dos脚本语法学习

• 一个dos批处理脚本，通过关键字搜索注册表并删除，坑很多，语法也很怪异，详情看注释

@echo off
::声明采用UTF-8编码，避免中文乱码问题，>NUL可以吞掉chcp输出的内容
chcp 65001 >NUL

set key_word="hello"
set recursive=1
set end_key_word=End

::now let us do it.
echo "--------------------------------------------------------------------------------------------"

call :search_del_reg_func HKEY_CLASSES_ROOT
call :search_del_reg_func HKEY_CURRENT_USER
call :search_del_reg_func HKEY_LOCAL_MACHINE
call :search_del_reg_func HKEY_USERS
call :search_del_reg_func HKEY_CURRENT_CONFIG
goto :end_print

::search and delete the regedit function
:search_del_reg_func
set search_path=%1
set reg_cmd="REG QUERY %search_path% /f %key_word% /s "
::not recursive
if %recursive%==0 (
    echo Scanning normally...   key_word:%key_word%  Root Path: %search_path%
    set reg_cmd="REG QUERY  %search_path% /f %key_word% "
)else (
    echo Scanning recursivly...  key_word:%key_word%  Root Path: %search_path%
)

FOR /F  "tokens=* " %%a IN ('%reg_cmd%') do (
    ::使用block的方式来执行，因为for里面不能使用goto，会破坏for循环结构
    call :for_func %%a %%b
    echo:
    echo:
)
goto :eof

:: for loop's block
:for_func
set item="%1"
set flags=%item:~1,3%
set flags=%flags:"=%
if "%flags%"=="%end_key_word%" (
    goto end_flags
)

if "%flags%"=="" (
    goto end_flags
)

::延迟userinput的解析，在dos里面，()里面的代码会被提前解析，如果不设置该选项的话，会导致%choice%里面的东西始终是空的
setlocal EnableDelayedExpansion

set item="%1"
set /p choice=Really delete[**%1**]? y=yes n=no:
::没有真正的or，所以用这种很挫的方式来实现
if "!choice!"=="y" goto delete_reg
if "!choice!"=="yes" goto delete_reg
if "!choice!"=="n" goto not_del_reg
if "!choice!"=="no" goto not_del_reg
goto not_del_reg

:delete_reg
reg delete %item% /f
echo WARNNING: You just deleted reg[%item%]!!!!!
goto end_flags

:not_del_reg
echo INFO: You omit this reg [%item%]!!!
goto end_flags

:end_flags
endlocal

goto :eof

:end_print
echo "-------------------------------------OVER---------------------------------------------------"