Working interpreter.

bfckr.c

@@ -0,0 +1,112 @@
+/* This program is free software. It comes without any warranty, to
+ * the extent permitted by applicable law. You can redistribute it
+ * and/or modify it under the terms of the Do What The Fuck You Want
+ * To Public License, Version 2, as published by Sam Hocevar. See
+ * http://www.wtfpl.net/ for more details. 
+ */
+
+#include<stdio.h>
+#include<stdint.h>
+#include<stdlib.h>
+#include<errno.h>
+#include<assert.h>
+#include<ctype.h>
+
+// Amount of memory on the band tape
+#define MEMORY_SIZE 10000
+
+// Memory initialized with zeros and its pointer
+uint8_t memory[MEMORY_SIZE] = {0};
+uint8_t *p = memory;
+
+// Prototypes
+void bfuck_parser(char *input);
+
+// Error handler
+void die(const char *message)
+{
+    if(errno) {
+        perror(message);
+    } else {
+        printf("[:-(] Error: %s\n", message);
+    }
+
+    exit(EXIT_FAILURE);
+}
+
+// Parses and executes a brainfuck expression
+void bfuck_parser(char *input)
+{
+    //printf("%s\n", input);
+
+    char curr;
+    uint16_t loop;
+
+    for(uint16_t i = 0; input[i] != 0; i++) {
+        curr = input[i];
+
+        switch(curr) {
+        case '>':
+            ++p;
+            break;
+
+        case '<':
+            --p;
+            break;
+
+        case '+':
+            ++*p;
+            break;
+
+        case '-':
+            --*p;
+            break;
+
+        case '.':
+            putchar(*p);
+            break;
+
+        case ',':
+            *p = getchar();
+            break;
+
+        case '[':
+            continue;
+            break;
+
+        case ']':
+            if(*p) {
+                loop = 1;
+                while(loop) {
+                    curr = input[--i];
+                    if(curr == '[') {
+                        loop--;
+                    }
+                    if(curr == ']') {
+                        loop++;
+                    }
+                }
+            }
+            break;
+
+        case ' ':
+            break;
+
+        default:
+            printf("%c", *p);
+            die("Invalid operant!");
+            break;
+        }
+    }
+}
+
+int main(int argc, char* argv[])
+{
+    if(argc < 2) {
+        die("Need more arguments.");
+    }
+
+    bfuck_parser(argv[1]);
+
+    exit(EXIT_SUCCESS);
+}