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
PHP
CSRF Token Generate + Verify
Per-session CSRF token helpers using hash_equals for constant-time comparison. Token is regenerated on logout but persists across requests within a session.
@admin
Python
ThreadPoolExecutor for I/O-Bound Work
Parallelize I/O-bound tasks (HTTP requests, file reads, DB queries) without writing thread management code. The default thread count is min(32, os.cpu_count() + 4) — usually the right call.
TypeScript
Sleep / Delay
The async/await-friendly version of `setTimeout`. The one-liner everyone re-invents — keep it in a util file. Optional AbortSignal lets you cancel mid-wait.
Go
database/sql — Open + Query
`database/sql` is driver-agnostic — pick a driver (`pgx/stdlib`, `go-sql-driver/mysql`, `mattn/sqlite3`). Always `defer db.Close()` only on app exit; the pool is meant to be long-lived.
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.
Bash
Array Basics (index + iterate)
Bash 4+ arrays — declare, access by index, get all elements with [@], length with #. The quoting matters: "${arr[@]}" preserves each element; ${arr[@]} word-splits.
Rust
axum — Hello World HTTP Server
axum is the tokio-team's web framework — composable, type-safe handlers built on tower middleware. The hello-world is small enough to read in one screen.
Python
Word-Safe Truncate
Cap a string at `max_len` chars without splitting a word; append an ellipsis when truncated. Backs off to the last space if cutting mid-word would happen.
Java
Generic Method + Bounded Type Parameters
A method can have its own type parameter independent of the class. `<T extends Comparable<T>>` constrains T to types that can be compared.
PHP
Date Range Iterator
Yield each date in a [start, end] interval as a DateTimeImmutable, with a configurable step. Builds on DatePeriod under the hood — but exposes a generator so you can break out early.
PHP
Build & Sign a JWT (HS256)
Generate a JWT manually using only base64-url and hash_hmac — no library required. Demonstrates header/payload/signature concatenation and the exp claim.
PHP
Validate IP Address (v4 + v6)
Distinguish IPv4 from IPv6, optionally reject private/reserved/loopback ranges. Useful for hardening server-side fetchers against SSRF.
TypeScript
Sum / Mean / Median (numeric arrays)
The descriptive-stat trio for number[]. Median sorts a copy so the input is left alone. Empty input returns 0 / 0 / 0 rather than NaN — opinionated, but predictable.
SQL
Recursive CTE — Walk a Hierarchy
`WITH RECURSIVE` lets a CTE refer to itself. The standard way to walk parent/child trees (org charts, comment threads, category nestings) in a single query.
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.
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.
Python
asyncio.wait_for — Timeout Wrapper
Cancel a coroutine if it takes longer than `timeout` seconds. Raises asyncio.TimeoutError when fired so the caller can fall back. Python 3.11+ has asyncio.timeout() as a context-manager alternative.