.\" Copyright (c) 1983, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)rmt.8 8.3 (Berkeley) 6/1/94 .\" $FreeBSD: /repoman/r/ncvs/src/usr.sbin/rmt/rmt.8,v 1.13 2003/06/08 14:29:48 charnier Exp $ .\" .Dd June 1, 1994 .Dt RMT 8 .Os .Sh NAME .Nm rmt .Nd remote magtape protocol module .Sh SYNOPSIS .Nm .Sh DESCRIPTION The .Nm utility is used by the remote dump and restore programs in manipulating a magnetic tape drive through an interprocess communication connection. It is normally started up with an .Xr rexec 3 or .Xr rcmd 3 call. .Pp The .Nm utility accepts requests specific to the manipulation of magnetic tapes, performs the commands, then responds with a status indication. All responses are in .Tn ASCII and in one of two forms. Successful commands have responses of: .Bd -ragged -offset indent .Sm off .Sy A Ar number No \en .Sm on .Ed .Pp .Ar Number is an .Tn ASCII representation of a decimal number. Unsuccessful commands are responded to with: .Bd -ragged -offset indent .Sm off .Xo Sy E Ar error-number .No \en Ar error-message .No \en .Xc .Sm on .Ed .Pp .Ar Error-number is one of the possible error numbers described in .Xr intro 2 and .Ar error-message is the corresponding error string as printed from a call to .Xr perror 3 . The protocol is comprised of the following commands, which are sent as indicated - no spaces are supplied between the command and its arguments, or between its arguments, and .Ql \en indicates that a newline should be supplied: .Bl -tag -width Ds .Sm off .It Xo Sy \&O Ar device .No \en Ar mode No \en .Xc .Sm on Open the specified .Ar device using the indicated .Ar mode . .Ar Device is a full pathname and .Ar mode is an .Tn ASCII representation of a decimal number suitable for passing to .Xr open 2 . If a device had already been opened, it is closed before a new open is performed. .Sm off .It Xo Sy C Ar device No \en .Xc .Sm on Close the currently open device. The .Ar device specified is ignored. .Sm off .It Xo Sy L .Ar whence No \en .Ar offset No \en .Xc .Sm on Perform an .Xr lseek 2 operation using the specified parameters. The response value is that returned from the .Xr lseek 2 call. .Sm off .It Sy W Ar count No \en .Sm on Write data onto the open device. The .Nm utility reads .Ar count bytes from the connection, aborting if a premature end-of-file is encountered. The response value is that returned from the .Xr write 2 call. .Sm off .It Sy R Ar count No \en .Sm on Read .Ar count bytes of data from the open device. If .Ar count exceeds the size of the data buffer (10 kilobytes), it is truncated to the data buffer size. The .Nm utility then performs the requested .Xr read 2 and responds with .Sm off .Sy A Ar count-read No \en .Sm on if the read was successful; otherwise an error in the standard format is returned. If the read was successful, the data read is then sent. .Sm off .It Xo Sy I Ar operation .No \en Ar count No \en .Xc .Sm on Perform a .Dv MTIOCOP .Xr ioctl 2 command using the specified parameters. The parameters are interpreted as the .Tn ASCII representations of the decimal values to place in the .Ar mt_op and .Ar mt_count fields of the structure used in the .Xr ioctl 2 call. The return value is the .Ar count parameter when the operation is successful. .It Sy S Return the status of the open device, as obtained with a .Dv MTIOCGET .Xr ioctl 2 call. If the operation was successful, an ``ack'' is sent with the size of the status buffer, then the status buffer is sent (in binary). .El .Pp Any other command causes .Nm to exit. .Sh DIAGNOSTICS All responses are of the form described above. .Sh SEE ALSO .Xr rcmd 3 , .Xr rexec 3 , .Xr mtio 4 , .Xr rdump 8 , .Xr rrestore 8 .Sh BUGS People should be discouraged from using this for a remote file access protocol. .Sh HISTORY The .Nm utility appeared in .Bx 4.2 .