getgrent.c revision 1.1 
1/*	$NetBSD: getgrent.c,v 1.1 1995/10/08 23:08:48 gwr Exp $	*/
2
3/*
4 * Copyright (c) 1989, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 * Portions Copyright (c) 1994, Jason Downs. All Rights Reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37
38#include <sys/types.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <string.h>
42#include <grp.h>
43
44
45static FILE *_gr_fp;
46static struct group _gr_group;
47static int _gr_stayopen;
48static int grscan(), start_gr();
49
50#define	MAXGRP		200
51static char *members[MAXGRP];
52#define	MAXLINELENGTH	1024
53static char line[MAXLINELENGTH];
54
55
56struct group *
57getgrent()
58{
59	if (!_gr_fp && !start_gr() || !grscan(0, 0, NULL))
60		return(NULL);
61	return(&_gr_group);
62}
63
64struct group *
65getgrnam(name)
66	const char *name;
67{
68	int rval;
69
70	if (!start_gr())
71		return(NULL);
72	rval = grscan(1, 0, name);
73	if (!_gr_stayopen)
74		endgrent();
75	return(rval ? &_gr_group : NULL);
76}
77
78struct group *
79#ifdef __STDC__
80getgrgid(gid_t gid)
81#else
82getgrgid(gid)
83	gid_t gid;
84#endif
85{
86	int rval;
87
88	if (!start_gr())
89		return(NULL);
90	rval = grscan(1, gid, NULL);
91	if (!_gr_stayopen)
92		endgrent();
93	return(rval ? &_gr_group : NULL);
94}
95
96static int
97start_gr()
98{
99	if (_gr_fp) {
100		rewind(_gr_fp);
101		return(1);
102	}
103	return((_gr_fp = fopen(_PATH_GROUP, "r")) ? 1 : 0);
104}
105
106void
107setgrent()
108{
109	(void) setgroupent(0);
110}
111
112int
113setgroupent(stayopen)
114	int stayopen;
115{
116	if (!start_gr())
117		return(0);
118	_gr_stayopen = stayopen;
119	return(1);
120}
121
122void
123endgrent()
124{
125	if (_gr_fp) {
126		(void)fclose(_gr_fp);
127		_gr_fp = NULL;
128	}
129}
130
131static int
132grscan(search, gid, name)
133	register int search, gid;
134	register char *name;
135{
136	register char *cp, **m;
137	char *bp;
138
139	for (;;) {
140		if (!fgets(line, sizeof(line), _gr_fp))
141			return(0);
142		bp = line;
143		/* skip lines that are too big */
144		if (!strchr(line, '\n')) {
145			int ch;
146
147			while ((ch = getc(_gr_fp)) != '\n' && ch != EOF)
148				;
149			continue;
150		}
151		_gr_group.gr_name = strsep(&bp, ":\n");
152		if (search && name && strcmp(_gr_group.gr_name, name))
153			continue;
154		_gr_group.gr_passwd = strsep(&bp, ":\n");
155		if (!(cp = strsep(&bp, ":\n")))
156			continue;
157		_gr_group.gr_gid = atoi(cp);
158		if (search && name == NULL && _gr_group.gr_gid != gid)
159			continue;
160		cp = NULL;
161		if (bp == NULL)
162			continue;
163		for (m = _gr_group.gr_mem = members;; bp++) {
164			if (m == &members[MAXGRP - 1])
165				break;
166			if (*bp == ',') {
167				if (cp) {
168					*bp = '\0';
169					*m++ = cp;
170					cp = NULL;
171				}
172			} else if (*bp == '\0' || *bp == '\n' || *bp == ' ') {
173				if (cp) {
174					*bp = '\0';
175					*m++ = cp;
176				}
177				break;
178			} else if (cp == NULL)
179				cp = bp;
180		}
181		*m = NULL;
182		return(1);
183	}
184	/* NOTREACHED */
185}
186