Question

[2] What happens when you try to create a hard link to a directory? [2] Create a new directory. In the new directory, create a new file. In the new directory, create a symbolic link to the new file with its relative path. Test that the link is really working by 'cat'ing the symbolic link. Use the mv command to move the symbolic link to another directory (either the parent or a new subdirectory. Will the symbolic link still work? Explain why or why not. What would happen if you used a hard link? Explain.

Hello I am studying IT and i need help in my course operating system ?

Answer 1

1)

An error message is thrown.

A hard link to a directory can link to a parent of itself, which creates a file system loop. For example, these commands could create a loop with the back link l:

mkdir -p /tmp/a/b
cd /tmp/a/b
ln -d /tmp/a l

A filesystem with a directory loop has infinite depth:

cd /tmp/a/b/l/b/l/b/l/b/l/b

Avoiding an infinite loop when traversing such a directory structure is somewhat difficult (though for example POSIX requires find to avoid this).

A file system with this kind of hard link is no longer a tree, because a tree must not, by definition, contain a loop.

2)

mkdir new_dir

cd new_dir

touch new_file.txt

ln -s ~/Desktop/new_dir/new_file.txt my_link.txt

cat my_link.txt

mkdir sub_dir

mv my_link.txt sub_dir/

No, the symbolic link won't work now since the relation path of the link file has changed to an invalid file path.

Once a hard link has been made the link is to the inode. deleting renaming or moving the original file will not affect the hard link as it links to the underlying inode. Any changes to the data on the inode is reflected in all files that refer to that inode.