gol

A small wrapper for standard log package in Go with enhanced prefixes.

Install

go get github.com/mitinarseny/gol

Documentation

See documentation for this package on GoDoc.

Usage

Create gol.Logger from log.Logger:

l := gol.New(log.New(os.Stdout, "", 0))

Type gol.Logger has *log.Logger embedded in it, so you can use all functions from log package.

You can use following functions to change prefix of logger:

l.SetPersistentPrefix("prefix")
l.SetPersistentPrefixf("%s pattern")
l.SetPrefix("prefix")
l.SetPrefixf("%s pattern")

All these functions return RestoreFunc which can be used to restore previous prefix. It is recommended to use it with defer keyword:

func someFunc() {
	defer l.SetPrefixf("  %s")()
	...
}

Example

Consider an example below:

// main.go
import (
	"os"
	"log"
	"github.com/mitinarseny/gol"
)

func main() {
	l := gol.New(log.New(os.Stdout, "", 0))
	
	r1 := l.SetPersistentPrefix("gol ")
	l.Println("is logger for Go with enhanced prefixes")
	
	r2 := l.SetPrefix("is cool because ")
	l.Println("you can grow prefixes easily")
	
	r3 := l.SetPrefixf("%syou ")
	l.Println("do not have to repeat yourself")
	
	r3()
	l.Println("it is easy to restore previous prefixes")
	
	r2()
	l.Println("is very cool")
	
	r1()
	l.Println("that's it :)")
}

This code will produce following output:

gol is logger for Go with enhanced prefixes
gol is cool because you can grow prefixes easily
gol is cool because you do not have to repeat yourself
gol is cool because a lot of reasnons
gol is very cool
that's it :)