tests whether this filedescriptor is valid . concode_field_sep FileDescriptor out concode_elem_sep FileDescriptor in concode_elem_sep FileDescriptor err concode_elem_sep int descriptor concode_field_sep String toString concode_elem_sep int getInt$ concode_elem_sep void setInt$ concode_elem_sep void sync
boolean function ( ) { return descriptor != - 1 ; }