linux

name	linux
description	Linux environment conventions: shell idioms, systemd, package management, file permissions, and path conventions for this repo.
user-invocable	false
allowed-tools	["Bash(ls *)","Bash(systemctl *)","Bash(journalctl *)","Bash(apt *)","Bash(apt-get *)","Bash(dpkg *)","Bash(dnf *)","Bash(rpm *)"]

Linux Environment Guide

This repo runs on Linux. Apply these conventions.

Shell

• Use bash unless the script explicitly declares another shell.
• Prefer #!/usr/bin/env bash over hardcoded /bin/bash.
• Quote all variable expansions: "$VAR", not $VAR.
• Use set -euo pipefail in scripts that must not silently fail.

Paths

• Home: $HOME or ~ — never hardcode /home/user.
• Config: $XDG_CONFIG_HOME (default ~/.config) for user-scoped settings.
• Data: $XDG_DATA_HOME (default ~/.local/share).
• Binaries: check /usr/local/bin before /usr/bin; install to /usr/local/bin for local installs.

Packages

• Prefer the system package manager (apt/dnf/pacman) for system-level installs.
• Use apt-get in scripts; apt in interactive sessions.
• Pin versions in install scripts to avoid silent drift: apt-get install -y pkg=version.

Services

• Check service status: systemctl status <service>
• View logs: journalctl -u <service> -n 50 --no-pager
• Never restart a service without checking whether it is in production use first.

File Permissions

• Scripts must be executable: chmod +x script.sh
• Config files with secrets: chmod 600; directories containing them: chmod 700.
• Avoid chmod 777 — use group permissions instead.

Processes

• ps aux | grep <name> to confirm a process is running.
• kill -0 <pid> to check if a PID exists without sending a signal.
• Prefer pkill -f pattern over guessing PIDs.