Add os exit utilities

pkg/util/exit/exit.go

+package exit
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/tmrts/tmplt/pkg/util/tlog"
+)
+
+const (
+	CodeOK    = 0
+	CodeError = 2
+)
+
+func Error(err error) {
+	tlog.Error(fmt.Sprint(err))
+
+	os.Exit(CodeError)
+}
+
+func OK(msg string) {
+	os.Exit(CodeOK)
+}

pkg/util/osutil/file.go → pkg/util/osutil/fs.go

@@ -10,3 +10,12 @@ func FileExists(filename string) error {
 
 	return nil
 }
+
+func DirExists(dirname string) error {
+	_, err := os.Stat(dirname)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}