rmt(1M) 						  System Administration Commands						   rmt(1M)

NAME

       rmt - remote magtape protocol module

SYNOPSIS

       /usr/sbin/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(3SOCKET) or rcmd(3SOCKET) call.

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

       Anumber
     where number is an ASCII representation of a decimal number.

       Unsuccessful commands are responded to with:

       Eerror-number
error-message


	   where  error-number	is one of the possible error numbers described in intro(3), and error-message is the corresponding error string as
	   printed from a call to perror(3C).

	The protocol consists of the following commands:

       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).

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

       Ioperation
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.	When the operation is successful the return value is the count parameter.

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

       Odevice
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(9E). If a device is already open, it is closed before a new  open
				is performed.

       Rcount
 		Read count bytes of data from the open device. rmt performs the requested read(9E) and responds with Acount-read

				if the read was successful; otherwise an error in  standard format is returned. If the read  was  successful,  the
				data read is sent.

       Wcount
 		Write data onto the open device. rmt reads count bytes from the connection, aborting if a premature EOF is encoun-
				tered. The response value is returned from the write(9E) call.

       Any other command causes rmt to exit.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWrcmdc 		   |
       +-----------------------------+-----------------------------+

SEE ALSO

       ufsdump(1M), ufsrestore(1M), intro(3), ioctl(2), lseek(2), perror(3C), rcmd(3SOCKET), rexec(3SOCKET), attributes(5),  mtio(7I),  open(9E),
       read(9E), write(9E)

DIAGNOSTICS

       All responses are of the form described above.

BUGS

       Do not use this for a remote file access protocol.

SunOS 5.11							    6 Nov 2000								   rmt(1M)