⌨️ Command Line

jq cheat sheet for the command line: selecting values, select filters, reshaping objects, arrays and math, string helpers, output flags, and error meanings.

Your network blocks SSH on port 22, not your key. Route GitHub over ssh.github.com on port 443, make it permanent in ssh config, and verify with git.

GitHub rejects your Git password over HTTPS. Switch the remote to SSH, or create a personal access token and store it, so pushes stop asking.

SSH offers every key you own and the server cuts you off after six. Pin one key with IdentitiesOnly, and learn why GitHub gives a different error.

SSH stops with "Host key verification failed." Read the warning correctly, decide whether the key really changed, and fix it without disabling checking.

Git rejects the push with "src refspec main does not match any". Four causes: no commit yet, a different branch name, a typo, and nothing committed.

Query Kubernetes with kubectl -o json and jq: find pods that aren't running, containers without limits, images in use, restart counts, and node capacity.

jq vs yq compared on YAML support, syntax, speed, and in-place edits, with tested examples and a pick for each job. They are complements, not rivals.

fzf is a fuzzy finder that turns file selection into a fast, interactive search. Learn how it speeds up opening files in Neovim, macOS apps, and shell workflows.

Zoxide is a smarter cd that learns your most-used directories and jumps to them with a short query. Learn how frecency ranking replaces path typing.

Nushell is a modern shell that uses structured data instead of text streams. Understand why Nushell exists, how it works, and when to use it.

Learn tmux step-by-step: installation, commands, sessions, panes, and workflows for productive terminal work.

Discover tmux, a terminal multiplexer that lets you manage multiple terminal sessions, detach and reattach to them, and keep your work running even when connections drop.

Learn Neovim by practicing in real Neovim in your browser, then set up plugins with vim.pack, lazy.nvim, or LazyVim. Includes a searchable command reference.

Learn how to use sqlite-utils to manage SQLite databases from the command line. Includes examples for creating databases, tables, and performing CRUD operations.

jq use cases and a tested cookbook for parsing JSON: when to reach for jq, select and filter, reshape objects, group and sum, and convert JSON to CSV.

Learn systemd by doing: the systemctl commands you need daily, reading logs with journalctl, writing a service unit, and replacing a cron job with a timer.

Install bash on windows for fun and profit. Learn how to install it with various methods. Learn about the benefits it will provide.

Learn how to create a custom Quick Action in Automator to open Hyper Terminal from Finder on macOS. Step-by-step guide with screenshots and troubleshooting tips.

Fix "Permission denied (publickey)" in SSH and Git: use the git user, load your key into ssh-agent, add it to GitHub, and set key file permissions.