cmd/grepfunc: add verbose mode

Print gogrep pattern if verbose mode is on.

Signed-off-by: Iskander Sharipov <[email protected]>

cmd/grepfunc/main.go

@@ -21,6 +21,8 @@ func main() {
 		`input Go file with pattern function`)
 	pattern := flag.String("pattern", "_pattern",
 		`function to be interpreted as a pattern`)
+	verbose := flag.Bool("v", false,
+		`turn on debug output`)
 	flag.Parse()
 
 	if *input == "" {
@@ -52,6 +54,10 @@ func main() {
 	s = strings.TrimPrefix(s, "{")
 	s = strings.TrimSuffix(s, "}")
 
+	if *verbose {
+		fmt.Println(s)
+	}
+
 	gogrepArgs := []string{"-x", s}
 	gogrepArgs = append(gogrepArgs, targets...)
 	out, err := exec.Command("gogrep", gogrepArgs...).CombinedOutput()