ls ~/cheat-sheets
Cheat sheets.
The commands I actually use day to day — searchable, with a copy button.
occNextcloud occ cheat sheetThe essential 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.