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Bash Special Variables Explained: $$, $?, $@, $# and More

Thu, 22 Jan 2026 15:47:58 +0800

If you have written any Bash scripts, you have almost certainly encountered cryptic-looking variables like $?, $@, and $$. These are special parameters built into Bash that give you access to script metadata, command-line arguments, and process information. Understanding them is essential for writing robust Shell scripts.

This guide walks through every special variable with clear explanations, real-world use cases, and runnable examples.

Linux and macOS Command Cheat Sheet for Developers

Thu, 19 Mar 2020 10:55:52 +0800

The command line is an essential skill for every developer. This reference organizes the most frequently used Linux and macOS commands by category for quick lookup.

Networking

netstat — View Network Connections

Linux:

Oh My Zsh Setup Guide: Build a Productive Terminal Environment

Wed, 17 Jun 2015 00:00:00 +0000

If you spend any time in a terminal on Linux or macOS, you owe it to yourself to move beyond the default Bash experience. Zsh paired with Oh My Zsh transforms your shell into something far more capable and enjoyable to use. This guide walks you through the entire setup — from installing Zsh to fine-tuning performance — so you can get more done on the command line with less effort.