Bash
getopts in Bash: Parse Command-Line Options Properly
A tested getopts skeleton for Bash scripts: flags, options with values, required options, error handling, and a manual loop for --long options.
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Web
Docket Cache: A WordPress Object Cache Without Redis
A persistent WordPress object cache for hosting without Redis: each entry is a PHP file that OPcache keeps compiled. How it works, and what it did on a test site.
MySQL
Match an IPv4 Address Against a CIDR Subnet in MySQL
Store IPv4 addresses as INT UNSIGNED and test CIDR membership with a bitmask or, much faster on a big table, an indexed BETWEEN range on network and broadcast.
Bash
Bash Strict Mode: What set -euo pipefail Really Does
set -euo pipefail is good advice, but each option has rules about when it fires. Here is what each one does and the cases that surprise people.
Bash
Read a File Line by Line in Bash (the Right Way)
while IFS= read -r line is the correct loop, but the last line, pipes, commands that read stdin and Windows line endings each have a trap. Here they are, tested.
Bash
str_pad() in Bash: Pad a String to a Fixed Length
PHP-compatible str_pad() in pure Bash, when printf "%-10s" and %05d are enough, and why multibyte text breaks the alignment of your columns.
Bash
in_array() in Bash: Check if an Array Contains a Value
A correct in_array() for Bash, an associative-array set for many lookups, and a demonstration of why [[ "${arr[*]}" =~ value ]] gives false positives.
Programming
Debounce vs Throttle in JavaScript, With a Timeline Demo
Two small functions that stop search boxes and scroll handlers from running too often, with a runnable timeline that shows exactly when each one fires.
Bash
explode() and implode() in Bash: Split and Join Strings
PHP's explode() and implode() in Bash: read -ra and mapfile -d for splitting, "${arr[*]}" for joining, and functions that cope with multi-character delimiters.
Web
nginx as a Reverse Proxy: Headers, WebSockets and Timeouts
What the backend really receives behind nginx: proxy_pass URI rewriting, Host and X-Forwarded headers, WebSocket upgrades, 504s from timeouts, and streaming.