#include <sys/stat.h>
#include <signal.h>
#include <fcntl.h>
#include <sys/types.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <netinet/ip_var.h>
#include <netdb.h>
#include <sys/time.h>
#include <signal.h>
#ifndef NULL
#define NULL (void*)0
#endif
#ifndef INADDR_NONE
#define INADDR_NONE 0xffffffff
#endif

#define BUFSIZE 100
struct hostent *hp;
char   buff[BUFSIZE];

#define SERV_UDP_PORT 2795

main(int argc, char *argv[])
{
	int             sockfd, i, s, alen, hlen, dlen, j, k;
	long ul;
        unsigned long inaddr;
	struct sockaddr_in serv_addr;
	unsigned char   ch;
	if (argc==1) { 
		printf("USAGE: send_udpu machine@somewhere.bla.ca\n"); 
                printf("-or-   send_udpu A.B.C.D\n");
	        printf("       within concordia CS machines just machine "
		       "name is sufficient\n");	
		exit(0);
	}
	/* open socket  for UDP protocol  */

	if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
		perror("error open socket");
		exit(-1);
	}
	memset(&serv_addr, NULL, sizeof(serv_addr));
	serv_addr.sin_family = AF_INET;
        serv_addr.sin_port   = htons(SERV_UDP_PORT);
        /* First try to convert hostname as a dotted-decimal number.
         * Only if that fails do we call gethostbyname().
         */
        if ( (inaddr = inet_addr(argv[1])) != INADDR_NONE) {
                                              /* it's dotted-decimal */
                memcpy(&serv_addr.sin_addr, &inaddr, sizeof(inaddr));
        } else {
        
	        if ((hp=gethostbyname(argv[1])) == NULL){
        	        printf("Problems with this host...\n"); 
		        exit(0);
	        }
	        serv_addr.sin_addr.s_addr = inet_addr(inet_ntoa(hp->h_addr));
        }

        ul = serv_addr.sin_addr.s_addr;
	printf("sending to %s at the following addresses:\n",argv[1]);
	printf("%s\n",inet_ntoa(serv_addr.sin_addr));
	printf("======================================================\n");
	for (k = 0, s = 'A'; k < 10; k++, s++) {	/* transmit packets */
		for (i = 0; i < 26; i++)
			/* with 26 bytes of data in each packet */
			buff[i] = s + i;

		j = sendto(sockfd, buff, i, 0, (struct sockaddr *) & serv_addr,
			   sizeof(serv_addr));
		if (j != i) {
			printf("send error\n");
			exit(1);
		}
		printf("sent data %d Bytes\n", j);
                sleep(1);
	}
}