Bash

Wait For Service With Timeout

Block until a TCP port accepts connections, with a deadline. Used everywhere in docker-compose entrypoints — wait for the DB to be ready before running the app.

1h ago 0

Java

Files.readString / readAllLines

`java.nio.file.Files` shipped these convenience helpers in Java 8/11. Way cleaner than the legacy `FileReader` + `BufferedReader` ceremony for small/medium files.

1h ago 0

SQL

ARRAY_AGG and JSON_AGG (PostgreSQL)

Roll up grouped rows into a PostgreSQL array or JSON array — often a faster replacement for the application doing the same "group children under parent" join.

1h ago 0

HTML

Open Graph + Twitter Card Tags

How your page renders when shared to Facebook, LinkedIn, Slack, Discord, X. Every public page needs these — they dramatically improve click-through on shares.

1h ago 0

Kotlin

Channel — Coroutine Communication

A `Channel<T>` is a coroutine-safe queue — producer side sends, consumer side receives. Bounded buffer applies backpressure. Use Flow when broadcasting; use Channel for hand-off between coroutines.

1h ago 0

Rust

mpsc Channel Between Threads

`std::sync::mpsc` is the standard cross-thread channel. Multiple producers, single consumer. Send any `Send` type; the receiver blocks on `recv()` until something arrives.

1h ago 0

JavaScript

Create Element Helper

A concise helper for creating DOM elements with attributes, properties, styles, event listeners, and children in one call — similar to hyperscript or JSX without a build step. Eliminates repetitive createElement / setAttribute / appendChild chains and keeps DOM construction code readable.

1h ago 0

TypeScript

Typed Fetch Wrapper

A thin fetch wrapper that returns parsed JSON typed as `T`, throws on non-2xx, and accepts an AbortSignal. Single source of truth for "how this app talks to APIs."

1h ago 0

SQL

SELECT with WHERE / ORDER BY / LIMIT

The four-clause workhorse: pick columns, filter rows, sort them, return the top N. Standard across every database.

1h ago 0

Bash

Prune Dangling Docker Images

Reclaim disk space from Docker. `prune` operates on stopped containers, dangling images, build cache, and unused networks. Run periodically on CI runners.

1h ago 0

Bash

Tail Logs from Multiple Containers

`docker compose logs -f` already does this — but the one-liner with --tail and filters is the more useful day-to-day workflow when you only care about recent activity from a subset of services.

1h ago 0

Go

errors.Join — Aggregate Multiple Errors

Go 1.20+ ships `errors.Join`, which combines multiple errors into one. Stop accumulating errors in a slice and stringifying yourself — use the standard library.

1h ago 0

Kotlin

select — Choose Among Channels

`select { }` lets a coroutine wait on multiple suspending operations and proceed when the first one is ready — like nginx select() but for channels, deferreds, and timers.

1h ago 0

Kotlin

Type-Safe Builder DSL

`@DslMarker` + lambdas with receivers let you build statically-typed DSLs that look like declarative configuration. The HTML / Gradle Kotlin DSL style.

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Kotlin

tailrec — Tail-Call Optimization

Mark a recursive function `tailrec` and the compiler rewrites it as a loop — no stack frame per call, no StackOverflowError on deep recursion. Function must end with itself as the FINAL expression.

1h ago 0

Bash

Background Jobs + wait

Run several commands in parallel with `&`, then wait for all of them with `wait`. Collect exit codes via $! and check after wait returns.

1h ago 0

Bash

Generate UUID

Several portable ways to mint a v4 UUID from the shell — useful for request IDs, idempotency keys, temporary filenames.

1h ago 0

Go

select — Multiplex Channel Operations

`select` is like a switch for channels — runs whichever case is ready. Use `default` for non-blocking sends/receives; `case <-time.After(d)` for timeouts.

1h ago 0

Go

filepath.Walk — Recursive Tree Walk

`filepath.WalkDir` (Go 1.16+) is the modern, faster version. Visit every file/dir under a root; the callback decides whether to skip or process.

1h ago 0

Go

CSV Read/Write with encoding/csv

`encoding/csv` parses RFC 4180 CSVs. Read row-by-row with `Read()` or all at once with `ReadAll()`. Same for writing — flush with `Writer.Flush()` before closing.

1h ago 0

Kotlin

JSON Annotations — Rename, Default, Optional

Per-field annotations let you map Kotlin camelCase ↔ JSON snake_case, set defaults for missing fields, and skip nulls.

1h ago 0

Rust

From / Into Conversions

Implement `From` and you get `Into` for free. Then `.into()` and `T::from(x)` both work. The single most idiomatic way to express type conversions in Rust.

1h ago 0

HTML

HTML5 Document Boilerplate

Sensible HTML5 starting template: UTF-8 charset, responsive viewport, language attribute, semantic landmarks. Drop this in every new project before adding anything else.

1h ago 0

Bash

Recursive Directory Walker with Predicate

Use `find -print0` + `read -d ""` to safely iterate filenames that may contain spaces, newlines, or quotes. Standard bash for-loop over `find` output breaks on these.

1h ago 0

Bash

Check Command Exists Before Using It

`command -v` is the portable, fast way to check whether a binary is on $PATH. Avoid `which` (its behavior varies between systems).

1h ago 0

Bash

Count Occurrences of a Pattern

Several ways to count matches: lines containing X, total matches across a file, matches grouped by capture, etc.

1h ago 0

Bash

Filter Lines by Regex

grep -E (extended regex) is the right tool 95% of the time. Combine -i (case-insensitive), -v (invert), -n (line numbers), -B/-A (context lines).

1h ago 0

Go

Type Switches

When you have an `interface{}` (or any) and need to dispatch on its underlying type, use `switch v := x.(type)`. Cleaner than a chain of type-assertions.

1h ago 0

Go

iota — Auto-Incrementing Constants (Enums)

Go has no `enum` keyword but `iota` inside a const block gives you the same effect. Each line is the previous expression with iota auto-incremented.

1h ago 0

Kotlin

Jetpack Compose — Basic Composable

Compose is Android's modern declarative UI toolkit. A `@Composable` function describes UI; the runtime re-runs it when inputs change. Replaces XML layouts entirely.

1h ago 0