Linux

Certifications

Red Hat Certified Server Administrator

Concepts

Getting Help

Input and Output Redirects

File Management

Pipes

Text Editors

User Account Management

You can use the following:

• useradd
• groupadd
• userdel
• groupdel
• usermod

You can check if a user is created with id username, you can also check to see if it created a home directory for that user.

Switching Users

You can switch user with su, this is in the format su - username.

SSH with Keys

You can set up keys to allow SSH with keys rather than providing a username and password.

To do this, you create keys on the host machine and run a commmand to copy them across to the remote machine.

# on the host machine, generate the keys
ssh-keygen

# copy the key across
ssh-copy-id root@123.123.123.123

# login
ssh root@123.123.123.123
ssh -l root 123.123.123.13