How to install the GitHub CLI in terminal without Homebrew

gh-update.sh

#!/bin/bash

echo "This will install the GitHub CLI (gh) onto your system"
echo "When this is done, you'll have a new 'gh' command line tool..."
echo "in your /usr/local/bin directory. On most Mac and Linux systems..."
echo "That directory will be in your 'PATH' environment variable..."
echo "If it isn't, please add it. You can temporarily do so by running this:"
echo "\n export PATH=\"/usr/local/bin:\$PATH\""

RELEASE=$1

curl -o gh.tgz -L https://github.com/cli/cli/releases/download/v${RELEASE}/gh_${RELEASE}_macOS_amd64.tar.gz
tar -xzf gh.tgz
cp gh_${RELEASE}_macOS_amd64/bin/gh /usr/local/bin/gh
rm gh.tgz
rm -r ./gh_${RELEASE}_macOS_amd64