1: /* Copyright (C) 1997, 2002, 2006 Free Software Foundation, Inc.
    2:    This file is part of the GNU C Library.
    3:    Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 1997.
    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, write to the Free
   17:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   18:    02111-1307 USA.  */
   19: 
   20: #include <bits/libc-lock.h>
   21: #include <stdlib.h>
   22: #include <string.h>
   23: #include <utmp.h>
   24: 
   25: #include "utmp-private.h"
   26: 
   27: 
   28: /* This is the default name.  */
   29: static const char default_file_name[] = _PATH_UTMP;
   30: 
   31: /* Current file name.  */
   32: const char *__libc_utmp_file_name = (const char *) default_file_name;
   33: 
   34: /* We have to use the lock in getutent_r.c.  */
   35: __libc_lock_define (extern, __libc_utmp_lock attribute_hidden)
   36: 
   37: 
   38: int
   39: __utmpname (const char *file)
   40: {
   41:   int result = -1;
   42: 
   43:   __libc_lock_lock (__libc_utmp_lock);
   44: 
   45:   /* Close the old file.  */
   46:   (*__libc_utmp_jump_table->endutent) ();
   47:   __libc_utmp_jump_table = &__libc_utmp_unknown_functions;
   48: 
   49:   if (strcmp (file, __libc_utmp_file_name) != 0)
   50:     {
   51:       if (strcmp (file, default_file_name) == 0)
   52:         {
   53:           free ((char *) __libc_utmp_file_name);
   54: 
   55:           __libc_utmp_file_name = default_file_name;
   56:         }
   57:       else
   58:         {
   59:           char *file_name = __strdup (file);
   60:           if (file_name == NULL)
   61:             /* Out of memory.  */
   62:             goto done;
   63: 
   64:           if (__libc_utmp_file_name != default_file_name)
   65:             free ((char *) __libc_utmp_file_name);
   66: 
   67:           __libc_utmp_file_name = file_name;
   68:         }
   69:     }
   70: 
   71:   result = 0;
   72: 
   73: done:
   74:   __libc_lock_unlock (__libc_utmp_lock);
   75:   return result;
   76: }
   77: weak_alias (__utmpname, utmpname)