#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h> 

void error(char *msg)
{
    perror(msg);
    exit(0);
}

int main(int argc, char *argv[])
{
    int sockfd, portno, n;

    struct sockaddr_in serv_addr;
    struct hostent *server;

    char buffer[256];
    if (argc < 3) {
       fprintf(stderr,"usage %s hostname port\n", argv[0]);
       exit(0);
    }

    /* create socket, get sockfd handle */

    portno = atoi(argv[2]);
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) 
        error("ERROR opening socket");

    /* fill in server address in sockaddr_in datastructure */

    server = gethostbyname(argv[1]);
    if (server == NULL) {
        fprintf(stderr,"ERROR, no such host\n");
        exit(0);
    }
    bzero((char *) &serv_addr, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    bcopy((char *)server->h_addr, 
         (char *)&serv_addr.sin_addr.s_addr,
         server->h_length);
    serv_addr.sin_port = htons(portno);

    /* connect to server */

    if (connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) < 0) 
        error("ERROR connecting");

    /* ask user for input */

    while(1) {
      printf("Please enter the message: ");
      bzero(buffer,256);
      fgets(buffer,255,stdin);
      
      /* send user message to server */
      
      n = write(sockfd,buffer,strlen(buffer));
      if (n < 0) 
	error("ERROR writing to socket");
      bzero(buffer,256);
      
      /* read reply from server */
      
      n = read(sockfd,buffer,255);
      if (n < 0) 
	error("ERROR reading from socket");
      printf("%s\n",buffer);
    }
    return 0;
}