xref: /freebsd/usr.bin/mail/vars.c (revision da52b4caaf187775f6b56a72c6b16e94ad728f7b)
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
32 static char sccsid[] = "@(#)vars.c	8.1 (Berkeley) 6/6/93";
33 #endif
34 #endif /* not lint */
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
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  */
50 void
51 assign(name, value)
52 	const char *name, *value;
53 {
54 	struct var *vp;
55 	int h;
56 
57 	h = hash(name);
58 	vp = lookup(name);
59 	if (vp == NULL) {
60 		vp = calloc(sizeof(*vp), 1);
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  */
75 void
76 vfree(cp)
77 	char *cp;
78 {
79 	if (*cp != '\0')
80 		(void)free(cp);
81 }
82 
83 /*
84  * Copy a variable value into permanent (ie, not collected after each
85  * command) space.  Do not bother to alloc space for ""
86  */
87 
88 char *
89 vcopy(str)
90 	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(name)
111 	const char *name;
112 {
113 	struct var *vp;
114 
115 	if ((vp = lookup(name)) == NULL)
116 		return (getenv(name));
117 	return (vp->v_value);
118 }
119 
120 /*
121  * Locate a variable and return its variable
122  * node.
123  */
124 
125 struct var *
126 lookup(name)
127 	const char *name;
128 {
129 	struct var *vp;
130 
131 	for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
132 		if (*vp->v_name == *name && equal(vp->v_name, name))
133 			return (vp);
134 	return (NULL);
135 }
136 
137 /*
138  * Locate a group name and return it.
139  */
140 
141 struct grouphead *
142 findgroup(name)
143 	char name[];
144 {
145 	struct grouphead *gh;
146 
147 	for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
148 		if (*gh->g_name == *name && equal(gh->g_name, name))
149 			return (gh);
150 	return (NULL);
151 }
152 
153 /*
154  * Print a group out on stdout
155  */
156 void
157 printgroup(name)
158 	char name[];
159 {
160 	struct grouphead *gh;
161 	struct group *gp;
162 
163 	if ((gh = findgroup(name)) == NULL) {
164 		printf("\"%s\": not a group\n", name);
165 		return;
166 	}
167 	printf("%s\t", gh->g_name);
168 	for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
169 		printf(" %s", gp->ge_name);
170 	printf("\n");
171 }
172 
173 /*
174  * Hash the passed string and return an index into
175  * the variable or group hash table.
176  */
177 int
178 hash(name)
179 	const char *name;
180 {
181 	int h = 0;
182 
183 	while (*name != '\0') {
184 		h <<= 2;
185 		h += *name++;
186 	}
187 	if (h < 0 && (h = -h) < 0)
188 		h = 0;
189 	return (h % HSHSIZE);
190 }
191