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 rep-
resentations 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 5.10 6 Nov 2000 rmt(1M)