Changed find_git_branch to use rev-parse and find_git_dirty to use diff-files for speed (I think). Also removed preceding space in front of branch, and changed function syntax to to what the Git shell scripts use.

prompt.sh

@@ -1,29 +1,39 @@
-function find_git_branch {
-   local dir=. head branch
+find_git_branch() {
+   local branch
+   # Based on: http://stackoverflow.com/a/13003854/170413
    if branch=$(git rev-parse --abbrev-ref HEAD 2> /dev/null)
    then
    	  if [[ -z "$branch" ]]; then
    	     branch='detached'
    	  fi
-   	  git_branch=" ($branch)"
+   	  git_branch="($branch)"
    else
       git_branch=""
    fi
 }
-function find_git_dirty {
-    st=$(git status 2>/dev/null | tail -n 1)
-    if [[ $st == "" ]]; then
-        git_dirty=''
-    elif [[ $st == "nothing to commit (working directory clean)" ]]; then
-        git_dirty=''
-    else
-        git_dirty='*'
-    fi
+
+find_git_dirty() {
+	if [[ -z "$git_branch" ]]
+	then
+		git_dirty=''
+	else
+		# Based on: http://stackoverflow.com/a/2659808/170413
+		if git diff-files --quiet
+		then
+			git_dirty=''
+		else
+			git_dirty='*'
+		fi
+	fi
 }
+
 PROMPT_COMMAND="find_git_branch; find_git_dirty; $PROMPT_COMMAND"
 
 # Default Git enabled prompt with dirty state
 # export PS1="\u@\h \w\[$txtcyn\]\$git_branch\[$txtylw\]\$git_dirty\[$txtrst\]\$ "
 
+# Another variant:
+# export PS1="\[$bldgrn\]\u@\h\[$txtrst\] \w\[$bldylw\]\$git_branch\[$txtcyn\]\$git_dirty\[$txtrst\]\$ "
+
 # Default Git enabled root prompt (for use with "sudo -s")
 # export SUDO_PS1="\[$bakred\]\u@\h\[$txtrst\] \w\$ "