MINGW中的套接字程序挂起

Question

这是我的套接字程序：

#include<stdio.h>
#include<winsock2.h>

int main(int argc , char *argv[])
{
    WSADATA wsa;
    SOCKET s;
    struct sockaddr_in server;
    printf("\nInitialising Winsock...");
    if (WSAStartup(MAKEWORD(2,2),&wsa) != 0)
    {
        printf("Failed. Error Code : %d",WSAGetLastError());
        return 1;
    }
    printf("Initialised.\n");
    //Create a socket
    if((s = socket(AF_INET , SOCK_STREAM , 0 )) == INVALID_SOCKET)
    {
        printf("Could not create socket : %d" , WSAGetLastError());
    }
    printf("Socket created.\n");

    server.sin_addr.s_addr = inet_addr("192.168.31.151");
    server.sin_family = AF_INET;
    server.sin_port = htons( 80 );

    //Connect to remote server
    if (connect(s , (struct sockaddr *)&server , sizeof(server)) < 0)
    {
        puts("connect error");
        return 1;
    }
    puts("Connected");

    return 0;
}

我尝试使用此命令使用MINGW编译器进行编译：

gcc.exe a.cpp -lws2_32

运行后它不打印任何东西。它只是挂起。我错过了什么？