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
(countis ignored).
-offline, rewoffl
Rewind the tape and place the tape unit off-line
(countis 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.
mt
returns a 0 exit status when the operation(s) were successful,
1 if the command was unrecognized, and 2 if an operation failed.
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
/dev/rmt*
raw magnetic tape interface
/usr/src/sys/scsi/scsi_tape.h
list of SCSI2 density codes
EXAMPLES
Eject the first CD device.
This will work even if there is no CD in the drive:
$ eject /dev/rcd0c