C API-加载文件

文件加载

c加载lua文件需要用到两个函数宏

    luaL_loadfile(lua_State* L, const char* filename)  //加载文件
    lua_pcall(lua_State *L, int nargs, int nresults, int errfunc) //执行文件

代码示例:
load_test.lua

width=200
height=300

main.cc

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

#ifdef __cplusplus
extern "C" {
#include "lua.h"
#include "lauxlib.h"
}

#endif // __cplusplus

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

void load(lua_State* L, const char* fname, int *w, int *h) {
    if (luaL_loadfile(L, fname) || lua_pcall(L, 0, 0, 0)) {
        //luaL_loadfile\lua_pcall 发生错误，两个函数都会把错误消息压入栈，并返回一个非零的错误代码，可以通过lua_tostring获得错误信息
        error(L, "error cannot run config  file:%s\n", lua_tostring(L, -1));
    }

    lua_getglobal(L, "width"); //将lua脚本中的全局变量 width 入栈
    lua_getglobal(L, "height"); 

    if (!lua_isnumber(L, -2)) {
        error(L, "error width should be a number\n");
    }
    if (!lua_isnumber(L, -1)) {
        error(L, "error height should be a number\n");
    }

    *w = lua_tointeger(L, -2);
    *h = lua_tointeger(L, -1);

}


int main() {

    lua_State* L = luaL_newstate();
    int weight = 0;
    int height = 0;
    load(L, "./load_test.lua", &weight, &height);
    printf("weight = %d, height = %d\n", weight, height);
    lua_close(L);
    system("pause");
}