Like many other Version Control Systems, Git has a way to fire off custom scripts when certain important actions occur. There are two groups of these hooks: client-side and server-side. Client-side hooks are triggered by operations such as committing and merging, while server-side hooks run on network operations such as receiving pushed commits. You can use these hooks for all sorts of reasons.
The hooks are all stored in the hooks sub directory of the Git directory. In most projects, that’s .git/hooks.
To enable a hook script, put a file in the hooks subdirectory of your .git directory that is named appropriately (without any extension) and is executable.
pre-push script is called by git push after it has checked the remote status, but before anything has been pushed. If this script exits with a non-zero status nothing will be pushed.
This hook is called with the following parameters:
$1 -- Name of the remote to which the push is being done (Ex: origin)
$2 -- URL to which the push is being done (Ex: https://<host>:<port>/<username>/<project_name>.git)
Information about the commits which are being pushed is supplied as lines to the standard input in the form:
<local_ref> <local_sha1> <remote_ref> <remote_sha1>
Sample values:
local_ref = refs/heads/master
local_sha1 = 68a07ee4f6af8271dc40caae6cc23f283122ed11
remote_ref = refs/heads/master
remote_sha1 = efd4d512f34b11e3cf5c12433bbedd4b1532716f
Below example pre-push script was taken from default pre-push.sample which was automatically created when a new repository is initialized with git init
# This sample shows how to prevent push of commits where the log message starts
# with "WIP" (work in progress).
remote="$1"
url="$2"
z40=0000000000000000000000000000000000000000
while read local_ref local_sha remote_ref remote_sha
do
if [ "$local_sha" = $z40 ]
then
# Handle delete
:
else
if [ "$remote_sha" = $z40 ]
then
# New branch, examine all commits
range="$local_sha"
else
# Update to existing branch, examine new commits
range="$remote_sha..$local_sha"
fi
# Check for WIP commit
commit=`git rev-list -n 1 --grep '^WIP' "$range"`
if [ -n "$commit" ]
then
echo >&2 "Found WIP commit in $local_ref, not pushing"
exit 1
fi
fi
done
exit 0