chroot – Change the root directory to the specified destination directory

The chroot command is used to change the root directory of the current process to a specified destination directory. This command is commonly used for creating a sandbox environment for testing or for running a specific application with restricted access to the system’s files and directories. By changing the root directory, the process is limited to a specific directory and its subdirectories, which can prevent the process from accessing or modifying files outside of that directory.

Overview

The syntax for using chroot is as follows:

chroot [options] newroot [command]

• newroot: The new root directory that the process will be restricted to.
• command: The command to run after changing the root directory. If no command is specified, the user will be placed in a new shell with the new root directory as the current directory.

Examples

1. Change the root directory to /newroot and run the command /bin/bash:

chroot /newroot /bin/bash

2. Change the root directory to /newroot and run the command /bin/ls:

chroot /newroot /bin/ls

3. Change the root directory to /newroot and start a new shell:

chroot /newroot

Specific Use Cases

• Creating a sandbox environment for testing: By changing the root directory to a specific directory, the process will be limited to that directory and its subdirectories, which can prevent it from accessing or modifying files outside of that directory. This can be useful for testing applications or scripts without the risk of damaging the system’s files and directories.
• Running a specific application with restricted access: By changing the root directory to a specific directory, the process will only have access to the files and directories within that directory. This can be useful for running applications that require restricted access to the system’s files and directories.

Options

The following table lists the available options for the chroot command:

Troubleshooting Tips

• If you receive an error message that says “chroot: failed to run command ‘/bin/bash’: No such file or directory”, it may be because the specified command does not exist in the new root directory. Make sure that the command exists in the new root directory before running chroot.
• If you receive an error message that says “chroot: failed to run command ‘/bin/bash’: Permission denied”, it may be because the user running the command does not have permission to execute the specified command in the new root directory. Make sure that the user has the necessary permissions to execute the command in the new root directory.

Notes

• The chroot command is often used in conjunction with the mount command to create a complete sandbox environment.
• Be careful when using the chroot command, as it can have unintended consequences if used improperly. Always make sure that you understand the implications of changing the root directory before using this command.