Final Review for CEG 2350

Intro topics

1. Shells
   • Windows: powershell, cmd
   • Linux / Mac: bash, sh, zsh
2. SSH
   • the command, its options, and structure of information
   • private key files (location and permissions)
   • public keys and the authorized_keys file

Files, directories, and OS structure

1. Filesystem structure in Linux, Mac, and Windows
2. Files vs directories
3. Commands: ls, cp, mkdir, rmdir, vim, mv, rm, cd, cat, touch, head/tail, less/more
4. Importance of names and extensions (file)
5. Ownership & sharing
   • rwx permissions in Linux
   • user vs. group vs. other
   • creating users & groups (and naming rules)
   • chmod, chown, chgrp, adduser, deluser
   • sudo & the root user

Scripting

1. Environment variables
   • HOME
   • USER
   • SHELL
   • PATH
2. Aliases & customizations (.bashrc, .profile)
3. Commands: diff, find, file, wc, sort, uniq, whereis, which

4. IO streams (standard input, output (1) and error (2)) and redirection (<, >, »,

   , tee)

5. executing scripts
   • within current bash shell (source (or .)
   • by specifying interpreter (bash)
   • by specifying the interpreter with #! (./)
   • by name from any location (adding path to PATH)
6. Scripting languages: bash
   • variables
   • reading input
   • printf vs echo
   • arguments
   • conditionals (test)
   • if
   • for
   • while
   • case
   • getopts
   • functions
7. Regular expressions
8. grep (search)
9. sed (search and replace)
10. awk (manipulate formatted data)

Computer Hardware & VMs

1. Computer Hardware:
   • CPU
   • RAM
   • Motherboard
   • Disks (HDD, SSD, NVME)
   • GPU (discrete / dedicated vs integrated)
2. VMs
   • hypervisor
   • host considerations when creating VMs
   • installing guest VMs

Boot Process

1. BIOS / UEFI
2. POST
3. bootloader
4. kernel
5. OS

Filesystems & Disks

1. Devices
   • block - SSD, HDD, NVME, CD, USB
   • character - /dev/null, /dev/zero, /dev/random
2. Partition tables & partitions
   • MBR vs GPT
   • Tools: parted, gdisk, fdisk
3. Filesystems
   • Standard defaults for Windows, Linux, and Mac
   • compatibility, metadata, structure
   • inodes
     • Symbolic links vs. hard links
     • Tools: ln, stat
   • Tools: du, df, mkfs
4. Mounting & “ejecting”
   • mounting to /
   • automounting with fstab entries
   • Tools: mount, umount
5. Compression (tar & gzip)

Process Control

1. Terminology
   • process
   • application
   • service / daemon
2. Process states
   • Running
   • Sleeping
   • Stopped
   • Zombie
   • Orphan
3. Process metadata
   • PID
   • PPID
   • User
   • Command
   • Controlling terminal
4. Process manipulation
   • viewing active processes
   • killing processes
   • foreground vs background processes (bg, fg)
   • “pseudo terminals” via tmux
5. Service manipulation with systemctl
   • enable vs disable
   • start, stop, reload / restart
   • format of a service unit file
6. init / systemd
   • systemctl (manage services)
   • journalctl (view service logs)
7. Tools: ps, top, kill, jobs

Programming

1. Languages:
   • Interpreted: bash, python
   • Compiled: C / C++, Java (JDK vs JVM)
2. Compilation (in C / C++):
   • pre-processor
   • compiler
   • assembler
   • linker
   • gcc/ g++ and compilation flags
   • Linux ELF (Executable & Linkable Format)
   • Windows EXE
3. Makefiles
   • make
   • targets
   • dependencies
   • actions
4. Tools: which, whereis, ldd

Networking

1. Core networking concepts
   • Methods of communication (physical layer): wifi, ethernet, fiber
   • Network interface (NIC)
     • communicates over physical layer
     • Media Access Control address (MAC)
   • Network concepts
     • IPv4 vs IPv6 addressing
     • DNS
     • DHCP
     • subnets
     • routes
     • border gateways / Network Address Translation (NAT)
     • ports
2. IPv4 concepts
   • Subnetting & CIDR notation
3. Firewalls
   • inbound / INPUT / ingress
   • outbound / OUTPUT / egress
   • common sense rules & trusted networks
   • applied questions will be with a view of an AWS Security Group
4. Commands: ip, route, arp, iptables, ping, curl, wget

Network protocols

1. HTTP
2. HTTPS
   • certificates & Certificate Authorities
3. SSH
   • ssh
   • sftp
   • Files:
     • private key
     • public key
     • config
     • known_hosts
     • authorized_keys

Git (version control)

1. Version control as a concept
2. Steps to clone with ssh for authentication
3. Basic commands:
   • clone
   • add
   • commit
   • push
   • pull
   • status
   • branch
   • checkout
   • merge
4. Files:
   • .gitignore