Writing a proper git message is a good coding practice. A good commit message should clearly convey what has been changed and why it has been changed. Sometimes developers use an improper message in a hurry to commit and push the changes.

To avoid such situations, we can use git hooks.

Git hooks are shell scripts placed in .git/hooks directory of a repository. These shell scripts are executed in response to specific git events like commit messages, pushing to the repository, etc.

Here is a working hook that enforces the developer to use a commit message of 30 characters.

Please create a new file with the name commit-msg in .git/hooks directory of your repository. Copy and paste the below content into it.

Make this script executable using the command chmod 777 commit-msg.

#!/usr/bin/env bash

# Hook to make sure that no commit message line is less than 30 characters

while read line; do
    # Skip comments
    if [ "${line:0:1}" == "#" ]; then
        continue
    fi
    if [ ${#line} -le 30 ]; then
        echo "Commit messages must be atleast 30 characters."
        echo "The following commit message has ${#line} characters."
        echo "${line}"
        exit 1
    fi
done < "${1}"

#
# Automatically adds branch name to every commit message.
#
NAME=$(git branch | grep '*' | sed 's/* //')
echo "[$NAME]" $(cat "$1") > "$1" 

#!/usr/bin/env bash

# Hook to make sure that no commit message line is less than 30 characters

while read line; do
    # Skip comments
    if [ "${line:0:1}" == "#" ]; then
        continue
    fi
    if [ ${#line} -le 30 ]; then
        echo "Commit messages must be atleast 30 characters."
        echo "The following commit message has ${#line} characters."
        echo "${line}"
        exit 1
    fi
done < "${1}"


#
# Automatically adds branch name to every commit message.
#
NAME=$(git branch | grep '*' | sed 's/* //')
echo "[$NAME]" $(cat "$1") > "$1"

exit 0