Update go version

update-go.sh

  #!/bin/bash

case $1 in
    -h | --help ) echo "usage: $(basename $0) VERSION"; exit;;
esac

if [ $# -ne 1 ]; then
    1>&2 echo "error: wrong number of arguments"
    exit 1
fi

cur=$(go version | awk '{print substr($3, 3)}')
version=$1
echo "updating go to version ${version} (current: ${cur})"

base=go${version}.linux-amd64.tar.gz
url=https://dl.google.com/go/${base}
file=${HOME}/Downloads/${base}
dest=/opt/go${version}

set -e
set -x
echo downloading ${url}
curl -o ${file} ${url}

echo unpacking
rm -fr /tmp/go
tar xz -C /tmp -f ${file}

echo copy and symlink
sudo mv /tmp/go ${dest}
sudo ln -sfn ${dest} /opt/go