1/*	$OpenBSD: hack.unix.c,v 1.23 2023/09/06 11:53:56 jsg 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/* This file collects some Unix dependencies; hack.pager.c contains some more */
65
66/*
67 * The time is used for:
68 *	- seed for random()
69 *	- year on tombstone and yymmdd in record file
70 *	- phase of the moon (various monsters react to NEW_MOON or FULL_MOON)
71 *	- night and midnight (the undead are dangerous at midnight)
72 *	- determination of what files are "very old"
73 */
74
75#include <sys/stat.h>
76
77#include <err.h>
78#include <errno.h>
79#include <limits.h>
80#include <signal.h>
81#include <stdio.h>
82#include <stdlib.h>
83#include <time.h>
84#include <unistd.h>
85
86#include "hack.h"
87
88
89static struct tm *getlt(void);
90static int veryold(int);
91#ifdef MAIL
92static void newmail(void);
93static void mdrush(struct monst *, boolean);
94#endif
95
96static struct tm *
97getlt(void)
98{
99	time_t date;
100
101	(void) time(&date);
102	return(localtime(&date));
103}
104
105int
106getyear(void)
107{
108	return(1900 + getlt()->tm_year);
109}
110
111char *
112getdate(void)
113{
114	static char datestr[7];
115	struct tm *lt = getlt();
116
117	(void) snprintf(datestr, sizeof(datestr), "%02d%02d%02d",
118		lt->tm_year % 100, lt->tm_mon + 1, lt->tm_mday);
119	return(datestr);
120}
121
122/*
123 * 0-7, with 0: new, 4: full
124 * moon period: 29.5306 days
125 * year: 365.2422 days
126 */
127int
128phase_of_the_moon(void)
129{
130	struct tm *lt = getlt();
131	int epact, diy, golden;
132
133	diy = lt->tm_yday;
134	golden = (lt->tm_year % 19) + 1;
135	epact = (11 * golden + 18) % 30;
136	if ((epact == 25 && golden > 11) || epact == 24)
137		epact++;
138
139	return( (((((diy + epact) * 6) + 11) % 177) / 22) & 7 );
140}
141
142int
143night(void)
144{
145	int hour = getlt()->tm_hour;
146
147	return(hour < 6 || hour > 21);
148}
149
150int
151midnight(void)
152{
153	return(getlt()->tm_hour == 0);
154}
155
156struct stat buf;
157
158/* see whether we should throw away this xlock file */
159static int
160veryold(int fd)
161{
162	int i;
163	time_t date;
164
165	if(fstat(fd, &buf)) return(0);			/* cannot get status */
166	if(buf.st_size != sizeof(int)) return(0);	/* not an xlock file */
167	(void) time(&date);
168	if(date - buf.st_mtime < 3L*24L*60L*60L) {	/* recent */
169		int lockedpid;	/* should be the same size as hackpid */
170
171		if(read(fd, (char *)&lockedpid, sizeof(lockedpid)) !=
172			sizeof(lockedpid))
173			/* strange ... */
174			return(0);
175
176		/* From: Rick Adams <seismo!rick>
177		   This will work on 4.1cbsd, 4.2bsd and system 3? & 5.
178		   It will do nothing on V7 or 4.1bsd. */
179		if(!(kill(lockedpid, 0) == -1 && errno == ESRCH))
180			return(0);
181	}
182	(void) close(fd);
183	for(i = 1; i <= MAXLEVEL; i++) {		/* try to remove all */
184		glo(i);
185		(void) unlink(lock);
186	}
187	glo(0);
188	if(unlink(lock)) return(0);			/* cannot remove it */
189	return(1);					/* success! */
190}
191
192void
193getlock(void)
194{
195	extern int hackpid, locknum;
196	int i = 0, fd;
197
198	(void) fflush(stdout);
199
200	/* we ignore QUIT and INT at this point */
201	if (link(HLOCK, LLOCK) == -1) {
202		int errnosv = errno;
203
204		perror(HLOCK);
205		printf("Cannot link %s to %s\n", LLOCK, HLOCK);
206		switch(errnosv) {
207		case ENOENT:
208		    printf("Perhaps there is no (empty) file %s ?\n", HLOCK);
209		    break;
210		case EACCES:
211		    printf("It seems you don't have write permission here.\n");
212		    break;
213		case EEXIST:
214		    printf("(Try again or rm %s.)\n", LLOCK);
215		    break;
216		default:
217		    printf("I don't know what is wrong.");
218		}
219		getret();
220		error("");
221	}
222
223	regularize(lock);
224	glo(0);
225	if(locknum > 25) locknum = 25;
226
227	do {
228		if(locknum) lock[0] = 'a' + i++;
229
230		if((fd = open(lock, O_RDONLY)) == -1) {
231			if(errno == ENOENT) goto gotlock;    /* no such file */
232			perror(lock);
233			(void) unlink(LLOCK);
234			error("Cannot open %s", lock);
235		}
236
237		if(veryold(fd))	/* if true, this closes fd and unlinks lock */
238			goto gotlock;
239		(void) close(fd);
240	} while(i < locknum);
241
242	(void) unlink(LLOCK);
243	error(locknum ? "Too many hacks running now."
244		      : "There is a game in progress under your name.");
245gotlock:
246	fd = open(lock, O_CREAT | O_TRUNC | O_WRONLY, FMASK);
247	if(unlink(LLOCK) == -1)
248		error("Cannot unlink %s.", LLOCK);
249	if(fd == -1) {
250		error("cannot creat lock file.");
251	} else {
252		if(write(fd, (char *) &hackpid, sizeof(hackpid))
253		    != sizeof(hackpid)){
254			error("cannot write lock");
255		}
256		if(close(fd) == -1) {
257			error("cannot close lock");
258		}
259	}
260}
261
262#ifdef MAIL
263
264/*
265 * Notify user when new mail has arrived. [Idea from Merlyn Leroy, but
266 * I don't know the details of his implementation.]
267 * { Later note: he disliked my calling a general mailreader and felt that
268 *   hack should do the paging itself. But when I get mail, I want to put it
269 *   in some folder, reply, etc. - it would be unreasonable to put all these
270 *   functions in hack. }
271 * The mail daemon '2' is at present not a real monster, but only a visual
272 * effect. Thus, makemon() is superfluous. This might become otherwise,
273 * however. The motion of '2' is less restrained than usual: diagonal moves
274 * from a DOOR are possible. He might also use SDOOR's. Also, '2' is visible
275 * in a ROOM, even when you are Blind.
276 * Its path should be longer when you are Telepat-hic and Blind.
277 *
278 * Interesting side effects:
279 *	- You can get rich by sending yourself a lot of mail and selling
280 *	  it to the shopkeeper. Unfortunately mail isn't very valuable.
281 *	- You might die in case '2' comes along at a critical moment during
282 *	  a fight and delivers a scroll the weight of which causes you to
283 *	  collapse.
284 *
285 * Possible extensions:
286 *	- Open the file MAIL and do fstat instead of stat for efficiency.
287 *	  (But sh uses stat, so this cannot be too bad.)
288 *	- Examine the mail and produce a scroll of mail called "From somebody".
289 *	- Invoke MAILREADER in such a way that only this single letter is read.
290 *
291 *	- Make him lose his mail when a Nymph steals the letter.
292 *	- Do something to the text when the scroll is enchanted or cancelled.
293 */
294static struct stat omstat,nmstat;
295static char *mailbox;
296static long laststattime;
297
298void
299getmailstatus(void)
300{
301	if(!(mailbox = getenv("MAIL")))
302		return;
303	if(stat(mailbox, &omstat)){
304#ifdef PERMANENT_MAILBOX
305		pline("Cannot get status of MAIL=%s .", mailbox);
306		mailbox = 0;
307#else
308		omstat.st_mtime = 0;
309#endif /* PERMANENT_MAILBOX */
310	}
311}
312
313void
314ckmailstatus(void)
315{
316	if(!mailbox
317#ifdef MAILCKFREQ
318		    || moves < laststattime + MAILCKFREQ
319#endif /* MAILCKFREQ */
320							)
321		return;
322	laststattime = moves;
323	if(stat(mailbox, &nmstat)){
324#ifdef PERMANENT_MAILBOX
325		pline("Cannot get status of MAIL=%s anymore.", mailbox);
326		mailbox = 0;
327#else
328		nmstat.st_mtime = 0;
329#endif /* PERMANENT_MAILBOX */
330	} else if(nmstat.st_mtime > omstat.st_mtime) {
331		if(nmstat.st_size)
332			newmail();
333		getmailstatus();	/* might be too late ... */
334	}
335}
336
337static void
338newmail(void)
339{
340	/* produce a scroll of mail */
341	struct obj *obj;
342	struct monst *md;
343	extern char plname[];
344	extern struct obj *mksobj();
345	extern struct monst *makemon();
346	extern struct permonst pm_mail_daemon;
347
348	obj = mksobj(SCR_MAIL);
349	if(md = makemon(&pm_mail_daemon, u.ux, u.uy)) /* always succeeds */
350		mdrush(md,0);
351
352	pline("\"Hello, %s! I have some mail for you.\"", plname);
353	if(md) {
354		if(dist(md->mx,md->my) > 2)
355			pline("\"Catch!\"");
356		more();
357
358		/* let him disappear again */
359		mdrush(md,1);
360		mondead(md);
361	}
362
363	obj = addinv(obj);
364	(void) identify(obj);		/* set known and do prinv() */
365}
366
367/* make md run through the cave */
368static void
369mdrush(struct monst *md, boolean away)
370{
371	int uroom = inroom(u.ux, u.uy);
372	if(uroom >= 0) {
373		int tmp = rooms[uroom].fdoor;
374		int cnt = rooms[uroom].doorct;
375		int fx = u.ux, fy = u.uy;
376		while(cnt--) {
377			if(dist(fx,fy) < dist(doors[tmp].x, doors[tmp].y)){
378				fx = doors[tmp].x;
379				fy = doors[tmp].y;
380			}
381			tmp++;
382		}
383		tmp_at(-1, md->data->mlet);	/* open call */
384		if(away) {	/* interchange origin and destination */
385			unpmon(md);
386			tmp = fx; fx = md->mx; md->mx = tmp;
387			tmp = fy; fy = md->my; md->my = tmp;
388		}
389		while(fx != md->mx || fy != md->my) {
390			int dx,dy,nfx = fx,nfy = fy,d1,d2;
391
392			tmp_at(fx,fy);
393			d1 = DIST(fx,fy,md->mx,md->my);
394			for(dx = -1; dx <= 1; dx++) for(dy = -1; dy <= 1; dy++)
395			    if(dx || dy) {
396				d2 = DIST(fx+dx,fy+dy,md->mx,md->my);
397				if(d2 < d1) {
398				    d1 = d2;
399				    nfx = fx+dx;
400				    nfy = fy+dy;
401				}
402			    }
403			if(nfx != fx || nfy != fy) {
404			    fx = nfx;
405			    fy = nfy;
406			} else {
407			    if(!away) {
408				md->mx = fx;
409				md->my = fy;
410			    }
411			    break;
412			}
413		}
414		tmp_at(-1,-1);			/* close call */
415	}
416	if(!away)
417		pmon(md);
418}
419
420void
421readmail(void)
422{
423#ifdef DEF_MAILREADER			/* This implies that UNIX is defined */
424	char *mr = 0;
425	more();
426	if(!(mr = getenv("MAILREADER")))
427		mr = DEF_MAILREADER;
428	if(child(1)){
429		execl(mr, mr, (char *)NULL);
430		exit(1);
431	}
432#else /* DEF_MAILREADER */
433	(void) page_file(mailbox, FALSE);
434#endif /* DEF_MAILREADER */
435	/* get new stat; not entirely correct: there is a small time
436	   window where we do not see new mail */
437	getmailstatus();
438}
439#endif /* MAIL */
440
441/* normalize file name - we don't like ..'s or /'s */
442void
443regularize(char *s)
444{
445	char *lp;
446
447	while((lp = strchr(s, '.')) || (lp = strchr(s, '/')))
448		*lp = '_';
449}
450