Download and install golang version into /opt/go folder. Supports version managing though alternatives command.

install-go.sh

#!/bin/env bash

set -e

DOWNLOAD_URL='https://go.dev/dl/go1.25.1.linux-amd64.tar.gz'

# goM.mm.ff.linux-amd64.tar.gz
GOLANG_TAR_GZ="$(basename $DOWNLOAD_URL)"
# goM.mm.ff.linux-amd64
GOLANG="$(basename $GOLANG_TAR_GZ .tar.gz)"
# M.mm.ff
VERSION=$(echo $GOLANG | sed -E 's/go([[:digit:]]+\.[[:digit:]]+\.[[:digit:]]+)\..*/\1/')
# Mmmmfff
PRIORITY=$(printf '%d%03d%03d' $(echo $VERSION | tr '.' ' '))

INSTALL_BASE_FOLDER='/opt/go'

cat <<ENDL
Go Download URL:       $DOWNLOAD_URL
Go Version:            $VERSION
Install folder:        $INSTALL_BASE_FOLDER/$GOLANG
alternatives priority: $PRIORITY

ENDL

####################################################

if [ -d "$INSTALL_BASE_FOLDER/$GOLANG" ]; then
	echo "[ERROR] Oh, $INSTALL_BASE_FOLDER/$GOLANG seems to be already installed!"
	exit 1
fi

if [[ "$EUID" != 0 ]]; then
	echo '[ERROR] Please, run this script as root!'
	exit 1
fi

####################################################

cleanup() {
	local exit_code=$?

	if [[ $exit_code != 0 ]]; then
		rm -rf "$INSTALL_BASE_FOLDER/$GOLANG"
		echo "[INFO] Temporary files preserved at $TMP_DIR"
		exit $exit_code
	fi

	rm -rf "$TMP_DIR"
}

trap cleanup EXIT

####################################################

TMP_DIR="$(mktemp -d)"

mkdir -p "$INSTALL_BASE_FOLDER/$GOLANG"

cd $TMP_DIR
curl -L "$DOWNLOAD_URL" -o "$GOLANG_TAR_GZ"

tar xf "$GOLANG_TAR_GZ"
mv go "$GOLANG"

mv "$GOLANG" "$INSTALL_BASE_FOLDER"

alternatives \
	--install /usr/bin/go golang "$INSTALL_BASE_FOLDER/$GOLANG/bin/go" "$PRIORITY" \
	--follower /usr/bin/gofmt gofmt "$INSTALL_BASE_FOLDER/$GOLANG/bin/gofmt"

####################################################

echo
echo '> go version'
go version