bf

Language: (English | 中文简体)

My programming exerise: a simple Brainfuck language (hereinafter referred to as "BF") simulator, written in ANSI C (C89).

(BF's wiki page: Wikipedia | Baidu Baike (in Chinese))

Interface

Some interfaces and some documents are modeled after repository benhoyt/inih.

Interface is as below:

typedef struct {
    bf_byte_t        *current;
    const bf_byte_t  *begin;
    const bf_byte_t  *end;  /* past-the-end */
} bf_s;

typedef struct {
    const bf_byte_t  *base_ptr;
    int               begin_offset;
    int               end_offset;  /* past-the-end */
    int               current_offset;
} bf_nearby_16_s;

int bf_init(bf_s *ths, bf_byte_t *begin, bf_byte_t *end);

int bf_nearby_16(const bf_s *ths, bf_nearby_16_s *out);

int bf_run_filename(bf_s *ths, const char *command,
    const char *filename, bf_handler_t handler, void *out_stream);

int bf_run_file(bf_s *ths, const char *command, FILE *in_file,
    bf_handler_t handler, void *out_stream);

int bf_run_memory(bf_s *ths, const char *command, const bf_byte_t *mem,
    size_t mem_size, bf_handler_t handler, void *out_stream);

int bf_run_stream(bf_s *ths, const char *command, bf_reader_t reader,
    void *in_stream, bf_handler_t handler, void *out_stream);

In short, bf_s is the class. Functions bf_run_*() and bf_nearby_16() are methods.

Funtions bf_run_*() interpret and execute BF code, which is passed as string:

• Functions bf_run_filename() and bf_run_file() get in-stream from file.
• Function bf_run_memory() get in-stream from arrays in memory.
• Function bf_run_stream() is the most general one. The first three are implemented through it.

Each time a output command . is executed, call the callback (*handler)(), with arguments: byte currently pointed to by the data pointer and out_stream.

This is the same as benhoyt/inih.

Function bf_nearby_16() used a class bf_nearby_16_s to represent result. This is for the convenience of users to format the 16 bytes near the data pointer so that they can see the memory layout.

See the comments in the function prototypes and structure typedefs in the header file for detailed documentation.

Compiling

I only kown command gcc. I don't know much about various compilating tools.

If you only compile the two files bf_test.c and bf.c together, you will get a simple interactive BF interpreter.

Also you can ignore bf_test.c, but only compile bf.c with your code, and include bf.h in your code, then you can use the types and functions in it.

History

This interpreter is a programming exercise I made myself half a year after I learned C language (which is, written in 2022-12-05). I also made a video and posted it on Bilibili (a Chinese video website) that time:

(Video) (for source code, see introduction) An overly simple Brainfuck interpreter (in Chinese)

Now (2024-12-18), I imitated benhoyt/inih and made changes to my code, and then posted it here (GitHub).

Other Information

The code style basically follows Nginx style.

Open source licence: BSD-3-Clause.