Misc

7 sheets

256 Color Codes Cheat-SheetThe 256-colour palette used by xterm and most modern terminals, with each colour's number, name, hex, RGB and HSL value plus a swatch.
CronCron runs commands on a schedule. This sheet covers crontab syntax, the Debian/Ubuntu layout, the gotchas that make a job work in a terminal but fail under…
HTTP Status Codes444, 499 and 599 are not in the HTTP standard. 444 and 499 are nginx-specific, and 599 is used by some proxies and clients. Registered codes are in the IANA…
MarkdownMarkdown is a plain text format that converts to HTML. You write in an easy-to-read, easy-to-write syntax and tools render it. Most platforms (GitHub, GitLab…
RegexRegular expressions describe text patterns. The core is shared everywhere, but the details (escaping, \d, lookaround, backreferences) differ by flavour, so…
SSL Certificates Cheat-SheetX.509 is an ITU standard defining the format of public key certificates. X.509 certificates are used in TLS/SSL, the basis for HTTPS. An X.509 certificate…
SSL Security Cheat-SheetChecking and hardening TLS (TLS (Transport Layer Security)). Commands in OpenSSL, handshake details in TLS Handshake, certificates in SSL Certificates…