# Get controlling terminal

getctty()
{
    abbr=$(ps o pid,tt | sed -n -E 's/^ *'$$' +([^ ]+) *$/\1/p')
    [ -n "$abbr" ] || { echo "Can't get controlling terminal" >&2; return 1; }
    ctty="/dev/tty$abbr"
    return 0
}
.