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       slave - Functions for starting and controlling slave nodes.


       This  module  provides functions for starting Erlang slave nodes. All slave nodes that are
       started by a master terminate automatically  when  the  master  terminates.  All  terminal
       output produced at the slave is sent back to the master node. File I/O is done through the

       Slave nodes on other hosts than the current one are started with the rsh program. The user
       must be allowed to rsh to the remote hosts without being prompted for a password. This can
       be arranged in a number of ways (for details, see the rsh  documentation).  A  slave  node
       started  on  the  same  host  as  the  master inherits certain environment values from the
       master, such as the current directory and the  environment  variables.  For  what  can  be
       assumed  about  the  environment  when  a  slave  is  started  on  another  host,  see the
       documentation for the rsh program.

       An alternative to the rsh program can be specified  on  the  command  line  to  erl(1)  as

       -rsh Program

       The slave node is to use the same file system at the master. At least, Erlang/OTP is to be
       installed in the same place on both computers and the same version  of  Erlang  is  to  be

       A node running on Windows can only start slave nodes on the host on which it is running.

       The master node must be alive.


       pseudo([Master | ServerList]) -> ok


                 Master = node()
                 ServerList = [atom()]

              Calls pseudo(Master, ServerList). If you want to start a node from the command line
              and set up a number of pseudo servers, an Erlang runtime system can be  started  as

              % erl -name abc -s slave pseudo klacke@super x --

       pseudo(Master, ServerList) -> ok


                 Master = node()
                 ServerList = [atom()]

              Starts  a  number  of pseudo servers. A pseudo server is a server with a registered
              name that does nothing but pass on all message to the real server that executes  at
              a master node. A pseudo server is an intermediary that only has the same registered
              name as the real server.

              For example, if you have started a slave node N and want to  execute  pxw  graphics
              code  on this node, you can start server pxw_server as a pseudo server at the slave
              node. This is illustrated as follows:

              rpc:call(N, slave, pseudo, [node(), [pxw_server]]).

       relay(Pid) -> no_return()


                 Pid = pid()

              Runs a pseudo server. This function never returns any value and  the  process  that
              executes the function receives messages. All messages received are simply passed on
              to Pid.

       start(Host) -> {ok, Node} | {error, Reason}

       start(Host, Name) -> {ok, Node} | {error, Reason}

       start(Host, Name, Args) -> {ok, Node} | {error, Reason}


                 Host = inet:hostname()
                 Name = atom() | string()
                 Args = string()
                 Node = node()
                 Reason = timeout | no_rsh | {already_running, Node}

              Starts a slave node on host Host. Host names need not necessarily be  specified  as
              fully  qualified  names;  short  names can also be used. This is the same condition
              that applies to names of distributed Erlang nodes.

              The name of the started node becomes Name@Host. If no name is  provided,  the  name
              becomes  the  same as the node that executes the call (except the host name part of
              the node name).

              The slave node resets its user process so that all terminal I/O that is produced at
              the slave is automatically relayed to the master. Also, the file process is relayed
              to the master.

              Argument Args is used to set erl command-line arguments. If provided, it is  passed
              to the new node and can be used for a variety of purposes; see erl(1).

              As an example, suppose that you want to start a slave node at host H with node name
              Name@H and want the slave node to have the following properties:

                * Directory Dir is to be added to the code path.

                * The Mnesia directory is to be set to M.

                * The Unix DISPLAY environment variable is to be set to the display of the master

              The following code is executed to achieve this:

              E = " -env DISPLAY " ++ net_adm:localhost() ++ ":0 ",
              Arg = "-mnesia_dir " ++ M ++ " -pa " ++ Dir ++ E,
              slave:start(H, Name, Arg).

              The  function returns {ok, Node}, where Node is the name of the new node, otherwise
              {error, Reason}, where Reason can be one of:

                  The master node failed to get in contact with the slave node. This can occur in
                  a number of circumstances:

                  * Erlang/OTP is not installed on the remote host.

                  * The  file  system  on  the  other  host  has a different structure to the the

                  * The Erlang nodes have different cookies.

                  There is no rsh program on the computer.

                {already_running, Node}:
                  A node with name Name@Host already exists.

       start_link(Host) -> {ok, Node} | {error, Reason}

       start_link(Host, Name) -> {ok, Node} | {error, Reason}

       start_link(Host, Name, Args) -> {ok, Node} | {error, Reason}


                 Host = inet:hostname()
                 Name = atom() | string()
                 Args = string()
                 Node = node()
                 Reason = timeout | no_rsh | {already_running, Node}

              Starts a slave node in the same way as start/1,2,3, except that the slave  node  is
              linked  to  the  currently executing process. If that process terminates, the slave
              node also terminates.

              For a description of arguments and return values, see start/1,2,3.

       stop(Node) -> ok


                 Node = node()

              Stops (kills) a node.