Show elapsed time every second running a bash script

Question

I'm running a shell script in Linux Mint that calls some processes taking few minutes. For each process I want to echo a message like this:

echo "Cleaning temporary files... X seconds."
myprocess

where X is the current elapsed time and I would like it to change every second, but not printing a new line.

Is there a good way to do that? I only found ways to print the total time in the end, but not the elapsed time while running the process.

Answer 1

Use this at the beginning of your script, this creates a subprocess which runs in background and keeps on updating the status.

file=$(mktemp)
progress() {
  pc=0;
  while [ -e $file ]
    do
      echo -ne "$pc sec\033[0K\r"
      sleep 1
      ((pc++))
    done
}
progress &
#Do all the necessary staff

#now when everything is done
rm -f $file

Answer 2

You can run each command with time:

time <command>

and then use sed/awk to exctract the elapsed time.