GNU-tar vs dump(1)

Leslie Mikesell les at chinet.chi.il.us
Wed Jan 18 14:39:05 AEST 1989


In article <848 at auspex.UUCP> guy at 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



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