Correctly display the size of the argument buffer we really allocated.

xargs/xargs.c

@@ -664,7 +664,18 @@ main (int argc, char **argv)
 	      (posix_arg_size_max - size_of_environment));
       fprintf(stderr,
 	      _("Size of command buffer we are actually using: %ld\n"),
-	      arg_size);
+	      bc_ctl.arg_max);
+      
+      if (isatty(STDIN_FILENO))
+	{
+	  fprintf(stderr,
+		  "\n"
+		  "Execution of xargs will continue now, and it will "
+		  "try to read its input and run commands; if this is "
+		  "not what you wanted to happen, please type the "
+		  "end-of-file keystroke.\n");
+	}
+      
     }
   
   linebuf = (char *) xmalloc (bc_ctl.arg_max + 1);