A simple bash script to check if the default branch is main or master for a given repo

git-default-branch.sh

#!/bin/bash

# Check if the remote 'origin' has a 'main' branch
if git show-branch remotes/origin/main > /dev/null 2>&1; then
  echo "main"
else
  echo "master"
fi


# 1. Save this file somewhere in your $PATH
# 2. Add to your ~/.gitconfig the following
#
# [alias]
#   default-branch = !"git-default-branch.sh"

It is imperfect, but good enuf for my use cases :)