.bash_prompt.lua

local ret_code , n_jobs = ...
ret_code = tonumber ( ret_code )
n_jobs   = tonumber ( n_jobs ) or 0

-- This MUST be updated to where ljsyscall is located
package.path = "/home/harley/Source/languages/lua/ljsyscall/?.lua;" .. package.path
local ljsyscall = require "syscall"

local getenv = os.getenv
local function cmd ( c )
  local fd = io.popen ( c )
	local ret = fd:read "*l"
	fd:close ( )
	return ret
end

local uid      = ljsyscall.geteuid()
local hostname = ljsyscall.gethostname()
local username = getenv "USER" or ""
local home     = getenv "HOME"
local pwd      = (getenv "PWD" or ljsyscall.getcwd()):gsub("^"..home,"~")

local colours = {
	black   = 30 ;
	red     = 31 ;
	green   = 32 ;
	yellow  = 33 ;
	blue    = 34 ;
	magenta = 35 ;
	cyan    = 36 ;
	white   = 37 ;
}
local function esc ( ... )
	return "\27["..table.concat({...},";").."m"
end

io.write(
	-- {HH:MM:SS:username@hostname:pwd}$
	esc(1,colours.green),"{",
	esc(0,colours.green),os.date("%H:%M:%S", os.time()),
	esc(0), ":",
	esc(1,colours.cyan),username,
	esc(0), "@",
	esc(1,colours.cyan),hostname,
	esc(0), ":",
	esc(1,colours.red),pwd,
	esc(1,colours.green),"}",esc(0)
)

local is_git = os.execute ( "git rev-parse --git-dir &> /dev/null" ) == 0
if is_git then
	local status = io.popen "git status -sb"
	local branch = status:read"*l":match("^## (.*)") -- First line is ## BRANCH NAME
	local dirty  = status:read"*l":match("^(..)") -- If there are any uncommited changes they will follow
	status:close()
	local hash = cmd "git show --format=%h"
	local col = colours.green

	-- ?? are untracked files at the end.
	-- Indicate a different colour if there are only untracked files.
	if dirty == "??" then
		col = colours.yellow
	else
		col = colours.red
	end

	-- {git:[branch:hash]}
	io.write(
		esc(1,colours.green),"{",
		esc(col), "git",
		esc(0),":",
		esc(col),"[",
		esc(0,colours.yellow), branch,
		esc(0), ":",
		esc(0,cyan), hash,
		esc(col), "]",
		esc(1,colours.green), "}",esc(0)
	)
end

local is_hg = os.execute ( "hg root &> /dev/null" ) == 0
if is_hg then
	local t = { }
	local summary = io.popen "hg summary"
	for line in  summary:lines() do
		local name , value = line:match("([^:]+): (.*)")
		if name then
			t [ name ] = value
		end
	end
	summary:close()
	local col = colours.green
	local hg_status = cmd ( "hg status" )
	if hg_status then
		col = colours.red
	elseif not t.update:match("(current)") then
		col = colours.yellow
	end
	io.write(esc(col),"hg:{",t.branch,":",t.parent:match(":(%x*)"),"} ",esc(0))
end

if n_jobs ~= 0 then
	io.write(esc(1,colours.cyan),n_jobs," jobs ",esc(0))
end

if ret_code and ret_code ~= 0 then
	io.write(esc(1,colours.red),"exit=",ret_code," ")
end

io.write (esc(1,colours.blue), uid==0 and "#" or "$", " ", esc(0) ) -- Reset

.bashrc

PROMPT_COMMAND='luajit ~/.bash_prompt.lua $? `jobs -rp | wc -l`'
PS1=""