wip: debugging issue

README.md

@@ -27,7 +27,12 @@ simple-privacy-tool decrypt cryptedfile plainfile
 ```
 
 #### Using STDIN/STDOUT
-`simple-privacy-tool` can operate on `STDOUT`. Just replace the file path with `-`
+`simple-privacy-tool` can operate on `STDIN` or `STDOUT`. Just replace the file path with `-`
 ```shell
-simple-privacy-tool encrypt srcFile - | another-command
+tar -zcf - dir | simple-privacy-tool encrypt - - | another-command
+```
+
+Special usage, just omit both file paths to use `STDIN` and `STDOUT`.
+```shell
+tar -zcf - dir | simple-privacy-tool encrypt | another-command
 ```