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

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Incrontab does not execute command

When I use incrontab out of the box, I mean no changes, I get no result, as if the command was not executed. my incron line is : /crrae IN_CREATE,IN_CLOSE_WRITE,IN_MOVED_TO /usr/bin/unix2dos $# the ...
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System Crontab or Root Crontab

System crontab: /etc/crontab Root crontab: sudo crontab -u root -e Which way is preferred? As they all run tasks within administration privilege.
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3k views

Automating backups run from a bash script in Linux the right way

I have a bash script I wrote to backup a Moodle installation. It works fine, I've tested the backups, but there's a problem with it; when I do the backups, since I have to use sudo to type the ...
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1answer
6k views

Executing PHP with CronJobs in CentOS 6.4 not working?

So I've spent around 2-3 hours now and some times researching, I found several of the same responses online but none seem to work! I'm trying to execute a PHP script every minute (as a test), but it ...
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1answer
2k views

How to set up a cron entry that runs at 00 and 30 after the hour?

I have a cron entry that runs every 30 minutes - */30 * * * * /home/myuser/myscripts.sh How to set this up such that it runs exactly at 30 minute intervals but also exactly at (for example) 3:00 ...
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2answers
721 views

Running a cron job from another shell

I would like cron to run a script from a specific shell (Zsh). I thought the following would work: 00 02 * * * exec zsh; /path/to/script.sh but apparently it doesn't, why? This also made me ...
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31 views

How to block the user for a certain amount of time

Suppose, I am working in X environment, and I want to have an obligatory periodic rest. Is it possible to setup a root cron job, that will block my user for 5 minutes every 45 minutes? I am using ...
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1answer
1k views

Why do deleted files continually reappear?

I've been having a strange issue recently, where I would delete files from a location (i.e. Desktop), and then empty the Trash. However, a day or so later (I'm not sure exactly what triggers it), the ...
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4k views

why daily cron isn't running on CentOS 6?

I have a daily cronjob set up on CentOS 6 OS which should look after the log rotation job. The file is /etc/cron.daily/logrotate and it's contents are #!/bin/sh /usr/sbin/logrotate ...
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1answer
240 views

security concern around adding cron user to web application group

I have a permissions issue on my CentOS 5.6 machine with regards to the cron user. On my test/staging environment my cron user (picco-cron) is a member of one group - picco-cron, as below: ...
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1answer
728 views

Why CRONTAB tasks are lost when quit Putty session? [closed]

I logged to remote computer, running under Solaris, using Putty and added some jobs to be run by cron. When I quit console and logged once again all jobs was lost. crontab -l myuser How do I ...
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1k views

automate updates with a bash script and cron

I'm trying to automatize the updates of debian system, without making upgrades. Then i'll send an e-mail to me, everytime there is an upgrade available. I've tryied to do it with cron-apt, but i ...
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674 views

CRON Permission Denied [closed]

I have a Debian 7. 3 Server with WebMin installed. I configured a cron job to run every minute as root user, so I run the command crontab -l when I'm logged in as root it shows: * * * * * ...
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4answers
3k views

Crontab not working

I'm trying execute a basic shutdown crontab to run M-F at 10PM. So I did the following: sudo crontab -e Once inside of the crontab I added the following line: 0 22 * * 1-5 shutdown now The job ...
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1answer
347 views

How could I signal to a cron job to skip runs?

I have a cron job that runs every X mins and that I would like to have a way to "signal" it not to do anything if needed. Is there a standard way for this? The only idea I had is to check some ...
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2answers
635 views

Does cron know that the instance to be scheduled is already running?

I was wondering if we add a job in the crontab e.g. to run every 5 mins and the job does not actually manage to finish in 5 mins, does the cron daemon know that the previous instance is already ...
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2answers
613 views

Crontab not triggered

I have a program written in C with OpenCV. It captures an image from the webcam and saves on the disk with the name given as an argument. I want to trigger it every minute, thus I inserted the ...
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1answer
3k views

Getting a Bad Hour Error in crontab

I am getting Bad Hour error for below peice of code in crontab */05 17-05 * * * wget -q -O /dev/null "http://abcd/cron/abcd" Is there any issue with this. I want the cron to run from evening 5 PM ...
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1answer
2k views

Cron task starts at 5:30 and runs every 5 mins once

I want to run a crontab cron job which start at 5:30 AM and runs every 5 mins. How do i set it up in Linux? I am able to give like below. But how do i make it 5:30 ? */05 5-16 * * *
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1answer
377 views

Accidentally typed crontab with just the dash

What happens when I type just "crontab -"? The "e" didn't take before I hit Enter. It just moved the cursor to the next line and I had to Ctrl+C to exit, but I'm not sure what it did exactly. I'm on ...
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1answer
274 views

Can continually assigning a variable in a shell script cause a memory leak?

I've written a short script to copy Apache's server status to a log: #Save date and time to a variable dt=$(date) #Echo date and time to the log file as it's not included in server-status echo "Time ...
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1answer
850 views

Cron: Client does not have permissions to send as this sender

Platform: Arch Linux Cron: cronie Mail: msmtp I discovered that sending cron output to a mailbox hosted by Office 365 produced the following error, even though sending mail through the CLI was ...
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1answer
330 views

Cron task in graphic interface

I need to open one (or more) browser tab periodically and I decided to use cron. The command in the shell (bash) that correctly executes this task is chromium-browser http://mysite.com. If I type it, ...
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2answers
174 views

How can I ensure that a custom environment variable is set before cron runs a task?

I recently experienced a logwatch issue that is fixed by running export DATE_MANIP=DM5. cron seems to forget this when I logout (presumably because it's not saved). Where can I add this custom ...
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1answer
315 views

What's the easiest way to set up a 2-hour alarm?

I want my computer to play some given .mp3 every 2 hours. I want it to run at startup, and be modifiable with a given .conf file. The choice of .mp3 will also be in the .conf file. The reason is, I ...
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2answers
146 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 ...
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1answer
120 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 ...
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1answer
223 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 ...
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2answers
258 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? ...
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5k 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 ...
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1answer
26k 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 ...
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2answers
6k 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 ...
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3answers
1k 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 * * ...
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1answer
117 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 ...
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3answers
530 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 ...
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2answers
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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 ...
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1answer
200 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 ...
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2answers
654 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 ...
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4answers
3k 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 ...
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1answer
952 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 ...
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1answer
583 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 ...
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1answer
164 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. ...
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1answer
205 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 ...
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1answer
101 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 ...
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2answers
5k 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), ...
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2answers
1k 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
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2answers
564 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 ...
6
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2answers
12k 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 ...
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1answer
1k 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: ...
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630 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 ...