Setuid

setgid

Со стандартным ядром на директорию влияния не оказывает, но если пересобрать kernel с SUIDDIR, то начнет работать.

Executable files with this bit set will run with effective uid set to the uid of the file owner.

Для неисполняемых смысла не имеет получается?

chmod для установки используется

Что такое правка на поиск? Что за хрень 0100   For files, allow execution by owner. For directories, allow the owner to search in the directory. 0040   Allow read by group members. 0020   Allow write by group members. 0010   For files, allow execution by group members. For directo‐ ries, allow group members to search in the directory. 0004   Allow read by others. 0002   Allow write by others. 0001   For files, allow execution by others. For directories allow others to search in the directory.