git hook

Small porcelain over the .git/hooks dir.

🎯 What & why

Thin porcelain over the .git/hooks directory: lists, runs, and otherwise pokes the repo's hook scripts. Useful when you want to invoke a hook manually instead of waiting for git to fire it.

🧠 Mental model

Hooks are just executable files in .git/hooks/ (or wherever core.hooksPath points). Git runs them at well-defined moments; git hook run is the manual trigger.

🛠️ Synopsis

git hook run [--ignore-missing] [--to-stdin=<path>] <hook-name> [-- <hook-args>]

# Hooks live in:
.git/hooks/<name>            # default location
$(git config core.hooksPath) # override (team-shared hooks dir)

# Common hooks (chmod +x to enable):
pre-commit, prepare-commit-msg, commit-msg, post-commit
pre-push, pre-rebase, post-checkout, post-merge
pre-receive, update, post-receive, post-update  (server side)

🎚️ Switches & options

Flag	What it does
`run <name>`	Execute the named hook as if git triggered it
`--ignore-missing`	Exit 0 if the hook isn't installed instead of erroring
`--to-stdin=<file>`	Pipe file contents to the hook's stdin
`-- <args>`	Pass remaining args to the hook
`chmod -x .git/hooks/X`	⚠️ Disabling a hook by removing the +x bit; trivially reversible but easy to forget

📦 Subcommands

run — Run a named hook with the same env git would set up

git hook run pre-commit

💡 Use cases

Debug a flaky pre-commit script without making a dummy commit.
Wire CI to run the same pre-push hook the developers run.
Test a commit-msg hook by piping a draft message via --to-stdin.
Verify a shared hooks directory (core.hooksPath) is wired up correctly.

🧪 Examples

Run the pre-commit hook now

git hook run pre-commit

Test commit-msg with a draft message

git hook run --to-stdin=draft.txt commit-msg draft.txt

Skip silently if hook missing

git hook run --ignore-missing pre-push

Point repo at a shared hooks dir

git config core.hooksPath .githooks

🎓 Recommendations

Check hooks into a tracked dir (e.g. .githooks/) and set core.hooksPath; .git/hooks/ isn't versioned.
Always chmod +x your hooks; a non-executable hook is silently ignored.
Use git hook run in CI to dogfood the same checks devs run locally.

🪤 Common pitfalls

Sample hooks ship as *.sample and are inactive; rename them to enable.
On Windows, hook shebangs need a working interpreter on PATH; bash hooks fail under cmd.exe.
core.hooksPath overrides .git/hooks/ entirely - the old hooks stop firing without warning.

🔗 Related modules

📝 Quiz

Hit each option, then Check answers. Score is recorded; Next is always open.