#include <stdio.h>
#include <stdlib.h>
#include <netdb.h>
#include <netinet/in.h>
#include <string.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(0);
portno = atoi(argv[2]);
sockfd = socket(AF_INET, SOCK_STREAM, 0);
perror("ERROR opening socket");
exit(1);
server = gethostbyname(argv[1]);
if (server == NULL)
fprintf(stderr,"ERROR, no such host\n");
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)
printf("Please enter the message: ");
bzero(buffer,256);
fgets(buffer,255,stdin);
n = write(sockfd, buffer, strlen(buffer));
if (n < 0)
perror("ERROR writing to socket");
n = read(sockfd, buffer, 255);
printf("%s\n",buffer);
return 0;
portno = 5001;
serv_addr.sin_addr.s_addr = INADDR_ANY;
if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0)
listen(sockfd,5);
clilen = sizeof(cli_addr);
newsockfd = accept(sockfd, (struct sockaddr *)&cli_addr, &clilen);
if (newsockfd < 0)
bzero(buffer,256);
AF_INET