script to update go to new version on linux ubuntun

update_go.sh

#!/usr/bin/env bash
# Original author: Ravi Teja Pothana (@RaviTezu)
# Hugo: removed stuff I didn't need on Linux
set -e

GO_VERSION="invalid"
GO_ROOT=/usr/local/go

function usage {
    printf "./update_go.sh <version> \n"
    printf "Example: ./update_go.sh 1.12.1 \n"
    exit 1
}

if [ -z "$1" ]; then
    usage
else
    GO_VERSION=$1
fi

# Function to install golang and setup the env.
function install {
    echo

    PACKAGE=go$GO_VERSION.linux-amd64.tar.gz
    pushd /tmp > /dev/null
        echo
        if [ ! -f $PACKAGE ]; then
            echo "...... [ Downloading ]"
            wget https://dl.google.com/go/$PACKAGE
            if [ $? -ne 0 ]; then 
                echo "Failed to Download the package! Exiting."
                exit 1
            fi
        else
            echo "...... [ Package already downloaded, using it ]"
        fi

        # Check if there's any older version of GO installed on the machine. 
        if [ -d $GO_ROOT ]; then 
            echo "...... [ Removing an older version of GO ]"
            sudo rm -rf /usr/local/go
        fi

        echo "...... [ Installing ]"
        sudo tar -C /usr/local -xzf $PACKAGE
        rm -rf $PACKAGE
    popd > /dev/null
    echo "...... [ Installed ]"
    exit 0
}

echo "...... [ Welcome ]"
install