@echo off
:: 查找形如 <input name=id value=1842 type=hidden> 的記錄中
:: 的第一個數字串
:: 通過探測每一個字符的類型來獲取，但是效率十分低下
:: code by jm 2006-10-16 CMD@XP
set num=0
setlocal enabledelayedexpansion
for /f "delims=" %%i in (input.txt) do call :intercept "%%i"
echo value=%str_%
pause
goto :eof

:intercept
set str=%1
set str=%str:~2,-2%
if not "%str%"=="" echo. "%str:~0,1%"|findstr "[0-9]">nul && (
    set num=1&set str_=!str_!%str:~0,1%&&call :intercept " !str:~1! ")||(
    if %num% equ 0 call :intercept " !str:~1! "
)
goto :eof

無奈何的方案，不依賴字符前后關系，會獲取 value= 后的任意值，速度非常快
更能處理形如input type=hidden name=id VALUE=465974855 <input type=hidden name=id value="1820988170"><input type=hidden name=id value=1008964101>
的字符串
@echo off
setlocal enabledelayedexpansion
FOR /f "delims=" %%i in (input.txt) do (
    set "t=%%i"
    set "t=!t:<= !"
    set "t=!t:>= !"
    set "t=!t:&= !"
    set "t=!t:|= !"
    call :sub !t !
)
pause
goto :eof

:sub
if "%1" == "" exit /b
if "%F%" == "1" echo %1 &set F=0
if "%1" == "value" set F=1
shift
goto sub