reading a pipe/device ie: to be able to use XFS snaphots

as in v4 we cat a dumps to tmp file like /Users/tom/Backup/.tmp. The idea here is to avoid the using a tmp path, as the data may already exist in a form of filesystem snapshot? or it may come from a pipe? or a device?.

it would require to change run some "pre" tasks to create snapshot, mount device etc. and then only read from this pipe/device instead of from /Users/tom/Backup/.tmp/xyz.