C ++ Lua 5.1问题

Question

#include <stdio.h>
#include <string.h>
#include <lua.h>
#include <lauxlib.h>
#include <lualib.h>

    int main (void) {
      char buff[256];
      int error;
      lua_State *L = lua_open();   /* opens Lua */
      luaL_openlibs(L);

      while (fgets(buff, sizeof(buff), stdin) != NULL) {
        error = luaL_loadbuffer(L, buff, strlen(buff), "line") ||
                lua_pcall(L, 0, 0, 0);
        if (error) {
          fprintf(stderr, "%s", lua_tostring(L, -1));
          lua_pop(L, 1);  /* pop error message from the stack */
        }
      }

      lua_close(L);
      return 0;
    }

This seems to propagate several errors such as:

error LNK2019: unresolved external symbol "char const * __cdecl lua_tolstring(struct lua_State *,int,unsigned int *)" (?lua_tolstring@@YAPBDPAUlua_State@@HPAI@Z) referenced in function _main main.obj

What's wrong?

Answer 1

您需要将lua头文件包装在extern "C"以获取正确的符号链接以及链接到lib（如果未将其编译到项目中）

Answer 2

Lua 5.1 has lua.hpp:

// lua.hpp
// Lua header files for C++
// <<extern "C">> not supplied automatically because Lua also compiles as C++

extern "C" {
#include "lua.h"
#include "lualib.h"
#include "lauxlib.h"
}

Just #include <lua.hpp> .

Answer 3

Encountered this linking error and I Had to change the

#define LUA_API extern

to

#define LUA_API extern "C"

I'm using Lua 5.1 BTW

Answer 4

Probably nothing wrong with your code, you have a linking problem, it can't find the function definition for lua_tolstring. Add the lua library when linking and you should be fine.

Answer 5

The Lua files are in C so you have to use

extern "C" { #include "luafiles.cpp" }

You are just getting linker errors.