sock_getip.c

Linux大学上机源码学习

#include <errno.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <stdlib.h>
void init_sockaddr(struct sockaddr_in *name,char *addr,char *serv)
{ 
    name->sin_family=AF_INET;
    name->sin_addr.s_addr=inet_addr(addr);
    if (serv==NULL)
       name->sin_port=htons(0);
    else
       name->sin_port=htons(atoi(serv));
}
int socket_connect(char *hostname,char *serv_port)
  {
    int sockfd;
    struct sockaddr_in sockaddr;
    struct hostent *hp;
    char *host,myname[104];
    /* init the IP and port of server*/
    init_sockaddr(&sockaddr,hostname,serv_port);
    if((sockfd=socket(AF_INET,SOCK_STREAM,0))<0){
          printf("socket create error\n");
          exit(0);
     }       
   if((connect(sockfd,(struct sockaddr *)&sockaddr,sizeof(sockaddr)))<0){
          printf("cann't connect server%s\n",strerror(errno));
          exit(0);
   }
    return(sockfd);
 }
int main(int argc,char **argv)
  { 
    int sockfd,n;
    char recvbuff[256],*host;
    static char xx[10]="asdfa";
    struct sockaddr_in servaddr;
    if(argc<2)
      host="127.0.0.1";
    else 
      host=argv[1];
   sockfd=socket_connect(host,"2003");
   write(sockfd,xx,sizeof(xx));
   while((n=read(sockfd,recvbuff,256))>0){
      recvbuff[n]=0;
      printf("receve data is:%s",recvbuff);
   }
  if(n<0){
     printf("read error");
     exit(0);
  }
  return 0;
}