Tracking the executing time of a process.

The command "ps" is used to list the processes running in the system and by adding various options to it we can get different informations regarding a process.
To find the time from which a proces has been executing we can use the option etime i.e.

ps -eo cmd,pid,etime.
For example, let us createa bash script that will run for 60 seconds

script.sh #!/bin/bash sleep 60

save it and give it execute permissions.

chmod 777 script.sh

Execute it and put it in the back ground.

./script.sh &

Now use the command ps to find the running time of the script.

ps -eo cmd,pid,etime | grep script bash script 3506 00:16 grep script 3509 00:00

We can see in the last column that process "script" has been running from 16 seconds.
If we execute ps again after a few secods we can see the change in the value.

ps -eo cmd,pid,etime | grep script bash script 3506 00:45 grep script 3509 00:00

Thus we can track the execution times of processes using ps.