/* utmpdump - dump utmp-like files.
   Copyright (C) 1997-2025 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <utmp.h>

static void
print_entry (struct utmp *up)
{
  /* Mixed 32-/64-bit systems may have timeval structs of different sixe
     but need struct utmp to be the same size.  So in 64-bit up->ut_tv may
     not be a timeval but a struct of __int32_t's.  This would cause a compile
     time warning and a formatting error when 32-bit int is passed where
     a 64-bit long is expected. So copy up->up_tv to a temporary timeval.
     This is 32-/64-bit agnostic and expands the timeval fields to the
     expected size as needed. */
  struct timeval temp_tv;
  temp_tv.tv_sec = up->ut_tv.tv_sec;
  temp_tv.tv_usec = up->ut_tv.tv_usec;

  printf ("[%d] [%05d] [%-4.4s] [%-8.8s] [%-12.12s] [%-16.16s] [%-15.15s]"
	  " [%ld]\n",
	  up->ut_type, up->ut_pid, up->ut_id, up->ut_user, up->ut_line,
	  up->ut_host, 4 + ctime (&temp_tv.tv_sec),
	  (long int) temp_tv.tv_usec);
}

int
main (int argc, char *argv[])
{
  struct utmp *up;

  if (argc > 1)
    utmpname (argv[1]);

  setutent ();

  while ((up = getutent ()))
    print_entry (up);

  endutent ();

  return EXIT_SUCCESS;
}
