Let's start with the opening act!
Users
Standard User
Super User / Administrator
Root
Why?
- Better control
- Restricted Permissions
- Multiple users can work in synchrony
Restricted Permission?
How?
Groups
Group ID: A
Users: a, b, c
Group ID: B
Users: b, c
Group ID: C
Users: c
Permissions
Read
Write
Execute
4
2
1
Demo Time!
- `ls -l`
- whoami
- groups
- id
- su
- sudo
- sudo id
- chmod
User management
create/remove users
User details stored
| Action | Command |
|---|---|
| Create user | `useradd <user>` |
| Change Password | `passwd <user>` |
| Modify user | `usermod -L <user>` `usermod -U <user>` |
| Delete user | |
| Adding new group | `groupadd -g 4001 <group> ` |
| Add user to new group | `usermod -aG <group> <user>` |
Cheat Sheet !
Softwares and packages
Why do we need software?
How to install software?
Package managers
The software to install software
But why?
Dependencies
Package manager
Demo Time!
- sudo dnf install vim
- man dnf
- dnf search <package-name>
- dnf list updates
- dnf updateinfo list --security
- dnf update
Bash
The bourne Shell
How to access shell?
Terminal Emulators
Shell Scripts
Shell scripts?
A script/file with shell (bash) instructions
But why?
Demo time!
SSH
Secure Shell Protocol
Port: 22
What is SSH?
-
Network Protocol used for remote administration
-
Created in 1995 by Tatu Ylönen, SSH protocol
-
Uses Public-key based authentication for controlled access
Why SSH?
And
Alternatives?
rlogin
telnet
ftp
How it works?
How to connect?
- SSH client
- Access permission (User and password)
- Server address (IP/URL)
ssh <user>@<ip-address>
-v: verbose
-i: identify file (.pem file)
Processes & Services
- Each program in execution is a process
- All processes are tracked by Operating system
- Linux keep process details in /etc/proc
Lifecycle of process
Process management?
View all active processes
ps
-a: all process
-u: for users in userlist
Services
Set of processes
How to manage services?
systemd
Systemd: service manager
- Check status
- Start service
- Stop service
- Control service
systemd
status
<service>
start
stop
enable
Logging
Questions?
Thank you!
Kernel (Drivers)
LearningTheLinux
By Mohit Bansal
LearningTheLinux
A filler talk on how open source evolved over time and how git came into picture. The skills that can be useful to start contributing in open source, both technical and non-technical.
