feat: add conditional signal handler for Redox OS compatibility

Make the ctrlc dependency and signal handler optional for Redox OS, which lacks signal support. Added cfg attributes to skip signal handling on Redox, preventing compilation errors. Also added clippy allow attributes for FreeBSD in fs.rs.

Author: mattsu2020

src/uu/sort/Cargo.toml

@@ -24,7 +24,6 @@ bigdecimal = { workspace = true }
 binary-heap-plus = { workspace = true }
 clap = { workspace = true }
 compare = { workspace = true }
-ctrlc = { workspace = true }
 fnv = { workspace = true }
 itertools = { workspace = true }
 memchr = { workspace = true }
@@ -37,6 +36,9 @@ unicode-width = { workspace = true }
 uucore = { workspace = true, features = ["fs", "parser-size", "version-cmp"] }
 fluent = { workspace = true }
 
+[target.'cfg(not(target_os = "redox"))'.dependencies]
+ctrlc = { workspace = true }
+
 [target.'cfg(unix)'.dependencies]
 nix = { workspace = true, features = ["resource"] }
 

src/uu/sort/src/tmp_dir.rs

@@ -55,6 +55,7 @@ fn should_install_signal_handler() -> bool {
     open_fds.saturating_add(CTRL_C_FDS + RESERVED_FOR_MERGE) <= limit
 }
 
+#[cfg(not(target_os = "redox"))]
 fn ensure_signal_handler_installed(state: Arc<Mutex<HandlerRegistration>>) -> UResult<()> {
     // This shared state must originate from `handler_state()` so the handler always sees
     // the current lock/path pair and can clean up the active temp directory on SIGINT.
@@ -104,6 +105,11 @@ fn ensure_signal_handler_installed(state: Arc<Mutex<HandlerRegistration>>) -> UR
     Ok(())
 }
 
+#[cfg(target_os = "redox")]
+fn ensure_signal_handler_installed(_state: Arc<Mutex<HandlerRegistration>>) -> UResult<()> {
+    Ok(())
+}
+
 impl TmpDirWrapper {
     pub fn new(path: PathBuf) -> Self {
         Self {

src/uucore/src/lib/features/fs.rs

@@ -149,6 +149,7 @@ impl FileInformation {
                 not(target_pointer_width = "64")
             )
         ))]
+        #[cfg_attr(target_os = "freebsd", allow(clippy::useless_conversion))]
         return self.0.st_nlink.into();
         #[cfg(target_os = "aix")]
         return self.0.st_nlink.try_into().unwrap();
@@ -168,6 +169,7 @@ impl FileInformation {
             target_os = "netbsd",
             not(target_pointer_width = "64")
         ))]
+        #[cfg_attr(target_os = "freebsd", allow(clippy::useless_conversion))]
         return self.0.st_ino.into();
     }
 }