capng_print_caps_numeric man page
capng_print_caps_numeric — print numeric values for capabilities set
char *capng_print_caps_numeric(capng_print_t where, capng_select_t set);
capng_print_caps_numeric will create a numeric representation of the internal capabilities. The representation can be sent to either stdout or a buffer by passing CAPNG_PRINT_STDOUT or CAPNG_PRINT_BUFFER respectively for the where parameter. If the option was for a buffer, this function will malloc a buffer that the caller must free.
The set parameter controls what is included in the representation. The legal options are CAPNG_SELECT_CAPS for the traditional capabilities, CAPNG_SELECT_BOUNDS for the bounding set, or CAPNG_SELECT_BOTH if clearing both is desired.
If CAPNG_PRINT_BUFFER was selected for where, this will be the text buffer and NULL on failure. If CAPNG_PRINT_STDOUT was selected then this value will be NULL no matter what.