I hope this helps . Out-Null works just fine with non-PowerShell commands. However, it doesn't suppress output on STDERR, only on STDOUT. If you want to suppress output on STDERR as well you have to redirect that file descriptor to STDOUT before piping the output into Out-Null:
hg st 2>&1 | Out-Null
How to run Linux/Ubuntu commands(not executables) from Nodejs
hop of those help? Environment variables only exist in memory and are local to a process. For any running process, only the process itself can make changes to the set of environment variables "belonging" to that process, but those changes will not propagate to existing child or parent processes. In short: you cannot change an environment variable that will apply to all processes on your system (not even from a regular shell).
Difference in commands to create executables from shared library