What does it mean when a symbolic link (symlink) is red in Ubuntu?

Question

~/temp$ mkdir dir1
~/temp$ mkdir dir2
~/temp$ mkdir dir2/dir21
~/temp$ ln -s dir2/dir21 dir1/ln2dir21
~/temp$ mkdir dir1/ln2dir21/dir3
mkdir: cannot create directory ‘dir1/ln2dir21/dir3’: No such file or directory

What does the following command:

~/temp$ ln -s dir2/dir21 dir1/ln2dir21

create (there are no errors for the ln command)? The created link dir1/ln2dir21 is red and it's type is lrwxrwxrwx which seems to be a link. Then why can't create directory through that symbolic link?

Answer 1

The dir1/ln2dir21 symbolic link you created is relative to dir1.

The correct command would be:

ln -s ../dir2/dir21 dir1/ln2dir21

As another test, if you go to dir1 and create dir2/dir21 you will see that the red indicator will go away:

cd dir1
mkdir -p dir2/dir21
ll

You will see ln2dir21 -> dir2/dir21/ in normal color (no red error color).

Answer 2

~/temp$ mkdir dir1/ln2dir21/dir3 you can't create a directory in a directory that is inexistent use mkdir -p

ln -s dir2/dir21 dir1/ln2dir21 is not working, because you're a) linking to a file not a dirrectory and b) it should be a full path. https://stackoverflow.com/a/9104390

so it should be: ln -s ~/temp/dir2/dir21/ ./dir1/ln2dir21

and it should workl...