立即启动 powershell 和命令

Question

if I do this in a powershell:

echo beep ; echo beep

it prints:

beep
beep

but if I do this in a regular console:

powershell -command { echo beep ; echo beep }

it prints:

echo beep ; echo beep

what is the correct syntax to obtain the same result ?

Answer 1

Passing a list of commands inside a script block ( { ... } ) to powershell -Command for execution as-is is only supported from within PowerShell itself , as running powershell -h will tell you.

From outside of PowerShell, simply pass the commands as-is, but preferably inside double quotes, so as to prevent unintended up-front interpretation of the arguments by cmd.exe :

powershell -command "echo beep ; echo beep"

Note, however, that cmd.exe -style environment-variable references (eg, %USER% ) are still expanded up front.

Alternatively, you could pass a script block (string) ^[1] preceded by & , the call operator to ensure the script block's execution , but that is only necessary if you want to pass arguments to the script block:

powershell -command "& { echo $Args[0]; echo $Args[0] } beep"

beep is passed as the 1st argument, which the script block references as $Args[0] .

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As an aside: In PowerShell echo is an alias of Write-Output , which writes to the success output stream; the output from any command or expression that isn't captured or redirected implicitly goes to the output stream, so that use of echo / Write-Output is generally unnecessary:

powershell -command "& { $Args[0]; $Args[0] } beep"

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^{[1] From inside PowerShell, passing a script block to powershell -command causes the calling PowerShell session to recognize it and to treat the enclosed commands as the ones to pass to the new session to execute.
From outside of PowerShell, {...} is a string passed to the new session, and it is the new session that then parses that string as PowerShell code. Evaluating a script block by itself, without explicit invocation via & (or . ), simply outputs the literal contents of the script block, which explains your output; you can verify this behavior by submitting
{ echo beep; echo beep } { echo beep; echo beep } at the PowerShell prompt.}