New file. Sieve-specific command line handling.

+/* GNU mailutils - a suite of utilities for electronic mail
+   Copyright (C) 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif  
+#include <sieve.h>
+#include <mailutils/argp.h>
+#include <string.h>
+
+list_t sieve_include_path = NULL;
+list_t sieve_library_path = NULL;
+
+static error_t sieve_argp_parser __P((int key, char *arg,
+					struct argp_state *state));
+
+/* Options used by programs that use extended authentication mechanisms. */
+static struct argp_option sieve_argp_option[] = {
+  { "includedir", 'I', "DIR", 0,
+    "Append directory DIR to the list of directories searched for include files", 0 },
+  { "libdir", 'L', "DIR", 0,
+    "Append directory DIR to the list of directories searched for library files", 0 },
+  { NULL,      0, NULL, 0, NULL, 0 }
+};
+
+static struct argp sieve_argp = {
+  sieve_argp_option,
+  sieve_argp_parser,
+};
+
+static struct argp_child sieve_argp_child = {
+  &sieve_argp,
+  0,
+  "Sieve options",
+  0
+};
+
+static error_t
+sieve_argp_parser (int key, char *arg, struct argp_state *state)
+{
+  list_t *plist = NULL;
+  
+  switch (key)
+    {
+    case 'I':
+      plist = &sieve_include_path;
+      break;
+
+    case 'L':
+      plist = &sieve_library_path;
+      break;
+
+    case ARGP_KEY_FINI:
+      sieve_load_add_path (sieve_library_path);
+      break;
+			   
+    default:
+      return ARGP_ERR_UNKNOWN;
+    }
+
+  if (plist)
+    {
+      if (!*plist)
+	{
+	  int rc = list_create (plist);
+	  if (rc)
+	    {
+	      argp_error (state, "can't create list: %s",
+			mu_errstring (rc));
+	      exit (1);
+	    }
+	}
+      list_append (*plist, strdup (arg));
+    }
+	  
+  return 0;
+}
+
+void
+sieve_argp_init ()
+{
+  if (mu_register_capa ("sieve", &sieve_argp_child))
+    {
+      mu_error ("INTERNAL ERROR: cannot register argp capability sieve");
+      abort ();
+    }
+}