Return to hack.rumors.c CVS log

Up to [local] / src / games / hack

Prefer fseek(3) over rewind(3) since the latter although it also calls fseek
then additionally it calls clearerr(3) deliberately but we want to catch any
error that may happen and this way we couldn't catch it

OK tb@

/*	$OpenBSD: hack.rumors.c,v 1.10 2016/03/16 15:00:35 mestre Exp $	*/

/*
 * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
 * Amsterdam
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the Stichting Centrum voor Wiskunde en
 * Informatica, nor the names of its contributors may be used to endorse or
 * promote products derived from this software without specific prior
 * written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Copyright (c) 1982 Jay Fenlason <hack@gnu.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <err.h>
#include <stdio.h>

#include "hack.h"		/* for RUMORFILE and BSD (index) */

#define	CHARSZ	8			/* number of bits in a char */
int n_rumors = 0;
int n_used_rumors = -1;
char *usedbits;

static void init_rumors(FILE *);
static int  skipline(FILE *);
static void outline(FILE *);
static int  used(int);

static void
init_rumors(FILE *rumf)
{
	int i;

	n_used_rumors = 0;
	while(skipline(rumf)) n_rumors++;
	if (fseek(rumf, 0L, SEEK_SET) == -1)
		err(1, "fseek");
	i = n_rumors/CHARSZ;
	usedbits = (char *) alloc((unsigned)(i+1));
	for( ; i>=0; i--) usedbits[i] = 0;
}

static int
skipline(FILE *rumf)
{
	char line[COLNO];

	while(1) {
		if(!fgets(line, sizeof(line), rumf)) return(0);
		if(strchr(line, '\n')) return(1);
	}
}

static void
outline(FILE *rumf)
{
	char line[COLNO];

	if(!fgets(line, sizeof(line), rumf)) return;
	line[strcspn(line, "\n")] = '\0';
	pline("This cookie has a scrap of paper inside! It reads: ");
	pline("%s", line);
}

void
outrumor(void)
{
	int rn,i;
	FILE *rumf;

	if(n_rumors <= n_used_rumors ||
	  (rumf = fopen(RUMORFILE, "r")) == (FILE *) 0) return;
	if(n_used_rumors < 0) init_rumors(rumf);
	if(!n_rumors) goto none;
	rn = rn2(n_rumors - n_used_rumors);
	i = 0;
	while(rn || used(i)) {
		(void) skipline(rumf);
		if(!used(i)) rn--;
		i++;
	}
	usedbits[i/CHARSZ] |= (1 << (i % CHARSZ));
	n_used_rumors++;
	outline(rumf);
none:
	(void) fclose(rumf);
}

static int
used(int i)
{
	return(usedbits[i/CHARSZ] & (1 << (i % CHARSZ)));
}