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
Bash
Format Date Like a Pro
`date` accepts a format string + optional override of the date being formatted. The +%FT%TZ form gives you ISO-8601 / RFC-3339 in one call.
@admin
PHP
Validate Email (RFC-aware)
Use PHP's built-in FILTER_VALIDATE_EMAIL with the FILTER_FLAG_EMAIL_UNICODE flag for IDN domains, plus a length sanity check. Trust this over hand-rolled regex.
PHP
Convert Timestamp to User Timezone
Convert a stored UTC timestamp into the viewer's timezone for display. Round-trip safe: re-converting to UTC always gives back the original timestamp.
PHP
Human-Readable File Size
Format a byte count as a human-friendly string (KB / MB / GB / TB). Defaults to base-1024 sizes; pass base 1000 for SI units.
Go
SHA-256 Hash of File or String
`crypto/sha256` is the canonical hash. Use the streaming `Hash` interface for files — never load multi-GB content into memory just to hash it.
Go
context.WithValue — Request-Scoped Values
Attach data to a context that flows down through your call chain — request IDs, authenticated user, trace spans. Use a private key type to avoid collisions across packages.
Java
flatMap — Flatten Nested Streams
Map each element to a Stream, then concatenate all of them into one. Used everywhere from "all words from a list of sentences" to "all permissions from a list of roles".
Java
HttpClient — Synchronous GET (Java 11+)
`java.net.http.HttpClient` ships in the JDK — no Apache HttpClient or OkHttp needed for most cases. Reuse one client across the app; configure timeouts and follow-redirects up front.
Kotlin
Sequences — Lazy Collections
A `List` materializes every intermediate `map`/`filter` result. A `Sequence` processes ONE element through the whole pipeline at a time — better for big inputs or short-circuiting (`first`, `take`).
SQL
BETWEEN — Range Filtering
`BETWEEN a AND b` is inclusive on both ends. Cleaner than `col >= a AND col <= b`. For dates, watch for end-of-day vs midnight boundaries.
SQL
LEFT JOIN — Keep Unmatched Left Rows
Returns every row from the LEFT side, NULL-filled where the right side doesn't match. The standard pattern for "this entity and its optional children".
Go
HTTP Middleware (Decorator Pattern)
Middleware in Go is `func(http.Handler) http.Handler`. Wrap a handler with logging, auth, recovery, CORS, or rate limiting — chain them together for a real middleware stack.
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
RGB ↔ Hex Conversion
Two-way conversion between #RRGGBB hex strings and [R, G, B] arrays. Handy when working with theme colors that come from both sources (CSS strings vs. RGB sliders).
Rust
tokio mpsc Channel
Async multi-producer / single-consumer channel. Producers `.send()`, the single receiver `.recv().await` items as they arrive. Bounded — the channel back-pressures producers when full.
Bash
Substring + Find/Replace (parameter expansion)
Bash's ${var:offset:length} and ${var//pattern/replacement} let you do most string operations without ever spawning sed. Faster, and the syntax is portable across modern shells.
PHP
JSON Structured Logger
Append a single JSON object per line to a log file. Easy to grep and to ship into Datadog / Loki / CloudWatch later without re-parsing.