Executive Summary

This support class bskLogger enables C++ bskLog() and ANSI-C _bskLog() method to be used to log various debug, information, warning and error messages. The verbosity, i.e. what level of messages are printed to the terminal, can be set from the Basilisk python script.

Verbosity Level Options




Can be used for debug information logging. Such bskLog statement should not be left in the final Basilisk code.


General information messages


Warnings about unexpected behavior, but not outright errors.


Erroneous behavior that needs to be fixed.


This level is used to silence all bskLog statements. This should never be used with the bskLog method within the C++ or C code.

Class Assumptions and Limitations

The bskLogger class is intended to be used primarily within the BSK modules. All the modules must have been initialized before the bskLog becomes effective. Thus, if bskLog is used during initialization to print a warning, this will not function as expected.

For utility libraries such as linearAlgebra.c/h etc., this logging capabilities is not applicable as these libraries don’t have access to the bskLogger instance. Rather, in such cases use the BSK_PRINT() macro instead.

Using bskLogger From Python

For an example of how to set the verbosity from Python, see scenarioBskLog. The default verbosity is set to the lowest level BSK_DEBUG such that any bskLog method print out the associated message string. If this is the desired behavior, then no further actions are required.

If the verbosity level is to be changed for a particular Basilisk script, then the following instructions explain how this can be done. At the top of the Basilisk python scrip be sure to include the bskLogging support package:

from Basilisk.simulation import bskLogging

Setting Verbosity Globally for all BSK Modules

The bskLog verbosity can be modified for all Basilisk modules by using:


The verbosity options are listed in the table above. Note that this command must be included at the very beginning of the Basilisk simulation script, certainly before the call for SimulationBaseClass.SimBaseClass().

Changing Verbosity for a Particular BSK Module

It is possible to override the global verbosity setting and specify a different verbosity for a particular module. Assume we want to have a unique verbosity level for the simpleNav module. This can be done through:

sNavObject = simple_nav.SimpleNav()
scSim.AddModelToTask(simTaskName, sNavObject)
logger = bskLogging.BSKLogger()
sNavObject.bskLogger = logger

Another option is to use the BSKLogger() constructor to provide the verbosity directly through:

sNavObject = simple_nav.SimpleNav()
sNavObject.bskLogger = bskLogging.BSKLogger(bskLogging.BSK_INFORMATION)

Unlike change the global verbosity level, the module specific verbosity can be changed later on in the Basilisk python script as the corresponding module is created and configured.

Using bskLog in C++ Basilisk Modules

The first step is to include the bskLogging support file with the module *.h file using:

#include "architecture/utilities/bskLogging.h"

Next, the module class must contain the following public variable:

BSKLogger bskLogger;

Within the *.cpp file, the bskLog() method can be called with:

bskLogger.bskLog(BSK_INFORMATION, "%d %d", arg1, arg2);

Using _bskLog in C Basilisk Modules

The first step is to include the bskLogging support file with the module *.h file using:

#include "architecture/utilities/bskLogging.h"

The C-module configuration structure must contain a pointer to the BSKLogger type using:

BSKLogger *bskLogger;

The _bskLog only accepts char*/string, so the formatting must be done before logging call. If it is a simple message without any variables being included, then you can use:

_bskLog(configData->bskLogger, BSK_INFORMATION, "Fixed String");

If you want to print variables to the logging string, this must be done before calling _bskLog, such as in this example:

sprintf(info, "Variable is too large (%d). Setting to max value.", variable);
_bskLog(configData->bskLogger, BSK_ERROR, info);




enum logLevel_t


enumerator BSK_DEBUG
enumerator BSK_WARNING
enumerator BSK_ERROR
enumerator BSK_SILENT


void printDefaultLogLevel()


logLevel_t LogLevel