C Language Socket Programming Development application Example _c language

Implementation steps:

1. Server End

Copy Code code as follows:

#include <stdio.h>//calls for functions such as printf
function calls for #include <winsock2.h>//socket
#pragma comment (lib, "ws2_32")//C language References other class libraries, in addition to the. h file, add the corresponding lib file (this is different from C #)

Copy Code code as follows:

int main ()
{
Wsadata Wsadata;
WSAStartup (Makeword (2, 2), &wsadata);

SOCKET S=socket (pf_inet, Sock_stream, ipproto_tcp);

Sockaddr_in sockaddr;
Sockaddr.sin_family=pf_inet;
Sockaddr.sin_addr. S_un.   S_ADDR=INET_ADDR ("127.0.0.1"); Which IP address is required to bind to the local
Sockaddr.sin_port=htons (9000); Ports that need to be tapped
Bind (S, (sockaddr*) &sockaddr, sizeof (SOCKADDR)); Make binding action

Listen (s, 1); Start listening

printf ("Listening on port [%d].\n", 9000);

while (TRUE)
{
SOCKADDR clientaddr;
int size=sizeof (SOCKADDR);

SOCKET Clientsocket;
Clientsocket=accept (S, &clientaddr, &size); Block until a new TCP client connection is available
printf ("***sys*** New client touched.\n");

char* msg= "Hello, my client.\r\n";
Send (Clientsocket, MSG, strlen (msg) +sizeof (char), NULL); The third parameter here is to note that a char length is added to the
printf ("***sys*** hello.\n");

while (TRUE)
{
Char buffer[maxbyte]={0};
Recv (clientsocket, buffer, maxbyte, NULL); Receive send operation for client socket all the time
printf ("***client***%s\n", buffer);
}

Closesocket (Clientsocket); Close socket
}

Closesocket (s); Turn off listening sockets

WSACleanup (); Unloading

GetChar ();

Exit (0);
}

Because it is still learning, so there is no multithreading, so the client can actually only 1, the others will be blocked outside

About the socket buffer is also a bit learned, such as the end of the end of the \ r \ n, and so on, there are reasons, suggest to look at the data.

2. Client Side

Copy Code code as follows:

#include <stdio.h>//call for input and output functions, printf, gets
#include <winsock2.h>//socket header files
#include <Windows.h>//In order to facilitate debugging, so joined the wait 2 seconds to connect to the server, where the sleep function

#pragma comment (lib, "ws2_32")//socket library file

Copy Code code as follows:

int main ()
{
Sleep (2000); Sleep for 2 seconds and connect to the server

Wsadata Wsadata;
WSAStartup (Makeword (2, 2), &wsadata);

SOCKET S=socket (pf_inet, Sock_stream, ipproto_tcp);

Sockaddr_in sockaddr;
Sockaddr.sin_family=pf_inet;
Sockaddr.sin_addr. S_un. S_ADDR=INET_ADDR ("127.0.0.1");
Sockaddr.sin_port=htons (9000);

Connect (S, (sockaddr*) &sockaddr, sizeof (SOCKADDR));

Char buffer[maxbyte]={0};
Recv (s, buffer, maxbyte, NULL);
printf ("***server***%s", buffer);

while (TRUE)
{
char* Mymsg=new char[100000];
printf ("Can chat with server now:\n");
Gets (mymsg);
Send (S, mymsg, strlen (mymsg) +sizeof (char), NULL);
/*
The Bufferlength parameter in the RECV function can be fixed to a value
The Bufferlength parameter in the Send function cannot be fixed to a value, it needs to look at the actual length and takes into account the ' I ' string
*/
}

Closesocket (s);

WSACleanup ();

GetChar ();

Exit (0);
}