/* GNU's uptime.
   Copyright (C) 92, 93, 94, 95, 96, 1997, 1998 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/* Written by jla; revised by djm */

#include <config.h>
#include <getopt.h>

#include "error.h"
#include "readutmp.h"
#include "system.h"

/* The name this program was run with. */
char *program_name;

/* If nonzero, display usage information and exit.  */
static int show_help;

/* If nonzero, print the version on standard output and exit.  */
static int show_version;

static struct option const longopts[] =
{
  {"help", no_argument, &show_help, 1},
  {"version", no_argument, &show_version, 1},
  {NULL, 0, NULL, 0}
};

static void
print_uptime (int n, const STRUCT_UTMP *this)
{
  register int entries = 0;
  time_t boot_time = 0;
  time_t time_now;
  time_t uptime = 0;
  int updays;
  int uphours;
  int upmins;
  struct tm *tmn;
  double avg[3];
  int loads;
#ifdef HAVE_PROC_UPTIME
  FILE *fp;
  double upsecs;

  fp = fopen ("/proc/uptime", "r");
  if (fp != NULL)
    {
      char buf[BUFSIZ];
      int res;
      fgets (buf, BUFSIZ, fp);
      res = sscanf (buf, "%lf", &upsecs);
      if (res == 1)
	uptime = (time_t) upsecs;
      fclose (fp);
    }
#endif /* HAVE_PROC_UPTIME */
  /* Loop through all the utmp entries we just read and count up the valid
     ones, also in the process possibly gleaning boottime. */
  while (n--)
    {
      if (this->ut_name[0]
#ifdef USER_PROCESS
	  && this->ut_type == USER_PROCESS
#endif
	  )
	{
	  ++entries;
	}
      /* If BOOT_MSG is defined, we can get boottime from utmp.  This avoids
	 possibly needing special privs to read /dev/kmem. */
#ifdef BOOT_MSG
# if HAVE_PROC_UPTIME
      if (uptime == 0)
# endif /* HAVE_PROC_UPTIME */
	if (!strcmp (this->ut_line, BOOT_MSG))
	  boot_time = UT_TIME_MEMBER (this);
#endif /* BOOT_MSG */
      ++this;
    }
  time_now = time (0);
#if defined HAVE_PROC_UPTIME
  if (uptime == 0)
#endif
    {
      if (boot_time == 0)
	error (1, errno, _("couldn't get boot time"));
      uptime = time_now - boot_time;
    }
  updays = uptime / 86400;
  uphours = (uptime - (updays * 86400)) / 3600;
  upmins = (uptime - (updays * 86400) - (uphours * 3600)) / 60;
  tmn = localtime (&time_now);
  printf (_(" %2d:%02d%s  up "), ((tmn->tm_hour % 12) == 0
				  ? 12 : tmn->tm_hour % 12),
	  /* FIXME: use strftime, not am, pm.  Uli reports that
	     the german translation is meaningless.  */
	  tmn->tm_min, (tmn->tm_hour < 12 ? _("am") : _("pm")));
  if (updays > 0)
    printf ("%d %s,", updays, (updays == 1 ? _("day") : _("days")));
  printf (" %2d:%02d,  %d %s", uphours, upmins, entries,
	  (entries == 1) ? _("user") : _("users"));

#if defined (HAVE_GETLOADAVG) || defined (C_GETLOADAVG)
  loads = getloadavg (avg, 3);
#else
  loads = -1;
#endif

  if (loads == -1)
    putchar ('\n');
  else
    {
      if (loads > 0)
	printf (_(",  load average: %.2f"), avg[0]);
      if (loads > 1)
	printf (", %.2f", avg[1]);
      if (loads > 2)
	printf (", %.2f", avg[2]);
      if (loads > 0)
	putchar ('\n');
    }
}

/* Display the system uptime and the number of users on the system,
   according to utmp file FILENAME. */

static void
uptime (const char *filename)
{
  int n_users;
  STRUCT_UTMP *utmp_buf;
  int fail = read_utmp (filename, &n_users, &utmp_buf);

  if (fail)
    error (1, errno, "%s", filename);

  print_uptime (n_users, utmp_buf);
}

static void
usage (int status)
{
  if (status != 0)
    fprintf (stderr, _("Try `%s --help' for more information.\n"),
	     program_name);
  else
    {
      printf (_("Usage: %s [OPTION]... [ FILE ]\n"), program_name);
      printf (_("\
Output who is currently logged in according to FILE.\n\
If FILE is not specified, use %s.  %s as FILE is common.\n\
\n\
      --help        display this help and exit\n\
      --version     output version information and exit\n"),
	      UTMP_FILE, WTMP_FILE);
      puts (_("\nReport bugs to <sh-utils-bugs@gnu.org>."));
    }
  exit (status);
}

int
main (int argc, char **argv)
{
  int optc, longind;
  program_name = argv[0];
  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  while ((optc = getopt_long (argc, argv, "", longopts, &longind)) != -1)
    {
      switch (optc)
	{
	case 0:
	  break;

	default:
	  usage (1);
	}
    }

  if (show_version)
    {
      printf ("uptime (%s) %s\n", GNU_PACKAGE, VERSION);
      exit (0);
    }

  if (show_help)
    usage (0);

  switch (argc - optind)
    {
    case 0:			/* uptime */
      uptime (UTMP_FILE);
      break;

    case 1:			/* uptime <utmp file> */
      uptime (argv[optind]);
      break;

    default:			/* lose */
      error (0, 0, _("too many arguments"));
      usage (1);
    }

  exit (0);
}