Update makefile

Author: 2-towns

Makefile

@@ -1,8 +1,8 @@
 # Destination folder for the downloaded libraries
 LIBS_DIR := $(abspath ./libs)
 
-UNAME_S := $(shell uname -s)
 # Flags for CGO to find the headers and the shared library
+UNAME_S := $(shell uname -s)
 ifeq ($(UNAME_S),Darwin)
 	CGO_CFLAGS  := -I$(LIBS_DIR)
 	CGO_LDFLAGS := -L$(LIBS_DIR) -lcodex -Wl,-rpath,@executable_path/libs
@@ -21,14 +21,17 @@ endif
 OS ?= "linux"
 ARCH ?= "amd64"
 VERSION ?= "v0.0.17"
-LATEST_URL := "https://github.com/codex-storage/codex-go-bindings/releases/latest/download/codex-${OS}-${ARCH}.zip"
-VERSIONED_URL := "https://github.com/codex-storage/codex-go-bindings/releases/download/$(VERSION)/codex-${OS}-${ARCH}.zip"
+DOWNLOAD_URL ?= "https://github.com/codex-storage/codex-go-bindings/releases/latest/download/codex-${OS}-${ARCH}.zip"
+
+ifneq ($(VERSION),)
+	DOWNLOAD_URL := "https://github.com/codex-storage/codex-go-bindings/releases/download/$(VERSION)/codex-${OS}-${ARCH}.zip"		
+endif
 
 all: run
 
 fetch: 
-	@echo "Fetching libcodex from GitHub Actions: ${LATEST_URL}"
-	curl -fSL --create-dirs -o $(LIBS_DIR)/codex-${OS}-${ARCH}.zip ${LATEST_URL}
+	@echo "Fetching libcodex from GitHub Actions from: ${DOWNLOAD_URL}"
+	curl -fSL --create-dirs -o $(LIBS_DIR)/codex-${OS}-${ARCH}.zip ${DOWNLOAD_URL}
 	unzip -o -qq $(LIBS_DIR)/codex-${OS}-${ARCH}.zip -d $(LIBS_DIR)
 	rm -f $(LIBS_DIR)/*.zip
 # Update the path to the shared library on macOS