how can I run my powershell script in line? - powershell

Question

I want to execute powershell inline , but when I try to execute everything. I got Out-Null : A positional parameter cannot be found that accepts argument 'do'.
$OutputString = 'Hello World'
$WScript = New-Object -ComObject 'wscript.shell'
$WScript.Run('notepad.exe') | Out-Null
do {
Start-Sleep -Milliseconds 100
}
until ($WScript.AppActivate('notepad'))
$WScript.SendKeys($OutputString)
inline powershell
powershell -Command $OutputString = 'Hello World';$WScript = New-Object -ComObject 'wscript.shell';$WScript.Run('notepad.exe') | Out-Null ;do{ Start-Sleep -Milliseconds 100};until($WScript.AppActivate('notepad'));$WScript.SendKeys($OutputString);
I want to get the same result inline , but I got this issue

Answer 1

Your code had 3 problems:
a missing ; before the do statement (multiple statements placed on a single line must be ;-separated in PowerShell)
you've later added that, which makes your command inconsistent with the described symptom.
a missing until keyword after do { ... }
you've later added that, but with a preceding ;, which breaks the do statement.
unescaped use of |, which means that cmd.exe itself interpreted it, not PowerShell as intended (I'm assuming you're calling this from cmd.exe, otherwise there'd be no need to call PowerShell's CLI via powershell.exe).
| must be escaped as ^| to make cmd.exe pass it through to PowerShell.
Fixing these problems yields the following command for use from cmd.exe:
# From cmd.exe / a batch file:
powershell -Command $OutputString = 'Hello World'; $WScript = New-Object -ComObject 'wscript.shell'; $WScript.Run('notepad.exe') ^| Out-Null; do{ Start-Sleep -Milliseconds 100} until ($WScript.AppActivate('notepad')); $WScript.SendKeys($OutputString)
If you do want to run your code from PowerShell, you can just invoke it directly, as shown in the first snippet in your question - there's no need to create another PowerShell process via powershell.exe
If, for some reason, you do need to create another PowerShell process, use the script-block syntax ({ ... }) to pass the command, in which case no escaping is needed:
# From PowerShell
powershell -Command { $OutputString = 'Hello World'; $WScript = New-Object -ComObject 'wscript.shell'; $WScript.Run('notepad.exe') | Out-Null; do{ Start-Sleep -Milliseconds 100} until ($WScript.AppActivate('notepad')); $WScript.SendKeys($OutputString) }