. \" @(#)smt.1	1.1 04/09/26 Copyr 2004 J. Schilling
. \"  Manual Seite fuer smt
. \"
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.TH SMT 1 "04/09/26" "J\*org Schilling" "Schily\'s USER COMMANDS"
.SH NAME
smt \- magnetic tape control
.SH SYNOPSIS
.B smt
[
.BI \-f " tapename
]
.I command
[
.I count
] 
.SH DESCRIPTION
.PP
The
.B smt
program sends commands to a local or a remote magnetic tape drive.
.PP
The
.I count
operand specifies the number of times the requested command is
to be performed. If
.I count
is omitted, the value of
.I count
defaults to one.
.SH OPTIONS
.TP
.B \-help
Prints a summary of the options for
.BR smt (1)
and exits.
.TP
.B \-version
Prints the 
.B smt
version number string and exists.
.TP
.B \-debug
print additional debug messages.
.TP
.BI \-f " tapename
.TP
.BI \-t " tapename
Set the raw tape device to use, otherwise
.B smt
uses a system specific default for the rtape device.
If 
.B smt
is installed suid root or if it has been called by root,
.I tapename
may be in remote syntax: user@host:filename as in 
.BR rcp (1)
even if 
invoked by non root users.
See SUID NOTES for more information.
.sp
To make a file local although it includes a colon (:), the filename
must start with:
.IR "'/'" ,
.IR "'./'" " or"
.I "'../'"
.sp
Note that if
.B smt 
talks to an old 
.B rmt
remote tape server that does not support symbolic open modes,
it does not open a remote tape with the 
.B O_CREAT
open flag because this would be extremely dangerous.
If the 
.B rmt 
server on the other side is the 
.B rmt
server that comes with 
.B star
or the GNU
.B rmt
server,
.B smt
may use the symbolic mode for the open flags.
Only the symbolic open modes allow to send all possible open
modes in a portable way to remote tape servers.
.sp
It is recommended to use the 
.B rmt
server that comes with
.BR star .
It is the only
.B rmt
server that gives platform independent compatibility with BSD, Sun and GNU
.B rmt 
clients and it includes security features that may be set up in /etc/default/rmt.
.sp
See ENVIRONMENT section for information on how to use 
.B ssh(1)
to create a remote tape server connection.
.TP
.B \-wready
Wait for the tape drive to become ready before executing the command.
.SH COMMANDS
The following commands are supported:
.TP 12
.B eof
.TP
.B weof
Write
.I count
EOF (FILE) marks at the current position on the tape.
.sp
This command may be run remotely with any BSD compliant old rmt server.
.TP
.B fsf
Forward skip over
.I count
FILE marks.
The tape is positioned on the first block of the file.
.sp
This command may be run remotely with any BSD compliant old rmt server.
.TP
.B bsf
Backward skip 
.I count
FILE marks.
The tape is positioned on side of the FILE mark
that is closer to the beginning of the tape.
.sp
This command may be run remotely with any BSD compliant old rmt server.
.TP
.B asf
Absolute FILE mark positioning to file number
.IR count .
This is equivalent to a rewind followed by a
.BI fsf " count.
.sp
A RMT version 1 server is needed to run this command on a remote tape drive.
.TP
.B fsr
Forward skip
.I count 
tape records.
.sp
This command may be run remotely with any BSD compliant old rmt server.
.TP
.B bsr
Backward skip
.I count 
tape records.
.sp
This command may be run remotely with any BSD compliant old rmt server.
.TP
.B rewind
Rewind the tape.
.sp
This command may be run remotely with any BSD compliant old rmt server.
.TP
.B offline
.TP
.B rewoffl
Rewind the tape.
If the specified tape drive allows to take the drive off-line
or to unload the tape, a off-line or unload operation is performed
in addition.
.sp
This command may be run remotely with any BSD compliant old rmt server.
.TP
.B status
Retrieve and print status information for the tape drive.
.sp
A RMT version 1 server is needed to get correct status information
on a remote tape drive.
.TP
.B nop
No operation.
If you only like to wait for the tape drive to become ready, call
.BR "smt -wready nop" .
.sp
This command may be run remotely with any BSD compliant old rmt server.
.TP
.B retension
Retension the tape. This only makes sende with cartridge tape drives.
.sp
A RMT version 1 server is needed to run this command on a remote tape drive.
.TP
.B erase
Erase the entire tape. This may take a long time (up to several hours)
depending on the tape drive and the medium.
.sp
A RMT version 1 server is needed to run this command on a remote tape drive.
.TP
.B eom
Position the tape to the end of the recorded media.
This allows to append data to previously written tapes.
.sp
A RMT version 1 server is needed to run this command on a remote tape drive.
.TP
.B nbsf
Backward skip 
.I count
FILE marks.
The tape is positioned on side of the FILE mark
that is closer to the end of the tape. This is before the first
block of the file.
The 
.B nbsf 
command is equivalent to 
.I count+1
.B bsf's
followed by one
.BR fsf .
.sp
A RMT version 1 server is needed to run this command on a remote tape drive.
.TP
.B load
If the specified tape drive allows to take the drive on-line
or to load the tape, a on-line or load operation is performed.
in addition.
For remote tape drives, this command only works if the remote tape server
supports symbolic open modes as the command needs the 
.I O_NDELAY
flag to succeed.
.sp
A RMT version 1 server is needed to run this command on a remote tape drive.
.SH EXAMPLES
.SH ENVIRONMENT
.TP
.B RSH
If the 
.B RSH
environment is present, the remote connection will not be created via
.BR rcmd (3)
but by calling the program pointed to by
.BR RSH .
Use e.g. 
.BR RSH= /usr/bin/ssh
to create a secure shell connection.
.sp
Note that this forces 
.B smt
to create a pipe to the 
.B rsh(1)
program and disallows
.B smt
to directly access the network socket to the remote server.
This makes it impossible to set up performance parameters and slows down
the connection compared to a 
.B root
initiated
.B rcmd(3)
connection.
.TP
.B RMT
If the 
.B RMT
environment is present, the remote tape server will not be the program
.B /etc/rmt
but the program pointed to by
.BR RMT .
Note that the remote tape server program name will be ignored if you log in
using an account that has been created with a remote tape server program as
login shell.
.TP
.B TAPE
In case no 
.B \-f
option pas been specified, the default tape name is taken from the
.B TAPE
environment.

.SH FILES
.SH "SEE ALSO"
.BR spax (1), 
.BR suntar (1), 
.BR scpio (1), 
.BR tar (1), 
.BR cpio (1), 
.BR pax (1), 
.BR rcp (1), 
.BR mt (1),
.BR rmt (1), 
.BR match (1), 
.BR dd (1), 
.BR sdd (1), 
.BR rsh (1),
.BR ssh (1),
.BR star (1),
.BR star (4/5),
.BR rcmd (3),
.SH DIAGNOSTICS
.SH NOTES
If the remote tape server is running Linux and the remote tape server on
such a system is not the rmt server that comes with 
.BR star (1),
then completely unexpected results (including unexpectedly erased tapes)
may occur. This is because Linux ignores the numbering values for the
magnetic tape op codes and only the rmt server from
.BR star (1)
maps to standard values.
The standard rmt server on Linux for this reason may not be called
BSD compliant.
.SH BUGS
.SH AUTHOR
.nf
J\*org Schilling
Seestr. 110
D\-13353 Berlin
Germany
.fi
.PP
Mail bugs and suggestions to:
.PP
.B
schilling@fokus.fraunhofer.de
or
.B
js@cs.tu\-berlin.de
or
.B
joerg@schily.isdn.cs.tu\-berlin.de