#include <nng/nng.h>
typedef void (*nng_logger)(nng_log_level level, nng_log_facility facility,
const char *msgid, const char *msg);
void nng_null_logger(nng_log_level, nng_log_facility, const char *, const char *);
void nng_stderr_logger(nng_log_level, nng_log_facility, const char *, const char *);
void nng_system_logger(nng_log_level, nng_log_facility, const char *, const char *);
void nng_log_set_logger(nng_logger logger);nng_log_set_logger(3)
NAME
nng_log_set_logger - set logging handler
SYNOPSIS
DESCRIPTION
The nng_log_set_logger is used to set the base logging function to logger.
The logger may be a user defined function to process log messages.
Only a single logger may be registered at a time.
If needed, the logger should make copies of either msgid or msg, as those may not be valid once the logger function returns.
The nng_null_logger function is an implementation of nng_logger that simply discards the content.
This is the default logger, so logging is disabled by default.
The nng_stderr_logger function is an implementation that logs messages to the standard error stream.
It will attempt to colorize messages by the severity, if the standard error is a terminal device.
This can be supressed by setting either the NO_COLOR or NNG_LOG_NO_COLOR environment variables.
The nng_system_logger attempts to use an appropriate system facility to log messages.
For POSIX systems, this means using syslog to process the messages.
For other the nng_stderr_log may be used as a fallback.