MT(1) General Commands Manual MT(1)
mt - magnetic tape control
mt [ -f tapename ] command [ count ]
mt sends commands to a magnetic tape drive. If tapename is not speci-
fied, the environment variable TAPE is used. If TAPE does not exist,
mt uses the device /dev/rmt12. tapename refers to a raw tape device.
By default, mt performs the requested operation once; multiple opera-
tions may be performed by specifying count.
The available commands are listed below. Only as many characters as
are required to uniquely identify a command need be specified.
mt returns a 0 exit status when the operation(s) were successful, 1 if
the command was unrecognized or if mt was unable to open the specified
tape drive, and 2 if an operation failed.
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 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 previously written tapes.
rewind Rewind the tape.
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.
/dev/rmt* magnetic tape interface
/dev/rar* Archive cartridge tape interface
/dev/rst* SCSI tape interface
ar(4S), mtio(4), st(4S), tm(4S), xt(4S) environ(5V)
Not all devices support all options. Some options are hardware-depen-
dent. Refer to the corresponding device manual page.
The bsf option for SCSI tape in SunOS 4.0.3 is incompatible with this
release and releases prior to 4.0.3.
19 December 1989 MT(1)