LuaJit FFI从C函数返回字符串到Lua吗? [英] LuaJit FFI Return string from C function to Lua?

问题描述

说我有这个C函数:

__declspec(dllexport) const char* GetStr()
{
    static char buff[32]

    // Fill the buffer with some string here

    return buff;
}

这个简单的Lua模块:

And this simple Lua module:

local mymodule = {}

local ffi = require("ffi")

ffi.cdef[[
    const char* GetStr();
]]

function mymodule.get_str()
    return ffi.C.GetStr()
end

return mymodule

如何在这里从C函数获取返回的字符串作为Lua字符串:

How can I get the returned string from the C function as a Lua string here:

local mymodule = require "mymodule"

print(mymodule.get_str())

推荐答案

ffi.string 函数显然可以完成您要寻找的转换.

The ffi.string function apparently does the conversion you are looking for.

function mymodule.get_str()
    local c_str = ffi.C.GetStr()
    return ffi.string(c_str)
end

如果遇到崩溃，请确保您的C字符串以null终止，并且在您的情况下，最多包含31个字符(以免缓冲区溢出).

If you are getting a crash, then make sure that your C string is null terminated and, in your case, has at most 31 characterss (so as to not overflow its buffer).

这篇关于LuaJit FFI从C函数返回字符串到Lua吗?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！