gvm.sh

#!/usr/bin/env bash

set -e

usage()
{
    echo "GVM is a simple golang version manager written in bash."
    echo "$(basename $0) -v <version>"
}

while getopts ":v:h" opt; do
    case ${opt} in
        h)
            usage
            exit 0
            ;;
        v)
            WANTED=${OPTARG}
            ;;
    esac
done

if [[ -z ${WANTED} ]]; then
    usage
    exit 1
fi

if [[ ! -d ${HOME}/sdk/go${WANTED} ]]; then
    echo "Runtime not found. Installing..."
    go get golang.org/dl/go${WANTED}
    go${WANTED} download
fi

pushd ${HOME}/sdk > /dev/null
rm -f active
ln -s go${WANTED} active
popd > /dev/null

if [[ ${PATH} != *"${HOME}/sdk/active/bin"* ]]; then
    echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
    echo "Runtime set, add it to your path"
    echo "export PATH=\${PATH}:\${HOME}/sdk/active/bin"
    echo "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
fi

Simple usage:

[0]Pluto:~ $ go version
go version go1.12.6 linux/amd64
[0]Pluto:~ $ gvm -v 1.12.5
Runtime not found. Installing...
Downloaded   0.0% (    15173 / 127938445 bytes) ...
Downloaded  27.7% ( 35389440 / 127938445 bytes) ...
Downloaded  83.4% (106659840 / 127938445 bytes) ...
Downloaded 100.0% (127938445 / 127938445 bytes)
Unpacking /home/whearn/sdk/go1.12.5/go1.12.5.linux-amd64.tar.gz ...
Success. You may now run 'go1.12.5'
[0]Pluto:~ $ go version
go version go1.12.5 linux/amd64
[0]Pluto:~ $ gvm -v 1.12.6
[0]Pluto:~ $ go version
go version go1.12.6 linux/amd64
[0]Pluto:~ $