Windows

Detect Windows Subsystem for Linux (WSL)

WSL can be detected by looking for the string Microsoft or microsoft in /proc/sys/kernel/osrelease, which is available in the template variable .chezmoi.kernel.osrelease, for example:

{{ if eq .chezmoi.os "linux" }}
{{   if (.chezmoi.kernel.osrelease | lower | contains "microsoft") }}
# WSL-specific code
{{   end }}
{{ end }}

Run a PowerShell script as admin on Windows

Put the following at the top of your script:

# Self-elevate the script if required
if (-Not ([Security.Principal.WindowsPrincipal] [Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole] 'Administrator')) {
  if ([int](Get-CimInstance -Class Win32_OperatingSystem | Select-Object -ExpandProperty BuildNumber) -ge 6000) {
    $CommandLine = "-NoExit -File `"" + $MyInvocation.MyCommand.Path + "`" " + $MyInvocation.UnboundArguments
    Start-Process -Wait -FilePath PowerShell.exe -Verb Runas -ArgumentList $CommandLine
    Exit
  }
}

If you use gsudo, it has tips on writing self-elevating scripts.

Notes on running elevated scripts

However you decide to run a script in an elevated prompt, as soon as the non-elevated script returns, chezmoi will move to the next step in its processing (running more scripts, creating files, etc.). Ensure that the elevated script completes before the non-elevated script exits, or subsequent steps may not run as expected. In the example above, this is accomplished by passing -Wait to PowerShell's Start-Process cmdlet.

Note that by including -NoExit in $CommandLine, the new (elevated) PowerShell process/window will not exit automatically on completion. This means you'll need to close the new window by hand for chezmoi to continue its steps. If this manual intervention is desired, it would be convenient to print a message as the script's last command to indicate completion for you to safely close the elevated window. If you want no manual intervention, you can remove -NoExit from $CommandLine, but then you likely won’t see the output of the elevated script, which will make it more difficult to determine if something went wrong during its execution.