Skip to content
C3P

c3p hook

c3p hook install|uninstall manages the project’s git pre-commit hook. The hook script is fixed and minimal, and is fail-open — a missing or broken c3p binary never blocks a commit. Its only job is to surface a warning if you’re about to commit drifted .claude/ files.

Help

Section titled “Help”
c3p hook — manage the git pre-commit hook


USAGE
  c3p hook install|uninstall [options]


DESCRIPTION
  The hook script content is fixed and minimal (R25a) and fail-open: a
  missing or broken c3p binary never blocks commits.


  install:    writes .git/hooks/pre-commit (preserves existing hook unless --force)
  uninstall:  removes the hook only if its content matches the canonical
              script (a user-edited or third-party hook is left untouched)


OPTIONS
  --force            (install only) overwrite an existing pre-commit hook


GLOBAL OPTIONS
  --cwd=<path>     project root (default: cwd)
  --json           machine-readable output (silences human output)
  --quiet, -q      silence human output (preserves errors + exit codes); incompatible with --json


EXAMPLES
  c3p hook install
  c3p hook install --force
  c3p hook uninstall
  c3p hook install --json


EXIT CODES
  0  success (or no-op if hook is already in the desired state)
  1  bad argv (missing install|uninstall, install with conflicting hook + no --force)
  2  IO/permission fault, missing .git/ directory

Example

Section titled “Example”
Terminal window
# Install (or no-op if already installed)
c3p hook install


# Replace an existing hook with the canonical c3p one
c3p hook install --force


# Remove the hook (only if it's the canonical script — user-edited hooks left alone)
c3p hook uninstall

Windows: pre-commit.bat companion

Section titled “Windows: pre-commit.bat companion”

When you run c3p hook install on Windows, c3p writes both files into the hooks directory:

  • pre-commit — the same POSIX shell script installed on Linux/macOS
  • pre-commit.bat — a native cmd companion with the same fail-open behavior

Both are managed (install/uninstall) symmetrically: install writes both, and uninstall removes both only if their bytes match the canonical content. A user-edited pre-commit.bat is left alone, mirroring the POSIX rule.

Which hook does git actually run?

Section titled “Which hook does git actually run?”

Git for Windows installations vary, and core.hooksPath is the authoritative answer:

  • Default install (no core.hooksPath set): git looks for .git/hooks/pre-commit and runs it through the bundled MSYS2 sh.exe. The POSIX script wins.
  • Custom core.hooksPath pointing at a directory whose pre-commit.bat resolves before pre-commit (per the user’s PATHEXT and shell): the .bat runs instead.
  • IDE-bundled git (some Windows editors): may invoke the .bat directly, bypassing sh.exe entirely.

You can override either side without touching c3p — the bytes are pinned and both code paths share the same fail-open contract, so either choice keeps the “drift warning, never block a commit” guarantee.

Verifying which one git uses

Section titled “Verifying which one git uses”
Terminal window
git config --get core.hooksPath
git -C <repo> rev-parse --git-path hooks

c3p always writes to .git/hooks/ (the conventional location). If you’ve set core.hooksPath to point elsewhere, git will read from your custom path and not see c3p’s hooks — you’ll need to copy or symlink the files into your core.hooksPath directory yourself, or unset core.hooksPath to use c3p’s managed hooks. Either way, the bytes are pinned and the same fail-open contract applies wherever the file lands.

To disable one of the two, delete it. Re-running c3p hook install restores both. Uninstall removes c3p’s managed copy in either direction.

See also

Section titled “See also”