Just parses the git command output for a swanky prompt

PowerShell Profile for Git

# when in a git directory, outputs:
#  GIT [branch] +# ~# -# | C:\my\path
# when in any other directory, outputs:
#  PS C:\my\other\path
  
function prompt {
    Write-Host("")
    $status_string = ""
    # check to see if this is a directory containing a symbolic reference, 
    # fails (gracefully) on non-git repos.
    $symbolicref = git symbolic-ref HEAD
    if($symbolicref -ne $NULL) {
        
        # if a symbolic reference exists, snag the last bit as our
        # branch name. eg "[master]"
        $status_string += "GIT [" + `
            $symbolicref.substring($symbolicref.LastIndexOf("/") +1) + "] "
        
        # grab the differences in this branch    
        $differences = (git diff-index --name-status HEAD)
        
        # use a regular expression to count up the differences.
        # M`t, A`t, and D`t refer to M {tab}, etc.
        $git_update_count = [regex]::matches($differences, "M`t").count
        $git_create_count = [regex]::matches($differences, "A`t").count
        $git_delete_count = [regex]::matches($differences, "D`t").count
        
        # place those variables into our string.
        $status_string += "+" + $git_create_count + `
            " ~" + $git_update_count + `
            " -" + $git_delete_count + " | "
    }
    else {
        # Not in a Git environment, must be PowerShell!
        $status_string = "PS "
    }
    
    # write out the status_string with the approprate color. 
    # prompt is done!
    if ($status_string.StartsWith("GIT")) {
        Write-Host ($status_string + $(get-location)) -foregroundcolor yellow
        Write-Host "$ " -foregroundcolor white -nonewline
    }
    else {
        Write-Host ($status_string + $(get-location)) -foregroundcolor green
        Write-Host "$ " -foregroundcolor white -nonewline
    }
    return " "
 }