getgrent.c revision 1573 
1/*
2 * Copyright (c) 1989, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#if defined(LIBC_SCCS) && !defined(lint)
35static char sccsid[] = "@(#)getgrent.c	8.2 (Berkeley) 3/21/94";
36#endif /* LIBC_SCCS and not lint */
37
38#include <sys/types.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <grp.h>
42
43static FILE *_gr_fp;
44static struct group _gr_group;
45static int _gr_stayopen;
46static int grscan(), start_gr();
47
48#define	MAXGRP		200
49static char *members[MAXGRP];
50#define	MAXLINELENGTH	1024
51static char line[MAXLINELENGTH];
52
53struct group *
54getgrent()
55{
56	if (!_gr_fp && !start_gr() || !grscan(0, 0, NULL))
57		return(NULL);
58	return(&_gr_group);
59}
60
61struct group *
62getgrnam(name)
63	const char *name;
64{
65	int rval;
66
67	if (!start_gr())
68		return(NULL);
69	rval = grscan(1, 0, name);
70	if (!_gr_stayopen)
71		endgrent();
72	return(rval ? &_gr_group : NULL);
73}
74
75struct group *
76#ifdef __STDC__
77getgrgid(gid_t gid)
78#else
79getgrgid(gid)
80	gid_t gid;
81#endif
82{
83	int rval;
84
85	if (!start_gr())
86		return(NULL);
87	rval = grscan(1, gid, NULL);
88	if (!_gr_stayopen)
89		endgrent();
90	return(rval ? &_gr_group : NULL);
91}
92
93static
94start_gr()
95{
96	if (_gr_fp) {
97		rewind(_gr_fp);
98		return(1);
99	}
100	return((_gr_fp = fopen(_PATH_GROUP, "r")) ? 1 : 0);
101}
102
103int
104setgrent()
105{
106	return(setgroupent(0));
107}
108
109int
110setgroupent(stayopen)
111	int stayopen;
112{
113	if (!start_gr())
114		return(0);
115	_gr_stayopen = stayopen;
116	return(1);
117}
118
119void
120endgrent()
121{
122	if (_gr_fp) {
123		(void)fclose(_gr_fp);
124		_gr_fp = NULL;
125	}
126}
127
128static
129grscan(search, gid, name)
130	register int search, gid;
131	register char *name;
132{
133	register char *cp, **m;
134	char *bp;
135	char *fgets(), *strsep(), *index();
136
137	for (;;) {
138		if (!fgets(line, sizeof(line), _gr_fp))
139			return(0);
140		bp = line;
141		/* skip lines that are too big */
142		if (!index(line, '\n')) {
143			int ch;
144
145			while ((ch = getc(_gr_fp)) != '\n' && ch != EOF)
146				;
147			continue;
148		}
149		_gr_group.gr_name = strsep(&bp, ":\n");
150		if (search && name && strcmp(_gr_group.gr_name, name))
151			continue;
152		_gr_group.gr_passwd = strsep(&bp, ":\n");
153		if (!(cp = strsep(&bp, ":\n")))
154			continue;
155		_gr_group.gr_gid = atoi(cp);
156		if (search && name == NULL && _gr_group.gr_gid != gid)
157			continue;
158		cp = NULL;
159		for (m = _gr_group.gr_mem = members;; bp++) {
160			if (m == &members[MAXGRP - 1])
161				break;
162			if (*bp == ',') {
163				if (cp) {
164					*bp = '\0';
165					*m++ = cp;
166					cp = NULL;
167				}
168			} else if (*bp == '\0' || *bp == '\n' || *bp == ' ') {
169				if (cp) {
170					*bp = '\0';
171					*m++ = cp;
172			}
173				break;
174			} else if (cp == NULL)
175				cp = bp;
176		}
177		*m = NULL;
178		return(1);
179	}
180	/* NOTREACHED */
181}
182