您必须在“-”运算符之后提供一个值表达式

Question

我在 PowerShell 中有一些代码，我需要在 cmd.exe

中使用它

我在cmd.exe

中使用这个命令

powershell -command "command"

但是它给我这个错误

At line:1 char:72
+ ... nt D:.txt -TotalCount 3)[-1] | Foreach-object {$_ -replace REG_SZ, ...
+                                                                  ~
You must provide a value expression following the '-replace' operator.
At line:1 char:73
+ ... 5.txt -TotalCount 3)[-1] | Foreach-object {$_ -replace REG_SZ,  } | F ...
+                                                            ~~~~~~
Unexpected token 'REG_SZ' in expression or statement.
At line:1 char:79
+ ... .txt -TotalCount 3)[-1] | Foreach-object {$_ -replace REG_SZ,  } | Fo ...
+                                                                 ~
Missing argument in parameter list.
At line:1 char:113
+ ... -object {$_ -replace REG_SZ,  } | Foreach-object {$_ -replace Gmail,  ...
+                                                                  ~
You must provide a value expression following the '-replace' operator.
At line:1 char:114
+ ... t {$_ -replace REG_SZ,  } | Foreach-object {$_ -replace Gmail,  } | s ...
+                                                             ~~~~~
Unexpected token 'Gmail' in expression or statement.
At line:1 char:119
+ ...  {$_ -replace REG_SZ,  } | Foreach-object {$_ -replace Gmail,  } | se ...
+                                                                 ~
Missing argument in parameter list.
    + CategoryInfo          : ParserError: (:) [], ParentContainsErrorRecordException
    + FullyQualifiedErrorId : ExpectedValueExpression

我的命令是：

powershell -command "(Get-Content D:.txt -TotalCount 3)[-1] | Foreach-object {$_ -replace "REG_SZ", " "} | Foreach-object {$_ -replace "Gmail", " "} | set-content D:.txt"

Answer 1

您不能使用双引号将命令和命令本身包裹起来。 Cmd.exe/Powershell.exe 将在本例中位于 "REG_SZ" 的下一个双引号处结束命令。尝试在命令中使用单引号：

powershell -command "(Get-Content D:.txt -TotalCount 3)[-1] | Foreach-object {$_ -replace 'REG_SZ', ' '} | Foreach-object {$_ -replace 'Gmail', ' '} | set-content D:.txt"

Answer 2

考虑使用 powershell.exe -EncodedCommand。要使用它，您需要将要运行的命令进行 Base64 编码，然后在命令行上发送编码后的字符串。但命令文本必须是 Unicode。运行 powershell.exe /? 在最后给出了一个例子来说明如何做到这一点：

# To use the -EncodedCommand parameter:
$command = 'dir "c:\program files" '
$bytes = [System.Text.Encoding]::Unicode.GetBytes($command)
$encodedCommand = [Convert]::ToBase64String($bytes)
powershell.exe -encodedCommand $encodedCommand

这样做的好处是您不必担心任何特殊字符，甚至是换行符，都会被命令提示符解析器误解。您可以在脚本文件中编写代码，然后将其全部转换：

# To use the -EncodedCommand parameter:
$command = (Get-Content C:\myscript.ps1) -join "`n"
$bytes = [System.Text.Encoding]::Unicode.GetBytes($command)
$encodedCommand = [Convert]::ToBase64String($bytes)
powershell.exe -encodedCommand $encodedCommand

用你的命令：

$command = @"
(Get-Content D:.txt -TotalCount 3)[-1] | Foreach-object {$_ -replace "REG_SZ", " "} | Foreach-object {$_ -replace "Gmail", " "} | set-content D:.txt
"@

$bytes = [System.Text.Encoding]::Unicode.GetBytes($command)
$encodedCommand = [Convert]::ToBase64String($bytes)
powershell.exe -encodedCommand $encodedCommand

您必须在“-”运算符之后提供一个值表达式

You must provide a value expression following the '-' operator

powershell

expression

cmd