command-execution-principles

## Command Execution Principles ### Security - ❌ `exec(userInput)`, `shell("rm " + userFile)` - ✅ Argument lists (no shell string concat), validate/sanitize all args - Never run as root/admin without explicit human approval. Elevated perms required → STOP and request auth. - Least-privilege service accounts ### Portability - Use language stdlib over shell commands (file I/O APIs instead of cat/cp/mv) - Test on all target OS (path joining functions, not / concatenation) ### Error Handling - Check exit codes (non-zero = failure) - Capture + log stderr - Set timeouts for long-running - Handle "command not found" gracefully ### Checklist - [ ] User input sanitized before commands - [ ] Arguments as lists (no shell concat) - [ ] Minimum permissions - [ ] Exit codes checked - [ ] Timeouts set - [ ] stderr captured + logged ### Related - Security Mandate @.gemini/rules/security-mandate.md - Security Principles @.gemini/rules/security-principles.md