Interpretive labor on RFC 5652 and RFC 5280
mcrcon: auto-parse password
alias mcrcon='env MCRCON_PASS="${MCRCON_PASS=$(sed -n -e '\''s/^rcon\.password=\(.\+\)/\1/p'\'' < server.properties)}" mcrcon'Javascript: calling asynchronously-initialized libraries from synchronous code
With the power of await, this isn't so difficult: let nacl, scrypt; function main() { /* Synchronous code that calls nacl and scrypt */ } (async () => { [nacl, scrypt] = await Promise.all([new Promise(nacl_factory.instantiate), new Promise(scrypt_module_factory)]); return main(); })();
Auto-updating userscripts hosted on Github Gist
In the process of crafting this small set of improvements to Advance Wars By Web, I found out about the proper URL for auto-updating userscripts which are hosted on Microsoft's "Gist" service: // @updateURL https://gist.githubusercontent.com/������/����������������/raw/�����.user.js This will always redirect to the latest version of the file.
Javascript: getElementByXPath
function getElementByXPath(path, context=null, _document=undefined) {
if( _document === undefined ) _document = document;
let res = document.evaluate(path, _document, context, XPathResult.FIRST_ORDERED_NODE_TYPE);
if( !res ) return null;
return res.singleNodeValue;
}Python: Using XOFs for general-purpose Random
As always, one's own stack overflow answers make the best blog posts. In this case, we craft a version of random.Random with a few modifications: Pulls its data from an arbitrary stream (in our case, a DRBG such as a hash function or deterministic CSPRNG) Wastes noticeably fewer bits when generating random integers Has fixed code for .shuffle, on the offchance CPython ever changes theirs, and to make it …
Python: Rounding fractions half-up
By default, Python's fractions rounds halves to the nearest even number. If you, instead, want to round a fraction but send halves up, here's how that's done:
def roundhalfup(x: Fraction) -> int:
"""
Rounds x to the nearest integer, with ties being rounded towards positive infinity
"""
return floor(x + Fraction(1, 2))Javascript: Parsing query parameters
There are at least 2×5×7×3×3×1=630 different things you might unambiguously mean by "parsing" a query string in Javascript: …
Python: Nested in-line "for" statements
You must leave the fors in the same order as in the code-block form, only popping the inner expression itself to the front:…
WordPress: Restrict MathJax to a class
I write on a variety of topics, only some of which it's appropriate to have mathematical typesetting for. To avoid triggering a math rendering engine on unrelated use of $purious dollar sign$, while activating it when $\text{necessary}\wedge\text{appropriate}$, I decided to restrict them to only elements with .language-mathjax. Here's how that's done (for v3): MathJax = { tex: { inlineMath: [ ['$', '$'] ] }, startup: { elements: ['.language-mathjax'] } …