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(screen.info)Window Types

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Window Types
============

   Screen provides three different window types. New windows are created
with `screen''s `screen' command (Note: Screen Command).  The first
parameter to the `screen' command defines which type of window is
created. The different window types are all special cases of the normal
type. They have been added in order to allow `screen' to be used
efficiently as a console with 100 or more windows.
   * The normal window contains a shell (default, if no parameter is
     given) or any other system command that could be executed from a
     shell.  (e.g. `slogin', etc...).

   * If a tty (character special device) name (e.g. `/dev/ttya') is
     specified as the first parameter, then the window is directly
     connected to this device.  This window type is similar to `screen
     cu -l /dev/ttya'.  Read and write access is required on the device
     node, an exclusive open is attempted on the node to mark the
     connection line as busy.  An optional parameter is allowed
     consisting of a comma separated list of flags in the notation used
     by `stty(1)':
    `<baud_rate>'
          Usually 300, 1200, 9600 or 19200. This affects transmission
          as well as receive speed.

    `cs8 or cs7'
          Specify the transmission of eight (or seven) bits per byte.

    `ixon or -ixon'
          Enables (or disables) software flow-control (CTRL-S/CTRL-Q)
          for sending data.

    `ixoff or -ixoff'
          Enables (or disables) software flow-control for receiving
          data.

    `istrip or -istrip'
          Clear (or keep) the eight bit in each received byte.

     You may want to specify as many of these options as applicable.
     Unspecified options cause the terminal driver to make up the
     parameter values of the connection. These values are system
     dependant and may be in defaults or values saved from a previous
     connection.

     For tty windows, the `info' command shows some of the modem
     control lines in the status line.  These may include `RTS', `CTS',
     `DTR', `CD' and more. This depends rather on on the available
     `ioctl()''s and system header files than on the physical
     capabilities of the serial board.  The name of a logical low
     (inactive) signal is preceded by an exclamation mark (`!'),
     otherwise the signal is logical high (active).  Unsupported but
     shown signals are usually shown low.  When the `CLOCAL' status bit
     is true, the whole set of modem signals is placed inside curly
     braces (`{' and `}').  When the `CRTSCTS' or `TIOCSOFTCAR' bit is
     true, the signals `CTS' or `CD' are shown in parenthesis,
     respectively.

     For tty windows, the command `break' causes the Data transmission
     line (TxD) to go low for a specified period of time. This is
     expected to be interpreted as break signal on the other side.  No
     data is sent and no modem control line is changed when a `break'
     is issued.

   * If the first parameter is `//telnet', the second parameter is
     expected to be a host name, and an optional third parameter may
     specify a TCP port number (default decimal 23). Screen will
     connect to a server listening on the remote host and use the
     telnet protocol to communicate with that server.

     For telnet windows, the command `info' shows details about the
     connection in square brackets (`[' and `]') at the end of the
     status line.
    `b'
          BINARY. The connection is in binary mode.

    `e'
          ECHO. Local echo is disabled.

    `c'
          SGA. The connection is in `character mode' (default: `line
          mode').

    `t'
          TTYPE. The terminal type has been requested by the remote
          host. Screen sends the name `screen' unless instructed
          otherwise (see also the command `term').

    `w'
          NAWS. The remote site is notified about window size changes.

    `f'
          LFLOW. The remote host will send flow control information.
          (Ignored at the moment.)  Additional flags for debugging are
     `x', `t' and `n' (XDISPLOC, TSPEED and NEWENV).

     For telnet windows, the command `break' sends the telnet code `IAC
     BREAK' (decimal 243) to the remote host.