script to update terraform binary to (latest) version

terraform_update.sh

#!/usr/bin/env bash

set -ueo pipefail

function cleanup {
    rm -rf "$TMP"
}
TMP=$(mktemp -d)
trap cleanup EXIT
cd "$TMP"

VERSIONS=($(curl -fsSL https://releases.hashicorp.com/terraform/ | sed -n 's|\s*<a href="/terraform/\(.*\)/">.*|\1|p' | sort --version-sort --reverse))
if [ $# -gt 0 ]; then
    VER=$1
    if ! [[ " ${VERSIONS[@]} " =~ " ${VER} " ]]; then
        echo "Selected version '$VER' not found in available versions ${VERSIONS[@]}" >&2
        exit 1
    fi
else
    VER=${VERSIONS[0]}
    echo "Installing latest version $VER"
fi

mkdir -m=0700 gpg
gpg --quiet --homedir gpg --recv-key 'C874 011F 0AB4 0511 0D02 1055 3436 5D94 72D7 468F'
wget --quiet https://releases.hashicorp.com/terraform/$VER/terraform_${VER}_SHA256SUMS
wget --quiet https://releases.hashicorp.com/terraform/$VER/terraform_${VER}_SHA256SUMS.sig
if ! out=$(gpg --quiet --homedir gpg --verify terraform_${VER}_SHA256SUMS.sig 2>&1); then
    echo "$out" >&2
    exit 1
fi
wget --quiet https://releases.hashicorp.com/terraform/$VER/terraform_${VER}_linux_amd64.zip
sha256sum --quiet -c <(grep -F linux_amd64.zip terraform_${VER}_SHA256SUMS)
unzip -q terraform_${VER}_linux_amd64.zip terraform
if ! which terraform 2>/dev/null; then
    mkdir -p $HOME/.local/bin/
    mv terraform $HOME/.local/bin/
elif [[ "$(which terraform)" = /usr/* ]]; then
    sudo mv terraform $(which terraform)
else
    mv terraform $(which terraform)
fi
terraform --version