last cron schedule for a particular day would be ...
1
vote
2answers
253 views

Script from cron doesn't create archive

I'm using: # cat /etc/redhat-release CentOS release 6.4 (Final) Have an script in user's crontab: $ crontab -l 0 7 * * * /home/teamcity/scripts/TC_backup.sh If I run this script under this very ...
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0answers
68 views

Create a fake read only device like file with incrond

I need to generate UUID with uuidgen (not through any function call, but external command, because processes which will read the file cannot call any APIs or external commands directly). My idea is ...
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0answers
25 views

Run Xdotool on multiple users at once

When running Xdotool on user one (cron): * * * * * export DISPLAY=:0 && xdotool mousemove 10 10 and I switch to user two for several hours, and back to user one, I find out Xdotool not ...
1
vote
1answer
5k views

running a script every 30 minutes with crontab using ROOT (Debian)

When I manually type: root@username:~# ./myscript.sh the script executes, however I tried the following combinations to have crontab execute myscript.sh every 30 minutes (forever) and none seem to ...
0
votes
1answer
2k views

What causes cron to continuously send mail and how can I disable it?

I have a problem on CentOS 6.3 system where the crond process tries to unsuccessfully send mail over and over (at least I think this is what its doing) until the OS eventually generates a "too many ...
2
votes
1answer
1k views

“stdin: is not a tty” mails for running scripts as cron jobs

I have several shell scripts (bash) which are started by cron. Every time a script is executed I get an email saying "stdin: is not a tty". Can someone please tell me how to fix this? All scripts run ...
1
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0answers
38 views

Unplug AC causes anacron to stop. No resumumption if cron.daily had already started?

Anacron is started/stopped by a number of means, one of which is when AC power is plugged/unplugged, as can be seen by examining /etc/apm/event.d/anacron and /usr/lib/pm-utils/power.d/anacron. You can ...
1
vote
1answer
241 views

Rotating iptables logs, strange message about script being converted to upstart job

I use a script /etc/logrotate.d/iptables containing entries like: /var/log/in_iptables.log { rotate 4 weekly missingok notifempty compress ...