2.11BSD/src/games/snake/snake.c
/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
#if !defined(lint) && defined(DOSCCS)
char copyright[] =
"@(#) Copyright (c) 1980 Regents of the University of California.\n\
All rights reserved.\n";
static char sccsid[] = "@(#)snake.c 5.1.1 (2.11BSD) 1997/7/29";
#endif
/*
* snake - crt hack game.
*
* You move around the screen with arrow keys trying to pick up money
* without getting eaten by the snake. hjkl work as in vi in place of
* arrow keys. You can leave at the exit any time.
*
* compile as follows:
* cc -O snake.c move.c -o snake -lm -ltermlib
*/
#include "snake.h"
#include <pwd.h>
/*
* If CHECKBUSY is defined, the file BUSY must be executable
* and must return a value which is used to determine the priority
* a which snake runs. A zero value means no nice.
* If BUSY does not exist, snake won't play.
*/
#ifndef BUSY
#define BUSY "/usr/games/lib/busy"
#endif
/*
* This is the data file for scorekeeping.
*/
#ifndef SNAKERAWSCORES
#define SNAKERAWSCORES "/usr/games/lib/snakerawscores"
#endif
/*
* If it exists, a log is kept here. Otherwise it isn't.
*/
#ifndef LOGFILE
#define LOGFILE "/usr/games/lib/snake.log"
#endif
#define PENALTY 10 /* % penalty for invoking spacewarp */
#define EOT '\004'
#define LF '\n'
#define DEL '\177'
#define ME 'I'
#define SNAKEHEAD 'S'
#define SNAKETAIL 's'
#define TREASURE '$'
#define GOAL '#'
#define BSIZE 80
struct point you;
struct point money;
struct point finish;
struct point snake[6];
int loot, penalty;
int long tl, tm=0L;
int argcount;
char **argval;
int moves;
static char str[BSIZE];
char stri[BSIZE];
char *p;
char ch, savec;
char *kl, *kr, *ku, *kd;
int fast=1;
int repeat=1;
long tv;
char *tn;
main(argc,argv)
int argc;
char **argv;
{
int i,k;
int j;
long time();
int stop();
char stdbuf[BUFSIZ];
argcount = argc;
argval = argv;
penalty = loot = 0;
getcap();
ccnt -= 2; lcnt -= 2; /* compensate for border */
busy();
time(&tv);
for (i=1; i<argc; i++) {
switch(argv[i][1]) {
case 'd':
sscanf(argv[1], "-d%ld", &tv);
break;
case 'w': /* width */
case 'c': /* columns */
ccnt = atoi(argv[i]+2);
break;
case 'l': /* length */
case 'h': /* height */
case 'r': /* rows */
lcnt = atoi(argv[i]+2);
break;
default:
printf("bad option %s\n", argv[1]);
}
}
srand((int)tv);
setbuf(stdout, stdbuf);
i = ((lcnt < ccnt) ? lcnt : ccnt); /* min screen edge */
if (i < 4) {
printf("Screen too small for a fair game\n");
done();
}
/*
* chunk is the amount of money the user gets for each $.
* The formula below tries to be fair for various screen sizes.
* We only pay attention to the smaller of the 2 edges, since
* that seems to be the bottleneck.
* This formula is a hyperbola which includes the following points:
* (24, $25) (original scoring algorithm)
* (12, $40) (experimentally derived by the "feel")
* (48, $15) (a guess)
* This will give a 4x4 screen $99/shot. We don't allow anything
* smaller than 4x4 because there is a 3x3 game where you can win
* an infinite amount of money.
*/
if (i < 12) i = 12; /* otherwise it isn't fair */
/*
* Compensate for border. This really changes the game since
* the screen is two squares smaller but we want the default
* to be $25, and the high scores on small screens were a bit
* much anyway.
*/
i += 2;
chunk = (675.0 / (i+6)) + 2.5; /* min screen edge */
signal (SIGINT, stop);
putpad(TI); /* String to begin programs that use cm */
putpad(KS); /* Put terminal in keypad transmit mode */
random(&finish);
random(&you);
random(&money);
random(&snake[0]);
if ((orig.sg_ospeed < B9600) ||
((! CM) && (! TA))) fast=0;
for(i=1;i<6;i++)
chase (&snake[i], &snake[i-1]);
setup();
mainloop();
}
/* Main command loop */
mainloop()
{
int j, k;
for (;;) {
int c,lastc,match;
move(&you);
fflush(stdout);
if (((c = getchar() & 0177) <= '9') && (c >= '0')) {
ungetc(c,stdin);
j = scanf("%d",&repeat);
c = getchar() & 0177;
} else {
if (c != '.') repeat = 1;
}
if (c == '.') {
c = lastc;
}
if ((Klength > 0) &&
(c == *KL || c == *KR || c == *KU || c == *KD)) {
savec = c;
match = 0;
kl = KL;
kr = KR;
ku = KU;
kd = KD;
for (j=Klength;j>0;j--){
if (match != 1) {
match = 0;
if (*kl++ == c) {
ch = 'h';
match++;
}
if (*kr++ == c) {
ch = 'l';
match++;
}
if (*ku++ == c) {
ch = 'k';
match++;
}
if (*kd++ == c) {
ch = 'j';
match++;
}
if (match == 0) {
ungetc(c,stdin);
ch = savec;
/* Oops!
* This works if we figure it out on second character.
*/
break;
}
}
savec = c;
if(j != 1) c = getchar() & 0177;
}
c = ch;
}
if (!fast) flushi();
lastc = c;
switch (c){
case CTRL(z):
case CTRL(c):
suspend();
continue;
case EOT:
case 'x':
case 0177: /* del or end of file */
ll();
length(moves);
logit("quit");
done();
case '!':
cook();
putchar('\n');
putchar(c);
fflush(stdout);
j = read(0,stri,BSIZE);
stri[j] = 0;
if (fork() == 0) {
setuid(getuid());
system(stri);
} else
wait(0);
printf("READY?\n");
fflush(stdout);
raw();
c = getchar();
ungetc(c,stdin);
putpad(KS);
putpad(TI);
point(&cursor,0,lcnt-1);
case CTRL(l):
setup();
winnings(cashvalue);
continue;
case 'p':
case 'd':
snap();
continue;
case 'w':
spacewarp(0);
continue;
case 'A':
repeat = you.col;
c = 'h';
break;
case 'H':
case 'S':
repeat = you.col - money.col;
c = 'h';
break;
case 'T':
repeat = you.line;
c = 'k';
break;
case 'K':
case 'E':
repeat = you.line - money.line;
c = 'k';
break;
case 'P':
repeat = ccnt - 1 - you.col;
c = 'l';
break;
case 'L':
case 'F':
repeat = money.col - you.col;
c = 'l';
break;
case 'B':
repeat = lcnt - 1 - you.line;
c = 'j';
break;
case 'J':
case 'C':
repeat = money.line - you.line;
c = 'j';
break;
}
for(k=1;k<=repeat;k++){
moves++;
switch(c) {
case 's':
case 'h':
case '\b':
if (you.col >0) {
if((fast)||(k == 1))
pchar(&you,' ');
you.col--;
if((fast) || (k == repeat) ||
(you.col == 0))
pchar(&you,ME);
}
break;
case 'f':
case 'l':
case ' ':
if (you.col < ccnt-1) {
if((fast)||(k == 1))
pchar(&you,' ');
you.col++;
if((fast) || (k == repeat) ||
(you.col == ccnt-1))
pchar(&you,ME);
}
break;
case CTRL(p):
case 'e':
case 'k':
case 'i':
if (you.line > 0) {
if((fast)||(k == 1))
pchar(&you,' ');
you.line--;
if((fast) || (k == repeat) ||
(you.line == 0))
pchar(&you,ME);
}
break;
case CTRL(n):
case 'c':
case 'j':
case LF:
case 'm':
if (you.line+1 < lcnt) {
if((fast)||(k == 1))
pchar(&you,' ');
you.line++;
if((fast) || (k == repeat) ||
(you.line == lcnt-1))
pchar(&you,ME);
}
break;
}
if (same(&you,&money))
{
char xp[20];
struct point z;
loot += 25;
if(k < repeat)
pchar(&you,' ');
do {
random(&money);
} while (money.col == finish.col && money.line == finish.line ||
money.col < 5 && money.line == 0 ||
money.col == you.col && money.line == you.line);
pchar(&money,TREASURE);
winnings(cashvalue);
continue;
}
if (same(&you,&finish))
{
win(&finish);
ll();
cook();
printf("You have won with $%d.\n",cashvalue);
fflush(stdout);
logit("won");
post(cashvalue,0);
length(moves);
done(0);
}
if (pushsnake())break;
}
fflush(stdout);
}
}
setup(){ /*
* setup the board
*/
int i;
clear();
pchar(&you,ME);
pchar(&finish,GOAL);
pchar(&money,TREASURE);
for(i=1; i<6; i++) {
pchar(&snake[i],SNAKETAIL);
}
pchar(&snake[0], SNAKEHEAD);
drawbox();
fflush(stdout);
}
drawbox()
{
register int i;
struct point p;
p.line = -1;
for (i= 0; i<ccnt; i++) {
p.col = i;
pchar(&p, '-');
}
p.col = ccnt;
for (i= -1; i<=lcnt; i++) {
p.line = i;
pchar(&p, '|');
}
p.col = -1;
for (i= -1; i<=lcnt; i++) {
p.line = i;
pchar(&p, '|');
}
p.line = lcnt;
for (i= 0; i<ccnt; i++) {
p.col = i;
pchar(&p, '-');
}
}
random(sp)
struct point *sp;
{
register int issame;
struct point p;
register int i;
sp->col = sp->line = -1; /* impossible */
do {
issame = 0;
p.col = ((rand()>>8) & 0377)% ccnt;
p.line = ((rand()>>8) & 0377)% lcnt;
/* make sure it's not on top of something else */
if (p.line == 0 && p.col <5) issame++;
if(same(&p, &you)) issame++;
if(same(&p, &money)) issame++;
if(same(&p, &finish)) issame++;
for (i=0; i<5; i++)
if(same(&p, &snake[i])) issame++;
} while (issame);
*sp = p;
}
busy()
{
FILE *pip, *popen();
char c;
int b,r;
float a;
#ifdef CHECKBUSY
if (! strcmp (argval[0], "test")) return;
if ((access(BUSY,1) != 0) || (pip = popen(BUSY,"r")) == NULL){
printf("Sorry, no snake just now.\n");
done();
}
fscanf(pip,"%d",&b);
pclose(pip);
if (b > 20) {
printf("Sorry, the system is too heavily loaded right now.\n");
done();
}
nice(b);
#endif
}
post(iscore, flag)
int iscore, flag;
{
short score = iscore;
int rawscores;
short uid;
short oldbest=0;
short allbwho=0, allbscore=0;
struct passwd *p, *getpwuid();
/*
* Neg uid, 0, and 1 cannot have scores recorded.
*/
if ((uid=getuid()) > 1 && (rawscores=open(SNAKERAWSCORES,2))>=0) {
/* Figure out what happened in the past */
read(rawscores, &allbscore, sizeof(short));
read(rawscores, &allbwho, sizeof(short));
lseek(rawscores, ((long)uid)*sizeof(short), 0);
read(rawscores, &oldbest, sizeof(short));
if (flag) return (score > oldbest ? 1 : 0);
/* Update this jokers best */
if (score > oldbest) {
lseek(rawscores, ((long)uid)*sizeof(short), 0);
write(rawscores, &score, sizeof(short));
printf("You bettered your previous best of $%d\n", oldbest);
} else
printf("Your best to date is $%d\n", oldbest);
/* See if we have a new champ */
p = getpwuid(allbwho);
if (p == NULL || score > allbscore) {
lseek(rawscores, (long)0, 0);
write(rawscores, &score, sizeof(short));
write(rawscores, &uid, sizeof(short));
if (p != NULL)
printf("You beat %s's old record of $%d!\n", p->pw_name, allbscore);
else
printf("You set a new record!\n");
} else
printf("The highest is %s with $%d\n", p->pw_name, allbscore);
close(rawscores);
} else
if (!flag)
printf("Unable to post score.\n");
return (1);
}
/*
* Flush typeahead to keep from buffering a bunch of chars and then
* overshooting. This loses horribly at 9600 baud, but works nicely
* if the terminal gets behind.
*/
flushi()
{
stty(0, &new);
}
int mx [8] = {
0, 1, 1, 1, 0,-1,-1,-1};
int my [8] = {
-1,-1, 0, 1, 1, 1, 0,-1};
float absv[8]= {
1, 1.4, 1, 1.4, 1, 1.4, 1, 1.4
};
int oldw=0;
chase (np, sp)
struct point *sp, *np;
{
/* this algorithm has bugs; otherwise the
snake would get too good */
struct point d;
int w, i, wt[8];
double sqrt(), v1, v2, vp, max;
point(&d,you.col-sp->col,you.line-sp->line);
v1 = sqrt( (double) (d.col*d.col + d.line*d.line) );
w=0;
max=0;
for(i=0; i<8; i++)
{
vp = d.col*mx[i] + d.line*my[i];
v2 = absv[i];
if (v1>0)
vp = ((double)vp)/(v1*v2);
else vp=1.0;
if (vp>max)
{
max=vp;
w=i;
}
}
for(i=0; i<8; i++)
{
point(&d,sp->col+mx[i],sp->line+my[i]);
wt[i]=0;
if (d.col<0 || d.col>=ccnt || d.line<0 || d.line>=lcnt)
continue;
if (d.line == 0 && d.col < 5) continue;
if (same(&d,&money)) continue;
if (same(&d,&finish)) continue;
wt[i]= i==w ? loot/10 : 1;
if (i==oldw) wt [i] += loot/20;
}
for(w=i=0; i<8; i++)
w+= wt[i];
vp = (( rand() >> 6 ) & 01777) %w;
for(i=0; i<8; i++)
if (vp <wt[i])
break;
else
vp -= wt[i];
if (i==8) {
printf("failure\n");
i=0;
while (wt[i]==0) i++;
}
oldw=w=i;
point(np,sp->col+mx[w],sp->line+my[w]);
}
spacewarp(w)
int w;{
struct point p;
int j;
random(&you);
point(&p,COLUMNS/2 - 8,LINES/2 - 1);
if (p.col < 0)
p.col = 0;
if (p.line < 0)
p.line = 0;
if (w) {
sprintf(str,"BONUS!!!");
loot = loot - penalty;
penalty = 0;
} else {
sprintf(str,"SPACE WARP!!!");
penalty += loot/PENALTY;
}
for(j=0;j<3;j++){
clear();
delay(5);
aprintf(&p,str);
delay(10);
}
setup();
winnings(cashvalue);
}
snap()
{
struct point p;
int i;
if(you.line < 3){
pchar(point(&p,you.col,0),'-');
}
if(you.line > lcnt-4){
pchar(point(&p,you.col,lcnt-1),'_');
}
if(you.col < 10){
pchar(point(&p,0,you.line),'(');
}
if(you.col > ccnt-10){
pchar(point(&p,ccnt-1,you.line),')');
}
if (! stretch(&money)) if (! stretch(&finish)) delay(10);
if(you.line < 3){
point(&p,you.col,0);
remove(&p);
}
if(you.line > lcnt-4){
point(&p,you.col,lcnt-1);
remove(&p);
}
if(you.col < 10){
point(&p,0,you.line);
remove(&p);
}
if(you.col > ccnt-10){
point(&p,ccnt-1,you.line);
remove(&p);
}
fflush(stdout);
}
stretch(ps)
struct point *ps;{
struct point p;
point(&p,you.col,you.line);
if(abs(ps->col-you.col) < 6){
if(you.line < ps->line){
for (p.line = you.line+1;p.line <= ps->line;p.line++)
pchar(&p,'v');
delay(10);
for (;p.line > you.line;p.line--)
remove(&p);
} else {
for (p.line = you.line-1;p.line >= ps->line;p.line--)
pchar(&p,'^');
delay(10);
for (;p.line < you.line;p.line++)
remove(&p);
}
return(1);
} else if(abs(ps->line-you.line) < 3){
p.line = you.line;
if(you.col < ps->col){
for (p.col = you.col+1;p.col <= ps->col;p.col++)
pchar(&p,'>');
delay(10);
for (;p.col > you.col;p.col--)
remove(&p);
} else {
for (p.col = you.col-1;p.col >= ps->col;p.col--)
pchar(&p,'<');
delay(10);
for (;p.col < you.col;p.col++)
remove(&p);
}
return(1);
}
return(0);
}
surround(ps)
struct point *ps;{
struct point x;
int i,j;
if(ps->col == 0)ps->col++;
if(ps->line == 0)ps->line++;
if(ps->line == LINES -1)ps->line--;
if(ps->col == COLUMNS -1)ps->col--;
aprintf(point(&x,ps->col-1,ps->line-1),"/*\\\r* *\r\\*/");
for (j=0;j<20;j++){
pchar(ps,'@');
delay(1);
pchar(ps,' ');
delay(1);
}
if (post(cashvalue,1)) {
aprintf(point(&x,ps->col-1,ps->line-1)," \ro.o\r\\_/");
delay(6);
aprintf(point(&x,ps->col-1,ps->line-1)," \ro.-\r\\_/");
delay(6);
}
aprintf(point(&x,ps->col-1,ps->line-1)," \ro.o\r\\_/");
}
win(ps)
struct point *ps;
{
struct point x;
int j,k;
int boxsize; /* actually diameter of box, not radius */
boxsize = fast ? 10 : 4;
point(&x,ps->col,ps->line);
for(j=1;j<boxsize;j++){
for(k=0;k<j;k++){
pchar(&x,'#');
x.line--;
}
for(k=0;k<j;k++){
pchar(&x,'#');
x.col++;
}
j++;
for(k=0;k<j;k++){
pchar(&x,'#');
x.line++;
}
for(k=0;k<j;k++){
pchar(&x,'#');
x.col--;
}
}
fflush(stdout);
}
pushsnake()
{
int i, bonus;
int issame = 0;
/*
* My manual says times doesn't return a value. Furthermore, the
* snake should get his turn every time no matter if the user is
* on a fast terminal with typematic keys or not.
* So I have taken the call to times out.
*/
for(i=4; i>=0; i--)
if (same(&snake[i], &snake[5]))
issame++;
if (!issame)
pchar(&snake[5],' ');
for(i=4; i>=0; i--)
snake[i+1]= snake[i];
chase(&snake[0], &snake[1]);
pchar(&snake[1],SNAKETAIL);
pchar(&snake[0],SNAKEHEAD);
for(i=0; i<6; i++)
{
if (same(&snake[i],&you))
{
surround(&you);
i = (cashvalue) % 10;
bonus = ((rand()>>8) & 0377)% 10;
ll();
printf("%d\n", bonus);
delay(30);
if (bonus == i) {
spacewarp(1);
logit("bonus");
flushi();
return(1);
}
if ( loot >= penalty ){
printf("You and your $%d have been eaten\n",cashvalue);
} else {
printf("The snake ate you. You owe $%d.\n",-cashvalue);
}
logit("eaten");
length(moves);
done();
}
}
return(0);
}
remove(sp)
struct point *sp;
{
int j;
if (same(sp,&money)) {
pchar(sp,TREASURE);
return(2);
}
if (same(sp,&finish)) {
pchar(sp,GOAL);
return(3);
}
if (same(sp,&snake[0])) {
pchar(sp,SNAKEHEAD);
return(4);
}
for(j=1;j<6;j++){
if(same(sp,&snake[j])){
pchar(sp,SNAKETAIL);
return(4);
}
}
if ((sp->col < 4) && (sp->line == 0)){
winnings(cashvalue);
if((you.line == 0) && (you.col < 4)) pchar(&you,ME);
return(5);
}
if (same(sp,&you)) {
pchar(sp,ME);
return(1);
}
pchar(sp,' ');
return(0);
}
winnings(won)
int won;
{
struct point p;
p.line = p.col = 1;
if(won>0){
move(&p);
printf("$%d",won);
}
}
stop(){
signal(SIGINT,1);
ll();
length(moves);
done();
}
suspend()
{
char *sh;
cook();
#ifdef SIGTSTP
kill(getpid(), SIGTSTP);
#else
sh = getenv("SHELL");
if (sh == NULL)
sh = "/bin/sh";
system(sh);
#endif
raw();
setup();
winnings(cashvalue);
}
length(num)
int num;
{
printf("You made %d moves.\n",num);
}
logit(msg)
char *msg;
{
FILE *logfile;
long t;
if ((logfile=fopen(LOGFILE, "a")) != NULL) {
time(&t);
fprintf(logfile, "%s $%d %dx%d %s %s", getlogin(), cashvalue, lcnt, ccnt, msg, ctime(&t));
fclose(logfile);
}
}