clri.8

UNIX v6源代码 这几乎是最经典的unix版本 unix操作系统设计和莱昂氏unix源代码分析都是用的该版

.th CLRI VIII 10/31/73
.sh NAME
clri \*- clear i-node
.sh SYNOPSIS
.bd clri
i-number [ filesystem ]
.sh DESCRIPTION
.it Clri
writes zeros on the 32 bytes occupied by the i-node
numbered
.it i-number.
If the
.it "file system"
argument is given, the i-node resides on
the given device, otherwise on a
default file system.
The file system argument
must be a special file
name referring to a device
containing a file system.
After
.it clri,
any blocks
in the affected file
will show up as ``missing'' in an
.it icheck
of
of the file system.
.s3
Read and write permission is required on the specified
file system device.
The i-node becomes allocatable.
.s3
The primary purpose of this routine
is to remove a file which
for some reason appears in no
directory.
If it is used to zap an i-node
which does appear in a directory, care should be taken to track down
the entry and remove it.
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.
.sh BUGS
Whatever the default file system is,
it is likely to be wrong.
Specify the file system explicitly.
.s3
If the file is open,
.it clri
is likely to be ineffective.