Create a disk usage counter

This is a simple utility that totals the size of every file in a directory and its sub-directories. It runs on both POSIX/Unix and Windows file systems.

How to do it…

This recipe is a utility to report the size of every file in a directory and its sub-directories, along with a total. We'll re-use some of the functions we've used elsewhere in this chapter:

• We start with a few convenience aliases:

  namespace fs = std::filesystem;
  using dit = fs::directory_iterator;
  using de = fs::directory_entry;

• We also use our format specialization for fs::path objects:

  template<>
  struct std::formatter<fs::path>: std::formatter<std::string> {
      template<typename FormatContext>
      auto format(const fs::path& p, FormatContext& ctx) {
          return format_to(ctx.out(), "{}", p.string());
      }
  };

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