Extract rbenv-version-file{,-read,-write}

libexec/rbenv-version-origin

@@ -1,30 +1,8 @@
 #!/usr/bin/env bash
 set -e
 
-find_version_file() {
-  local root="$(pwd)"
-  while [ -n "$root" ]; do
-    if [ -e "${root}/.rbenv-version" ]; then
-      echo "${root}/.rbenv-version"
-      return 0
-    fi
-    root="${root%/*}"
-  done
-  return 1
-}
-
-DEFAULT_PATH="${HOME}/.rbenv/default"
-
-find_default_version_file() {
-  if [ -e "$DEFAULT_PATH" ]; then
-    echo "$DEFAULT_PATH"
-    return 0
-  fi
-  return 1
-}
-
-if [ -z "$RBENV_VERSION" ]; then
-  find_version_file || find_default_version_file || true
-else
+if [ -n "$RBENV_VERSION" ]; then
   echo "RBENV_VERSION environment variable"
+else
+  rbenv-version-file
 fi