다중 클라이언트 처리 서버

#include <stdio.h>
#include <winsock2.h>
 
#pragma comment(lib, "wsock32.lib")
 
char buff[255];
int len = 0;
int val;
 
DWORD WINAPI thread(LPVOID socket)
{
	SOCKET cs = (SOCKET)socket;
	struct sockaddr_in client;
	int size = sizeof(client);
	getpeername(cs, (struct sockaddr*)&client, &size);
 
	while(1)
	{
		memset(&buff, 0, sizeof(buff));
		printf("command : ");
		if(fgets(buff, 255, stdin) == NULL)
		{
			printf("Command Failure...\n");
			continue;
		}
 
		len = strlen(buff);
		if(len == 1)
		{
			printf("Please reenter the command...\n");
			continue;
		}
		else if(buff[len-1] == '\n') buff[len-1] = '\0';
 
		if(!strcmp(buff, "dir"))
		{
			printf("adf");
			printf("Connected Client [ IP : %s / port : %d ]\n", inet_ntoa(client.sin_addr), ntohs(client.sin_port));
		}
 
 
		len = strlen(buff);
		val = send(cs, buff, len, 0);
		if(val == -1)
		{
			printf("Data transmission failure\n");
			break;
		}
		else if(val == 0) break;
	}
 
	if(closesocket(cs) == 0)
	{
		printf("Client End [ IP : %s / port : %d ]\n", inet_ntoa(client.sin_addr), ntohs(client.sin_port));
	}
	return 0;
}
 
int main(int argc, char *argv[])
{
	while(1)
	{
		cs = accept(s, (struct sockaddr*)&client, &size);
		if(cs == INVALID_SOCKET)
		{
			printf("Client connection failure...\n");
			closesocket(s);
			WSACleanup();
			return -1;
		}
 
		printf("Connected Client [ IP : %s / Port : %d ]\n", inet_ntoa(client.sin_addr), ntohs(client.sin_port));
 
		HANDLE thread1 = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)thread, (LPVOID)cs, 0, NULL);
		if(thread1 == NULL)
		{
			printf("Create Thread Error\n");
			break;
		}
	} //while문 종료