dd: simplify match

src/uu/dd/src/dd.rs

@@ -684,22 +684,20 @@ impl Dest {
 
     /// Truncate the underlying file to the current stream position, if possible.
     fn truncate(&mut self) -> io::Result<()> {
-        #[allow(clippy::match_wildcard_for_single_variants)]
-        match self {
-            Self::File(f, _) => {
-                let pos = f.stream_position()?;
-                // `set_len()` can fail with EINVAL on special outputs such as
-                // `/dev/null`; GNU `dd` ignores that. But on a regular file a
-                // truncate failure (e.g. ENOSPC, read-only fs) means silent data
-                // loss, so the error must surface there.
-                match f.set_len(pos) {
-                    Ok(()) => Ok(()),
-                    Err(e) if f.metadata().is_ok_and(|m| m.file_type().is_file()) => Err(e),
-                    Err(_) => Ok(()),
-                }
-            }
-            _ => Ok(()),
+        let Self::File(f, _) = self else {
+            return Ok(());
+        };
+        let pos = f.stream_position()?;
+        // `set_len()` can fail with EINVAL on special outputs such as
+        // `/dev/null`; GNU ignores that. But on a regular file a
+        // truncate failure (e.g. ENOSPC, read-only fs) means silent data
+        // loss.
+        if let Err(e) = f.set_len(pos)
+            && f.metadata().is_ok_and(|m| m.file_type().is_file())
+        {
+            return Err(e);
         }
+        Ok(())
     }
 
     /// Discard the system file cache for the given portion of the destination.
@@ -1281,18 +1279,13 @@ fn dd_copy(mut i: Input, o: Output) -> io::Result<()> {
         if check_and_reset_sigusr1() {
             alarm.manual_trigger();
         }
-        match alarm.get_trigger() {
-            ALARM_TRIGGER_NONE => {}
-            t @ (ALARM_TRIGGER_TIMER | ALARM_TRIGGER_SIGNAL) => {
-                let tp = match t {
-                    ALARM_TRIGGER_TIMER => ProgUpdateType::Periodic,
-                    _ => ProgUpdateType::Signal,
-                };
-                let prog_update = ProgUpdate::new(rstat, wstat, start.elapsed(), tp);
-                prog_tx.send(prog_update).unwrap_or(());
-            }
-            _ => {}
-        }
+        let tp = match alarm.get_trigger() {
+            ALARM_TRIGGER_TIMER => ProgUpdateType::Periodic,
+            ALARM_TRIGGER_SIGNAL => ProgUpdateType::Signal,
+            _ => continue,
+        };
+        let prog_update = ProgUpdate::new(rstat, wstat, start.elapsed(), tp);
+        prog_tx.send(prog_update).unwrap_or(());
     }
 
     finalize(o, rstat, wstat, start, &prog_tx, output_thread, truncate)