picolo

picolo

Minimalistic logging library.

Levels

LevelDebug
LevelInfo
LevelWarning
LevelError

Options

The constructor accepts several options:

WithLevel(level Level)                     // Set level
WithOutput(output io.Writer)               // Set output
WithPrefix(prefix string)                  // Set prefix
WithTimeFormat(format string, utc bool)    // Set time format and UTC flag

Defaults

If no options are given, the following are assumed.

WithLevel(LevelInfo)
WithOutput(os.Stdout)
WithTimeFormat(DefaultTimeFormat, true)

The default time format is 2006-01-02 15:04:05.000.

Usage

l := picolo.New() // Use defaults
l.Infof("Info message")
// 2017-12-21 22:23:24.256 INFO Info message

l = picolo.New(picolo.WithPrefix("[some-prefix]")) // constructor with optional prefix
l.Infof("Info message")
// 2017-12-21 22:23:24.256 INFO [some-prefix] Info message

// Create sub-logger, appending prefix
k := picolo.NewFrom(l, "[more-prefix]")
k.Errorf("Error message: %v", err)
//  2017-12-21 23:24:25.267 ERROR [some-prefix] [more-prefix] Error message: No such file or directory

Helpers

Use picolo.LevelFromString to parse a string into a log level. This can be used like:

// ...
l := flag.String("logLevel", "debug", "Log level")
flag.Parse()

lvl, err := picolo.LevelFromString(*l)
if err != nil {
	// Unknown log level
}

logger := picolo.New(picolo.WithLevel(lvl))
logger.Infof("One two three")
// ...