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MODBUS_TCP_LISTEN(3)           Libmodbus Manual           MODBUS_TCP_LISTEN(3)


NAME

       modbus_tcp_listen - create and listen a TCP Modbus socket


SYNOPSIS

       int modbus_tcp_listen(modbus_t *ctx, int nb_connection);


DESCRIPTION

       The modbus_tcp_listen() function shall create a socket and listen for
       nb_connection incoming connections.


RETURN VALUE

       The modbus_tcp_listen() function shall return a new socket if
       successful. Otherwise it shall return -1 and set errno.


EXAMPLE

       For a detailed example, see source file bandwith-server-many-up.c
       provided in tests directory.

           ...

           ctx = modbus_new_tcp("127.0.0.1", 502);
           if (modbus_connect(ctx) == -1) {
               fprintf(stderr, "Connection failed: %s\n", modbus_strerror(errno));
               modbus_free(ctx);
               return -1;
           }

           /* Handle until 10 established connections */
           server_socket = modbus_tcp_listen(ctx, 10);

           /* Clear the reference set of socket */
           FD_ZERO(&refset);

           /* Add the server socket */
           FD_SET(server_socket, &refset);

           if (select(server_socket + 1, &refset, NULL, NULL, NULL) == -1) {
           }

           ...

           close(server_socket);
           modbus_free(ctx);


SEE ALSO

       modbus_tcp_accept(3) modbus_tcp_pi_accept(3) modbus_tcp_pi_listen(3)


AUTHORS

       The libmodbus documentation was written by Stephane Raimbault
       <stephane.raimbault@gmail.com[1]>


NOTES

        1. stephane.raimbault@gmail.com
           mailto:stephane.raimbault@gmail.com

libmodbus 3.1.0                   10/06/2013              MODBUS_TCP_LISTEN(3)

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