A shell script for switching Go versions.

switchgo.sh

#!/bin/sh

set -e

if [[ "$#" -ne 1 ]]; then
	echo "Usage: switchgo version" >&2
	exit 2
fi
if [[ -z "${GOBIN}" ]]; then
	echo "GOBIN is not set" >&2
	exit 2
fi

if ! command -v "${GOBIN}/go${1}" &> /dev/null; then
	echo "Go $1 doesn't exist, start downloading..."
	if [[ "$(go version | cut -d " " -f 3 | cut -d . -f 2)" -ge 17 ]]; then
		go install "golang.org/dl/go${1}@latest"
	else
		go get "golang.org/dl/go${1}"
	fi
	"${GOBIN}/go${1}" download
fi

ln -sf "$(command -v "${GOBIN}/go${1}")" "${GOBIN}/go"
echo "Switched to Go $1"