How to tell PowerShell to wait for each command to end before starting the next?

Question

I have a PowerShell 1.0 script to just open a bunch of applications. The first is a virtual machine and the others are development applications. I want the virtual machine to finish booting before the rest of the applications are opened.

In bash I could just say "cmd1 && cmd2"

This is what I've got...

C:\Applications\VirtualBox\vboxmanage startvm superdooper     &"C:\Applications\NetBeans 6.5\bin\netbeans.exe" 

Answer 1

Normally, for internal commands PowerShell does wait before starting the next command. One exception to this rule is external Windows subsystem based EXE. The first trick is to pipeline to Out-Null like so:

Notepad.exe | Out-Null 

PowerShell will wait until the Notepad.exe process has been exited before continuing. That is nifty but kind of subtle to pick up from reading the code. You can also use Start-Process with the -Wait parameter:

Start-Process <path to exe> -NoNewWindow -Wait 

If you are using the PowerShell Community Extensions version it is:

$proc = Start-Process <path to exe> -NoNewWindow -PassThru $proc.WaitForExit() 

Another option in PowerShell 2.0 is to use a background job:

$job = Start-Job { invoke command here } Wait-Job $job Receive-Job $job 

Answer 2

Besides using Start-Process -Wait, piping the output of an executable will make Powershell wait. Depending on the need, I will typically pipe to Out-Null, Out-Default, Out-String or Out-String -Stream. Here is a long list of some other output options.

# Saving output as a string to a variable. $output = ping.exe example.com | Out-String  # Filtering the output. ping stackoverflow.com | where { $_ -match '^reply' }  # Using Start-Process affords the most control. Start-Process -Wait SomeExecutable.com 

I do miss the CMD/Bash style operators that you referenced (&, &&, ||). It seems we have to be more verbose with Powershell.