command-execution-principles

name	command-execution-principles
description	Safe command execution: input sanitization, timeout handling, output capture, error propagation. For spawning processes, shell commands, system calls.
user-invocable	false

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