Learn error with wget command using PowerShell & Batch File

Question

I have a power shell script that invokes a .cmd file. Here the architecture looks like

-PowerShell File Code

$arguments='/savecred /profile /user:myDomain\myuser "cmd /c C:\Users\myuser\code.cmd"' Start-Process cmd.exe $arguments -Wait

• .cmd code file

Here the code invokes wget request to download a file

wget .....(command here)

My goal is to learn at PowerShell command prompt (after completing Start-Process command) whether the wget command executed successfully or some error like 401, 404 occurred during the execution. Here I am particular not interested in the type of error, just need to know whether error occurred or not.

Answer 1

Not sure if this is what you are asking but you could test none-zero return code of the last command using $? variable, which will be $false if return code is not zero.

Let's say you have a test.cmd file which simply returns 5:

exit 5

If you run it within PowerShell, you can look at the result of $?

if ($?) {"No error"} else {"some error"}

Here is a link for more info: http://blogs.technet.com/b/heyscriptingguy/archive/2011/05/12/powershell-error-handling-and-why-you-should-care.aspx

Answer 2

Using $? with Start-Process isn't going to work:

C:\PS> Start-Process cmd.exe -arg '/c exit 5'
C:\PS> $?
True

If you want to use Start-Process, you can go this route:

C:\PS> $p = Start-Process cmd.exe -arg '/c exit 5' -PassThru -Wait
C:\PS> $p.ExitCode
5

Or you could just invoke cmd.exe directly:

C:\PS> cmd /c exit 5
C:\PS> $LASTEXITCODE
5

In this last example you could use $? but I prefer $LastExitCode since some brain-damaged console apps return non-zero for success. Regarding calling cmd.exe and using $LASTEXITCODE see this ScriptingGuy blog post.

For a handy CheckLastExitCode function look through this blog post for an implementation of the function.