Send（）和recv（）为double或int

Question

I have problem with send and recv double/int from client to server and server to client. For this moment, I have:

client:

cin>>xp;
send( master,(char*)&xp,sizeof(xp),0);

server:

int valread, nr;
char * buffer;   
valread = recv(s,(char *)&nr,sizeof(buffer),0);

and it's work, but when i send from server to client i do something wrong.

I have on server:

int lol;
lol=5;
send(s, (char*)&lol, sizeof(lol), 0);

And I want this int on client:

bytesRecv = recv(master,(char*)&nr,sizeof(buffer),0);

I don't knwo why it doesn't work :/ When I cout/printf this int on client it's 0 or 9,2555... Please help :/

Answer 1

Your sizeof(buffer) is wrong - you should send and receive a sizeof(int) .

Also, note this will not work if your server and client store integers in different order in memory - their Endianness may be different.

To make sure this is not a problem, switch from host to network order and back. Read about htonl and ntohl