Merge pull request #22 from nodenv/script-dir-symlinks

Resolves symlinks to get script dir

bin/nodenv-package-json-engine

@@ -6,12 +6,31 @@
 # test the installed versions against that range and print the
 # greatest matching version.
 
-# Setup for relative includes
+
+# Setup for relative includes. Adapted from:
+# http://www.ostricher.com/2014/10/the-right-way-to-get-the-directory-of-a-bash-script/
 # http://stackoverflow.com/a/12694189/407845
-DIR="${BASH_SOURCE%/*}"
-if [[ ! -d "$DIR" ]]; then DIR="$PWD"; fi
+get_script_dir() {
+  local dir
+  local src="${BASH_SOURCE[0]}"
 
-SEMVER="$DIR/../node_modules/sh-semver/semver.sh"
+  # while $src is a symlink, resolve it
+  while [ -h "$src" ]; do
+    dir="${src%/*}"
+    src="$( readlink "$src" )"
+
+    # If $src was a relative symlink (so no "/" as prefix),
+    # need to resolve it relative to the symlink base directory
+    [[ $src != /* ]] && src="$dir/$src"
+  done
+  dir="${src%/*}"
+
+  if [ -d "$dir" ]; then
+    echo "$dir"
+  else
+    echo "$PWD"
+  fi
+}
 
 find_package_json_path() {
   local root="$1"
@@ -50,6 +69,9 @@ version_from_package_json() {
   fi
 }
 
+DIR="$(get_script_dir)"
+SEMVER="$DIR/../node_modules/sh-semver/semver.sh"
+
 if should_find_in_package_json; then
   PACKAGE_JSON_PATH=$(find_package_json_path "$PWD")