Brainfuck interpreter written in C

brainfuck.c

#include <stdio.h>

#define match(from, to, ptr, dir, level)         \
    while(*(dir ptr)) {                          \
        if (*ptr == to && level == 0) break;     \
        if (*ptr == from) ++level;               \
        if (*ptr == to)   --level;               \
    }

char code[32768] = {0};
char data[32768] = {0};

void exec() {
    char* pc = code;
    char* p  = data;;
    int level = 0;
    int ch;
    while (*pc) {
        switch(*pc) {
            case '>': ++p;  break;
            case '<': --p;  break;
            case '+': ++*p; break;
            case '-': --*p; break;
            case '.': putchar(*p); break;
            case ',': *p = ((ch = getchar()) == EOF) ? 0 : ch; break;
            case '[': if (!*p) match('[', ']', pc, ++, level); break;
            case ']': if ( *p) match(']', '[', pc, --, level); break;
            default: break;
        }
        pc++;
    }
}

int main(int argc, const char *argv[]) {
    FILE* fp = fopen(argv[1], "r");
    char* pc = code;
    int ch;
    while ((ch=fgetc(fp)) != EOF) {
        if (ch == '>' || ch == '<' || ch == '+' || ch == '-' || 
            ch == '[' || ch == ']' || ch == '.' || ch == ',')
            *(pc++) = ch;
    }
    fclose(fp);
    exec();
    return 0;
}