Debugf log to level debug.

Errorf log to level error.

FatalfIf log to level error.

FatalIfError if err is not nil, then log to level fatal and call os.Exit.

Infof log to level info.

InitLog is an initialization for a logger level can be: debug info warn error.

InitLog2 specify advanced log config.

Warnf log to level warn.

WithLogger replaces default logger.

StdErr is the default configuration for log output.

StdOut configuration for log output.

Logger logger interface.