UNIX for Dummies Questions & Answers

is /. superfluous? why not just say / ?

I can see a use for . on its own. But /. seems superfluous/redundant.

I'm guessing it must have some good reason, there's a whole website named after it!!

In many contexts /. (i.e. the current directory that is the root directory) is the same as / (the root directory) just as ./ (the directory that is the current directory) is the same as . (the current directory), e.g. they both work predictably for cd and for ls if no filename is provided.

Wikki says about slashdot the site:
!

you say in many contexts they're the same. But is there any case you can name where /. is not the same as / ? e.g. one works and the other doesn't?

note-
But regarding your use of the term 'current directory'
dot is a pointer to some directory not necessarily the current one. If you're in /home/blob/ and you do ls /. then the current directory is still /home/blob/
(pwd displays current directory, so that defines current directory) The / directory is just the one that ls is called on. I don't know of another term for the directory passed as an argument/parameter to a command. It's not (necessarily) the current/working directory. It could be any directory.

Every directory is required to have an actual entry called . and another called .. and . is required to be a link to the directory that contains it. As long as everything is hunky-dory, / and /. are pretty similar. The second one takes longer since after finding / we look inside to find . and then we open that. Should the . entry be damaged, the open might fail or it might open some other file. But I don't recall ever seeing anyone open /. in that form.

many thanks

listing /mnt shows the directory mnt in /
$ ls -ld /mnt
drwxr-xr-x 2 bin bin 512 16 Apr 2003 /mnt

listing /.mnt looks for a file called .mnt in /
$ ls -ld /.mnt
ls: 0653-341 The file /.mnt does not exist.

Interestingly
$ ls -ld /./mnt
drwxr-xr-x 2 bin bin 512 16 Apr 2003 /./mnt
and even (ad infinitum...)
$ ls -ld /./././././mnt
drwxr-xr-x 2 bin bin 512 16 Apr 2003 /./././././mnt !!

True - I got a bit tied up in definitions in the earlier post - it's only the current directory if it is at the start of a relative path (.*) and it's not necessarilly the current directory if it's absolute (/. or /etc/.) or if it's not at the start of the path (./../.) (although it could be!).

Tired now - can I have a lie down till my head stops hurting