We say that the water is contained by a jar because we can easily
imagine water that's not contained by a jar. Can we have data "outside" of
a file? Does the mere recording of data instantiate a file if we ever hope
to find it again? (/dev/null is a distraction that will be ignored.)
Eve if we are using "file" in the broad, unixy sense (to include
executables, symbolic links etc) I still think we can have data which is
not a file. What about output? Are the commands sent by the ppp daemon
to my modem really files?