About

A simple, high-performance, multi-threaded friendly golang logging library

This library provides convenient logging capabilities to stdout and logging to files.

It also provides simple and convenient custom extension capabilities.

Example

Print logs to standard output / console

package main

import (
	"github.com/liaoscdy/logger"
)

func main() {
	log := logger.NewDefaultLogger()
	log.SetCallDepth(2)
	log.SetLevel(logger.LevelDebug)
	log.Start()
	defer log.Close()

	// ------------------ print log msg
	log.Info("info Msg, value:%d", 1)
	log.Error("error Msg without any format value")
	log.Warn("warn Msg, Value1:%d, Value2:%s", 100, "stringByFmt")
}

Print logs to a file

package main

import (
	"github.com/liaoscdy/logger"
)

func main() {
	log := logger.NewLogger()
	// logging to file
	fileExecutor := logger.NewFileExecutor("/tmp/logger_test.log")
	fileExecutor.EnableFileRotate()
	fileExecutor.SetRotateMaxDays(7)
	log.AppendExecutor(fileExecutor)
	log.SetCallDepth(2)
	log.SetLevel(logger.LevelDebug)
	log.Start()
	defer log.Close()

	// ------------------ print log msg
	log.Info("info Msg, value:%d", 1)
	log.Error("error Msg without any format value")
	log.Warn("warn Msg, Value1:%d, Value2:%s", 100, "stringByFmt")
}

Print logs to files and standard output/console at the same time

package main

import (
	"github.com/liaoscdy/logger"
)

func main() {
	log := logger.NewLogger()
	log.AppendExecutor(logger.NewConsoleExecutor())
	log.AppendExecutor(logger.NewFileExecutor("/tmp/logger_test.log"))
	log.SetCallDepth(2)
	log.SetLevel(logger.LevelDebug)
	log.Start()
	defer log.Close()

	// ------------------ print log msg
	log.Info("info Msg, value:%d", 1)
	log.Error("error Msg without any format value")
	log.Warn("warn Msg, Value1:%d, Value2:%s", 100, "stringByFmt")
}

Customized

This log library supports custom log formatting and custom log output methods

Formatter

Implement Formatter to format the log into any format you want.

The definitions of the Formatter interface and LogMsg structure in this library are as follows:

type LogMsg struct {
    Level     LogLevel
    Timestamp time.Time
    Msg       string
    FileName  string
    FileLine  int
}

type Formatter interface {
    FormatMsg(msg *LogMsg) []byte
}

Here is a simple code example

import "github.com/liaoscdy/logger"

type CustomerFormatter struct{}

func (f *CustomerFormatter) FormatMsg(msg *logger.LogMsg) []byte {
	// example
	// ......
	return []byte(msg.Msg)
}

func main() {
	log := logger.NewLogger()
	log.SetLevel(logger.LevelInfo)
	log.SetCallDepth(2)
	log.AppendExecutor(logger.NewConsoleExecutor())
	log.SetFormatter(&CustomerFormatter{})
	log.Start()
	defer log.Close()

	log.Info("use the customer formatter")
}

Executor

Executor is responsible for outputting the formatted log information to where you want it.

Implement the Executor interface to customize your output method.

type Executor interface {
	WriteMsg(msg []byte) error
	Flush()
	Close()
}

Here is a simple code example

import (
	"github.com/liaoscdy/logger"
)

type CustomerExecutor struct{}

func (f *CustomerExecutor) WriteMsg(msg []byte) error {
	// ... your code here
	return nil
}

func (f *CustomerExecutor) Flush() {
	// ... your code here
	// ... responsible for persisting cached data
}

func (f *CustomerExecutor) Close() {
	// ... your code here
	// It is about to end and resources should be cleaned up
}

func main() {
	log := logger.NewLogger()
	log.SetLevel(logger.LevelInfo)
	log.SetCallDepth(2)
	log.AppendExecutor(&CustomerExecutor{})
	log.Start()
	defer log.Close()

	log.Info("use the customer formatter")
}