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Questions tagged [cron]

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

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Run a tmux new session with cron, then run a command

I have in my cron that auto starts a service inside a tmux if it detects that its not running. The rest of my bash script works, but if the tmux session doesn't exist, it throws an error. Which is why ...
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Does cron run graphical applications as root?

I've automated a daily restart for Firefox (edited by running crontab -e) and forgot to take into account whether the program would launch with administrator privileges. killall -s SIGTERM firefox; ...
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xdotool returning different output when executed from crontab [duplicate]

So I was making a script that monitors my app usage. It does so by running a cronjob every minute, and cronjob in question checks which window is focused on and increments its counter by 1. Other ...
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CentOS Linux 7 cronjob validate the expression and check if it will run

I do have a CentOS Linux 7. On /etc/crontab I added my command that I want to run: 0 0 20 * * root MySpecificCommand I do have three questions: How can I check if my expression is valid and and what ...
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Debian - Execute a python script with modules import

In Debian 10 (buster) I wan't to schedule a task with cron. This task is a python script who create a csv file. This python script start with: import xmlrpc.client import csv When I execute it, ...
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cron is no longer logging, but it seems to be running

I am running Ubuntu 20.04 as a server on a remote machine. I have confirmed that cron is running as a service: $ sudo service cron status ● cron.service - Regular background program processing daemon ...
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Struggling with du, php and crontab

Unix numpty here. I have written a PHP script which I am running from a crontab every so often. Part of the script is a du command from which I extract certain directory sizes which I put into a JSON ...
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Can I run a script on reboot once?

CentOS9 Keeping in mind this question: https://serverfault.com/questions/1099284/centos-how-to-keep-previous-service-state-on-reboot It seems that it is not possible to achieve what I need. Is that ...
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A basic Bash script (to start a GUI program) works partially in cron

I use this script to restart Firefox overnight (to apply the package manager and addon updates): #!/bin/bash killall -s SIGTERM firefox; sleep 15 firefox -P "user" & firefox -P "...
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Scheduled cron job not running on MacOS [duplicate]

Here is my crontab. 3 13 * * 1-5 * * * * * /Users/smveerap/cron.sh >/tmp/cronStdout.log 2>/tmp/cronStderr.log 0 12 * * 1-5 * * * * * /opt/homebrew/bin/python3 ~/git/bashFiles/gitUpdate.py >/...
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Wildcard expansion doesn't happen when Bash script invoked from cron under macOS

I have a Mac mini running macOS Monterey, and it has InfluxDB running in a Docker container. I'm trying to set up a nightly cronjob via a shell script I'm calling to back the data up, zip it, and only ...
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What effect does a dot character . have in a crontab?

I have picked up a habit of including . from some blog post: 0 0 * * * . /usr/local/bin/somescript.sh ...instead of: 0 0 * * * /usr/local/bin/somescript.sh For instance a visual cron schedule ...
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Bash variable is empty depending on cron schedule frequency. If every 1, 5, 15, or 10 minutes, there is a value. If every 30 or top of hour, empty

I've got a cron scheduled bash script I am seeing odd behavior with. As the title says, there is a single variable that is either empty or not after the script runs depending on the cron schedule. If ...
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Python Scrips on Raspberry - ssh works, cronjob doesn't

I wrote a python script that checks a website and eventually sends an email. I copied the script to my raspberry and when I execute it via ssh it works fine. But when I let it execute by the crontab ...
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POSIX (or portable) way to forward emails from crontab

I've got an installer/updater script that's meant for IRIX/Linux/macOS/FreeBSD and I would like to extend its compatibility to Solaris. I've already fixed a few parts that weren't POSIX compliant, ...
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crontab doesn't create screen session

I am trying to use @reboot /usr/bin/screen -dmS nfc /home/pi/.nvm/versions/node/v17.8.0/bin/npm run --prefix /home/pi/nfc/ dev to run my script in /home/pi/nfc/ on startup. Sadly after rebooting, I ...
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Audio in Qt6 application does not work if run from cron of systemd

Ubuntu 21.10, Qt 6.2.0. In my QML I have a MediaPlayer: MediaPlayer { id: mediaPlayer videoOutput: videoOutput audioOutput: audioOutput onErrorOccurred: { console.log(mediaPlayer....
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How can I get Vim to give me different tab settings for crontab?

I would like to be able to keep the temporal expressions in my crontab neatly organized in columns, with a key above every 5 or so entries, like so: #m h dom mon dow command 30 6 * * * /...
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RHEL 7 - Crontab runs only under /etc/cron.d

noobs here. As my first step I edited the crontab as usually: # crontab -e 0 2 * * * /root/backup.sh The above, for some reason, never starts. Instead, if I create a backup job under /etc/cron.d, the ...
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ModuleNotFoundError

The problem is that when the script is running through cron, for some reason the module is not found, but if you run it directly through Python, then everything is fine Cron: */5 * * * * python /home/...
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rtcwake not executed as root cron job

This rtcwake job launched manually works fine : $ sudo rtcwake -m no -u -t $(date +%s -d 'tomorrow 07:30') but doesn't seem to run as a root cron job : $ sudo crontab -l 32 7 * * * rtcwake -m no -u -...
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I need to run custom processes with crontabs

I need to run custom processes with cron-tabs, every 15 days but varying the day, for example 00 18 */15 * 4 00 1 */15 * 1 The days are never fixed, they always vary, is this possible? Thank you
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Extracting columns added during the last minute from the csv file

I wrote a script that runs sql * loader every minute to drop the data from the csv file into the database. However, it needs this script to extract data from the last minute csv file, and not read ...
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mdadm rotate hot spare

It can be a good idea to have a hot spare in some RAID systems. It can be a bad idea for the hot spare to sit idle for months/years, potentially hiding a defect, until an active drive fails and ...
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CRON 2>&1 >/dev/null vs >/dev/null 2>&1 [duplicate]

I just created a tiny shell script to be run every minute. What happened was that it started flooding my mail. $ crontab -l * * * * * /home/user/bin/test 2>&1 >/dev/null I changed the ...
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1 vote
1 answer
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How to run a command from terminal so that it will be executed without tty?

The situation: I have a bash script that is intended to run with cron. I tested the script on the terminal and it was running fine. As I configured the script to be executed by cron, the script ...
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Debian - Schedule a SQL query with crontab

I wan't to schedule a SQL query in a PostgreSQL database with a crontab. In terminal, in root, when I run: psql -U postgres -d my_database -h localhost -p 5432 -c "INSERT INTO schema.table (name) ...
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1 answer
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Is sudo crontab -e and sudo cat /etc/crontab the relevant one for cron?

$ sudo cat /etc/crontab # ...comment lines elided... 0 0,12 * * * root sleep 1347 && certbot renew -q --post-hook 'sudo reboot' sudo crontab -e shows 13 0,12 * * * root sleep 1347 && ...
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Retry cron job on failure

I have a cron job that can fail periodically when resources are not available. Waiting awhile and trying again is the best way to handle such failures. What is the best way to do this? Have the ...
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Crontab is overwritten by HiveOS on boot

I am trying to add some additional cronjobs to a rig running on HiveOS. Every time I add a job to crontab (for example one for duckdns) it disappears after the reboot. I've noticed that the crontab ...
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1 vote
1 answer
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bash script in cronjob cannot execute /sbin/fake-hwclock

I've edited my root crontab to periodically execute a script: sudo crontab -e Which should execute the following script, located on a mounted USB, as root: * * * * * /mnt/usb0/fake-hwclock-cron.sh ...
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3 votes
1 answer
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Crontab scheduling for specific option

I need to add a crontab entry which runs every quarter ,on second sunday ,at 02 am. Which of the below one is correct? the OS is AIX. 00 02 8-14 */3 0 && /myscript.sh or 00 02 8-14 */3 * [...
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1 vote
3 answers
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Running a python script via cron at a random time between 10AM-11PM once every day

I'm on ubuntu and need to run a python script once every day randomly between 10AM-11PM. Right now I've only got it running at a fixed hour, I've seen a few examples but mostly for repetitive tasks ...
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CalendarAgent issues

I am trying to disable CalendarAgent on my MAC; It consumes CPU cycles with no value. I have tried to find the default list of processes that et launched automatically. Need to figure out how to edit ...
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Recently my speedtest-cli only runs as sudo not root?

This has worked in my script for years but now something is goingon. I can run sudo speedtest-cli as any user and it work. As root if I use in cron or execute under root I get this error: Retrieving ...
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schedule cron job for every hour is not working

I am running a single instance cron job for certain task. My script looks like below: # every hour interval 0 * * * * php /project/yii daily/order # every 30 minutes interval */30 * * * * php /...
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1 vote
1 answer
190 views

Cron not sending email, command line email works

I have installed ssmtp on an raspberry pi running Raspbian 10 Buster. Email from the command line, e.g. using mail works fine. However, I have also configured a user's cron job to send email by adding ...
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Anacron kills children of my task

I wanted to set up an anacron task to run a backintime backup once a day (Ubuntu 20.04.3 LTS). If you schedule this using the backintime GUI, the normal crontab is being used, but for my use case this ...
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Why doesn't anacron run the tasks scheduled?

I've set anacron to run several tasks, but it seems to fail due to some sort of weird permissions error. This is my anacrontab: # /etc/anacrontab: configuration file for anacron # See anacron(8) and ...
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Run cron job on linux with http user - Elastic Beanstalk

I have a webserver running Symfony and I want to run a periodically, I also use AWS and AWS Elastic Beanstalk There is documentation where explains how to add a cronjob, although as soon as I add the ...
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Crontab echo job sent to a file doesn't work [duplicate]

I have the crontab job here to echo every minute: * * * * * /bin/echo "hello world!" >> /home/mrpennymiser/echos.txt I am using Kali Linux WSL for Windows. I am using full paths but ...
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1 vote
1 answer
620 views

Cron job to delete all files older than 7 days: -exec rm -f {} \; vs -delete [duplicate]

I want to run a cron job which deletes .txt files older than 7 days. I have two commands. The first command: /usr/bin/find /var/www/example.com/wp-content/targetdir -name "*.txt" -type f -...
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1 answer
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Logrotate scenarios - Mix and match cron.daily and daily directive

The file: /etc/cron.daily/logrotate has the following statement: /usr/sbin/logrotate /etc/logrotate.conf The logrotate.conf file has the weekly directive defined inside. Now I have two rotational ...
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What should be the preferred approach while rotating logs - using the daily directive or putting the file path in cron.daily? [closed]

While doing log rotation, we have two options - Using the daily directive in the logrotate file - /var/log/wtmp { daily minsize 1M create 0664 root utmp rotate 1 } Putting the ...
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1 vote
1 answer
50 views

Print the cron time in human readable format

After researching enough on the times when cron.daily (and weekly and 'hourly') run, I found the following command - grep run-parts /etc/crontab But the output of this command isn't very intuitive. ...
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119 views

Make cron inherit XDG_RUNTIME_DIR

I have a cron job that runs emacsclient which requires that XDG_RUNTIME_DIR to be set. I can set the variable to something like /run/user/1000 in the crontab but then this assumes that the owner of ...
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3 answers
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cron.service file not found

My backup script works fine when executed manually; but nothing runs from crontab. I am running Fedora 35 Workstation. The crontab editor works: $ crontab -e The cron daemon is not running. Each of ...
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3 answers
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What is the easiest way to run a program from time X to time Y?

There is a certain potentially failing process that I want to run until it succeeds, during the night time, say, from 23:00 to 7:00, but not later. A possible solution would be to: Add a cron job for ...
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What is the most efficient way to run a task every X hours of runtime, accumulated over all power-ons?

Let us assume that I have a machine which wakes up at 7:00, does some work, usually for 15 minutes, but sometimes for days (e.g., experiment supervision), and after the works is done, it powers ...
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Pass multiple directories to find in Mac for removing .DS_Store files

I have a defined list of directories that contain development code that I want to make sure that any .DS_Store files are never present, or removed shortly after being created. I will do this via ...
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