xref: /dragonfly/usr.bin/mail/vars.c (revision cf89a63b)
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. 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  * @(#)vars.c	8.1 (Berkeley) 6/6/93
30  * $FreeBSD: src/usr.bin/mail/vars.c,v 1.1.1.1.14.3 2003/01/06 05:46:04 mikeh Exp $
31  * $DragonFly: src/usr.bin/mail/vars.c,v 1.4 2004/09/08 03:01:11 joerg Exp $
32  */
33 
34 #include "rcv.h"
35 #include "extern.h"
36 
37 /*
38  * Mail -- a mail program
39  *
40  * Variable handling stuff.
41  */
42 
43 /*
44  * Assign a value to a variable.
45  */
46 void
47 assign(const char *name, const char *value)
48 {
49 	struct var *vp;
50 	int h;
51 
52 	h = hash(name);
53 	vp = lookup(name);
54 	if (vp == NULL) {
55 		vp = calloc(sizeof(*vp), 1);
56 		vp->v_name = vcopy(name);
57 		vp->v_link = variables[h];
58 		variables[h] = vp;
59 	}
60 	else
61 		vfree(vp->v_value);
62 	vp->v_value = vcopy(value);
63 }
64 
65 /*
66  * Free up a variable string.  We do not bother to allocate
67  * strings whose value is "" since they are expected to be frequent.
68  * Thus, we cannot free same!
69  */
70 void
71 vfree(char *cp)
72 {
73 	if (*cp != '\0')
74 		free(cp);
75 }
76 
77 /*
78  * Copy a variable value into permanent (ie, not collected after each
79  * command) space.  Do not bother to alloc space for ""
80  */
81 
82 char *
83 vcopy(const char *str)
84 {
85 	char *new;
86 	unsigned len;
87 
88 	if (*str == '\0')
89 		return ("");
90 	len = strlen(str) + 1;
91 	if ((new = malloc(len)) == NULL)
92 		err(1, "Out of memory");
93 	bcopy(str, new, (int)len);
94 	return (new);
95 }
96 
97 /*
98  * Get the value of a variable and return it.
99  * Look in the environment if its not available locally.
100  */
101 
102 char *
103 value(const char *name)
104 {
105 	struct var *vp;
106 
107 	if ((vp = lookup(name)) == NULL)
108 		return (getenv(name));
109 	return (vp->v_value);
110 }
111 
112 /*
113  * Locate a variable and return its variable
114  * node.
115  */
116 
117 struct var *
118 lookup(const char *name)
119 {
120 	struct var *vp;
121 
122 	for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
123 		if (*vp->v_name == *name && equal(vp->v_name, name))
124 			return (vp);
125 	return (NULL);
126 }
127 
128 /*
129  * Locate a group name and return it.
130  */
131 
132 struct grouphead *
133 findgroup(char *name)
134 {
135 	struct grouphead *gh;
136 
137 	for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
138 		if (*gh->g_name == *name && equal(gh->g_name, name))
139 			return (gh);
140 	return (NULL);
141 }
142 
143 /*
144  * Print a group out on stdout
145  */
146 void
147 printgroup(char *name)
148 {
149 	struct grouphead *gh;
150 	struct group *gp;
151 
152 	if ((gh = findgroup(name)) == NULL) {
153 		printf("\"%s\": not a group\n", name);
154 		return;
155 	}
156 	printf("%s\t", gh->g_name);
157 	for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
158 		printf(" %s", gp->ge_name);
159 	printf("\n");
160 }
161 
162 /*
163  * Hash the passed string and return an index into
164  * the variable or group hash table.
165  */
166 int
167 hash(const char *name)
168 {
169 	int h = 0;
170 
171 	while (*name != '\0') {
172 		h <<= 2;
173 		h += *name++;
174 	}
175 	if (h < 0 && (h = -h) < 0)
176 		h = 0;
177 	return (h % HSHSIZE);
178 }
179