On 09Mar2007 17:51, Les Mikesell <lesmikesell@xxxxxxxxx> wrote:
| Cameron Simpson wrote:
| >I have also thought of a much simpler way to solve your problem.
| >The trailer record is the source of all our pain. Write a small perl or
| >python or C program that seeks to the end of stdout minus the length of
| >the trailer record then execs a "tar cf - ..." for you. Thus:
|
| It's been ages since I looked at the tar source but I could have sworn
| it tried to do that itself if it could seek on the media.
Well it _should_ in append/update mode, but Mike McCarty's tests seem to
show that GNU tar is doing something obscenely expensive in these modes,
not merely backing over the trailer and appending. I imagine it's doing
some table of contents rationalisation or such. I would have imagined
that the --concatenate ("A") mode would just backspace over the trailer
and append, but it seems not.
hence the hack.
--
Cameron Simpson <cs@xxxxxxxxxx> DoD#743
http://www.cskk.ezoshosting.com/cs/
You try and make the place as secure as you can, but you don't reckon
with the kind of people who try and break into an explosives factory
with an oxy-acetylene torch.
