lotabout/write-a-C-interpreter
FreeWrite a simple interpreter of C. Inspired by c4 and largely based on it.
FreeFree tier
About lotabout/write-a-C-interpreter
Write a simple C interpreter that can interpret itself. This project is inspired by c4 and rewritten for clarity. It includes a tutorial series (English and Chinese) explaining how the interpreter is built step by step. The interpreter supports a subset of C and demonstrates that writing a compiler is not as hard as it seems.
Key Features
Self-hosting: the interpreter can interpret its own source code
Two versions: xc.c (original) and xc-tutor.c (tutorial step-by-step)
Includes a detailed tutorial series in English and Chinese
Supports running C source files with optional intermediate representation output (-s flag)
Simple design based on c4, demonstrating compiler construction fundamentals
Licensed under GPL-2.0 with 4.4k GitHub stars
Pros & Cons
Pros
- Excellent educational resource with step-by-step tutorials
- Self-hosting proves the interpreter is sufficiently complete
- Open source with permissive GPL-2.0 license
- Active community with 4.4k stars and 772 forks on GitHub
- Concise codebase that is easy to study and modify
Cons
- Implements only a subset of the C language, not full standard
- Not intended for production use; primarily educational
- Requires manual compilation with gcc before running
- Limited documentation beyond the tutorial series
Best For
Learning how compilers and interpreters are built from scratchEducational resource for understanding C language internalsTeaching tool for computer science courses on language implementationReference implementation for simple interpreter design
FAQ
What is this project?
It is a simple C interpreter that can interpret itself, inspired by c4 and rewritten for clarity.
How do I run the interpreter?
Compile xc.c with gcc (gcc -o xc xc.c) and then run it with a C source file, e.g., ./xc hello.c.
Is there documentation available?
Yes, there is a tutorial series in English under the 'tutorial' directory and a Chinese version on the author's blog.
What license is this project under?
The project is licensed under GPL-2.0.