max1220/cgi_helpers.lua

## cgi_helpers.lua
-- helper function common for all CGI

local t_insert = table.insert
local t_concat = table.concat
local t_remove = table.remove
local s_gfind = string.gfind or string.gmatch
local s_gsub = string.gsub
local s_char = string.char
local s_format = string.format
local i_write = io.write
local o_getenv = os.getenv
local _G = _G or _ENV
local tostring = tostring

-- Use LFS if it's possible
local ok, lfs = pcall(require, "lfs")
if not ok then
  lfs = nil
end


function kvtostring(t, kToStr, strToNum)
  -- Converts table elements and optional indexes to strings
  --[[
    kvtostring({hello=123, foo=true}) --> {hello="123", foo="true"}
  ]]
  local ret = {}
  for k,v in pairs(t) do
    if kToStr then
      ret[tostring(k)] = tostring(v)
    else
      ret[k] = tostring(v)
    end
  end
  return ret
end

function tconcat(t, sep)
  return t_concat(kvtostring(t,false, true), sep)
end

function tcontains(t, v)
  for k,t_v in pairs(t) do
    if t_v == v then
      return k, v
    end
  end
  return false
end


function filter(t, f)
  -- Filters a Table based on a function
  --[[
    filter({42, 1337, 123, 1234}, function(v) if v%2 == 0 then return true end end) --> {42, 1234}
  ]]
  local newt = {}
  for k,v in ipairs(t) do
    if f(v, k) then
      table.insert(newt, v)
    end
  end
end

function color(str, color)
  local colors = { black=0, red=1, green=2, yellow=3, blue=4, magenta=5, cyan=6, white=7 }
  local color = color or colors.red
  if type(color) == "string" then
    if colors[color] then
      color = 90 + colors[color]
    elseif color:sub(1, #"bright") == "bright" and colors[color:sub(#"bright" + 1)] then
      color = "1;" .. 90 + colors[color:sub(#"bright" + 1)]
    end
  end
  return string.char(27) .. "[" .. color .. "m" .. tostring(str) .. string.char(27) .. "[m"
end

function logger(logpath, logdate, dateformat, stderr, logcolor)
  -- Creates a function that logs to a file.
  --[[
  example.lua:
    log = loggerToFile("log.txt", false)
    log("Hello World!")
  log.txt:
    Hello World!
  ]]
  local dateformat = dateformat or "%c"
  local logfile = io.open(logpath, "a")
  if not logfile then
    logfile = assert(io.open(logpath, "a"), "Can't open logfile!")
  end
  local function log(...)
    local logstr = ""
    if logdate then
     logstr = os.date(dateformat) .. "\t"
    end


    logstr = logstr .. tconcat({...}, "\t")
    if stderr then
      io.stderr:write(color(logstr, logcolor), "\n")
    end
    logfile:write(logstr, "\n")
    logfile:flush()
  end
  local function logf(str, ...)
    return log(str:format(...))
  end
  return log, logf
end

function pack(...)
  -- Takes all arguments and packs them in a table. (Reverse unpack)
  --[[
    pack("foo", "bar", "buzz") --> {"foo, "bar", "buzz"}
  ]]
  return {...}
end

function htmlescape(str)
  -- Removes HTML controll characters from a string
  --[[
    name = "<script>doBadStuff()</script>"
    htmlescape("Hello " .. name .. "!") --> "Hello &lt;script&gt;doBadStuff()&lt;/script&gt;!"
  ]]
	str = s_gsub(str, "&", "&amp;")
  for k,v in pairs({["<"]="&lt;", [">"]="&gt;", ['"']="&quot;", ["'"]="&#39;"}) do
    str = s_gsub(str, k, v)
  end
  return str
end

function templateFromFile(filepath, removeUnused, escape)
  -- Creates a template, which is a function that renders parameters into a template.
  --[[
  example.template:
    <html>
      <head>
        <title>{{title}}</title>
      </head>
      <body>
        {{body}}
      </body>
    </html>
  example.lua:
    mainTemplate = templateFromFile("example.template")
    function get(name)
      return mainTemplate{
        title = "Hello World!",
        body = "<h1>Hello World!</h1>"
      }
    end
  ]]--
  local file = assert(io.open(filepath, "r"), "Can't open template file!")
  local template = file:read("*a")
  return function(inserts)
    local ret = template
    for k,v in pairs(inserts) do
      if escape then
        ret = s_gsub(ret, "{{" .. htmlescape(tostring(k)) .. "}}", htmlescape(tostring(v)))
      else
        ret = s_gsub(ret, "{{" .. tostring(k) .. "}}", tostring(v))
      end
    end
    if removeUnused then
      return (s_gsub(ret, "({{.-}})", ""))
    else
      return ret
    end
  end
end

function unescape (str)
  -- Removes URL escape characters(Converts "+" to " " and "%XX" to it's correct character value)
  --[[
    unescape("Hello+World%21") --> "Hello World!"
  ]]
  str = s_gsub(str, "+", " ")
  str = s_gsub(str, "%%(..)", function (hex)
    return s_char(tonumber(hex, 16))
  end)
  return str
end

function urldecode(str)
  -- Seperates URL encoded key=value pairs to a lua table
  --[[
    urldecode("foo=bar&list=a&list=b&list=c") --> { foo="bar", list={ "a", "b", "c" } }
  ]]
  local parms = {}
  for name, value in s_gfind(str, "([^&=]+)=([^&=]+)") do
    local name = unescape(name)
    local value = unescape(value)
    if type(parms[name]) == "table" then
      t_insert(parms[name], value)
    elseif parms[name] then
      local orig = parms[name]
      parms[name] = {orig, value}
    else
      parms[name] = value
    end
  end
  return parms
end

function urlencode(str)
  -- Makes a string URL-useable by replacing illegal digits with their correct notation
  --[[
    urlencode("Hello World!") --> "Hello+World%21"
  ]]
  if (str) then
    -- str = string.gsub (str, "\n", "\r\n")
    str = s_gsub (str, "([^%w %-%_%.%~])", function (c)
      return string.format ("%%%02X", string.byte(c))
    end)
    str = s_gsub (str, " ", "+")
  end
  return str
end

function CSVtoTable(str, indexes)
  -- Reads a CSV string into a table.
  --[[
    example.lua:
      csv = readFile("example.csv")
      for _,fruit in pairs(CSVtoTable(csv, {"name", "color"})) do
        printf("The fruit %q has the color %q", fruit.name, fruit.color)
      end
    example.csv:
      #format: [name],[color]
      apple,red
      banana,yellow
      tomato,red
  ]]
  local indexes = indexes or {}
  local function lineToTable(line)
    local parts = {}
    while true do
      if line:find(",") then
        t_insert(parts, line:sub(1, line:find(",") - 1))
        line = line:sub(line:find(",") + 1, -1)
      else
        t_insert(parts, line)
        break
      end
    end
    local ret = {}
    for k,v in pairs(parts) do
      if indexes[k] then
        ret[indexes[k]] = v
      else
        ret[k] = v
      end
    end
    return ret
  end
  local ret = {}
  for line in s_gfind(str, "[^\r\n]+") do
    if trim(line):sub(1,1) ~= "#" then
      t_insert(ret, lineToTable(line))
    end
  end
  return ret
end

function trim(str)
  -- Trims(removes leading/trailing whitespace) a string
  --[[
    trim("   Hello World!    ") --> "Hello World!"
  ]]
  return string.match(str, "^%s*(.-)%s*$")
end

function readFile(path)
  -- Reads a file, returns it's content
  --[[
    example.lua:
      readFile("example.txt") --> "Hello World!"
    example.txt:
      Hello World!
  ]]
  local file = assert(io.open(path, "r"))
  local content = file:read("*a")
  file:close()
  return content
end

function writeFile(path, content)
  -- Writes a file
  --[[
    example.lua:
      writeFile("example.txt", "Hello World!")
    example.txt:
      Hello World!
  ]]
  local file = assert(io.open(path, "w"), "Can't open file for writing!")
  file:write((assert(content, "Missing Content!")))
  file:close()
  return true
end

if lfs then
  function scanDir(pwd)
    local ret = {files = {}, dirs = {}, pwd = pwd}
    for file in lfs.dir(pwd) do
      if file ~= "." and file ~= ".." then
        local attrs = lfs.attributes(pwd .. "/" .. file)
        if attrs and attrs.mode == "directory" then
          ret.dirs[file] = scanDir(pwd .. "/" .. file)
        elseif attrs and attrs.mode == "file" then
          table.insert(ret.files, file)
        else
          print("Not path or directory: ", file)
        end
      end
    end
    return ret
  end
end


function concater(...)
  local t = {...}
  return function(append, ...)
    if append and type(append) == "string" then
      table.insert(t, append .. table.concat({...}))
    end
    return table.concat(t)
  end
end


function printf(str, ...)
  -- prints a formated string. (For format, see lua's string.format)
  --[[
    example.lua:
      printf("Hello %s!", "World") --> prints "Hello World!"
  ]]
  print(s_format(str, ...))
end

function dispatchHandlers(errhandler, prefix)
  -- Reads the CGI parameters, and calls a global handler function(e.g. HTTP_GET). If an error occurs, errhandler is called.
  --[[
    cgi-bin/example.lua:
      function HTTP_GET(parms)
        io.write("Content-type: text/plain\n\nParameter listing:")
        for k,v in pairs(parms) do
          io.write(" ", tostring(k), "\t", tostring(v))
        end
      end
      dispatchHandlers()
  ]]
  local getenv
  if type(fakeenv) == "table" then
    getenv = function(key)
      return fakeenv[key]
    end
  else
    getenv = o_getenv
  end
  local errhandler = errhandler or function(err)
      i_write("Content-type: text/plain\n\n  An error occured!\n " .. ("="):rep(78) .. "\nThe occured error was:\n\n" .. tostring(err))
      os.exit(1)
  end
  local prefix = prefix or "HTTP_"
  local req_method = assert(os.getenv("REQUEST_METHOD"), "Missing REQUEST_METHOD!"):upper()
  local request_handler = assert(_G[prefix .. req_method], "Unknown REQUEST_METHOD!")
  local query_parms = urldecode(assert(os.getenv("QUERY_STRING"), "Missing QUERY_STRING!"))
  local ret = pack(pcall(request_handler, query_parms))
  if t_remove(ret, 1) then
    i_write(unpack(kvtostring(ret)))
  else
    i_write(errhandler(unpack(kvtostring(ret))))
  end
end
	-- helper function common for all CGI

	local t_insert = table.insert
	local t_concat = table.concat
	local t_remove = table.remove
	local s_gfind = string.gfind or string.gmatch
	local s_gsub = string.gsub
	local s_char = string.char
	local s_format = string.format
	local i_write = io.write
	local o_getenv = os.getenv
	local _G = _G or _ENV
	local tostring = tostring

	-- Use LFS if it's possible
	local ok, lfs = pcall(require, "lfs")
	if not ok then
	lfs = nil
	end





	function kvtostring(t, kToStr, strToNum)
	-- Converts table elements and optional indexes to strings
	--[[
	kvtostring({hello=123, foo=true}) --> {hello="123", foo="true"}
	]]
	local ret = {}
	for k,v in pairs(t) do
	if kToStr then
	ret[tostring(k)] = tostring(v)
	else
	ret[k] = tostring(v)
	end
	end
	return ret
	end

	function tconcat(t, sep)
	return t_concat(kvtostring(t,false, true), sep)
	end

	function tcontains(t, v)
	for k,t_v in pairs(t) do
	if t_v == v then
	return k, v
	end
	end
	return false
	end


	function filter(t, f)
	-- Filters a Table based on a function
	--[[
	filter({42, 1337, 123, 1234}, function(v) if v%2 == 0 then return true end end) --> {42, 1234}
	]]
	local newt = {}
	for k,v in ipairs(t) do
	if f(v, k) then
	table.insert(newt, v)
	end
	end
	end

	function color(str, color)
	local colors = { black=0, red=1, green=2, yellow=3, blue=4, magenta=5, cyan=6, white=7 }
	local color = color or colors.red
	if type(color) == "string" then
	if colors[color] then
	color = 90 + colors[color]
	elseif color:sub(1, #"bright") == "bright" and colors[color:sub(#"bright" + 1)] then
	color = "1;" .. 90 + colors[color:sub(#"bright" + 1)]
	end
	end
	return string.char(27) .. "[" .. color .. "m" .. tostring(str) .. string.char(27) .. "[m"
	end

	function logger(logpath, logdate, dateformat, stderr, logcolor)
	-- Creates a function that logs to a file.
	--[[
	example.lua:
	log = loggerToFile("log.txt", false)
	log("Hello World!")
	log.txt:
	Hello World!
	]]
	local dateformat = dateformat or "%c"
	local logfile = io.open(logpath, "a")
	if not logfile then
	logfile = assert(io.open(logpath, "a"), "Can't open logfile!")
	end
	local function log(...)
	local logstr = ""
	if logdate then
	logstr = os.date(dateformat) .. "\t"
	end


	logstr = logstr .. tconcat({...}, "\t")
	if stderr then
	io.stderr:write(color(logstr, logcolor), "\n")
	end
	logfile:write(logstr, "\n")
	logfile:flush()
	end
	local function logf(str, ...)
	return log(str:format(...))
	end
	return log, logf
	end

	function pack(...)
	-- Takes all arguments and packs them in a table. (Reverse unpack)
	--[[
	pack("foo", "bar", "buzz") --> {"foo, "bar", "buzz"}
	]]
	return {...}
	end

	function htmlescape(str)
	-- Removes HTML controll characters from a string
	--[[
	name = "<script>doBadStuff()</script>"
	htmlescape("Hello " .. name .. "!") --> "Hello <script>doBadStuff()</script>!"
	]]
	str = s_gsub(str, "&", "&")
	for k,v in pairs({["<"]="<", [">"]=">", ['"']=""", ["'"]="'"}) do
	str = s_gsub(str, k, v)
	end
	return str
	end

	function templateFromFile(filepath, removeUnused, escape)
	-- Creates a template, which is a function that renders parameters into a template.
	--[[
	example.template:
	<html>
	<head>
	<title>{{title}}</title>
	</head>
	<body>
	{{body}}
	</body>
	</html>
	example.lua:
	mainTemplate = templateFromFile("example.template")
	function get(name)
	return mainTemplate{
	title = "Hello World!",
	body = "<h1>Hello World!</h1>"
	}
	end
	]]--
	local file = assert(io.open(filepath, "r"), "Can't open template file!")
	local template = file:read("*a")
	return function(inserts)
	local ret = template
	for k,v in pairs(inserts) do
	if escape then
	ret = s_gsub(ret, "{{" .. htmlescape(tostring(k)) .. "}}", htmlescape(tostring(v)))
	else
	ret = s_gsub(ret, "{{" .. tostring(k) .. "}}", tostring(v))
	end
	end
	if removeUnused then
	return (s_gsub(ret, "({{.-}})", ""))
	else
	return ret
	end
	end
	end

	function unescape (str)
	-- Removes URL escape characters(Converts "+" to " " and "%XX" to it's correct character value)
	--[[
	unescape("Hello+World%21") --> "Hello World!"
	]]
	str = s_gsub(str, "+", " ")
	str = s_gsub(str, "%%(..)", function (hex)
	return s_char(tonumber(hex, 16))
	end)
	return str
	end

	function urldecode(str)
	-- Seperates URL encoded key=value pairs to a lua table
	--[[
	urldecode("foo=bar&list=a&list=b&list=c") --> { foo="bar", list={ "a", "b", "c" } }
	]]
	local parms = {}
	for name, value in s_gfind(str, "([^&=]+)=([^&=]+)") do
	local name = unescape(name)
	local value = unescape(value)
	if type(parms[name]) == "table" then
	t_insert(parms[name], value)
	elseif parms[name] then
	local orig = parms[name]
	parms[name] = {orig, value}
	else
	parms[name] = value
	end
	end
	return parms
	end

	function urlencode(str)
	-- Makes a string URL-useable by replacing illegal digits with their correct notation
	--[[
	urlencode("Hello World!") --> "Hello+World%21"
	]]
	if (str) then
	-- str = string.gsub (str, "\n", "\r\n")
	str = s_gsub (str, "([^%w %-%_%.%~])", function (c)
	return string.format ("%%%02X", string.byte(c))
	end)
	str = s_gsub (str, " ", "+")
	end
	return str
	end

	function CSVtoTable(str, indexes)
	-- Reads a CSV string into a table.
	--[[
	example.lua:
	csv = readFile("example.csv")
	for _,fruit in pairs(CSVtoTable(csv, {"name", "color"})) do
	printf("The fruit %q has the color %q", fruit.name, fruit.color)
	end
	example.csv:
	#format: [name],[color]
	apple,red
	banana,yellow
	tomato,red
	]]
	local indexes = indexes or {}
	local function lineToTable(line)
	local parts = {}
	while true do
	if line:find(",") then
	t_insert(parts, line:sub(1, line:find(",") - 1))
	line = line:sub(line:find(",") + 1, -1)
	else
	t_insert(parts, line)
	break
	end
	end
	local ret = {}
	for k,v in pairs(parts) do
	if indexes[k] then
	ret[indexes[k]] = v
	else
	ret[k] = v
	end
	end
	return ret
	end
	local ret = {}
	for line in s_gfind(str, "[^\r\n]+") do
	if trim(line):sub(1,1) ~= "#" then
	t_insert(ret, lineToTable(line))
	end
	end
	return ret
	end

	function trim(str)
	-- Trims(removes leading/trailing whitespace) a string
	--[[
	trim(" Hello World! ") --> "Hello World!"
	]]
	return string.match(str, "^%s(.-)%s$")
	end

	function readFile(path)
	-- Reads a file, returns it's content
	--[[
	example.lua:
	readFile("example.txt") --> "Hello World!"
	example.txt:
	Hello World!
	]]
	local file = assert(io.open(path, "r"))
	local content = file:read("*a")
	file:close()
	return content
	end

	function writeFile(path, content)
	-- Writes a file
	--[[
	example.lua:
	writeFile("example.txt", "Hello World!")
	example.txt:
	Hello World!
	]]
	local file = assert(io.open(path, "w"), "Can't open file for writing!")
	file:write((assert(content, "Missing Content!")))
	file:close()
	return true
	end

	if lfs then
	function scanDir(pwd)
	local ret = {files = {}, dirs = {}, pwd = pwd}
	for file in lfs.dir(pwd) do
	if file ~= "." and file ~= ".." then
	local attrs = lfs.attributes(pwd .. "/" .. file)
	if attrs and attrs.mode == "directory" then
	ret.dirs[file] = scanDir(pwd .. "/" .. file)
	elseif attrs and attrs.mode == "file" then
	table.insert(ret.files, file)
	else
	print("Not path or directory: ", file)
	end
	end
	end
	return ret
	end
	end


	function concater(...)
	local t = {...}
	return function(append, ...)
	if append and type(append) == "string" then
	table.insert(t, append .. table.concat({...}))
	end
	return table.concat(t)
	end
	end





	function printf(str, ...)
	-- prints a formated string. (For format, see lua's string.format)
	--[[
	example.lua:
	printf("Hello %s!", "World") --> prints "Hello World!"
	]]
	print(s_format(str, ...))
	end

	function dispatchHandlers(errhandler, prefix)
	-- Reads the CGI parameters, and calls a global handler function(e.g. HTTP_GET). If an error occurs, errhandler is called.
	--[[
	cgi-bin/example.lua:
	function HTTP_GET(parms)
	io.write("Content-type: text/plain\n\nParameter listing:")
	for k,v in pairs(parms) do
	io.write(" ", tostring(k), "\t", tostring(v))
	end
	end
	dispatchHandlers()
	]]
	local getenv
	if type(fakeenv) == "table" then
	getenv = function(key)
	return fakeenv[key]
	end
	else
	getenv = o_getenv
	end
	local errhandler = errhandler or function(err)
	i_write("Content-type: text/plain\n\n An error occured!\n " .. ("="):rep(78) .. "\nThe occured error was:\n\n" .. tostring(err))
	os.exit(1)
	end
	local prefix = prefix or "HTTP_"
	local req_method = assert(os.getenv("REQUEST_METHOD"), "Missing REQUEST_METHOD!"):upper()
	local request_handler = assert(_G[prefix .. req_method], "Unknown REQUEST_METHOD!")
	local query_parms = urldecode(assert(os.getenv("QUERY_STRING"), "Missing QUERY_STRING!"))
	local ret = pack(pcall(request_handler, query_parms))
	if t_remove(ret, 1) then
	i_write(unpack(kvtostring(ret)))
	else
	i_write(errhandler(unpack(kvtostring(ret))))
	end
	end