Exit code

A number that a script returns at the end to say how it went: 0 means “everything is fine”, 2 means (in hooks) “stop the action”.

You’ll also find it as: exit codes, exit 2

How it appears in the course

The script answers with a number (the exit code): 0 means “everything is fine”, 2 means “stop”.
Introduction · Module 07, Hooks: automatic actions
Every program returns a number when it finishes. That’s the exit code. It’s the program’s way of saying “everything is fine” or “stop”.
What does a hook receive, and what does it answer? · Module 07, Hooks: automatic actions
If the file name contains one of them, it writes a message on stderr (>&2) and exits with exit 2. That means “stop”. Claude gets the message and understands why it isn’t allowed.
Ready-to-use recipes · Module 07, Hooks: automatic actions

Where you learn it

In module 07 · Hooks: automatic actions, in the Claude Code for Beginners course.

Related terms

FormatterHookjqLockfilestderrstdin

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