Logging

The load_env_log_level() (C++/Python) function loads the logging level from the environment variable HOLOSCAN_LOG_LEVEL (default: INFO).

            

            
#include <holoscan/holoscan.hpp>

int main() {
  holoscan::load_env_log_level();
  // ...
  return 0;
}
        

            

            
from holoscan.logger import load_env_log_level

def main():
    load_env_log_level()
    # ...

if __name__ == "__main__":
    main()
        

HOLOSCAN_LOG_LEVEL can be set to one of the following values:

• TRACE

• DEBUG

• INFO

• WARN

• ERROR

• CRITICAL

• OFF

            

            
export HOLOSCAN_LOG_LEVEL=TRACE
        

The C++ API uses the HOLOSCAN_LOG_XXX() macros to log messages in the application. These macros use the fmtlib format string syntax for their format strings.

Users of the Python API should use the built-in logging module to log messages. Users can control the logging of any underlying C++ Operators used via their Python bindings via the functions in the holoscan.logger module. Specifically, calling load_env_log_level() will load the logging level from the HOLOSCAN_LOG_LEVEL environment variable described above. This log level can also be changed at runtime via set_log_level() using the LogLevel() enum class (e.g. set_log_level(LogLevel.WARN)).