picolo

picolo is a minimalistic logging library for go.

Usage

If no options are given, picolo assumes:

• log level is INFO
• output is os.Stdout
• time format is 2006-01-02 15:04:05.000
• prefix is empty string

l := picolo.New() // Use defaults
l.Infof("Info message")
// 2019-04-29 15:34:32.166 INFO Info message

prefix can be set with picolo.WithPrefix option.

l = picolo.New(picolo.WithPrefix("[some-prefix]")) // constructor with optional prefix
l.Infof("Info message")
// 2019-04-29 22:23:24.256 INFO [some-prefix] Info message

Sub loggers can be created from an existing logger with picolo.NewFrom constructor function.

// Create sub-logger, appending prefix
k := picolo.NewFrom(l, "[more-prefix]")
k.Errorf("Error message: %v", err)
//  2019-04-29 23:24:25.267 ERROR [some-prefix] [more-prefix] Error message: No such file or directory

Log Levels

picolo supports 4 types of log levels:

• DEBUG
• INFO
• WARNING
• ERROR

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

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("Logger is ready.")
// ...