UDP und select()

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <fcntl.h>

#include <string.h>

#include <sys/mman.h>

#include <signal.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include "at91rm9200.h"

#define LPT_SERVER_IP 192.168.0.1

#define LPT_SERVER_PORT 5000

volatile u32 *pPIO_BASE;

char Page[]="Hello World";

int Char_position=0;

int Send=0;

char *szServer="192.168.0.1";

short nPort=LPT_SERVER_PORT;

int Client(void)  //Rückgabewert 0 wenn Selbsttest in Ordnung

{

//1. Einen Socket erstellen

int theSocket=0, Send_Test=0, ServerLen=0, nRet=0;

struct sockaddr_in saServer;

char Answer[256];

//AF_INET = Protokollfamilie  SOCK_DGRAM = UDP Datagramm Socket

theSocket=socket(AF_INET, SOCK_DGRAM, 0);

if (theSocket < 0) {

    printf("Creating socket... failed\n");

    return(1);

  }

else{

  printf("Creating socket... OK\n");

  }

//2. C Struktur mit Adressen füllen

saServer.sin_family= AF_INET;

saServer.sin_port= htons(nPort);

saServer.sin_addr.s_addr= inet_addr(szServer);

//3. Daten senden

Send_Test= sendto(theSocket, Page, strlen(Page), 0, &saServer, sizeof

(struct sockaddr));

if(Send_Test < 0){

  perror("sendto");

  printf("Error sending data\n");

  close(theSocket);

  return(1);

  }

//4. Warten auf Antwort vom Sender

memset(Answer, 0, sizeof(Answer));

ServerLen= sizeof(struct sockaddr);

nRet= recvfrom(theSocket, Answer, sizeof(Answer), 0, (struct sockaddr

*)&saServer, &ServerLen);

printf("Address %s answered: %s\n", inet_ntoa(saServer.sin_addr),

Answer);

//5. Socket beenden

close(theSocket);

return(0);

}

int main (void)

{

int result=1;

result=Client();

return (result);

}