docs: document astyle in HACKING.md

diff --git a/HACKING.md b/HACKING.md
index b8aed6125a94e43d92dfc6e93abd167d6e537815..d0969b8b83299a72e1cfd4421f37488a83f6d7b7 100644 (file)
--- a/HACKING.md
+++ b/HACKING.md
@@ -14,12 +14,12 @@ Pull requests should be filed preferably on github nowadays.
 It is recommended, that you install a plugin for your editor, which reads in `.editorconfig`.
 Additionally `emacs` and `vim` config files are provided for convenience.
 
-To reformat C files use `indent`:
+To reformat C files use `astyle`:
 ```console
-$ indent -i8 -nut -br -linux -l120 <FILE>
+$ astyle --options=.astylerc <FILE>
 ```
 
-For convenience there is also a Makefile `indent` target `make indent`.
+For convenience there is also a Makefile `indent-c` target `make indent-c`.
 
 To reformat shell files use `shfmt`:
 
@@ -30,6 +30,8 @@ $ chmod u+x shfmt
 $ ./shfmt -w -s .
 ```
 
+or if `shfmt` is already in your `PATH`, use `make indent`.
+
 Some IDEs already have support for shfmt.
 
 For convenience the `make indent` Makefile target also calls shfmt, if it is in `$PATH`.