An example git hook which shows how to append an arbitrary bit of information to a commit

prepare-commit-msg

#!/bin/sh
#
# An example git hook which shows how to append an arbitrary bit of information to a commit.
# The following appends some version number to a commit message.
#

VERSION=$(command --version) # `command` is any executable
BUILD="Xrayez" # Some arbitrary name

# Ensure that version contains some build name
if [[ $VERSION = *"$BUILD"* ]]; then
    # Append only if not already present in the commit message
    grep -qs $BUILD "$1" || printf "\n$VERSION" >> "$1"
else
    # Build name is not configured
    exit -1
fi