ref: cd01b5e9ec73d404dd04ab62b652ca068e2ed835
dir: /rc/bin/chdev/
#!/bin/rc
rfork e
fn usage {
	echo 'usage:' $0 '[ -nr ] devmask' >[1=2]
	exit usage
}
op='&'
while(~ $1 -*){
	switch($1){
	case -n; op='~'
	case -r; op='&~'
	case *; usage
	}
	shift
}
echo chdev $op $1 >> '#c/drivers'