mt(1)

NAME

     mt - magnetic tape control

SYNOPSIS

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

DESCRIPTION

     The mt utility sends commands to a magnetic tape  drive.  If
     -f  tapename is not specified, the environment variable TAPE
     is used.  If  TAPE  does  not  exist,  mt  uses  the  device
     /dev/rmt/0n.

OPTIONS

     The following option is supported:

     -f tapename
           Specifies the raw tape device.

OPERANDS

     The following operands are supported:

     count The number of times that the requested operation is to
           be  performed.  By default, mt performs  command once.
           Multiple operations of  command may  be  performed  by
           specifying count.

     command
           Available commands that can be sent to a magnetic tape
           drive.  Only  as  many  characters  as are required to
           uniquely identify a command need be specified.

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

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

     fsr   Forward space count records.

     bsf   Back space over count EOF marks.  The  tape  is  posi-
           tioned 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.

     If count is specified with any of  the  following  commands,
     the count is ignored and the command is performed only once.

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

     rewind
           Rewind the tape.

     offline, rewoffl
           Rewind the tape and, if appropriate,  take  the  drive
           unit   off-line  by  unloading  the  tape.  It  cycles
           through all four  tapes.

     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.

     reserve
           Allow the tape drive to remain reserved after  closing
           the   device.   The  drive  must  then  be  explicitly
           released.

     release
           Re-establish the  default  behavior  of  releasing  at
           close.

     forcereserve
           Break the  reservation  of  the  tape  drive  held  by
           another  host  and  then  reserve the tape drive. This
           command  can  be   executed   only   with   super-user
           privileges.

     erase Erase the entire tape. Erasing a tape may take a  long
           time depending on the device and/or tape. Refer to the
           device specific manual for time details.

EXIT STATUS

     0     All operations were successful.

     1     Command was unrecognized or mt was unable to open  the
           specified tape drive.

     2     An operation failed.

FILES

     /dev/rmt/*
           magnetic tape interface

ATTRIBUTES

     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWcsu                     |
    |_____________________________|_____________________________|

SEE ALSO

     tar(1),  tcopy(1),  ar(3HEAD),  environ(4),   attributes(5),
     mtio( 7I), st(7D)

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, SPARC to x86 or the reverse) is not supported.