diff --git a/Makefile b/Makefile
index 71ecb485ad059da37b4e4c5730e5e7cc58f78d8d..f396ec00ad9ff6563f892876a5222888e8d86b19 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@ publish: build
 
 .PHONY: build
 build: mathjax
-	cd fgs && python3 __main__.py
+	cd fgs && python3 __main__.py "../content" "../output" "../theme" "../config.json" "../lang.json"
 
 .PHONY: mathjax
 mathjax:
diff --git a/fgs/__main__.py b/fgs/__main__.py
index fc870f06befb882029455ab2e311256ba7e4934b..0a14ceb46c8cff2e90d464b8abc52da170fb8cba 100644
--- a/fgs/__main__.py
+++ b/fgs/__main__.py
@@ -12,21 +12,23 @@ import reader
 import generator
 import writer
 
-CONTENT_DIR = '../content'
-OUTPUT_DIR = '../output'
-THEME_DIR = '../theme'
+#content_dir = '../content'
+#output_dir = '../output'
+#theme_dir = '../theme'
+#config_file = '../config.json'
+#lang_file = '../lang.json'
 
 
-def main():
+def main(content_dir, output_dir, theme_dir, config_file, lang_file):
     print("Hello World")
     config = {}
-    with open('../config.json') as f:
+    with open(config_file) as f:
         config = common.combine(config, json.loads(f.read()))
-    with open('../lang.json') as f:
+    with open(lang_file) as f:
         if 'lang' not in config:
             config['lang'] = {}
         config['lang'] = common.combine(config['lang'], json.loads(f.read()))
-    with open(CONTENT_DIR + '/config.json') as f:
+    with open(content_dir + '/config.json') as f:
         config = common.combine(config, json.loads(f.read()))
     print(config)
 
@@ -49,15 +51,15 @@ def main():
             extensions = mimeconfig['extensions']
         readers.append(reader.PandocReader(config, factories, mimetype, None, base=mimeconfig['base'], extensions=extensions))
 
-    read_dir(os.path.join(CONTENT_DIR, "."), readers)
-    read_dir(THEME_DIR + '/static', readers, [config['theme']['static_dir']])
+    read_dir(os.path.join(content_dir, "."), readers)
+    read_dir(theme_dir + '/static', readers, [config['theme']['static_dir']])
 
 
     context = {}
     gen = generator.Generator(config, context, factories)
     gen.generate_context()
 
-    wrt = writer.Writer(config, context, OUTPUT_DIR, THEME_DIR)
+    wrt = writer.Writer(config, context, output_dir, theme_dir)
 
     gen.generate_output(wrt)
 
@@ -91,5 +93,9 @@ def read_dir(directory, readers, subpath = []):
 
 
 if __name__ == '__main__':
-    main()
+    argv = sys.argv
+    if len(argv) != 6:
+        print("Usage:",argv[0],"<content_dir> <output_dir> <theme_dir> <config_file> <lang_file>")
+        os._exit(1)
+    main(argv[1], argv[2], argv[3], argv[4], argv[5])