Git pre-commit hook is not running on Windows
I'm just starting to look into Git hooks, but I can't seem to get them to run.
I set up a local repository, so there is now a '.git' directory in my project folder. I have added a '.cmd' file into the C:/path/to/my/project/.git/hooks directory named 'pre-commit.cmd'. Here is the contents of this file:
echo "HOOK RUNNING"
echo. 2>C:/path/to/my/project/.git/hooks/EmptyFile.txt
This should echo the text "HOOK RUNNING" and create an empty text file in that directory. However, if I commit changes through my IDE (NetBeans) or use Git Bash to commit, neither of them seem to run my pre-commit hook, as no file is created.
My understanding is that all you have to do to get a hook to run is add an executable with the name of the hook (as I have done). Am I doing something wrong?
Note: This is on a Windows 7 PC.
Name your hook pre-commit
(without any file extension).
And add #!/bin/sh
on the first line or #!/bin/bash
.
You probably don't have the permissions to run the pre-commit
file
Run in your terminal:
chmod +x .git/hooks/pre-commit
Thanks to @vaughan for giving the idea
TL;DR
Git hooks work on Git for Windows by default assuming the Git hook script is simple.
Background of Git and Windows
Please Note: Git was made for shell interpretation; thus, using Git hooks on a Windows command prompt or Windows-made PowerShell will inherently have its flaws, and complete interoperability is not to be expected.
Using Git hooks on Windows is possible, but it has many drawbacks.
Git for Windows uses a shell emulator that makes Bash and shell commands possible. This means that when a Git hook is activated by Git, the Windows version will run the command using the shell emulator. Which in turn, will convert those shell commands to commands that the Windows operating system can understand. Meaning, simple shell scripts will work right off the bat. For example, the Git hook pre-commit
that ships with an initialization of a Git repository can be run without any modification.
Example of default behavior
-
Initialize a Git repository with the command
git init
-
Navigate to the Git hooks directory with the command
cd .git\hooks
-
This directory holds all the Git hook scripts. Create a file named
pre-commit
. Note:The name of the file is important
-
Replace the contents with the following shell script
#!/bin/sh echo "Hello, World!"
-
Navigate back to your root directory of the project and create a file named
test.txt
using the commandecho "something" > text.txt
-
Stage the file to commit using the command
git add test.txt
-
Commit the change and watch the pre-commit hook activate using the command
git commit -m "test commit"
-
Verify the output to look like the following
git commit -m "test commit" Hello, World! [master f00ccea] test commit
Example of bad behavior
When using a very advanced shell script to do things in Git hooks, Windows shell interpretation doesn't always stack up. For example, when using the Husky Git hook plugin for NPM, along with the Prettier formatter, the commands do not map 1-1. Meaning that your pre-commit Git hook will fail on Windows.
Answering user1578653's question
A Git hook is an executable script; however, you are using a command prompt script (.cmd
) and not a shell script (.sh
). If you would like this behavior you described on a Windows operating system then create the file named pre-commit
and place it in the .git\hooks
directory (relative to the project you are working on). Then place the following content in that file.
.git\hooks\pre-commit
#!/bin/sh
echo "HOOK RUNNING"
thisCausesError 2> .git/hooks/EmptyFile.txt
You will notice that the Git hook works and outputs the words HOOK RUNNING
to the console, and the thisCauseError
will print an error message to standard error that will be printed to the file EmptyFile.txt
.
In my case, I had set core.hooksPath
to the wrong directory.
Resetting it with git config --global core.hooksPath '~/.githooks'
solved the issue :)
You can verify your hooks path using git config --get core.hooksPath