How to pipe all output of .exe execution in Powershell?

Question

In Powershell I am running psftp.exe which is PuTTy's homepage. I am doing this:

$cmd = "psftp.exe"
$args = '"username@ssh"@ftp.domain.com -b psftp.txt';
$output = & $cmd $args

This works; and I am printing out $output. But it only catches some output in that variable (like "Remote working directory is [...]") and is throwing other output to an error type like this:

psftp.exe : Using username "username@ssh".
At C:\full_script.ps1:37 char:20
+         $output = & <<<<  $cmd $args
    + CategoryInfo          : NotSpecified: (Using username "username@ssh".:String) [], RemoteException
    + FullyQualifiedErrorId : NativeCommandError

This "Using username ..." etc looks like a normal FTP message. How can I make sure all output gets put into $output?

Disciplinant

If you have to use the call operator (&), (which you don't if directly running psftp), the args have to be an array, like 'user@domain','-b','file.txt' – Kislev

Answer 1

The problem is some output is being sent to STDERR and redirection works differently in PowerShell than in CMD.EXE.

How to redirect output of console program to a file in PowerShell has a good description of the problem and a clever workaround.

Basically, call CMD with your executable as a parameter. Like this:

UPDATE

I fixed my code so it would actually work. :)

$args = '"username@ssh"@ftp.domain.com -b psftp.txt';
$output = cmd /c psftp.exe $args 2`>`&1

Offwhite

No quotes around the $cmd details? I tried this, but the Powershell just seems to hang now. – Disciplinant

Thanks, that somewhat worked as it didn't parse any output into an STDERR. But instead of the "Using username ..." etc now being in $output, it seems nowhere to be found. With your code, did you intend for that? – Disciplinant

I didn't have PSFTP.EXE to test with so I was using PSEXEC.EXE and $args = '-d' to test. I'll see if I can try it with PSFTP. – Offwhite

I should add that I was using PSEXEC because I know it writes some of it's output to STDERR. – Offwhite

Actually I may be mistaken; I think the STDERR is there. But appears at the end of the $output string. Intended? – Disciplinant

It should capture it in the order it is output. Where does it appear if you just run your command from the prompt without redirecting or capturing the output to a variable? – Offwhite

If you use cmd /c, it all goes to standard output anyway. – Kislev

Answer 2

Give this a try

$output = [string] (& psftp.exe 'username@[email protected]' -b psftp.txt 2>&1)

There is a PowerShell bug about 2>&1 making error records. The [string] cast works around it.

Caduceus

Can't get this to work in PowerShell 2.0. It redirects to a file named 1. – Jordain

The link is dead. – Shortcircuit

Answer 3

& "my.exe" | Out-Null    #go nowhere    
& "my.exe" | Out-Default # go to default destination  (e.g. console)
& "my.exe" | Out-String  # return a string

the piping will return it in real-time

& "my.exe" | %{    
   if ($_ -match 'OK')    
   { Write-Host $_ -f Green }    
   else if ($_ -match 'FAIL|ERROR')   
   { Write-Host $_ -f Red }   
   else    
   { Write-Host $_ }    
}

Note: If the executed program returns anything other than a 0 exitcode, the piping will not work. You can force it to pipe with redirection operators such as 2>&1

& "my.exe" 2>&1 | Out-String

sources:

https://mcmap.net/q/108076/-how-to-tell-powershell-to-wait-for-each-command-to-end-before-starting-the-next

https://social.technet.microsoft.com/forums/windowsserver/en-US/b6691fba-0e92-4e9d-aec2-47f3d5a17419/start-process-and-redirect-output-to-powershell-window

Semi