vars.c revision 331722 
1/*
2 * Copyright (c) 1980, 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 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#ifndef lint
31#if 0
32static char sccsid[] = "@(#)vars.c	8.1 (Berkeley) 6/6/93";
33#endif
34#endif /* not lint */
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD: stable/11/usr.bin/mail/vars.c 331722 2018-03-29 02:50:57Z eadler $");
37
38#include "rcv.h"
39#include "extern.h"
40
41/*
42 * Mail -- a mail program
43 *
44 * Variable handling stuff.
45 */
46
47/*
48 * Assign a value to a variable.
49 */
50void
51assign(const char *name, const char *value)
52{
53	struct var *vp;
54	int h;
55
56	h = hash(name);
57	vp = lookup(name);
58	if (vp == NULL) {
59		if ((vp = calloc(1, sizeof(*vp))) == NULL)
60			err(1, "Out of memory");
61		vp->v_name = vcopy(name);
62		vp->v_link = variables[h];
63		variables[h] = vp;
64	}
65	else
66		vfree(vp->v_value);
67	vp->v_value = vcopy(value);
68}
69
70/*
71 * Free up a variable string.  We do not bother to allocate
72 * strings whose value is "" since they are expected to be frequent.
73 * Thus, we cannot free same!
74 */
75void
76vfree(char *cp)
77{
78	if (*cp != '\0')
79		(void)free(cp);
80}
81
82/*
83 * Copy a variable value into permanent (ie, not collected after each
84 * command) space.  Do not bother to alloc space for ""
85 */
86
87char *
88vcopy(const char *str)
89{
90	char *new;
91	unsigned len;
92
93	if (*str == '\0')
94		return ("");
95	len = strlen(str) + 1;
96	if ((new = malloc(len)) == NULL)
97		err(1, "Out of memory");
98	bcopy(str, new, (int)len);
99	return (new);
100}
101
102/*
103 * Get the value of a variable and return it.
104 * Look in the environment if its not available locally.
105 */
106
107char *
108value(const char *name)
109{
110	struct var *vp;
111
112	if ((vp = lookup(name)) == NULL)
113		return (getenv(name));
114	return (vp->v_value);
115}
116
117/*
118 * Locate a variable and return its variable
119 * node.
120 */
121
122struct var *
123lookup(const char *name)
124{
125	struct var *vp;
126
127	for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
128		if (*vp->v_name == *name && equal(vp->v_name, name))
129			return (vp);
130	return (NULL);
131}
132
133/*
134 * Locate a group name and return it.
135 */
136
137struct grouphead *
138findgroup(char name[])
139{
140	struct grouphead *gh;
141
142	for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
143		if (*gh->g_name == *name && equal(gh->g_name, name))
144			return (gh);
145	return (NULL);
146}
147
148/*
149 * Print a group out on stdout
150 */
151void
152printgroup(char name[])
153{
154	struct grouphead *gh;
155	struct group *gp;
156
157	if ((gh = findgroup(name)) == NULL) {
158		printf("\"%s\": not a group\n", name);
159		return;
160	}
161	printf("%s\t", gh->g_name);
162	for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
163		printf(" %s", gp->ge_name);
164	printf("\n");
165}
166
167/*
168 * Hash the passed string and return an index into
169 * the variable or group hash table.
170 */
171int
172hash(const char *name)
173{
174	int h = 0;
175
176	while (*name != '\0') {
177		h <<= 2;
178		h += *name++;
179	}
180	if (h < 0 && (h = -h) < 0)
181		h = 0;
182	return (h % HSHSIZE);
183}
184