1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 "rcv.h"
33#include "extern.h"
34
35/*
36 * Mail -- a mail program
37 *
38 * Variable handling stuff.
39 */
40
41/*
42 * Assign a value to a variable.
43 */
44void
45assign(const char *name, const char *value)
46{
47	struct var *vp;
48	int h;
49
50	h = hash(name);
51	vp = lookup(name);
52	if (vp == NULL) {
53		if ((vp = calloc(1, sizeof(*vp))) == NULL)
54			err(1, "Out of memory");
55		vp->v_name = vcopy(name);
56		vp->v_link = variables[h];
57		variables[h] = vp;
58	}
59	else
60		vfree(vp->v_value);
61	vp->v_value = vcopy(value);
62}
63
64/*
65 * Free up a variable string.  We do not bother to allocate
66 * strings whose value is "" since they are expected to be frequent.
67 * Thus, we cannot free same!
68 */
69void
70vfree(char *cp)
71{
72	if (*cp != '\0')
73		(void)free(cp);
74}
75
76/*
77 * Copy a variable value into permanent (ie, not collected after each
78 * command) space.  Do not bother to alloc space for ""
79 */
80
81char *
82vcopy(const char *str)
83{
84	char *new;
85	unsigned len;
86
87	if (*str == '\0')
88		return ("");
89	len = strlen(str) + 1;
90	if ((new = malloc(len)) == NULL)
91		err(1, "Out of memory");
92	bcopy(str, new, (int)len);
93	return (new);
94}
95
96/*
97 * Get the value of a variable and return it.
98 * Look in the environment if its not available locally.
99 */
100
101char *
102value(const char *name)
103{
104	struct var *vp;
105
106	if ((vp = lookup(name)) == NULL)
107		return (getenv(name));
108	return (vp->v_value);
109}
110
111/*
112 * Locate a variable and return its variable
113 * node.
114 */
115
116struct var *
117lookup(const char *name)
118{
119	struct var *vp;
120
121	for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
122		if (*vp->v_name == *name && equal(vp->v_name, name))
123			return (vp);
124	return (NULL);
125}
126
127/*
128 * Locate a group name and return it.
129 */
130
131struct grouphead *
132findgroup(char name[])
133{
134	struct grouphead *gh;
135
136	for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
137		if (*gh->g_name == *name && equal(gh->g_name, name))
138			return (gh);
139	return (NULL);
140}
141
142/*
143 * Print a group out on stdout
144 */
145void
146printgroup(char name[])
147{
148	struct grouphead *gh;
149	struct group *gp;
150
151	if ((gh = findgroup(name)) == NULL) {
152		printf("\"%s\": not a group\n", name);
153		return;
154	}
155	printf("%s\t", gh->g_name);
156	for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
157		printf(" %s", gp->ge_name);
158	printf("\n");
159}
160
161/*
162 * Hash the passed string and return an index into
163 * the variable or group hash table.
164 */
165int
166hash(const char *name)
167{
168	int h = 0;
169
170	while (*name != '\0') {
171		h <<= 2;
172		h += *name++;
173	}
174	if (h < 0 && (h = -h) < 0)
175		h = 0;
176	return (h % HSHSIZE);
177}
178