Overwrites the last line of the terminal

overwrite.sh

# Outputs without a newline and overwrites anything that was already on the last line of
# the terminal
overwrite ()
{
        output="$1"
        if [ -z "$output" ]
        then
                read output
        fi
        printf "\r"
        if [ -n "$LAST_OVERWRITE_LENGTH" ]
        then
                if [ "$LAST_OVERWRITE_LENGTH" -gt 0 ]
                then
                        clear_space_count=0
                        while [ $clear_space_count -lt $LAST_OVERWRITE_LENGTH ]
                        do
                                printf " "
                                let clear_space_count++
                        done
                        printf "\r"
                fi
        fi
        # only save length of last line
        while read -r line
        do
                LAST_OVERWRITE_LENGTH=${#line}
                printf "$line"
        done <<< "$output"
}

# Outputs with a newline and overwrites anything that was already on the last line of
# the terminal
overwriteln ()
{
        overwrite "$@"
        printf "\n"
        LAST_OVERWRITE_LENGTH=0
}