💻 Admin

Same as Virtual Console

• cat /etc/passwd

  Displays all users

• sudo useradd -G wheel,sudo newuser

• sudo usermod -a -G existinggroup existinguser

• sudo groupadd newgroup

• usermod -a -G newgroup existinguser

• Unattended

  • echo "user:password" | chpasswd

    Only as root

• Normal

  • passwd user

    User passwd

  • sudo passwd

    Superuser passwd

RWX == Permission to Read, Write, & eXecute

• Typical user RWX

  • chmod 700

    similar to chmod +x

• Only owner has RW

  • chmod 644

• Blank out permissions

  • chmod 000

• RWX for EVERYONE

  • chmod 777

    RWX All Users & Groups (risky)

• sudo systemctl edit getty@tty1

• or

• sudo mkdir /etc/systemd/system/getty@tty1.service.d

• sudov /etc/systemd/system/getty@tty1.service.d/override.conf

  ++ [Service]
  ++ ExecStart=
  ++ ExecStart=-/sbin/agetty (check dir) --autologin weyoun ($USER) --noclear %I $TERM
  

• Reboot to check; or chroot to fix

• vim ~/.bash_profile

• or

• sudov /etc/profile

  TMOUT=300 #TMOUT=<seconds>
  readonly TMOUT
  export TMOUT
  

• sudov /etc/default/grub

• Most distributions

  -- GRUB_CMDLINE_LINUX="... splash quiet"
  ++ GRUB_CMDLINE_LINUX="..."
  

  … Typically required to boot system

• CentOS

  - -- GRUB_CMDLINE_LINUX="... rhgb quiet" #Redhat Graphical Boot
  - ++ GRUB_CMDLINE_LINUX="..."
  

• Most distributions

  • sudo update-grub

  • or

  • sudo grub-mkconfig -o /boot/grub/grub.cfg

• CentOS

  • sudo grub2-mkconfig -o /etc/grub2.cfg

    CentOS/RHEL

• sudo package_manager_install gpm

  • Select text by holding down LMB

  • Paste with RMB

  • Disable/Enable with: sudo /etc/init.d/gpm stop/start

cat /etc/*-release

• Chmod Calculator