c语言实现端口扫描程序

  

   向指定的ip和端口发起请求，若该ip端口出于工作状态，则能成功连接，不能则说明端口已关闭。

#include <string.h>
#include <Winsock2.h>

#define DEST_IP "127.0.0.1"

#define DEST_PORT 1434

int main()
{
//初始化WinSock
WORD wVersionRequested = MAKEWORD(2,2);
WSADATA wsaData;
if(WSAStartup(wVersionRequested,&wsaData) != 0)
{
printf("初始化WinSock失败！\n") ;
return 0 ;
}

int sockfd,n;

struct sockaddr_in dest_addr;

sockfd = socket(AF_INET, SOCK_STREAM, 0);

dest_addr.sin_family = AF_INET;

dest_addr.sin_port = htons(DEST_PORT);

dest_addr.sin_addr.s_addr = inet_addr(DEST_IP);

//bzero(&(dest_addr.sin_zero));
n=connect(sockfd, (struct sockaddr *)&dest_addr, sizeof(struct sockaddr));
if(n==-1){
printf("端口没有开启");
}else{
printf("端口开启");
}
}

具体的socket,connect函数及用法参考http://blog.sina.com.cn/s/blog_79b01f66010163q3.html