1 /*        $NetBSD: vars.c,v 1.19 2023/09/08 14:22:04 shm Exp $        */
2 
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 <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)vars.c      8.1 (Berkeley) 6/6/93";
36 #else
37 __RCSID("$NetBSD: vars.c,v 1.19 2023/09/08 14:22:04 shm Exp $");
38 #endif
39 #endif /* not lint */
40 
41 #include "rcv.h"
42 #include <util.h>
43 
44 #include "extern.h"
45 
46 /*
47  * Mail -- a mail program
48  *
49  * Variable handling stuff.
50  */
51 
52 /*
53  * Free up a variable string.  We do not bother to allocate
54  * strings whose value is "" since they are expected to be frequent.
55  * Thus, we cannot free same!
56  */
57 PUBLIC void
v_free(char * cp)58 v_free(char *cp)
59 {
60           if (*cp)
61                     free(cp);
62 }
63 
64 /*
65  * Copy a variable value into permanent (ie, not collected after each
66  * command) space.  Do not bother to alloc space for ""
67  */
68 PUBLIC char *
vcopy(const char str[])69 vcopy(const char str[])
70 {
71           char *new;
72           size_t len;
73 
74           if (*str == '\0')
75                     return estrdup("");
76           len = strlen(str) + 1;
77           new = emalloc(len);
78           (void)memmove(new, str, len);
79           return new;
80 }
81 
82 /*
83  * Hash the passed string and return an index into
84  * the variable or group hash table.
85  */
86 PUBLIC int
hash(const char * name)87 hash(const char *name)
88 {
89           unsigned int h = 0;
90 
91           while (*name) {
92                     h <<= 2;
93                     h += *name++;
94           }
95           return h % HSHSIZE;
96 }
97 
98 /*
99  * Locate a variable and return its variable
100  * node.
101  */
102 PUBLIC struct var *
lookup(const char name[])103 lookup(const char name[])
104 {
105           struct var *vp;
106 
107           for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
108                     if (*vp->v_name == *name && equal(vp->v_name, name))
109                               return vp;
110           return NULL;
111 }
112 
113 /*
114  * Assign a value to a variable.
115  */
116 PUBLIC void
assign(const char name[],const char values[])117 assign(const char name[], const char values[])
118 {
119           struct var *vp;
120           int h;
121 
122           h = hash(name);
123           vp = lookup(name);
124           if (vp == NULL) {
125                     vp = ecalloc(1, sizeof(*vp));
126                     vp->v_name = vcopy(name);
127                     vp->v_link = variables[h];
128                     variables[h] = vp;
129           }
130           else
131                 v_free(vp->v_value);
132           vp->v_value = vcopy(values);
133 }
134 
135 /*
136  * Get the value of a variable and return it.
137  * Look in the environment if its not available locally.
138  */
139 PUBLIC char *
value(const char name[])140 value(const char name[])
141 {
142           struct var *vp;
143 
144           if ((vp = lookup(name)) == NULL)
145                     return getenv(name);
146           return vp->v_value;
147 }
148 
149 /*
150  * Locate a group name and return it.
151  */
152 PUBLIC struct grouphead *
findgroup(const char name[])153 findgroup(const char name[])
154 {
155           struct grouphead *gh;
156 
157           for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
158                     if (*gh->g_name == *name && equal(gh->g_name, name))
159                               return gh;
160           return NULL;
161 }
162 
163 /*
164  * Print a group out on stdout
165  */
166 PUBLIC void
printgroup(const char name[])167 printgroup(const char name[])
168 {
169           struct grouphead *gh;
170           struct group *gp;
171 
172           if ((gh = findgroup(name)) == NULL) {
173                     (void)printf("\"%s\": not a group\n", name);
174                     return;
175           }
176           (void)printf("%s\t", gh->g_name);
177           for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
178                     (void)printf(" %s", gp->ge_name);
179           (void)putchar('\n');
180 }
181