minix/lib/libc/gen/utmp.c

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/* $NetBSD: utmp.c,v 1.10 2011/10/15 23:00:02 christos Exp $ */
/*-
* Copyright (c) 2002 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: utmp.c,v 1.10 2011/10/15 23:00:02 christos Exp $");
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <sys/types.h>
#include <sys/param.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <utmp.h>
#include <sys/stat.h>
static struct utmp utmp;
static FILE *ut;
static char utfile[MAXPATHLEN] = _PATH_UTMP;
void
setutent(void)
{
if (ut == NULL)
return;
(void)fseeko(ut, (off_t)0, SEEK_SET);
}
struct utmp *
getutent(void)
{
if (ut == NULL) {
struct stat st;
off_t numentries;
if ((ut = fopen(utfile, "re")) == NULL)
return NULL;
if (fstat(fileno(ut), &st) == -1)
goto out;
/*
* If we have a an old version utmp file bail.
*/
numentries = st.st_size / sizeof(utmp);
if ((off_t)(numentries * sizeof(utmp)) != st.st_size)
goto out;
}
if (fread(&utmp, sizeof(utmp), 1, ut) == 1)
return &utmp;
out:
(void)fclose(ut);
return NULL;
}
void
endutent(void)
{
if (ut != NULL) {
(void)fclose(ut);
ut = NULL;
}
}
int
utmpname(const char *fname)
{
size_t len = strlen(fname);
if (len >= sizeof(utfile))
return 0;
/* must not end in x! */
if (fname[len - 1] == 'x')
return 0;
(void)strlcpy(utfile, fname, sizeof(utfile));
endutent();
return 1;
}