Delete get_env, which confused me a lot.

Get raw environment variables directly from main().
Add code to split on '=' in cgi_environment_vars and only pick
the ones that are interesting, just as before.

src/tawashi_implem/cgi_environment_vars.cpp

@@ -16,19 +16,64 @@
  */
 
 #include "cgi_environment_vars.hpp"
-#include "get_env.hpp"
+#include "sanitized_utf8.hpp"
 #include <utility>
+#include <unordered_map>
+#include <boost/utility/string_ref.hpp>
+#include <cassert>
+#include <cstring>
+#include <boost/functional/hash.hpp>
+
+namespace std {
+	template<>
+	struct hash<boost::string_ref> {
+		std::size_t operator() (boost::string_ref const& parStr) const {
+			return boost::hash_range(parStr.begin(), parStr.end());
+		}
+	};
+} //namespace std
 
 namespace tawashi {
-	std::vector<std::string> cgi_environment_vars() {
+	namespace {
+		std::unordered_map<boost::string_ref, boost::string_ref> get_unrefined_env_vars (const char* const* parEnvList) {
+			using boost::string_ref;
+
+			assert(parEnvList);
+			std::size_t count = 0;
+			while (*(parEnvList + count)) {
+				++count;
+			}
+
+			std::unordered_map<string_ref, string_ref> retval;
+			retval.reserve(count);
+			for (std::size_t z = 0; z < count; ++z) {
+				const char* const equal_sign = std::strchr(parEnvList[z], '=');
+				assert('=' == *equal_sign);
+				assert(equal_sign >= parEnvList[z]);
+				const std::size_t key_length = static_cast<std::size_t>(equal_sign - parEnvList[z]);
+				const std::size_t whole_length = std::strlen(parEnvList[z] + key_length) + key_length;
+				assert(std::strlen(parEnvList[z]) == whole_length);
+				assert(whole_length >= key_length + 1);
+				retval[string_ref(parEnvList[z], key_length)] = string_ref(parEnvList[z] + key_length + 1, whole_length - key_length - 1);
+			}
+			return retval;
+		}
+	} //unnamed namespace
+
+	std::vector<std::string> cgi_environment_vars (const char* const* parEnvList) {
 		using boost::string_ref;
 
 		std::vector<std::string> retlist;
 		retlist.reserve(CGIVars::_size());
 
+		auto unrefined_env_vars = get_unrefined_env_vars(parEnvList);
+
 		for (CGIVars var : CGIVars::_values()) {
-			auto value = get_env_as<std::string>(var._to_string(), "");
-			retlist.push_back(std::move(value));
+			auto it_found = unrefined_env_vars.find(var._to_string());
+			if (unrefined_env_vars.cend() != it_found)
+				retlist.push_back(sanitized_utf8(it_found->second));
+			else
+				retlist.push_back(std::string());
 		}
 		return retlist;
 	}