dirfd , const char * pathname , struct open_how * how , size_t size ); Note : glibc provides ... must be specified as sizeof(struct open_how) . The open_how structure The how argum…dirfd , const char * pathname , const struct open_how * how , size_t size ); Feature Test Macrodirfd , const char * pathname , const struct open_how * how , size_t size ); Feature Test Macrodirfd , const char * pathname , const struct open_how * how , size_t size ); Feature Test Macro