int capng_apply(capng_select_t set);
capng_apply will transfer the specified internal posix capabilities settings to the kernel. The options are CAPNG_SELECT_CAPS for the traditional capabilities, CAPNG_SELECT_BOUNDS for the bounding set, or CAPNG_SELECT_BOTH if transferring both is desired.
This returns 0 on success and -1 on failure.
If you are doing multi-threaded programming, calling this function will only set capabilities on the calling thread. All other threads are unaffected. If you want to set overall capabilities for a multi-threaded process, you will need to do that before creating any threads. See the capset syscall for more information on this topic.