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
cURL Multipart File Upload
Upload one or more files via multipart/form-data using cURL's CURLFile abstraction. No manual boundary or body construction needed.
@admin
SQL
CASE WHEN — Conditional Values
Inline if/else inside a SELECT, ORDER BY, or aggregation. The Swiss-army knife for converting raw column values into labels or buckets.
Java
JUnit 5 — Basic Test
JUnit 5 is the modern standard. `@Test` marks a method as a test; `Assertions.*` provides the assertion API. `@BeforeEach` runs setup before every test.
HTML
Iframe with Sandbox + lazy loading
Embed third-party content (YouTube, Stripe, maps) safely. `sandbox` restricts what the embedded page can do. `loading="lazy"` defers offscreen iframes — huge perf win for blog posts with multiple embeds.
Kotlin
kotlin.time — Duration and measureTime
`kotlin.time.Duration` is a typesafe time amount with friendly literal syntax (`5.seconds`, `2.minutes`). `measureTime { }` benchmarks a block.
SQL
UPSERT — MySQL ON DUPLICATE KEY UPDATE
MySQL's flavor of upsert. Triggers when an INSERT would violate a PRIMARY KEY or UNIQUE constraint. Use `VALUES()` (or `NEW.col` in MySQL 8.0.20+) to reference the would-be-inserted row.
Bash
ANSI Color Output Helpers
Wrap printf with ANSI escape codes for color and bold. Auto-disable if stdout isn't a TTY (so piping to a file doesn't pollute it with escape sequences).
Go
json.RawMessage — Deferred Decoding
`json.RawMessage` is a `[]byte` that survives a decode pass. Use it for envelope-style JSON where one field's type depends on another (e.g. `{"type":"X","payload":{...}}`).
Go
sync.Pool — Reuse Allocations
`sync.Pool` keeps a pool of reusable objects to reduce allocator pressure in hot paths. Good for byte buffers, JSON encoders, or anything you allocate frequently and only need briefly.
Kotlin
reified Type Parameters
In an `inline` function, a `reified` type parameter survives erasure — you can use `T::class`, `is T`, `as T` at runtime. The killer use-case for JSON parsers ("give me a List<User>").
Java
Semaphore — Bounded Concurrency
Limit how many threads can enter a critical section. `acquire()` blocks until a permit is available; `release()` returns one. Use for rate limits, connection pools, or any "max N at a time" pattern.
Rust
Generic Function with Trait Bounds
Use `T: Trait` to require a capability on a generic parameter. The `where` clause is the more readable variant when bounds get long.
Kotlin
zip and zipWithIndex
`zip` pairs elements positionally; the result is the length of the shorter list. `withIndex()` gives you `(index, value)` pairs without the manual `forEachIndexed`.
PHP
Resize Image to Max Dimension
Shrink an uploaded image so its longest side is no more than $maxDim pixels, preserving aspect ratio. Re-encodes to JPEG at the given quality. Uses the GD extension.
Bash
Multipart File Upload via cURL
Upload one or more files using -F. Optional extra form fields go through the same flag — quote carefully to preserve spaces.
Python
Protocol — Structural (Duck) Typing
Define what an object can DO, not what it IS. A class doesn't need to inherit from a Protocol — it just needs to match the shape. Like TypeScript interfaces with `implements` optional.
SQL
MERGE — One Statement for INSERT + UPDATE + DELETE
`MERGE` (standard SQL, PostgreSQL 15+, SQL Server, Oracle) is a single statement that combines INSERT/UPDATE/DELETE driven by joining a source against a target. Heavy artillery for reconciliation jobs.