Path: utzoo!attcan!uunet!husc6!rutgers!att!ttrdc!levy
From: levy@ttrdc.UUCP (Daniel R. Levy)
Newsgroups: comp.unix.wizards
Subject: /etc/rmt on suns -- does it work?  Having trouble, TFM doesn't help
Message-ID: <3274@ttrdc.UUCP>
Date: 18 Mar 89 03:56:26 GMT
Lines: 47

Unix-Gurus of the net, HALLLLLLLLLLP!!!!

I have made the apparent mistake of believing the SUN manpage rmt(8C) for
/etc/rmt, the remote magtape daemon.  According to the documentation, as I
read it, I should be able to start /etc/rmt and feed it commands and data, and
expect acknowledgments and data back from it.  Well, that doesn't seem to work
very well (read: at ALL).  I tried it locally (that shouldn't matter, should
it?)  and here's what happens with a tape, write protect turned off (i.e.
writeable), in drive /dev/rst0, on a SUN4 under SunOS 4.0:

skfe$ ls -l /dev/rst0
crw-rw-rw-  1 root      18,   0 Aug 31 1988 /dev/rst0
skfe$ echo TEST | dd conv=sync of=/dev/rst0
0+1 records in
1+0 records out
skfe$ dd if=/dev/rst0
TEST
1+0 records in
1+0 records out
skfe$ /etc/rmt
O /dev/rst0 438 [me -- note that 438 decimal is 0666 octal]
R 512 [me -- try to read a record]
E2 [from /etc/rmt]
No such file or directory [from /etc/rmt]
S [me -- try to get tape status]
E9 [from /etc/rmt]
Bad file number [from /etc/rmt]
skfe$ echo $?
3

The manpage doesn't say what input commands are supposed to be terminated
with; I am assuming newline since the returned acknowledgment/error commands
are also thus terminated.  I tried null, and then I tried space, instead;
neither elicited any output from /etc/rmt at all.  I get the same behavior
on a Sun-3 under SunOS 3.5 as I did above.

At this point I'm up a (binary) tree.  Does /etc/rmt really WORK, and what
should I send it to make it work?  Does it require arguments?  (I found that
if I gave it an argument, it would create an empty file of the same name as
the argument -- weird?!?)

Thanks mucho in advance-o!
-- 
Daniel R. Levy             UNIX(R) mail:  att!ttbcad!levy
AT&T Bell Laboratories
5555 West Touhy Avenue     Any opinions expressed in the message above are
Skokie, Illinois  60077    mine, and not necessarily AT&T's.