c++permissionsboost-interprocess

Setting permission for shared memory created by boost


We open a boost shared memory that was created by another process like this

  boost::interprocess::managed_shared_memory segment(boost::interprocess::open_only, "SharedMem");

But if the process that created the shared memory was a root user, then the process reading it, if it was a normal user, will fail with the reason as:

terminate called after throwing an instance of 'boost::interprocess::interprocess_exception'
what():  Permission denied

What should i do to avoid this? that is to give permission to the shared memory to all?


Solution

  • If you look at the shared_memory constructor, it takes a permissions object. boost::interprocess::permissions::set_unrestricted is probably what you are looking for

    void set_unrestricted();
    //Sets permissions to unrestricted access:
    //        A null DACL for windows or 0666 for UNIX.
    

    According to this, it was added in 1.45 version