XC_VM/.github/instructions/bash-scripts.instructions.md

description, applyTo

description	applyTo
Use when writing or editing shell scripts in tools/, src/bin/, or src/infrastructure/. Covers bash conventions for XC_VM.	**/*.sh

Bash Script Conventions — XC_VM

Required Header

#!/bin/bash
set -euo pipefail

Style

• Indent with 4 spaces (not tabs — unlike PHP)
• Quote all variables: "$var" not $var
• Use [[ ]] for conditionals, not [ ]
• Use $() for command substitution, not backticks

Error Handling

• set -e — exit on first error
• set -u — treat unset variables as error
• set -o pipefail — catch errors in pipes
• Use trap for cleanup on exit when creating temp files

Security

• Never pass secrets via command-line arguments (visible in ps)
• Use environment variables or files with restricted permissions (0600)
• Validate external input before using in commands
• Avoid eval unless absolutely necessary

Paths

• Use absolute paths for system binaries: /usr/bin/php8.2, /usr/sbin/nginx
• Reference project root via variable, not hardcoded paths