Question

I have a simple shell script whose also is below:

#!/usr/bin/sh

echo "starting the process which is a c++ process which does some database action for around 30 minutes"
#this below process should be run in the background
<binary name> <arg1> <arg2>

exit

Now what I want is to monitor and display the status information of the process.
I don’t want to go deep into its functionality. Since I know that the process will complete in 30 minutes, I want to show to the user that 3.3% is completed for every 1 min and also check whether the process is running in the background and finally if the process is completed I want to display that it is completed.

could anybody please help me?

Answer 1

The best thing you could do is to put some kind of instrumentation in your application,
and let it report the actual progress in terms of work items processed / total amount of work.

Failing that, you can indeed refer to the time that the thing has been running.

Here’s a sample of what I’ve used in the past. Works in ksh93 and bash.

#! /bin/ksh
set -u
prog_under_test="sleep"
args_for_prog=30

max=30 interval=1 n=0

main() {
    ($prog_under_test $args_for_prog) & pid=$! t0=$SECONDS

    while is_running $pid; do
        sleep $interval
        (( delta_t = SECONDS-t0 ))
        (( percent=100*delta_t/max ))
        report_progress $percent
    done
    echo
}

is_running() { (kill -0 ${1:?is_running: missing process ID}) 2>& -; }

function report_progress { typeset percent=$1
    printf "\r%5.1f %% complete (est.)  " $(( percent ))
}

main