Changed command line and comment handling for script generator

* Changed to use argparse library for command line handling
* Added option to set search path for standard configuration (--path)
* Added use of config file comments in namelist files

getexp

@@ -5,6 +5,7 @@
 # $Id$
 #
 
+import argparse
 import os
 import sys
 
@@ -13,29 +14,42 @@ from feedback import die
 
 # Basic settings
 
-config_roots = os.environ.get('MKEXP_PATH', '').split(':')
 
 #
 # Main routine
 #
 
+# Check environment
+
+config_roots = os.environ.get('MKEXP_PATH', '').split(':')
+
 # Check command line
 
-program = sys.argv.pop(0)
-usage = 'Usage: ' + program + ' experiment_config_name [key=value...]'
+command_line = argparse.ArgumentParser(description=
+    'Generate an experiment from templates and the given configuration file.')
+command_line.add_argument('config', help='experiment configuration file name')
+command_line.add_argument('assigns', metavar='key=value', nargs='*',
+                           help='override configuration file settings')
+command_line.add_argument('--path', '-p', 
+                          help='search path for default config and templates')
+
+args = command_line.parse_args()
 
-if len(sys.argv) < 1:
-    die('invalid number of parameters\n' + usage)
+# Experiment configuration
+if args.path:
+    config_roots = args.path.split(':')
 
-experiment_config_name = sys.argv.pop(0)
+experiment_config_name = args.config
 
 if not os.path.exists(experiment_config_name):
     die("config file '{0}' does not exist".format(experiment_config_name))
 
-invalid_args = filter(lambda x: not x.find('=')+1, sys.argv)
+# Overrides
+invalid_args = filter(lambda x: not x.find('=')+1, args.assigns)
 
 if invalid_args:
-    die("invalid parameters ('"+"', '".join(invalid_args)+"')\n" + usage)
+    die("invalid parameters ('"+"', '".join(invalid_args)+"')\n" +
+        command_line.format_usage())
 
 # Read and store configuration info from input and experiments' library
 # Store environment as default for control settings, then add config from files
@@ -46,7 +60,7 @@ if os.environ.has_key('DIFF'):
 
 try:
     config = ExpConfig(experiment_config_name,
-                       dict(map(lambda x: x.split('=', 1), sys.argv)),
+                       dict(map(lambda x: x.split('=', 1), args.assigns)),
                        config_roots)
 except ExpConfigError as error:
     die(error.message, 2)