#! /bin/bash
# progress-bar2.sh
# Author: Graham Ewart (with reformatting by ABS Guide author).
# Used in ABS Guide with permission (thanks!).

# Invoke this script with bash. It doesn't work with sh.

interval=1
long_interval=10

{
     trap "exit" SIGUSR1
     sleep $interval; sleep $interval
     while true
     do
       echo -n '.'     # Use dots.
       sleep $interval
     done; } &         # Start a progress bar as a background process.

pid=$!
trap "echo !; kill -USR1 $pid; wait $pid"  EXIT        # To handle ^C.

echo -n 'Long-running process '
sleep $long_interval
echo ' Finished!'

kill -USR1 $pid
wait $pid              # Stop the progress bar.
trap EXIT

exit $?