C和Lua详解

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C和Lua详解

运行Lua脚本

    lua_State *L;   
    L = luaL_newstate();                //建立Lua运行环境
    if (L == NULL) {
        DBG_ERROR("lua cannot create state: not enough memory\n");
        return ;
    }
    luaL_openlibs(L);  
    luaopen_base(L); 
    delay_ms(3000);                                  
    luaL_dostring(L, lua_code);     //运行Lua脚本
    while(1)
        delay_ms(10000);
    lua_close(L); 

封装C语言库

linit.c

增加自定义模块rtc

static const luaL_Reg loadedlibs[] = {
  {"_G", luaopen_base},
//  {LUA_LOADLIBNAME, luaopen_package},
  {LUA_COLIBNAME, luaopen_coroutine},
  {LUA_TABLIBNAME, luaopen_table},
  {LUA_IOLIBNAME, luaopen_io}, 
  {LUA_RTCLIBNAME, luaopen_rtc}, 
//  {LUA_OSLIBNAME, luaopen_os},
  {LUA_STRLIBNAME, luaopen_string},
  {LUA_MATHLIBNAME, luaopen_math},
  {LUA_UTF8LIBNAME, luaopen_utf8}, 
//  {LUA_DBLIBNAME, luaopen_debug}, 
#if defined(LUA_COMPAT_BITLIB)
  {LUA_BITLIBNAME, luaopen_bit32},
#endif
  {NULL, NULL}
};

lualib.h

#define LUA_RTCLIBNAME  "rtc"
LUAMOD_API int (luaopen_rtc) (lua_State *L);

新建lrtclib.c

/*
** $Id: lcorolib.c,v 1.10 2016/04/11 19:19:55 roberto Exp $
** Coroutine Library
** See Copyright Notice in lua.h
*/
#define lrtclib_c
#define LUA_LIB

#include "lprefix.h"
#include "delay.h"   
#include <stdlib.h>
#include "stm32f1xx_hal.h"  
#include "rtc.h"  

#include "lua.h"

#include "lauxlib.h"
#include "lualib.h"


static int luaB_read (lua_State *L) {
    lua_pushinteger(L,calendar.timecount);
    lua_pushinteger(L,calendar.w_year);
    lua_pushinteger(L,calendar.w_month);
    lua_pushinteger(L,calendar.w_date);
    lua_pushinteger(L,calendar.hour);
    lua_pushinteger(L,calendar.min);
    lua_pushinteger(L,calendar.sec);
    return 7;
}

static int luaB_write (lua_State *L) {
    uint32_t timecout;
    if(!lua_isinteger(L,1))
    {
        lua_pushboolean(L,0);
        return 1;
    }
    timecout = lua_tointeger(L,1);
    RTC_Set4Stamp(timecout); 
    lua_pushboolean(L,1);
    return 1;
}

static const luaL_Reg rtc_funcs[] = {
  {"read", luaB_read},
  {"write", luaB_write}, 
  {NULL, NULL}
};

LUAMOD_API int luaopen_rtc (lua_State *L) {
  luaL_newlib(L, rtc_funcs);
  return 1;
}

C和Luc交互

Lua的栈，通过出栈入栈，获取参数，返回结果

判断是否传入参数

lua_isinteger(L,1);     //判断第1个参数是否是整数
lua_isnumber(L,2);      //判断第2个参数是否是浮点
lua_isboolean(L,3);     //判断第3个参数是否是布尔
lua_isstring(L,4);      //判断第4个参数是否是字符串
lua_istable(L,5);       //判断第5个参数是否是数组
lua_isfunction(L,6);    //判断第6个参数是否是函数

获取传参

lua_tointeger(L,1);     //获取第1个参数，转换成整数
lua_tonumber(L,2);      //获取第2个参数，转换成浮点
lua_toboolean(L,3);     //获取第3个参数，转换成布尔
lua_tostring(L,4);      //获取第4个参数，转换成字符串 

返回结果

lua函数可以返回多个结果

lua_pushinteger(L,1);        
lua_pushnumber(L,2.2);       
lua_pushboolean(L,0);        
lua_pushstring(L,"a");   
return 4;//函数返回结果的个数     

获取table数组

static int luaB_send (lua_State *L) {
  uint16_t number,len,i;
    uint8_t data[1024];

    if(!lua_isinteger(L,1))
        return 0; 
    if(!lua_isinteger(L,2))
        return 0; 
    if(!lua_istable(L,3))
        return 0; 
    number = lua_tointeger(L,1);
    if(number>6)
    {
        lua_pushboolean(L,0);
        return 1;
    }
    len = lua_tointeger(L,2);
    for(i=0;i<len;i++)
    {
        lua_rawgeti(L,3,i+1); 
        data[i]= lua_tonumber(L,-1);//获取数组
        lua_pop(L,1);
    }
    RS_Send_Data(number,data,len,3000);
    lua_pushboolean(L,1);
    return 1;
} 

返回数组

static int luaB_receive (lua_State *L) {
  uint16_t number,len,i;
    uint8_t data[1024];

    if(!lua_isinteger(L,1))
        return 0;  
    number = lua_tointeger(L,1);
    if(number>6)
    {
        lua_pushboolean(L,0);
        return 1;
    } 
    RS_Receive_Data(number,data,&len); 
    lua_pushinteger(L,len); 

    lua_newtable(L);//要给Lua返回table类型，先new一个，再压入栈顶
    lua_pushnumber(L,-1);   //确定数组首地址
    lua_rawseti(L,-2,0);    //
    for(i=0;i<len;i++)
    {   
        lua_pushinteger(L,data[i]);     
        lua_rawseti(L, -2, i+1); 
    }
    return 2;
}  

调用Lua函数

    lua_getglobal(L, "函数名"); 
    lua_call(L,0,0);