rename-master-to-main.sh

#!/bin/sh

# usage:
#   $ export GITHUB_TOKEN=[token]
#   $ rename-master-to-main.sh [org] [repo] 
#   generate GITHUB_TOKEN at https://github.com/settings/tokens/new with "repo" privileges

ORG="$1"
REPO="$2"
rm -rf $REPO
git clone git@github.com:$ORG/$REPO.git
cd $REPO

# 1. make sure master exists and main does not # XXX fail if not true
MASTER=`git branch --list master`
MAIN=`git branch --list main`
if [ -z "$MASTER" ]; then
  echo "The 'master' branch does not exist, exiting"
  exit 1
fi
if [ ! -z "$MAIN" ]; then
  echo "The 'main' branch already exists, exiting"
  exit 1
fi

git switch master
git pull
if [ $? -gt 0 ]; then
  echo "Problems pulling changes from 'master' branch, exiting"
  exit 1
fi

git branch -m master main
git symbolic-ref --short refs/heads/master refs/heads/main
git push origin main
if [ $? -gt 0 ]; then
  echo "Problems pushing changes to 'main' branch, exiting"
  exit 1
fi

JSON="{\"name\":\"$REPO\", \"default_branch\":\"main\"}"
TOKEN="token $GITHUB_TOKEN"
curl -X PATCH -H "Content-Type: application/json" -H "Authorization: $TOKEN" -d "$JSON" https://api.github.com/repos/$ORG/$REPO