Soft Link vs Hard Link

What is LINK?

• A link is a pointer to a file.
• This pointer associates a file name with a number called an i-node number
• An i-node is the control structure for a file (on a UNIX/Linux file system)
• If two file names have the same i-node number, they are links to the same file
• Use the command “ls -i” to print i-node number of each file:

Type of Links:

There are two type of Links are available in Linux

1. Hard Links
2. Soft or Symbolic Links

Hard Link:

• Hard link is a reference to the block data on a file system
• More than one name can be associated with the same block  data
• Hard links can only refer to data that exists on the same file system
• Hard link can not be created for a directory
• When a file has more than one link, you can remove any one link and still be able to access the file through the remaining links.
• Hard links are alternate to the copy command as hard link not consume additional storage space on file system.
• Below reference output shows that f1 and f2  files are hard linked files having same i-node number referencing to same data block.

Symbolic Link:

• A Symbolic Link is an indirect pointer to a file – a pointer to the hard link to the file
• You can create a symbolic link to a directory
• A symbolic link can point to a file on a different file system
• A symbolic link can point to a non-existent file (referred to as a “broken link”)
• The symbolic link file and the pointed to file have different status information (e.g. file size, last modification time etc.)
• The Symbolic link to a directory has a file type of “l”  (the first letter of the permission field).
• The permissions on the link are set to “rwx” for all.
• chmod on the link applies to the actual directory (or file), the permissions on the link stay the same can point to a non-existent directory
• Below example referencing that f1 and f2 files are soft linked files having different i-node numbers but referencing to same data block.