winsock sending message error

[chazzy69]

Hey im making a client/server program using winsocks, i have managed to connect the client to server but when i try to send a message from the client to the server, the message doesn't make it correctly.

I have tested the message before i sent it to see if its correct and the length, it seems fine but when i check it on the server prog its not even the same length, let alone readable.

This is the code im using to send the message (normal plain text) from the client

char buffer[256]; 
ZeroMemory(buffer, 256);
strcpy(buffer, ("This is the message"));
 
nret = send(theSocket, buffer, strlen(buffer), 0);
 

This is the code im using to Receive the message, oh yer before this the server waits for a connection before reciving.

char buffer[256]; 
int p;
 
nret = recv(listeningSocket, buffer, p, 0);
 
 

If found this code on jonnie winsock tutorial.

[weaknessforcats]

Did you test nret that the message was sent properly?

Did you test nret that the message was received properly?

[chazzy69]

Hey sorry about getting back to the msg so late iv being away for a while, anyhow how would i go about testing nret for properly sent and properly received message.

Any help is appreciated

[mac11]

send and recv should return the number of bytes sent or received or -1 (at least on my system) for error

[chazzy69]

SO far i have just being using strlen(buffer) to find the length of the sent message and received message and they have being vastly different.

Can you give a quick example on how to return the number of bytes sent and received by send and recv?

Thanks for any help

[weaknessforcats]

Can you give a quick example on how to return the number of bytes sent and received by send and recv?

How about you post your calls to send and recv so I can see what you are doing. Then I can comment.

I assume you are aware that these functions return the number of bytes sent or received and that -1 means there was an error and in that case you need to call WSAGetLastError to see what the problem was.

[chazzy69]

I have already posted my send and receive calls above (#1), also this program already has an error check for my send and receive:

if (nret == SOCKET_ERROR) {
 
return NETWORK_ERROR;
 

Wondering if maybe trying to access the buffer the wrong way because i'm just trying to do this at the moment-

cout<< buffer<< "\n"<<strlen(buffer)<<"\n";
 

This comes strait after receiving the message "

 nret = recv(listeningSocket, buffer, p, 0); 

"

Am i perhaps supposed to access buffer as part of nret????

Thanks for the help it appreciated.

[chazzy69]

Ok i just checked and im getting nret= -1, so what am i supposed to do now???

thanks

[chazzy69]

Is it possible that im getting an error because my recv is not waiting for the client to send its message?? if so how can i make it wait???


Thanks your help is greatly appreciated

[mac11]

Let me first say that my comments are based on how sockets work in linux and I don't know if things will be different for you.

Ok i just checked and im getting nret= -1, so what am i supposed to do now???

check 'errno' to see why it failed - you'll have to #include errno.h if you didn't already

 cerr << "recv failed: " << strerror( errno ); 

Is it possible that im getting an error because my recv is not waiting for the client to send its message?? if so how can i make it wait???

if recv returns -1 errno may be set to 'EAGAIN' which means that there wasn't anything there yet so try again - maybe your getting that and just don't know it.

If you're getting -1 and errno == EAGAIN have your program sleep a little and try recv again.

[weaknessforcats]

Again, I say, have you called WSAGetLastError() to see what is causing the
-1 error ???