progressbar in bash for anything

progressbar.sh

#!/bin/bash
# could be placed in a single line
A=$1; # change to something with a number, first script's arg
B=$((A*40/$2)); # calculates the portion in a progress bar of 40 # where $2 is the total as 2nd script's arg
C=$((40-B)); # left
B=$(printf "%${B}s");
C=$(printf "%${C}s");
printf "\r[${B// /#}${C// /-}] $A%%\n" $A;

the result:
[########################----------------] 61%