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utils.cpp

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+/* Copyright (c) 2018 Albert S.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+#include <sstream>
+#include <string>
+#include <regex>
+#include <map>
+#include <cstdlib>
+#include <fstream>
+#include "logger.h"
+#include "utils.h"
+// TODO: instead of returning vector maybe provide an iterator version too.
+
+// TODO: % may not be necessary (was in C version just to be sure against format string attacks
+// TODO: hopefully not too slow looking up every character here:
+const std::map<char, std::string> replacements = {{'<', "&lt;"}, {'>', "gt;"}, {'\"', "&quot;"}, {'%', "&#37;"}};
+std::string utils::html_xss(std::string_view str)
+{
+	std::string result;
+	int size = str.length();
+	for(int i = 0; i < size; i++)
+	{
+		char c = str[i];
+		auto val = replacements.find(c);
+		if(val != replacements.end())
+		{
+			result += val->second;
+		}
+		else
+		{
+			result += c;
+		}
+	}
+	return result;
+}
+
+std::string utils::urldecode(std::string_view str)
+{
+	std::string result;
+	int size = str.length();
+	for(int i = 0; i < size; i++)
+	{
+		char c = str[i];
+		if(c == '%' && (size - i > 1))
+		{
+			char h[3];
+			h[0] = str[i + 1];
+			h[1] = str[i + 2];
+			h[2] = 0;
+			if(std::isxdigit(h[0]) && std::isxdigit(h[1]))
+			{
+				c = std::stoi(h, 0, 16);
+				i += 2;
+			}
+		}
+		result += c;
+	}
+	return result;
+}
+
+std::vector<std::string> utils::splitByChar(const std::string &str, char delim)
+{
+	std::vector<std::string> result;
+	std::stringstream stream(str);
+	std::string item;
+	while(std::getline(stream, item, delim))
+	{
+		result.push_back(item);
+	}
+	return result;
+}
+
+// TODO: can easily break if we pass a regex here
+std::vector<std::string> utils::splitByString(const std::string &str, const std::string &delim)
+{
+	return splitByRegex(str, delim + "+");
+}
+std::vector<std::string> utils::splitByRegex(const std::string &str, const std::string &regex)
+{
+	std::vector<std::string> result;
+	std::regex reg(regex);
+	std::copy(std::sregex_token_iterator(str.begin(), str.end(), reg, -1), std::sregex_token_iterator(),
+			  std::back_inserter(result));
+	return result;
+}
+
+std::string utils::strreplace(const std::string &str, const std::string &search, const std::string &replace)
+{
+	std::string result = str;
+	auto searchlength = search.length();
+	auto replacelength = replace.length();
+	size_t pos = 0;
+	while((pos = result.find(search, pos)) != std::string::npos)
+	{
+		result = result.replace(pos, searchlength, replace);
+		pos += replacelength;
+	}
+	return result;
+}
+
+std::string utils::getenv(const std::string &key)
+{
+	const char *result = ::getenv(key.c_str());
+	if(result == nullptr)
+		return std::string();
+	return std::string{result};
+}
+
+std::string utils::readCompleteFile(std::string_view filepath)
+{
+
+	std::fstream stream(std::string{filepath});
+	std::stringstream ss;
+	ss << stream.rdbuf();
+	std::string content = ss.str();
+	return content;
+}
+
+std::string utils::regex_callback_replacer(std::regex regex, const std::string &input,
+										   std::function<std::string(std::smatch &)> callback)
+{
+	std::string result;
+	auto tagsbegin = std::sregex_iterator(input.begin(), input.end(), regex);
+	auto tagsend = std::sregex_iterator();
+	auto matchbegin = 0;
+	for(std::sregex_iterator i = tagsbegin; i != tagsend; ++i)
+	{
+		std::smatch match = *i;
+
+		auto matchlength = match.length(0);
+		auto matchpos = match.position();
+
+		result += input.substr(matchbegin, matchpos - matchbegin);
+		result += callback(match);
+		matchbegin = matchpos + matchlength;
+	}
+	result += input.substr(matchbegin);
+	return result;
+}
+
+std::string utils::toISODate(time_t t)
+{
+	struct tm *lt = localtime(&t);
+	if(lt == nullptr)
+	{
+		return {};
+	}
+	char result[20];
+	size_t x = strftime(result, sizeof(result), "%Y-%m-%d %H:%M:%S", lt);
+	if(x == 0)
+	{
+		return {};
+	}
+	return std::string{result};
+}