Index of /links/

Commands

• awk(1) cheatsheet by Ypnose
• GNU BRE and ERE cheatsheet
• nftables quick reference
• SQL commands cheatsheet by Ypnose

HTML / CSS

• Mozilla web docs

POSIX

• sh(1)
• Utilities

Shell

• Bash FAQ
• Learning the Korn Shell (1rst edition)
• Learning the Korn Shell (2nd edition)