ruby-build-update

#!/bin/sh
set -euf
out () { printf %s\\n "$*" ; }

##
# Use the `ruby-build` program to install Ruby in our preferred locations.
#
# We put the `ruby-build` git repo here:
#
#     /opt/ruby-build
#
# We install Ruby MRI here:
#
#    /opt/ruby/<version>
#
# Example installation directory:
#
#    /opt/ruby/3.0.2
#
# Syntax:
#
#    ruby-build-update [version [-c]]
#
# Contact: Joel Parker Henderson (joel@joelparkerhenderson.com)
# License: GPL
# Updated: 2021-07-17T19:15:44Z
##

# Get the official Ruby interpreter current version.
#
# Example: "3.0.2"
#
ruby_build_definition_of_yarv_current() {
  ruby-build --definitions | grep "^[0-9]\+\.[0-9]\+\.[0-9]\+$" | tail -1
}

## Input

if [ "$#" -eq 0 ]; then
  RUBY_VERSION=$(ruby_build_definition_of_yarv_current)
  CREATE_CURRENT_SYMLINK=1 #true
else
  RUBY_VERSION=$1
  RUBY_VERSION_SANS_SUFFIX=${RUBY_VERSION%%-p*}  # e.g. "3.0.2" but not "3.0.2-dev"
  CREATE_CURRENT_SYMLINK=$2
fi

## Config

RUBY_BUILD_DIR=/opt/ruby-build
RUBY_DIR=/opt/ruby

## Install

# Install ruby-build as needed
test -d "$RUBY_BUILD_DIR" || sudo git clone https://github.com/sstephenson/ruby-build "$RUBY_BUILD_DIR"

# Update ruby-build
cd "$RUBY_BUILD_DIR" && git pull && ./install.sh

# Create ruby directory as needed
test -d " $RUBY_DIR" || mkdir -p "$RUBY_DIR"

# Install Ruby as needed
test -d "$RUBY_DIR/$RUBY_VERSION" || ruby-build "$RUBY_VERSION" "$RUBY_DIR/$RUBY_VERSION"

# Create `current` symlink

if [ "$CREATE_CURRENT_SYMLINK" -eq 1 ]; then
  cd "$RUBY_DIR"
  ln -nsf "$RUBY_VERSION" current
  source /etc/environment
  ruby -v
fi