mt Command (BSD)

Purpose

Gives subcommands to streaming tape device.

Syntax

mt [  -f TapeName ] Subcommand [ Count ]

Description

The mt command gives subcommands to a streaming tape device. If you do not specify the -f flag with the TapeName parameter, the TAPE environment variable is used. If the environment variable does not exist, the mt command uses the /dev/rmt0.1 device. The TapeName parameter must be a raw (not block) tape device. You can specify more than one operation with the Count parameter.

Subcommands

Item Description
eof, weof Writes the number of end-of-file markers specified by the Count parameter at the current position on the tape.
fsf Moves the tape forward the number of files specified by the Count parameter and positions it to the beginning of the next file.
bsf Moves the tape backwards the number of files specified by the Count parameter and positions it to the beginning of the last file skipped. If using the bsf subcommand would cause the tape head to move back past the beginning of the tape, then the tape will be rewound, and the mt command will return EIO.
fsr Moves the tape forward the number of records specified by the Count parameter.
bsr Moves the tape backwards the number of records specified by the Count parameter.
rewoff1, rewind Rewinds the tape. The Count parameter is ignored.
status Prints status information about the specified tape device. The output of the status command may change in future implementations.

Flag

Item Description
-f TapeName Specifies the TapeName parameter.

Examples

  1. To rewind the rmt1 tape device, enter: 
    mt -f /dev/rmt1 rewind
  2. To move forward two files on the default tape device, enter: 
    mt fsf 2
  3. To write two end-of-file markers on the tape in the /dev/rmt0.6 file, enter: 
    mt -f /dev/rmt0.6 weof 2

Exit Status

Item Description
0 Indicates a successful completion.
>0 Indicates an error occurred.

Files

Item Description
/dev/rmt/n.n Specifies the raw streaming tape interface.
/usr/bin/mt Contains the mt command file.