PowerShell template profile: adds some useful aliases and functions

profile.ps1

### PowerShell template profile
### Modified By: Robert Cato <saiwolf@swmnu.net>
### Forked From, and All Credit Due:

### PowerShell template profile 
### Version 1.03 - Tim Sneath <tim@sneath.org>
### From https://gist.github.com/timsneath/19867b12eee7fd5af2ba
###
### This file should be stored in $PROFILE.CurrentUserAllHosts
### If $PROFILE.CurrentUserAllHosts doesn't exist, you can make one with the following:
###    PS> New-Item $PROFILE.CurrentUserAllHosts -ItemType File -Force
### This will create the file and the containing subdirectory if it doesn't already 
###
### As a reminder, to enable unsigned script execution of local scripts on client Windows, 
### you need to run this line (or similar) from an elevated PowerShell prompt:
###   Set-ExecutionPolicy -ExecutionPolicy RemoteSigned
### This is the default policy on Windows Server 2012 R2 and above for server Windows. For 
### more information about execution policies, run Get-Help about_Execution_Policies.

# Find out if the current user identity is elevated (has admin rights)
$identity = [Security.Principal.WindowsIdentity]::GetCurrent()
$principal = New-Object Security.Principal.WindowsPrincipal $identity
$isAdmin = $principal.IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)

# Set inital prompt colors
function ConsoleDefaults {
    $host.UI.RawUI.BackgroundColor = "Black"
    $host.UI.RawUI.ForegroundColor = "Gray"
    Clear-Host
}
ConsoleDefaults

# Useful shortcuts for traversing directories
function cd... { cd ..\.. }
function cd.... { cd ..\..\.. }

# Compute file hashes - useful for checking successful downloads.
# Named after traditional *NIX Coreutils programs.
function md5sum { Get-FileHash -Algorithm MD5 $args }
function sha1sum { Get-FileHash -Algorithm SHA1 $args }
function sha256sum { Get-FileHash -Algorithm SHA256 $args }

# Quick shortcut to start notepad (Or Notepad++ if replacing notepad)
function n { notepad $args }

# Explicitly start Notepad++ if installed
function n++ {
    # Change this to your Notepad++ install path.
    $notepadplusplus = 'C:\Program Files (x86)\Notepad++'

    if ([System.IO.Directory]::Exists($notepadplusplus))
    {
        # Avoid a null-argument error for -ArgumentList
        if ($args.Count -gt 0)
        {
            Start-Process -FilePath "$notepadplusplus\notepad++.exe" -ArgumentList $args
        }
        else
        {
            Start-Process -FilePath "$notepadplusplus\notepad++.exe"
        }        
    }
    Remove-Variable -Name notepadplusplus
}

# Drive Shortcuts
function HKLM: { Set-Location HKLM: }
function HKCU: { Set-Location HKCU: }
function Env: { Set-Location Env: }

# Creates drive shortcut for Work Folders, if current user account is using it
if (Test-Path "$env:USERPROFILE\Work Folders")
{
    New-PSDrive -Name Work -PSProvider FileSystem -Root "$env:USERPROFILE\Work Folders" -Description "Work Folders"
    function Work: { Set-Location Work: }
}

# Creates drive shortcut for OneDrive, if current user account is using it
if (Test-Path HKCU:\SOFTWARE\Microsoft\OneDrive)
{
    $onedrive = Get-ItemProperty -Path HKCU:\SOFTWARE\Microsoft\OneDrive
    if (Test-Path $onedrive.UserFolder)
    {
        New-PSDrive -Name OneDrive -PSProvider FileSystem -Root $onedrive.UserFolder -Description "OneDrive"
        function OneDrive: { Set-Location OneDrive: }
    }
    Remove-Variable onedrive
}

# Set up command prompt and window title. Use UNIX-style convention for identifying 
# whether user is elevated (root) or not. Window title shows current version of PowerShell
# and appends [ADMIN] if appropriate for easy taskbar identification. The `n inserts a newline
# just in case an earlier script or module has output before the prompt is rendered.
#
# Example Output:
# [C:\Windows\System32]
# PS user@computer $> _
function prompt 
{
    $topString = "`n[" + (Get-Location) + "]"
    $bottomString = "PS " + $env:USERNAME + "@" + "$env:COMPUTERNAME"

    if (($host.Name -match "ConsoleHost") -and ($isAdmin))
    {
        $bottomString += " #>"
        Write-Host $topString -ForegroundColor Red
        Write-Host $bottomString -NoNewline -ForegroundColor Red
        return " "
    } 
    if ($isAdmin) 
    {
        $bottomString += " #>"
        Write-Host $topString -ForegroundColor Red
        Write-Host $bottomString -NoNewline -ForegroundColor Red
        return " "
    }
    else 
    {
        $bottomString += " $>"
        Write-Host $topString -ForegroundColor Green
        Write-Host $bottomString -NoNewline -ForegroundColor Green
        return " "
    }

    Remove-Variable -Name topString
    Remove-Variable -Name bottomString
}

$Host.UI.RawUI.WindowTitle = "PowerShell {0}" -f $PSVersionTable.PSVersion.ToString()
if ($isAdmin)
{
    $Host.UI.RawUI.WindowTitle += " [ADMIN]"
}

# Does the the rough equivalent of dir /s /b. For example, dirs *.png is dir /s /b *.png
function dirs
{
    if ($args.Count -gt 0)
    {
        Get-ChildItem -Recurse -Include "$args" | Foreach-Object FullName
    }
    else
    {
        Get-ChildItem -Recurse | Foreach-Object FullName
    }
}

# Simple function to start a new elevated process. If arguments are supplied then 
# a single command is started with admin rights; if not then a new admin instance
# of PowerShell is started.
function admin
{
    if ($args.Count -gt 0)
    {   
       $argList = "& '" + $args + "'"
       Start-Process "$psHome\powershell.exe" -Verb runAs -ArgumentList $argList
    }
    else
    {
       Start-Process "$psHome\powershell.exe" -Verb runAs
    }
}

# Set UNIX-like aliases for the admin command, so sudo <command> will run the command
# with elevated rights. 
Set-Alias -Name su -Value admin
Set-Alias -Name sudo -Value admin

# Make it easy to edit this profile once it's installed
function Edit-Profile
{
    if ($host.Name -match "ise")
    {
        $psISE.CurrentPowerShellTab.Files.Add($profile.CurrentUserAllHosts)
    }
    else
    {
        notepad $profile.CurrentUserAllHosts
    }
}

# We don't need these any more; they were just temporary variables to get to $isAdmin. 
# Delete them to prevent cluttering up the user profile. 
Remove-Variable identity
Remove-Variable principal

I had to use [System.IO.Directory]::Exists() instead of Test-Path for the Notepad++ function.
For some reason, Test-Path always returns false; even when the path is hard-coded.