I've gotten the original dds.c (the obfuscated one, not the one I posted) to compile with Borland C 5.5 and with gcc 2.95. It fails with anything later than v2.95.
The one I posted compiles with gcc.exe (tdm64-1) 9.2.0 and probably others.
Also, the author sent me an updated obfuscated version that compiles with 9.2.0.
Code: Select all
/*------------------------------------------------------------------------
Tiny BASIC for Tiny Star Trek. Based on dds.c from 1990 IOCCC
This is a modified version of the infamous DDS basic interpreter by Diomidis Spinellis.
Changes - Just enough to run Tiny Star Trek :-)
- Enough obfuscation removed to allow modifications
- All BASIC keywords are now lowercase
- Accepts command line input
- Added a single integer array: @
- Added the statement continuation character: ":"
- Added 'prompt' on input statement
- Enhanced print statement
- Added rnd(), asc() and abs() functions
- Converted the recursive descent expression parser to precedence climbing
- Enhanced 'if' to allow statements to follow
Supported:
old trek.bas
run, list, new, bye
save trek.bas
assignment, variables a to z, single array: @(index)
for var = exp to exp:next var
gosub exp:return
goto exp
input [prompt,] var
print [[#num ',' ] exp { ',' [#num ','] exp }] [','] {':' stmt} eol
rem any text
end, stop
if exp stmt
rnd(exp)
asc("x")
abs(exp)
system - exit immediately to the OS.
trace on|off
immediate mode
Tiny Star Trek:
5 y=2999:input "Do you want a difficult game? (y or n):", a
10 print "Stardate 3200: your mission is ",:if a=asc("y") y=999
15 k=0:b=0:d=30:for i=0 to 63:j=rnd(99)<5:b=b+j
20 m=rnd(y):m=(m<209)+(m<99)+(m<49)+(m<24)+(m<9)+(m<2):k=k+m
25 @(i)=-100*m-10*j-rnd(8):next i:if(b<2)+(k<4)goto 15
30 print "to destroy ",#1,k," Klingons in 30 stardates."
35 print "There are ",#1,b," Starbases.":gosub 160:c=0:h=k
40 u=rnd(8):v=rnd(8):x=rnd(8):y=rnd(8)
45 for i=71 to 152:@(i)=0:next i:@(8*x+y+62)=4:m=abs(@(8*u+v-9)):n=m/100
50 i=1:if n for j=1 to n:gosub 165:@(j+134)=300:@(j+140)=s:@(j+146)=t:next j
55 gosub 175:m=m-100*n:i=2:if m/10 gosub 165
60 m=m-m/10*10:i=3:if m for j=1 to m:gosub 165:next j
65 gosub 145:gosub 325:if k goto 95
70 print :print "Mission accomplished.":if d<3 print "Boy, you barely made it."
75 if d>5 print "Good work...":if d>9 print "Fantastic!":if d>13 print "Unbelievable!"
80 d=30-d:i=h*100/d*10:print #1,h," Klingons in ",d," stardates. (",i,")"
85 j=100*(c=0)-5*c:print #1,c," casualties incurred. (",j,")"
90 print "Your score:",i+j:goto 110
95 if d<0 print "It's too late, the federation has been conquered.":goto 110
100 if e>=0 goto 120
105 print "Enterprise destroyed":if h-k>9 print "But you were a good man"
110 y=987:print :input "Another game? (y or n):",a:if a=asc("y") goto 5
115 print "Good bye.":end
120 input "Captain? ",a
121 if a=asc("g") goto 180
122 if a=asc("l") goto 200
123 if a=asc("s") goto 220
124 if a=asc("p") goto 260
125 if a=asc("r") goto 420
126 if a=asc("w") goto 465
127 if a=asc("t") goto 555
128 if a=asc("q") goto 110
130 print "r=Report s=SR. sensor l=LR. sensor"
135 print "g=Galaxy map p=Phaser t=Torpedo"
140 print "w=Warp engine **please use one of these commands***":goto 120
145 for i=x-(x>1) to x+(x<8):for j=y-(y>1) to y+(y<8)
150 if@(8*i+j+62) <> 2 next j:next i:o=0:return
155 if o=0 print "Sulu: 'Captain, we are docked at Starbase.'"
160 e=4000:f=10:o=1:for i=64 to 70:@(i)=0:next i:return
165 s=rnd(8):t=rnd(8):a=8*s+t+62:if@(a)goto 165
170 @(a)=i:return
175 print "Enterprise in q-",#1,u,v," s-",x,y:return
180 gosub 175:j=2:gosub 375:if i goto 120
185 print " of galaxy map":for i=0 to 7:print :print #1,i+1,":",:for j=0 to 7:m=@(8*i+j)
190 print #4,(m>0)*m,:next j:print :next i:print " ",:for i=0 to 7:print " ..",:next i:print
195 print " ",:for i=1 to 8:print #4,i,:next i:print :print :goto 120
200 gosub 175:j=3:gosub 375:if i goto 120
205 print :for i=u-1 to u+1:for j=v-1 to v+1:m=8*i+j-9:a=0
210 if(i>0)*(i<9)*(j>0)*(j<9)a=abs(@(m)):@(m)=a
215 print #4,a,:next j:print :next i:goto 120
220 gosub 175:j=1:gosub 375:if i goto 120
225 m=8*u+v-9:@(m)=abs(@(m))
230 print :for i=1 to 8:print #1,i,:for j=1 to 8:m=@(8*i+j+62):if m=0 print " .",
235 if m=1 print " K",
240 if m=2 print " B",
245 if m=3 print " *",
250 if m=4 print " E",
255 next j:print :next i:print " ",:for i=1 to 8:print #2,i,:next i:print :goto 120
260 j=4:gosub 375:if i goto 120
265 input " energized. Units to fire:",a:if a<1 goto 120
270 if a>e print "Spock: 'We have only ",#1,e," units.'":goto 120
275 e=e-a:if n<1 print "Phaser fired at empty space.":goto 65
280 a=a/n:for m=135 to 140:if@(m)=0 goto 290
285 gosub 295:print #3,s," units hit ",:gosub 305
290 next m:goto 65
295 if a>1090 print "...overloaded..":j=4:@(67)=1:a=9:gosub 375
300 i=@(m+6)-x:j=@(m+12)-y:s=a*30/(30+i*i+j*j)+1:return
305 print "Klingon at s-",#1,@(m+6),@(m+12),:@(m)=@(m)-s
310 if@(m)>0 print " **damaged**":return
315 @(m)=0:i=8*u+v-9:j=@(i)/abs(@(i)):@(i)=@(i)-100*j:k=k-1
320 i=8*@(m+6)+@(m+12)+62:@(i)=0:n=n-1:print " ***destroyed***":return
325 if n=0 return
330 print "Klingon attack":if o print "Starbase protects Enterprise":return
335 t=0:for m=135 to 140:if@(m)=0 goto 350
340 a=(@(m)+rnd(@(m)))/2:gosub 295:t=t+s:i=@(m+6):j=@(m+12)
345 print #3,s," units hit from Klingon at s-",#1,i,j
350 next m:e=e-t:if e<=0 print "*** bang ***":return
355 print #1,e," units of energy left.":if rnd(e/4)>t return
360 if@(70)=0@(70)=rnd(t/50+1):j=7:goto 375
365 j=rnd(6):@(j+63)=rnd(t/99+1)+@(j+63):i=rnd(8)+1:c=c+i
370 print "McCoy: 'Sickbay to bridge, we suffered",#2,i," casualties.'"
375 i=@(j+63):if j=1 print "Short range sensor",
380 if j=2 print "Computer display",
385 if j=3 print "Long range sensor",
390 if j=4 print "Phaser",
395 if j=5 print "Warp engine",
400 if j=6 print "Photon torpedo tubes",
405 if j=7 print "Shield",
410 if i=0 return
415 print " damaged, ",#1,i," stardates estimated for repair":return
420 print "Status report:":print "Stardate",#10,3230-d:print "time left",#7,d
425 print "Condition ",:if o print "Docked":goto 445
430 if n print "Red":goto 445
435 if e<999 print "Yellow":goto 445
440 print "Green"
445 print "Position q-",#1,u,v," s-",x,y:print "Energy",#12,e
450 print "Torpedoes",#7,f:print "Klingons left",#3,k:print "Starbases",#6,b
455 for j=1 to 7:if@(j+63)gosub 375
460 next j:goto 120
465 j=5:gosub 375:if i=0 print
470 input "sector distance:",w:if w<1 goto 120
475 if i*(w>2)print "Chekov: 'We can try 2 at most, sir.'":goto 470
480 if w>91 w=91:print "Spock: 'Are you sure, Captain?'"
485 if e<w*w/2 print "Scotty: 'Sir, we do not have the energy.'":goto 120
490 gosub 615:if r=0 goto 120
495 d=d-1:e=e-w*w/2:@(8*x+y+62)=0
500 for m=64 to 70:@(m)=(@(m)-1)*(@(m)>0):next m
505 p=45*x+22:g=45*y+22:w=45*w:for m=1 to 8:w=w-r:if w<-22 goto 525
510 p=p+s:g=g+t:i=p/45:j=g/45:if(i<1)+(i>8)+(j<1)+(j>8)goto 530
515 if@(8*i+j+62)=0 x=i:y=j:next m
520 print "**Emergency stop**":print "Spock: 'To err is human.'"
525 @(8*x+y+62)=4:gosub 175:goto 65
530 p=u*72+p/5+w/5*s/r-9:u=p/72:g=v*72+g/5+w/5*t/r-9:v=g/72
535 if rnd(9)<2 print "***Space storm***":t=100:gosub 360
540 if(u>0)*(u<9)*(v>0)*(v<9)x=(p+9-72*u)/9:y=(g+9-72*v)/9:goto 45
545 print "**You wandered outside the galaxy**"
550 print "On board computer takes over, and saved your life":goto 40
555 j=6:gosub 375:if i goto 120
560 if f=0 print " empty":goto 120
565 print " loaded":gosub 615:if r=0 goto 120
570 print "Torpedo track ",:f=f-1:p=45*x+22:g=45*y+22:for m=1 to 8
575 p=p+s:g=g+t:i=p/45:j=g/45:if(i<1)+(i>8)+(j<1)+(j>8)goto 585
580 l=8*i+j+62:w=8*u+v-9:r=@(w)/abs(@(w)):print #1,i,j," ",:goto 585+5*@(l)
585 next m:print "...missed":goto 65
590 s=rnd(99)+280:for m=135 to 140:if(@(m+6)=i)*(@(m+12)=j)gosub 305
592 next m:goto 65
595 b=b-1:@(l)=0:@(w)=@(w)-10*r:print "Starbase destroyed"
597 print "Spock: 'I often find human behaviour fascinating.'":goto 65
600 print "Hit a star":if rnd(9)<3 print "Torpedo absorbed":goto 65
605 @(l)=0:@(w)=@(w)-r:if rnd(9)<6 print "Star destroyed":goto 65
610 t=300:print "It novas ***radiation alarm***":gosub 360:goto 65
615 input "course (0-360):",i:if(i>360)+(i<0)r=0:return
620 s=(i+45)/90:i=i-s*90:r=(45+i*i)/110+45:goto 625+5*(s<4)*s
625 s=-45:t=i:return
630 s=i:t=45:return
635 s=45:t=-i:return
640 s=-i:t=-45:return
Put the above in a file, trek.bas, and run: dds7 trek.bas.
Or, load dds, and type: old trek.bas
------------------------------------------------------------------------*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <time.h>
enum {false, true};
typedef char* CHARP;
int *gosub_stackp,gosub_stack[999],line[999],line_off[999], lim[999],var[999];
int *gosub_foop, gosub_foo[999], at[999];
int tracing;
CHARP m[12*999], pos; // pos used as expr ptr
int myrandom(int range) {
return rand() % range + 1;
}
int findop(char op) {
switch (op) {
case '=': return 1;
case '#': return 1; // <>, not equal
case '<': return 2;
case '>': return 2;
case '$': return 2; // <=
case '!': return 2; // >=
case '+': return 3;
case '-': return 3;
case '*': return 4;
case '/': return 4;
case '%': return 4;
}
return -1;
}
int evalbinary(char op, int l1, int l2) {
switch (op) {
case '=': return l1 == l2;
case '#': return l1 != l2; // <>, not equal
case '<': return l1 < l2;
case '>': return l1 > l2;
case '$': return l1 <= l2; // <=
case '!': return l1 >= l2; // >=
case '+': return l1 + l2;
case '-': return l1 - l2;
case '*': return l1 * l2;
case '/': return l1 / l2;
case '%': return l1 % l2;
}
return 0;
}
int expr(int prec) {
int o, this_prec, idx;
if (*pos=='-') {
pos++;
o = -expr(999);
} else if (isdigit(*pos)) {
o = strtol(pos,&pos,10); // can't use 0 for base, because of hex pbm.
} else if (*pos=='(') {
++pos;
o = expr(0);
++pos;
} else if (*pos == '@') { // @(exp)
++pos;
idx = expr(999);
o = at[idx];
if (tracing) printf("*** @(%d) = %d\n", idx, o);
} else if (memcmp(pos, "rnd", 3) == 0) { // rnd(exp)
pos += 3;
o = expr(999);
o = myrandom(o);
} else if (memcmp(pos, "abs", 3) == 0) { // abs(exp)
pos += 3;
o = abs(expr(999));
} else if (memcmp(pos, "asc", 3) == 0) { // asc("x")
pos += 5;
o = *pos;
pos += 3;
} else {
o = var[*pos];
if (tracing) printf("*** %c = %d\n", *pos, o);
++pos;
}
while ((this_prec = findop(*pos)) > 0 && this_prec >= prec) {
char op = *pos++;
o = evalbinary(op, o, expr(this_prec + 1));
}
return o;
}
void print_string(void) {
int width;
++pos;
width = strchr(pos, '"') - pos;
printf("%*.*s", width, width, pos);
pos += width + 1;
}
// 'print' [[#num ',' ] expr { ',' [#num ','] expr }] [','] {':' stmt} eol
// expr can also be a literal string
void print(void) {
int print_nl;
print_nl = true;
for (;;) {
int width = 0;
if (*pos == ':' || *pos == '\0')
break;
print_nl = true;
if (*pos == '#') {
++pos;
width = expr(0);
if (*pos == ',')
++pos;
}
if (*pos == '"')
print_string();
else
printf("%*d", width, expr(0));
if (*pos == ',' || *pos == ';') {
++pos;
print_nl = false;
} else
break;
}
if (print_nl)
printf("\n");
}
void enterline(char buff[]) {
int linenum;
char *p, *s = buff;
while (*s && isspace(*s))
s++;
linenum=atoi(s);
if (m[linenum])
free(m[linenum]);
if ((p=strstr(s, " ")) != NULL)
strcpy(m[linenum]=malloc(strlen(p)),p+1);
else
m[linenum]=0;
}
void load(char fn[]) {
FILE *f;
char buff[999];
f=fopen(fn,"r");
while(fgets(buff,999,f))
(*strstr(buff,"\n")=0,enterline(buff));
fclose(f);
}
void reset_vars(void) {
int i;
for(i=0; i<999; var[i++]=0)
;
}
void guts(char *s, int *linenum0, int *offset0) {
int linenum = *linenum0, offset = *offset0;
CHARP d;
int if_cont, inquote;
char two[2];
char buff[999];
if (tracing)
printf("*** %d %s\n", linenum, s);
if (!strstr(s,"\"")) {
char *p;
while((p=strstr(s,"<>")) != 0) *p++='#',*p=' ';
while((p=strstr(s,"<=")) != 0) *p++='$',*p=' ';
while((p=strstr(s,">=")) != 0) *p++='!',*p=' ';
}
// remove extra spaces, line copied to buff
d=buff;
inquote = 0;
two[1] = '\0';
while((*two=*s) != '\0') {
if(*s=='"')
inquote++;
if(inquote&1||!strstr(" \t",two))
*d++=*s;
s++;
}
*d = 0;
s = buff;
line_processed:
pos = (s += offset);
offset = if_cont = 0;
if(s[1] == '=') { // assignment a=exp
pos=s+2;
var[*s]=expr(0);
if (tracing) printf("*** assign: %c = %d\n", *s, var[*s]);
} else if (s[0] == '@') { // assignment: @(exp)=exp
int ndx;
pos = s + 1;
ndx = expr(999); // use high prec to force end at ')'
++pos;
at[ndx] = expr(0);
if (tracing) printf("*** assign: @(%d) = %d\n", ndx, at[ndx]);
} else
switch(*s) {
case's': // stop or system
if (s[1] == 'y') // must be system
exit(0);
case'e': // end
linenum=-1;
break;
case'r': // rem and return
if (s[2]!='m') {
linenum=*--gosub_stackp; // return
offset=*--gosub_foop;
}
break;
case'i': // input [constant_string,] var and if
if (s[1]=='n') { // input
int tmp;
char in_buff[20];
d = pos = &s[5];
if (*pos == '"') {
print_string();
d = ++pos; // skip ','
}
tmp = *d;
pos = fgets(in_buff, sizeof(in_buff) - 2, stdin);
var[tmp] = isdigit(*pos) ? expr(0) : *pos;
if (tracing) printf("*** input %c = %d\n", tmp, var[tmp]);
pos = ++d;
} else { // if
pos=s+2;
if (expr(0)) {
--pos;
if_cont = true;
} else
pos = 0;
}
break;
case'p': // print string and expr
pos = &s[5];
print();
break;
case'g': // goto, gosub
pos=s+4;
if (s[2]=='s') { // gosub
*gosub_stackp++=linenum;
pos++;
}
linenum=expr(0)-1;
if (s[2] == 's') // gosub
*gosub_foop++ = (*pos == ':') ? pos - buff + 1: 0;
pos = 0;
break;
case'f': // for
{ int tmp; CHARP q;
*(q=strstr(s,"to"))=0;
pos=s+5;
var[tmp=s[3]]=expr(0);
pos=q+2;
lim[tmp]=expr(0);
line[tmp]=linenum;
line_off[tmp] = (*pos == ':') ? pos - buff + 1: 0;
break;
}
case'n': // next
d = s + 4;
pos = d + 1;
++var[*d];
if (tracing) printf("*** next %c = %d\n", *d, var[*d]);
if (var[*d]<=lim[*d]) {
linenum=line[*d];
offset=line_off[*d];
pos = 0;
}
break;
}
if (pos && *pos && (if_cont || *pos == ':')) {
s = ++pos;
goto line_processed;
}
if (!offset)
linenum++;
*linenum0 = linenum;
*offset0 = offset;
}
void run(void) {
int linenum, offset = 0;
gosub_stackp=gosub_stack;
gosub_foop=gosub_foo;
linenum=1;
reset_vars();
// set s to point to first char of line
while (linenum) {
CHARP s;
while((s=m[linenum]) == 0)
linenum++;
guts(s, &linenum, &offset);
}
}
void list(void) {
int i;
for(i=0; i<11*999; i++)
if (m[i]) printf("%d %s\n",i,m[i]);
}
void cmd_new(void) {
int i;
for(i=0; i<11*999; i++) {
if (m[i]) {
free(m[i]);
m[i]=0;
}
}
}
void cmd_save(char fn[]) {
FILE *f;
int i;
f=fopen(fn,"w");
for(i=0; i<11*999; i++)
if (m[i]) fprintf(f,"%d %s\n",i,m[i]);
fclose(f);
}
int main(int argc, char *argv[]) {
int loaded = false;
char buff[999];
time_t t;
srand((unsigned) time(&t));
m[11*999]="e";
if (argc > 1) {
load(argv[1]);
buff[0] = 'r';
loaded = true;
}
while(loaded || (puts("Ok"),gets(buff))) {
loaded = false;
switch (*buff) {
case'r': // run
run();
break;
case'l': // list
list();
break;
case'n': // new
cmd_new();
break;
case'b': // bye
return 0;
case 's': // save
cmd_save(buff + 5);
break;
case 'o': // old
load(buff + 4);
break;
case 't':
if (strcmp(buff, "trace on") == 0)
tracing = 1;
else if (strcmp(buff, "trace off") == 0)
tracing = 0;
break;
default:
if (*buff == 0 || isdigit(*buff))
enterline(buff);
else {
int ln = 0, off = 0;
guts(buff, &ln, &off);
}
}
}
return 0;
}
