diff options
-rw-r--r-- | pkg/log/log.go | 139 | ||||
-rw-r--r-- | pkg/log/log_test.go | 21 |
2 files changed, 160 insertions, 0 deletions
diff --git a/pkg/log/log.go b/pkg/log/log.go new file mode 100644 index 0000000..ad4a692 --- /dev/null +++ b/pkg/log/log.go @@ -0,0 +1,139 @@ +// package log provides a simple logger with leveled log messages. +// +// - DebugLevel (highest verbosity) +// - InfoLevel +// - WarningLevel +// - ErrorLevel +// - FatalLevel (lowest verbosity) +// +// Output is by default written to STDERR. +// A different output can be specified. +// Dates and terminal colors can be turned on. +package log + +import ( + "io" + "log" + "os" + "time" +) + +type level int + +const ( + DebugLevel level = iota // DebugLevel logs all messages + InfoLevel // InfoLevel logs info messages and and above + WarningLevel // WarningLevel logs warning messages and above + ErrorLevel // ErrorLevel logs error messages and above + FatalLevel // FatalLevel only logs fatal messages +) + +const ( + colorDate = "\033[37m" + colorDebug = "\033[95m" + colorInfo = "\033[94m" + colorWarning = "\033[93m" + colorError = "\033[91m" + colorFatal = "\033[31m" + colorReset = "\033[0m" + + tagDebug = "DEBU" + tagInfo = "INFO" + tagWarning = "WARN" + tagError = "ERRO" + tagFatal = "FATA" +) + +type logger struct { + log.Logger + + lv level + date bool + color bool +} + +var l logger + +func init() { + l = newLogger(InfoLevel, os.Stderr, false, false) +} + +// SetLevel sets the logging level. Available options: DebugLevel, InfoLevel, +// WarningLevel, ErrorLevel, FatalLevel. Default: InfoLevel. +func SetLevel(lv level) { + l.lv = lv +} + +// SetOutput sets the logging output to a particular writer. Default: os.Stderr. +func SetOutput(writer io.Writer) { + l = newLogger(l.lv, writer, l.date, l.color) +} + +// SetDate (un)sets date output. Default: off. +func SetDate(ok bool) { + l.date = ok +} + +// SetColor (un)sets terminal colors. Default: off. +func SetColor(ok bool) { + l.color = ok +} + +func Debug(format string, v ...interface{}) { + if l.lv > DebugLevel { + return + } + + l.Printf(l.fmt(tagDebug, colorDebug)+format, v...) +} + +func Info(format string, v ...interface{}) { + if l.lv > InfoLevel { + return + } + + l.Printf(l.fmt(tagInfo, colorInfo)+format, v...) +} + +func Warning(format string, v ...interface{}) { + if l.lv > WarningLevel { + return + } + + l.Printf(l.fmt(tagWarning, colorWarning)+format, v...) +} + +func Error(format string, v ...interface{}) { + if l.lv > ErrorLevel { + return + } + + l.Printf(l.fmt(tagError, colorError)+format, v...) +} + +func Fatal(format string, v ...interface{}) { + l.Printf(l.fmt(tagFatal, colorFatal)+format, v...) + os.Exit(1) +} + +func newLogger(lv level, writer io.Writer, date, color bool) logger { + return logger{ + Logger: *log.New(writer, "", 0), + lv: lv, + date: date, + color: color, + } +} + +func (l *logger) fmt(tag, colorTag string) string { + date := "" + if l.date { + date = time.Now().Format(time.RFC1123) + " " + } + if l.color { + date = colorDate + date + colorReset + tag = colorTag + tag + colorReset + } + tag = "[" + tag + "] " + return date + tag +} diff --git a/pkg/log/log_test.go b/pkg/log/log_test.go new file mode 100644 index 0000000..9f4076d --- /dev/null +++ b/pkg/log/log_test.go @@ -0,0 +1,21 @@ +package log + +import ( + "os" +) + +func Example() { + SetOutput(os.Stdout) + SetLevel(WarningLevel) + SetDate(false) + SetColor(false) + + Debug("some debug number: %d\n", 10) + Info("some info number: %d\n", 20) + Warning("some warning number: %d\n", 30) + Error("some error number: %d\n", 40) + + // Output: + // [WARN] some warning number: 30 + // [ERRO] some error number: 40 +} |