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MT(1) General Commands Manual MT(1)

mt, eject — magnetic tape and removable media manipulating program

mt [-f device] command [count]

eject [-t] device

The mt utility sends commands to a magnetic tape drive. By default, mt performs the requested operation once. Operations may be performed multiple times by specifying count. Note that device must reference a raw (not block) tape device. If device is of the form “host:device” or “user@host:device”, mt writes to the named tape device on the remote host using rmt(8). eject is simply an alias for mt, with the offline command specified. eject may also be used to eject other types of removable media.

The options for mt are as follows:

device
Operate on the device specified.

The options for eject are as follows:

Insert the device instead of ejecting. For the cd(4) driver, this requests that the tray be closed.

The available commands are listed below. Only as many characters as are required to uniquely identify a command need be specified.

, weof
Write count end-of-file marks at the current position on the tape.
Forward space count files.
Forward space count records.
Back space count files.
Back space count records.
Rewind the tape (count is ignored).
, rewoffl
Rewind the tape and place the tape unit off-line (count is ignored). On non-tape removable media, the offline command causes the media to be ejected when the last operation on it closes (i.e., the filesystem is unmounted).
Print status information about the tape unit.
Retension the tape (if this operation is supported by the tape unit).
Erase the tape (if this operation is supported by the tape unit).
Forward space to the end of the media.
Set the tape blocksize to count bytes.
Set the tape density code to count as specified in the SCSI2 specification.

If a tape name is not specified, and the environment variable TAPE does not exist, mt uses the device /dev/rst0. The TAPE variable is ignored by eject.

If the following environment variable exists, it is utilized by mt.

mt checks the TAPE environment variable if the argument device is not given.

/dev/rst*
raw SCSI tape interface
/usr/src/sys/scsi/scsi_tape.h
list of SCSI2 density codes

mt returns a 0 exit status when the operation(s) were successful, 1 if the command was unrecognized, and 2 if an operation failed.

Eject the first CD device. This will work even if there is no CD in the drive:

$ eject /dev/rcd0c

cdio(1), chio(1), dd(1), ioctl(2), mtio(4)

The mt utility appeared in Version 2 AT&T UNIX.

January 16, 2020 OpenBSD-current