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

int
main(int argc, char *argv[])
{
  int sock;
  struct sockaddr_in saddr;
  struct hostent *shost;
  struct servent *serv;
  char *host, buf[256];
  char *p;

  if (argc == 1) {
    if ((host = getenv("DAYTIMESERVER")) == NULL)
      host = "localhost";
  } else {
    host = argv[1];
  }

  if ((serv = getservbyname("daytime", "tcp")) == NULL) {
    fprintf(stderr, "unknown service: daytime/tcp\n");
    return EXIT_FAILURE;
  }

  memset(&saddr, 0, sizeof(saddr));
  if (isdigit(*host)) {
    saddr.sin_addr.s_addr = inet_addr(host);
    if ((shost = gethostbyaddr((char *)&saddr.sin_addr,
			       sizeof(saddr.sin_addr), AF_INET)) == NULL) {
      fprintf(stderr, "gethostbyaddr() failed.\n");
      return EXIT_FAILURE;
    }
    host = shost->h_name;
  } else {
    shost = gethostbyname(host);
    if (shost) {
      memcpy(&saddr.sin_addr, shost->h_addr, shost->h_length);
    } else {
      fprintf(stderr, "%s: host name lookup failed.\n", host);
      return EXIT_FAILURE;
    }
  }

  saddr.sin_family = AF_INET;
  saddr.sin_port = htons(serv->s_port);

  if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
    fprintf(stderr, "can't create socket.\n");
    return 1;
  }
  if (connect(sock, (struct sockaddr *)&saddr, sizeof(struct sockaddr)) < 0) {
    fprintf(stderr, "%s: unable to connect: %s\n", host, strerror(errno));
    return EXIT_FAILURE;
  }
  read(sock, buf, sizeof(buf));
  for (p = buf; *p; p++) {
    if (*p == '\n') {
      *++p = '\0';
      break;
    }
  }
  printf("%s", buf);
  close(sock);
  return EXIT_SUCCESS;
}