Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!xanth!ukma!rutgers!att!chinet!les
From: les@chinet.chi.il.us (Leslie Mikesell)
Newsgroups: comp.unix.wizards
Subject: Re: GNU-tar vs dump(1)
Message-ID: <7479@chinet.chi.il.us>
Date: 18 Jan 89 04:39:05 GMT
References: <17999@adm.BRL.MIL> <629@mks.UUCP> <11@estinc.UUCP> <10797@rpp386.Dallas.TX.US> <1966@netmbx.UUCP> <6099@polya.Stanford.EDU> <848@auspex.UUCP>
Reply-To: les@chinet.chi.il.us (Leslie Mikesell)
Organization: Chinet - Public Access Unix
Lines: 17

In article <848@auspex.UUCP> guy@auspex.UUCP (Guy Harris) writes:
>Not without changing "tar" to do an "fstat" before it starts reading to
>get the current accessed time, and an "fstat" to get the current
>modified time and a "utime(s)" call to set the accessed time to its old
>value (and set the modified time to its current value - you have to
>change both) after it finishes reading.

Cpio has the -a flag to do this and it is (unfortunately) on in the
sysadmin scripts on the AT&T 3B2's.  The problem is that resetting the
atime sets the ctime to the current time.  Then if you try to do a
sensible backup based on ctime you can't do it.  This has been a real
problem once or twice because the network DOS server uses the client
PC's time to set the mtime on files.  So, with the PC clock set wrong
and a sysadmin backup made there is no way to find the real date of
a file.

Les Mikesell