#include "main.h"

// $ ./prog02_udp_send_txt 127.0.0.1 2000
// hello
//======================================================================
//						MAIN
//======================================================================
int main(int argc, char **argv)
{	
	int ok;
	int portNumber;
	int32_t value;
	char msg[0x100];
	struct sockaddr_in toAddr;
	
	//---- check command line arguments ----
	if(argc!=3) { fprintf(stderr,"usage: %s destination port\n",argv[0]); exit(1); }

	//---- extract destination IP address ----
	struct hostent *host=gethostbyname(argv[1]);
								if(!host) { fprintf(stderr,"unknown host %s\n",argv[1]); exit(1); }
	
	in_addr_t ipAddress=*((in_addr_t *)(host->h_addr));

	//---- extract destination port number ----
	if(sscanf(argv[2],"%d",&portNumber)!=1)
								{ fprintf(stderr,"invalid port %s\n",argv[2]); exit(1); }

	//---- create UDP socket ----
	int udpSocket=socket(PF_INET,SOCK_DGRAM,0);
								if(udpSocket==-1) { perror("socket"); exit(1); }
	// ... allowing broadcast (optional)
	int on=1;
	ok = setsockopt(udpSocket,SOL_SOCKET,SO_BROADCAST,&on,sizeof(int));
								if( ok == -1) { perror("setsockopt"); exit(1); }

	for(;;)
	  {
		  //---- read next line on standard input ----
		  if(!fgets(msg,0x100,stdin)) { break; } // [Control]+[d] --> EOF
		  
		    //---- extract 32-bit integer ----
		  if(sscanf(msg,"%d",&value)!=1) continue;

		  //---- convert to network format 32-bit integer ----
		  value=htonl(value);

		  //---- send message to the specified destination/port ----
		  toAddr.sin_family=AF_INET;
		  toAddr.sin_port=htons(portNumber);
		  toAddr.sin_addr.s_addr=ipAddress;
		  ok = sendto(udpSocket,&value,4,0,(struct sockaddr *)&toAddr,sizeof(toAddr)); 
								if( ok == -1){ perror("sendto"); exit(1); }
	  }

	close(udpSocket);
	
return 0;
}
//^^^^^^^^^^^^^^^^^^^^^^^^^^ EOF ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^