#include <regex>


// https://stackoverflow.com/questions/236129/how-do-i-iterate-over-the-words-of-a-string
std::vector<std::string> tokenize(const std::string& str,
                                  const std::string& delimiters = " ",
                                  bool               trimEmpty = false)
{
  std::vector<std::string> tokens;
  std::size_t start = 0, end, length = str.length();
  while (length && start < length + 1)
  {
    end = str.find_first_of(delimiters, start);
    if (end == std::string::npos)
    {
      end = length;
    }
    if (end != start || !trimEmpty)
      tokens.push_back(std::string(str.data() + start, end - start));
    start = end + 1;
  }
  return tokens;
}



int main(int argc, char* argv[])
{
  if (argc < 2)
  {
    fprintf(stderr, "not enough parameters\n");
    return -1;
  }

  auto args = tokenize(argv[1], "/");
  if (args.size() != 3)
  {
    fprintf(stderr, "bad argument: %s\n", argv[1]);
    return -1;
  }

  fprintf(stderr, "Using regex: %s\n", args[1].c_str());
  fprintf(stderr, "Using replace: %s\n", args[2].c_str());

  std::regex re(args[1]);

  while (!feof(stdin))
  {
    char line[1024];
    if (fgets(line, 1024, stdin))
    {
      std::string s = regex_replace(line, re, args[2].c_str());
      printf("%s\n", s.c_str());
    }
  }

  return 0;
}