rmt(8)                              CLIX                              rmt(8)



  NAME

    rmt - Controls a remote magnetic tape drive

  SYNOPSIS

    /etc/rmt

  DESCRIPTION

    The rmt program is used by the remote dump and restore programs to control
    a magnetic tape drive through an interprocess communication connection.
    This program is normally started through an rexec or rcmd (3X) call.

    The rmt program accepts requests specific to the manipulation of magnetic
    tapes, performs the commands, then responds with a status indication.

    The protocol is comprised of the following commands (a space is present
    between each token):

    O device mode
           Open the specified device (a full pathname) using the indicated
           mode (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.  The rmt program 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.

    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.  The rmt program then performs the requested
           read(2) and responds with Acount-read- 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



  2/94 - Intergraph Corporation                                              1

  rmt(8)                              CLIX                              rmt(8)



           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, and then the status buffer is sent
           (in binary).

    Any other command causes rmt to exit.

  NOTES

    This program should not be used for a remote file access protocol.

  DIAGNOSTICS

    Successful commands result in responses such as

    Anumber-

    where number is an ASCII representation of a decimal number.

    Unsuccessful commands result in responses such as

    Eerror-number-error-message-,

    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(3).

  RELATED INFORMATION

    Commands:  rdump(8), rrestore(8)

    Functions:  rcmd(3), rexec(3)

    Files:   mtio(4)

















  2                                              Intergraph Corporation - 2/94