read(2) won't move TK50 past tape file mark
George Robbins
grr at cbmvax.UUCP
Thu May 25 13:21:48 AEST 1989
In article <2721 at helios.ee.lbl.gov> envbvs at epb2.lbl.gov (Brian V. Smith) writes:
> According to the manual entry for mtio(4) on Ultrix 3.0
> (quoted w/o permission):
>
> done with a tape ioctl call. A zero byte count is returned
> when a tape mark is read, but another read will fetch the
> first record of the next tape file. When a file open for
> writing is closed, two end-of-files (EOF) are written.
And the tape is repositioned after the first of
the two tape marks...
> Therefore, you could expect to get 0 bytes read for two reads
> (because of two possible EOF's on the tape), but after that it should
> read the next file.
No, the bug is most likely that the Ultrix driver *is* playing
the sticky EOF game. If the program closed/opened the input file
it would probably work fine, though the man pages imply this is
not necessary.
--
George Robbins - now working for, uucp: {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing arpa: cbmvax!grr at uunet.uu.net
Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)
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