luci 打印函數封裝

轉自：https://blog.csdn.net/clirus/article/details/50499473?utm_source=blogxgwz3

最近把luci代碼深入地剖析了一遍．說實話剛開始看的時候也是雲裏霧裏,特別是dispatch函數, 這其間也是參考了幾篇文章, 特此感謝.

剛開始看luci代碼確實就和逆向沒啥區別,　需要揣摩作者對於各個變量的用途．　於是我就想了一個辦法, 就是把每個變量都打印出來.

爲此我在/usr/lib/lua/luci目錄下引入了log.lua模塊:

local M = {}
 
local tconcat = table.concat  
local tinsert = table.insert  
local srep = string.rep
 
local function local_print(str)  
    local dbg = io.open("/tmp/luci.output", "a+")
    local str = str or ""
    if dbg then
        dbg:write(str..'\n')
        dbg:close()
    end
end
 
function M.print(...)  
    local dbg = io.open("/tmp/luci.output", "a+")
    if dbg then
        dbg:write(os.date("[%H:%M:%S]: "))
        for _, o in ipairs({...}) do
            dbg:write(tostring(o)..'  ')
        end
        dbg:write("\n")
        dbg:close()
    end
end
 
function M.print_r(data, depth)  
    local depth = depth or 3
    local cstring = ""; 
    local top_flag = true
 
    local function table_len(t)
    local i = 0
    for k, v in pairs(t) do
        i = i + 1
    end
    return i
    end
 
    local function tableprint(data,cstring, local_depth)
        if data == nil then 
            local_print("core.print data is nil");
        end 
 
        local cs = cstring .. "    ";
    if top_flag then
            local_print(cstring .."{");
        top_flag = false
    end
        if(type(data)=="table") then
            for k, v in pairs(data) do
        if type(v) ~= "table" then
            if type(v) == "string" then
                        local_print(cs..tostring(k).." = ".."'"..tostring(v).."'");
            else
                        local_print(cs..tostring(k).." = "..tostring(v));
            end
        elseif table_len(v) == 0 then
            local_print(cs..tostring(k).." = ".."{}")
        elseif local_depth < depth then
                    local_print(cs..tostring(k).." = {");
                      tableprint(v,cs,local_depth+1);
        else
            local_print(cs..tostring(k).." = ".."{*}")
        end
            end 
        else
            local_print(cs..tostring(data));
        end 
        local_print(cstring .."}");
    end 
 
    tableprint(data,cstring,0);
end
 
return M  

你可以在luci目錄下任何一個地方調用

1. local log = require "luci.log"

2. log.print("Hello World")

3. log.print_r({"Hello", "World"})

另外, log模塊將輸出信息到/tmp/luci.ouput下面, 我們可以用tail命令跟蹤.

# tail -f /tmp/luci.output

於是通過這個小小的模塊, 得以一窺這個openwrt上著名的程序. 確實很有趣, 有時間我會詳細的把luci框架分析寫下來.

另外luci程序自帶了一個debug模塊, 這是一個用來分析內存佔用情況的模塊, 你也可以在dispatcher.lua模塊中開啓.它的信息記錄在/tmp/memtrace中.

參考

• Luci實現框架
• Luci tutorials
• wifidog在OpenWrt路由器上添加LuCI的模塊