.\"	$OpenBSD: mt.1,v 1.7 1998/07/03 07:02:20 deraadt Exp $
.\"	$NetBSD: mt.1,v 1.8 1996/05/21 10:23:55 mrg Exp $
.\"
.\" Copyright (c) 1981, 1990, 1993
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.\"    may be used to endorse or promote products derived from this software
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.\"	@(#)mt.1	8.1 (Berkeley) 6/6/93
.\"
.Dd June 12, 1996
.Dt MT 1
.Os OpenBSD
.Sh NAME
.Nm mt ,
.Nm eject
.Nd magnetic tape and removable media manipulating program
.Sh SYNOPSIS
.Nm mt
.Op Fl f Ar tapename
.Ar command
.Op Ar count
.Nm eject
.Op Fl f
.Ar tapename
.Sh DESCRIPTION
.Nm Mt
is used to give commands to a magnetic tape drive.
By default
.Nm mt
performs the requested operation once.  Operations
may be performed multiple times by specifying
.Ar count  .
Note
that
.Ar tapename
must reference a raw (not block) tape device.
If
.Ar tapename
is of the form
.Dq host:tapename ,
or
.Dq user@host:tapename ,
.Nm mt
writes to the named tape device on the remote host using
.Xr rmt 8 .
.Pp
The available commands are listed below.  Only as many
characters as are required to uniquely identify a command
need be specified.
.Bl -tag -width "eof, weof"
.It Cm eof , weof
Write
.Ar count
end-of-file marks at the current position on the tape.
.It Cm fsf
Forward space
.Ar count
files.
.It Cm fsr
Forward space
.Ar count
records.
.It Cm bsf
Back space
.Ar count
files.
.It Cm bsr
Back space
.Ar count
records.
.It Cm rewind
Rewind the tape
(Count is ignored).
.It Cm offline , rewoffl
Rewind the tape and place the tape unit off-line
(Count is ignored).  On non-tape removable media, the
.Cm offline
command causes the media to be ejected when the last operation on it
closes (i.e., the filesystem is unmounted).
.It Cm status
Print status information about the tape unit.
.It Cm retension
Retensions the tape (if this operation is supported by the tape unit).
.It Cm erase
Erases the tape (if this operation is supported by the tape unit).
.It Cm eom
Forward space to the end of the media.
.It Cm blocksize
Set the tape blocksize to
.Ar count
bytes.
.It Cm density
Set the tape density code to
.Ar count
as specified in the SCSI2 specification.
.El
.Pp
.Nm Eject
is simply an alias for
.Nm mt ,
with the
.Cm offline
command specified.
.Pp
If a tape name is not specified, and the environment variable
.Ev TAPE
does not exist;
.Nm mt
uses the device
.Pa /dev/rst0 .
.Pp
.Nm Mt
returns a 0 exit status when the operation(s) were successful,
1 if the command was unrecognized, and 2 if an operation failed.
.Sh ENVIRONMENT
If the following environment variable exists, it is utilized by
.Nm mt .
.Bl -tag -width Fl
.It Ev TAPE
.Nm Mt
checks the
.Ev TAPE
environment variable if the
argument
.Ar tapename
is not given.
.Sh FILES
.Bl -tag -width /dev/rst* -compact
.It Pa /dev/rst*
Raw SCSI tape interface
.It Pa /dev/rmt*
Raw magnetic tape interface
.It Pa /usr/src/sys/scsi/scsi_tape.h
List of SCSI2 density codes
.El
.Sh SEE ALSO
.Xr mtio 4 ,
.Xr dd 1 ,
.Xr ioctl 2 ,
.Xr environ 7
.Sh HISTORY
The
.Nm mt
utility appeared in
.Bx 4.3 .
.\" mt.1: mtio(4) missing