1 /* Interpreter for Malbolge.                                          */
2 /* '98 Ben Olmstead.                                                  */
3 /*                                                                    */
4 /* Malbolge is the name of Dante's Eighth circle of Hell.  This       */
5 /* interpreter isn't even Copylefted; I hereby place it in the public */
6 /* domain.  Have fun...                                               */
7 /*                                                                    */
8 /* Note: in keeping with the idea that programming in Malbolge is     */
9 /* meant to be hell, there is no debugger.                            */
10 /*                                                                    */
11 /* By the way, this code assumes that short is 16 bits.  I haven't    */
12 /* seen any case where it isn't, but it might happen.  If short is    */
13 /* longer than 16 bits, it will still work, though it will take up    */
14 /* considerably more memory.                                          */
15 /*                                                                    */
16 /* If you are compiling with a 16-bit Intel compiler, you will need   */
17 /* >64K data arrays; this means using the HUGE memory model on most   */
18 /* compilers, but MS C, as of 8.00, possibly earlier as well, allows  */
19 /* you to specify a custom memory-model; the best model to choose in  */
20 /* this case is /Ashd (near code, huge data), I think.                */
21 
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <ctype.h>
25 #include <string.h>
26 
27 #ifdef __GNUC__
28 static inline
29 #endif
30 void exec( unsigned short *mem );
31 
32 #ifdef __GNUC__
33 static inline
34 #endif
35 unsigned short op( unsigned short x, unsigned short y );
36 
37 const char xlat1[] =
38   "+b(29e*j1VMEKLyC})8&m#~W>qxdRp0wkrUo[D7,XTcA\"lI"
39   ".v%{gJh4G\\-=O@5`_3i<?Z';FNQuY]szf$!BS/|t:Pn6^Ha";
40 
41 const char xlat2[] =
42   "5z]&gqtyfr$(we4{WP)H-Zn,[%\\3dL+Q;>U!pJS72FhOA1C"
43   "B6v^=I_0/8|jsb9m<.TVac`uY*MK'X~xDl}REokN:#?G\"i@";
44 
main(int argc,char ** argv)45 int main( int argc, char **argv )
46 {
47   FILE *f;
48   unsigned short i = 0, j;
49   int x;
50   unsigned short *mem;
51   if ( argc != 2 )
52   {
53     fputs( "invalid command line\n", stderr );
54     return ( 1 );
55   }
56   if ( ( f = fopen( argv[1], "r" ) ) == NULL )
57   {
58     fputs( "can't open file\n", stderr );
59     return ( 1 );
60   }
61 #ifdef _MSC_VER
62   mem = (unsigned short *)_halloc( 59049, sizeof(unsigned short) );
63 #else
64   mem = (unsigned short *)malloc( sizeof(unsigned short) * 59049 );
65 #endif
66   if ( mem == NULL )
67   {
68     fclose( f );
69     fputs( "can't allocate memory\n", stderr );
70     return ( 1 );
71   }
72   while ( ( x = getc( f ) ) != EOF )
73   {
74     if ( isspace( x ) ) continue;
75     if ( x < 127 && x > 32 )
76     {
77       if ( strchr( "ji*p</vo", xlat1[( x - 33 + i ) % 94] ) == NULL )
78       {
79         fputs( "invalid character in source file\n", stderr );
80         free( mem );
81         fclose( f );
82         return ( 1 );
83       }
84     }
85     if ( i == 59049 )
86     {
87       fputs( "input file too long\n", stderr );
88       free( mem );
89       fclose( f );
90       return ( 1 );
91     }
92     mem[i++] = x;
93   }
94   fclose( f );
95   while ( i < 59049 ) mem[i] = op( mem[i - 1], mem[i - 2] ), i++;
96   exec( mem );
97   free( mem );
98   return ( 0 );
99 }
100 
101 #ifdef __GNUC__
102 static inline
103 #endif
exec(unsigned short * mem)104 void exec( unsigned short *mem )
105 {
106   unsigned short a = 0, c = 0, d = 0;
107   int x;
108   for (;;)
109   {
110     if ( mem[c] < 33 || mem[c] > 126 ) continue;
111     switch ( xlat1[( mem[c] - 33 + c ) % 94] )
112     {
113       case 'j': d = mem[d]; break;
114       case 'i': c = mem[d]; break;
115       case '*': a = mem[d] = mem[d] / 3 + mem[d] % 3 * 19683; break;
116       case 'p': a = mem[d] = op( a, mem[d] ); break;
117       case '<':
118 #if '\n' != 10
119         if ( x == 10 ) putc( '\n', stdout ); else
120 #endif
121         putc( a, stdout );
122         break;
123       case '/':
124         x = getc( stdin );
125 #if '\n' != 10
126         if ( x == '\n' ) a = 10; else
127 #endif
128         if ( x == EOF ) a = 59048; else a = x;
129         break;
130       case 'v': return;
131     }
132     mem[c] = xlat2[mem[c] - 33];
133     if ( c == 59048 ) c = 0; else c++;
134     if ( d == 59048 ) d = 0; else d++;
135   }
136 }
137 
138 #ifdef __GNUC__
139 static inline
140 #endif
op(unsigned short x,unsigned short y)141 unsigned short op( unsigned short x, unsigned short y )
142 {
143   unsigned short i = 0, j;
144   static const unsigned short p9[5] =
145     { 1, 9, 81, 729, 6561 };
146   static const unsigned short o[9][9] =
147     {
148       { 4, 3, 3, 1, 0, 0, 1, 0, 0 },
149       { 4, 3, 5, 1, 0, 2, 1, 0, 2 },
150       { 5, 5, 4, 2, 2, 1, 2, 2, 1 },
151       { 4, 3, 3, 1, 0, 0, 7, 6, 6 },
152       { 4, 3, 5, 1, 0, 2, 7, 6, 8 },
153       { 5, 5, 4, 2, 2, 1, 8, 8, 7 },
154       { 7, 6, 6, 7, 6, 6, 4, 3, 3 },
155       { 7, 6, 8, 7, 6, 8, 4, 3, 5 },
156       { 8, 8, 7, 8, 8, 7, 5, 5, 4 },
157     };
158   for ( j = 0; j < 5; j++ )
159     i += o[y / p9[j] % 9][x / p9[j] % 9] * p9[j];
160   return ( i );
161 }
162