ls ~/cheat-sheets
Cheat sheets.
The commands I actually use day to day — searchable, with a copy button.
occNextcloud occ cheat sheetCopy-paste Nextcloud occ commands for admins: maintenance mode, files:scan, users, apps, missing DB indices, cron, trash bin cleanup and 2FA.digdig cheat sheetdig commands for DNS troubleshooting: A, MX, TXT, CAA, +short, +trace, reverse lookups, DNSSEC, SPF/DKIM/DMARC checks and authoritative queries.journalctljournalctl cheat sheetjournalctl commands for troubleshooting: filter logs by unit, boot, time and priority, follow live, JSON output and keep journal disk usage in check.opensslOpenSSL cheat sheetOpenSSL commands for TLS troubleshooting: check certificate chain and expiry, create a CSR, match key and cert, convert PEM/DER/PFX, test STARTTLS.nginxnginx cheat sheetEssential nginx commands and config snippets for admins: test and reload, logs, redirects, proxy_pass, rate limiting, gzip and debugging.systemctlsystemctl cheat sheetEssential systemctl commands: status, start, restart, enable, timers, drop-in overrides, systemd-analyze and targets for Linux admins.dockerDocker cheat sheetEssential Docker commands: images, containers, logs, exec, volumes, networks, Compose, cleaning up with prune and resource limits for admins.gitGit cheat sheetEssential Git commands: status, log, stash, rebase, reflog recovery, undo variants, remotes and bisect for everyday work and emergencies.