Set custom usage string showing the possibility to set jack client name (#2618)

diff --git a/jack_mixer.py b/jack_mixer.py
index b13eaa024ca1aba3fb618e1d670eb7622f594f64..b6d55e68a7a2d74c9b20eda6272543ffefd8b28e 100755 (executable)
--- a/jack_mixer.py
+++ b/jack_mixer.py
@@ -704,7 +704,7 @@ def main():
     else:
         lash_client = None
 
-    parser = OptionParser()
+    parser = OptionParser(usage='usage: %prog [options] [jack_client_name]')
     parser.add_option('-c', '--config', dest='config',
                       help='use a non default configuration file')
     # --no-lash here is not acted upon, it is specified for completeness when