:: 句柄模拟.cmd - 模拟运算句柄操作后的句柄状态
:: qzwqzw - 2009-6-12
@echo off & setlocal EnableDelayedExpansion
if [%1]==[] (
    echo. 这是句柄操作示例, 模拟运算进行几次句柄操作后的句柄状态
    echo --------------------- call %~n0 "1>&2" "3>nul" ---------------------
    call %0 "1>&2" "3>nul" >nul
    set 句柄
    echo.
    echo --------------------- call %~n0 "1>&2" "4>file1.txt" ---------------------
    call %0 "1>&2" "4>file1.txt" >nul
    set 句柄
    echo.
    echo --------------------- call %~n0 "1>&2" "5>con" ---------------------
    call %0 "1>&2" "5>con" >nul
    set 句柄
    echo.
    pause
    goto :eof
)
set "0=con" & set "1=con" & set "2=con"
for %%h in (%句柄%) do set %%h
echo.----- 起始状态 Initiation state -----
for %%h in (0 1 2 3 4 5 6 7 8 9) do set/p=%%h=!%%h! <nul
echo.

echo.----- 预处理 Pre-process -----
:loop
if [%1]==[] goto :end
echo.----- %1 -------
set "_tmp=%~1"
set _句柄=%_tmp:~0,1%
set _句柄_2=
set _dev=
if "%_tmp:~2,1%"=="&" (set _句柄_2=%_tmp:~3%) else (set _dev=%_tmp:~2%)
for %%h in (0 1 2 3 4 5 6 7 8 9) do (
    if "!%%h!"=="" (
        set/p=b: %_句柄%[!%_句柄%!]=^>%%h[!%%h!] : <nul
        set "%%h=!%_句柄%!"
        set bak_%%h=%_句柄%
        goto :set
    )
)
:set
for %%h in (0 1 2 3 4 5 6 7 8 9) do set/p=%%h=!%%h! <nul
echo.
if defined _dev (
    set/p=a: %_dev%=^>%_句柄%[!%_句柄%!] : <nul
    set %_句柄%=%_dev%
) else if defined _句柄_2 (
    set/p=a: %_句柄_2%[!%_句柄_2%!]=^>%_句柄%[!%_句柄%!] : <nul
    set %_句柄%=!%_句柄_2%!
)
for %%h in (0 1 2 3 4 5 6 7 8 9) do set/p=%%h=!%%h! <nul
echo.
shift
goto :loop

:end
echo.----- 后处理 Post-process -----
for %%h in (0 1 2 3 4 5 6 7 8 9) do (
    if not "!bak_%%h!"=="" (
        set/p=r: !bak_%%h![]^<=%%h[!%%h!] : <nul
        set !bak_%%h!=!%%h!
        set %%h=
        set bak_%%h=
        for %%h in (0 1 2 3 4 5 6 7 8 9) do set/p=%%h=!%%h! <nul
        echo.
    )
)
set 句柄=
for %%h in (0 1 2 3 4 5 6 7 8 9) do set 句柄=!句柄! "%%h=!%%h!"
endlocal & set 句柄=%句柄%
echo.----- 结束状态 End Status -----
for %%h in (%句柄%) do set/p=%%~h <nul
echo.