readv(), writev()

[Rick Genter]

     Can someone explain why readv()/writev() are system calls?  As far as I
can tell the only advantage to having them be syscalls is to prevent the user
from having to either a) issue multiple read() calls or b) allocate twice as
much buffer space and use bcopy().  Is there another reason?
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Rick Genter 				BBN Laboratories Inc.
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rgenter at labs-b.bbn.COM  (Internet new)	Cambridge, MA   02238
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