一个简单的Lua解释器

#include "stdafx.h"

#include<stdarg.h>
#include<stdlib.h>
#include<stdio.h>
#include<string.h>    
#include<math.h>

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

lua_State *L;

void errormethod(const char *fmt, ...){
	va_list argp;
	va_start(argp, fmt);
	vfprintf(stderr, fmt, argp);
	va_end(argp);
	lua_close(L);
	//exit(EXIT_FAILURE);
}

static int l_sin(lua_State* L){
	//double d = lua_tonumber(L, 1);
	double d = luaL_checknumber(L, 1);
	lua_pushnumber(L, sin(d));
	//printf("call1 %f\n", d);
	return 1;
} 

static int add(lua_State* L){
	int n1 = lua_tonumber(L, 1);
	int n2 = lua_tonumber(L, 2);
	int sum = n1 + n2;
	lua_pushnumber(L, sum);
	//printf("call2 %f\n", d);  
	return 1;
} 
  
int main(int argc, char* argv[])
{
	char buff[256];
	int error;
	L = luaL_newstate();//创建Lua环境
	luaL_openlibs(L);//加载标准库
	lua_pushcfunction(L, l_sin);
	lua_setglobal(L, "mysin");
	lua_pushcfunction(L, add);
	lua_setglobal(L, "add");
		
	while(fgets(buff, sizeof(buff), stdin) != NULL){
		error = luaL_loadbuffer(L, buff, strlen(buff), "line") || lua_pcall(L, 0, 0, 0);
		if(error){  
			//errormethod("%s\n", lua_tostring(L, -1));
			fprintf(stderr, "%s\n", lua_tostring(L, -1));
			lua_pop(L, -1);
		}
  
	}
//	lua_close(L);
	system("pause");
	return 0;
}