xref: /freebsd/usr.bin/mail/vars.c (revision bdcbfde31e8e9b343f113a1956384bdf30d1ed62)
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 #ifndef lint
33 #endif /* not lint */
34 #include <sys/cdefs.h>
35 #include "rcv.h"
36 #include "extern.h"
37 
38 /*
39  * Mail -- a mail program
40  *
41  * Variable handling stuff.
42  */
43 
44 /*
45  * Assign a value to a variable.
46  */
47 void
48 assign(const char *name, const char *value)
49 {
50 	struct var *vp;
51 	int h;
52 
53 	h = hash(name);
54 	vp = lookup(name);
55 	if (vp == NULL) {
56 		if ((vp = calloc(1, sizeof(*vp))) == NULL)
57 			err(1, "Out of memory");
58 		vp->v_name = vcopy(name);
59 		vp->v_link = variables[h];
60 		variables[h] = vp;
61 	}
62 	else
63 		vfree(vp->v_value);
64 	vp->v_value = vcopy(value);
65 }
66 
67 /*
68  * Free up a variable string.  We do not bother to allocate
69  * strings whose value is "" since they are expected to be frequent.
70  * Thus, we cannot free same!
71  */
72 void
73 vfree(char *cp)
74 {
75 	if (*cp != '\0')
76 		(void)free(cp);
77 }
78 
79 /*
80  * Copy a variable value into permanent (ie, not collected after each
81  * command) space.  Do not bother to alloc space for ""
82  */
83 
84 char *
85 vcopy(const char *str)
86 {
87 	char *new;
88 	unsigned len;
89 
90 	if (*str == '\0')
91 		return ("");
92 	len = strlen(str) + 1;
93 	if ((new = malloc(len)) == NULL)
94 		err(1, "Out of memory");
95 	bcopy(str, new, (int)len);
96 	return (new);
97 }
98 
99 /*
100  * Get the value of a variable and return it.
101  * Look in the environment if its not available locally.
102  */
103 
104 char *
105 value(const char *name)
106 {
107 	struct var *vp;
108 
109 	if ((vp = lookup(name)) == NULL)
110 		return (getenv(name));
111 	return (vp->v_value);
112 }
113 
114 /*
115  * Locate a variable and return its variable
116  * node.
117  */
118 
119 struct var *
120 lookup(const char *name)
121 {
122 	struct var *vp;
123 
124 	for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
125 		if (*vp->v_name == *name && equal(vp->v_name, name))
126 			return (vp);
127 	return (NULL);
128 }
129 
130 /*
131  * Locate a group name and return it.
132  */
133 
134 struct grouphead *
135 findgroup(char name[])
136 {
137 	struct grouphead *gh;
138 
139 	for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
140 		if (*gh->g_name == *name && equal(gh->g_name, name))
141 			return (gh);
142 	return (NULL);
143 }
144 
145 /*
146  * Print a group out on stdout
147  */
148 void
149 printgroup(char name[])
150 {
151 	struct grouphead *gh;
152 	struct group *gp;
153 
154 	if ((gh = findgroup(name)) == NULL) {
155 		printf("\"%s\": not a group\n", name);
156 		return;
157 	}
158 	printf("%s\t", gh->g_name);
159 	for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
160 		printf(" %s", gp->ge_name);
161 	printf("\n");
162 }
163 
164 /*
165  * Hash the passed string and return an index into
166  * the variable or group hash table.
167  */
168 int
169 hash(const char *name)
170 {
171 	int h = 0;
172 
173 	while (*name != '\0') {
174 		h <<= 2;
175 		h += *name++;
176 	}
177 	if (h < 0 && (h = -h) < 0)
178 		h = 0;
179 	return (h % HSHSIZE);
180 }
181