xref: /freebsd/usr.bin/mail/vars.c (revision 3f0164abf32b9b761e0a2cb4bdca3a8b84f156d4)
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(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 		vp = calloc(sizeof(*vp), 1);
60 		vp->v_name = vcopy(name);
61 		vp->v_link = variables[h];
62 		variables[h] = vp;
63 	}
64 	else
65 		vfree(vp->v_value);
66 	vp->v_value = vcopy(value);
67 }
68 
69 /*
70  * Free up a variable string.  We do not bother to allocate
71  * strings whose value is "" since they are expected to be frequent.
72  * Thus, we cannot free same!
73  */
74 void
75 vfree(char *cp)
76 {
77 	if (*cp != '\0')
78 		(void)free(cp);
79 }
80 
81 /*
82  * Copy a variable value into permanent (ie, not collected after each
83  * command) space.  Do not bother to alloc space for ""
84  */
85 
86 char *
87 vcopy(const char *str)
88 {
89 	char *new;
90 	unsigned len;
91 
92 	if (*str == '\0')
93 		return ("");
94 	len = strlen(str) + 1;
95 	if ((new = malloc(len)) == NULL)
96 		err(1, "Out of memory");
97 	bcopy(str, new, (int)len);
98 	return (new);
99 }
100 
101 /*
102  * Get the value of a variable and return it.
103  * Look in the environment if its not available locally.
104  */
105 
106 char *
107 value(const char *name)
108 {
109 	struct var *vp;
110 
111 	if ((vp = lookup(name)) == NULL)
112 		return (getenv(name));
113 	return (vp->v_value);
114 }
115 
116 /*
117  * Locate a variable and return its variable
118  * node.
119  */
120 
121 struct var *
122 lookup(const char *name)
123 {
124 	struct var *vp;
125 
126 	for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
127 		if (*vp->v_name == *name && equal(vp->v_name, name))
128 			return (vp);
129 	return (NULL);
130 }
131 
132 /*
133  * Locate a group name and return it.
134  */
135 
136 struct grouphead *
137 findgroup(char name[])
138 {
139 	struct grouphead *gh;
140 
141 	for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
142 		if (*gh->g_name == *name && equal(gh->g_name, name))
143 			return (gh);
144 	return (NULL);
145 }
146 
147 /*
148  * Print a group out on stdout
149  */
150 void
151 printgroup(char name[])
152 {
153 	struct grouphead *gh;
154 	struct group *gp;
155 
156 	if ((gh = findgroup(name)) == NULL) {
157 		printf("\"%s\": not a group\n", name);
158 		return;
159 	}
160 	printf("%s\t", gh->g_name);
161 	for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
162 		printf(" %s", gp->ge_name);
163 	printf("\n");
164 }
165 
166 /*
167  * Hash the passed string and return an index into
168  * the variable or group hash table.
169  */
170 int
171 hash(const char *name)
172 {
173 	int h = 0;
174 
175 	while (*name != '\0') {
176 		h <<= 2;
177 		h += *name++;
178 	}
179 	if (h < 0 && (h = -h) < 0)
180 		h = 0;
181 	return (h % HSHSIZE);
182 }
183