Provided by: mosh_1.2.5-2_amd64 
NAME
mosh - mobile shell with roaming and intelligent local echo
SYNOPSIS
mosh [options] [--] [user@]host [command...]
DESCRIPTION
mosh (mobile shell) is a remote terminal application that supports intermittent connectivity, allows
roaming, and provides speculative local echo and line editing of user keystrokes.
Compared with ssh, mosh is more robust — its connections stay up across sleeps and changes in the
client's IP address — and more responsive, because the protocol is tolerant of packet loss and the client
can echo most keystrokes immediately, without waiting for a network round-trip.
mosh uses ssh to establish a connection to the remote host and authenticate with existing means (e.g.,
public-key authentication or a password). mosh executes the unprivileged mosh-server helper program on
the server, then closes the SSH connection and starts the mosh-client, which establishes a long-lived
datagram connection over UDP.
To improve responsiveness, mosh runs a predictive model of the server's behavior in the background,
trying to guess the effect of each keystroke on the screen. It makes predictions for normal typing,
backspace, and the left- and right-arrow keys. When it is confident, mosh displays the predictions
without waiting for the server. The predictive model must prove itself anew on each row of the terminal
and after each control character, so mosh avoids echoing passwords or non-echoing editor commands.
By default, mosh shows its predictions only on high-latency connections and to smooth out network
glitches. (On longer-latency links, the predicted cells are underlined until confirmed by the server.)
Occasional echo mistakes are corrected within a network round-trip and do not cause lasting effect.
mosh does not support X forwarding or the non-interactive uses of SSH, including port forwarding or
sshfs. mosh works through typical client-side network address translators but requires UDP to pass
between client and server. By default, mosh uses the ports between 60000 and 61000, but allows the user
to request a particular UDP port instead.
mosh will do its best to arrange a UTF-8 character set locale on the client and server. The client must
have locale-related environment variables that specify UTF-8. mosh will pass these client variables to
the mosh-server on its command line, but in most cases they will not need to be used. mosh-server first
attempts to use its own locale-related environment variables, which come from the system default
configuration (sometimes /etc/default/locale) or from having been passed over the SSH connection. But if
these variables don't call for the use of UTF-8, mosh-server will apply the locale-related environment
variables from the client and try again.
OPTIONS
command
Command to run on remote host. By default, mosh executes a login shell.
--client=PATH
path to client helper on local machine (default: "mosh-client")
--server=COMMAND
command to run server helper on remote machine (default: "mosh-server")
The server helper is unprivileged and can be installed in the user's home directory.
--ssh=COMMAND
OpenSSH command to remotely execute mosh-server on remote machine (default: "ssh")
An alternate ssh port can be specified with, e.g., --ssh="ssh -p 2222".
--predict=WHEN
Controls use of speculative local echo. WHEN defaults to `adaptive' (show predictions on slower
links and to smooth out network glitches) and can also be `always` or `never'.
The MOSH_PREDICTION_DISPLAY environment variable controls this setting permanently and can adopt
the same three values.
Even on `always', mosh will only show predictions when it is confident. This generally means a
previous prediction on the same row of the terminal has been confirmed by the server, without any
intervening control character keystrokes.
-a Synonym for --predict=always
-n Synonym for --predict=never
--family=FAMILY
Force the use of a particular address family, which defaults to `inet' (IPv4), and can also be
`inet6' (IPv6; requires IO::Socket::IP or IO::Socket::INET6).
-4 Synonym for --family=inet
-6 Synonym for --family=inet6
-p PORT[:PORT2], --port=PORT[:PORT2]
Use a particular server-side UDP port or port range, for example, if this is the only port that is
forwarded through a firewall to the server. Otherwise, mosh will choose a port between 60000 and
61000.
--bind-server={ssh|any|IP}
Control the IP address that the mosh-server binds to.
The default is `ssh', in which case the server will reply from the IP address that the SSH
connection came from (as found in the SSH_CONNECTION environment variable). This is useful for
multihomed servers.
With --bind-server=any, the server will reply on the default interface and will not bind to a
particular IP address. This can be useful if the connection is made through sslh or another tool
that makes the SSH connection appear to come from localhost.
With --bind-server=IP, the server will attempt to bind to the specified IP address.
--no-init
Do not send the smcup initialization string and rmcup deinitialization string to the client's
terminal. On many terminals this disables alternate screen mode.
ESCAPE SEQUENCES
The default escape character used by Mosh is ASCII RS (decimal 30). This is typically typed as Ctrl-^ or
Ctrl-Shift-6, on US English keyboards. Users of non-English keyboards may find it difficult or
impossible to type the default escape character, and may need to change the escape character. See the
description of MOSH_ESCAPE_KEY, below. In this description, the configured escape character is
represented as Esc.
There are two slightly different modes for escape sequences, depending whether the escape character is
printable or not.
If the escape character is a printable character, it must be prefixed with a newline, similar to OpenSSH.
To send the escape character itself, type it twice. If the escape character is set to ~, mosh will
behave much like OpenSSH.
If the escape character is a non-printable control character, no prefix is used and the escape character
is recognized at any time. To send the escape character itself, type the escape character, then its
corresponding ASCII character (for Ctrl-^ you would type ^, for Ctrl-B you would type B).
The escape sequence to shut down the connection is Esc .. The sequence Esc Ctrl-Z suspends the client.
Any other sequence passes both characters through to the server.
ENVIRONMENT VARIABLES
These variables are not actually interpreted by mosh(1) itself, but are passed through to mosh-server(1). They are described here for ease of use. MOSH_ESCAPE_KEY When set, this configures the escape character used for local commands. The escape character may be set to any ASCII character in the range 1-127. The variable must be set with a single literal ASCII character. Control characters are set with the actual ASCII control character, not with a printable representation such as "^B". MOSH_PREDICTION_DISPLAY Controls local echo as described above. The command-line flag overrides this variable. MOSH_TITLE_NOPREFIX When set, inhibits prepending "[mosh]" to window title.
SEE ALSO
mosh-client(1), mosh-server(1). Project home page: http://mosh.mit.edu
AUTHOR
mosh was written by Keith Winstein <mosh-devel@mit.edu>.
BUGS
Please report bugs to mosh-devel@mit.edu. Users may also subscribe to the mosh-users@mit.edu mailing list, at http://mailman.mit.edu/mailman/listinfo/mosh-users April 2013 MOSH(1)