usr/src/games/hack/hack.unix.c

/* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
/* hack.unix.c - version 1.0.3 */

/* This file collects some Unix dependencies; hack.pager.c contains some more */

/*
 * The time is used for:
 *      - seed for random()
 *      - year on tombstone and yymmdd in record file
 *      - phase of the moon (various monsters react to NEW_MOON or FULL_MOON)
 *      - night and midnight (the undead are dangerous at midnight)
 *      - determination of what files are "very old"
 */

#include <stdio.h>
#include <errno.h>
#include "hack.h"       /* mainly for index() which depends on BSD */

#include        <sys/types.h>           /* for time_t and stat */
#include        <sys/stat.h>
#ifdef BSD
#include        <sys/time.h>
#else
#include        <time.h>
#endif BSD

extern char *getenv();
extern time_t time();

setrandom()
{
        (void) srandom((int) time ((time_t *) 0));
}

struct tm *
getlt()
{
        time_t date;
        struct tm *localtime();

        (void) time(&date);
        return(localtime(&date));
}

getyear()
{
        return(1900 + getlt()->tm_year);
}

char *
getdate()
{
        static char datestr[7];
        register struct tm *lt = getlt();

        (void) sprintf(datestr, "%2d%2d%2d",
                lt->tm_year, lt->tm_mon + 1, lt->tm_mday);
        if(datestr[2] == ' ') datestr[2] = '0';
        if(datestr[4] == ' ') datestr[4] = '0';
        return(datestr);
}

phase_of_the_moon()                     /* 0-7, with 0: new, 4: full */
{                                       /* moon period: 29.5306 days */
                                        /* year: 365.2422 days */
        register struct tm *lt = getlt();
        register int epact, diy, golden;

        diy = lt->tm_yday;
        golden = (lt->tm_year % 19) + 1;
        epact = (11 * golden + 18) % 30;
        if ((epact == 25 && golden > 11) || epact == 24)
                epact++;

        return( (((((diy + epact) * 6) + 11) % 177) / 22) & 7 );
}

night()
{
        register int hour = getlt()->tm_hour;

        return(hour < 6 || hour > 21);
}

midnight()
{
        return(getlt()->tm_hour == 0);
}

struct stat buf, hbuf;

gethdate(name) char *name; {
/* old version - for people short of space */
/*
/* register char *np;
/*      if(stat(name, &hbuf))
/*              error("Cannot get status of %s.",
/*                      (np = rindex(name, '/')) ? np+1 : name);
/*
/* version using PATH from: seismo!gregc@ucsf-cgl.ARPA (Greg Couch) */


/*
 * The problem with   #include  <sys/param.h>   is that this include file
 * does not exist on all systems, and moreover, that it sometimes includes
 * <sys/types.h> again, so that the compiler sees these typedefs twice.
 */
#define         MAXPATHLEN      1024

register char *np, *path;
char filename[MAXPATHLEN+1];
        if (index(name, '/') != NULL || (path = getenv("PATH")) == NULL)
                path = "";

        for (;;) {
                if ((np = index(path, ':')) == NULL)
                        np = path + strlen(path);       /* point to end str */
                if (np - path <= 1)                     /* %% */
                        (void) strcpy(filename, name);
                else {
                        (void) strncpy(filename, path, np - path);
                        filename[np - path] = '/';
                        (void) strcpy(filename + (np - path) + 1, name);
                }
                if (stat(filename, &hbuf) == 0)
                        return;
                if (*np == '\0')
                        break;
                path = np + 1;
        }
        error("Cannot get status of %s.",
                (np = rindex(name, '/')) ? np+1 : name);
}

uptodate(fd) {
        if(fstat(fd, &buf)) {
                pline("Cannot get status of saved level? ");
                return(0);
        }
        if(buf.st_mtime < hbuf.st_mtime) {
                pline("Saved level is out of date. ");
                return(0);
        }
        return(1);
}

/* see whether we should throw away this xlock file */
veryold(fd) {
        register int i;
        time_t date;

        if(fstat(fd, &buf)) return(0);                  /* cannot get status */
        if(buf.st_size != sizeof(int)) return(0);       /* not an xlock file */
        (void) time(&date);
        if(date - buf.st_mtime < 3L*24L*60L*60L) {      /* recent */
                extern int errno;
                int lockedpid;  /* should be the same size as hackpid */

                if(read(fd, (char *)&lockedpid, sizeof(lockedpid)) !=
                        sizeof(lockedpid))
                        /* strange ... */
                        return(0);

                /* From: Rick Adams <seismo!rick>
                /* This will work on 4.1cbsd, 4.2bsd and system 3? & 5.
                /* It will do nothing on V7 or 4.1bsd. */
                if(!(kill(lockedpid, 0) == -1 && errno == ESRCH))
                        return(0);
        }
        (void) close(fd);
        for(i = 1; i <= MAXLEVEL; i++) {                /* try to remove all */
                glo(i);
                (void) unlink(lock);
        }
        glo(0);
        if(unlink(lock)) return(0);                     /* cannot remove it */
        return(1);                                      /* success! */
}

getlock()
{
        extern int errno, hackpid, locknum;
        register int i = 0, fd;

        (void) fflush(stdout);

        /* we ignore QUIT and INT at this point */
        if (link(HLOCK, LLOCK) == -1) {
                register int errnosv = errno;

                perror(HLOCK);
                printf("Cannot link %s to %s\n", LLOCK, HLOCK);
                switch(errnosv) {
                case ENOENT:
                    printf("Perhaps there is no (empty) file %s ?\n", HLOCK);
                    break;
                case EACCES:
                    printf("It seems you don't have write permission here.\n");
                    break;
                case EEXIST:
                    printf("(Try again or rm %s.)\n", LLOCK);
                    break;
                default:
                    printf("I don't know what is wrong.");
                }
                getret();
                error("");
                /*NOTREACHED*/
        }

        regularize(lock);
        glo(0);
        if(locknum > 25) locknum = 25;

        do {
                if(locknum) lock[0] = 'a' + i++;

                if((fd = open(lock, 0)) == -1) {
                        if(errno == ENOENT) goto gotlock;    /* no such file */
                        perror(lock);
                        (void) unlink(LLOCK);
                        error("Cannot open %s", lock);
                }

                if(veryold(fd)) /* if true, this closes fd and unlinks lock */
                        goto gotlock;
                (void) close(fd);
        } while(i < locknum);

        (void) unlink(LLOCK);
        error(locknum ? "Too many hacks running now."
                      : "There is a game in progress under your name.");
gotlock:
        fd = creat(lock, FMASK);
        if(unlink(LLOCK) == -1)
                error("Cannot unlink %s.", LLOCK);
        if(fd == -1) {
                error("cannot creat lock file.");
        } else {
                if(write(fd, (char *) &hackpid, sizeof(hackpid))
                    != sizeof(hackpid)){
                        error("cannot write lock");
                }
                if(close(fd) == -1) {
                        error("cannot close lock");
                }
        }
}

#ifdef MAIL

/*
 * Notify user when new mail has arrived. [Idea from Merlyn Leroy, but
 * I don't know the details of his implementation.]
 * { Later note: he disliked my calling a general mailreader and felt that
 *   hack should do the paging itself. But when I get mail, I want to put it
 *   in some folder, reply, etc. - it would be unreasonable to put all these
 *   functions in hack. }
 * The mail daemon '2' is at present not a real monster, but only a visual
 * effect. Thus, makemon() is superfluous. This might become otherwise,
 * however. The motion of '2' is less restrained than usual: diagonal moves
 * from a DOOR are possible. He might also use SDOOR's. Also, '2' is visible
 * in a ROOM, even when you are Blind.
 * Its path should be longer when you are Telepat-hic and Blind.
 *
 * Interesting side effects:
 *      - You can get rich by sending yourself a lot of mail and selling
 *        it to the shopkeeper. Unfortunately mail isn't very valuable.
 *      - You might die in case '2' comes along at a critical moment during
 *        a fight and delivers a scroll the weight of which causes you to
 *        collapse.
 *
 * Possible extensions:
 *      - Open the file MAIL and do fstat instead of stat for efficiency.
 *        (But sh uses stat, so this cannot be too bad.)
 *      - Examine the mail and produce a scroll of mail called "From somebody".
 *      - Invoke MAILREADER in such a way that only this single letter is read.
 *
 *      - Make him lose his mail when a Nymph steals the letter.
 *      - Do something to the text when the scroll is enchanted or cancelled.
 */
#include        "def.mkroom.h"
static struct stat omstat,nmstat;
static char *mailbox;
static long laststattime;

getmailstatus() {
        if(!(mailbox = getenv("MAIL")))
                return;
        if(stat(mailbox, &omstat)){
#ifdef PERMANENT_MAILBOX
                pline("Cannot get status of MAIL=%s .", mailbox);
                mailbox = 0;
#else
                omstat.st_mtime = 0;
#endif PERMANENT_MAILBOX
        }
}

ckmailstatus() {
        if(!mailbox
#ifdef MAILCKFREQ
                    || moves < laststattime + MAILCKFREQ
#endif MAILCKFREQ
                                                        )
                return;
        laststattime = moves;
        if(stat(mailbox, &nmstat)){
#ifdef PERMANENT_MAILBOX
                pline("Cannot get status of MAIL=%s anymore.", mailbox);
                mailbox = 0;
#else
                nmstat.st_mtime = 0;
#endif PERMANENT_MAILBOX
        } else if(nmstat.st_mtime > omstat.st_mtime) {
                if(nmstat.st_size)
                        newmail();
                getmailstatus();        /* might be too late ... */
        }
}

newmail() {
        /* produce a scroll of mail */
        register struct obj *obj;
        register struct monst *md;
        extern char plname[];
        extern struct obj *mksobj(), *addinv();
        extern struct monst *makemon();
        extern struct permonst pm_mail_daemon;

        obj = mksobj(SCR_MAIL);
        if(md = makemon(&pm_mail_daemon, u.ux, u.uy)) /* always succeeds */
                mdrush(md,0);

        pline("\"Hello, %s! I have some mail for you.\"", plname);
        if(md) {
                if(dist(md->mx,md->my) > 2)
                        pline("\"Catch!\"");
                more();

                /* let him disappear again */
                mdrush(md,1);
                mondead(md);
        }

        obj = addinv(obj);
        (void) identify(obj);           /* set known and do prinv() */
}

/* make md run through the cave */
mdrush(md,away)
register struct monst *md;
boolean away;
{
        register int uroom = inroom(u.ux, u.uy);
        if(uroom >= 0) {
                register int tmp = rooms[uroom].fdoor;
                register int cnt = rooms[uroom].doorct;
                register int fx = u.ux, fy = u.uy;
                while(cnt--) {
                        if(dist(fx,fy) < dist(doors[tmp].x, doors[tmp].y)){
                                fx = doors[tmp].x;
                                fy = doors[tmp].y;
                        }
                        tmp++;
                }
                tmp_at(-1, md->data->mlet);     /* open call */
                if(away) {      /* interchange origin and destination */
                        unpmon(md);
                        tmp = fx; fx = md->mx; md->mx = tmp;
                        tmp = fy; fy = md->my; md->my = tmp;
                }
                while(fx != md->mx || fy != md->my) {
                        register int dx,dy,nfx = fx,nfy = fy,d1,d2;

                        tmp_at(fx,fy);
                        d1 = DIST(fx,fy,md->mx,md->my);
                        for(dx = -1; dx <= 1; dx++) for(dy = -1; dy <= 1; dy++)
                            if(dx || dy) {
                                d2 = DIST(fx+dx,fy+dy,md->mx,md->my);
                                if(d2 < d1) {
                                    d1 = d2;
                                    nfx = fx+dx;
                                    nfy = fy+dy;
                                }
                            }
                        if(nfx != fx || nfy != fy) {
                            fx = nfx;
                            fy = nfy;
                        } else {
                            if(!away) {
                                md->mx = fx;
                                md->my = fy;
                            }
                            break;
                        }
                }
                tmp_at(-1,-1);                  /* close call */
        }
        if(!away)
                pmon(md);
}

readmail() {
#ifdef DEF_MAILREADER                   /* This implies that UNIX is defined */
        register char *mr = 0;
        more();
        if(!(mr = getenv("MAILREADER")))
                mr = DEF_MAILREADER;
        if(child(1)){
                execl(mr, mr, (char *) 0);
                exit(1);
        }
#else DEF_MAILREADER
        (void) page_file(mailbox, FALSE);
#endif DEF_MAILREADER
        /* get new stat; not entirely correct: there is a small time
           window where we do not see new mail */
        getmailstatus();
}
#endif MAIL

regularize(s)   /* normalize file name - we don't like ..'s or /'s */
register char *s;
{
        register char *lp;

        while((lp = index(s, '.')) || (lp = index(s, '/')))
                *lp = '_';
}