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kodejuice/brainfuck.c

Last active September 1, 2022 14:45
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Revisions

  1. kodejuice revised this gist Jul 30, 2018. No changes.
  2. kodejuice revised this gist Jul 30, 2018. No changes.
  3. kodejuice created this gist Aug 27, 2017.
    42 changes: 42 additions & 0 deletions brainfuck.c
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,42 @@

    char * brain_fuck(char * code, char * input){
    const int BUFSIZE = 30000;
    int * ptr = (int *) malloc(BUFSIZE * sizeof(int)),
    i_sz = strlen(input), c_sz = strlen(code),
    idx = -1, j = 0, o = 0;
    char cmd, * output = (char *) malloc(BUFSIZE);

    while (idx++ < c_sz){
    cmd = code[idx];
    if (cmd == '.' && *ptr > 0 && *ptr < 256) output[o++] = (char) *ptr;
    else if (cmd == '+') *ptr = ((*ptr | 0) + 1) % 256;
    else if (cmd == '-') *ptr = ((*ptr | 0) - 1), *ptr = *ptr == -1 ? 255 : *ptr;
    else if (cmd == '>') ptr++;
    else if (cmd == '<') ptr--;
    else if (cmd == ',' && j < i_sz) *ptr = input[j++];
    else if (cmd == '['){
    int open = 1, i = idx + 1;
    *ptr = (*ptr | 0);
    if (!*ptr){
    while (open && i++ < c_sz)
    if (code[i-1] == '[') open += 1;
    else if(code[i-1] == ']') open -= 1;
    idx = i - 1;
    }
    }
    else if (cmd == ']'){
    int open = 1, i = idx - 1;
    *ptr = (*ptr | 0);
    if (*ptr){
    while (open && i-- >= 0)
    if (code[i+1] == '[') open -= 1;
    else if (code[i+1] == ']') open += 1;
    idx = i + 1;
    }
    }
    }
    output[o] = '\0';
    return output;
    }

    brain_fuck(",[.>,]", "hello"); //=> "hello"