rmt(1M) 																   rmt(1M)

NAME

       rmt - remote magnetic-tape protocol module

SYNOPSIS

DESCRIPTION

       is  a  program  used  by  the remote dump and restore programs for manipulating a magnetic tape drive through an interprocess communication
       (IPC) connection.  The and commands also use to achieve remote backup capability (see fbackup(1M) and frecover(1M)).  is  normally  started
       up with an or call (see rexec(3N) and rcmd(3N)).

       accepts	requests  specific  to	the  manipulation  of  magnetic tapes, performs the commands, then responds with a status indication.  DDS
       devices that emulate magnetic tapes are also supported.	All responses are in ASCII and in one of  two  forms.	Successful  commands  have
       responses of

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

       where  error-number  is	one  of  the  possible	error numbers described in errno(2) and error-message is the corresponding error string as
       printed from a call to (see perror(3C)).  The protocol is comprised of the following commands:

	      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 (see open(2)).  If a device is already open, it is closed before a new open is
				   performed.

	      Open the specified   device using the indicated mode.  device is a full pathname and mode is an ASCII  representation  of  an  octal
				   number suitable for passing to If a device is already open, it is closed before a new open is performed.

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

	      Perform an	   operation using the specified parameters (see lseek(2)).  The response value is that returned from by

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

	      Read		   count bytes of data from the open device.  If count exceeds the size of the data  buffer  (10  Kbytes),  it	is
				   truncated  to  the data buffer size.  then performs the requested and responds with if the read was successful.
				   Otherwise an error is returned in the standard format.  If the read was successful, the data read is then sent.

	      Perform a 	   command using the specified parameters.  Parameters are interpreted as ASCII  representations  of  the  decimal
				   values to be placed in the and fields of the structure used in the call.  The return value is the count parame-
				   ter when the operation is successful.

	      Return the status of the open device, as obtained with a
				   call.  If the operation was successful, an ACK is sent with the size of the status buffer, then the status buf-
				   fer is sent (in binary).

	      Return the status of the open device, as obtained with a
				   call.  If the operation was successful, an ACK is sent with the size of the status buffer, then the status buf-
				   fer is sent (in binary).  Return the status of the open device, as obtained with a call.  If the operation  was
				   successful,	an ACK is sent with the size of the status buffer, then the status buffer is sent in the following
				   ASCII format:

				   machine<blank>value<newline>
				   stat_struct_member_name<blank>value<newline>

				   The end of the data is indicated by an ASCII NULL character.  See for  the  definition.   In  addition  to  the
				   struct  stat  information,  there is an entry in the buffer describing the machine type as returned from a call
				   (see uname(2)).  In the above format ``machine'' is a key word.  All fields except of the are returned.

	      Return the status of the open device, as obtained with a
				   call.  If the operation was successful, an is sent with the size of the status buffer, then the  status  buffer
				   is sent in the following ASCII format:

				   machine<blank>value<newline>
				   mtget_struct_member_name<blank>value<newline>

				   The	end  of  the  data  is	indicated by an ASCII NULL character.  See for the definition.	In addition to the
				   struct mtget information there is an entry in the buffer describing the machine type as returned from  a  call.
				   In the above format "machine" is a keyword.

       Any other command causes to exit.

RETURN VALUE

       Device status is returned in the field contains defined macros for checking the status bits.

DIAGNOSTICS

       All responses are of the form described above.

WARNINGS

       Use of this command for remote file access protocol is discouraged.

AUTHOR

       was developed by the University of California, Berkeley.

SEE ALSO

       ftio(1), fbackup(1M), frecover(1M), dump(1M), restore(1M), rcmd(3N), rexec(3N).

																	   rmt(1M)