Subject: Re: atime mtime ctime
To: Aaron J. Grier <agrier@poofygoof.com>
From: Robert Elz <kre@munnari.OZ.AU>
List: netbsd-users
Date: 11/22/2000 15:25:48
    Date:        Tue, 21 Nov 2000 23:03:25 -0800
    From:        "Aaron J. Grier" <agrier@poofygoof.com>
    Message-ID:  <20001121230325.G578@goldberry.poofy.goof.com>

  | just a silly unix question:  why do files under the common unix
  | filesystems (ffs, ufs, et al) have atime, ctime, and mtime, but no
  | creation time?

Aside from "it has always been that way", ask yourself just
what "creation time" really means, can you actually define it
in any sensible way?

All the systems that I have ever seen that had the concept of
"creation time" defined it in some meaningless and arbitrary
way that really meant that the thing is useless.

Eg:  consider

	rm -f abc
	cat <file >abc
	cp abc def
	cp def abc
	rm abc
	cp def abc
	cat < def > abc
	rm abc
	cat < def > abc
	ed abc <<!
	w
	q
	!
	othered abc  (do the same commands, in this editor the
			old abc is renamed, and a new one created)
	ci abc
	rm -f abc
	co abc

	ln abc ghi
	rm -f abc
	mv ghi abc

	ln abc ghi
	rm -f abc
	cp ghi abc
	rm ghi

	mv abc ghi
	ln ghi abc
	rm ghi

	cat < file > abc

Go through all of that, and more like it, and decide which of the
commands set the creation time of abc, and which do not, and then
justify the result for any practical use whatever.

kre