/* client process */
#include <ctype.h>
#include <sys/types.h>
#include <sys/socket.h> 
#include <netinet/in.h>
#define SIZE sizeof(struct sockaddr_in)
main(int argvc, char ** argv){
int sockfd;
char c,*addr;
/* the local port on the client */
struct sockaddr_in client = {AF_INET, INADDR_ANY, INADDR_ANY};
/* the remote address of the server */
struct sockaddr_in server = {AF_INET, 7000,INADDR_ANY};
 addr=*++argv;
 printf("connecting to address %s\n",addr);
/* convert and store the server's IP address */
  server.sin_addr.s_addr = inet_addr(addr) ;
/* set up the transport end point */
  if ( (sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
     perror("socket call failed");
     exit(1);
  }
/* bind the local address to the end point */
  if ( bind(sockfd, (struct sockaddr *)&client, SIZE) == -1){
    perror ("bind call failed") ;
    exit(1);
  }
/* read a character from the keyboard */
  while( read(0, &c, 1) != 0){
/* send the character to the server */
    if( sendto(sockfd, &c, 1, 0,(struct sockaddr *) &server, SIZE) == -1){
      perror("client: sending");
      continue;
    }
/* receive the message back */
   if(recv(sockfd, &c, 1, 0)== -1){
     perror("client: receiving");
     continue;
   }
   write(1, &c, 1);
  }
}