收集整理的这篇文章主要介绍了Lua获取网络时间（获取时间同步服务器的时间），觉得挺不错的，现在分享给大家，也给大家做个参考。
网络授时服务是一些网络上的时间服务器提供的时间，一般用于本地时钟同步。 授时服务有很多种，一般我们选择Rfc-868。这个协议的工作流程是：（S代表Server，C代表Client）
S: 检测端口37
U: 连接到端口37
S: 以32位二进制数发送时间
U: 接收时间
U: 关闭连接
S: 关闭连接
协议非常简单，用TCP连接上后，服务器直接把时间发送回来。发送的是从1900年1月1日午夜到现在的秒数。
使用luasocket
实现的方案有很多种，Lua不一定是最简单的，选择只是出于个人兴趣。直接上代码吧
------------------------------------------------------------------------------- Network Time PRotocal-- Author: ani_di-----------------------------------------------------------------------------package.cpath = package.cpath .. ';
D:\\tools\\Lua\\5.1\\clibs\\?.dll;
?.dll'local socket = require "socket.core"server_ip = {
-- "129.6.15.29", "132.163.4.101", "132.163.4.102", "132.163.4.103", "128.138.140.44", "192.43.244.18", "131.107.1.10", "66.243.43.21", "216.200.93.8", "208.184.49.9", "207.126.98.204", "207.200.81.113", "205.188.185.33"}
function nstol(str) assert(str and #str == 4) local t = {
str:byte(1,-1)}
local n = 0 for k = 1, #t do n= n*256 + t[k] end return nend-- get time From a ip address, use tcp protoclfunction gettime(ip) print('connect ', ip) local tcp = socket.tcp() tcp:settimeout(10) tcp:connect(ip, 37) success, time = pcall(nstol, tcp:receive(4)) tcp:close() return success and time or nilendfunction nettime() for _, ip in pairs(server_ip) do time = gettime(ip) if time then return time end endend
代码原理不细说，非常简单。唯一值得一提的是socket库包含。最开始用的这句 require “socket”
在解释器中表现很好，但在用C中调用会找不到相应的module。错误提示
no field package.preload['socket'] no file '.\socket.lua' no file 'F:\Projects\Lua\nettime\lua\socket.lua' no file 'F:\Projects\Lua\nettime\lua\socket\inIT.lua' no file 'F:\Projects\Lua\nettime\socket.lua' no file 'F:\Projects\Lua\nettime\socket\init.lua' no file 'D:\tools\Lua\5.1\lua\socket.luac' no file '.\socket.dll' no file '.\socket51.dll' no file 'F:\Projects\Lua\nettime\socket.dll' no file 'F:\Projects\Lua\nettime\socket51.dll' no file 'F:\Projects\Lua\nettime\clibs\socket.dll' no file 'F:\Projects\Lua\nettime\clibs\socket51.dll' no file 'F:\Projects\Lua\nettime\loadall.dll' no file 'F:\Projects\Lua\nettime\clibs\loadall.dll'.
网上也有好多类似的提问，大抵是没仔细看作者的Guide。显著的有这么一句
The other two environment VARiables instruct the compatibility module to look for dynamic libraries and extension modules in the appropriate directories and with the appropriate filename extensions.>
LUAPATH=/?.lua; ?.lua LUACPATH=/?.dll; ?.dll
至于”socket.core”，windows默认安装位于“\socket\core.dll”。
C宿主调用
#include <
stdio.h>
#include <
string.h>
#include <
lua.h>
#include <
lauxlib.h>
#include <
lualib.h>
#include <
time.h>
#include <
Windows.h>
int load(lua_state* L, const char* func, unsigned int* utc) {
lua_getglobal(L, func);
if (lua_pcall(L, 0, 1, 0)) {
printf("Error Msg pcall %s.\n", lua_tostring(L, -1));
return -1;
}
if (!lua_isnumber(L,-1)) {
printf("time should be a number\n" );
return -2;
}
*utc = lua_tonumber(L,-1);
lua_pop(L, -1);
return 0;
}
void TimetToFileTime( time_t t, LPFILETIME pft ){
LONGLONG ll = Int32x32To64(t, 10000000) + 116444736000000000;
pft->
dwLowDateTime = (DWORD) ll;
pft->
dwHighDateTime = ll >
>
32;
}
int main(){
lua_State* L = luaL_newstate();
unsigned int utc = 0;
luaL_oPEnlibs(L);
if (luaL_loaDFile(L, "nettime.lua") || lua_pcall(L, 0, 0, 0)) {
printf("Error Msg load %s.\n", lua_tostring(L, -1));
return -1;
}
do {
if(load(L,"nettime", &
utc) == 0) {
time_t tt = utc - 2208988800L;
SysTEMTIME st;
FILETIME ft;
TimetToFileTime(tt, &
ft);
if (FileTimeToSystemTime(&
ft, &
st)) {
printf("Today is: %d-%d-%d\n", st.wYear, st.wMonth, st.wDay);
SetSystemTime(&
st);
}
break;
}
else {
puts("No network!");
Sleep(10000);
}
}
while (1);
lua_close(L);
return 0;
}