sendto.c

linux下的人机对话编程

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
	struct sockaddr_in pin_s;
	struct hostent *server_host_name_s;

void init_port(int port)
    {
      bzero(&pin_s,sizeof(pin_s));
      pin_s.sin_family=AF_INET;
      pin_s.sin_addr.s_addr=htonl(INADDR_ANY);
      pin_s.sin_addr.s_addr=((struct in_addr*)(server_host_name_s->h_addr))->s_addr;
      pin_s.sin_port=htons(port);
   }

int Sendto(char * host_name_s,char *str,int size)
 {
	int port1=8090;
	int port2=8095;
	int port;
	char buf[8192]={};
	str[size]='\0';
      int socket_descriptor;
      int errorcount1=1,recount1=1;
      int errorcount2=1,recount2=1;
      int errorcount3=1,recount3=1;
      int errorcount4=1,recount4=1;
      int errorcount5=1,recount5=1;
      int export_flag=0;
     if(export_flag==0)
        {while(errorcount1<=3)
           {
            if((server_host_name_s=gethostbyname(host_name_s))==0)
               errorcount1++;
             else { port=port1;
                    break;
                  }
           }
          if(errorcount1==4)
           {
                 port=port2;
              export_flag=1;
           }
        }
	init_port(port);
       if(export_flag==1)
        {while(recount1<=3)
              {
            if((server_host_name_s=gethostbyname(host_name_s))==0)
               recount1++;
             else  break;
           }
        if(recount1==4)
           {
              printf("Error resolving local host\n");
             return -1;
            }
       }
 if(export_flag==0)
        {while(errorcount2<=3)
           {
             if((socket_descriptor=socket(AF_INET,SOCK_STREAM,0))==-1)
               errorcount2++;
             else  break;
           }
          if(errorcount2==4)
           {
              port=port2;
              export_flag=1;
  }
          }
        init_port(port);
      if(export_flag==1)
        {while(recount2<=3)
           {
             if((socket_descriptor=socket(AF_INET,SOCK_STREAM,0))==-1)
                 recount2++;
             else  break;
          }
          if(recount2==4)
           {
              printf("Error create socket\n");
                   return -1;
            }
        }
    if(export_flag==0)
        {while(errorcount3<=3)
           {
             if(connect(socket_descriptor,(void*)&pin_s,sizeof(pin_s))==-1)
               errorcount3++;
             else  break;
          }
          if(errorcount3==4)
          {
              port=port2;
              export_flag=1;
            }
          }
	init_port(port);
       if(export_flag==1)
        {while(recount3<=3)
           {
               if(connect(socket_descriptor,(void*)&pin_s,sizeof(pin_s))==-1)
                 recount3++;
               else  break;
        }
          if(recount3==4)
           {
              printf("Error connecting  socket\n");
                   return -1;
            }
        }
     if(export_flag==0)
        {while(errorcount4<=3)
           {
              if(send(socket_descriptor,str,size,0)==-1)
             errorcount4++;
              else  break;
           }
          if(errorcount4==4)
             {
              port=port2;
              export_flag=1;
            }
          }
	init_port(port);
    if(export_flag==1)
        {while(recount4<=3)
           {
              if(send(socket_descriptor,str,size,0)==-1)
               recount4++;
               else  break;
           }
          if(recount4==4)
           {
              printf("Error in send\n");
                   return -1;
            }
        }
     if(export_flag==0)
        {while(errorcount5<=3)
           {
              if(recv(socket_descriptor, buf, 8192, 0)==-1)
               errorcount5++;
             else  break;
           }
           if(errorcount5==4)
           {
              port=port2;
              export_flag=1;
            }
          }
	init_port(port);
      if(export_flag==1)
        {while(recount5<=3)
           {
               if(recv(socket_descriptor, buf, 8192, 0)==-1)
                 recount5++;
               else  break;
                                                                                                               
           }
         if(recount5==4)
           {
              printf("Error in receive\n");
                   return -1;
            }
        }
printf("success!\n");
            printf("Response form server:%s\n",buf);
      close(socket_descriptor);
  return 0;
   }