RMT(8N)                 COMMAND REFERENCE                 RMT(8N)



NAME
     rmt - remote magtape protocol module

SYNOPSIS
     /etc/rmt

DESCRIPTION
     Rmt is a program used by the remote dump and restore
     programs in manipulating a magnetic tape drive through an
     interprocess communication connection.  Rmt is normally
     started up with an rexec(3n) or rcmd(3n) call.

     The rmt program accepts requests specific to the
     manipulation of magnetic tapes, performs the commands, then
     responds with a status indication.  All responses are in
     ASCII and in one of two forms.  Successful commands have
     responses of

          Anumber\n

     where number is an ASCII representation of a decimal number.
     Unsuccessful commands are responded to with

          Eerror-number\nerror-message\n,

     where error-number is one of the possible error numbers
     described in intro(2) and error-message is the corresponding
     error string as printed from a call to perror(3c).  The
     protocol is comprised of the following commands (a space is
     present between each token).

     O device mode
                Open the specified device using the indicated
                mode.  Device is a full pathname and mode is an
                ASCII representation of a decimal number suitable
                for passing to open(2).  If a device had already
                been opened, it is closed before a new open is
                performed.

     C device   Close the currently open device.  The device
                specified is ignored.

     L whence offset
                Perform an lseek(2) operation using the specified
                parameters.  The response value is that returned
                from the lseek call.

     W count    Write data onto the open device.  Rmt reads count
                bytes from the connection, aborting if a
                premature end-of-file is encountered.  The
                response value is that returned from the write(2)
                call.



Printed 4/6/89                                                  1

RMT(8N)                 COMMAND REFERENCE                 RMT(8N)



     R count    Read count bytes of data from the open device.
                If count exceeds the size of the data buffer (10
                kilobytes), it is truncated to the data buffer
                size.  Rmt then performs the requested read(2)
                and responds with Acount-read\n if the read was
                successful; otherwise an error in the standard
                format is returned.  If the read was successful,
                the data read is then sent.

     I operation count
                Perform a MTIOCOP ioctl(2) command using the
                specified parameters.  The parameters are
                interpreted as the ASCII representations of the
                decimal values to place in the mt_op and mt_count
                fields of the structure used in the ioctl call.
                The return value is the count parameter when the
                operation is successful.

     S          Return the status of the open device, as obtained
                with a MTIOCGET ioctl call.  If the operation was
                successful, an ack is sent with the size of the
                status buffer, then the status buffer is sent (in
                binary).

     Any other command causes rmt to exit.

DIAGNOSTICS
     All responses are of the form described above.

RETURN VALUE
     [0]        Rmt was successful.

     [1]        Rmt was unsuccessful.

CAVEATS
     People tempted to use this for a remote file access protocol
     are discouraged.

SEE ALSO
     rcmd(3n), rexec(3n), rdump(8n), and rrestore(8n).















Printed 4/6/89                                                  2

%%index%%
na:240,88;
sy:328,184;
de:512,2576;3400,1498;
di:4898,175;
rv:5073,259;
ca:5332,167;
se:5499,206;
%%index%%000000000131