go get github.com/chzyer/logex

import "github.com/chzyer/logex" // package name is logex
func main() {
  logex.Info("Hello!")
}

import "github.com/chzyer/logex"
func main() {
  logex.Println("")
  logex.Debug("debug staff.") // Only show if has an "DEBUG" named env variable(whatever value).
  logex.Info("info")
  logex.Warn("")
  logex.Fatal("") // also trigger exec "os.Exit(1)"
  logex.Error(err) // print error
  logex.Struct(obj) // print objs follow such layout "%T(%+v)"
  logex.Pretty(obj) // print objs as JSON-style, more readable and hide non-publish properties, just JSON
}

type MyStruct struct {
  BiteMe bool
}

type MyStruct struct {
  BiteMe bool
  logex.Logger // just this
}
func main() {
  ms := new(MyStruct)
  ms.Info("woo!")
}

package main
import "github.com/chzyer/logex"
func test() {
	logex.Pretty("hello")
}
func main() {
	test()
}

2014/10/10 15:17:14 [main.test:testlog.go:6][PRETTY] "hello"

package main
import (
	"github.com/chzyer/logex"
	"os"
)
func openfile() (*os.File, error) {
	f, err := os.Open("xxx")
	if err != nil {
		err = logex.Trace(err)
	}
	return f, err
}
func test() error {
	f, err := openfile()
	if err != nil {
		return logex.Trace(err)
	}
	f.Close()
	return nil
}
func main() {
	err := test()
	if err != nil {
		logex.Error(err)
		return
	}
	logex.Info("test success")
}

2014/10/10 15:22:29 [main.main:testlog.go:28][ERROR] [main.openfile:11;main.test:19] open xxx: no such file or directory