Saturday, 22 July 2017

How to: Linux / UNIX create soft link with ln command

Two types of links

There are two types of links
  • symbolic links: Refer to a symbolic path indicating the abstract location of another file
  • hard links : Refer to the specific location of physical data.

How do I create soft link / symbolic link?

Soft links are created with the ln command. For example, the following would create a soft link named link1 to a file named file1, both in the current directory
$ ln -s file1 link1
To verify new soft link run:
$ ls -l file1 link1
Sample outputs:
-rw-r--r--  1 veryv  wheel  0 Mar  7 22:01 file1
lrwxr-xr-x  1 veryv  wheel  5 Mar  7 22:01 link1 -> file1
From the above outputs it is clear that a symbolic link named ‘link1’ contains the name of the file named ‘file1’ to which it is linked. So the syntax is as follows to create a symbolic link in Unix or Linux, at the shell prompt:
$ ln -s {source-filename} {symbolic-filename}

For example create a softlink for /webroot/home/httpd/ as /home/vivek/index.php, enter the following command:
$ ln -s /webroot/home/httpd/ /home/vivek/index.php
$ ls -l

Sample outputs:
lrwxrwxrwx 1 vivek  vivek    16 2007-09-25 22:53 index.php -> /webroot/home/httpd/
You can now edit the soft link named /home/vivek/index.php and /webroot/home/httpd/ will get updated:
$ vi /home/vivek/index.php
Your actual file /webroot/home/httpd/ remains on disk even if you deleted the soft link /home/vivek/index.php using the rm command:
$ rm /home/vivek/index.php ## <--- link gone ##
## But original/actual file remains as it is ##
$ ls -l /webroot/home/httpd/

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