Why ln -sf does not overwrite existing link to directory

Question

According to documentation, command ln -f removes existing destination file. Does this mean that if I create a symlink, -f should remove of overwrite any existing symlink at destination?

I have a symlink, say, L, pointing to DIR1 and type ln -sf DIR2 L. But L still points to DIR1. Only after rm L this command creates a link pointing to DIR2.

With symlinks to files it behaves as expected.

What's wrong with links to directories? (bash 4.3.48 on Ubuntu 16.04.2 LTS and Windows WSL)

Answer 1

When you run:

ln -sf DIR2 L

This is creating a symlink inside DIR1, because symlink L points to directory DIR1 and ln dereferences the symlink L, resulting in creation of L/DIR2 -> DIR1.

The following:

#rm -fr DIR1 DIR2 L
mkdir DIR1 DIR2
ln -v -s DIR1 L
ls -la L
ln -v -f -s DIR2 L
ls -la L

will output:

'L' -> 'DIR1'
lrwxrwxrwx 1 runner runner 4 Oct 21 18:13 L -> DIR1
'L/DIR2' -> 'DIR2'
lrwxrwxrwx 1 runner runner 4 Oct 21 18:13 L -> DIR1

To handle that, use the --no-dereference option as indicated in answer in this thread on superuser.com.