Why cd .., typed at root folder, does not warn or fails with an error?I would expect:/$ cd ..-bash: cd: ..: No such file or directoryInstead, I'm left at /. Of course, this is since .. does exist in /, and is simply /, just like .. I just wonder why it is like that.
cd .. on root folder
directory;cd command
According to the Open Group (responsible for the POSIX standard):Each directory has exactly one parent directory which is represented by the name dot-dot in the first directory.  [...]  What the filename dot-dot refers to relative to the root directory is implementation-defined. In Version 7 it refers to the root directory itself; this is the behavior mentioned in POSIX.1-2008. In some networked systems the construction /../hostname/ is used to refer to the root directory of another host, and POSIX.1 permits this behavior.(Source)