Tools: Macos's Little-known Command-line Sandboxing Tool (2025) 2026

sandbox-exec is a built-in macOS command-line utility that enables users to execute applications within a sandboxed environment. In essence, it creates a secure, isolated space where applications can run with limited access to system resources – only accessing what you explicitly permit.

The concept behind sandboxing is fundamental to modern security: by restricting what an application can access, you minimize the potential damage from malicious code or unintended behavior. Think of it as putting an application in a secure room where it can only interact with specific objects you've placed there.

Before diving into usage, let's understand why sandboxing matters:

Protection from malicious code: If you're testing an unfamiliar application or script, sandboxing can prevent it from accessing sensitive files or sending data across the network.

Damage limitation: Even trusted applications can have vulnerabilities. Sandboxing limits the potential impact if an application is compromised.

Testing environment: Developers can test how applications function with limited permissions before implementing formal App Sandbox entitlements.

Resource restriction: Beyond security, sandboxing can limit an application's resource consumption or network access.

Using sandbox-exec requires creating a sandbox profile (configuration file) that defines the rules for your secure environment. The basic syntax is:

Where profile.sb contains the rules defining what the sandboxed application can and cannot do, and command_to_run is the application you want to run within those constraints.

Sandbox profiles use a Scheme-like syntax (a LISP dialect) with parentheses grouping expressions. The basic structure includes:

Source: HackerNews