1MODBUS_TCP_LISTEN(3)           Libmodbus Manual           MODBUS_TCP_LISTEN(3)
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NAME

6       modbus_tcp_listen - create and listen a TCP Modbus socket
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SYNOPSIS

9       int modbus_tcp_listen(modbus_t *ctx, int nb_connection);
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DESCRIPTION

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

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

20       For a detailed example, see source file bandwith-server-many-up.c
21       provided in tests directory.
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23           ...
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25           ctx = modbus_new_tcp("127.0.0.1", 502);
26           if (modbus_connect(ctx) == -1) {
27               fprintf(stderr, "Connection failed: %s\n", modbus_strerror(errno));
28               modbus_free(ctx);
29               return -1;
30           }
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32           /* Handle until 10 established connections */
33           server_socket = modbus_tcp_listen(ctx, 10);
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35           /* Clear the reference set of socket */
36           FD_ZERO(&refset);
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38           /* Add the server socket */
39           FD_SET(server_socket, &refset);
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41           if (select(server_socket + 1, &refset, NULL, NULL, NULL) == -1) {
42           }
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44           ...
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46           close(server_socket);
47           modbus_free(ctx);
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SEE ALSO

50       modbus_tcp_accept(3) modbus_tcp_pi_accept(3) modbus_tcp_pi_listen(3)
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AUTHORS

53       The libmodbus documentation was written by Stéphane Raimbault
54       <stephane.raimbault@gmail.com[1]>
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NOTES

57        1. stephane.raimbault@gmail.com
58           mailto:stephane.raimbault@gmail.com
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62libmodbus 3.0.8                   07/31/2019              MODBUS_TCP_LISTEN(3)
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