How to check the execution time of your bash script?

Do you have a long running bash script on your server’s cron list? And you really wanna get notified about the total execution time for your cron?

Yeah, here we go! We can not find out the total execution time from the cron log. We can use bash variables to find out the total execution time.

However, you can check the cron execution status from the log /var/log/cron. One of my friends asked me about this question. He wanted to find out the total execution time of his cron job.

I did some search on Google and found out a solution by using SECONDS builtin variable available in Linux Bash. It tracks the number of seconds that have passed since the shell was started.

You need to set this variable 0, before starting the script. The value returned after some work is equal to the sum of assigned value (here 0) and the total time spend just before we called the SECONDS variable again.

I am using the “seq” command to generate a sequence and save it to a file. And we can check the time for cron execution using SECONDS builtin variable.

The sample code in a cron is pasted below:

File : /root/diff2.sh

#!/bin/sh
echo " " > /root/time.txt
echo "Start time is: " $(date +%T) >> /root/time.txt
SECONDS=0
seq 100000000 > /root/seq.txt
echo "End time is: " $(date +%T) >> /root/time.txt
duration=$SECONDS
echo "Total time spend is pasted below:"
echo "$(($duration / 60)) minutes and $(($duration % 60)) seconds elapsed." >> /root/time.txt

Cron sample:

[root@connect ~]# crontab -l
*/5 * * * * /bin/sh /root/diff2.sh

See the output here:

[root@connect ~]# cat /root/time.txt

Start time is:  20:20:01
End time is:  20:21:16
Total time spend is pasted below:
1 minutes and 15 seconds elapsed.

One more

[root@connect ~]# cat /root/time.txt

Start time is:  00:30:01
End time is:  00:31:16
Total time spend is pasted below:
1 minutes and 15 seconds elapsed.

If you wish, you can set email alert for this cron.

There are many other options available to check the total time spend for a script. Please comment here, if you get a quick way than the one mentioned here 🙂

Please try it and let me know if you have any questions. Thanks for your time!!

Read also:

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