Unix Create a Symbolic Link

Q. How do I create links under UNIX / Linux operating systems?

A. You need to use ln command, which is a standard Unix / Linux / BSD command, used to create links to files. There are two types of links under UNIX, hard and soft link:

Hard link vs. Soft link in Linux or UNIX

[a] Hard links cannot links directories ( cannot link /tmp with /home/you/tmp)
[b] Hard links cannot cross file system boundaries ( cannot link /tmp mounted on/tmp to 2nd hard disk mounted on /harddisk2)
[c] Symbolic links refer to a symbolic path indicating the abstract location of another file
[d] Hard links, refer to the specific location of physical data.

UNIX Create Symboliclink Command

To create a symbolic link, enter
$ ln -s {/path/to/file-name} {link-name}
$ ln -s /shared/sales/data/file.txt sales.data.txt
$ vi sales.data.txt
$ ls -l sales.data.txt

To delete a link, enter
$ rm {link-name}
$ rm sales.data.txt
$ ls -l
$ ls -l /shared/sales/data/file.txt

If you delete the soft link itself (sales.data.txt) , the data file would still be there ( /shared/sales/data/file.txt ). However, if you delete /shared/sales/data/file.txt, sales.data.txt becomes a broken link and data is lost.

UNIX Create Hardlink Command

To create hard link, enter (without the -s option):
$ ln {file.txt} {hard-link}
$ ln /tmp/file link-here

You can delete hard link with rm command itself:
$ rm {hard-link}
$ rm link-here

If you delete a hard link, your data would be there. If you delete /tmp/file your data still be accessible via link-here hard link file.

See how to create a hard links in Linux / UNIX for more information.


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