-f file

main.go

@@ -53,10 +53,10 @@ type LineMatch struct {
 const (
 	reset = "\x1b[0m"
 
-	bold   = "\x1b[1m"
-	red    = "\x1b[31m"
-	green  = "\x1b[32m"
-	yellow = "\x1b[33m"
+	//bold   = "\x1b[1m"
+	//red    = "\x1b[31m"
+	green = "\x1b[32m"
+	//yellow = "\x1b[33m"
 )
 
 func highlight(src string, start, end int, style ...string) string {
@@ -333,11 +333,23 @@ func processReader(r *os.File, pattern string, exp bool) []LineMatch {
 func main() {
 	regexModePtr := flag.Bool("ex", false, "set if using g2eb expressions, leave for full string matching")
 	noHighlightPtr := flag.Bool("noh", false, "no hightlght")
+	filePtr := flag.String("f", "", "specify a file path to read file instead of stdin")
 
 	flag.Parse()
 
 	pattern := flag.Args()[0]
-	m := processReader(os.Stdin, pattern, *regexModePtr)
+	var in *os.File
+	if *filePtr != "" {
+		f, err := os.Open(*filePtr)
+		if err != nil {
+			_ = fmt.Errorf("Could not open file %s", *filePtr)
+			os.Exit(-1)
+		}
+		in = f
+	} else {
+		in = os.Stdin
+	}
+	m := processReader(in, pattern, *regexModePtr)
 
 	for _, lm := range m {
 		if *noHighlightPtr {