Progress bar script

How to make a progress bar for bash command

run_command_progress()
{
    local n=0
    local steps=$2
    local progress_bar=""
    local counter=0
    local files=0

    ECHO "run_command_progress: '$1'" 
    [ -z "$steps" ] && { steps=1; }

    [ -n "$3" ] && [ -d "$3" ] && { steps=`find $3 | wc -l`; steps=`expr $steps / 50`; }

    eval $1 | while read line
    do
        #((n++))
        #((files++))
        ((++n))
        ((++files))

        if [ $n -ge $steps ] ;
        then
            #((counter++))
            ((++counter))
            if [ $counter -le 50 ] ;
            then
                progress_bar="$progress_bar#";
                printf "     --------------------------------------------------|\r[%03d]$progress_bar\r" $steps
            else
                printf "[%03d#$progress_bar|\r" `expr $files / 50`
            fi

            n=0
        fi
    done

    echo ""
}