vars.c revision 216564 
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
32static char sccsid[] = "@(#)vars.c	8.1 (Berkeley) 6/6/93";
33#endif
34#endif /* not lint */
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD: head/usr.bin/mail/vars.c 216564 2010-12-19 16:25:23Z charnier $");
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 */
50void
51assign(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 */
74void
75vfree(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
86char *
87vcopy(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
106char *
107value(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
121struct var *
122lookup(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
136struct grouphead *
137findgroup(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 */
150void
151printgroup(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 */
170int
171hash(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