A soft link is a special kind of file that just points to another file. This makes it easier to create a shortcut of a file and easy accessibility of a file to a different location in a filesystem.

To create a symbolic link of a file, the ln command is used with the -s option. For example, we will create a symbolic link of the /tmp directory in our home directory:

$ ln -s /tmp ~/local_tmp

Now, we have a symbolic link of the /tmp directory in our home directory by the name local_tmp. To access the /tmp data, we can also cd into the ~/local_tmp directory. To know whether a file is a symbolic link or not, run ls -l on a file:

$ ls -l ~/local_tmp
lrwxrwxrwx. 1 foo foo 5 Aug 23 23:31 /home/foo/local_tmp -> /tmp/

If the first character of the first column is l, then it means it is a symbolic link. Also the last column says /home/foo/local_tmp -> /tmp/, which means local_tmp is pointing to /tmp.

A hard link is a way to refer a file with different names. All such files will have the same inode number. An inode number is an index number in an inode table that contains metadata about a file.

To create a hard link of a file, use the ln command without any option. In our case, we will first create a regular file called file.txt:

$ touch file.txt
$ ls -l file.txt
-rw-rw-r--. 1 foo foo 0 Aug 24 00:13 file.txt

The second column of ls tells the link count. We can see that currently it is 1.

Now, to create a hard link of file.txt, we will use the ln command:

$ ln file.txt hard_link_file.txt

To check whether a hard link is created for file.txt, we will see its link count:

$ ls -l file.txt
-rw-rw-r--. 2 foo foo 0 Aug 24 00:13 file.txt

Now, the link count is 2 because a hard link has been created with the name hard_link_file.txt.

We can also see that the inode number of the file.txt and hard_link_file.txt files are the same:

$ ls -i file.txt hard_link_file.txt
96844   file.txt
96844   hard_link_file.txt

The following table shows a few important differences between a hard link and a soft link: