Tim's Technology Journey Wiki

• To check what package to install:

  yum whatprovides "*/scp"

• GB = 1,000 Megabytes
• GiB = 1,024 Megabytes
• /var = install location
• /home = user's home directories
• / = root file system, 10 GiB
• swap = temp files, 1 GiB
• Install SNMP Utils

  yum install -y net-snmp.x86_64 
  yum install -y net-snmp-utils.x86_64

chkconfig sshd on

service sshd restart

useradd tst
passwd tst
password123
password123

visudo

1. Search for line that says ##Allow root to run any commands anywhere
2. Copy root line and change username

1. For this, add a user to a group called wheel

usermod -aG wheel tst

1. Modify visudo to enable wheel group

visudo

1. Change line

## Allows people in group wheel to run all commands
# %wheel  ALL=(ALL)  ALL

1. Delete the comment in front to %wheel and the new line will look like

%wheel  ALL=(ALL)  ALL

• Register with Red Hat Subscription Manager

subscription-manager register
Username: 
Password: 
The system has been registered with ID: XXXXX

• 802.1X Authentication Tutorial
• Index all files

updatedb

• Change laptop lid closing behavior

nano /etc/systemd/logind.conf

• Change HandleLidSwitch to:
  • lock to lock the screen
  • ignore to do nothing
  • poweroff to power off the pc
• Preserve the settings upon reboot

systemctl restart systemd-logind.service

• GB = 1,000 Megabytes
• GiB = 1,024 Megabytes
• /var = install location
• /home = user's home directories
• / = root file system, 10 GiB
• swap = temp files, 1 GiB
• <CTRL> + <l> (L) to wipe screen
• mandb
  • man -k user
    • (List man pages with text 'user')
  • man -k user | wc (word count)
    • lines, words, characters
  • man -k user | grep 8
  • man -k user | grep 8 | grep create
• Start vim→Command Mode→Insert mode
  • press 'a', 'i', 'o', or <INS> to go from Command Mode to Insert Mode
  • rest of commands are like vi
  • modes:
    • i = insert
    • o = open new line
    • a = add
    • <ESC> = go back to Command Mode
    • :wq = write, quit
    • ZZ = write, quit
  • Editing
    • dd = remove a line (cut)
    • yy = copy a link (copy)
    • dd and yy are written to a buffer
    • p = paste from buffer (paste)
  • Managing
    • u = undo
    • <CTRL> + <r> = redo
    • v + arrow keys = select characters
    • :q! = quit without saving
  • Useful
    • :%s/old/new/g = look for text 'old' and replace with 'new'
      • %s = substitue
      • g = replace with
    • G = goto end of document

DATA SIZE TERMINOLOGY REFERENCE TABLE

Linux