RMT(1) manual page
Table of Contents
rmt - remote magnetic tape server
rmt
Rmt
provides remote access to files and devices for tar(1)
, cpio(1)
, and similar
backup utilities. It is normally called by running rsh(1)
or ssh(1)
to
the remote machine, optionally using a different login name if one is supplied.
The calling program communicates with rmt by sending requests on its standard
input and reading replies from the standard output. A request consists
of a request letter followed by an argument (if required) and a newline
character. Additional data, if any, are sent after the newline. On success,
rmt returns
Anumber\n
where number is an ASCII representation of a decimal
return code. Additional data are returned after this line. On error, the
following response is returned:
Eerrno\nerror-message\n
where errno is one
of the system error codes, as described in errno(3)
, and error-message is
a one-line human-readable description of the error, as printed by perror(3)
.
Available commands and possible responses are discussed in detail in the
subsequent section.
- Odevice\nflags\n
- Opens the device with given flags.
If a device had already been opened, it is closed before opening the new
one.
Arguments
- device
- The name of the device to open.
- flags
- Flags for open(2)
:
a decimal number, or any valid O_* constant from fcntl.h (the initial O_
may be omitted), or a bitwise or (using |) of any number of these, e.g.:
576 64|512 CREAT|TRUNC
In addition, a combined form is also allowed, i.e.
a decimal mode followed by its symbolic representation. In this case the
symbolic representation is given preference.
Reply
A0\n on success.
Extensions
BSD version allows only decimal number as flags.
- C[device]\n
- Close the currently
open device.
- Arguments
Any arguments are silently ignored. - Reply
A0\n on success.
- Lwhence\noffset\n
Performs an lseek(2)
on the currently open
device with the specified parameters.
- Arguments
- whence
- Where to measure
offset from. Valid values are:
0, SET, SEEK_SET seek from the file beginning
1, CUR, SEEK_CUR seek from the current location
2, END, SEEK_END seek from the file end
- Reply
Aoffset\n on success. The offset is the new offset in file. - Extensions
- BSD
version allows only 0,1,2 as whence.
- Rcount\n
Read count bytes of data from the current device. - Arguments
- count
- number
of bytes to read.
- Reply
On success:
Ardcount\n
followed by rdcount bytes of data read from the
device.
- Wcount\n
- Writes data onto the current device. The command is followed
by count bytes of input data.
- Arguments
- count
- Number of bytes to write.
- Reply
On success: Awrcount\n, where wrcount is the number of bytes actually written.
- Iopcode\ncount\n
- Perform a MTIOCOP ioctl(2)
command with the specified paramedters.
- Arguments
- opcode
- MTIOCOP operation code.
- count
- mt_count.
- Reply
On success: A0\n.
- S\n
- Returns the status of the currently open device, as
obtained from a MTIOCGET ioctl(2)
call.
- Arguments
None - Reply
On success: Acount\n followed by count bytes of data.
tar(1)
.
Using
this utility as a general-purpose remote file access tool is discouraged.
Report bugs to <bug-tar@gnu.org>.
The rmt command appeared
in 4.2BSD. The GNU rmt is written from scratch, using the BSD specification.
Copyright © 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html
>
This is free software: you are free to change and redistribute it. There
is NO WARRANTY, to the extent permitted by law.
Table of Contents
![[Go to CFHT Home Page]](/images/cfht-icon.gif){kind=icon}
Man Pages 
Back to Software Index 
Manpage Top Level