check for args length

jamorton · Apr 7, 2012 · e2089a9 · e2089a9
1 parent b73d4f4
commit e2089a9
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/asm.rs b/asm.rs
@@ -251,6 +251,11 @@ fn compile_file(filename: str)
 }
 
 fn main(args: [str]) {
-    compile_file(args[1]);
+    if (arg.len() != 2) {
+        io::println("Usage:");
+        io::println("  ./asm [asm file]");
+        ret;
+    }
 
+    compile_file(args[1]);
 }