This website has been my go-to reference when hacking together Bash scripts. I can never remember the exact syntax of parameter substitution, and how do I do ar

This website has been my go-to reference when hacking together Bash scripts. I can never remember the exact syntax of parameter substitution, and how do I do arithmetic substitution again? What's all the 'set -o' options? I've since switched to Zsh, and while its documentation is extensive, it's basically one fat book and is far from being as accessible or navigable at this excellent wiki.