SunOS 3.5 dd (ibs == obs) != bs

[mcneill]

In using dd in a pipe such as:

   rsh otherhost "tar cbf 512 - ." | dd bs=262144 of=/dev/rst9

I noticed that this does not work, but:

   rsh otherhost "tar cbf 512 - ." | dd obs=262144 ibs=262144 of=/dev/rst9

works just fine.  I looked at the System V source for dd and saw something 
like:

   if (bs) ibs = obs = bs;

which leads me to believe that setting bs should do the same thing as 
setting both ibs & obs.

Does BSD do something different which makes this feature or did I miss
something in the source.


-- 
    Keith D. McNeill              |    E.I. du Pont de Nemours & Co.
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