PowerShell 管道添加换行符
PowerShell's pipe adds linefeed
我正在尝试将一个字符串通过管道传输到程序的 STDIN ，而没有 任何尾随换行符（除非该字符串本身实际上以换行符结尾）。我试着用谷歌搜索，但我只发现有人试图在没有尾随换行符的情况下打印到 控制台 ，在这种情况下 Write-Host 需要一个参数 -NoNewLine。但是，要将其通过管道传输到另一个程序，我需要 Write-Output 或没有此类参数的类似程序。现在看来 Write-Output 甚至都不是问题：
Z:\> (Write-Output "abc").Length
3
但是，一旦我将它通过管道传输到另一个程序并在那里读取字符串，我就会得到一个额外的换行符。例如，我试过这个 Ruby 片段：
Z:\> Write-Output "abc" | ruby -e "p ARGF.read"
"abc\n"
我检查过实际收到的字符串是abc\n。同样的情况也发生在其他几种语言中（至少是 C#、Java 和 Python），所以我认为这是 PowerShell 的问题，而不是执行读取的语言。
作为进一步的测试，我用另一个 Ruby 脚本替换了 Write-Output 本身：
Z:\> ruby -e "$> << 'abc'"
abcZ:\>
（也就是说，脚本的 STDOUT 上肯定没有 \n。）
但是，当我将它通过管道传输到另一个脚本时：
Z:\> ruby -e "$> << 'abc'" | ruby -e "p ARGF.read"
"abc\n"
我相当确信是管道添加了换行符。我该如何避免这种情况？我实际上希望能够控制输入是否以换行结束（通过将其包含在输入中或省略它）。
（作为参考，我还测试了已经包含尾随换行符的字符串，在这种情况下，管道 不会 添加另一个，所以我想它只是确保了尾随换行。)
我最初是在 PowerShell v3 中遇到这个问题，但我现在使用 v5 时仍然遇到同样的问题。
暴力破解方法：将二进制数据提供给进程的标准输入。我已经在 UnixUtils 的 cat.exe 上测试了这段代码，它似乎可以满足您的要求：
# Text to send
$InputVar = "No Newline, No NewLine,`nNewLine, No NewLine,`nNewLine, No NewLine"
# Buffer & initial size of MemoryStream
$BufferSize = 4096
# Convert text to bytes and write to MemoryStream
[byte[]]$InputBytes = [Text.Encoding]::UTF8.GetBytes($InputVar)
$MemStream = New-Object -TypeName System.IO.MemoryStream -ArgumentList $BufferSize
$MemStream.Write($InputBytes, 0, $InputBytes.Length)
[Void]$MemStream.Seek(0, 'Begin')
# Setup stdin\stdout redirection for our process
$StartInfo = New-Object -TypeName System.Diagnostics.ProcessStartInfo -Property @{
FileName = 'MyLittle.exe'
UseShellExecute = $false
RedirectStandardInput = $true
}
# Create new process
$Process = New-Object -TypeName System.Diagnostics.Process
# Assign previously created StartInfo properties
$Process.StartInfo = $StartInfo
# Start process
[void]$Process.Start()
# Pipe data
$Buffer = New-Object -TypeName byte[] -ArgumentList $BufferSize
$StdinStream = $Process.StandardInput.BaseStream
try
{
do
{
$ReadCount = $MemStream.Read($Buffer, 0, $Buffer.Length)
$StdinStream.Write($Buffer, 0, $ReadCount)
$StdinStream.Flush()
}
while($ReadCount -gt 0)
}
catch
{
throw 'Houston, we have a problem!'
}
finally
{
# Close streams
$StdinStream.Close()
$MemStream.Close()
}
# Cleanup
'Process', 'StdinStream', 'MemStream' |
ForEach-Object {
(Get-Variable $_ -ValueOnly).Dispose()
Remove-Variable $_ -Force
}
简介
这是我的 Invoke-RawPipeline 函数（从 this Gist) 获取最新版本。
使用它在进程的标准输出和标准输入流之间传输二进制数据。它可以从 file/pipeline 读取输入流并将结果输出流保存到文件。
它需要 PsAsync module 才能在多个进程中启动和传输数据。
如果出现问题，请使用 -Verbose 开关查看调试输出。
例子
正在重定向到文件
- 批次：
findstr.exe /C:"Warning" /I C:\Windows\WindowsUpdate.log > C:\WU_Warnings.txt
- PowerShell:
Invoke-RawPipeline -Command @{Path = 'findstr.exe' ; Arguments = '/C:"Warning" /I C:\Windows\WindowsUpdate.log'} -OutFile 'C:\WU_Warnings.txt'
从文件重定向
- 批次：
svnadmin load < C:\RepoDumps\MyRepo.dump
- PowerShell:
Invoke-RawPipeline -InFile 'C:\RepoDumps\MyRepo.dump' -Command @{Path = 'svnadmin.exe' ; Arguments = 'load'}
管弦
- 批次：
echo TestString | find /I "test" > C:\SearchResult.log
- PowerShell:
'TestString' | Invoke-RawPipeline -Command @{Path = 'find.exe' ; Arguments = '/I "test"'} -OutFile 'C:\SearchResult.log'
多个进程之间的管道
- 批次：
ipconfig | findstr /C:"IPv4 Address" /I
- PowerShell:
Invoke-RawPipeline -Command @{Path = 'ipconfig'}, @{Path = 'findstr' ; Arguments = '/C:"IPv4 Address" /I'} -RawData
代码：
<#
.Synopsis
Pipe binary data between processes' Standard Output and Standard Input streams.
Can read input stream from file and save resulting output stream to file.
.Description
Pipe binary data between processes' Standard Output and Standard Input streams.
Can read input stream from file/pipeline and save resulting output stream to file.
Requires PsAsync module: http://psasync.codeplex.com
.Notes
Author: beatcracker (https://beatcracker.wordpress.com, https://github.com/beatcracker)
License: Microsoft Public License (http://opensource.org/licenses/MS-PL)
.Component
Requires PsAsync module: http://psasync.codeplex.com
.Parameter Command
An array of hashtables, each containing Command Name, Working Directory and Arguments
.Parameter InFile
This parameter is optional.
A string representing path to file, to read input stream from.
.Parameter OutFile
This parameter is optional.
A string representing path to file, to save resulting output stream to.
.Parameter Append
This parameter is optional. Default is false.
A switch controlling wheither ovewrite or append output file if it already exists. Default is to overwrite.
.Parameter IoTimeout
This parameter is optional. Default is 0.
A number of seconds to wait if Input/Output streams are blocked. Default is to wait indefinetely.
.Parameter ProcessTimeout
This parameter is optional. Default is 0.
A number of seconds to wait for process to exit after finishing all pipeline operations. Default is to wait indefinetely.
Details: https://msdn.microsoft.com/en-us/library/ty0d8k56.aspx
.Parameter BufferSize
This parameter is optional. Default is 4096.
Size of buffer in bytes for read\write operations. Supports standard Powershell multipliers: KB, MB, GB, TB, and PB.
Total number of buffers is: Command.Count * 2 + InFile + OutFile.
.Parameter ForceGC
This parameter is optional.
A switch, that if specified will force .Net garbage collection.
Use to immediately release memory on function exit, if large buffer size was used.
.Parameter RawData
This parameter is optional.
By default function returns object with StdOut/StdErr streams and process' exit codes.
If this switch is specified, function will return raw Standard Output stream.
.Example
Invoke-RawPipeline -Command @{Path = 'findstr.exe' ; Arguments = '/C:"Warning" /I C:\Windows\WindowsUpdate.log'} -OutFile 'C:\WU_Warnings.txt'
Batch analog: findstr.exe /C:"Warning" /I C:\Windows\WindowsUpdate.log' > C:\WU_Warnings.txt
.Example
Invoke-RawPipeline -Command @{Path = 'findstr.exe' ; WorkingDirectory = 'C:\Windows' ; Arguments = '/C:"Warning" /I .\WindowsUpdate.log'} -RawData
Batch analog: cd /D C:\Windows && findstr.exe /C:"Warning" /I .\WindowsUpdate.log
.Example
'TestString' | Invoke-RawPipeline -Command @{Path = 'find.exe' ; Arguments = '/I "test"'} -OutFile 'C:\SearchResult.log'
Batch analog: echo TestString | find /I "test" > C:\SearchResult.log
.Example
Invoke-RawPipeline -Command @{Path = 'ipconfig'}, @{Path = 'findstr' ; Arguments = '/C:"IPv4 Address" /I'} -RawData
Batch analog: ipconfig | findstr /C:"IPv4 Address" /I
.Example
Invoke-RawPipeline -InFile 'C:\RepoDumps\Repo.svn' -Command @{Path = 'svnadmin.exe' ; Arguments = 'load'}
Batch analog: svnadmin load < C:\RepoDumps\MyRepo.dump
#>
function Invoke-RawPipeline
{
[CmdletBinding()]
Param
(
[Parameter(ValueFromPipeline = $true)]
[ValidateNotNullOrEmpty()]
[ValidateScript({
if($_.psobject.Methods.Match.('ToString'))
{
$true
}
else
{
throw 'Can''t convert pipeline object to string!'
}
})]
$InVariable,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[ValidateScript({
$_ | ForEach-Object {
$Path = $_.Path
$WorkingDirectory = $_.WorkingDirectory
if(!(Get-Command -Name $Path -CommandType Application -ErrorAction SilentlyContinue))
{
throw "Command not found: $Path"
}
if($WorkingDirectory)
{
if(!(Test-Path -LiteralPath $WorkingDirectory -PathType Container -ErrorAction SilentlyContinue))
{
throw "Working directory not found: $WorkingDirectory"
}
}
}
$true
})]
[ValidateNotNullOrEmpty()]
[array]$Command,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[ValidateScript({
if(!(Test-Path -LiteralPath $_))
{
throw "File not found: $_"
}
$true
})]
[ValidateNotNullOrEmpty()]
[string]$InFile,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[ValidateScript({
if(!(Test-Path -LiteralPath (Split-Path $_)))
{
throw "Folder not found: $_"
}
$true
})]
[ValidateNotNullOrEmpty()]
[string]$OutFile,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[switch]$Append,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[ValidateRange(0, 2147483)]
[int]$IoTimeout = 0,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[ValidateRange(0, 2147483)]
[int]$ProcessTimeout = 0,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[long]$BufferSize = 4096,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[switch]$RawData,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[switch]$ForceGC
)
Begin
{
$Modules = @{PsAsync = 'http://psasync.codeplex.com'}
'Loading modules:', ($Modules | Format-Table -HideTableHeaders -AutoSize | Out-String) | Write-Verbose
foreach($module in $Modules.GetEnumerator())
{
if(!(Get-Module -Name $module.Key))
{
Try
{
Import-Module -Name $module.Key -ErrorAction Stop
}
Catch
{
throw "$($module.Key) module not available. Get it here: $($module.Value)"
}
}
}
function New-ConsoleProcess
{
Param
(
[string]$Path,
[string]$Arguments,
[string]$WorkingDirectory,
[switch]$CreateNoWindow = $true,
[switch]$RedirectStdIn = $true,
[switch]$RedirectStdOut = $true,
[switch]$RedirectStdErr = $true
)
if(!$WorkingDirectory)
{
if(!$script:MyInvocation.MyCommand.Path)
{
$WorkingDirectory = [System.AppDomain]::CurrentDomain.BaseDirectory
}
else
{
$WorkingDirectory = Split-Path $script:MyInvocation.MyCommand.Path
}
}
Try
{
$ps = New-Object -TypeName System.Diagnostics.Process -ErrorAction Stop
$ps.StartInfo.Filename = $Path
$ps.StartInfo.Arguments = $Arguments
$ps.StartInfo.UseShellExecute = $false
$ps.StartInfo.RedirectStandardInput = $RedirectStdIn
$ps.StartInfo.RedirectStandardOutput = $RedirectStdOut
$ps.StartInfo.RedirectStandardError = $RedirectStdErr
$ps.StartInfo.CreateNoWindow = $CreateNoWindow
$ps.StartInfo.WorkingDirectory = $WorkingDirectory
}
Catch
{
throw $_
}
return $ps
}
function Invoke-GarbageCollection
{
[gc]::Collect()
[gc]::WaitForPendingFinalizers()
}
$CleanUp = {
$IoWorkers + $StdErrWorkers |
ForEach-Object {
$_.Src, $_.Dst |
ForEach-Object {
if(!($_ -is [System.Diagnostics.Process]))
{
Try
{
$_.Close()
}
Catch
{
Write-Error "Failed to close $_"
}
$_.Dispose()
}
}
}
}
$PumpData = {
Param
(
[hashtable]$Cfg
)
# Fail hard, we don't want stuck threads
$Private:ErrorActionPreference = 'Stop'
$Src = $Cfg.Src
$SrcEndpoint = $Cfg.SrcEndpoint
$Dst = $Cfg.Dst
$DstEndpoint = $Cfg.DstEndpoint
$BufferSize = $Cfg.BufferSize
$SyncHash = $Cfg.SyncHash
$RunspaceId = $Cfg.Id
# Setup Input and Output streams
if($Src -is [System.Diagnostics.Process])
{
switch ($SrcEndpoint)
{
'StdOut' {$InStream = $Src.StandardOutput.BaseStream}
'StdIn' {$InStream = $Src.StandardInput.BaseStream}
'StdErr' {$InStream = $Src.StandardError.BaseStream}
default {throw "Not valid source endpoint: $_"}
}
}
else
{
$InStream = $Src
}
if($Dst -is [System.Diagnostics.Process])
{
switch ($DstEndpoint)
{
'StdOut' {$OutStream = $Dst.StandardOutput.BaseStream}
'StdIn' {$OutStream = $Dst.StandardInput.BaseStream}
'StdErr' {$OutStream = $Dst.StandardError.BaseStream}
default {throw "Not valid destination endpoint: $_"}
}
}
else
{
$OutStream = $Dst
}
$InStream | Out-String | ForEach-Object {$SyncHash.$RunspaceId.Status += "InStream: $_"}
$OutStream | Out-String | ForEach-Object {$SyncHash.$RunspaceId.Status += "OutStream: $_"}
# Main data copy loop
$Buffer = New-Object -TypeName byte[] $BufferSize
$BytesThru = 0
Try
{
Do
{
$SyncHash.$RunspaceId.IoStartTime = [DateTime]::UtcNow.Ticks
$ReadCount = $InStream.Read($Buffer, 0, $Buffer.Length)
$OutStream.Write($Buffer, 0, $ReadCount)
$OutStream.Flush()
$BytesThru += $ReadCount
}
While($readCount -gt 0)
}
Catch
{
$SyncHash.$RunspaceId.Status += $_
}
Finally
{
$OutStream.Close()
$InStream.Close()
}
}
}
Process
{
$PsCommand = @()
if($Command.Length)
{
Write-Verbose 'Creating new process objects'
$i = 0
foreach($cmd in $Command.GetEnumerator())
{
$PsCommand += New-ConsoleProcess @cmd
$i++
}
}
Write-Verbose 'Building I\O pipeline'
$PipeLine = @()
if($InVariable)
{
[Byte[]]$InVarBytes = [Text.Encoding]::UTF8.GetBytes($InVariable.ToString())
$PipeLine += New-Object -TypeName System.IO.MemoryStream -ArgumentList $BufferSize -ErrorAction Stop
$PipeLine[-1].Write($InVarBytes, 0, $InVarBytes.Length)
[Void]$PipeLine[-1].Seek(0, 'Begin')
}
elseif($InFile)
{
$PipeLine += New-Object -TypeName System.IO.FileStream -ArgumentList ($InFile, [IO.FileMode]::Open) -ErrorAction Stop
if($PsCommand.Length)
{
$PsCommand[0].StartInfo.RedirectStandardInput = $true
}
}
else
{
if($PsCommand.Length)
{
$PsCommand[0].StartInfo.RedirectStandardInput = $false
}
}
$PipeLine += $PsCommand
if($OutFile)
{
if($PsCommand.Length)
{
$PsCommand[-1].StartInfo.RedirectStandardOutput = $true
}
if($Append)
{
$FileMode = [System.IO.FileMode]::Append
}
else
{
$FileMode = [System.IO.FileMode]::Create
}
$PipeLine += New-Object -TypeName System.IO.FileStream -ArgumentList ($OutFile, $FileMode, [System.IO.FileAccess]::Write) -ErrorAction Stop
}
else
{
if($PsCommand.Length)
{
$PipeLine += New-Object -TypeName System.IO.MemoryStream -ArgumentList $BufferSize -ErrorAction Stop
}
}
Write-Verbose 'Creating I\O threads'
$IoWorkers = @()
for($i=0 ; $i -lt ($PipeLine.Length-1) ; $i++)
{
$SrcEndpoint = $DstEndpoint = $null
if($PipeLine[$i] -is [System.Diagnostics.Process])
{
$SrcEndpoint = 'StdOut'
}
if($PipeLine[$i+1] -is [System.Diagnostics.Process])
{
$DstEndpoint = 'StdIn'
}
$IoWorkers += @{
Src = $PipeLine[$i]
SrcEndpoint = $SrcEndpoint
Dst = $PipeLine[$i+1]
DstEndpoint = $DstEndpoint
}
}
Write-Verbose "Created $($IoWorkers.Length) I\O worker objects"
Write-Verbose 'Creating StdErr readers'
$StdErrWorkers = @()
for($i=0 ; $i -lt $PsCommand.Length ; $i++)
{
$StdErrWorkers += @{
Src = $PsCommand[$i]
SrcEndpoint = 'StdErr'
Dst = New-Object -TypeName System.IO.MemoryStream -ArgumentList $BufferSize -ErrorAction Stop
}
}
Write-Verbose "Created $($StdErrWorkers.Length) StdErr reader objects"
Write-Verbose 'Starting processes'
$PsCommand |
ForEach-Object {
$ps = $_
Try
{
[void]$ps.Start()
}
Catch
{
Write-Error "Failed to start process: $($ps.StartInfo.FileName)"
Write-Verbose "Can't launch process, killing and disposing all"
if($PsCommand)
{
$PsCommand |
ForEach-Object {
Try{$_.Kill()}Catch{} # Can't do much if kill fails...
$_.Dispose()
}
}
Write-Verbose 'Closing and disposing I\O streams'
. $CleanUp
}
Write-Verbose "Started new process: Name=$($ps.Name), Id=$($ps.Id)"
}
$WorkersCount = $IoWorkers.Length + $StdErrWorkers.Length
Write-Verbose 'Creating sync hashtable'
$sync = @{}
for($i=0 ; $i -lt $WorkersCount ; $i++)
{
$sync += @{$i = @{IoStartTime = $nul ; Status = $null}}
}
$SyncHash = [hashtable]::Synchronized($sync)
Write-Verbose 'Creating runspace pool'
$RunspacePool = Get-RunspacePool $WorkersCount
Write-Verbose 'Loading workers on the runspace pool'
$AsyncPipelines = @()
$i = 0
$IoWorkers + $StdErrWorkers |
ForEach-Object {
$Param = @{
BufferSize = $BufferSize
Id = $i
SyncHash = $SyncHash
} + $_
$AsyncPipelines += Invoke-Async -RunspacePool $RunspacePool -ScriptBlock $PumpData -Parameters $Param
$i++
Write-Verbose 'Started working thread'
$Param | Format-Table -HideTableHeaders -AutoSize | Out-String | Write-Debug
}
Write-Verbose 'Waiting for I\O to complete...'
if($IoTimeout){Write-Verbose "Timeout is $IoTimeout seconds"}
Do
{
# Check for pipelines with errors
[array]$FailedPipelines = Receive-AsyncStatus -Pipelines $AsyncPipelines | Where-Object {$_.Completed -and $_.Error}
if($FailedPipelines)
{
"$($FailedPipelines.Length) pipeline(s) failed!",
($FailedPipelines | Select-Object -ExpandProperty Error | Format-Table -AutoSize | Out-String) | Write-Debug
}
if($IoTimeout)
{
# Compare I\O start time of thread with current time
[array]$LockedReaders = $SyncHash.Keys | Where-Object {[TimeSpan]::FromTicks([DateTime]::UtcNow.Ticks - $SyncHash.$_.IoStartTime).TotalSeconds -gt $IoTimeout}
if($LockedReaders)
{
# Yikes, someone is stuck
"$($LockedReaders.Length) I\O operations reached timeout!" | Write-Verbose
$SyncHash.GetEnumerator() | ForEach-Object {"$($_.Key) = $($_.Value.Status)"} | Sort-Object | Out-String | Write-Debug
$PsCommand | ForEach-Object {
Write-Verbose "Killing process: Name=$($_.Name), Id=$($_.Id)"
Try
{
$_.Kill()
}
Catch
{
Write-Error 'Failed to kill process!'
}
}
break
}
}
Start-Sleep 1
}
While(Receive-AsyncStatus -Pipelines $AsyncPipelines | Where-Object {!$_.Completed}) # Loop until all pipelines are finished
Write-Verbose 'Waiting for all pipelines to finish...'
$IoStats = Receive-AsyncResults -Pipelines $AsyncPipelines
Write-Verbose 'All pipelines are finished'
Write-Verbose 'Collecting StdErr for all processes'
$PipeStdErr = $StdErrWorkers |
ForEach-Object {
$Encoding = $_.Src.StartInfo.StandardOutputEncoding
if(!$Encoding)
{
$Encoding = [System.Text.Encoding]::Default
}
@{
FileName = $_.Src.StartInfo.FileName
StdErr = $Encoding.GetString($_.Dst.ToArray())
ExitCode = $_.Src.ExitCode
}
} |
Select-Object @{Name = 'FileName' ; Expression = {$_.FileName}},
@{Name = 'StdErr' ; Expression = {$_.StdErr}},
@{Name = 'ExitCode' ; Expression = {$_.ExitCode}}
if($IoWorkers[-1].Dst -is [System.IO.MemoryStream])
{
Write-Verbose 'Collecting final pipeline output'
if($IoWorkers[-1].Src -is [System.Diagnostics.Process])
{
$Encoding = $IoWorkers[-1].Src.StartInfo.StandardOutputEncoding
}
if(!$Encoding)
{
$Encoding = [System.Text.Encoding]::Default
}
$PipeResult = $Encoding.GetString($IoWorkers[-1].Dst.ToArray())
}
Write-Verbose 'Closing and disposing I\O streams'
. $CleanUp
$PsCommand |
ForEach-Object {
$_.Refresh()
if(!$_.HasExited)
{
Write-Verbose "Process is still active: Name=$($_.Name), Id=$($_.Id)"
if(!$ProcessTimeout)
{
$ProcessTimeout = -1
}
else
{
$WaitForExitProcessTimeout = $ProcessTimeout * 1000
}
Write-Verbose "Waiting for process to exit (Process Timeout = $ProcessTimeout)"
if(!$_.WaitForExit($WaitForExitProcessTimeout))
{
Try
{
Write-Verbose 'Trying to kill it'
$_.Kill()
}
Catch
{
Write-Error "Failed to kill process $_"
}
}
}
Write-Verbose "Disposing process object: Name=$($_.StartInfo.FileName)"
$_.Dispose()
}
Write-Verbose 'Disposing runspace pool'
#
$RunspacePool.Dispose()
if($ForceGC)
{
Write-Verbose 'Forcing garbage collection'
Invoke-GarbageCollection
}
if(!$RawData)
{
New-Object -TypeName psobject -Property @{Result = $PipeResult ; Status = $PipeStdErr}
}
else
{
$PipeResult
}
}
}
我承认对您在管道后使用的 ruby -e "puts ARGF.read" 命令的经验为零，但我想我可以证明管道没有添加换行符。
# check length of string without newline after pipe
Write-Output "abc" | %{Write-Host "$_ has a length of: $($_.Length)" }
#check of string with newline length after pipe
Write-Output "def`n" | %{Write-Host "$($_.Length) is the length of $_" -NoNewline }
#write a string without newline (suppressing newline on Write-Host)
Write-Output 'abc' | %{ Write-Host $_ -NoNewline; }
#write a string with newline (suppressing newline on Write-Host)
Write-Output "def`n" | %{ Write-Host $_ -NoNewline; }
#write a final string without newline (suppressing newline on Write-Host)
Write-Output 'ghi' | %{ Write-Host $_ -NoNewline; }
这给了我一个输出：
abc has a length of: 3
4 is the length of def
abcdef
ghi
我想你可能想开始查看 ruby -e "put AGRF.read" 命令，看看它是否在每次读取后添加一个换行符。
以简单的方式创建一个 cmd 进程并执行它
$cmdArgs = @('/c','something.exe','arg1', .. , 'arg2' , $anotherArg , '<', '$somefile.txt' )
&'cmd.exe' $cmdArgs
完美地将信息通过管道传输到我想要的标准输入中，
澄清一些评论中的基本误解：管道中的“powershell 命令”是 cmdlet，每个命令都在 single[=24] 的进程 space 中运行=] 电源外壳。因此，对象在同一个进程中（在多个线程上）按原样传递 除非您调用外部命令。然后通过适当的格式化 cmdlet 将传递的对象转换为字符串（如果还不是字符串对象）。然后将这些字符串转换为字符流，每个字符串都有附加的 \n。所以它不是“管道”添加 \n 而是隐式转换为文本以输入到“旧版”命令。
问题中的基本问题是提问者试图在字符（字节）流输入上获得类似对象的行为（例如，没有尾随 \n 的字符串）。 （控制台）进程的标准输入流一次提供一个字符（字节）。输入 routines 将这些单独的字符收集到一个字符串中（通常）在收到 \n 时终止。 \n 是否被 returned 作为字符串的一部分取决于输入例程。当标准输入流被重定向到文件或管道时，输入例程大多不知道这一点。所以没有办法确定没有 \n 的完整字符串和有更多字符的不完整字符串之间的区别，并且 \n 还在后面。
可能的解决方案（针对字符串定界问题，而不是 powershell 添加的 \n 问题）是在标准输入读取上设置某种超时。字符串的结尾可以通过在一定时间内没有收到字符来表示。或者，如果您对管道的访问级别足够低，您可以尝试进行原子读写。通过这种方式，阻塞的读取将 return 正是写入的内容。不幸的是，当 运行 在多任务环境中时，这两种方法都存在计时问题。如果延迟很长，效率就会下降，但如果延迟太短，则可能会被进程优先级调度引起的延迟所愚弄。如果写入进程在读取进程读取当前行之前写入另一行，则调度优先级也会干扰原子读取和写入。它需要某种同步系统。
表示当前行没有更多字符的唯一其他方法是关闭管道 (EOF)，但这是一种一次性方法，因此您只能发送一个字符串（尾随 \n 或不是）。 （这就是 Ruby 知道初始示例和 Invoke-RawPipeline 示例中输入何时完成的方式。）这可能实际上是您的意图（只发送一个带或不带尾随 \ 的字符串n) 在这种情况下，您可以简单地连接所有输入（保留或重新插入任何嵌入的 \n）并丢弃最后一个 \n。
powershell 添加的多个字符串的 \n 问题的一个可能解决方案是重新定义“字符串”的编码，方法是使用无效的字符序列终止每个字符串对象。如果您有每个字符输入（不适合 C 类行输入），则可以使用 \0，否则可能使用 \377 (0xff)。这将允许您的遗留命令的输入例程“知道”字符串何时结束。序列 [=27=]\n（或 7\n）将是字符串的“结尾”，之前的所有内容（包括尾随 \n 或不包括，可能使用多次读取）将是字符串。我假设您对输入例程有一定的控制权（例如，您编写了程序），因为从标准输入读取的任何现成程序通常都需要 \n（或 EOF）来分隔其输入。
我正在尝试将一个字符串通过管道传输到程序的 STDIN ，而没有 任何尾随换行符（除非该字符串本身实际上以换行符结尾）。我试着用谷歌搜索，但我只发现有人试图在没有尾随换行符的情况下打印到 控制台 ，在这种情况下 Write-Host 需要一个参数 -NoNewLine。但是，要将其通过管道传输到另一个程序，我需要 Write-Output 或没有此类参数的类似程序。现在看来 Write-Output 甚至都不是问题：
Z:\> (Write-Output "abc").Length
3
但是，一旦我将它通过管道传输到另一个程序并在那里读取字符串，我就会得到一个额外的换行符。例如，我试过这个 Ruby 片段：
Z:\> Write-Output "abc" | ruby -e "p ARGF.read"
"abc\n"
我检查过实际收到的字符串是abc\n。同样的情况也发生在其他几种语言中（至少是 C#、Java 和 Python），所以我认为这是 PowerShell 的问题，而不是执行读取的语言。
作为进一步的测试，我用另一个 Ruby 脚本替换了 Write-Output 本身：
Z:\> ruby -e "$> << 'abc'"
abcZ:\>
（也就是说，脚本的 STDOUT 上肯定没有 \n。）
但是，当我将它通过管道传输到另一个脚本时：
Z:\> ruby -e "$> << 'abc'" | ruby -e "p ARGF.read"
"abc\n"
我相当确信是管道添加了换行符。我该如何避免这种情况？我实际上希望能够控制输入是否以换行结束（通过将其包含在输入中或省略它）。
（作为参考，我还测试了已经包含尾随换行符的字符串，在这种情况下，管道 不会 添加另一个，所以我想它只是确保了尾随换行。)
我最初是在 PowerShell v3 中遇到这个问题，但我现在使用 v5 时仍然遇到同样的问题。
暴力破解方法：将二进制数据提供给进程的标准输入。我已经在 UnixUtils 的 cat.exe 上测试了这段代码，它似乎可以满足您的要求：
# Text to send
$InputVar = "No Newline, No NewLine,`nNewLine, No NewLine,`nNewLine, No NewLine"
# Buffer & initial size of MemoryStream
$BufferSize = 4096
# Convert text to bytes and write to MemoryStream
[byte[]]$InputBytes = [Text.Encoding]::UTF8.GetBytes($InputVar)
$MemStream = New-Object -TypeName System.IO.MemoryStream -ArgumentList $BufferSize
$MemStream.Write($InputBytes, 0, $InputBytes.Length)
[Void]$MemStream.Seek(0, 'Begin')
# Setup stdin\stdout redirection for our process
$StartInfo = New-Object -TypeName System.Diagnostics.ProcessStartInfo -Property @{
FileName = 'MyLittle.exe'
UseShellExecute = $false
RedirectStandardInput = $true
}
# Create new process
$Process = New-Object -TypeName System.Diagnostics.Process
# Assign previously created StartInfo properties
$Process.StartInfo = $StartInfo
# Start process
[void]$Process.Start()
# Pipe data
$Buffer = New-Object -TypeName byte[] -ArgumentList $BufferSize
$StdinStream = $Process.StandardInput.BaseStream
try
{
do
{
$ReadCount = $MemStream.Read($Buffer, 0, $Buffer.Length)
$StdinStream.Write($Buffer, 0, $ReadCount)
$StdinStream.Flush()
}
while($ReadCount -gt 0)
}
catch
{
throw 'Houston, we have a problem!'
}
finally
{
# Close streams
$StdinStream.Close()
$MemStream.Close()
}
# Cleanup
'Process', 'StdinStream', 'MemStream' |
ForEach-Object {
(Get-Variable $_ -ValueOnly).Dispose()
Remove-Variable $_ -Force
}
简介
这是我的 Invoke-RawPipeline 函数（从 this Gist) 获取最新版本。
使用它在进程的标准输出和标准输入流之间传输二进制数据。它可以从 file/pipeline 读取输入流并将结果输出流保存到文件。
它需要 PsAsync module 才能在多个进程中启动和传输数据。
如果出现问题，请使用 -Verbose 开关查看调试输出。
例子
正在重定向到文件
- 批次：
findstr.exe /C:"Warning" /I C:\Windows\WindowsUpdate.log > C:\WU_Warnings.txt - PowerShell:
Invoke-RawPipeline -Command @{Path = 'findstr.exe' ; Arguments = '/C:"Warning" /I C:\Windows\WindowsUpdate.log'} -OutFile 'C:\WU_Warnings.txt'
从文件重定向
- 批次：
svnadmin load < C:\RepoDumps\MyRepo.dump - PowerShell:
Invoke-RawPipeline -InFile 'C:\RepoDumps\MyRepo.dump' -Command @{Path = 'svnadmin.exe' ; Arguments = 'load'}
管弦
- 批次：
echo TestString | find /I "test" > C:\SearchResult.log - PowerShell:
'TestString' | Invoke-RawPipeline -Command @{Path = 'find.exe' ; Arguments = '/I "test"'} -OutFile 'C:\SearchResult.log'
多个进程之间的管道
- 批次：
ipconfig | findstr /C:"IPv4 Address" /I - PowerShell:
Invoke-RawPipeline -Command @{Path = 'ipconfig'}, @{Path = 'findstr' ; Arguments = '/C:"IPv4 Address" /I'} -RawData
代码：
<#
.Synopsis
Pipe binary data between processes' Standard Output and Standard Input streams.
Can read input stream from file and save resulting output stream to file.
.Description
Pipe binary data between processes' Standard Output and Standard Input streams.
Can read input stream from file/pipeline and save resulting output stream to file.
Requires PsAsync module: http://psasync.codeplex.com
.Notes
Author: beatcracker (https://beatcracker.wordpress.com, https://github.com/beatcracker)
License: Microsoft Public License (http://opensource.org/licenses/MS-PL)
.Component
Requires PsAsync module: http://psasync.codeplex.com
.Parameter Command
An array of hashtables, each containing Command Name, Working Directory and Arguments
.Parameter InFile
This parameter is optional.
A string representing path to file, to read input stream from.
.Parameter OutFile
This parameter is optional.
A string representing path to file, to save resulting output stream to.
.Parameter Append
This parameter is optional. Default is false.
A switch controlling wheither ovewrite or append output file if it already exists. Default is to overwrite.
.Parameter IoTimeout
This parameter is optional. Default is 0.
A number of seconds to wait if Input/Output streams are blocked. Default is to wait indefinetely.
.Parameter ProcessTimeout
This parameter is optional. Default is 0.
A number of seconds to wait for process to exit after finishing all pipeline operations. Default is to wait indefinetely.
Details: https://msdn.microsoft.com/en-us/library/ty0d8k56.aspx
.Parameter BufferSize
This parameter is optional. Default is 4096.
Size of buffer in bytes for read\write operations. Supports standard Powershell multipliers: KB, MB, GB, TB, and PB.
Total number of buffers is: Command.Count * 2 + InFile + OutFile.
.Parameter ForceGC
This parameter is optional.
A switch, that if specified will force .Net garbage collection.
Use to immediately release memory on function exit, if large buffer size was used.
.Parameter RawData
This parameter is optional.
By default function returns object with StdOut/StdErr streams and process' exit codes.
If this switch is specified, function will return raw Standard Output stream.
.Example
Invoke-RawPipeline -Command @{Path = 'findstr.exe' ; Arguments = '/C:"Warning" /I C:\Windows\WindowsUpdate.log'} -OutFile 'C:\WU_Warnings.txt'
Batch analog: findstr.exe /C:"Warning" /I C:\Windows\WindowsUpdate.log' > C:\WU_Warnings.txt
.Example
Invoke-RawPipeline -Command @{Path = 'findstr.exe' ; WorkingDirectory = 'C:\Windows' ; Arguments = '/C:"Warning" /I .\WindowsUpdate.log'} -RawData
Batch analog: cd /D C:\Windows && findstr.exe /C:"Warning" /I .\WindowsUpdate.log
.Example
'TestString' | Invoke-RawPipeline -Command @{Path = 'find.exe' ; Arguments = '/I "test"'} -OutFile 'C:\SearchResult.log'
Batch analog: echo TestString | find /I "test" > C:\SearchResult.log
.Example
Invoke-RawPipeline -Command @{Path = 'ipconfig'}, @{Path = 'findstr' ; Arguments = '/C:"IPv4 Address" /I'} -RawData
Batch analog: ipconfig | findstr /C:"IPv4 Address" /I
.Example
Invoke-RawPipeline -InFile 'C:\RepoDumps\Repo.svn' -Command @{Path = 'svnadmin.exe' ; Arguments = 'load'}
Batch analog: svnadmin load < C:\RepoDumps\MyRepo.dump
#>
function Invoke-RawPipeline
{
[CmdletBinding()]
Param
(
[Parameter(ValueFromPipeline = $true)]
[ValidateNotNullOrEmpty()]
[ValidateScript({
if($_.psobject.Methods.Match.('ToString'))
{
$true
}
else
{
throw 'Can''t convert pipeline object to string!'
}
})]
$InVariable,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[ValidateScript({
$_ | ForEach-Object {
$Path = $_.Path
$WorkingDirectory = $_.WorkingDirectory
if(!(Get-Command -Name $Path -CommandType Application -ErrorAction SilentlyContinue))
{
throw "Command not found: $Path"
}
if($WorkingDirectory)
{
if(!(Test-Path -LiteralPath $WorkingDirectory -PathType Container -ErrorAction SilentlyContinue))
{
throw "Working directory not found: $WorkingDirectory"
}
}
}
$true
})]
[ValidateNotNullOrEmpty()]
[array]$Command,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[ValidateScript({
if(!(Test-Path -LiteralPath $_))
{
throw "File not found: $_"
}
$true
})]
[ValidateNotNullOrEmpty()]
[string]$InFile,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[ValidateScript({
if(!(Test-Path -LiteralPath (Split-Path $_)))
{
throw "Folder not found: $_"
}
$true
})]
[ValidateNotNullOrEmpty()]
[string]$OutFile,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[switch]$Append,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[ValidateRange(0, 2147483)]
[int]$IoTimeout = 0,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[ValidateRange(0, 2147483)]
[int]$ProcessTimeout = 0,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[long]$BufferSize = 4096,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[switch]$RawData,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[switch]$ForceGC
)
Begin
{
$Modules = @{PsAsync = 'http://psasync.codeplex.com'}
'Loading modules:', ($Modules | Format-Table -HideTableHeaders -AutoSize | Out-String) | Write-Verbose
foreach($module in $Modules.GetEnumerator())
{
if(!(Get-Module -Name $module.Key))
{
Try
{
Import-Module -Name $module.Key -ErrorAction Stop
}
Catch
{
throw "$($module.Key) module not available. Get it here: $($module.Value)"
}
}
}
function New-ConsoleProcess
{
Param
(
[string]$Path,
[string]$Arguments,
[string]$WorkingDirectory,
[switch]$CreateNoWindow = $true,
[switch]$RedirectStdIn = $true,
[switch]$RedirectStdOut = $true,
[switch]$RedirectStdErr = $true
)
if(!$WorkingDirectory)
{
if(!$script:MyInvocation.MyCommand.Path)
{
$WorkingDirectory = [System.AppDomain]::CurrentDomain.BaseDirectory
}
else
{
$WorkingDirectory = Split-Path $script:MyInvocation.MyCommand.Path
}
}
Try
{
$ps = New-Object -TypeName System.Diagnostics.Process -ErrorAction Stop
$ps.StartInfo.Filename = $Path
$ps.StartInfo.Arguments = $Arguments
$ps.StartInfo.UseShellExecute = $false
$ps.StartInfo.RedirectStandardInput = $RedirectStdIn
$ps.StartInfo.RedirectStandardOutput = $RedirectStdOut
$ps.StartInfo.RedirectStandardError = $RedirectStdErr
$ps.StartInfo.CreateNoWindow = $CreateNoWindow
$ps.StartInfo.WorkingDirectory = $WorkingDirectory
}
Catch
{
throw $_
}
return $ps
}
function Invoke-GarbageCollection
{
[gc]::Collect()
[gc]::WaitForPendingFinalizers()
}
$CleanUp = {
$IoWorkers + $StdErrWorkers |
ForEach-Object {
$_.Src, $_.Dst |
ForEach-Object {
if(!($_ -is [System.Diagnostics.Process]))
{
Try
{
$_.Close()
}
Catch
{
Write-Error "Failed to close $_"
}
$_.Dispose()
}
}
}
}
$PumpData = {
Param
(
[hashtable]$Cfg
)
# Fail hard, we don't want stuck threads
$Private:ErrorActionPreference = 'Stop'
$Src = $Cfg.Src
$SrcEndpoint = $Cfg.SrcEndpoint
$Dst = $Cfg.Dst
$DstEndpoint = $Cfg.DstEndpoint
$BufferSize = $Cfg.BufferSize
$SyncHash = $Cfg.SyncHash
$RunspaceId = $Cfg.Id
# Setup Input and Output streams
if($Src -is [System.Diagnostics.Process])
{
switch ($SrcEndpoint)
{
'StdOut' {$InStream = $Src.StandardOutput.BaseStream}
'StdIn' {$InStream = $Src.StandardInput.BaseStream}
'StdErr' {$InStream = $Src.StandardError.BaseStream}
default {throw "Not valid source endpoint: $_"}
}
}
else
{
$InStream = $Src
}
if($Dst -is [System.Diagnostics.Process])
{
switch ($DstEndpoint)
{
'StdOut' {$OutStream = $Dst.StandardOutput.BaseStream}
'StdIn' {$OutStream = $Dst.StandardInput.BaseStream}
'StdErr' {$OutStream = $Dst.StandardError.BaseStream}
default {throw "Not valid destination endpoint: $_"}
}
}
else
{
$OutStream = $Dst
}
$InStream | Out-String | ForEach-Object {$SyncHash.$RunspaceId.Status += "InStream: $_"}
$OutStream | Out-String | ForEach-Object {$SyncHash.$RunspaceId.Status += "OutStream: $_"}
# Main data copy loop
$Buffer = New-Object -TypeName byte[] $BufferSize
$BytesThru = 0
Try
{
Do
{
$SyncHash.$RunspaceId.IoStartTime = [DateTime]::UtcNow.Ticks
$ReadCount = $InStream.Read($Buffer, 0, $Buffer.Length)
$OutStream.Write($Buffer, 0, $ReadCount)
$OutStream.Flush()
$BytesThru += $ReadCount
}
While($readCount -gt 0)
}
Catch
{
$SyncHash.$RunspaceId.Status += $_
}
Finally
{
$OutStream.Close()
$InStream.Close()
}
}
}
Process
{
$PsCommand = @()
if($Command.Length)
{
Write-Verbose 'Creating new process objects'
$i = 0
foreach($cmd in $Command.GetEnumerator())
{
$PsCommand += New-ConsoleProcess @cmd
$i++
}
}
Write-Verbose 'Building I\O pipeline'
$PipeLine = @()
if($InVariable)
{
[Byte[]]$InVarBytes = [Text.Encoding]::UTF8.GetBytes($InVariable.ToString())
$PipeLine += New-Object -TypeName System.IO.MemoryStream -ArgumentList $BufferSize -ErrorAction Stop
$PipeLine[-1].Write($InVarBytes, 0, $InVarBytes.Length)
[Void]$PipeLine[-1].Seek(0, 'Begin')
}
elseif($InFile)
{
$PipeLine += New-Object -TypeName System.IO.FileStream -ArgumentList ($InFile, [IO.FileMode]::Open) -ErrorAction Stop
if($PsCommand.Length)
{
$PsCommand[0].StartInfo.RedirectStandardInput = $true
}
}
else
{
if($PsCommand.Length)
{
$PsCommand[0].StartInfo.RedirectStandardInput = $false
}
}
$PipeLine += $PsCommand
if($OutFile)
{
if($PsCommand.Length)
{
$PsCommand[-1].StartInfo.RedirectStandardOutput = $true
}
if($Append)
{
$FileMode = [System.IO.FileMode]::Append
}
else
{
$FileMode = [System.IO.FileMode]::Create
}
$PipeLine += New-Object -TypeName System.IO.FileStream -ArgumentList ($OutFile, $FileMode, [System.IO.FileAccess]::Write) -ErrorAction Stop
}
else
{
if($PsCommand.Length)
{
$PipeLine += New-Object -TypeName System.IO.MemoryStream -ArgumentList $BufferSize -ErrorAction Stop
}
}
Write-Verbose 'Creating I\O threads'
$IoWorkers = @()
for($i=0 ; $i -lt ($PipeLine.Length-1) ; $i++)
{
$SrcEndpoint = $DstEndpoint = $null
if($PipeLine[$i] -is [System.Diagnostics.Process])
{
$SrcEndpoint = 'StdOut'
}
if($PipeLine[$i+1] -is [System.Diagnostics.Process])
{
$DstEndpoint = 'StdIn'
}
$IoWorkers += @{
Src = $PipeLine[$i]
SrcEndpoint = $SrcEndpoint
Dst = $PipeLine[$i+1]
DstEndpoint = $DstEndpoint
}
}
Write-Verbose "Created $($IoWorkers.Length) I\O worker objects"
Write-Verbose 'Creating StdErr readers'
$StdErrWorkers = @()
for($i=0 ; $i -lt $PsCommand.Length ; $i++)
{
$StdErrWorkers += @{
Src = $PsCommand[$i]
SrcEndpoint = 'StdErr'
Dst = New-Object -TypeName System.IO.MemoryStream -ArgumentList $BufferSize -ErrorAction Stop
}
}
Write-Verbose "Created $($StdErrWorkers.Length) StdErr reader objects"
Write-Verbose 'Starting processes'
$PsCommand |
ForEach-Object {
$ps = $_
Try
{
[void]$ps.Start()
}
Catch
{
Write-Error "Failed to start process: $($ps.StartInfo.FileName)"
Write-Verbose "Can't launch process, killing and disposing all"
if($PsCommand)
{
$PsCommand |
ForEach-Object {
Try{$_.Kill()}Catch{} # Can't do much if kill fails...
$_.Dispose()
}
}
Write-Verbose 'Closing and disposing I\O streams'
. $CleanUp
}
Write-Verbose "Started new process: Name=$($ps.Name), Id=$($ps.Id)"
}
$WorkersCount = $IoWorkers.Length + $StdErrWorkers.Length
Write-Verbose 'Creating sync hashtable'
$sync = @{}
for($i=0 ; $i -lt $WorkersCount ; $i++)
{
$sync += @{$i = @{IoStartTime = $nul ; Status = $null}}
}
$SyncHash = [hashtable]::Synchronized($sync)
Write-Verbose 'Creating runspace pool'
$RunspacePool = Get-RunspacePool $WorkersCount
Write-Verbose 'Loading workers on the runspace pool'
$AsyncPipelines = @()
$i = 0
$IoWorkers + $StdErrWorkers |
ForEach-Object {
$Param = @{
BufferSize = $BufferSize
Id = $i
SyncHash = $SyncHash
} + $_
$AsyncPipelines += Invoke-Async -RunspacePool $RunspacePool -ScriptBlock $PumpData -Parameters $Param
$i++
Write-Verbose 'Started working thread'
$Param | Format-Table -HideTableHeaders -AutoSize | Out-String | Write-Debug
}
Write-Verbose 'Waiting for I\O to complete...'
if($IoTimeout){Write-Verbose "Timeout is $IoTimeout seconds"}
Do
{
# Check for pipelines with errors
[array]$FailedPipelines = Receive-AsyncStatus -Pipelines $AsyncPipelines | Where-Object {$_.Completed -and $_.Error}
if($FailedPipelines)
{
"$($FailedPipelines.Length) pipeline(s) failed!",
($FailedPipelines | Select-Object -ExpandProperty Error | Format-Table -AutoSize | Out-String) | Write-Debug
}
if($IoTimeout)
{
# Compare I\O start time of thread with current time
[array]$LockedReaders = $SyncHash.Keys | Where-Object {[TimeSpan]::FromTicks([DateTime]::UtcNow.Ticks - $SyncHash.$_.IoStartTime).TotalSeconds -gt $IoTimeout}
if($LockedReaders)
{
# Yikes, someone is stuck
"$($LockedReaders.Length) I\O operations reached timeout!" | Write-Verbose
$SyncHash.GetEnumerator() | ForEach-Object {"$($_.Key) = $($_.Value.Status)"} | Sort-Object | Out-String | Write-Debug
$PsCommand | ForEach-Object {
Write-Verbose "Killing process: Name=$($_.Name), Id=$($_.Id)"
Try
{
$_.Kill()
}
Catch
{
Write-Error 'Failed to kill process!'
}
}
break
}
}
Start-Sleep 1
}
While(Receive-AsyncStatus -Pipelines $AsyncPipelines | Where-Object {!$_.Completed}) # Loop until all pipelines are finished
Write-Verbose 'Waiting for all pipelines to finish...'
$IoStats = Receive-AsyncResults -Pipelines $AsyncPipelines
Write-Verbose 'All pipelines are finished'
Write-Verbose 'Collecting StdErr for all processes'
$PipeStdErr = $StdErrWorkers |
ForEach-Object {
$Encoding = $_.Src.StartInfo.StandardOutputEncoding
if(!$Encoding)
{
$Encoding = [System.Text.Encoding]::Default
}
@{
FileName = $_.Src.StartInfo.FileName
StdErr = $Encoding.GetString($_.Dst.ToArray())
ExitCode = $_.Src.ExitCode
}
} |
Select-Object @{Name = 'FileName' ; Expression = {$_.FileName}},
@{Name = 'StdErr' ; Expression = {$_.StdErr}},
@{Name = 'ExitCode' ; Expression = {$_.ExitCode}}
if($IoWorkers[-1].Dst -is [System.IO.MemoryStream])
{
Write-Verbose 'Collecting final pipeline output'
if($IoWorkers[-1].Src -is [System.Diagnostics.Process])
{
$Encoding = $IoWorkers[-1].Src.StartInfo.StandardOutputEncoding
}
if(!$Encoding)
{
$Encoding = [System.Text.Encoding]::Default
}
$PipeResult = $Encoding.GetString($IoWorkers[-1].Dst.ToArray())
}
Write-Verbose 'Closing and disposing I\O streams'
. $CleanUp
$PsCommand |
ForEach-Object {
$_.Refresh()
if(!$_.HasExited)
{
Write-Verbose "Process is still active: Name=$($_.Name), Id=$($_.Id)"
if(!$ProcessTimeout)
{
$ProcessTimeout = -1
}
else
{
$WaitForExitProcessTimeout = $ProcessTimeout * 1000
}
Write-Verbose "Waiting for process to exit (Process Timeout = $ProcessTimeout)"
if(!$_.WaitForExit($WaitForExitProcessTimeout))
{
Try
{
Write-Verbose 'Trying to kill it'
$_.Kill()
}
Catch
{
Write-Error "Failed to kill process $_"
}
}
}
Write-Verbose "Disposing process object: Name=$($_.StartInfo.FileName)"
$_.Dispose()
}
Write-Verbose 'Disposing runspace pool'
#
$RunspacePool.Dispose()
if($ForceGC)
{
Write-Verbose 'Forcing garbage collection'
Invoke-GarbageCollection
}
if(!$RawData)
{
New-Object -TypeName psobject -Property @{Result = $PipeResult ; Status = $PipeStdErr}
}
else
{
$PipeResult
}
}
}
我承认对您在管道后使用的 ruby -e "puts ARGF.read" 命令的经验为零，但我想我可以证明管道没有添加换行符。
# check length of string without newline after pipe
Write-Output "abc" | %{Write-Host "$_ has a length of: $($_.Length)" }
#check of string with newline length after pipe
Write-Output "def`n" | %{Write-Host "$($_.Length) is the length of $_" -NoNewline }
#write a string without newline (suppressing newline on Write-Host)
Write-Output 'abc' | %{ Write-Host $_ -NoNewline; }
#write a string with newline (suppressing newline on Write-Host)
Write-Output "def`n" | %{ Write-Host $_ -NoNewline; }
#write a final string without newline (suppressing newline on Write-Host)
Write-Output 'ghi' | %{ Write-Host $_ -NoNewline; }
这给了我一个输出：
abc has a length of: 3
4 is the length of def
abcdef
ghi
我想你可能想开始查看 ruby -e "put AGRF.read" 命令，看看它是否在每次读取后添加一个换行符。
以简单的方式创建一个 cmd 进程并执行它
$cmdArgs = @('/c','something.exe','arg1', .. , 'arg2' , $anotherArg , '<', '$somefile.txt' )
&'cmd.exe' $cmdArgs
完美地将信息通过管道传输到我想要的标准输入中，
澄清一些评论中的基本误解：管道中的“powershell 命令”是 cmdlet，每个命令都在 single[=24] 的进程 space 中运行=] 电源外壳。因此，对象在同一个进程中（在多个线程上）按原样传递 除非您调用外部命令。然后通过适当的格式化 cmdlet 将传递的对象转换为字符串（如果还不是字符串对象）。然后将这些字符串转换为字符流，每个字符串都有附加的 \n。所以它不是“管道”添加 \n 而是隐式转换为文本以输入到“旧版”命令。
问题中的基本问题是提问者试图在字符（字节）流输入上获得类似对象的行为（例如，没有尾随 \n 的字符串）。 （控制台）进程的标准输入流一次提供一个字符（字节）。输入 routines 将这些单独的字符收集到一个字符串中（通常）在收到 \n 时终止。 \n 是否被 returned 作为字符串的一部分取决于输入例程。当标准输入流被重定向到文件或管道时，输入例程大多不知道这一点。所以没有办法确定没有 \n 的完整字符串和有更多字符的不完整字符串之间的区别，并且 \n 还在后面。
可能的解决方案（针对字符串定界问题，而不是 powershell 添加的 \n 问题）是在标准输入读取上设置某种超时。字符串的结尾可以通过在一定时间内没有收到字符来表示。或者，如果您对管道的访问级别足够低，您可以尝试进行原子读写。通过这种方式，阻塞的读取将 return 正是写入的内容。不幸的是，当 运行 在多任务环境中时，这两种方法都存在计时问题。如果延迟很长，效率就会下降，但如果延迟太短，则可能会被进程优先级调度引起的延迟所愚弄。如果写入进程在读取进程读取当前行之前写入另一行，则调度优先级也会干扰原子读取和写入。它需要某种同步系统。
表示当前行没有更多字符的唯一其他方法是关闭管道 (EOF)，但这是一种一次性方法，因此您只能发送一个字符串（尾随 \n 或不是）。 （这就是 Ruby 知道初始示例和 Invoke-RawPipeline 示例中输入何时完成的方式。）这可能实际上是您的意图（只发送一个带或不带尾随 \ 的字符串n) 在这种情况下，您可以简单地连接所有输入（保留或重新插入任何嵌入的 \n）并丢弃最后一个 \n。
powershell 添加的多个字符串的 \n 问题的一个可能解决方案是重新定义“字符串”的编码，方法是使用无效的字符序列终止每个字符串对象。如果您有每个字符输入（不适合 C 类行输入），则可以使用 \0，否则可能使用 \377 (0xff)。这将允许您的遗留命令的输入例程“知道”字符串何时结束。序列 [=27=]\n（或 7\n）将是字符串的“结尾”，之前的所有内容（包括尾随 \n 或不包括，可能使用多次读取）将是字符串。我假设您对输入例程有一定的控制权（例如，您编写了程序），因为从标准输入读取的任何现成程序通常都需要 \n（或 EOF）来分隔其输入。