What is hard link and symbolic link in Linux?

A symbolic or soft link is an actual link to the original file, whereas a hard link is a mirror copy of the original file. … Even if you delete the original file, the hard link will still has the data of the original file. Because hard link acts as a mirror copy of the original file.

A hard link is merely an additional name for an existing file on Linux or other Unix-like operating systems. Any number of hard links, and thus any number of names, can be created for any file. Hard links can also be created to other hard links.

A symbolic link, also termed a soft link, is a special kind of file that points to another file, much like a shortcut in Windows or a Macintosh alias. Unlike a hard link, a symbolic link does not contain the data in the target file. It simply points to another entry somewhere in the file system.

A soft link (also known as Symbolic link) acts as a pointer or a reference to the file name. It does not access the data available in the original file.

Soft Link :

Comparison Parameters Hard link Soft link
File system It cannot be used across file systems. It can be used across file systems.

Hard links are more forgiving when you delete a file; soft links take up less data, but soft links don’t store the actual data, or the location of the original file. Both types of links have their own quarks and uses. Creating them from the command line is easy.

To view the symbolic links in a directory:

  1. Open a terminal and move to that directory.
  2. Type the command: ls -la. This shall long list all the files in the directory even if they are hidden.
  3. The files that start with l are your symbolic link files.

The concept of a hard link is the most basic we will discuss today. Every file on the Linux filesystem starts with a single hard link. The link is between the filename and the actual data stored on the filesystem. … This means that the two filenames, though different, point to identical data.

The reason hard-linking directories is not allowed is a little technical. Essentially, they break the file-system structure. You should generally not use hard links anyway. Symbolic links allow most of the same functionality without causing problems (e.g ln -s target link ).

Hard link is the exact replica of the actual file it is pointing to . Both the hard link and the linked file shares the same inode . If the source file is deleted ,the hard link still works and you will be able to access the file until the number of hard links to file isn’t 0(zero).

To create a symbolic link, use the -s ( –symbolic ) option. If both the FILE and LINK are given, ln will create a link from the file specified as the first argument ( FILE ) to the file specified as the second argument ( LINK ).

Simplest way: cd to where the symbolic link is located and do ls -l to list the details of the files. The part to the right of -> after the symbolic link is the destination to which it is pointing.

To remove a symbolic link, use either the rm or unlink command followed by the name of the symlink as an argument. When removing a symbolic link that points to a directory do not append a trailing slash to the symlink name.

Soft and Hard links in Unix/Linux

  1. Hard Links. Each hard linked file is assigned the same Inode value as the original, therefore they reference the same physical file location. …
  2. Soft Links. A soft link is similar to the file shortcut feature which is used in Windows Operating systems.

You can check if a file is a symlink with [ -L file ] . Similarly, you can test if a file is a regular file with [ -f file ] , but in that case, the check is done after resolving symlinks. hardlinks are not a type of file, they are just different names for a file (of any type).

How do you change permissions in Unix?

To change file and directory permissions, use the command chmod (change mode). The owner of a file can change the permissions for user ( u ), group ( g ), or others ( o ) by adding ( + ) or subtracting ( – ) the read, write, and execute permissions.

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