I just like to ask if anyone here knows how to automatically start a .sh program in Linux on a daily basis.
This is because I have a server running which runs untill a certain point at midnight then stops. I'd like to have a program that can automatically restart it at a certain time every day.
you can automatically run the script by using the cron deamon
First you have to add the command to cron
crontab -e //this will open a file with your default editor
//to this file add your command at last
command syntax:
* * * * * * /home/loc/shell.sh //runs every minuite
ex */45**** /home/loc/shllscript.sh // runs every 45 mins
cron will do what you need to do.
The first line will start your script at 2:30 every day. The second line will stop it at 12:00
30 2 * * * myscript.sh
00 12 * * * killall myscript.sh
you can also refer to "at", which can run jobs at certain time period
Related
I've setup a command like this:
protected function schedule(Schedule $schedule)
{
$schedule->command('feeds:fetch')->everyFiveMinutes();
}
I've setup a cron job to run php artisan schedule:run
When I run that line on dev's terminal it runs the task OK. On Prod it returns "No scheduled commands are ready to run."
Any way to troubleshoot this?
The fine folks at Larachat (https://larachat.slack.com/) helped me out debug this issue.
The problem was with my crontab. I was setting the crontab to execute the artisan scheduler as follows:
*/1 * * * * php /path/to/artisan schedule:run
(meaning execute every 1st minute of every hour every day.)
When it should be:
* * * * * php /path/to/artisan schedule:run
(meaning execute every minute of every hour every day.)
So, when I manually ran cron on a non-1st minute of every hour, it didn't run at all.
I have found a solution for this problem. Just add the timestamp in the $schedule.
You can change the command name, time and timezone according to your requirements.
$schedule->command('tenam:before')
->dailyAt('22:28')->timezone('Asia/Kolkata');
I've recently started a simple project, just to help me learn the BASH scripting language a little better. Anyway, this script is set to alternate/rotate the user's desktop background/wallpaper at a given interval.
Given that this task would most likely be done every 30 minutes to 1 hour, how should I go about doing this. Would 30 minute/1 hour timers be very inefficient? Or, could cronjobs do a better job for me?
Also, how could I get this script to run in the background, so that a terminal window is not always required to be open?
Could you provide some sort of an idea into the syntax, if you can, as well.
This would be a suitable job for cron. cron would take care of invoking the script at regular intervals. You would not then have to be concerned in your script when the script should run and managing a script running in the background.
Running in the background would be extravagent as the script does not need to do much - not much more than change the current desktop setting. Typically the script would only take a small fraction of a second to complete the task.
cron entries have six fields-:
mins hours day month day-of-week path_to_command
0-59 0-23 1-31 1-12 0-6 command
days of the week start on Sunday. 0=Sunday, 1=Monday etc.
cron entry to run the script every hour for all days and months-:
0 * * * * /path/change_wallpaper.sh
to list your current cron jobs, type
crontab -l
Edit your cron jobs and add the new cron entry-:
crontab -e
Check the new setting is in place -:
crontab -l
I would personally run the script using following crontab:
0 * * * * $HOME/changewallpaper.sh
which you can install as a user with this command
crontab -e
Other solutions include running daemon script from file ~/.xprofile
For more information please refer to
man crontab
man 5 crontab
Also check out this project Variety.
Also, how could I get this script to run in the background, so that a terminal window is not always required to be open?
That would be a daemon. And there's no need to write your own. It's a bit tedious in bash if you want pidfile, start|stop|restart etc. Just add a new cronjob which'll execute your script every n minute or something.
Edit your cronjobs
crontab -e
Execute script every 30 min: (not the same as 30, which would do it every hh:30!)
*/30 * * * * /path/to/your/script
Restart cron. How depends on distro, here's Ubuntu:
service cron restart
List cronjobs:
crontab -l
this is my first time writing script for cron job.
I wrote my code in shell, (which it works) and I'm trying to set it up for cron.
So here is my question. How do I set up the cron? Am I suppose to write
10 * * * * /home/workstation/deleter.sh (I want it to run every 10min)
right underneath #!/bin/sh? How would I execute it? (deleter.sh has permission via chmod)
man 1 crontab returns "No entry for crontab in section 1 of the manual"
I'm really lost and confused right now. If someone know how to set up cron please tell me!!
Thanks in advance
#!/bin/sh
counter=0
logloc=/home/ServerLogs
backup=/home/test
## Reads the location of the file systems that needs to be investigated from location.txt
## and save it into an array
while read -r line; do
Unix_Array[${counter}]=$line;
let counter=counter+1;
done < location.txt
## Reads Email recipients and save it into an array
More code continues from here......
The following will open your environment's text editor and load the crontab:
crontab -e
Your crontab entry is mostly correct. In order for your script to run every ten minutes it should be changed to:
*/10 * * * * /home/workstation/deleter.sh
The entry you indicated would run the script at the 10th minute of every hour.
To setup the cron, you can do one of two (main) things. The first would be to place the specified line in /etc/crontab. The second would be to run crontab -e and place the line in there. I would recommend to use crontab -e so the cron will execute as your own user account.
If the full path to the script is /home/workstation/deleter.sh and it does have execute-privileges, as you specified - your current line will have it execute 10-minutes past the hour, every hour. To get it to execute every 10 minutes, you'll have to use */10, like this:
*/10 * * * * /home/workstation/deleter.sh
this might help
http://www.manpagez.com/man/5/crontab/
you need to get an entry into your crontab
One of the best links I came across when I first learned about cron! Bookmark it
http://www.thegeekstuff.com/2009/06/15-practical-crontab-examples/
I am using ubuntu 12.04.I am using a script(./home/sam/code/imageUpdate) to synchronising images from server to a particular folder in local system. And I have to run the script in the evening always. So I want to write a crontab which will automatically runs the script.
My commands :
$crontab -e;
And added the scheduled time to the crontab file.
# 50 17 * * * cd /home/sam
# 52 17 * * * ./code/imageUpdate > image1.txt
Then I saved the file and waited for the result.
But I didn't get any result. No image was been synchronised to image1.txt file.
Have I left any step ?
Please help me out...
Thanks in advance.
Make sure you don't have hashes (comments) at the start of your crontab commands.
Additionally:
Crontab commands should be run in isolation.
Each crontab command will be run in its own context, changing directory in one instruction probably won't lead to that directory being sound for the next executed (they may be run in their own environments, e.g.).
To overcome this, write a simple shell script which encompasses all of your commands for a single action.
# MyCommand.sh
cd /home/sam
./code/imageUpdate > image1.txt
# crontab command
50 17 * * * /home/sam/MyCommand.sh
How to run a cron job in ubuntu in such a way that it should initiate a python script?
Please explain with a small example.
You can set a simple line to run from x to x time:
e.g.,
0,10,20,30,40,50 * * * * ~/py/my_python_script.py
runs every 10 minuts
STEP BY STEP USING VIM AS THE SELECTED EDITOR
At your terminal, run: sudo crontab -e
Afterwards, choose you favorite editor (e.g., vim)
type :i and hit enter to insert a new line
Past or write the cronjob line 0,10,20,30,40,50 * * * * ~/py/my_python_script.py and hit enter and then return to exit that line
type :w and hit enter, to write the file
type :q and hit enter to exit
Description for the asterisks:
minute (0-59), hour (0-23, 0 = midnight), day (1-31), month (1-12), weekday (0-6, 0 = Sunday), command
In-deep:
To read a more detailed process on how it all works:
CronHowto
VIM Commands Cheat Sheet
You can run Crontab in Ubuntu.
Simply just copy and paste the following script in the terminal.
crontab -e
There you can write command for run your python script, that will execute the program in a specific time interval.
* * * * * python </path/to/the/file>
You can refer the link for the time interval
You can check the log file here
tail -f /var/log/syslog