1/*	$OpenBSD: hack.rumors.c,v 1.10 2016/03/16 15:00:35 mestre Exp $	*/
2
3/*
4 * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
5 * Amsterdam
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are
10 * met:
11 *
12 * - Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 *
15 * - Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * - Neither the name of the Stichting Centrum voor Wiskunde en
20 * Informatica, nor the names of its contributors may be used to endorse or
21 * promote products derived from this software without specific prior
22 * written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
25 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
26 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
27 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
28 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
29 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
31 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
32 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
33 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 */
36
37/*
38 * Copyright (c) 1982 Jay Fenlason <hack@gnu.org>
39 * All rights reserved.
40 *
41 * Redistribution and use in source and binary forms, with or without
42 * modification, are permitted provided that the following conditions
43 * are met:
44 * 1. Redistributions of source code must retain the above copyright
45 *    notice, this list of conditions and the following disclaimer.
46 * 2. Redistributions in binary form must reproduce the above copyright
47 *    notice, this list of conditions and the following disclaimer in the
48 *    documentation and/or other materials provided with the distribution.
49 * 3. The name of the author may not be used to endorse or promote products
50 *    derived from this software without specific prior written permission.
51 *
52 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
53 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
54 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
55 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
56 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
57 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
58 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
59 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
60 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
61 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
62 */
63
64#include <err.h>
65#include <stdio.h>
66
67#include "hack.h"		/* for RUMORFILE and BSD (index) */
68
69#define	CHARSZ	8			/* number of bits in a char */
70int n_rumors = 0;
71int n_used_rumors = -1;
72char *usedbits;
73
74static void init_rumors(FILE *);
75static int  skipline(FILE *);
76static void outline(FILE *);
77static int  used(int);
78
79static void
80init_rumors(FILE *rumf)
81{
82	int i;
83
84	n_used_rumors = 0;
85	while(skipline(rumf)) n_rumors++;
86	if (fseek(rumf, 0L, SEEK_SET) == -1)
87		err(1, "fseek");
88	i = n_rumors/CHARSZ;
89	usedbits = (char *) alloc((unsigned)(i+1));
90	for( ; i>=0; i--) usedbits[i] = 0;
91}
92
93static int
94skipline(FILE *rumf)
95{
96	char line[COLNO];
97
98	while(1) {
99		if(!fgets(line, sizeof(line), rumf)) return(0);
100		if(strchr(line, '\n')) return(1);
101	}
102}
103
104static void
105outline(FILE *rumf)
106{
107	char line[COLNO];
108
109	if(!fgets(line, sizeof(line), rumf)) return;
110	line[strcspn(line, "\n")] = '\0';
111	pline("This cookie has a scrap of paper inside! It reads: ");
112	pline("%s", line);
113}
114
115void
116outrumor(void)
117{
118	int rn,i;
119	FILE *rumf;
120
121	if(n_rumors <= n_used_rumors ||
122	  (rumf = fopen(RUMORFILE, "r")) == (FILE *) 0) return;
123	if(n_used_rumors < 0) init_rumors(rumf);
124	if(!n_rumors) goto none;
125	rn = rn2(n_rumors - n_used_rumors);
126	i = 0;
127	while(rn || used(i)) {
128		(void) skipline(rumf);
129		if(!used(i)) rn--;
130		i++;
131	}
132	usedbits[i/CHARSZ] |= (1 << (i % CHARSZ));
133	n_used_rumors++;
134	outline(rumf);
135none:
136	(void) fclose(rumf);
137}
138
139static int
140used(int i)
141{
142	return(usedbits[i/CHARSZ] & (1 << (i % CHARSZ)));
143}
144