libc: Remove some unneeded inclusions of <sys/cdefs.h>.
[dragonfly.git] / lib / libc / gen / utmp.c
CommitLineData
59a92d18
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1/* $NetBSD: utmp.c,v 1.8 2009/01/11 02:46:27 christos Exp $ */
2
3/*-
4 * Copyright (c) 2002 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christos Zoulas.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
59a92d18
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31
32#include "namespace.h"
33#include <sys/types.h>
34#include <sys/param.h>
35#include <stdio.h>
36#include <string.h>
37#include <time.h>
38#include <utmp.h>
39#include <sys/stat.h>
40
41static struct utmp utmp;
42static FILE *ut;
43static char utfile[MAXPATHLEN] = _PATH_UTMP;
44
45void
46setutent(void)
47{
48 if (ut == NULL)
49 return;
50 (void)fseeko(ut, (off_t)0, SEEK_SET);
51}
52
53struct utmp *
54getutent(void)
55{
56 if (ut == NULL) {
57 struct stat st;
58 off_t numentries;
59 if ((ut = fopen(utfile, "r")) == NULL)
60 return NULL;
61 if (fstat(fileno(ut), &st) == -1)
62 goto out;
63 /*
64 * If we have a an old version utmp file bail.
65 */
66 numentries = st.st_size / sizeof(utmp);
67 if ((off_t)(numentries * sizeof(utmp)) != st.st_size)
68 goto out;
69 }
70 if (fread(&utmp, sizeof(utmp), 1, ut) == 1)
71 return &utmp;
72out:
73 (void)fclose(ut);
74 return NULL;
75}
76
77void
78endutent(void)
79{
80 if (ut != NULL) {
81 (void)fclose(ut);
82 ut = NULL;
83 }
84}
85
86int
87utmpname(const char *fname)
88{
89 size_t len = strlen(fname);
90
91 if (len >= sizeof(utfile))
92 return 0;
93
94 /* must not end in x! */
95 if (fname[len - 1] == 'x')
96 return 0;
97
98 (void)strlcpy(utfile, fname, sizeof(utfile));
99 endutent();
100 return 1;
101}