path: libfiu_1.2-5/doc/posix.rst
works again::
  $ fiu-ctrl -c "disable name=posix/io/oc/open" `pidof top`
And everything should have gone back to normal.


path: libfiu_1.2-5/doc/posix.rst
fail unconditionally::
  $ fiu-ctrl -c "enable name=posix/io/oc/open" `pidof top`
After that moment, the top display will probably be empty, because it can't