1 #include <stdio.h>
2 #include <pb_encode.h>
3 #include <pb_decode.h>
4 #include "simple.pb.h"
5 
6 int main()
7 {
8     /* This is the buffer where we will store our message. */
9     uint8_t buffer[128];
10     size_t message_length;
11     bool status;
12 
13     /* Encode our message */
14     {
15         /* Allocate space on the stack to store the message data.
16          *
17          * Nanopb generates simple struct definitions for all the messages.
18          * - check out the contents of simple.pb.h!
19          * It is a good idea to always initialize your structures
20          * so that you do not have garbage data from RAM in there.
21          */
22         SimpleMessage message = SimpleMessage_init_zero;
23 
24         /* Create a stream that will write to our buffer. */
25         pb_ostream_t stream = pb_ostream_from_buffer(buffer, sizeof(buffer));
26 
27         /* Fill in the lucky number */
28         message.lucky_number = 13;
29         message.unlucky.number = 42;
30 
31         /* Now we are ready to encode the message! */
32         status = pb_encode(&stream, SimpleMessage_fields, &message);
33         message_length = stream.bytes_written;
34 
35         /* Then just check for any errors.. */
36         if (!status)
37         {
38             printf("Encoding failed: %s\n", PB_GET_ERROR(&stream));
39             return 1;
40         }
41     }
42 
43     /* Now we could transmit the message over network, store it in a file or
44      * wrap it to a pigeon's leg.
45      */
46 
47     /* But because we are lazy, we will just decode it immediately. */
48 
49     {
50         /* Allocate space for the decoded message. */
51         SimpleMessage message = SimpleMessage_init_zero;
52 
53         /* Create a stream that reads from the buffer. */
54         pb_istream_t stream = pb_istream_from_buffer(buffer, message_length);
55 
56         /* Now we are ready to decode the message. */
57         status = pb_decode(&stream, SimpleMessage_fields, &message);
58 
59         /* Check for errors... */
60         if (!status)
61         {
62             printf("Decoding failed: %s\n", PB_GET_ERROR(&stream));
63             return 1;
64         }
65 
66         /* Print the data contained in the message. */
67         printf("Your lucky number was %d!\n", message.lucky_number);
68         printf("Your unlucky number was %u!\n", message.unlucky.number);
69     }
70 
71     return 0;
72 }
73 
74