sun
   microsystems              Systems Architecture Committee

_________________________________________________________________

Subject:       64-bit File Offsets

Submitted by:  Blake L.

File:          psarc/1991/004/opinion.ms

Date:          June 12th, 1991

Committee:     Bill S., Steve E., Rob G.,  Gra-
               ham  H., Marty H., Jarrett R.,
               Glenn Skinner, Rangaswamy V.

1.  Summary

The proposal describes an enhancement  to  several  internal
kernel  interfaces  and  data structures to allow for 64-bit
file offsets.  Also proposed is a new system call, llseek(),
and  use  of  the 64-bit offsets in the disk device drivers.
64-bit offsets would not be supported for  normal  files  at
this time.

2.  Decision & Precedence Information

The proposal was accepted as submitted.

The deliverable is classified as  minor.   The  incompatible
changes  proposed  affect  only  internal  kernel  (private)
interfaces.  The new llseek() system call  is  a  compatible
enhancement.

3.  Opinion

The committee finds the extensions acceptable.

It was agreed that the new llseek() system  call  should  be
added  to  the  standard  C library (libc).  This new system
call represents an extension to the  capabilities  of  other
libc functions and so most naturally belongs with them.

4.  Minority Opinion(s)

None.

5.  Advisory Information

The committee recognizes that the llseek() system call  will
likely  be  supplanted  by  some  standard  interface in the

psarc/1991/004         Copyright 1991 Sun Microsystems, Inc.

                           - 2 -

future.

6.  Appendices

6.1.  Appendix A: Technical Changes Required

None.

6.2.  Appendix B: Technical Changes Advised

None.

6.3.  Appendix C: Reference Material

     1.   ``64-bit  file  offset  proposal'',  Blake  Lewis,
          File: psarc/1991/004/91.06.25.spec.txt

psarc/1991/004         Copyright 1991 Sun Microsystems, Inc.