updatego.sh

#!/usr/bin/env bash

set -u

: "${PREFIX:=/usr/local}"

PATH="${PREFIX}/go/bin:${PATH}"

if ! command -v jq > /dev/null; then
	echo "Installing jq" >&2
	sudo apt-get install -y jq || exit 1
fi

checkLocal() {
	if command -v go > /dev/null; then
		if [ "$(go version | awk '{ print $3 }')" = "go${VERSION}" ]; then
			go version
			exit 0
		fi
	fi
}

if [ -v VERSION ]; then
	checkLocal
fi

set -e

tmp="$(mktemp -d)"

cleanup() {
	rm -rf "${tmp}"
}

trap 'cleanup' EXIT

data="$(curl -fsSL https://go.dev/dl/?mode=json)"

: "${ARCH="$(dpkg-architecture -q DEB_BUILD_ARCH)"}"
: "${VERSION="$(jq -r --arg arch ${ARCH} '.[0].files | map(select( (.os == "linux") and (.arch == $arch) ))[0].version' <<<${data})"}"
VERSION="${VERSION#go}"

checkLocal

: "${SHA256SUM=$(jq -r --arg arch ${ARCH} --arg ver go${VERSION} '.[] | select(.version==$ver) | .files[] | select((.arch==$arch) and (.os=="linux")) | .sha256' <<<"${data}")}"

cd "${tmp}"
curl -SLf https://go.dev/dl/go${VERSION}.linux-${ARCH}.tar.gz > go.tar.gz
echo "${SHA256SUM} go.tar.gz" > go.tar.gz.sha256sum
cat go.tar.gz.sha256sum | sha256sum -c --quiet

sudo rm -rf ${PREFIX}/go
sudo tar -C ${PREFIX} -zxf go.tar.gz

go version