--- a/sysex2smf.cpp	Tue May 19 22:56:20 2020 +0200
+++ b/sysex2smf.cpp	Tue May 19 23:09:10 2020 +0200
@@ -18,7 +18,22 @@
 #include <sstream>
 #include <smf.h>
 
+/**
+ * Translates System Exclusive (SysEx) message (binary not HEX) from standard input to a Standard MIDI file (SMF).
+ * The file path must be passed as a CLI argument.
+ * 
+ * Usage examples:
+ *     cat test.syx | ./sysex2smf test.mid
+ * 
+ * Dependencies:
+ *     libsmf (in Debian-based distributions do: apt install libsmf-dev)
+ * 
+ * @param argc
+ * @param argv
+ * @return 
+ */
 int main(int argc, char**argv) {
+	int exitCode = 0;
 	if (argc == 2) {
 		smf_t* smf = smf_new();
 		smf_track_t* track = smf_track_new();
@@ -29,14 +44,20 @@
 			data.put(ch);
 		}
 
+		// TODO: review the (void*) – it works but…
 		smf_event_t* event = smf_event_new_from_pointer((void*) data.str().c_str(), data.tellp());
 		smf_track_add_event_pulses(track, event, 0);
 
-
+		// TODO: check whether file exists?
 		int res = smf_save(smf, argv[1]);
-		if (res) std::cerr << "unable to save MIDI file: " << res << std::endl;
+		if (res) {
+			std::cerr << "Error: Unable to save MIDI file: " << argv[1] << " Error code: " << res << std::endl;
+			exitCode = 1;
+		}
 		smf_delete(smf);
 	} else {
 		std::cerr << "Usage: " << argv[0] << " 'output-file.mid'" << std::endl;
+		exitCode = 1;
 	}
+	return exitCode;
 }