Avoid shell backticks and improve md5sum.ml error messages

Author: kit-ty-kate

Makefile.checker

@@ -77,8 +77,8 @@ checker/%.cmx: checker/%.ml
 
 md5chk:
 	$(SHOW)'MD5SUM cic.mli'
-	$(HIDE)if grep -q "^MD5 `$(OCAML) tools/md5sum.ml checker/cic.mli`$$" checker/values.ml; \
-	       then true; else echo "Error: outdated checker/values.ml"; false; fi
+	$(HIDE)if grep -q "^MD5 $$($(OCAML) tools/md5sum.ml checker/cic.mli)$$" checker/values.ml; \
+	       then true; else echo "Error: outdated checker/values.ml" >&2; false; fi
 
 .PHONY: md5chk
 

tools/md5sum.ml

@@ -7,8 +7,9 @@ let get_content file =
                          git checkout has included return characters.
                          See: https://github.com/coq/coq/pull/6305 *)
     | c -> Buffer.add_char buf c; fill ()
+    | exception End_of_file -> close_in ic; Buffer.contents buf
   in
-  try fill () with End_of_file -> Buffer.contents buf
+  fill ()
 
 let () =
   match Sys.argv with
@@ -18,6 +19,6 @@ let () =
       print_string (md5 ^ " " ^ file)
   | _ ->
       prerr_endline "Error: This program needs exactly one parameter.";
-      prerr_endline "Usage: ocaml md5sum.ml [FILE]";
-      prerr_endline "Print MD5 (128-bit) checksum.";
+      prerr_endline "Usage: ocaml md5sum.ml <FILE>";
+      prerr_endline "Print MD5 (128-bit) checksum of the file content modulo \\r.";
       exit 1