uthng/golog

Simple logging library using golang log package.

golog

Simple logging library using golang log package. It uses io.Writer as output destination so it can log to stdout, stderr or into a file or multiple destinations at the same time using io.MultiWriter. Its is inspired of google/logger with some personal touches.

Documentation

See the Godoc

Usage

Set up a standard logger to stdout:

package main

import (
  "os"
  "github.com/uthng/common/golog"
)

function main() {
  golog.SetVerbosity(golog.DEBUG)

  golog.Debugln("This is debug log")
  golog.Infoln("This is info log")
  golog.Warnln("This is warn log")
  golog.Errorln("This is error log")
}

And when executed, the program will show the following output to the standard output:

DEBUG: 2018/11/12 02:08:57 log.go:161: This is debug log
INFO: 2018/11/12 02:08:57 log.go:161: This is info log
WARN: 2018/11/12 02:08:57 log.go:161: This is warn log
ERROR: 2018/11/12 02:08:57 log.go:161: This is error log

Set up multiple destinations

package main

import (
  "io"
  "os"
  "github.com/uthng/common/golog"
)

function main() {
  file, err := os.OpenFile("file.txt", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
  if err != nil {
	  os.Exit(-1)
  }

  multi := io.MultiWriter(file, os.Stdout)

  logger := golog.NewLogger()
  logger.SetVerbosity(golog.INFO)
  logger.SetOutput(multi)
  
  logger.Debugln("This is debug log")
  logger.Infoln("This is info log")
  logger.Warnln("This is warn log")
  logger.Errorln("This is error log")
}

When executed, the program will log to stdout and into file.txt the following output:

INFO: 2018/11/12 02:19:13 log.go:161: This is info log
WARN: 2018/11/12 02:19:13 log.go:161: This is warn log
ERROR: 2018/11/12 02:19:13 log.go:161: This is error log