Switch users with su

User Privileges in Shell Environments

Overview of Root User Access

  • There are two methods to operate as a root user: the Old Way and the New Way.

  • Emphasis on using the Old Way mainly in RADEL 10 for switching user accounts in a shell environment.

Old Way: Using su Command

  • The su command (short for substitute user) allows one to switch to another user account.

  • Syntax: su - <target-user>

Environment Variables

  • Utilizing su with the minus (-) option:

    • Example: su - <target-user> enables loading the complete environment of the target user.

    • Importance: Ensures that all environment variables are set appropriately.

Password Requirement

  • When executing su, a password for the target user is required for access.

  • If switching to root user is needed, and the root has a password set, su - can be used with the root password.

  • Note: Using su - with the root user's password is generally considered bad practice.

New Way: Using sudo Command

  • A more secure method to execute commands as a different user, typically as root, without switching the shell environment.

  • Preferred Command: sudo -i (where -i stands for interactive mode).

Advantages of sudo -i

  • Prompts for the user's own password instead of the root password, enhancing security.

  • This approach prevents unnecessary exposure of the root user password.

Scope of Permissions

  • In a sudo -i environment, the user does not possess full root privileges throughout the entire environment.

  • Avoid using whoami for privilege escalation or managing tasks as root in this context.

  • Use whoami primarily for testing different user accounts' permissions, as is discussed later in the context of permissions.