add help text

sssg/cli.py

@@ -5,7 +5,10 @@ import sys
 import os
 
 def main(args=sys.argv):
-    command = args[1]
+    try:
+        command = args[1]
+    except IndexError:
+        command = "nonexistent"
 
     if command == "rebuild":
         cwd = os.getcwd()
@@ -15,3 +18,16 @@ def main(args=sys.argv):
         os.execv('/bin/sh', ['/bin/sh', '.deploy'])
     elif command == "update":
         sssg.liveupdate.liveupdate()
+    else:
+        help_text = """
+sssg - the stupid static site generator
+
+usage: sssg [verb]
+
+verb: one of
+    rebuild -- rebuilds the static site into output/
+    deploy -- executes the deploy script
+    update -- rebuild the static site upon any change
+"""
+
+        print(help_text)