Automatically show help for a command when it fails with a syntax error

git-svn-id: https://urjtag.svn.sourceforge.net/svnroot/urjtag/trunk@1703 b68d4a1b-bc3d-0410-92ed-d4ac073336b7

urjtag/ChangeLog

@@ -3,6 +3,9 @@
   * src/cmd/cmd.h, src/cmd/cmd_list.h, src/cmd/cmd_cmd.c: Unify the list of
     commands in one place.
 
+  * src/cmd/cmd_cmd.c (urj_cmd_run): Automatically show help for a command
+    when it fails with a syntax error.
+
 2010-01-22  Mike Frysinger  <vapier@gentoo.org>
 
   * src/cmd/cmd_bit.c (cmd_bit_print_params): Fix strncat length handling.

urjtag/src/cmd/cmd_cmd.c

@@ -105,7 +105,13 @@ urj_cmd_run (urj_chain_t *chain, char *params[])
         if (strcasecmp (urj_cmds[i]->name, params[0]) == 0)
         {
           run_cmd:
-            return urj_cmds[i]->run (chain, params);
+            i = urj_cmds[i]->run (chain, params);
+            if (i != URJ_STATUS_OK && urj_error_get () == URJ_ERROR_SYNTAX)
+            {
+                char *help_params[3] = { "help", params[0], NULL };
+                urj_cmd_run( chain, help_params );
+            }
+            return i;
         }
         else if (strncasecmp (urj_cmds[i]->name, params[0], len) == 0)
         {