xref: /freebsd/usr.bin/mail/vars.c (revision 397e83df75e0fcd0d3fcb95ae4d794cb7600fc89)
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  */
44 void
45 assign(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  */
69 void
70 vfree(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 
81 char *
82 vcopy(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 
101 char *
102 value(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 
116 struct var *
117 lookup(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 
131 struct grouphead *
132 findgroup(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  */
145 void
146 printgroup(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  */
165 int
166 hash(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