You should be able to display an existing DU dump; think xdu or xdiskusage. That automatically buys you features like one FS, yes or no counting hard links, s

You should be able to display an existing DU dump; think xdu or xdiskusage. That automatically buys you features like one FS, yes or no counting hard links, soft links, all sorts of exclusion nuances... Your neat feature is a display; don't hobble it by strapping it to a slapdash scanner.