shell-scripts

Installation
SKILL.md

Shell Scripts

Apply these rules whenever writing or reviewing shell script files.

Default target: maximum portability — scripts must work on GNU/Linux, BSDs (FreeBSD, OpenBSD, NetBSD), macOS, and BusyBox/Alpine without modification, unless the user explicitly restricts the target platform.

Cross-Platform Portability

Scripts must work on all of these without modification unless a target is explicitly narrowed:

Platform Shell Notes
GNU/Linux (glibc) dash or bash as sh GNU coreutils; date, sed, awk are GNU-flavored
Alpine / BusyBox ash Minimal builtins; no GNU extensions
macOS bash 3.2 or zsh as sh BSD coreutils; sed, date, stat differ from GNU
FreeBSD / OpenBSD / NetBSD sh (pdksh/ash variant) BSD coreutils; POSIX-strict

Coreutils gotchas

Related skills
Installs
3
First Seen
Mar 6, 2026