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

       -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.

       --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 escape sequence to shut down the connection is Ctrl-^ .  (typically typed  with  Ctrl-
       Shift-6,  then  a  period).  To  send a literal Ctrl-^, type Ctrl-^ ^. The sequence Ctrl-^
       Ctrl-Z suspends the client.

ENVIRONMENT VARIABLES

       MOSH_PREDICTION_DISPLAY
              Controls local echo as described above.

       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

                                           October 2012                                   MOSH(1)