void unpack_from_file()
{
FILE *fp = NULL;
char buf[MAX_LEN];
int sum, total;
AMessage *amsg = NULL;
if (NULL == (fp = fopen(FILE_NAME, "r"))) {
fprintf(stderr, "fopen failed");
exit(-1);
}
total = 0;
while (0 < (sum = fread(buf+total, 1, MAX_LEN, fp))) {
total += sum;
if (total >= MAX_LEN) {
fprintf(stderr, "read more than MAX_LEN");
exit(-1);
}
}
if (NULL == (amsg = amessage__unpack(NULL, total, buf))) {
fprintf(stderr, "amessage__unpack failed");
exit(-1);
}
printf("amsg->a = %d\n", amsg->a);
if(amsg->has_b) {
printf("amsg->b = %d\n", amsg->b);
}
amessage__free_unpacked(amsg, NULL);
fclose(fp);
}
int main (int argc, const char * argv[])
{
AMessage *msg;
// Read packed message from standard-input.
uint8_t buf[MAX_MSG_SIZE];
size_t msg_len = read_buffer (MAX_MSG_SIZE, buf);
// Unpack the message using protobuf-c.
msg = amessage__unpack(NULL, msg_len, buf);
if (msg == NULL)
{
fprintf(stderr, "error unpacking incoming message\n");
exit(1);
}
// display the message's fields.
printf("Received: a=%d",msg->a); // required field
if (msg->has_b) // handle optional field
printf(" b=%d",msg->b);
printf("\n");
// Free the unpacked message
amessage__free_unpacked(msg, NULL);
return 0;
}