glibc/login/utmpname.c

77 lines
2.0 KiB
C

/* Copyright (C) 1997-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 1997.
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
<http://www.gnu.org/licenses/>. */
#include <bits/libc-lock.h>
#include <stdlib.h>
#include <string.h>
#include <utmp.h>
#include "utmp-private.h"
/* This is the default name. */
static const char default_file_name[] = _PATH_UTMP;
/* Current file name. */
const char *__libc_utmp_file_name = (const char *) default_file_name;
/* We have to use the lock in getutent_r.c. */
__libc_lock_define (extern, __libc_utmp_lock attribute_hidden)
int
__utmpname (const char *file)
{
int result = -1;
__libc_lock_lock (__libc_utmp_lock);
/* Close the old file. */
(*__libc_utmp_jump_table->endutent) ();
__libc_utmp_jump_table = &__libc_utmp_unknown_functions;
if (strcmp (file, __libc_utmp_file_name) != 0)
{
if (strcmp (file, default_file_name) == 0)
{
free ((char *) __libc_utmp_file_name);
__libc_utmp_file_name = default_file_name;
}
else
{
char *file_name = __strdup (file);
if (file_name == NULL)
/* Out of memory. */
goto done;
if (__libc_utmp_file_name != default_file_name)
free ((char *) __libc_utmp_file_name);
__libc_utmp_file_name = file_name;
}
}
result = 0;
done:
__libc_lock_unlock (__libc_utmp_lock);
return result;
}
weak_alias (__utmpname, utmpname)