Capture EXE output in PowerShell

Question

A little background first.

I\'ve been tasked with encrypting files with a Powershell script using GPG (gnupg.org). The specific exe I\'m calling is simply gpg.exe. I

Answer 1

You need to use the --batch switch when automating GPG.EXE, as in:

& $gpgLocation --import "key.txt" --batch | out-file gpgout.txt

Without that switch, GPG may be waiting for user input.

Answer 2

Stobor's answer is great. I am adding to his answer because I needed to perform additional actions if the exe had an error.

You can also store the output of the exe into a variable like this. Then you can do error handling based on the result of the exe.

$out = $gpgLocation --import "key.txt" 2>&1
if($out -is [System.Management.Automation.ErrorRecord]) {
    # email or some other action here
    Send-MailMessage -to me@example.com -subject "Error in gpg " -body "Error:`n$out" -from error@example.com -smtpserver smtp.example.com
}
$out | out-file gpgout.txt

Answer 3

You also can use Out-Host as shown below.

& $gpgLocation --import "key.txt" | Out-Host

Answer 4

Does the output you're expecting go to standard-error or standard-out?

does this work?

& $gpgLocation --import "key.txt" 2>&1 | out-file gpgout.txt

Answer 5

Also, PowerShell simply can't capture the output of some programs because they don't write to stdout. You can verify this by running the program in PowerShell ISE (it's in the version 2.0 CTP 3)

If PowerShell ISE can't show the output in the graphical console, then you can't capture it either and may need some other way of automating the program.