在Windows上可以使用什么代替Unix管道进行进程间通信? [英] What can I use instead of a Unix pipe for inter-process communication on Windows?
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问题描述
我有一个启动子进程的应用程序.子进程从stdin读取文件以进行操作.对于某些操作，它需要一个输入文件，其中包含有关对其进行操作的文件的处理方式的信息-我们称其为控制文件".控制文件的名称也可以从stdin中读取.父应用程序可以使用临时文件作为控制文件，但我希望避免使用真正的磁盘备份文件.
I have an application that launches a subprocess. The subprocess reads files to operate on from stdin. For some operations it needs an input file containing information on what to do with the files it operates on – let's call this the "control file". The name of the control file is also read from stdin. The parent application could use a temporary file as control file, but I would prefer to avoid a real, disk-backed file.
在Linux上，这很简单:我可以创建一个Unix管道，进行分叉，在启动子进程之前关闭管道的两端，并使用/dev/fd/3 (或其他文件描述符是作为控制文件名)，然后将控制数据写入父应用程序中的管道.另外，我可以在/tmp (或其他任何内容)中使用命名管道.
On Linux, this is simple: I can create a Unix pipe, fork, close the respective ends of the pipe before starting the subprocess, and use /dev/fd/3 (or whatever the file descriptor is) as control file name, and then write the control data to the pipe in the parent application. Alternatively, I could use a named pipe in /tmp (or whatever).
如何在Windows上实现类似的目的?Windows是否可以为此使用奇怪的命名管道"，也就是说，可以通过常规C库 fread()函数读取它们吗?如果是，我使用什么文件名访问它们?还是有比使用命名管道更好的方法?
How could I achieve a similar thing on Windows? Could the strange "named pipes" Windows offers be used for this, that is, can they be read from by the usual C library fread() function? If yes, what file name do I use to access them? Or is there a better way than using named pipes?
(子过程是 exiftool 命令行实用程序以批处理模式运行，因此我无法控制它.父应用程序是用Python编写的.)
(The subprocess is the exiftool command-line utility run in batch mode, so I don't have control over it. The parent application is written in Python.)
推荐答案
您可以使用PowerShell作为批处理子进程来创建命名管道，并使用它在Windows的批处理与其他批处理/子系统之间构建IPC.
You can use PowerShell as a batch subprocess to create named pipe and use it to build IPC between the batch and others batchs / sub systems on Windows.
以下是使用该示例快速为批处理输出着色的示例: PowerShell作为通过命名管道的子进程
Here is an example using that for quickly coloring batch output : PowerShell as a subprocess through named pipe
编辑:将其设置为消息模式并使其对@Bbb更具可读性
Set it to message mode and make it more readable for @Bbb
EDIT2 :添加缺少的NOP和安全警告.
Adding missing NOP and security warning.
请注意安全性问题.对命名管道使用凭据，并注意服务器上的任何控制台/进程都可以读取fd 5.为避免这种情况，请使用真正的双向管道或其他命名管道(而不是fd 5).请勿按原样"使用此在野外.
示例批处理代码"创建双向"通过PowerShell命名管道:
Example batch "code" to create a "bi-directional" named pipe through PowerShell :
::
:: Launch a PowerShell child process in the background linked to the console and
:: earing through named pipe which name provided as an argument of this function.
::
:: Parameters :
:: [ Name] : A name for the named pipe.
:: Return :
:: 0 if the child PowerShell has been successfully launched and the named pipe is available.
:: 1 if it fails.
:: 3 if PowerShell is not present or doesn't work.
::
:LaunchPowerShellSubProcessPipe
SET LOCALV_NAME=
IF NOT "%~1" == "" SET "LOCALV_NAME=%~1"
IF "%~1" == "" ( ECHO :LaunchPowerShellSubProcessPipe need a name.& EXIT /B 1)
powershell -command "$_" 2>&1 >NUL
IF NOT "!ERRORLEVEL!" == "0" EXIT /B 3
REM As properly stated by WReach [https://mathematica.stackexchange.com/questions/198187/how-to-read-a-named-pipe-on-windows], Windows named pipe have their own hand shake logic (WaitNamedPipe... {humor}Microsoft hate us all probably{/humor}
REM To "read" the named pipe from batch in a POSIX way, we redirected reply to fd 5. Reply to the output part of the named pipe can't be read from batch directly nor with common windows tools.
REM Do not use [System.IO.Pipes.PipeOptions]::Asynchronous !
(ECHO $CloseHandle = Add-Type 'A' -PassThru -MemberDefinition '[DllImport^^^("kernel32.dll"^^^)] public static extern bool CloseHandle^^^(IntPtr hObject^^^);'; & ^
ECHO # In case of, we close the fd beforehand & ^
ECHO $Clean = $CloseHandle::CloseHandle^^^(5^^^); & ^
ECHO $npipeServer = new-object System.IO.Pipes.NamedPipeServerStream^^^('%LOCALV_NAME%', [System.IO.Pipes.PipeDirection]::In, 1, [System.IO.Pipes.PipeTransmissionMode]::Message, [System.IO.Pipes.PipeOptions]::None, 256, 256^^^); & ^
ECHO Try { & ^
ECHO $npipeServer.WaitForConnection^^^(^^^); & ^
ECHO $pipeReader = new-object System.IO.StreamReader^^^($npipeServer^^^); & ^
ECHO Try { & ^
ECHO While^^^(^^^($msg = $pipeReader.ReadLine^^^(^^^)^^^) -notmatch 'QUIT'^^^) { & ^
ECHO Try { & ^
ECHO If ^^^($msg.Length -gt 0^^^) { & ^
ECHO $disp='Server got :'+$msg; & ^
ECHO Write-Host^^^($disp^^^); & ^
ECHO $curdte = Get-Date -Format 'HH:mm:ss'; & ^
ECHO $reply='Reply to '+$msg+', im here, time is '+$curdte; & ^
ECHO $reply_flag=0; & ^
ECHO While^^^($reply_flag -eq 0^^^) { & ^
ECHO Try { & ^
ECHO Write-Output^^^($reply^^^) ^^^>5; & ^
ECHO $reply_flag=1; & ^
ECHO } Catch [System.IO.IOException] { & ^
ECHO # Deal as you whish with potential errors & ^
ECHO }; & ^
ECHO }; & ^
ECHO } & ^
ECHO } Finally { & ^
ECHO $npipeServer.Disconnect^^^(^^^); & ^
ECHO $npipeServer.WaitForConnection^^^(^^^); & ^
ECHO } & ^
ECHO }; & ^
ECHO } Catch [System.IO.IOException] { & ^
ECHO # Deal as you whish with potential errors, you will have InvalidOperation here when the streamReader is empty & ^
ECHO } & ^
ECHO } Finally { & ^
ECHO If ^^^($npipeServer^^^) { & ^
ECHO $npipeServer.Dispose^^^(^^^); & ^
ECHO } & ^
ECHO # We close the fd & ^
ECHO $Clean = $CloseHandle::CloseHandle^^^(5^^^); & ^
ECHO } & ^
ECHO exit & ^
ECHO[)| START /B powershell 2>NUL >NUL
SET /A LOCALV_TRY=20 >NUL
:LaunchPowerShellSubProcessPipe_WaitForPipe
powershell -nop -c "& {sleep -m 50}"
SET /A LOCALV_TRY=!LOCALV_TRY! - 1 >NUL
IF NOT "!LOCALV_TRY!" == "0" cmd /C "ECHO[|SET /P=|MORE 1>\\.\pipe\!LOCALV_NAME!" 2>NUL || GOTO:LaunchPowerShellSubProcessPipe_WaitForPipe
IF "!LOCALV_TRY!" == "0" EXIT /B 1
REM 250 ms. PowerShell isn't the fastest thing to start when dealing with fd redirection... And we need it fully up to write to pipe and read from fd 5.
powershell -nop -c "& {sleep -m 250}"
EXIT /B 0
以及实现示例:
@echo off
SETLOCAL ENABLEEXTENSIONS
IF ERRORLEVEL 1 (
ECHO Can't use extensions
EXIT /B 1
)
::
SETLOCAL ENABLEDELAYEDEXPANSION
IF ERRORLEVEL 1 (
ECHO Can't use expansion
EXIT /B 1
)
REM We create 'MyNamedPipe'
CALL:LaunchPowerShellSubProcessPipe "MyNamedPipe"
SET "LOCALV_RET=!ERRORLEVEL!"
IF NOT "!LOCALV_RET!" == "0" (
ECHO Failed to create the named pipe... Exit code from LaunchPowerShellSubProcessPipe : !LOCALV_RET!
EXIT /B 1
)
REM Sending something through the pipe to the PowerShell subprocess that can be used as an IPC gate for other processes
ECHO Batch send hi to the PowerShell subprocess
ECHO Hi from the batch>\\.\pipe\MyNamedPipe
REM A NOP equivalent to be sure pipe hand shake reach completion before any other comms and that nothing stay open from this CMD and the named pipe
ECHO[|SET /P=>NUL
REM At this time, the PowerShell subprocess will take few cycles to write on the console and then write the response through fd 5.
REM We can check the pipe availability in the same way it's done in :LaunchPowerShellSubProcessPipe, but a direct read will suffice here.
REM If we've read from the pipe, it should have ben a blocked read as we've created a synchronous pipe.
REM As we read reply from fd 5, it's not synchronous, so we need to wait until we get the reply.
:WaitForReply
SET LOCALV_REPLY=0
FOR /F "tokens=*" %%R IN ('MORE ^<5') DO (
ECHO Batch got a reply from SubProcess : %%R
SET LOCALV_REPLY=1
)
IF NOT "!LOCALV_REPLY!" == "1" GOTO :WaitForReply
ECHO caller is happy >\\.\pipe\MyNamedPipe
REM A NOP equivalent to be sure pipe hand shake reach completion before any other comms and that nothing stay open from this CMD and the named pipe
ECHO[|SET /P=>NUL
:WaitForReply2
SET LOCALV_REPLY=0
FOR /F "tokens=*" %%R IN ('MORE ^<5') DO (
ECHO Batch got a 2nd reply from SubProcess : %%R
SET LOCALV_REPLY=1
)
IF NOT "!LOCALV_REPLY!" == "1" GOTO :WaitForReply2
REM Waiting one second for visible time delta
powershell -nop -c "& {sleep -m 1000}"
ECHO This is my leave. >\\.\pipe\MyNamedPipe
REM A NOP equivalent to be sure pipe hand shake reach completion before any other comms and that nothing stay open from this CMD and the named pipe
ECHO[|SET /P=>NUL
:WaitForReply3
SET LOCALV_REPLY=0
FOR /F "tokens=*" %%R IN ('MORE ^<5') DO (
ECHO Batch got a 3th reply from SubProcess : %%R
SET LOCALV_REPLY=1
)
IF NOT "!LOCALV_REPLY!" == "1" GOTO :WaitForReply3
REM We can now tell goodbye to the PowerShell subprocess
ECHO QUIT>\\.\pipe\MyNamedPipe
EXIT /B 0
::
:: Launch a PowerShell child process in the background linked to the console and
:: earing through named pipe which name provided as an argument of this function.
::
:: Parameters :
:: [ Name] : A name for the named pipe.
:: Return :
:: 0 if the child PowerShell has been successfully launched and the named pipe is available.
:: 1 if it fails.
:: 3 if PowerShell is not present or doesn't work.
::
:LaunchPowerShellSubProcessPipe
SET LOCALV_NAME=
IF NOT "%~1" == "" SET "LOCALV_NAME=%~1"
IF "%~1" == "" ( ECHO :LaunchPowerShellSubProcessPipe need a name.& EXIT /B 1)
powershell -command "$_" 2>&1 >NUL
IF NOT "!ERRORLEVEL!" == "0" EXIT /B 3
REM As properly stated by WReach [https://mathematica.stackexchange.com/questions/198187/how-to-read-a-named-pipe-on-windows], Windows named pipe have their own hand shake logic (WaitNamedPipe... {humor}Microsoft hate us all probably{/humor}
REM To "read" the named pipe from batch in a POSIX way, we redirected reply to fd 5. Reply to the output part of the named pipe can't be read from batch directly nor with common windows tools.
REM Do not use [System.IO.Pipes.PipeOptions]::Asynchronous !
(ECHO $CloseHandle = Add-Type 'A' -PassThru -MemberDefinition '[DllImport^^^("kernel32.dll"^^^)] public static extern bool CloseHandle^^^(IntPtr hObject^^^);'; & ^
ECHO # In case of, we close the fd beforehand & ^
ECHO $Clean = $CloseHandle::CloseHandle^^^(5^^^); & ^
ECHO $npipeServer = new-object System.IO.Pipes.NamedPipeServerStream^^^('%LOCALV_NAME%', [System.IO.Pipes.PipeDirection]::In, 1, [System.IO.Pipes.PipeTransmissionMode]::Message, [System.IO.Pipes.PipeOptions]::None, 256, 256^^^); & ^
ECHO Try { & ^
ECHO $npipeServer.WaitForConnection^^^(^^^); & ^
ECHO $pipeReader = new-object System.IO.StreamReader^^^($npipeServer^^^); & ^
ECHO Try { & ^
ECHO While^^^(^^^($msg = $pipeReader.ReadLine^^^(^^^)^^^) -notmatch 'QUIT'^^^) { & ^
ECHO Try { & ^
ECHO If ^^^($msg.Length -gt 0^^^) { & ^
ECHO $disp='Server got :'+$msg; & ^
ECHO Write-Host^^^($disp^^^); & ^
ECHO $curdte = Get-Date -Format 'HH:mm:ss'; & ^
ECHO $reply='Reply to '+$msg+', im here, time is '+$curdte; & ^
ECHO $reply_flag=0; & ^
ECHO While^^^($reply_flag -eq 0^^^) { & ^
ECHO Try { & ^
ECHO Write-Output^^^($reply^^^) ^^^>5; & ^
ECHO $reply_flag=1; & ^
ECHO } Catch [System.IO.IOException] { & ^
ECHO # Deal as you whish with potential errors & ^
ECHO }; & ^
ECHO }; & ^
ECHO } & ^
ECHO } Finally { & ^
ECHO $npipeServer.Disconnect^^^(^^^); & ^
ECHO $npipeServer.WaitForConnection^^^(^^^); & ^
ECHO } & ^
ECHO }; & ^
ECHO } Catch [System.IO.IOException] { & ^
ECHO # Deal as you whish with potential errors, you will have InvalidOperation here when the streamReader is empty & ^
ECHO } & ^
ECHO } Finally { & ^
ECHO If ^^^($npipeServer^^^) { & ^
ECHO $npipeServer.Dispose^^^(^^^); & ^
ECHO } & ^
ECHO # We close the fd & ^
ECHO $Clean = $CloseHandle::CloseHandle^^^(5^^^); & ^
ECHO } & ^
ECHO exit & ^
ECHO[)| START /B powershell 2>NUL >NUL
SET /A LOCALV_TRY=20 >NUL
:LaunchPowerShellSubProcessPipe_WaitForPipe
powershell -nop -c "& {sleep -m 50}"
SET /A LOCALV_TRY=!LOCALV_TRY! - 1 >NUL
IF NOT "!LOCALV_TRY!" == "0" cmd /C "ECHO[|SET /P=|MORE 1>\\.\pipe\!LOCALV_NAME!" 2>NUL || GOTO:LaunchPowerShellSubProcessPipe_WaitForPipe
IF "!LOCALV_TRY!" == "0" EXIT /B 1
REM 250 ms. PowerShell isn't the fastest thing to start when dealing with fd redirection... And we need it fully up to write to pipe and read from fd 5.
powershell -nop -c "& {sleep -m 250}"
EXIT /B 0
预期输出:
Batch send hi to the PowerShell subprocess
Batch got a reply from SubProcess : Reply to Hi from the batch, im here, time is 14:15:34
Batch got a 2nd reply from SubProcess : Reply to caller is happy , im here, time is 14:15:34
Batch got a 3th reply from SubProcess : Reply to This is my leave. , im here, time is 14:15:35
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