Question

在调用.NET [Console]::ReadLine()读取管道输入到PowerShell.exe时，我遇到了数据丢失的问题。在CMD中，运行：

>ping localhost | powershell -NonInteractive -NoProfile -C "do {$line = [Console]::ReadLine(); ('' + (Get-Date -f 'HH:mm
:ss') + $line) | Write-Host; } while ($line -ne $null)"
23:56:45time<1ms
23:56:45
23:56:46time<1ms
23:56:46
23:56:47time<1ms
23:56:47
23:56:47

通常来自Vista64的'ping localhost'看起来像这样，所以上面的输出中缺少很多数据：


Pinging WORLNTEC02.bnysecurities.corp.local [::1] from ::1 with 32 bytes of data:
Reply from ::1: time<1ms 
Reply from ::1: time<1ms 
Reply from ::1: time<1ms 
Reply from ::1: time<1ms 

Ping statistics for ::1:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 0ms, Maximum = 0ms, Average = 0ms

但是使用C＃中的相同API会收到发送到进程的所有数据（不包括某些换行符）。代码：

namespace ConOutTime {
    class Program {
        static void Main (string[] args) {
            string s;
            while ((s = Console.ReadLine ()) != null) {
                if (s.Length > 0) // don't write time for empty lines
                    Console.WriteLine("{0:HH:mm:ss} {1}", DateTime.Now, s);
            } 
        }
    }
}

输出：

00:44:30 Pinging WORLNTEC02.bnysecurities.corp.local [::1] from ::1 with 32 bytes of data:
00:44:30 Reply from ::1: time<1ms
00:44:31 Reply from ::1: time<1ms
00:44:32 Reply from ::1: time<1ms
00:44:33 Reply from ::1: time<1ms
00:44:33 Ping statistics for ::1:
00:44:33     Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
00:44:33 Approximate round trip times in milli-seconds:
00:44:33     Minimum = 0ms, Maximum = 0ms, Average = 0ms

因此，如果从PowerShell调用相同的API而不是C＃，StdIn的许多部分都会被“吃掉”。 PowerShell主机是否从StdIn读取字符串，即使我没有使用'PowerShell.exe -Command - '？

Answer 1

您可以使用PowerShell中的$input枚举器来访问传输到程序中的数据。我也发现[Console]::ReadLine()在某种程度上做得很少甚至没有。但不明原因。

C:\Users\Me> ping localhost | powershell -noninteractive -noprofile -c "$input|%{(date -f HH:mm:ss)+' '+$_}"

07:31:54
07:31:54 Pinging Sigmund [::1] with 32 bytes of data:
07:31:54 Reply from ::1: time<1ms
07:31:54 Reply from ::1: time<1ms
07:31:54 Reply from ::1: time<1ms
07:31:55 Reply from ::1: time<1ms
07:31:55
07:31:55 Ping statistics for ::1:
07:31:55     Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
07:31:55 Approximate round trip times in milli-seconds:
07:31:55     Minimum = 0ms, Maximum = 0ms, Average = 0ms

C:\Users\Me>ping localhost

Pinging Sigmund [::1] with 32 bytes of data:
Reply from ::1: time<1ms
Reply from ::1: time<1ms
Reply from ::1: time<1ms
Reply from ::1: time<1ms

Ping statistics for ::1:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 0ms, Maximum = 0ms, Average = 0ms

Answer 2

一个可能的解决方案是：

powershell -NonInteractive -NoProfile -C  "ping localhost | % { ('' + (Get-Date -f 'HH:mm:ss') + $_) | Write-Host; }"

我正在为其他问题访问者添加它，因为我认为你有一些理由不使用它：）

Answer 3

我正在提交我的最终解决方案，即使这不是我最初问题的答案。我试图从拥有大量专用工具的cmd.exe环境中将数据传输到powershell（请参阅www.streambase.com）。最后，我将这些工具添加到我的PowerShell环境中。

我最终在PowerShell中调用了外部工具，并且管道输出到Out-Time高级功能......

function Out-Time { 
param (
    [parameter(ValueFromPipeline=$true)]
    $Value, 
    [switch] $OutputEmptyLines=$false) 
process {
    if (!$OutputEmptyLines -and ($Value -eq $null -or $Value -eq '')) {
    } 
    else {
        "{0} {1}" -f @((get-date -Format "HH:mm:ss.ff"), $Value)
    }
} 
}
#test
#ping localhost | Out-Time; ping localhost | Out-Time -OutputEmpty

使用[Console] :: ReadLine（）时未收到通过PowerShell.exe传送的文本

3 个答案: