Tags
#php
#kotlin
#bash
#go
#sql
#rust
#typescript
#html
#java
#python
#files
#utils
#strings
#http
#concurrency
#async
#json
#arrays
#security
#types
#crypto
#database
#dates
#format
Rust
HashMap with the entry() API
The `entry()` API is the idiomatic way to "insert if absent" or "update if present" in a single lookup. Avoids double-lookups that the explicit `contains_key` + `insert` dance would need.
@admin
Bash
Pretty-Print Last Exit Code
A tiny prompt-trick that shows the previous command's exit code in red when it failed. Stops you from missing silent errors in long terminal sessions.
Bash
Tail Last N Lines (no `tail` shortcuts)
`tail -n 20` works for any case where tail is available. The pure-bash version below is useful inside containers or rescue shells where coreutils is missing.
Python
Dataclass with frozen + slots + defaults
Modern dataclass essentials: immutable instances (frozen=True), tighter memory + faster attribute access (slots=True), and default_factory for mutable defaults so every instance gets its own list.
TypeScript
Retry with Exponential Backoff + Jitter
Retry an async operation up to N times, doubling the delay each attempt with random jitter to avoid thundering herd. Decide retryability via an optional predicate so 4xx errors stop immediately.
PHP
Rotating Log Writer
Append to a single log file but auto-rotate to .1/.2/.3 once the file exceeds a configurable size. No external dependencies — just rename + size check.
PHP
HMAC Webhook Signature Verify
Verify an inbound webhook (Stripe / GitHub / etc.) is genuine using HMAC-SHA256 and a shared secret. Includes timestamp tolerance to block replay attacks.
PHP
Tail Last N Lines of File
Efficiently read the last N lines of a (possibly large) file by seeking to the end and walking backwards in fixed-size chunks. Avoids loading the entire file into memory.
TypeScript
Capitalize / Title-Case
Two common case transforms. `capitalize` for the first letter only; `titleCase` for every word, with small "stop words" left lowercase except at the edges.
PHP
Simple cURL GET with Timeout
A no-dependency HTTP GET helper with sensible defaults: short timeout, follow redirects, return body as string, throw on transport error. Pass extra headers as a simple associative array.
Java
java.time — Instant, LocalDate, ZonedDateTime
Java 8's `java.time` package replaced the broken `Date`/`Calendar`. Three types you actually use: `Instant` (UTC moment), `LocalDate` (date with no tz), `ZonedDateTime` (date+time in a zone).
Python
Async Retry with Exponential Backoff
Retry an async operation up to N times, doubling the wait each attempt with random jitter to avoid thundering herd. Predicate controls retryability so 4xx errors stop immediately.
PHP
Singleton Trait
A reusable trait that turns any class into a lazily-instantiated singleton with a single ::instance() accessor. Throws on clone/wakeup to prevent accidental duplication.
PHP
Validate Hex Color
Accept #RGB, #RGBA, #RRGGBB, or #RRGGBBAA hex colors (with or without the leading #). Returns the normalized 6/8-digit lowercase form.
PHP
Validate Credit Card (Luhn check)
Apply the Luhn checksum algorithm to a credit card number. Strips spaces/dashes first. This validates the format — not whether the card actually exists or has funds.
JavaScript
Worker Pool (Web Workers)
Manages a pool of Web Workers for CPU-intensive tasks (image processing, crypto, parsing). Distributes tasks across available workers using a round-robin strategy and returns a Promise per task. Falls back gracefully to inline execution in environments where workers are unavailable.
JavaScript
Validate URL
Validates whether a string is a well-formed URL using the native URL constructor, which matches browser parsing behaviour exactly. Optionally restricts to specific protocols (defaults to http and https). No regex maintenance required — if the browser can parse it as a URL, this returns true.
JavaScript
Retry Promise with Backoff
Retries a Promise-returning function up to a specified number of times with configurable exponential backoff and optional jitter. Accepts a shouldRetry predicate so you can skip retries on specific error types (e.g. 401 Unauthorized). Returns the resolved value or re-throws the last error after exhausting retries.