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[glibc.git] / login / utmpname.c
blob875dbd59732aeb0c5ea28a61a7c2244ded28b8f4
1 /* Copyright (C) 1997, 2002 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 1997.
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.
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.
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. */
20 #include <bits/libc-lock.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <utmp.h>
25 #include "utmp-private.h"
28 /* This is the default name. */
29 static const char default_file_name[] = _PATH_UTMP;
31 /* Current file name. */
32 const char *__libc_utmp_file_name = (const char *) default_file_name;
34 /* We have to use the lock in getutent_r.c. */
35 __libc_lock_define (extern, __libc_utmp_lock attribute_hidden)
38 int
39 __utmpname (const char *file)
41 int result = -1;
43 __libc_lock_lock (__libc_utmp_lock);
45 /* Close the old file. */
46 (*__libc_utmp_jump_table->endutent) ();
47 __libc_utmp_jump_table = &__libc_utmp_unknown_functions;
49 if (strcmp (file, __libc_utmp_file_name) != 0)
51 if (strcmp (file, default_file_name) == 0)
53 if (__libc_utmp_file_name != default_file_name)
54 free ((char *) __libc_utmp_file_name);
56 __libc_utmp_file_name = default_file_name;
58 else
60 char *file_name = __strdup (file);
61 if (file_name == NULL)
62 /* Out of memory. */
63 goto done;
65 if (__libc_utmp_file_name != default_file_name)
66 free ((char *) __libc_utmp_file_name);
68 __libc_utmp_file_name = file_name;
72 result = 0;
74 done:
75 __libc_lock_unlock (__libc_utmp_lock);
76 return result;
78 weak_alias (__utmpname, utmpname)