pyenv/libexec/rbenv-sh-shell

#!/bin/sh

if [ -z "$1" ]; then
  echo "Please specify one of the following Ruby versions to use:" >&2
  echo "" >&2
  echo "$(rbenv-versions)" >&2
  exit 1
fi

version=$1

if [ -d "$HOME/.rbenv/versions/$version" ]; then
  echo "export RBENV_VERSION=$version"
else
  case $version in
    default|reset)
      echo "unset RBENV_VERSION"
      ;;
    *)
      echo "rbenv: version \`$version' is not installed" >&2
      exit 1
  esac
fi