1 files changed, 54 insertions, 0 deletions
diff --git a/pkgs/development/interpreters/lua-5/utils.sh b/pkgs/development/interpreters/lua-5/utils.sh
new file mode 100644
index 0000000000000..5491f8f7ad2d5
--- /dev/null
+++ b/pkgs/development/interpreters/lua-5/utils.sh
@@ -0,0 +1,54 @@
+#!/bin/sh
+nix_print() {
+  if [ ${NIX_DEBUG:-0} -ge $1 ]; then
+    echo "$2"
+  fi
+}
+
+nix_debug() {
+  nix_print 3 "$1"
+}
+
+addToLuaSearchPathWithCustomDelimiter() {
+  local varName="$1"
+  local absPattern="$2"
+
+  # export only if we haven't already got this dir in the search path
+  if [[ ${!varName-} == *"$absPattern"* ]]; then return; fi
+
+  # if the path variable has not yet been set, initialize it to ";;"
+  # this is a magic value that will be replaced by the default,
+  # allowing relative modules to be used even when there are system modules.
+  if [[ ! -v "${varName}" ]]; then export "${varName}=;;"; fi
+
+  # export only if the folder contains lua files
+  shopt -s globstar
+
+  local adjustedPattern="${absPattern/\?/\*\*\/\*}"
+  for _file in $adjustedPattern; do
+    export "${varName}=${!varName:+${!varName};}${absPattern}"
+    shopt -u globstar
+    return;
+  done
+  shopt -u globstar
+}
+
+addToLuaPath() {
+  local dir="$1"
+
+  if [[ ! -d "$dir" ]]; then
+    nix_debug "$dir not a directory abort"
+    return 0
+  fi
+  cd "$dir"
+  for pattern in @luapathsearchpaths@; do
+    addToLuaSearchPathWithCustomDelimiter LUA_PATH "$PWD/$pattern"
+  done
+
+  # LUA_CPATH
+  for pattern in @luacpathsearchpaths@; do
+    addToLuaSearchPathWithCustomDelimiter LUA_CPATH "$PWD/$pattern"
+  done
+  cd - >/dev/null
+}
+