In this tutorial I won't focus on what git hooks
are, I'll show u simple example on how you can use them
What git hooks are?
From git documentation:
Hooks are programs you can place in a hooks directory to trigger actions at
certain points in git’s execution. Hooks that don’t have the executable bit set
are ignored.
and in other words:
- hook is program that run when event occurs
- there is a directory with all the hooks
All the event are listed here
In this tutorial I want to focus on Pre-Commit
event
Sample Hooks
In our .git/hooks
folder we can find all the default hook samples:
$ ls .git/hooks
applypatch-msg.sample post-update.sample pre-push.sample prepare-commit-msg.sample
commit-msg.sample pre-applypatch.sample pre-rebase.sample update.sample
fsmonitor-watchman.sample pre-commit.sample pre-receive.sample
Our Hook
In this 101 tutorial I'll show you how to create simple git hook
that prevent git commit
command to master
branch
Lets now create new file pre-commit
without any file extension
$ touch .git/hooks/pre-commit
Now because git
runs under linux (for windows using MinGW) the first line needs to be Shebang
For Linux:
#!/bin/bash
For Windows it should be you git bash location, For example:
#!C:/Program\ Files/Git/usr/bin/sh.exe
next we need to execute git branch
command in order to print our branch, but we want to know if we are currently on master
by using grep
:
git branch | grep "* master"
Now we warp with if
with message:
if git branch | grep "* master" > /dev/null 2>&1
then
cat <<\EOF
# Message
EOF
fi
in order to disable the commit we need to provide exit code which is not 0:
exit 1
And our hook for pre-commit
looks like that:
if git branch | grep "* master" > /dev/null 2>&1
then
cat <<\EOF
Commits are not allowed on branch Master!
EOF
exit 1
fi
lets try:
$ git commit -m "Commit message"
Commits are not allowed on branch Master!
Make it as Default
What is the problem with most people? is that we are lazy, we want to do something only once
and we have this option using git template directory
that you can find more about it here
what that this tempalte direcotry does is when you are using git init
command it will copy all the files under this directory whose name do not start with a dot
now lets define our template dir
:
$ export GIT_TEMPLATE_DIR=PATH
$ cd PATH
$ mkdir hooks
and under PATH\hooks
create your hooks and enjoy :)
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Top comments (2)
Well done!
I hope, in the future, you cover how to share hooks with other contributers, I mean tools like pre-commit or the others.
There are multiple ways, if you are using
Javascript
you can use Husky,else we are using
.githook
and redirectgit config core.hooksPath
to this folder,but it needs to be done for each member on his local repository, still couldn't find a way to make it automatically