Preservation of correspondence

[Jules Richardson]

der Mouse wrote:
>> I really need to find the time to write a Linux util to suck tar data
>> off DLT and checksum file-by-file to test backups; currently I
>> restore the whole archive and then use find/cksum/diff to check
>> against source data, but it's annoying needing that extra disk
>> capacity just for the sake of backup testing.
> 
> I wrote my own version of tar, which among other things has a mode in
> which it reads a tape as if to restore, but, instead of restoring, it
> compares what it finds on the tape with what it finds in the
> filesystem.

Well I *think* that's what the diff/compare option is supposed to do (or maybe 
  W/verify, can't remember which), but unfortunately short of looking in the 
source code itself I couldn't find any documentation on exactly how the 
comparison is done (and quite possibly it differs between tar implementations 
anyway). In theory it *should* be a byte-for-byte comparison, but unless the 
docs say so we don't know that for sure...

> It may well turn out to be not what you want, but it might be worth at
> least a look-in.  If it seems close but not quite there, I'll be happy
> to correspond about it 

Do you happen to know if GNU tar adds extensions that aren't in your version 
(or "original tar", whatever that may mean)? I suppose I'd like to stick to 
GNU or GNU-compatible tools where possible...

 > (though in your case it might be a bit, um,
> interesting, since it appears you use both Yahoo for your email and are
> in the UK).

Well I'm in the US at the moment ;)  If anyone has any suggestions for good 
ISP-independent email services then let me know; the reason I've used yahoo 
for years is so that I don't get tied to a single ISP for receiving email, but 
there are doubtless better offerings around...

cheers

Jules