Linux
50 cheat sheets.
az
Cross-platform command-line interface for managing Azure resources, running ARM-based and data-plane operations from a terminal or pipeline.
nano
GNU's small, on-screen-hinted terminal text editor — the default modal-free alternative to vi/emacs that you can drive without ever learning a command vocabulary.
xidel Web Scraping & Data Extraction
Extract data from HTML, XML, and JSON using XPath, CSS selectors, pattern matching, and JSONiq from the command line.
wget
Non-interactive network downloader. Covers single and batch downloads, recursive mirroring, authentication, resuming, rate limiting, and site archiving.
vim
Bram Moolenaar's modal editor. Covers modes, verb-noun grammar, text objects, registers, marks, windows, search-and-replace, quickfix, macros, configuration, and a high-value baseline .vimrc.
tmux
Run multiple persistent terminal sessions, windows, and panes inside one shell. Covers the session/window/pane mental model, default keybindings, copy-mode, and a minimal tmux.conf.
tar
Bundle directory trees into a single archive file with optional compression. Covers create/extract/list, gzip/bzip2/xz formats, exclusions, transforms, and incremental backups.
systemd Unit Files
Writing, enabling, and managing systemd service, timer, and socket units.
SSH Tunnels & Port Forwarding
Local, remote, and dynamic SSH tunnels — port forwarding, SOCKS proxies, jump hosts, ssh_config directives, agent forwarding, autossh persistence, post-quantum key exchange, and operational recipes.
SoX
Comprehensive SoX reference covering file info, format conversion, synthesis, playback, recording, combining, effects (trim, reverb, compand, rate, pitch, tempo, noise gate), batch processing, spectrograms, and piping.
shellcheck
Catch quoting bugs, missing checks, and POSIX portability mistakes in shell scripts. Covers every flag, severity levels, inline directives, CI/pre-commit integration, and the most common rules.
sed
Non-interactive text transformation. Substitution, deletion, insertion, address ranges, in-place editing, and multi-line patterns with practical recipes.
rsync
Copy and synchronise files locally or over SSH using a delta-transfer algorithm that only sends changed parts. Covers archive mode, deletion, filtering, progress, and snapshot backups.
ripgrep (rg)
Modern grep replacement written in Rust. Respects .gitignore, searches hidden files optionally, supports PCRE2, and is significantly faster on large codebases.
qsv
Comprehensive reference for qsv: count, headers, stats, moarstats, select, search, sort, dedup, frequency, join, sqlp, luau, apply, schema, validate, sample, split, MCP server, and more — with examples and outputs.
ps, ss & netstat
Inspect running processes (ps), list network connections and listening ports (ss / netstat). Covers output formats, filtering, process trees, and socket state analysis.
permissions
POSIX file permissions on Linux. Covers symbolic and octal chmod, ownership with chown, the meaning of r/w/x for files vs. directories, setuid/setgid/sticky bits, umask, ACLs, capabilities, and immutable attributes.
PCRE
PCRE2 syntax reference — character classes, quantifiers, anchors, groups, lookarounds, backreferences, flags, and advanced features used in grep, sed, nginx, PHP, and dozens of other tools.
make
Practical Makefile patterns: targets, prerequisites, automatic variables, pattern rules, parallel builds, and a working lint/test/build/clean workflow for any project.
lsof & ss
Diagnose what's holding a port, which files a process has open, and the state of every TCP/UDP socket using lsof and the modern iproute2 ss utility.
jq
Slice, filter, map, and transform JSON data from the command line. Covers all essential filters, built-in functions, select, map, reduce, streaming, jq 1.7/1.8 additions, and real-world API response processing.
journalctl
Query and follow systemd's structured journal. Covers unit filters, time ranges, priority levels, boot logs, namespaces, invocations, output formats, persistence, configuration, and disk-vacuum.
ip
Modern replacement for ifconfig, route, and arp. Inspect and configure interfaces, addresses, routes, neighbour tables, and network namespaces with the iproute2 ip command.
ImageMagick
Comprehensive ImageMagick 7 reference covering magick, identify, mogrify, composite, montage, format conversion, resize, crop, rotate, color adjustments, effects, drawing, text, PDF operations, policy.xml hardening, and batch processing.
htop
Interactive process and resource monitor for the terminal. Covers function keys, sorting, filtering, signal sending, tree view, threads, and how to read load averages and memory correctly. Compares with top, btop, and bottom.
grep
Search files and streams using fixed strings, extended regex, or PCRE. Covers all major flags, context, recursive search, and pipeline patterns.
gpg
Practical GnuPG cheat sheet — generate keys, sign and verify files, encrypt for a recipient, sign git commits and tags, and manage trust without the bureaucracy.
git
Complete Git reference. Setup, staging, committing, branching, merging, rebasing, stashing, remotes, tags, log inspection, undoing mistakes, submodules, and power-user aliases.
gh
Complete GitHub CLI reference. Auth, configuration, repos, issues, pull requests, releases, Actions, attestations, projects, models, rulesets, caches, secrets, gists, search, API, extensions, and codespaces.
fzf
Interactive fuzzy finder for the terminal. Covers key bindings, shell integration, previews with bat and tree, multi-select, popup/tmux mode, --listen IPC, and pipelines with git, kill, and vim.
fish
Comprehensive fish shell reference covering syntax, variables, functions, abbreviations, completions, config files, path management, prompt customization, Fisher plugins, fish 4.x features (Rust rewrite), and migration from bash/zsh.
ffprobe
Comprehensive ffprobe reference for inspecting media files — formats, streams, frames, packets, chapters, metadata — with output formats (default, json, csv, xml, flat, ini), select_streams, show_entries, and one-liners for duration, fps, codec, resolution, and bitrate.
FFmpeg
Comprehensive FFmpeg reference covering transcoding, container conversion, scaling, filters, audio, subtitles, streaming, batch processing, and ffplay — with NVIDIA NVENC/NVDEC/CUDA alternatives, Vulkan compute codecs, VVC/H.266 decoding, and the FFmpeg 8.0 Whisper filter.
fd
Modern find replacement written in Rust. Simpler syntax, respects .gitignore, supports regex and glob patterns, parallel execution, and coloured output.
eza / exa
A modern ls replacement with colour coding, Git status, icons, tree view, and rich metadata. eza is the actively maintained fork of the original exa project.
dig
Query DNS records of any type from any resolver — A, AAAA, MX, TXT, NS, SOA, SRV, CAA — with formatted output, reverse lookups, and full delegation tracing.
df, du & duf
Check filesystem free space (df), measure directory sizes (du), and view a colourful disk overview (duf). Covers all key flags, human-readable output, modern alternatives (dust, gdu, ncdu), and common sysadmin recipes.
cut, paste & join
Extract columns by delimiter or byte position (cut), merge files column-wise (paste), and join on a common key field (join). Essential for tab/CSV/field-delimited data.
curl
Transfer data with URLs. Covers HTTP methods, headers, authentication, forms, TLS, cookies, proxies, timeouts, parallel downloads, and a comprehensive recipe collection.
cron
Time-based job scheduler on Unix. Covers crontab syntax, user vs. system crontabs, environment quirks, logging, anacron, and the modern systemd timer alternative.
bat
A cat clone with syntax highlighting, Git integration, line numbers, paging, and diff support. Drop-in replacement with many quality-of-life improvements for viewing files in the terminal.
Bash
Comprehensive Bash scripting reference covering variables, parameter expansion, control flow, functions, arrays, string manipulation, arithmetic, traps, process substitution, and the Bash 5.3 in-shell command substitution forms.
awk / gawk
Pattern-action language for structured text. Field splitting, built-in variables, arithmetic, string functions, arrays, BEGIN/END blocks, and practical data-processing recipes.
aria2c Download Utility
Fast, multi-protocol download utility supporting HTTP(S), FTP, SFTP, BitTorrent, and Metalink with resumption and parallel connections.
apt-get Package Management
Debian and Ubuntu package management — update, install, remove, upgrade, and maintain packages with apt-get.
Bash Redirection & Pipes
stdin, stdout, stderr redirection operators and pipeline patterns in bash.
tr & xargs
Translate, squeeze, and delete characters with tr. Build and execute command lines from stdin with xargs. Includes parallel execution, NUL safety, and pipeline recipes.
sort, uniq & wc
Sort lines (numerically, by field, human-readable sizes), deduplicate with uniq, count lines/words/bytes with wc, and number lines with nl. With real-world pipeline recipes.
find
POSIX file finder with capable expression-based filters for name, type, size, time, permissions, and ownership. Covers exec actions, pruning, and real-world recipes.
Linux
Command-line tools, shell scripting, networking, system administration, and data extraction for Linux.