Unix undelete?

[Guy Harris]

>It would in theory be possible for Unix to implement an undelete by
>placing deleted I-nodes on some kind of a holding queue, and then
>destroying the I-nodes and reclaiming the space in queue order
>only when the space is actually needed for new files.

Sounds sort of like what the "undelete" in the Norton Utilities for UNIX
does....

(As I understand it, they add a new file system type that intercepts
some calls that destroy data - specifically, those that remove files or
truncate them to zero length - and that, instead, shoves the file's
contents into another file in a hidden directory, presumably not by
copying it but by assigning the blocks and file map to another file.)

I don't think it exists yet for IRIX; the first implementation was for
System V/386.  I think SunOS and some other versions are in the
pipeline.