xref: /freebsd/usr.bin/mail/vars.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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 #if 0
34 static char sccsid[] = "@(#)vars.c	8.1 (Berkeley) 6/6/93";
35 #endif
36 #endif /* not lint */
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include "rcv.h"
41 #include "extern.h"
42 
43 /*
44  * Mail -- a mail program
45  *
46  * Variable handling stuff.
47  */
48 
49 /*
50  * Assign a value to a variable.
51  */
52 void
53 assign(const char *name, const char *value)
54 {
55 	struct var *vp;
56 	int h;
57 
58 	h = hash(name);
59 	vp = lookup(name);
60 	if (vp == NULL) {
61 		if ((vp = calloc(1, sizeof(*vp))) == NULL)
62 			err(1, "Out of memory");
63 		vp->v_name = vcopy(name);
64 		vp->v_link = variables[h];
65 		variables[h] = vp;
66 	}
67 	else
68 		vfree(vp->v_value);
69 	vp->v_value = vcopy(value);
70 }
71 
72 /*
73  * Free up a variable string.  We do not bother to allocate
74  * strings whose value is "" since they are expected to be frequent.
75  * Thus, we cannot free same!
76  */
77 void
78 vfree(char *cp)
79 {
80 	if (*cp != '\0')
81 		(void)free(cp);
82 }
83 
84 /*
85  * Copy a variable value into permanent (ie, not collected after each
86  * command) space.  Do not bother to alloc space for ""
87  */
88 
89 char *
90 vcopy(const char *str)
91 {
92 	char *new;
93 	unsigned len;
94 
95 	if (*str == '\0')
96 		return ("");
97 	len = strlen(str) + 1;
98 	if ((new = malloc(len)) == NULL)
99 		err(1, "Out of memory");
100 	bcopy(str, new, (int)len);
101 	return (new);
102 }
103 
104 /*
105  * Get the value of a variable and return it.
106  * Look in the environment if its not available locally.
107  */
108 
109 char *
110 value(const char *name)
111 {
112 	struct var *vp;
113 
114 	if ((vp = lookup(name)) == NULL)
115 		return (getenv(name));
116 	return (vp->v_value);
117 }
118 
119 /*
120  * Locate a variable and return its variable
121  * node.
122  */
123 
124 struct var *
125 lookup(const char *name)
126 {
127 	struct var *vp;
128 
129 	for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
130 		if (*vp->v_name == *name && equal(vp->v_name, name))
131 			return (vp);
132 	return (NULL);
133 }
134 
135 /*
136  * Locate a group name and return it.
137  */
138 
139 struct grouphead *
140 findgroup(char name[])
141 {
142 	struct grouphead *gh;
143 
144 	for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
145 		if (*gh->g_name == *name && equal(gh->g_name, name))
146 			return (gh);
147 	return (NULL);
148 }
149 
150 /*
151  * Print a group out on stdout
152  */
153 void
154 printgroup(char name[])
155 {
156 	struct grouphead *gh;
157 	struct group *gp;
158 
159 	if ((gh = findgroup(name)) == NULL) {
160 		printf("\"%s\": not a group\n", name);
161 		return;
162 	}
163 	printf("%s\t", gh->g_name);
164 	for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
165 		printf(" %s", gp->ge_name);
166 	printf("\n");
167 }
168 
169 /*
170  * Hash the passed string and return an index into
171  * the variable or group hash table.
172  */
173 int
174 hash(const char *name)
175 {
176 	int h = 0;
177 
178 	while (*name != '\0') {
179 		h <<= 2;
180 		h += *name++;
181 	}
182 	if (h < 0 && (h = -h) < 0)
183 		h = 0;
184 	return (h % HSHSIZE);
185 }
186