void handle2(int signo) 
{ 
     printf("signal number: %d\n",signo); 
    return; 
} 

main(int argc,char **argv) 

 { 
   int sockfd,newsockfd,cli_len; 
   struct sockaddr_in cli_addr,serv_addr; 
   int maxseg,sendbufsize,recvbufsize,optlen; 
   int bufsize; 
   int ret; 
   struct servent *sp;          // point of services 
   char command[500]; 
   char hostname[34]; 

    

  // Open a socket of TCP(an internet stream socket) 

   signal(SIGALRM,handle2); 
   signal(SIGINT,handle2); 
   signal(SIGABRT,handle2); 
   signal(SIGFPE,handle2); 
   signal(SIGSEGV,handle2); 

        gethostname(hostname,34); 
if ((sockfd=socket(AF_INET,SOCK_STREAM,0))<0) 
    err_dump("server: can't open stream socket!"); 

  // Bind our local address so that the clint can connect to us 

  bzero((char*)&serv_addr,sizeof(serv_addr)); 
  serv_addr.sin_family=AF_INET; 
  serv_addr.sin_addr.s_addr =htonl(INADDR_ANY); 
  if((sp=getservbyname("rtereset","tcp"))==NULL){ 
      perror("tcp_init:unkown service\n"); 
      return(-1); 
      } 
  serv_addr.sin_port=sp->s_port; 

   bufsize=131072; 
  if(setsockopt(sockfd,SOL_SOCKET,SO_SNDBUF,&bufsize,sizeof(bufsize))<0) 
   { 
    perror("tcp_init setopt err:"); 
     return(-1); 
   } 
  if(setsockopt(sockfd,SOL_SOCKET,SO_RCVBUF,&bufsize,sizeof(bufsize))<0) 
   { 
    perror("tcp_init setopt err:"); 
     return(-1); 
   } 

 if(setsockopt(sockfd,SOL_SOCKET,SO_REUSEADDR,&bufsize,sizeof(bufsize))<0) 
   { 
       perror("tcp_init setopt err:"); 
       return -1; 
   } 
 if(setsockopt(sockfd,SOL_SOCKET,SO_REUSEPORT,&bufsize,sizeof(bufsize))<0) 
      { 
       perror("tcp_init setopt err:"); 
       return -1; 
   } 


  if (bind(sockfd, 
          (struct sockaddr *)&serv_addr, 
          sizeof(struct sockaddr_in))<0) 
     { 
        err_dump("server: can't bind local address!"); 
        return(-1); 
     } 
  listen(sockfd,8); 

  for(;;){ 
        // waiting for connection from clint process. 
        newsockfd=accept(sockfd, 
                        (struct sockaddr *)&cli_addr, 
                        &cli_len); 
        if (newsockfd<0)     //  Here it returned IP 0.0.0.0 and no error report. 
         { 
          if (errno == EINTR) 
               continue; 
           else 
           err_dump("server :accept error!"); 
             return(-1); 
         } 
       ret=recv(newsockfd,(char *)command ,500,0); 
        if (ret < 0) 
           { 
             err_dump("server : recv error!"); 
             return -1; 
           } 
   } 
 close(sockfd); 
        close(newsockfd); 
  }