NFD

Code snippet that performs the actions in the example:

  ptree pt;

  std::istringstream input("                               \n\
    ; comment1                                             \n\
                                                           \n\
    general ; comment2                                     \n\
    {                                                      \n\
      user user ; comment3                                 \n\
      group group                                          \n\
    }                                                      \n\
                                                           \n\
    tables                                                 \n\
    {                                                      \n\
      strategy_choice                                      \n\
      {                                                    \n\
        / /localhost/nfd/strategy/best-route               \n\
        /site /localhost/nfd/strategy/broadcast            \n\
      }                                                    \n\
    }                                                      \n\
                                                           \n\
    authorizations                                         \n\
    {                                                      \n\
      authorize                                            \n\
      {                                                    \n\
        certfile file1.cert                                \n\
      }                                                    \n\
      authorize                                            \n\
      {                                                    \n\
        certfile file2.cert                                \n\
      }                                                    \n\
    }                                                      \n\
  ");
  read_info(input, pt);

  // -s general.user -v ndn-user
  pt.put("general.user", "ndn-user");

  // -s tables.strategy_choice./site -v /localhost/nfd/strategy/broadcast
  pt.put("tables.strategy_choice./site", "/localhost/nfd/strategy/broadcast");

  // -d tables.strategy_choice./
  boost::optional<ptree&> child = pt.get_child_optional("tables.strategy_choice");
  if (child) {
    child->erase("/");
  }

  // -d authorizations
  pt.erase("authorizations");

  // -a rib.localhost_security
  ptree pt2;
  std::istringstream input2("                              \n\
    trust-anchor                                           \n\
    {                                                      \n\
      type any                                             \n\
    }                                                      \n\
  ");
  read_info(input2, pt2);
  pt.add_child("rib.localhost_security", pt2);

  write_info(std::cout, pt);

Just for the record.

Alternative to implementing an app would be to use http://augeas.net/ library that is designed for exactly the same purpose and supports multiple formats (probably not Boost.INFO, but should not be too hard to enable).