Start moving CGI to lua

cgi/cgi.lua

@@ -0,0 +1,90 @@
+#! /usr/bin/lua
+
+local cgi = {}
+
+cgi.POST_MAX = 512
+local getc = {}
+
+function cgi.http_error(code, name, info)
+	print(code .. " " .. name)
+	print("Allow: GET POST")
+	print("Content-type: text/html")
+	print()
+	print("<h1>" .. code .. " " .. name .. "</h1>")
+	print("<p>" .. info .. "</p>")
+	os.exit(0)
+end
+
+function cgi.init()
+	method = os.getenv("REQUEST_METHOD")
+	if (method == "POST") then
+		if (os.getenv("HTTP_CONTENT_TYPE") ~= "application/x-www-form-urlencoded") then
+			cgi.http_error(415, "Unsupported content-type", "You are sending me data in a format I can't process")
+		end
+		
+		local CL = tonumber(os.getenv("CONTENT_LENGTH")) or 0
+		if (CL > cgi.POST_MAX) then
+			cgi.http_error(413, "Post Data Too Long", "You are sending me more data than I'm prepared to handle")
+		end
+		
+		function getc()
+			if (CL > 0) then
+				CL = CL - 1
+				return io.read(1)
+			else
+				return nil
+			end
+		end
+	elseif (method == "GET") then
+		local query = os.getenv("QUERY_STRING") or ""
+		local query_pos = 0
+		local query_len = string.len(query)
+		if (query_len > cgi.POST_MAX) then
+			cgi.http_error(413, "Query Data Too Long", "You are sending me more data than I'm prepared to handle")
+		end
+		
+		function getc()
+			if (query_pos < query_len) then
+				query_pos = query_pos + 1
+				return string.sub(query, query_pos, query_pos)
+			else
+				return nil
+			end
+		end
+	else
+		cgi.http_error(405, "Method not allowed", "I only do GET and POST.")
+	end
+end
+
+function cgi.read_hex()
+	local a = getc() or 0
+	local b = getc() or 0
+
+	return string.char(tonumber(a, 16)*16 + tonumber(b, 16))
+end
+
+function cgi.item()
+	local val = ""
+
+	while (true) do
+		local c = getc()
+		if ((c == nil) or (c == "=") or (c == "&")) then
+			return val
+		elseif (c == "%") then
+			c = read_hex()
+		elseif (c == "+") then
+			c = " "
+		end
+		val = val .. c
+	end
+end
+
+function cgi.escape(s)
+	s = string.gsub(s, "&", "&amp;")
+	s = string.gsub(s, "<", "&lt;")
+	s = string.gsub(s, ">", "&gt;")
+	return s
+end
+
+return cgi
+

cgi/puzzler.cgi

@@ -0,0 +1,6 @@
+#! /usr/bin/lua
+
+local cgi = require "cgi"
+
+cgi.init()
+print(cgi.item())