CentOS 7 Combined Reference

(Useful for SEC260 and SYS255 and SYS265)

From SEC 260

dhclient - to use DHCP to request an ip address
Firewall:
- firewall-cmd --permanent --add-port=80/tcp - Example for adding port 80 over TCP (otherwise known as HTTP)
- firewall-cmd --reload - Reload config to apply changes
- firewall-cmd --query-port=80/tcp - Query if port 80 is open
ip addr - Show interface ip addresses
vi - Silly editor
nano - Slightly less silly editor
systemctl restart ... - Restart a running service (like httpd, or sshd)

nmtui - Edit network settings for interfaces managed by NetworkManager (like eth0)
adduser <username> - Add a new user (and home directory)
useradd -m <username> - Add a new user (and home directory) (for more options see useradd --help or man useradd)
passwd <username> - Set the password for a user
usermod -aG wheel <username> - Add a user to the wheel group (for more options see usermod --help or man usermod)
history | head -n 10 - Show the first 10 entries
systemctl start ... - Start a service (like dhcpd or sshd)
systemctl enable ... - Enable a service to auto-start on boot
chown USER:GROUP ... - Change the owner (and group if specified) of given file/directory
chmod PERMS ... - Set the permissions of file/dir to PERMS, described in this assignment
groups - Show groups your user is a member of
su ... - (S)witch (U)ser, defaults to root if not specified.