#include <stdio.h>     
#include <sys/socket.h> 
#include <arpa/inet.h>  
#include <stdlib.h>    
#include <string.h>    
#include <unistd.h> 

void DieWithError(char *errorMessage)
{
    perror(errorMessage);
    exit(1);
}


int main(int argc, char *argv[]) {

    int sock;                         
    struct sockaddr_in broadcastAddr;
    char *broadcastIP;                
    unsigned short broadcastPort;     
    char *sendString;                 
    int broadcastPermission;         
    unsigned int sendStringLen;       

    broadcastIP = "0.0.0.0";           
    broadcastPort = 6741;    
    sendString = "Hello World!";
    printf("start\n");

    printf("Socket is about to be created!\n");
    if ( (sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0 ) { 
        perror("socket creation failed"); 
        exit(EXIT_FAILURE); 
    } 
    printf("Socket is created! \n");

    broadcastPermission = 1;
    if (setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (void *) &broadcastPermission, 
          sizeof(broadcastPermission)) < 0)
        DieWithError("setsockopt() failed");

    memset(&broadcastAddr, 0, sizeof(broadcastAddr));   
    broadcastAddr.sin_family = AF_INET;                 
    broadcastAddr.sin_addr.s_addr = inet_addr(broadcastIP);
    broadcastAddr.sin_port = htons(broadcastPort);         

    sendStringLen = strlen(sendString);

for (;;) 
    {
         if (sendto(sock, sendString, sendStringLen, 0, (struct sockaddr *) 
               &broadcastAddr, sizeof(broadcastAddr)) != sendStringLen)
             DieWithError("sendto() sent a different number of bytes than expected");

        sleep(3);   
    }

   return 0;
}