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)