MT(1) | General Commands Manual | MT(1)

# NAME

`mt`, `eject` — magnetic tape and removable media manipulating program

# SYNOPSIS

`mt` | [`-f` device] command [count]

`eject` | [`-t`] device

# DESCRIPTION

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:

`-f` device
  Operate on the device specified.

The options for `eject` are as follows:

`-t`
  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.

`eof`, `weof`
  Write count end-of-file marks at the current position on the tape.
`fsf`
  Forward space count files.
`fsr`
  Forward space count records.
`bsf`
  Back space count files.
`bsr`
  Back space count records.
`rewind`
  Rewind the tape (count `is ignored`).
`offline`, `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).
`status`
  Print status information about the tape unit.
`retension`
  Retension the tape (if this operation is supported by the tape unit).
`erase`
  Erase the tape (if this operation is supported by the tape unit).
`eom`
  Forward space to the end of the media.
`blocksize`
  Set the tape blocksize to count bytes.
`density`
  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`.

# ENVIRONMENT

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

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

# FILES

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

# EXIT STATUS

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

# EXAMPLES

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

`$ eject /dev/rcd0c`

# SEE ALSO

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

# HISTORY

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

January 16, 2020 | Debian