From d27767d78215254406fe06bac825a49a2c1a5a77 Mon Sep 17 00:00:00 2001
From: Dan Howe <d.howe@wrl.unsw.edu.au>
Date: Thu, 19 Apr 2018 07:58:53 +1000
Subject: [PATCH] Print usage if no arguments are provided

---
 dxf_to_csv/dxf_to_csv.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/dxf_to_csv/dxf_to_csv.py b/dxf_to_csv/dxf_to_csv.py
index f1e4bf2..48f31f1 100644
--- a/dxf_to_csv/dxf_to_csv.py
+++ b/dxf_to_csv/dxf_to_csv.py
@@ -122,9 +122,14 @@ def main():
         '-n', metavar='LAYER_NAME', help='name of layer', default=None)
     parser.add_argument(
         '-l', action='store_true', help='show list of layers', default=False)
-    args = parser.parse_args()
+
+    # List usage if no arguments are provided
+    if len(sys.argv) == 1:
+        parser.print_help(sys.stderr)
+        sys.exit(1)
 
     # Parse arguments
+    args = parser.parse_args()
     dxf_name = args.dxf_name
     layer_name = args.n
     show_layers_only = args.l