tint: π slog.Handler that writes tinted logs
Package tint provides a slog.Handler that writes tinted (colorized) logs. The output format is inspired by the zerolog.ConsoleWriter.
The output format can be customized using Options which is a drop-in replacement for slog.HandlerOptions.
go get github.com/lmittmann/tint
Note
slog is an experimental structured logging package, that will be added to the standard library in Go 1.21. See #56345 for tracking the progress.
Usage
// create a new logger
logger := slog.New(tint.NewHandler(os.Stderr, nil))
// set global logger with custom options
slog.SetDefault(slog.New(
tint.NewHandler(os.Stderr, &tint.Options{
Level: slog.LevelDebug,
TimeFormat: time.Kitchen,
}),
))Customize
ReplaceAttr can be used to alter or drop attributes. If set, it is called on
each non-group attribute before it is logged. See slog.HandlerOptions
for details.
// create a new logger that doesn't write the time
logger := slog.New(tint.NewHandler(os.Stderr, &tint.Options{
ReplaceAttr: func(groups []string, a slog.Attr) slog.Attr {
if a.Key == slog.TimeKey && len(groups) == 0 {
return slog.Attr{}
}
return a
},
}))Automatically Enable/Disable Colors
Colors are enabled by default and can be disabled using the Options.NoColor
attribute. To automatically enable colors based on the terminal capabilities,
use e.g. the go-isatty package.
w := os.Stderr
logger := slog.New(
tint.NewHandler(w, &tint.Options{
NoColor: !isatty.IsTerminal(w.Fd()),
}),
)Windows Support
Color support on Windows can be added by using e.g. the
go-colorable package.
w := os.Stderr
logger := slog.New(
tint.NewHandler(colorable.NewColorable(w), nil),
)