Question

What would be the best way to have a self updating (from SVN) Powershell script?

It should be able to start a new process and then call SVN update $script; './$script', after making sure the current process has ended.

if ((svn st -u --quiet $script) -match "\*"){
     $scriptToRun = 'SVN update $script; "./$script"'
     ##start new process that will end this process and execute $scriptToRun
}

Answer 1

I thought this would do the trick, even if a little naive. You have two scripts – StartApp.ps1 which does any necessary checks for updates. After running it then chains MainApp.ps1 which is the app itself, this is what would get updated.

StartApp.ps1 – kicks off app but also does the update check:

# Bootstrap app
#
# Check for updates here

if(some_check_to_determine_if_update_required)
{
    # Execute whatever external source control commands required but wait until 
    # done:
    Start-Process -Wait -FilePath "<path_to_svn>" -ArgumentList <args_you_need>
}

# Launch the (now possibly updated) app
.\MainApp.ps1