The C API is the set of functions that allow C code to interact with Lua. It comprises functions to read and write Lua global variables, to call Lua functions, to run pieces of Lua code, to register C functions so that they can later be called by Lua code, and so on.

Lua can call (and manipulate) functions written in Lua and functions written in C (see §3.4.10). Both are represented by the type function. The type userdata is provided to allow arbitrary C data to be stored in Lua variables. A userdata value represents a block of raw memory.

To embed Lua into your C or C++ program, you'll need the Lua headers to compile your program and a Lua library to link with it. If you're getting a ready-made Lua package for your platform, you'll probably need the development package as well. Otherwise, just download Lua and add its source directory to your project.

A C library for Lua mimics this behavior. Besides the definition of its C functions, it must also define a special function that corresponds to the main chunk of a Lua library. Once called, this function registers all C functions of the library and stores them in appropriate places.

From the point of view of C, a C function gets as its single argument the Lua state and returns (in C) an integer with the number of values it is returning (in Lua). Therefore, the function does not need to clear the stack before pushing its results.

Lua is implemented in pure ANSI C and compiles unmodified in all platforms that have an ANSI C compiler. Lua also compiles cleanly as C++. Lua is very easy to build and install.

2024年6月25日 · getstr(f->source) : "=?"; if (*s=='@' || *s=='=') s++; else if (*s==LUA_SIGNATURE[0]) s="(bstring)"; else s="(string)"; printf("\n%s <%s:%d,%d> (%d instruction%s at %p)\n", (f->linedefined==0)?"

When Lua calls a C function, it uses the same kind of stack that C uses to call Lua. The C function gets its arguments from the stack and pushes the results on the stack. To distinguish the results from other values on the stack, the function returns (in C) …

Therefore, if you have compiled Lua as C code (the most common case) and are using it in C++, you must include lua.h as follows: extern "C" { #include <lua.h> } A common trick is to create a header file lua.hpp with the above code and to include this new file in your C++ programs.

Lua 5.3 Reference Manual The reference manual is the official definition of the Lua language. For a complete introduction to Lua programming, see the book Programming in Lua.