xenial (1) mosh.1.gz

Provided by: mosh_1.2.5-2_amd64 bug

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)