precmd() {
	local branch_ref branchless_ref

	psvar=()
	branch_ref=$(git symbolic-ref -q HEAD 2>/dev/null)
	cleanliness=""
	if [[ ! -z $(git diff-index --name-only HEAD 2>/dev/null) ]]; then
		cleanliness="*"
	fi
	# We might be on a checked out branch:
	if [[ ! -z "$branch_ref" ]]; then
		psvar[1]=$cleanliness${branch_ref#refs/heads/}
	else
		branchless_ref=$(git name-rev --name-only HEAD 2>/dev/null)
		if [[ ! -z "$branchless_ref" ]]; then
			# Or we might happen to be on the same commit as (eg) master, but not have it checked out
			psvar[2]=$cleanliness${branchless_ref#(refs/heads/|remotes/)}$cleanliness
		fi
	fi
}


export PS1="[$PR_GREEN%n$PR_WHITE@$PR_GREEN%U%m%u$PR_NO_COLOR:$PR_RED%2c$PR_NO_COLOR]%(?.$.!) "	# username, underlined host, 2 levels of current directory, '$' if last command succeeded, '!' otherwise.

# right-hand prompt:
BRANCH_PROMPT="{$PR_LIGHT_GREEN%1v$PR_NO_COLOR}"
HEADLESS_PROMPT="{$PR_LIGHT_RED%2v$PR_NO_COLOR}"
# if psvar has 2 elements, we're not on a branch, but still have a suitable git name to use.
# if psvar has 1 element, we're on a checked out branch (and obviously have a suitable git name to use)
# otherwise, use a blank right-prompt.
export RPS1="%(2v.$HEADLESS_PROMPT.%(1v.$BRANCH_PROMPT.))"