util-src/windows.c
author Kim Alvefur <zash@zash.se>
Sun, 07 Jun 2020 02:25:56 +0200
changeset 10925 6eb5d2bb11af
parent 7892 b8d694646597
child 12579 1f6f05a98fcd
permissions -rw-r--r--
util-src: Use the luaL_pushfail API added in Lua 5.4 to highlight all failure conditions Actually just an alias of pushnil, but it does make it more obvious where the failure conditions are, which is good for readability.

/* Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--
*/

/*
* windows.c
* Windows support functions for Lua
*/

#include <stdio.h>
#include <windows.h>
#include <windns.h>

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

#if (LUA_VERSION_NUM == 501)
#define luaL_setfuncs(L, R, N) luaL_register(L, NULL, R)
#endif
#if (LUA_VERSION_NUM < 504)
#define luaL_pushfail lua_pushnil
#endif

static int Lget_nameservers(lua_State *L) {
	char stack_buffer[1024]; // stack allocated buffer
	IP4_ARRAY *ips = (IP4_ARRAY *) stack_buffer;
	DWORD len = sizeof(stack_buffer);
	DNS_STATUS status;

	status = DnsQueryConfig(DnsConfigDnsServerList, FALSE, NULL, NULL, ips, &len);

	if(status == 0) {
		DWORD i;
		lua_createtable(L, ips->AddrCount, 0);

		for(i = 0; i < ips->AddrCount; i++) {
			DWORD ip = ips->AddrArray[i];
			char ip_str[16] = "";
			sprintf_s(ip_str, sizeof(ip_str), "%d.%d.%d.%d", (ip >> 0) & 255, (ip >> 8) & 255, (ip >> 16) & 255, (ip >> 24) & 255);
			lua_pushstring(L, ip_str);
			lua_rawseti(L, -2, i + 1);
		}

		return 1;
	} else {
		luaL_pushfail(L);
		lua_pushfstring(L, "DnsQueryConfig returned %d", status);
		return 2;
	}
}

static int lerror(lua_State *L, char *string) {
	luaL_pushfail(L);
	lua_pushfstring(L, "%s: %d", string, GetLastError());
	return 2;
}

static int Lget_consolecolor(lua_State *L) {
	HWND console = GetStdHandle(STD_OUTPUT_HANDLE);
	WORD color;
	DWORD read_len;

	CONSOLE_SCREEN_BUFFER_INFO info;

	if(console == INVALID_HANDLE_VALUE) {
		return lerror(L, "GetStdHandle");
	}

	if(!GetConsoleScreenBufferInfo(console, &info)) {
		return lerror(L, "GetConsoleScreenBufferInfo");
	}

	if(!ReadConsoleOutputAttribute(console, &color, 1, info.dwCursorPosition, &read_len)) {
		return lerror(L, "ReadConsoleOutputAttribute");
	}

	lua_pushnumber(L, color);
	return 1;
}
static int Lset_consolecolor(lua_State *L) {
	int color = luaL_checkint(L, 1);
	HWND console = GetStdHandle(STD_OUTPUT_HANDLE);

	if(console == INVALID_HANDLE_VALUE) {
		return lerror(L, "GetStdHandle");
	}

	if(!SetConsoleTextAttribute(console, color)) {
		return lerror(L, "SetConsoleTextAttribute");
	}

	lua_pushboolean(L, 1);
	return 1;
}

static const luaL_Reg Reg[] = {
	{ "get_nameservers",	Lget_nameservers	},
	{ "get_consolecolor",	Lget_consolecolor	},
	{ "set_consolecolor",	Lset_consolecolor	},
	{ NULL,		NULL	}
};

LUALIB_API int luaopen_util_windows(lua_State *L) {
#if (LUA_VERSION_NUM > 501)
	luaL_checkversion(L);
#endif
	lua_newtable(L);
	luaL_setfuncs(L, Reg, 0);
	lua_pushliteral(L, "-3.14");
	lua_setfield(L, -2, "version");
	return 1;
}