ref: 0ba323dbdbc78e4c6ccba79028997850d59b5bc6
dir: /bin/vol/
#!/bin/rc -e
rfork e
fn usage {>[1=2] echo 'usage:' $usage && exit 'usage'}
usage='vol [-+] | [+-]vol | vol'
fn expr {
op=$2
switch($op){
case [-+][0-9]*
echo $1 $op | bc
case - +
echo $1 $op $step | bc
case *
echo $2
}
}
if(~ $#* 0)
usage
step=5
vol=`{awk '/master/ {print $2, $3}' </dev/volume}
switch($#*){
case 1
vol=(`{expr $vol(1) $1})
case 2
vol=(`{expr $vol(1) $1} `{expr $vol(2) $2})
}
echo master $vol
echo master $vol >/dev/volume