1/*	$NetBSD: vars.c,v 1.17 2006/11/28 18:45:32 christos Exp $	*/
2
3/*
4 * Copyright (c) 1980, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#ifndef lint
34#if 0
35static char sccsid[] = "@(#)vars.c	8.1 (Berkeley) 6/6/93";
36#else
37__RCSID("$NetBSD: vars.c,v 1.17 2006/11/28 18:45:32 christos Exp $");
38#endif
39#endif /* not lint */
40
41#include "rcv.h"
42#include <util.h>
43
44#include "extern.h"
45
46/*
47 * Mail -- a mail program
48 *
49 * Variable handling stuff.
50 */
51
52/*
53 * Free up a variable string.  We do not bother to allocate
54 * strings whose value is "" since they are expected to be frequent.
55 * Thus, we cannot free same!
56 */
57PUBLIC void
58v_free(char *cp)
59{
60	if (*cp)
61		free(cp);
62}
63
64/*
65 * Copy a variable value into permanent (ie, not collected after each
66 * command) space.  Do not bother to alloc space for ""
67 */
68PUBLIC char *
69vcopy(const char str[])
70{
71	char *new;
72	size_t len;
73
74	if (*str == '\0')
75		return estrdup("");
76	len = strlen(str) + 1;
77	new = emalloc(len);
78	(void)memmove(new, str, len);
79	return new;
80}
81
82/*
83 * Hash the passed string and return an index into
84 * the variable or group hash table.
85 */
86PUBLIC int
87hash(const char *name)
88{
89	int h = 0;
90
91	while (*name) {
92		h <<= 2;
93		h += *name++;
94	}
95	if (h < 0 && (h = -h) < 0)
96		h = 0;
97	return h % HSHSIZE;
98}
99
100/*
101 * Locate a variable and return its variable
102 * node.
103 */
104PUBLIC struct var *
105lookup(const char name[])
106{
107	struct var *vp;
108
109	for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
110		if (*vp->v_name == *name && equal(vp->v_name, name))
111			return vp;
112	return NULL;
113}
114
115/*
116 * Assign a value to a variable.
117 */
118PUBLIC void
119assign(const char name[], const char values[])
120{
121	struct var *vp;
122	int h;
123
124	h = hash(name);
125	vp = lookup(name);
126	if (vp == NULL) {
127		vp = ecalloc(1, sizeof(*vp));
128		vp->v_name = vcopy(name);
129		vp->v_link = variables[h];
130		variables[h] = vp;
131	}
132	else
133                v_free(vp->v_value);
134	vp->v_value = vcopy(values);
135}
136
137/*
138 * Get the value of a variable and return it.
139 * Look in the environment if its not available locally.
140 */
141PUBLIC char *
142value(const char name[])
143{
144	struct var *vp;
145
146	if ((vp = lookup(name)) == NULL)
147		return getenv(name);
148	return vp->v_value;
149}
150
151/*
152 * Locate a group name and return it.
153 */
154PUBLIC struct grouphead *
155findgroup(const char name[])
156{
157	struct grouphead *gh;
158
159	for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
160		if (*gh->g_name == *name && equal(gh->g_name, name))
161			return gh;
162	return NULL;
163}
164
165/*
166 * Print a group out on stdout
167 */
168PUBLIC void
169printgroup(const char name[])
170{
171	struct grouphead *gh;
172	struct group *gp;
173
174	if ((gh = findgroup(name)) == NULL) {
175		(void)printf("\"%s\": not a group\n", name);
176		return;
177	}
178	(void)printf("%s\t", gh->g_name);
179	for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
180		(void)printf(" %s", gp->ge_name);
181	(void)putchar('\n');
182}
183