Re: [Discuss-gnuradio] Suppressing UHD prints

From 222df48d16d03447ef7e6452c046e349cbc0936c Mon Sep 17 00:00:00 2001
From: Sebastian Koslowski <koslowski@kit.edu>
Date: Thu, 2 Jul 2015 16:42:35 +0200
Subject: [PATCH] uhd: add null msg handler and expose to python

---
gr-uhd/swig/uhd_swig.i | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/gr-uhd/swig/uhd_swig.i b/gr-uhd/swig/uhd_swig.i
index 108f544..6c73ba3 100644
--- a/gr-uhd/swig/uhd_swig.i
+++ b/gr-uhd/swig/uhd_swig.i
@@ -68,6 +68,14 @@

%include <uhd/utils/pimpl.hpp>

+%{
+#include <uhd/utils/msg.hpp>
+static void null_msg_handler(uhd::msg::type_t type, const std::string &msg){}
+%}
+%constant void null_msg_handler(uhd::msg::type_t type, const std::string &msg);
+%rename(register_msg_handler) register_handler(const handler_t &handler);
+%include <uhd/utils/msg.hpp>
+
%ignore uhd::dict::operator[]; //ignore warnings about %extend
%include <uhd/types/dict.hpp>
%template(string_string_dict_t) uhd::dict<std::string, std::string>; //define after dict
--
1.9.3

On 07/01/2015 10:19 AM, Piotr Krysik wrote:

Hi all,    UHD host library generates prints on the stdout. For example on each  retune I get something like:    -- Tune Request: 959.000000 MHz  --   The RF LO does not support the requested frequency:  --     Requested LO Frequency: 959.000000 MHz  --     RF LO Result: 958.998779 MHz  --   Attempted to use the DSP to reach the requested frequency:  --     Desired DSP Frequency: -0.001221 MHz  --     DSP Result: -0.001221 MHz  --   Successfully tuned to 959.000000 MHz  

These prints are sometimes cluttering the console - especially when  someone wants to use console to print other useful information.    There is possibility to disable them in UHD from the level of C++:  http://files.ettus.com/manual/page_general.html  ("Disabling or redirecting prints to stdout")    Is it possible to disable the prints from GNU Radio?

I had looked into that some time ago. In the current form it is not possible.

Even if ' uhd::msg::register_handler' would be exposed to python, you still can't drop-in your own null-handler. Swig doesn't support callbacks in the target language (python). However, you can add custom handlers like a null_handler in C++ and then use that. Try the attached patch. Works for me.  Only output left is that standard version_string.

Sebastian