1 files changed, 113 insertions, 0 deletions
diff --git a/tools/permutations.c b/tools/permutations.c
new file mode 100644
index 0000000000..a582101fdf
--- /dev/null
+++ b/tools/permutations.c
@@ -0,0 +1,113 @@
+/*
+ * Generates all possible matching inputs for a command string.
+ * --
+ * Copyright (C) 2016 Cumulus Networks, Inc.
+ *
+ * This file is part of GNU Zebra.
+ *
+ * GNU Zebra is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * GNU Zebra 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Zebra; see the file COPYING.  If not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#include "command.h"
+#include "graph.h"
+#include "command_parse.h"
+#include "vector.h"
+
+#define USAGE "usage: permutations <cmdstr>"
+
+void
+permute (struct graph_node *);
+void
+pretty_print_graph (struct graph_node *start, int level);
+
+int main (int argc, char *argv[])
+{
+  if (argc < 2)
+  {
+    fprintf(stdout, USAGE"\n");
+    exit(EXIT_SUCCESS);
+  }
+  struct cmd_element *cmd = calloc (1, sizeof (struct cmd_element));
+  cmd->string = strdup(argv[1]);
+
+  struct graph *graph = graph_new();
+  struct cmd_token *token = new_cmd_token (START_TKN, NULL, NULL);
+  graph_new_node (graph, token, NULL);
+  command_parse_format (graph, cmd);
+
+  permute (vector_slot (graph->nodes, 0));
+  pretty_print_graph (vector_slot (graph->nodes, 0), 0);
+}
+
+void
+permute (struct graph_node *start)
+{
+  static struct list *position = NULL;
+  if (!position) position = list_new ();
+
+  // recursive dfs
+  listnode_add (position, start);
+  for (unsigned int i = 0; i < vector_active (start->to); i++)
+  {
+    struct graph_node *gn = vector_slot (start->to, i);
+    struct cmd_token *tok = gn->data;
+    if (tok->type == END_TKN)
+    {
+      struct graph_node *gnn;
+      struct listnode *ln;
+      for (ALL_LIST_ELEMENTS_RO (position,ln,gnn))
+      {
+        struct cmd_token *tt = gnn->data;
+        if (tt->type < SELECTOR_TKN)
+          fprintf (stdout, "%s ", tt->text);
+      }
+      fprintf (stdout, "\n");
+    }
+    else
+      permute (gn);
+  }
+  list_delete_node (position, listtail(position));
+}
+
+void
+pretty_print_graph (struct graph_node *start, int level)
+{
+  // print this node
+  struct cmd_token *tok = start->data;
+  fprintf (stdout, "%s[%d] ", tok->text, tok->type);
+
+  int numto = vector_active (start->to);
+  if (numto)
+    {
+      if (numto > 1)
+        fprintf (stdout, "\n");
+      for (unsigned int i = 0; i < vector_active (start->to); i++)
+        {
+          struct graph_node *adj = vector_slot (start->to, i);
+          // if we're listing multiple children, indent!
+          if (numto > 1)
+            for (int j = 0; j < level+1; j++)
+              fprintf (stdout, "    ");
+          // if this node is a vararg, just print *
+          if (adj == start)
+            fprintf (stdout, "*");
+          else
+            pretty_print_graph (adj, numto > 1 ? level+1 : level);
+        }
+    }
+  else
+    fprintf(stdout, "\n");
+}