message SimpleMessage {    required int32 lucky_number = 1;}

#include <stdio.h>#include <pb_encode.h>#include <pb_decode.h>#include "simple.pb.h"int main(){    /* This is the buffer where we will store our message. */    uint8_t buffer[128];    size_t message_length;    bool status;        /* Encode our message */    {        /* Allocate space on the stack to store the message data.         *         * Nanopb generates simple struct definitions for all the messages.         * - check out the contents of simple.pb.h!         * It is a good idea to always initialize your structures         * so that you do not have garbage data from RAM in there.         */        SimpleMessage message = SimpleMessage_init_zero;                /* Create a stream that will write to our buffer. */        pb_ostream_t stream = pb_ostream_from_buffer(buffer, sizeof(buffer));                /* Fill in the lucky number */        message.lucky_number = 13;                /* Now we are ready to encode the message! */        status = pb_encode(&stream, SimpleMessage_fields, &message);        message_length = stream.bytes_written;                /* Then just check for any errors.. */        if (!status)        {            printf("Encoding failed: %s\n", PB_GET_ERROR(&stream));            return 1;        }    }        /* Now we could transmit the message over network, store it in a file or     * wrap it to a pigeon‘s leg.     */    /* But because we are lazy, we will just decode it immediately. */        {        /* Allocate space for the decoded message. */        SimpleMessage message = SimpleMessage_init_zero;                /* Create a stream that reads from the buffer. */        pb_istream_t stream = pb_istream_from_buffer(buffer, message_length);                /* Now we are ready to decode the message. */        status = pb_decode(&stream, SimpleMessage_fields, &message);                /* Check for errors... */        if (!status)        {            printf("Decoding failed: %s\n", PB_GET_ERROR(&stream));            return 1;        }                /* Print the data contained in the message. */        printf("Your lucky number was %d!\n", message.lucky_number);    }        return 0;}