xref: /freebsd/usr.bin/mail/vars.c (revision 41059135ce931c0f1014a999ffabc6bc470ce856)
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 
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(const char *name, const char *value)
52 {
53 	struct var *vp;
54 	int h;
55 
56 	h = hash(name);
57 	vp = lookup(name);
58 	if (vp == NULL) {
59 		if ((vp = calloc(1, sizeof(*vp))) == NULL)
60 			err(1, "Out of memory");
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(char *cp)
77 {
78 	if (*cp != '\0')
79 		(void)free(cp);
80 }
81 
82 /*
83  * Copy a variable value into permanent (ie, not collected after each
84  * command) space.  Do not bother to alloc space for ""
85  */
86 
87 char *
88 vcopy(const char *str)
89 {
90 	char *new;
91 	unsigned len;
92 
93 	if (*str == '\0')
94 		return ("");
95 	len = strlen(str) + 1;
96 	if ((new = malloc(len)) == NULL)
97 		err(1, "Out of memory");
98 	bcopy(str, new, (int)len);
99 	return (new);
100 }
101 
102 /*
103  * Get the value of a variable and return it.
104  * Look in the environment if its not available locally.
105  */
106 
107 char *
108 value(const char *name)
109 {
110 	struct var *vp;
111 
112 	if ((vp = lookup(name)) == NULL)
113 		return (getenv(name));
114 	return (vp->v_value);
115 }
116 
117 /*
118  * Locate a variable and return its variable
119  * node.
120  */
121 
122 struct var *
123 lookup(const char *name)
124 {
125 	struct var *vp;
126 
127 	for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
128 		if (*vp->v_name == *name && equal(vp->v_name, name))
129 			return (vp);
130 	return (NULL);
131 }
132 
133 /*
134  * Locate a group name and return it.
135  */
136 
137 struct grouphead *
138 findgroup(char name[])
139 {
140 	struct grouphead *gh;
141 
142 	for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
143 		if (*gh->g_name == *name && equal(gh->g_name, name))
144 			return (gh);
145 	return (NULL);
146 }
147 
148 /*
149  * Print a group out on stdout
150  */
151 void
152 printgroup(char name[])
153 {
154 	struct grouphead *gh;
155 	struct group *gp;
156 
157 	if ((gh = findgroup(name)) == NULL) {
158 		printf("\"%s\": not a group\n", name);
159 		return;
160 	}
161 	printf("%s\t", gh->g_name);
162 	for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
163 		printf(" %s", gp->ge_name);
164 	printf("\n");
165 }
166 
167 /*
168  * Hash the passed string and return an index into
169  * the variable or group hash table.
170  */
171 int
172 hash(const char *name)
173 {
174 	int h = 0;
175 
176 	while (*name != '\0') {
177 		h <<= 2;
178 		h += *name++;
179 	}
180 	if (h < 0 && (h = -h) < 0)
181 		h = 0;
182 	return (h % HSHSIZE);
183 }
184