NAME
     mt - magnetic tape control

SYNOPSIS
     mt [ -f tapename ] command... [ count ]

AVAILABILITY
     SUNWcsu

DESCRIPTION
     mt sends commands to a magnetic tape drive.  If tapename  is
     not  specified,  the  environment variable TAPE is used.  If
     TAPE  does  not  exist,  mt  uses  the  device   /dev/rmt/0.
     tapename  refers  to a raw tape device.  By default, mt per-
     forms the requested operation once;  multiple operations may
     be performed by specifying count.

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

     mt returns a 0 exit status when the operation(s)  were  suc-
     cessful,  1  if  the  command  was unrecognized or if mt was
     unable to open the specified tape drive, and 2 if an  opera-
     tion failed.

  mt Commands
     eof, weof    Write count EOF marks at the  current  position
                  on the tape.

     fsf          Forward space over count EOF marks. The tape is
                  positioned on the first block of the file.

     fsr          Forward space count records.

     bsf          Back space over count EOF marks.  The  tape  is
                  positioned on the beginning-of-tape side of the
                  EOF mark.

     bsr          Back space count records.

     nbsf         Back space count files.  The tape is positioned
                  on  the  first  block  of  the  file.   This is
                  equivalent to count+1  bsf's  followed  by  one
                  fsf.

     asf          Absolute space to count file number.   This  is
                  equivalent to a rewind followed by a fsf count.

     For the following commands, count is ignored:

     eom          Space to the end of recorded media on the tape.
                  This  is useful for appending files onto previ-
                  ously written tapes.

     rewind       Rewind the tape.

     offline, rewoffl
                  Rewind the tape and, if appropriate,  take  the
                  drive unit off-line by unloading the tape.

     status       Print status information about the tape unit.

     retension    Rewind the cartridge tape completely, then wind
                  it  forward  to the end of the reel and back to
                  beginning-of-tape to smooth out tape tension.

     erase        Erase the entire tape.

FILES
     /dev/rmt/*          magnetic tape interface
     /dev/rmt/*b
     /dev/rmt/*bn
     /dev/rmt/*c
     /dev/rmt/*cb
     /dev/rmt/*cbn
     /dev/rmt/*cn
     /dev/rmt/*h
     /dev/rmt/*hb
     /dev/rmt/*hbn
     /dev/rmt/*hn
     /dev/rmt/*l
     /dev/rmt/*lb
     /dev/rmt/*lbn
     /dev/rmt/*ln
     /dev/rmt/*m
     /dev/rmt/*mb
     /dev/rmt/*mbn
     /dev/rmt/*mn
     /dev/rmt/*n
     /dev/rmt/*u
     /dev/rmt/*ub
     /dev/rmt/*ubn
     /dev/rmt/*un

SEE ALSO
     tar(1), tcopy(1), ar(4), environ(4), mtio(7), st(7)

BUGS
     Not all devices  support  all  options.   Some  options  are
     hardware-dependent.    Refer  to  the  corresponding  device
     manual page.


     mt is architecture sensitive. Heterogeneous operation  (that
     is, Sun3 to Sun4 or visa versa) is not supported.