使用lua来读取配置文件

[小刀客]

1、在文件中include lua头文件
#include "lua.hpp"
2、在工程中设置，包含lua51.lib

3、在文件的开始处，写如下的宏
#define get_value(TYPE,L,T,S) \
lua_pushstring(L,S); \
lua_gettable(L,-2); \
T = lua_to##TYPE(L,-1);\
lua_pop(L,1)
#define get_table(name,L,T,Func) \
lua_pushstring(L,name); \
lua_gettable(L,-2); \
Func(L,T); \
lua_pop(L,1)
4、在文件的结尾处取消宏定义
#undef get_value
#undef get_table

5、假设我们读取的数据结构如下
typdef struct Pt{
double x;
double y;
double z;
}Pt;
typedef struct Mem{
int index;
char[16] name;
vector<Pt> pts;
}Mem;
typedef struct Steel{
int index;
Mem mem;
}Steel;

6、相应的输入文件input的格式为
entry{
index = 12,
mem = {
index = 10,
name = [[mem1]], --this is comment
pts = {
{
x = 12.0, -- this is comment
y = 13.0,
z = 14.0,
},
{
x = 11.0,
y = 15.0,
z = 16.0, -- this is comment
},
},

}
--[[
this is multiline
comment.
]]--
entry{
index = 13,
mem = {
index = 11,
name = [[mem2]],
pts = {
{
x = 12.0,
y = 13.0
z = 14.0,
},
{
x = 11.0,
y = 15.0,
z = 16.0,
},
{
x = 13.0,
y = 14.0,
z = 16.0,
},
},

}

7、定义读取 stell mem pt的函数
static int input_pt(lua_State* L,Pt* pt)
{
get_value("number",L,pt->x,"x");
get_value("number",L,pt->y,"y");
get_value("number",L,pt->z,"z");
return 1;
}
static int input_mem(lua_State* L,Mem* mem)
{
get_value("number",L,mem->index,"index");
char* tmp = NULL;
get_value("string",L,tmp,"name");
strcpy(mem->name,tmp); //warning maybe strlen(tmp) > 16!

// get array
lua_pushstring(L,"pts");
lua_gettable(L,-2);
int index = lua_gettop(L);
lua_pushnil(L);
while(lua_next(L,index) !=0){
Pt pt;
input_pt(L,&pt);
pts.push_back(pt);
}
lua_pop(L,1);

}
static int input_steel(lua_State* L,Steel* steel)
{
get_value("number",L,steel->index,"index");
get_table("mem",L,&steel->mem,input_mem);
}
8、读取过程
static vector<Steel> steels;
static int entry_db(lua_State* L)
{
Steel steel;
input_steel(&steel);
steels.push_back(steel);
}

static void read_input()
{
lua_State *L = lua_open(); /* opens Lua */
luaopen_base(L); /* opens the basic library */
luaopen_table(L); /* opens the table library */
luaopen_io(L); /* opens the I/O library */
luaopen_string(L); /* opens the string lib. */
luaopen_math(L); /* opens the math lib. */
lua_pushcfunction(L,&entry_gb);
lua_setglobal(L,"entry");
luaL_loadfile(L,"path/input-file-name");
lua_pcall(L,0,0,0);
lua_close(L);
}

[小刀客]

修正读取数组

// get array
lua_pushstring(L,"pts");
lua_gettable(L,-2);
int index = lua_gettop(L);
lua_pushnil(L);
while(lua_next(L,index) !=0){
Pt pt;
input_pt(L,&pt);

lua_pop(L,1);
pts.push_back(pt);

}
lua_pop(L,1);