C&lua生成新配置

这篇是说c调用lua的。

会通过代码来展示如何在配置文件里面配置记录,并让c调用去执行。

有一个配置文件名称是“config”用来记录配置的

另外有个.c程序来载入config,并调用config中函数来生成新的记录。

编译：gcc -g -Wall configbylua.c -o cblua -ldl -llua -lm

下面看代码：

config

max = 3
default={name="chlaws",addr="china",url="blog.youkuaiyun.com/chlaws"}
chlaws=default
file="userinfo.txt"

function logtofile(file,user)
	out,err = io.open(file,"a+")
	if not out then return -1 end
	r={}
	r[#r+1]='entry{\n'
	for k ,v in pairs(user) do
		r[#r+1] =  k .. ':"' .. v ..'"\n'
	end
	r[#r+1]='}\n'
	s=table.concat(r)
	out:write(s)
	return 0
end

.c

/*
 * =====================================================================================
 *
 *       Filename:  configbylua.c
 *
 *    Description:  
 *
 *        Version:  1.0
 *        Created:  12/28/2012 03:30:56 PM
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  jiangwenlong (http://blog.youkuaiyun.com/chlaws), jiangwenlong@pipi.cn
 *        Company:  PIPI
 *
 * =====================================================================================
 */

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

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

#define MAX_PATH 256
char config[MAX_PATH]="./config";

void pstack(lua_State *L)
{
	int len = lua_gettop(L);
	int i = 1;
	printf("lua stack:\n");
	for(; i <= len ; ++i){
		int type = lua_type(L,i);
		switch(type){
			case LUA_TSTRING:
				printf("[%s]",lua_tostring(L,i));
				break;
			case LUA_TNUMBER:
				printf("[%d]",(int)lua_tonumber(L,i));
				break;
			case LUA_TNIL:
				printf("[nil]");
				break;
			case LUA_TBOOLEAN:
				printf("[%s]",lua_toboolean(L,i)? "true":"false");
				break;
			case LUA_TTABLE:
				printf("[table]");
				break;
			case LUA_TFUNCTION:
				printf("[func]");
				break;
			default:
				printf("[type %d]",type);
				break;
		}
		printf(" ");
	}
	printf("\n");
}

void get_luavar(lua_State *L)
{
	//取默认file值
	lua_getglobal(L,"file");
	if(!lua_isstring(L,-1)){
		luaL_error(L,"var file not type of string");
	}
	const char *lua_var_file = lua_tostring(L,-1);
	printf("lua var file:%s\n",lua_var_file);
	
	//取默认table值
	lua_getglobal(L,"default");
	if(!lua_istable(L,-1)){
		luaL_error(L,"var default not type of table");
	}
	lua_getfield(L,-1,"name");
	const char * lua_var_field = lua_tostring(L,-1);
	printf("default table field name:%s\n",lua_var_field);
	lua_pop(L,2);

	lua_getglobal(L,"default");
	lua_pushstring(L,"url");
	lua_gettable(L,-2);
	lua_var_field = lua_tostring(L,-1);
	printf("default table field url:%s\n",lua_var_field);

	//取函数压到栈顶
	lua_getglobal(L,"logtofile");
	if(!lua_isfunction(L,-1)){
		luaL_error(L,"var logtofile not type of function");
	}else{
		printf("logtofile is lua function\n");
	}
	//刷一次栈中所有元素
	pstack(L);
	//清空stack
	lua_pop(L,lua_gettop(L));
}

void set_luavar(lua_State *L)
{
	//更改file变量的值
	lua_pushstring(L,"the_user.txt");
	lua_setglobal(L,"file");
	
	//增加一个user table
	lua_newtable(L);
	
	lua_pushstring(L,"name");
	lua_pushstring(L,"jwl");
	lua_settable(L,-3);
	
	lua_pushstring(L,"addr");
	lua_pushstring(L,"hz");
	lua_settable(L,-3);
	
	lua_pushstring(L,"url");
	lua_pushstring(L,"pipi.cn");
	lua_settable(L,-3);
	
	lua_setglobal(L,"jwl");
	
	//增加一个user table
	lua_newtable(L);
	lua_pushstring(L,"mr.jiang");
	lua_setfield(L,-2,"name");
	
	lua_pushstring(L,"usa");
	lua_setfield(L,-2,"addr");
	
	lua_pushstring(L,"about.com");
	lua_setfield(L,-2,"url");
	
	lua_setglobal(L,"jiang");
	//清空stack
	lua_pop(L,lua_gettop(L));
}

void exec_luafunc(lua_State *L,const char *func,const char *file,const char *record)
{
	lua_getglobal(L,func);
	lua_getglobal(L,file);
	lua_getglobal(L,record);
	if(lua_pcall(L,2,1,0)){
		lua_error(L);
	}
	
	int ret = (int)lua_tonumber(L,-1);
	if(ret != 0){
		printf("record %s write to log failed\n",record);
	}else{
		printf("record %s write to log successful\n",record);
	}

	lua_pop(L,1);
}

int main(int argc,char**argv)
{
	if(argc == 2){
		strcpy(config,argv[1]);	
	}
	
	lua_State *L = luaL_newstate();
	luaL_openlibs(L);

	//0的时候表示都成功,否则出错
	if(luaL_loadfile(L,config) || lua_pcall(L,0,0,0)){
		lua_error(L);
	}
	
	get_luavar(L);
	set_luavar(L);
	exec_luafunc(L,"logtofile","file","chlaws");
	exec_luafunc(L,"logtofile","file","default");
	exec_luafunc(L,"logtofile","file","jwl");
	exec_luafunc(L,"logtofile","file","jiang");
	lua_close(L);
	return 0;
}

运行后会生成一个“the_user.txt",其内容如下：

entry{
addr:"usa"
name:"mr.jiang"
url:"about.com"
}
entry{
addr:"hz"
name:"jwl"
url:"pipi.cn"
}
entry{
addr:"china"
name:"chlaws"
url:"blog.youkuaiyun.com/chlaws"
}
entry{
addr:"china"
name:"chlaws"
url:"blog.youkuaiyun.com/chlaws"
}