PowerShell - Start-Process and Cmdline Switches

82
votes

I can run this fine:

$msbuild = "C:\WINDOWS\Microsoft.NET\Framework\v3.5\MSBuild.exe" 
start-process $msbuild -wait

But when I run this code (below) I get an error:

$msbuild = "C:\WINDOWS\Microsoft.NET\Framework\v3.5\MSBuild.exe /v:q /nologo" 
start-process $msbuild -wait

Is there a way I can pass parameters to MSBuild using start-process? I'm open to not using start-process, the only reason I used it was I needed to have the "command" as a variable.

When I have
C:\WINDOWS\Microsoft.NET\Framework\v3.5\MSBuild.exe /v:q /nologo
on a line by itself, how does that get handled in Powershell?

Should I be using some kind of eval() kind of function instead?

5
command-linepowershellstart-process
See blogs.msdn.com/powershell/archive/2007/01/16/… for alternatives to start-process. – i_am_jorf
Thanks jeffamaphone, this was some good reference info also. – BuddyJoe
Keep in mind that Start-Process is a new feature in V2. The information in that post is very good but some of it is not really necessary anymore in V2. – EBGreen
Start-Process itself is new to V2? Can you elaborate a little? I don't have any machine with V1 installed to test. – BuddyJoe
I just mean that the Start-Process commandlet did not exist in V1. In V1 you had to use one of the methods listed in the blog post that Jef linked. – EBGreen

5 Answers

127
votes

you are going to want to separate your arguments into separate parameter

$msbuild = "C:\WINDOWS\Microsoft.NET\Framework\v3.5\MSBuild.exe"
$arguments = "/v:q /nologo"
start-process $msbuild $arguments
63
votes

Using explicit parameters, it would be:

$msbuild = 'C:\WINDOWS\Microsoft.NET\Framework\v3.5\MSBuild.exe'
start-Process -FilePath $msbuild -ArgumentList '/v:q','/nologo'

EDIT: quotes.

7
votes

Warning

If you run PowerShell from a cmd.exe window created by Powershell, the 2nd instance no longer waits for jobs to complete.

cmd>  PowerShell
PS> Start-Process cmd.exe -Wait

Now from the new cmd window, run PowerShell again and within it start a 2nd cmd window: cmd2> PowerShell

PS> Start-Process cmd.exe -Wait
PS>

The 2nd instance of PowerShell no longer honors the -Wait request and ALL background process/jobs return 'Completed' status even thou they are still running !

I discovered this when my C# Explorer program is used to open a cmd.exe window and PS is run from that window, it also ignores the -Wait request. It appears that any PowerShell which is a 'win32 job' of cmd.exe fails to honor the wait request.

I ran into this with PowerShell version 3.0 on windows 7/x64

5
votes

I've found using cmd works well as an alternative, especially when you need to pipe the output from the called application (espeically when it doesn't have built in logging, unlike msbuild)

cmd /C "$msbuild $args" >> $outputfile

2
votes

Unless the OP is using PowerShell Community Extensions which does provide a Start-Process cmdlet along with a bunch of others. If this the case then Glennular's solution works a treat since it matches the positional parameters of pscx\start-process : -path (position 1) -arguments (positon 2).