solar: use grammar file from command line

1 files changed, 7 insertions, 2 deletions

diff --git a/src/solar.cpp b/src/solar.cpp
index e0fbba0..c022a6d 100644
--- a/src/solar.cpp
+++ b/src/solar.cpp
@@ -74,11 +74,16 @@ bool read_grammar(const char *filename, parser_state_t *state) {
 }
 
 
-int main() {
+int main(int argc, char *argv[]) {
 	using namespace solar;
 
+	if (argc < 2) {
+		std::fprintf(stderr, "Usage: solar FILE\n");
+		return 1;
+	}
+
 	parser_state_t state;
-	if (!read_grammar("grammar.y", &state))
+	if (!read_grammar(argv[1], &state))
 		return 1;
 
 	generator_t generator(state.get_rules());