RMT(8c,C)                   AIX Commands Reference                    RMT(8c,C)



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rmt



PURPOSE

Remote magnetic tape protocol module.

SYNTAX


rmt ----|


DESCRIPTION

The rmt command 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 or rcmd 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\error-message\n

where error-number is one of the possible error numbers described in intro and
error-message is the corresponding error string as printed from a call to
perror.  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 path name and mode is an ASCII representation of
                    a decimal number suitable for passing to open.  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 operation using the specified parameters.
                    The response value is that returned from the lseek call.






Processed November 8, 1990         RMT(8c,C)                                  1

RMT(8c,C)                   AIX Commands Reference                    RMT(8c,C)



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 call.

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 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 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.

RELATED INFORMATION

See the following commands:  "rdump" and "rrestore."

























Processed November 8, 1990         RMT(8c,C)                                  2