client.c

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

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(1);
    }
    
    portno = atoi(argv[2]);
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if(sockfd < 0) 
    {
        fprintf(stderr, "Error opening socket.\n");
        exit(1);
    }
        
    server = gethostbyname(argv[1]);
    if(server == NULL) 
    {
        fprintf(stderr,"ERROR, no such host\n");
        exit(1);
    }
    
    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);
    
    if(connect(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) 
    {
        fprintf(stderr, "Error connecting.\n");
        exit(1);
    }
    
    while(true)
    {
        printf("Please enter the message: ");
        bzero(buffer, 256);
        fgets(buffer, 255, stdin);
        n = write(sockfd, buffer, strlen(buffer));
        if(n < 0)
        {
            fprintf(stderr, "Error writing.\n");
            exit(1);
        }
        bzero(buffer, 256);
        n = read(sockfd, buffer, 255);
        if(n < 0)
        {
            fprintf(stderr, "Error reading.\n");
            exit(1);
        }
        printf("%s\n", buffer);
        
        if (_kbhit()) 
        {
            key = _getch();
            if (key == 'e');
            {
                break;   
            }
        }
    }
    
    return 0;
}