refactor arg handling

src/main.rs

@@ -25,16 +25,21 @@ fn become_wm<C: Connection>(conn: &C, screen: &Screen) -> anyhow::Result<()> {
     res.map_err(|e| anyhow!(e))
 }
 
-fn main() -> anyhow::Result<()> {
+fn handle_args() {
     let mut args = std::env::args().skip(1);
     if let Some(arg) = args.next() {
         if arg != "-v" {
-            return Err(anyhow!("usage: rswm [-v]"));
+            eprintln!("usage: rswm [-v]");
+            exit(1);
         } else {
             println!("rswm-{}", env!("CARGO_PKG_VERSION"));
-            return Ok(());
+            exit(0);
         }
     }
+}
+
+fn main() -> anyhow::Result<()> {
+    handle_args();
 
     // TODO: Investigate LC_CTYPE and Locale stuff from dwm