1 files changed, 52 insertions, 0 deletions
diff --git a/nixpkgs/pkgs/development/interpreters/lua-5/hooks/setup-hook.sh b/nixpkgs/pkgs/development/interpreters/lua-5/hooks/setup-hook.sh
new file mode 100644
index 000000000000..7b2d2a4d83d8
--- /dev/null
+++ b/nixpkgs/pkgs/development/interpreters/lua-5/hooks/setup-hook.sh
@@ -0,0 +1,52 @@
+# set -e
+
+nix_print() {
+  if [ ${NIX_DEBUG:-0} -ge $1 ]; then
+    echo "$2"
+  fi
+}
+
+nix_debug() {
+  nix_print 3 "$1"
+}
+
+addToLuaSearchPathWithCustomDelimiter() {
+  local varName="$1"
+  local absPattern="$2"
+  # delete longest match starting from the lua placeholder '?'
+  local topDir="${absPattern%%\?*}"
+
+  # export only if the folder exists else LUA_PATH/LUA_CPATH grow too large
+  if [[ ! -d "$topDir" ]]; then return; fi
+
+  # 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 "${varName}=${!varName:+${!varName};}${absPattern}"
+}
+
+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
+}
+
+addEnvHooks "$hostOffset" addToLuaPath