Quick-n-dirty reverse-video bash and PowerShell prompts

set-prompt.ps1

# Update the following two variables to modify the window title more-or-less permanently.  Otherwise, your attempt to
# update the window title will be immediately wiped out by this prompt function.
# Update these variables from other functions like this: Set-Variable -Name PROMPT_TITLE_PREFIX -Value $title -Scope Global
$PROMPT_TITLE_PREFIX = ""
$PROMPT_TITLE_SUFFIX = ""

<#
.SYNOPSIS
    Returns true iff current PowerShell session is running with elevated privileges (i.e., "As Administrator").
.NOTES
    From http://ss64.com/ps/syntax-elevate.html
#>
function IsAdmin
{
    ([Security.Principal.WindowsPrincipal] [Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole] "Administrator")
}

function New-WindowTitle {
    $userLocn = ("{0}@{1}" -f $env:USERNAME, $(get-location))
    return ("{0} {1} {2}" -f $PROMPT_TITLE_PREFIX, $userLocn, $PROMPT_TITLE_SUFFIX)
}

function prompt
{
    # Note that DarkMagenta is the color slot used in the default PowerShell Start Menu shortcut for the console
    # window's background color.  Note also that, as of PS 2.0, the online help for Write-Host lists the colors in
    # color-slot order (if that makes any sense).

    if (IsAdmin)
    {
        $Host.UI.RawUI.WindowTitle = New-WindowTitle
        Write-Host ("PS " + $(get-location)) -nonewline -backgroundcolor gray -foregroundcolor DarkMagenta # -foregroundcolor Green
        Write-Host "#" -nonewline -backgroundcolor Gray -foregroundcolor DarkRed
        return " "
    }
    else
    {
        $Host.UI.RawUI.WindowTitle = New-WindowTitle
        Write-Host ("PS " + $(get-location) +">") -nonewline -backgroundcolor gray -foregroundcolor DarkMagenta # -foregroundcolor Green
        return " "
    }
}

set-prompt.sh

export PS1='\[\e[7m\]\h#\[\e[0m\] '

# Single quotes are important, otherwise you have to escape all your backslashes.
# \[ -- start non-printing characters
# \] -- end non-printing characters (duh?)
# \e -- ASCII ESC character
# \h -- current host name
#
# I used "#" because I'm running as root; otherwise you should probably use "$".