chroot command and examples in Linux

The chroot command in Linux/Unix systems is used to change the root directory. Every process/command in Linux/Unix-like systems has a current working directory called the root directory. It changes the root directory of the currently running process and its child processes.
Processes/commands running in such a modified environment cannot access files outside the root directory. This modified environment is called a "chroot jail" or "jail directory" . Certain root users and privileged processes are allowed to use the chroot command.

The "chroot" command is very useful:

• Create a test environment.

• Recover system or password.

• Reinstall the bootloader.

syntax:

chroot /path/to/new/root command

or

chroot /path/to/new/root/path/to/server

chroot /path/to/new/root /path/to/server

or

chroot [选项] /path/to/new/root /path/to/server

chroot [options] /path/to/new/root /path/to/server

Options:

• –userspec=USER:GROUP : This option describes the