Simulating a spinner for progress in Bash

Question

I am currently learning how to make scripts a bit more verbose. The below code shows a spinner. However, I am having difficulties modifying this spinner to have the words such as 'Downloading'. I want both the words and spinner to appear beside each other. I am not asking how to implement spinner for progress but how to concatenate with words. How could achieve this goal?

sp='/-\|'
sc=0
spin() {
   printf "\b${sp:sc++:1}"
   ((sc==${#sp})) && sc=0
}
endspin() {
   printf "\r%s\n" "$@"
}

until work_done; do
   spin
   some_work ...
done
endspin

Answer 1

While I admire the DIY spirit of Ed and Jakuje I also like to reuse other folks code. If you'd rather recycle than recreate consider Louis Marascio's spinner. I put his spinner() function into my shell library and it is easy to use:

#!/bin/bash

. lib.sh
run_10s &
echo -n wait
spinner $!
echo -e "\rdone"

displays

$ ./test_lib
wait [/]

for 10 seconds with the spinner spinning and then it clears that line left containing wait with the \r and you are left with just

$ ./test_lib
done

on the screen.