Launch program in current PowerShell terminal

• Invoke-Expression (iex) should generally be avoided; definitely don't use it to invoke an external program or PowerShell script.

• Instead, invoke it directly (which, due to the executable path being specified via a variable, requires &, the call operator, for syntactic reasons):

& ${MY_PROGRAM} -my_program_option

If ${MY_PROGRAM} refers to a console application, it should:

• execute in the same window
• synchronously (i.e. PowerShell will wait until the application exits before continuing)
• with the application's output streams connected to PowerShell's streams, which enables directly collecting or redirecting the application's output.

As for what makes an application a console application: a flag in a given executable indicates whether it is a console-subsystem or a GUI-subsystem executable (note that these are Windows-only concepts).

Behavioral implications:

• If a given executable is a console-subsystem executable, PowerShell executes it in the same window, in the manner described above.

  • Note: This also applies to directly invoked script files that are associated with console-subsystem executables, assuming their filename extensions are listed in the $env:PATHEXT environment variable so as to allow their direct execution; e.g., .cmd or .bat.

• By contrast, a GUI-subsystem executable launches asynchronously - with no further connection to the calling session - and it is free to create its own GUI, including potentially creating a new console window, or even no UI at all.

  • You can use Start-Process if you need more control over calling such applications.