Draft to create a parallel grep using channel

gogrep.go

// Go grep parallel
// https://golang.hotexamples.com/examples/codesearch.regexp/Grep/File/golang-grep-file-method-examples.html

func main() {
	var g regexp.Grep
	g.AddFlags()
	g.Stdout = os.Stdout
	g.Stderr = os.Stderr
	flag.Usage = usage
	flag.Parse()
	args := flag.Args()
	if len(args) == 0 {
		flag.Usage()
	}

	if *cpuProfile != "" {
		f, err := os.Create(*cpuProfile)
		if err != nil {
			log.Fatal(err)
		}
		defer f.Close()
		pprof.StartCPUProfile(f)
		defer pprof.StopCPUProfile()
	}

	pat := "(?m)" + args[0]
	if *iflag {
		pat = "(?i)" + pat
	}
	re, err := regexp.Compile(pat)
	if err != nil {
		log.Fatal(err)
	}
	g.Regexp = re
	if len(args) == 1 {
		g.Reader(os.Stdin, "<standard input>")
	} else {
		for _, arg := range args[1:] {
			g.File(arg)
		}
	}
	if !g.Match {
		os.Exit(1)
	}
}