Symlink to an existing symlink creates another symlink in the current directory

Question

When I have a symlink for a folder and then try it again with -sf option I end up having another symlink inside the original source folder symlinking to itself. Why is this happening and how do I make sure duplicate symlinks are not created ?

➜  foo pwd
/home/ubuntu/foo
➜  foo ln -sf ~/foo/bar ~/foo/baz
➜  foo tree
.
├── bar
│   └── test.sh
└── baz -> /home/ubuntu/foo/bar

2 directories, 1 file
➜  foo ln -sf ~/foo/bar ~/foo/baz
➜  foo tree
.
├── bar
│   ├── bar -> /home/ubuntu/foo/bar
│   └── test.sh
└── baz -> /home/ubuntu/foo/bar

3 directories, 1 file

Distro : Ubuntu 14.04.5 LTS (GNU/Linux 3.13.0-106-generic x86_64
shell : zsh with Oh my zsh plugin

Solution 1

I did some more googling and it points to me to use -n parameter as in this blog post.

Relevant manpage entry:

-n, --no-dereference
      treat LINK_NAME as a normal file if it is a symbolic link to a directory

Relevant answers from other communities with better explanations :

https://superuser.com/a/1061057/373342
https://superuser.com/a/645847/373342

Solution 2

The actual answer you need is, don't use -f if you don't want to actually overwrite something already existing.

Without that parameter you would actually get a message that tells you:

ln: failed to create symbolic link 'your/link': File exists

The -n is, in no case I could think of needed, unless you want to create a link with the same name inside the link pointed directory.

Comments

[Ziazis]

Huh? Doesn't make sense to me. You create a link called baz pointing to ~/foo/bar. Then you use the same command again, why would the new generated link be called bar instead of baz? You either have a copy paste error or something is not right.

[Ziazis]

What I think you actually did was first time ln -sf ~/foo/bar ~/foo/baz second time ln -sf ~/foo/bar ~/foo/bar which created the second link.

[Wordzilla]

@Ziazis Copy pasted from my terminal and it was the original output. I should have used -n option. Please refer to my answer below

[Ziazis]

ln wouldn't create another link in the same directory. It would say there is already one. Also it wouldn't randomly follow into the link itself. The -f forces it to overwrite the already created link not write inside of the link. With the -n you actually tell it to use the link as a normal directory/file and ignore it's link status.

[Wordzilla]

I ran into the situation when I ran the same script twice for testing purposes and had the options as -sf. I need the -f though because I need to link to another directory with the same name in a deployment so that I can point the current folder to the latest folder for every deployment. Your answer makes sense too. Thanks.