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

int main(int argc, char *argv[])
{
    char buff[256];
    int error;
    lua_State *L = luaL_newstate();
    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;
}

最近学习lua脚本，编译上面程序一直如下错误 用g++ a.cpp -o a -llua -ldl

[root@localhost lua+c]# g++ a.cpp -o a -llua -ldl
a.cpp:8: 警告：不建议使用从字符串常量到‘char*’的转换
/tmp/ccij5HeF.o：在函数‘main’中：
a.cpp:(.text+0xe)：对‘luaL_newstate()’未定义的引用
a.cpp:(.text+0x24)：对‘luaL_openlibs(lua_State*)’未定义的引用
a.cpp:(.text+0x60)：对‘luaL_loadbufferx(lua_State*, char const*, unsigned int, char const*, char const*)’未定义的引用
a.cpp:(.text+0x9b)：对‘lua_pcallk(lua_State*, int, int, int, int, int (*)(lua_State*, int, int))’未定义的引用
a.cpp:(.text+0xe4)：对‘lua_tolstring(lua_State*, int, unsigned int*)’未定义的引用
a.cpp:(.text+0x107)：对‘lua_settop(lua_State*, int)’未定义的引用
a.cpp:(.text+0x140)：对‘lua_close(lua_State*)’未定义的引用

网上查的说法都是库没有链接成功，折腾了好久，最后在http://blog.csdn.NET/zuijinbuzai/article/details/7385380中找到了答案，

原来是因为lua是C语言模块，用g++调用c语言的库需要在包含头文件时加上extern "C"，就能正常编译了，即修改为

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

#include <string.h>

int main(int argc, char *argv[])
{
    char buff[256];
    int error;
    lua_State *L = luaL_newstate();
    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;
}