Marker is the easiest way to match and mark strings for colorful terminal outputs.
Marker is built for easily match and mark strings for colorful terminal outputs. You can match your strings with built-in matchers or easily implement a custom matcher for your usecase. Marker uses fatih/color for colorizing terminal output.
go get github.com/cyucelen/marker
Marker has very simple and extensible way to get your strings colorful and brilliant!
aristotleQuote := "The more you know, the more you realize you don't know."
emphasized := marker.Mark(aristotleQuote, marker.MatchAll("know"), color.New(color.FgRed))
fmt.Println(emphasized)
You may want to instrument a logger such that any output coming from it is colorized in the expected manner. marker contains functionality which can be easily integrated with Golang's log or any interface that supports io.Writer.
stdoutMarker := marker.NewStdoutMarker()
markRules := []marker.MarkRule{
{marker.MatchBracketSurrounded(), color.New(color.FgBlue)},
{marker.MatchAll("marker"), color.New(color.FgRed)},
}
stdoutMarker.AddRules(markRules)
logger := log.New(stdoutMarker, "", 0)
logger.Println("[INFO] marker is working as expected")
marker also allows you to specify the io.Writer that you want to send output to. This is useful if the logger is writing to somewhere other than stdout like a file.
f, _ := os.Create("/tmp/awesome.log")
w := bufio.NewWriter(f)
writeMarker := marker.NewWriteMarker(w)
markRules := []marker.MarkRule{
{marker.MatchBracketSurrounded(), blueFg},
{marker.MatchAll("marker"), magentaFg},
}
writeMarker.AddRules(markRules)
logger := log.New(writeMarker, "", 0)
logger.Println("[INFO] colorful logs even in files, marker to mark them all!")
w.Flush()
f.Close()
output := catFile("/tmp/awesome.log") // $ cat /tmp/awesome.log
fmt.Print(output)
aristotleQuote := "The more you know, the more you realize you don't know."
emphasized := marker.Mark(aristotleQuote, marker.MatchAll("know"), color.New(color.FgRed))
fmt.Println(emphasized)
boringLog := "[INFO] Nobody wants to read pale [INFO] tags."
brilliantLog := marker.Mark(boringLog, marker.MatchN("[INFO]", 1), color.New(color.FgBlue))
fmt.Println(brilliantLog)
rhyme := "I scream, you all scream, we all scream for ice cream."
r, _ := regexp.Compile("([a-z]?cream)")
careAboutCream := marker.Mark(rhyme, marker.MatchRegexp(r), color.New(color.FgYellow))
fmt.Println(careAboutCream)
sentence := "I pull out things surrounded by abcWHOA COLORSdef"
markedSurrounded := marker.Mark(sentence, marker.MatchSurrounded("abc", "def"), color.New(color.FgMagenta))
fmt.Println(markedSurrounded)
sentence = "[INFO] This is what log lines look like"
markedSurrounded = marker.Mark(sentence, marker.MatchBracketSurrounded(), color.New(color.FgRed))
fmt.Println(markedSurrounded)
sentence = "[ERROR] This is what (parens) lines look like"
markedSurrounded = marker.Mark(sentence, marker.MatchParensSurrounded(), color.New(color.FgBlue))
fmt.Println(markedSurrounded)
MatchTimestamp can be used for matching the timestamps fits the layouts in Golang's time.
All possible formats can be found here.
goodOldTimes := "2006-01-02T15:04:05Z07:00 [INFO] Loading King of Fighters '97 ROM"
timestampMarked := marker.Mark(goodOldTimes, marker.MatchTimestamp(time.RFC3339), color.New(color.FgBlue))
fmt.Println(timestampMarked)
If you want to mark different patterns in the same string, marker builder is neater way to do this.
rhyme := "I scream, you all scream, we all scream for ice cream."
b := &marker.MarkBuilder{}
r, _ := regexp.Compile("([a-z]?cream)")
markedWithBuilder := b.SetString(rhyme).
Mark(marker.MatchN("for ice", 1), color.New(color.FgRed)).
Mark(marker.MatchAll("all"), color.New(color.FgMagenta)).
Mark(marker.MatchRegexp(r), color.New(color.FgYellow)).
Build()
fmt.Println(markedWithBuilder)
As you see in above examples, Mark function takes an MatcherFunc to match the patterns in given string and colorize them. A Matcher is a simple closure that returns a MatcherFunc to be called by Mark function to get Match information to put colorized versions of patterns into template.
Lets write our own custom Matcher that matches first encounter of given pattern.
func MatchFirst(pattern string) marker.MatcherFunc {
return func(str string) marker.Match {
return marker.Match{
// replace first matching pattern with %s
Template: strings.Replace(str, pattern, "%s", 1),
// patterns to be colorized by Mark, in order
Patterns: []string{pattern},
}
}
}You can also check built-in matchers for inspiration.
I would like to accept any contributions to make Marker better and feature rich. So feel free to contribute your features(i.e. more Matchers!), improvements and fixes.