xref: /freebsd/usr.bin/mail/vars.c (revision ea906c4152774dff300bb26fbfc1e4188351c89a)
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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 #if 0
36 static char sccsid[] = "@(#)vars.c	8.1 (Berkeley) 6/6/93";
37 #endif
38 #endif /* not lint */
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #include "rcv.h"
43 #include "extern.h"
44 
45 /*
46  * Mail -- a mail program
47  *
48  * Variable handling stuff.
49  */
50 
51 /*
52  * Assign a value to a variable.
53  */
54 void
55 assign(name, value)
56 	const char *name, *value;
57 {
58 	struct var *vp;
59 	int h;
60 
61 	h = hash(name);
62 	vp = lookup(name);
63 	if (vp == NULL) {
64 		vp = calloc(sizeof(*vp), 1);
65 		vp->v_name = vcopy(name);
66 		vp->v_link = variables[h];
67 		variables[h] = vp;
68 	}
69 	else
70 		vfree(vp->v_value);
71 	vp->v_value = vcopy(value);
72 }
73 
74 /*
75  * Free up a variable string.  We do not bother to allocate
76  * strings whose value is "" since they are expected to be frequent.
77  * Thus, we cannot free same!
78  */
79 void
80 vfree(cp)
81 	char *cp;
82 {
83 	if (*cp != '\0')
84 		(void)free(cp);
85 }
86 
87 /*
88  * Copy a variable value into permanent (ie, not collected after each
89  * command) space.  Do not bother to alloc space for ""
90  */
91 
92 char *
93 vcopy(str)
94 	const char *str;
95 {
96 	char *new;
97 	unsigned len;
98 
99 	if (*str == '\0')
100 		return ("");
101 	len = strlen(str) + 1;
102 	if ((new = malloc(len)) == NULL)
103 		err(1, "Out of memory");
104 	bcopy(str, new, (int)len);
105 	return (new);
106 }
107 
108 /*
109  * Get the value of a variable and return it.
110  * Look in the environment if its not available locally.
111  */
112 
113 char *
114 value(name)
115 	const char *name;
116 {
117 	struct var *vp;
118 
119 	if ((vp = lookup(name)) == NULL)
120 		return (getenv(name));
121 	return (vp->v_value);
122 }
123 
124 /*
125  * Locate a variable and return its variable
126  * node.
127  */
128 
129 struct var *
130 lookup(name)
131 	const char *name;
132 {
133 	struct var *vp;
134 
135 	for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
136 		if (*vp->v_name == *name && equal(vp->v_name, name))
137 			return (vp);
138 	return (NULL);
139 }
140 
141 /*
142  * Locate a group name and return it.
143  */
144 
145 struct grouphead *
146 findgroup(name)
147 	char name[];
148 {
149 	struct grouphead *gh;
150 
151 	for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
152 		if (*gh->g_name == *name && equal(gh->g_name, name))
153 			return (gh);
154 	return (NULL);
155 }
156 
157 /*
158  * Print a group out on stdout
159  */
160 void
161 printgroup(name)
162 	char name[];
163 {
164 	struct grouphead *gh;
165 	struct group *gp;
166 
167 	if ((gh = findgroup(name)) == NULL) {
168 		printf("\"%s\": not a group\n", name);
169 		return;
170 	}
171 	printf("%s\t", gh->g_name);
172 	for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
173 		printf(" %s", gp->ge_name);
174 	printf("\n");
175 }
176 
177 /*
178  * Hash the passed string and return an index into
179  * the variable or group hash table.
180  */
181 int
182 hash(name)
183 	const char *name;
184 {
185 	int h = 0;
186 
187 	while (*name != '\0') {
188 		h <<= 2;
189 		h += *name++;
190 	}
191 	if (h < 0 && (h = -h) < 0)
192 		h = 0;
193 	return (h % HSHSIZE);
194 }
195