c89cc: A Standalone C89 Parser and Compiler

c89cc is a standalone C89 parser and compiler designed for x86-64 ELF64 systems. It provides a minimalist approach to compiling C89 code without relying on external libraries or commands, making it a lightweight and efficient tool for developers working in constrained environments.

The script is executed using a shell command, where the input C program is piped into the script, and the output is an executable file. There is an option to skip the built-in libc, which can be useful for advanced users who want to link their own libraries.

The script is structured with several modules and functions that handle different aspects of parsing and compiling. It includes core functionalities like string manipulation, input/output operations, and error handling. The script uses shell scripting techniques to manage variables, output formatting, and control flow, ensuring compatibility across different shell environments.

Key features include multi-value return and dynamic local variable helpers, a module system for managing dependencies, and a robust error reporting mechanism. The parser supports various C89 constructs, including data types, expressions, and control structures, and it uses a precedence climbing algorithm for expression evaluation.

The script is distributed under the ISC License, allowing for free use, modification, and distribution, provided the copyright notice is retained. It is designed to be 'as is,' with no warranties, emphasizing its use in experimental or educational contexts rather than production environments.