A quick /etc/rmt question

[Dave Cornutt]

In article <886 at srs.UUCP> srs!dan at cs.rochester.edu (Dan Kegel) writes:
 > I'm trying to manipulate a remote tape drive from within a program, and 
 > /etc/rmt looks like just the ticket.  Unfortunately, I can't get it to
 > work even from the shell.  Here's what I tried:
 > 
 >     % ls -l /dev/rmt8
 >     crw-rw-rw-  1 root      30,   8 May 24 14:18 /dev/rmt8
 >     % /etc/rmt
 >     O /dev/rmt8 2			# command to open a device for r/w
 >     					# extra newline to get the reply?
 >     E2					# reply from /etc/rmt: ENOENT
 >     No such file or directory
 >     %
 > What am I doing wrong?  Thanks for any (preferably e-mailed) replies.

I thought that this might be of general interest, so I'm posting it.

I have done this with the /etc/rmt that comes with Sun 3.4, which I
assume is the BSD 4.2 one.  The documentation is wrong; it leads
you to believe that arguments are separated by spaces, but this is
not the case.  The first argument is flush against the command letter
(no space), and subsequent args, if any, are separated by newlines.
So, it should look like this:

% /etc/rmt
O/dev/rmt8
2
A0

Note that: (1) there is no space between the O and the slash, and
(2) the A0 is the acknowledgement (the count is not significant
for open).

If you need more help, drop me a line.  I've written an /etc/rmt
for Vax S5R2 (paging).  It can't emulate all of the functions,
but it does enough of them so that I can dump from my 3/180
to one of the S5 Vaxen.

The BSD 4.3 one I think is the same, because I used to do dumps
from Suns to a Gould PN9000 running UTX 2.0, which is 4.3-based.

-- 
Dave Cornutt, AT&T Bell Labs (rm 4A406,x1088), Holmdel, NJ
UUCP:{ihnp4,allegra,cbosgd}!hotly!dkc
"The opinions expressed herein are not necessarily my employer's, not
necessarily mine, and probably not necessary"