Sending character 0 over network
Author
Hi, I am using an external network library, which is called ENet.I mostly completed the data transmission.I would like to send x,y coordinates over it, I am using 2 chars for this.I get the coordinate with inline function (a*256+b) on the other side.However if a char is 0 then everything collapses after that.It's not a problem like it stops reading, because I get it char by char.However as I said data gets strange after that.
I am thinking of increasing a and b by 1 but that will cause error too when coord. is for example 255.
What should I do? Is it a problem of ENet(when getting data from the buffer), but thats not wise because it sends the size of packets within every packet.Any help would be appreciated, thanks =)
Please don't mark threads 'solved' in this forum. --jpetrie
[Edited by - jpetrie on May 4, 2009 8:56:28 PM]
Show the exact code where you pass your data to send to ENet, and the opposite snippet where you read the data from ENet.
Author
They are not the problem I am quite sure, because I checked the string that server is sending, and I only do
string bilgi = event.packet->data
by client and the results are as I said(again I saw it by debugging).
But if you want to check
That means that ENet is able to determine the size of the package but can't continue to read data after char 0, and it just continues to write 0 till the packet end.I guess that this is a problem about ENet, but I don't know how to solve..
btw ustring is "typedef basic_string<unsigned char> ustring;" because packets should contain unsigned chars according to ENet.But this works great without 0's..
Again Thanks.
string bilgi = event.packet->data
by client and the results are as I said(again I saw it by debugging).
But if you want to check
ENetPacket* Komut(unsigned char komut,unsigned int ID,int type,int takim,int x,int y){ // Player Yarat ustring mesaj; uchar x1,x2,y1,y2; x2 = x%256; x1 = (x-x2)/256; y2 = y%256; y1 = (y-y2)/256; mesaj += (unsigned char)komut; mesaj += (unsigned char)ID; mesaj += type; mesaj += takim; mesaj += x1; mesaj += x2; mesaj += y1; mesaj += y2;// I checked mesaj, and it is obviously fine .. ENetPacket * packet = enet_packet_create (mesaj.c_str(),mesaj.length() + 1, ENET_PACKET_FLAG_RELIABLE); return packet;}if(mNetwork->GetEvent()){ ENetEvent* event = &mNetwork->event; ustring bilgi; switch (event->type) { case ENET_EVENT_TYPE_CONNECT: printf ("A new client connected from %x:%u.\n", event->peer -> address.host,event->peer -> address.port); break; case ENET_EVENT_TYPE_RECEIVE: bilgi = event->packet->data;// I debug here and see //that data doesn't "continue" after the 0 character, that I looked by the //server side.It's just full of 0's with the count of packet size after the //first 0 character.look below*://...... //That means that ENet is able to determine the size of the package but can't continue to read data after char 0, and it just continues to write 0 till the packet end.I guess that this is a problem about ENet, but I don't know how to solve..
btw ustring is "typedef basic_string<unsigned char> ustring;" because packets should contain unsigned chars according to ENet.But this works great without 0's..
Again Thanks.
What is the data type of event->packet->data? If it's const unsigned char* or something like that, then assigning from there into the ustring will lose the data after the first zero byte, because C++ doesn't know to use the length information from the packet to assign the string.
To fix that, you can do something like
To fix that, you can do something like
case ENET_EVENT_TYPE_RECEIVE: bilgi.assign(event->packet->data, event->packet->length);
Zahlman's got it already.
Whenever you assing a (const) char* to a std::string the string class tries to read all characters up to a 0. If a 0 is part of the chain then the string class doesn't know.
Whenever you assing a (const) char* to a std::string the string class tries to read all characters up to a 0. If a 0 is part of the chain then the string class doesn't know.
Author
Oh gee, it is working perfectly now ! If I had known how to do this my uniqueID's ,teamnumbers and slotnumbers would start from 0, but now they are starting from 1.
.
Anyway it doesn't matter thank you all for your help =)
exact code should be;
.
Anyway it doesn't matter thank you all for your help =)
exact code should be;
bilgi.assign(event->packet->data,event->packet->dataLength);
You might also consider whether a std::vector<char> might be a better choice of container for received data than a std::string. :)
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