login/setutent_r.c

   1 /* Copyright (C) 1996 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 Library General Public License as
   7 published by the Free Software Foundation; either version 2 of the
   8 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 Library General Public License for more details.
  14
  15 You should have received a copy of the GNU Library General Public
  16 License along with the GNU C Library; see the file COPYING.LIB.  If
  17 not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18 Boston, MA 02111-1307, USA.  */
  19
  20 #include <fcntl.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <utmp.h>
  25
  26 /* This is the default name.  */
  27 static const char default_utmp_name[] = _PATH_UTMP;
  28
  29 /* Current file name.  */
  30 static const char *utmp_file_name = (const char *) default_utmp_name;
  31
  32
  33 void
  34 __setutent_r (struct utmp_data *utmp_data)
  35 {
  36   /* Before the UTMP_DATA is used before the first time the UT_FD
  37      field must be set to -1.  */
  38   if (utmp_data->ut_fd == -1)
  39     {
  40       utmp_data->ut_fd = open (utmp_file_name, O_RDWR);
  41       if (utmp_data->ut_fd == -1)
  42         {
  43           /* Hhm, read-write access did not work.  Try read-only.  */
  44           utmp_data->ut_fd = open (utmp_file_name, O_RDONLY);
  45           if (utmp_data->ut_fd == -1)
  46             {
  47               perror (_("while opening UTMP file"));
  48               return;
  49             }
  50         }
  51     }
  52
  53   /* Remember we are at beginning of file.  */
  54   utmp_data->loc_utmp = 0;
  55 #if _HAVE_UT_TYPE - 0
  56   utmp_data->ubuf.ut_type = UT_UNKNOWN;
  57 #endif
  58 }
  59 weak_alias (__setutent_r, setutent_r)
  60
  61
  62 int
  63 __utmpname (const char *file)
  64 {
  65   char *fname = __strdup (file);
  66   if (fname == NULL)
  67     return 0;
  68
  69   if (utmp_file_name != default_utmp_name)
  70     free ((void *) utmp_file_name);
  71
  72   utmp_file_name = fname;
  73
  74   return 1;
  75 }
  76 weak_alias (__utmpname, utmpname)