I would like to have a cron job which executes 3 shell scripts consecutively i.e., execution of next shell script depending on the completion of previous scripts.
How can I do it?
Here is an example showing a cron which executes 3 scripts at 9am Mon-Fri.
00 09 * * 1-5 script1.sh && script2.sh && script3.sh 2>&1 >> /var/tmp/cron.log
If any one of the scripts fails, the next script in the sequence will not be executed.
Write one script which calls these three scripts and pit it into cron.
To elaborate on yi_H's answer: You can combine them in one shell script in different ways, depending on what you want.
job1.sh
job2.sh
job3.sh
will run all three consecutively, regardless of the result.
job1.sh && job2.sh && job3.sh
will run all three, but it will stop if one of them fails (that is, if job1 returns an error, job2 and job3 will not run).
Related
I want to submit an R script myjob.R that takes two arguments for which I have several scenarios (here only a few as an example).
I want to pass these arguments by looping through scens and sets.
In order to avoid overloading the squeue on the cluster, I don't want to submit the whole loop at once.
Instead I want to wait 1h between each individual job submission.
Therefore, I included the sleep 1h command, after each iteration.
I used to launch the bash script via bash mybash.sh, however this command requires to keep the terminal open until all jobs have been submitted.
My solution was then to launch mybash.sh via sbatch mybash.sh. This is somehow nesting two sbatch commands. Seems to work very well.
My question is only if there is any reason against submitting nested sbatch commands.
Thanks!
Here is mybash.sh script:
#!/bin/bash
scens=('AAA' 'BBB')
sets=('set1' 'set2')
wd=/projects/workdir
for sc in "${!scens[#]}";do
for se in "${!sets[#]}" ;do
echo "SCENARIO: ${scens[sc]} --- SET: ${sets[se]}"
sbatch -t 00:05:00 -J myjob --workdir=${wd} -e myjob.err -o myjob.out R --file=myjob.R --args "${scens[sc]}" "${sets[se]}"
# My solution is to include the following line & run this bash script via sbatch
sleep 1h
done
done
In my app I've got one task that needs to be done every 48 hours on server side. I've created a console command in order to automatize my job. However I don't know how can I set timer to keep invoking that command. Can you point my a way to do that?
You should see on a cron commands.
Cron will run your command every X (frequency) times.
TO create a cron, (on unix) use: crontab -e
For example
0 0 */2 * * bin/console app:command >/dev/null 2>&1
will run every odd days, bin/console app:command
to help you generating a cron
https://crontab-generator.org/
How are the executed, if two jobs schedules in same cron line: parallely or sequentially?
e.g:
0 3 * * * ./fillers.sh > /dev/null 2>&1; ./pionner.sh > /dev/null 2>&1;
Strictly speaking, that's one job, not two. The command is passed to /bin/sh to be executed. The two sub-commands are executed sequentially, jus as if you had typed the same command at a shell prompt.
If you want them executed in parallel, use an & after the first sub-command rather than a ;.
I am not able to understand the answer for this question: "What's the difference between cron and crontab." Are they both schedulers with one executing the files once and the other executing the files on a regular interval OR does cron schedule a job and crontab stores them in a table or file for execution?
Wiki page for Cron mentions :
Cron is driven by a crontab (cron table) file, a configuration file
that specifies shell commands to run periodically on a given schedule.
But wiki.dreamhost for crontab mentiones :
The crontab command, found in Unix and Unix-like operating systems, is
used to schedule commands to be executed periodically. It reads a
series of commands from standard input and collects them into a file
known as a "crontab" which is later read and whose instructions are
carried out.
Specifically, When I schedule a job to be repeated : (Quoting from wiki)
1 0 * * * printf > /var/log/apache/error_log
or executing a job only once
at -f myScripts/call_show_fn.sh 1:55 2014-10-14
Am I doing a cron function in both the commands which is pushed in crontab OR is the first one a crontab and the second a cron function?
cron is the general name for the service that runs scheduled actions. crond is the name of the daemon that runs in the background and reads crontab files. A crontab is a file containing jobs in the format
minute hour day-of-month month day-of-week command
crontabs are normally stored by the system in /var/spool/<username>/crontab. These files are not meant to be edited directly. You can use the crontab command to invoke a text editor (what you have defined for the EDITOR env variable) to modify a crontab file.
There are various implementations of cron. Commonly there will be per-user crontab files (accessed with the command crontab -e) as well as system crontabs in /etc/cron.daily, /etc/cron.hourly, etc.
In your first example you are scheduling a job via a crontab. In your second example you're using the at command to queue a job for later execution.
I want to run a Unix command (e.g. ls) at 5 minute intervals through a script.
Explanation:
I have a Unix script. In that script I have a command called "ls".
I want that "ls" command to run every 5 minutes from that script.
Use watch. The -n flag specifies interval in seconds, so
watch -n 300 ls
while true; do
ls
sleep 300
done
?
Put your script into the Crontab via
crontab -e
More information about Cron you can find at wikipedia
You could use crontab for example. See http://en.wikipedia.org/wiki/Cron
for example i you want to run your script every five minutes via crontab it should look something like this:
#m h dom mon dow user command
*/5 * * * * root /path/to/script
crontab
http://en.wikipedia.org/wiki/Cron
or
svc
http://cr.yp.to/daemontools.html