Alex Whites solution to end of tape recognition in UNIX
ron%b...@sri-unix.uucp
ANSI Labels? Now theres something that isn't compatible with the UNIX
spirit. Files are files. Just bytes. Who needs records and labels.
-Ron
Guy Harris
> spirit. Files are files. Just bytes. Who needs records and labels.
The same argument could be levelled agains "tar" or "tp" or "cpio"-format
tapes. Labels are needed to indicate the name of the file which follows
the label. ANSI labelled tapes need not have files divided into records;
RT-11 happily writes a stream of bytes (or blocks, if you prefer) after the
label. ANSI labelled tapes as a UNIX storage medium should be considered
to be the same sort of thing as "tar" or "cpio" tapes; the labels are there
for the benefit of the tape reading program, and the structure of the
data is the business of the program for whom the files are intended, not
the tape reading program.
It might be useful, however, to have a program which understands the
ANSI *record* format as well; this could be used to transfer files (source-type
files, anyway) between various machines, including machines running UNIX.
I agree that OS support of labelled tapes might not be useful; however, the
cheap answer to the question of "who needs records and labels" is "people
who have to read or write tapes which are compatible with systems which
use ANSI labelled tapes". UNIX doesn't exist in a vacuum; there *are* other
systems out there and UNIX *does* have to deal with them.
Guy Harris
{seismo,ihnp4,allegra}!rlgvax!guy