writes zeros on the 32 bytes occupied by the i-node
argument is given, the i-node resides on
the given device, otherwise on a
name referring to a device
containing a file system.
will show up as ``missing'' in a
Read and write permission is required on the specified
The i-node becomes allocatable.
The primary purpose of this routine
is to remove a file which
for some reason appears in no
If it is used to zap an i-node
which does appear in a directory, care should be taken to track down
Otherwise, when the i-node is reallocated to some new file,
the old entry will still point to that file.
At that point removing the old entry will destroy the new file.
The new entry will again point to an unallocated i-node,
so the whole cycle is likely to be repeated again and again.
Whatever the default file system is,
it is likely to be wrong.
Specify the file system explicitly.
is likely to be ineffective.