C++ INET 菜鸟，我做错了什么？

Question

#include <iostream>
#include <stdlib.h>
#include <stdio.h>
#include <netinet/in.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <string.h>
#include <cstdio>

using namespace std;

int main(int argc, char *argv[])
{
  int port, n,sockfd;
  struct sockaddr_in srv_addr;
  struct hostent *serv;

  char buffer[256];

  if(argc<3)
  {
    cout <<"\n ussage: host port\nexiting\n";
    return 0;
  }

  port=atoi(argv[2]);

  sockfd=socket(AF_INET, SOCK_STREAM, 0);

  if (sockfd < 0)
  {
    cout <<"\nsocket creation on"<<port<<" failed\nexiting\ncheck to see if port is in use";
    return 0;
  }

  serv = gethostbyname(argv[1]);

  if (serv=NULL)
  {
    cout <<"\n"<<serv<<" is not a valid host name\nexiting";
    return 0;
  }

  bzero((char *) &srv_addr, sizeof(srv_addr));

  srv_addr.sin_family=AF_INET;

  bcopy((char *) serv->h_addr, 
        (char *) &srv_addr.sin_addr.s_addr,
                 serv->h_length);

  srv_addr.sin_port=htons(port); 
  if (connect(sockfd,&srv_addr,
               sizeof (srv_addr))<0)
  {
    cout <<" \nconnection failed\n";
  }

  cout <<"\nType message\n";

  bzero(buffer, 256);

  cin.getline(buffer,256);

  n=write(sockfd,buffer,strlen(buffer));
  if (n>0)
  {
    cout <<"\nsocket write error\nexiting\n";
  }

  n=read(sockfd,buffer,255);


  if (n>0)
  {
    cout <<"\nsocket read error\nexiting\n";
  }           

  cout <<buffer;

  return 0;
}

编译时出现错误:

fg.c: In function ‘int main(int, char**)’:
fg.c:53:33: error: cannot convert ‘sockaddr_in*’ to ‘const sockaddr*’ for argument ‘2’ to ‘int connect(int, const sockaddr*, socklen_t)’

我想不通。我是编程的菜鸟。任何帮助都将不胜感激。

Answer 1

你需要显式转换。替换

connect(sockfd,&srv_addr, sizeof (srv_addr))

与

connect(sockfd,(sockaddr*)&srv_addr, sizeof (srv_addr))