Day 02: The Terminal, Shells & File Systems

🎯 Learning Objectives Understand the interface boundary between Terminal Emulators and Shell Interpreters (including Windows Terminal vs. PowerShell vs. CMD). Master File System path tracking, hidden dotfiles, and essential CLI utilities. Map system execution paths via global and local environment configurations. 1. Terminal vs. Shell (The Windows Architecture) Terminal: The visual GUI wrapper. A window application that captures keyboard strokes, handles GPU text rendering, and manages tabs/panes. Examples: Windows Terminal, iTerm2, Alacritty. Shell: The command interpreter engine running inside the terminal. It evaluates text strings, processes scripts, issues system calls ( syscalls ), and interacts with the OS Kernel. Examples: PowerShell, Bash, Zsh, Command Prompt (CMD). ┌────────────────────────────────────────────────────────┐ │ WINDOWS TERMINAL GUI (The Visual Interface Window) │ │ │ │ │ ├───► Tab 1: [ PowerShell Core Engine (Modern) ] │ │ ├───► Tab 2: [ Command Prompt Engine (Legacy) ] │ │ └───► Tab 3: [ WSL Ubuntu Linux Bash (Core) ] │ └───────────────────────────┬────────────────────────────┘ │ Raw Text & Input Streams ▼ ┌────────────────────────────────────────────────────────┐ │ SHELL INTERPRETER (e.g., PowerShell / CMD) │ │ └───► Parses input string commands into system tasks │ └───────────────────────────┬────────────────────────────┘ │ System Call (Syscall) ▼ ┌────────────────────────────────────────────────────────┐ │ OPERATING SYSTEM KERNEL │ │ └───► Interacts directly with underlying hardware │ └────────────────────────────────────────────────────────┘ 2. Deep Dive: PowerShell vs. Command Prompt (CMD) While both are Windows shells hosted inside Windows Terminal, they belong to entirely different computing eras: Command Prompt ( cmd.exe ): A legacy text shell maintained purely for backwards compatibility with 1980s MS-DOS. It pipelines data as Plain Text Only , meaning outputs must be manually string-filtered. PowerShell ( pwsh.exe ): A modern, cros