Update R from last-success branch builds

update-R.sh

#!/bin/bash

set -e

arch=$(uname -m)
if [ -z "$1" ]; then
    echo ''
    echo " Usage: $0 <version>"
    echo ''
    echo " Will fetch R-<version>-branch-$arch.tar.xz so use something like"
    echo " $0 4.5"
    echo ""
    echo " Can also be 'devel' in which case it fetches R-devel"
    exit 1
fi
BV="$1"
if [ "$BV" = devel ]; then
    fn="R-devel"
else
    fn="R-$BV-branch"
fi
cd /Library/Frameworks/R.framework/Versions
echo "Fetching and unpacking ${fn}-${arch}.tar.xz ..."
curl -sS https://mac.r-project.org/big-sur/last-success/${fn}-${arch}.tar.xz | tar xj
ver=$(ls R.framework/Versions | grep ${arch})
echo " - yields $ver"
rm -rf ${ver}-old
if [ -e ${ver} ]; then
    echo " - remove ${ver}-old"
    mv ${ver} ${ver}-old
fi
echo " - move new into $ver"
mv R.framework/Versions/$ver . && rm -rf R.framework

R_HOME=/Library/Frameworks/R.framework/Versions/$ver/Resources /Library/Frameworks/R.framework/Versions/$ver/Resources/bin/exec/R --version | head -n4