// tb.c - text based web browser
// Usage: tb hostname page (for example www.yahoo.com /index.html )

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>  // alarm()
#include <sys/types.h>
#include <sys/socket.h>  // socket()
#include <netinet/in.h>  // htons(), struct in_addr
#include <netdb.h>  // struct hostent

int main(int argc, char **argv) {
  struct sockaddr_in s;
  struct hostent *h;
  int fd;
  char buf[1024];
  int n;

  if (argc < 3) {
    fprintf(stderr, "To read web page: tb hostname /page (tb www.yahoo.com /index.html)\n");
    exit(1);
  }
  alarm(5);  // die after 5 seconds
  fd = socket(AF_INET, SOCK_STREAM, 0);
  if (fd < 0)
    perror("socket"), exit(1);
  s.sin_family = AF_INET;
  s.sin_port = htons(80);  // port 80 is HTTP
  h = gethostbyname(argv[1]);  // DNS lookup
  if (!h)
    perror(argv[1]), exit(1);  // unknown host
  s.sin_addr.s_addr = ((struct in_addr*)(h->h_addr))->s_addr;
  if (connect(fd, (struct sockaddr*)&s, sizeof(s)) < 0) 
    perror("connect"), exit(1);
  write(fd, "GET ", 4);  // request web page using old HTTP 0.9 protocol
  write(fd, argv[2], strlen(argv[2]));
  write(fd, "\r\n", 2);
  while ((n = read(fd, buf, 1024)) > 0)  // read response, copy to stdout
    write(1, buf, n);
  close(fd);
  return 0;
}