=================

#include "stdlib.h"
#include "winsock2.h"

#pragma comment(lib, "ws2_32.lib")

SOCKET			g_socket;
ULONG			g_timeout;
sockaddr_in		g_addrLocal;
sockaddr_in		g_addrRemote;

void help()
{
	printf("Connection checking test programm.\n\n");
	printf("TEST -r remote_address [-p port_no] [-l local_address] [-t timeout]\n");
	printf("-r remote_address		remote server address\n");
	printf("-p port_no			remote server port address\n");
	printf("-l local_address		local IP address\n");
	printf("-t timeout			connection waiting timeout in milliseconds\n\n");
	printf("sample :\n");
	printf("TEST -r www.microsoft.com -p 80 -l 195.128.0.1 -t 2000\n\n");
}

void Init()
{
	WSADATA wd;
	WSAStartup(MAKEWORD(2, 2), &wd);

	g_socket = INVALID_SOCKET;
	g_timeout= 0xFFFFFFFF;
	memset(&g_addrLocal, 0, sizeof(sockaddr_in));
	memset(&g_addrRemote, 0, sizeof(sockaddr_in));

	g_addrRemote.sin_addr.s_addr = INADDR_NONE;
	g_addrRemote.sin_family	= AF_INET;
	g_addrLocal.sin_addr.s_addr  = INADDR_NONE;
	g_addrLocal.sin_family = AF_INET;
}

void Exit()
{
	WSACleanup();

	if (g_socket != INVALID_SOCKET)
	{
		closesocket(g_socket);
		g_socket = INVALID_SOCKET;
	}
}

BOOL GetAddress(char* szAddress, sockaddr_in *sockAddr)
{
	if (szAddress == NULL|sockAddr == NULL)
		return NULL;

	ULONG nAddr = inet_addr(szAddress);
	if (nAddr == INADDR_NONE)
	{
		hostent *host = gethostbyname(szAddress);
		if (host == NULL)
			return FALSE;

		nAddr = *((ULONG *)host->h_addr);
	}

	sockAddr->sin_addr.s_addr = nAddr;

	return (nAddr != INADDR_NONE);
}

BOOL ValidateArgs(int argc, char* argv[])
{
	if (argc < 3)
		return FALSE;

	char *szRemoteAddr = NULL;
	char *szLocalAddr  = NULL;
	char *port = NULL;
	char *timeout = NULL;

	char *pch;

	for (int i = 1; i < argc; i ++)
	{
		pch = argv[i];
		if (*pch == '-'|*pch == '/')
		{
			pch ++;

			switch (*pch)
			{
			case	'r':
				szRemoteAddr = argv[i + 1];
				if (*szRemoteAddr != '-' && *szRemoteAddr != '/')
				{
					i ++;
					if (!GetAddress(szRemoteAddr, &g_addrRemote))
						return FALSE;
				}
				break;

			case	'p':
				port = argv[i + 1];
				if (*port != '-' && *port != '/')
				{
					i ++;
					g_addrRemote.sin_port = htons((u_short)atoi(port));
				}
				break;

			case	'l':
				szLocalAddr = argv[i + 1];
				if (*szLocalAddr != '-' && *szLocalAddr != '/')
				{
					i ++;
					if (!GetAddress(szLocalAddr, &g_addrLocal))
						return FALSE;
				}
				break;

			case	't':
				timeout = argv[i + 1];
				if (*timeout != '-' && *timeout != '/')
				{
					i ++;
					g_timeout = (u_long)atol(timeout);
				}
				break;

			default:
				return FALSE;

			}
		}
	}

	if (g_addrRemote.sin_port == 0)
		g_addrRemote.sin_port = htons(80);

	return (g_addrRemote.sin_addr.s_addr != INADDR_NONE);
}

BOOL CreateSocket()
{
	g_socket = socket(AF_INET, SOCK_STREAM, 0);
	if (g_addrLocal.sin_addr.s_addr != INADDR_NONE)
		return (bind(g_socket, (sockaddr*)&g_addrLocal, sizeof(sockaddr_in)) != SOCKET_ERROR);
	else
		return (g_socket != INVALID_SOCKET);

}

BOOL Connect()
{
	if (g_socket == INVALID_SOCKET)
		return FALSE;

	u_long block = 1;
	if (ioctlsocket(g_socket, FIONBIO, &block) == SOCKET_ERROR)
		return FALSE;


	fd_set	writefds;
	FD_ZERO(&writefds);
	FD_SET(g_socket, &writefds);
	
	TIMEVAL	timeout = {(long)(g_timeout / 1000), (long)(g_timeout - (g_timeout / 1000) * 1000)};

	int err;
	connect(g_socket, (sockaddr*)&g_addrRemote, sizeof(sockaddr_in));
	err = select(0, NULL, &writefds, NULL, g_timeout != 0xFFFFFFFF ? &timeout : NULL);

	if (err == SOCKET_ERROR)
		return FALSE;
	else if (err == 0)
		printf("connetion is not established, due timeout.\n");
	else
		printf("connection establised\n");

	return TRUE;
}

int main(int argc, char* argv[])
{
	Init();

	if (!ValidateArgs(argc, argv))
		help();
	else if (!CreateSocket()|!Connect())
		printf("error established during programm running.\n");

	Exit();

	printf("\npress any key to exit programm.\n");
	getchar();
	return 0;
}

#include "stdlib.h" 
#include "winsock2.h" 

#pragma comment(lib, "ws2_32.lib") 

SOCKET g_socket; 
ULONG g_timeout; 
sockaddr_in g_addrLocal; 
sockaddr_in g_addrRemote; 

void help() 
{ 
    printf("Connection checking test programm.\n\n"); 
    printf("TEST -r remote_address [-p port_no] [-l local_address] [-t timeout]\n"); 
    printf("-r remote_address remote server address\n"); 
    printf("-p port_no remote server port address\n"); 
    printf("-l local_address local IP address\n"); 
    printf("-t timeout connection waiting timeout in milliseconds\n\n"); 
    printf("sample :\n"); 
    printf("TEST -r www.microsoft.com -p 80 -l 195.128.0.1 -t 2000\n\n"); 
} 

void Init() 
{ 
    WSADATA wd; 
    WSAStartup(MAKEWORD(2, 2), &wd); 

    g_socket = INVALID_SOCKET; 
    g_timeout= 0xFFFFFFFF; 
    memset(&g_addrLocal, 0, sizeof(sockaddr_in)); 
    memset(&g_addrRemote, 0, sizeof(sockaddr_in)); 

    g_addrRemote.sin_addr.s_addr = INADDR_NONE; 
    g_addrRemote.sin_family = AF_INET; 
    g_addrLocal.sin_addr.s_addr = INADDR_NONE; 
    g_addrLocal.sin_family = AF_INET; 
} 

void Exit() 
{ 
    WSACleanup(); 

    if (g_socket != INVALID_SOCKET) {
        closesocket(g_socket); 
        g_socket = INVALID_SOCKET; 
    }
} 

BOOL GetAddress(char* szAddress, sockaddr_in *sockAddr) 
{ 
    if (szAddress == NULL|sockAddr == NULL)
        return NULL;

    ULONG nAddr = inet_addr(szAddress); 
    if (nAddr == INADDR_NONE) {
        hostent *host = gethostbyname(szAddress); 
        if (host == NULL)
            return FALSE;

        nAddr = *((ULONG *)host->h_addr); 
    }

    sockAddr->sin_addr.s_addr = nAddr; 

    return(nAddr != INADDR_NONE); 
} 

BOOL ValidateArgs(int argc, char* argv[]) 
{ 
    if (argc < 3)
        return FALSE;

    char *szRemoteAddr = NULL; 
    char *szLocalAddr = NULL; 
    char *port = NULL; 
    char *timeout = NULL; 

    char *pch; 

    for (int i = 1; i < argc; i ++) {
        pch = argv[i]; 
        if (*pch == '-'|*pch == '/') {
            pch ++; 

            switch (*pch) {
            case 'r': 
                szRemoteAddr = argv[i + 1]; 
                if (*szRemoteAddr != '-' && *szRemoteAddr != '/') {
                    i ++; 
                    if (!GetAddress(szRemoteAddr, &g_addrRemote))
                        return FALSE;
                }
                break; 

            case 'p': 
                port = argv[i + 1]; 
                if (*port != '-' && *port != '/') {
                    i ++; 
                    g_addrRemote.sin_port = htons((u_short)atoi(port)); 
                }
                break; 

            case 'l': 
                szLocalAddr = argv[i + 1]; 
                if (*szLocalAddr != '-' && *szLocalAddr != '/') {
                    i ++; 
                    if (!GetAddress(szLocalAddr, &g_addrLocal))
                        return FALSE;
                }
                break; 

            case 't': 
                timeout = argv[i + 1]; 
                if (*timeout != '-' && *timeout != '/') {
                    i ++; 
                    g_timeout = (u_long)atol(timeout); 
                }
                break; 

            default: 
                return FALSE; 

            } 
        }
    } 

    if (g_addrRemote.sin_port == 0)
        g_addrRemote.sin_port = htons(80);

    return(g_addrRemote.sin_addr.s_addr != INADDR_NONE); 
} 

BOOL CreateSocket() 
{ 
    g_socket = socket(AF_INET, SOCK_STREAM, 0); 
    if (g_addrLocal.sin_addr.s_addr != INADDR_NONE)
        return(bind(g_socket, (sockaddr*)&g_addrLocal, sizeof(sockaddr_in)) != SOCKET_ERROR);
    else
        return(g_socket != INVALID_SOCKET); 

} 

BOOL Connect() 
{ 
    if (g_socket == INVALID_SOCKET)
        return FALSE;

    u_long block = 1; 
    if (ioctlsocket(g_socket, FIONBIO, &block) == SOCKET_ERROR)
        return FALSE;


    fd_set writefds; 
    FD_ZERO(&writefds); 
    FD_SET(g_socket, &writefds); 

    TIMEVAL timeout = {(long)(g_timeout / 1000), (long)(g_timeout - (g_timeout / 1000) * 1000)}; 

    int err; 
    connect(g_socket, (sockaddr*)&g_addrRemote, sizeof(sockaddr_in)); 
    err = select(0, NULL, &writefds, NULL, g_timeout != 0xFFFFFFFF ? &timeout : NULL); 

    if (err == SOCKET_ERROR)
        return FALSE;
    else if (err == 0)
        printf("connetion is not established, due timeout.\n");
    else
        printf("connection establised\n"); 

    return TRUE; 
} 

int main(int argc, char* argv[]) 
{ 
    Init(); 

    if (!ValidateArgs(argc, argv))
        help();
    else if (!CreateSocket()|!Connect())
        printf("error established during programm running.\n");

    Exit(); 

    printf("\npress any key to exit programm.\n"); 
    getchar(); 
    return 0;
}