wlog

Simple log level based Go logger. Provides an io.Writer that filters log messages based on a log level prefix. Valid log levels are: DEBUG, INFO, WARN, ERROR, OFF. Log messages need to begin with a L! where L is one of D, I, W, or E.

Usage

Create a *log.Logger via wlog.New:

package main

import (
    "log"
    "os"

    "github.com/influxdata/wlog"
)

func main() {
    var logger *log.Logger
    logger = wlog.New(os.Stderr, "prefix", log.LstdFlags)
    logger.Println("I! initialized logger")
}

Create a *log.Logger explicitly using wlog.Writer:

package main

import (
    "log"
    "os"

    "github.com/influxdata/wlog"
)

func main() {
    var logger *log.Logger
    logger = log.New(wlog.NewWriter(os.Stderr), "prefix", log.LstdFlags)
    logger.Println("I! initialized logger")
}

Prefix log messages with a log level char and the ! delimiter.

logger.Println("D! this is a debug log")
logger.Println("I! this is an info log")
logger.Println("W! this is a warn log")
logger.Println("E! this is an error log")

The log level can be changed via the SetLevel or the SetLevelFromName functions.

package main

import (
    "log"
    "os"

    "github.com/influxdata/wlog"
)

func main() {
    var logger *log.Logger
    logger = wlog.New(os.Stderr, "prefix", log.LstdFlags)
    wlog.SetLevel(wlog.DEBUG)
    logger.Println("D! initialized logger")
    wlog.SetLevelFromName("INFO")
    logger.Println("D! this message will be dropped")
    logger.Println("I! this message will be printed")
}