login/logout.c

   1 /* Copyright (C) 1996-2021 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <string.h>
  21 #include <utmp.h>
  22 #include <time.h>
  23 #include <sys/time.h>
  24
  25 int
  26 logout (const char *line)
  27 {
  28   struct utmp tmp, utbuf;
  29   struct utmp *ut;
  30   int result = 0;
  31
  32   /* Tell that we want to use the UTMP file.  */
  33   if (utmpname (_PATH_UTMP) == -1)
  34     return 0;
  35
  36   /* Open UTMP file.  */
  37   setutent ();
  38
  39   /* Fill in search information.  */
  40   tmp.ut_type = USER_PROCESS;
  41   strncpy (tmp.ut_line, line, sizeof tmp.ut_line);
  42
  43   /* Read the record.  */
  44   if (getutline_r (&tmp, &utbuf, &ut) >= 0)
  45     {
  46       /* Clear information about who & from where.  */
  47       memset (ut->ut_name, '\0', sizeof ut->ut_name);
  48       memset (ut->ut_host, '\0', sizeof ut->ut_host);
  49
  50       struct __timespec64 ts;
  51       __clock_gettime64 (CLOCK_REALTIME, &ts);
  52       TIMESPEC_TO_TIMEVAL (&ut->ut_tv, &ts);
  53       ut->ut_type = DEAD_PROCESS;
  54
  55       if (pututline (ut) != NULL)
  56         result = 1;
  57     }
  58
  59   /* Close UTMP file.  */
  60   endutent ();
  61
  62   return result;
  63 }