vars.c revision 74769 
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
36static char sccsid[] = "@(#)vars.c	8.1 (Berkeley) 6/6/93";
37#endif
38static const char rcsid[] =
39  "$FreeBSD: head/usr.bin/mail/vars.c 74769 2001-03-25 04:57:05Z mikeh $";
40#endif /* not lint */
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 */
54void
55assign(name, value)
56	char name[], value[];
57{
58	register struct var *vp;
59	register int h;
60
61	h = hash(name);
62	vp = lookup(name);
63	if (vp == NOVAR) {
64		vp = (struct var *) 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 */
79void
80vfree(cp)
81	char *cp;
82{
83	if (*cp)
84		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
92char *
93vcopy(str)
94	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
113char *
114value(name)
115	char name[];
116{
117	register struct var *vp;
118
119	if ((vp = lookup(name)) == NOVAR)
120		return(getenv(name));
121	return(vp->v_value);
122}
123
124/*
125 * Locate a variable and return its variable
126 * node.
127 */
128
129struct var *
130lookup(name)
131	register char name[];
132{
133	register struct var *vp;
134
135	for (vp = variables[hash(name)]; vp != NOVAR; vp = vp->v_link)
136		if (*vp->v_name == *name && equal(vp->v_name, name))
137			return(vp);
138	return(NOVAR);
139}
140
141/*
142 * Locate a group name and return it.
143 */
144
145struct grouphead *
146findgroup(name)
147	register char name[];
148{
149	register struct grouphead *gh;
150
151	for (gh = groups[hash(name)]; gh != NOGRP; gh = gh->g_link)
152		if (*gh->g_name == *name && equal(gh->g_name, name))
153			return(gh);
154	return(NOGRP);
155}
156
157/*
158 * Print a group out on stdout
159 */
160void
161printgroup(name)
162	char name[];
163{
164	register struct grouphead *gh;
165	register struct group *gp;
166
167	if ((gh = findgroup(name)) == NOGRP) {
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 != NOGE; gp = gp->ge_link)
173		printf(" %s", gp->ge_name);
174	putchar('\n');
175}
176
177/*
178 * Hash the passed string and return an index into
179 * the variable or group hash table.
180 */
181int
182hash(name)
183	register char *name;
184{
185	register h = 0;
186
187	while (*name) {
188		h <<= 2;
189		h += *name++;
190	}
191	if (h < 0 && (h = -h) < 0)
192		h = 0;
193	return (h % HSHSIZE);
194}
195