RHCSA Linux Essentials Flashcards

Which command displays the current SELinux enforcement mode?

Answer: getenforce

The `getenforce` command prints the current SELinux mode: Enforcing, Permissive, or Disabled.

What does the `umask 027` setting mean for newly created files?

Answer: Files get permissions 640

Default file permissions are 666; subtracting umask 027 gives 666-027=640 (rw-r-----) for new files.

Which systemd target is equivalent to the traditional SysV runlevel 3?

Answer: multi-user.target

multi-user.target is the systemd equivalent of runlevel 3 (multi-user, non-graphical).

A user needs to edit /etc/sudoers safely. Which command should they use?

Answer: visudo

`visudo` locks the file and validates syntax before saving, preventing a broken sudoers file.

Which command permanently sets the hostname to 'server1.example.com'?

Answer: hostnamectl set-hostname server1.example.com

`hostnamectl set-hostname` updates the hostname immediately and persists it across reboots.

What is the effect of running `chmod g+s /shared/dir`?

Answer: Files in the dir inherit the group of the directory

The setgid bit on a directory causes new files created inside to inherit the directory's group rather than the creator's primary group.

Which file contains the default shell for the root user?

Answer: /etc/passwd

The /etc/passwd file stores each user's default shell in the seventh colon-delimited field.