ref: f78033a99ecf9e539207ad1c4e8d5a0188d9a56f
dir: /rc/bin/dircp/
#!/bin/rc
# dircp src dest - copy a tree with tar
switch($#*){
case 2
@ {builtin cd $1 && tar cif /fd/1 .} | @ {builtin cd $2 && tar xTf /fd/0}
case *
echo usage: dircp from to >[1=2]
exit usage
}