How does hostname command work internally in Linux?

The hostname command in Linux is used to display or set the system's hostname. The command retrieves the current hostname from the system's configuration and can also modify it if the user has the necessary permissions.

Internally, when the hostname command is executed, it interacts with the kernel and the system's networking configuration. The kernel maintains the current hostname in its data structures, and tools like hostname can access and modify this information using system calls.

To simply display the current hostname, the command performs a read operation on the hostname stored in the kernel. If you use the command to change the hostname, it typically updates the system's network settings, which might involve writing to files like /etc/hostname and notifying other parts of the system to recognize the change.

Here’s a simple example of using the hostname command: