Fix some clippy warnings

src/uu/cat/src/cat.rs

@@ -192,7 +192,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         NumberingMode::None
     };
 
-    let show_nonprint = vec![
+    let show_nonprint = [
         options::SHOW_ALL.to_owned(),
         options::SHOW_NONPRINTING_ENDS.to_owned(),
         options::SHOW_NONPRINTING_TABS.to_owned(),
@@ -201,7 +201,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     .iter()
     .any(|v| matches.get_flag(v));
 
-    let show_ends = vec![
+    let show_ends = [
         options::SHOW_ENDS.to_owned(),
         options::SHOW_ALL.to_owned(),
         options::SHOW_NONPRINTING_ENDS.to_owned(),
@@ -209,7 +209,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     .iter()
     .any(|v| matches.get_flag(v));
 
-    let show_tabs = vec![
+    let show_tabs = [
         options::SHOW_ALL.to_owned(),
         options::SHOW_TABS.to_owned(),
         options::SHOW_NONPRINTING_TABS.to_owned(),

src/uu/chmod/src/chmod.rs

@@ -438,25 +438,25 @@ mod tests {
     fn test_extract_negative_modes() {
         // "chmod -w -r file" becomes "chmod -w,-r file". clap does not accept "-w,-r" as MODE.
         // Therefore, "w" is added as pseudo mode to pass clap.
-        let (c, a) = extract_negative_modes(vec!["-w", "-r", "file"].iter().map(OsString::from));
+        let (c, a) = extract_negative_modes(["-w", "-r", "file"].iter().map(OsString::from));
         assert_eq!(c, Some("-w,-r".to_string()));
-        assert_eq!(a, vec!["w", "file"]);
+        assert_eq!(a, ["w", "file"]);
 
         // "chmod -w file -r" becomes "chmod -w,-r file". clap does not accept "-w,-r" as MODE.
         // Therefore, "w" is added as pseudo mode to pass clap.
-        let (c, a) = extract_negative_modes(vec!["-w", "file", "-r"].iter().map(OsString::from));
+        let (c, a) = extract_negative_modes(["-w", "file", "-r"].iter().map(OsString::from));
         assert_eq!(c, Some("-w,-r".to_string()));
-        assert_eq!(a, vec!["w", "file"]);
+        assert_eq!(a, ["w", "file"]);
 
         // "chmod -w -- -r file" becomes "chmod -w -r file", where "-r" is interpreted as file.
         // Again, "w" is needed as pseudo mode.
-        let (c, a) = extract_negative_modes(vec!["-w", "--", "-r", "f"].iter().map(OsString::from));
+        let (c, a) = extract_negative_modes(["-w", "--", "-r", "f"].iter().map(OsString::from));
         assert_eq!(c, Some("-w".to_string()));
-        assert_eq!(a, vec!["w", "--", "-r", "f"]);
+        assert_eq!(a, ["w", "--", "-r", "f"]);
 
         // "chmod -- -r file" becomes "chmod -r file".
-        let (c, a) = extract_negative_modes(vec!["--", "-r", "file"].iter().map(OsString::from));
+        let (c, a) = extract_negative_modes(["--", "-r", "file"].iter().map(OsString::from));
         assert_eq!(c, None);
-        assert_eq!(a, vec!["--", "-r", "file"]);
+        assert_eq!(a, ["--", "-r", "file"]);
     }
 }

src/uu/dircolors/src/dircolors.rs

@@ -168,9 +168,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
             println!("{s}");
             Ok(())
         }
-        Err(s) => {
+        Err(s) => Err(USimpleError::new(1, s)),
-            return Err(USimpleError::new(1, s));
-        }
     }
 }
 

src/uu/id/src/id.rs

@@ -550,7 +550,7 @@ fn auditid() {
     println!("asid={}", auditinfo.ai_asid);
 }
 
-fn id_print(state: &mut State, groups: &[u32]) {
+fn id_print(state: &State, groups: &[u32]) {
     let uid = state.ids.as_ref().unwrap().uid;
     let gid = state.ids.as_ref().unwrap().gid;
     let euid = state.ids.as_ref().unwrap().euid;

src/uu/install/src/install.rs

@@ -619,7 +619,7 @@ fn copy_files_into_dir(files: &[PathBuf], target_dir: &Path, b: &Behavior) -> UR
     if !target_dir.is_dir() {
         return Err(InstallError::TargetDirIsntDir(target_dir.to_path_buf()).into());
     }
-    for sourcepath in files.iter() {
+    for sourcepath in files {
         if let Err(err) = sourcepath
             .metadata()
             .map_err_context(|| format!("cannot stat {}", sourcepath.quote()))

src/uu/mknod/src/mknod.rs

@@ -101,12 +101,10 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
             matches.get_one::<u64>("major"),
             matches.get_one::<u64>("minor"),
         ) {
-            (_, None) | (None, _) => {
+            (_, None) | (None, _) => Err(UUsageError::new(
-                return Err(UUsageError::new(
+                1,
-                    1,
+                "Special files require major and minor device numbers.",
-                    "Special files require major and minor device numbers.",
+            )),
-                ));
-            }
             (Some(&major), Some(&minor)) => {
                 let dev = makedev(major, minor);
                 let exit_code = match file_type {

src/uu/mv/src/mv.rs

@@ -364,7 +364,7 @@ fn move_files_into_dir(files: &[PathBuf], target_dir: &Path, b: &Behavior) -> UR
         None
     };
 
-    for sourcepath in files.iter() {
+    for sourcepath in files {
         if let Some(ref pb) = count_progress {
             pb.set_message(sourcepath.to_string_lossy().to_string());
         }

src/uu/od/src/prn_char.rs

@@ -82,7 +82,7 @@ pub fn format_ascii_dump(bytes: &[u8]) -> String {
     let mut result = String::new();
 
     result.push('>');
-    for c in bytes.iter() {
+    for c in bytes {
         if *c >= 0x20 && *c <= 0x7e {
             result.push_str(C_CHARS[*c as usize]);
         } else {

src/uu/sort/src/check.rs

@@ -54,7 +54,7 @@ pub fn check(path: &OsStr, settings: &GlobalSettings) -> UResult<()> {
 
     let mut prev_chunk: Option<Chunk> = None;
     let mut line_idx = 0;
-    for chunk in loaded_receiver.iter() {
+    for chunk in loaded_receiver {
         line_idx += 1;
         if let Some(prev_chunk) = prev_chunk.take() {
             // Check if the first element of the new chunk is greater than the last
@@ -107,7 +107,7 @@ fn reader(
     settings: &GlobalSettings,
 ) -> UResult<()> {
     let mut carry_over = vec![];
-    for recycled_chunk in receiver.iter() {
+    for recycled_chunk in receiver {
         let should_continue = chunks::read(
             sender,
             recycled_chunk,

src/uu/sort/src/merge.rs

@@ -211,7 +211,7 @@ fn reader(
     settings: &GlobalSettings,
     separator: u8,
 ) -> UResult<()> {
-    for (file_idx, recycled_chunk) in recycled_receiver.iter() {
+    for (file_idx, recycled_chunk) in recycled_receiver {
         if let Some(ReaderFile {
             file,
             sender,

src/uu/stdbuf/src/stdbuf.rs

@@ -130,7 +130,7 @@ fn set_command_env(command: &mut process::Command, buffer_name: &str, buffer_typ
     }
 }
 
-fn get_preload_env(tmp_dir: &mut TempDir) -> io::Result<(String, PathBuf)> {
+fn get_preload_env(tmp_dir: &TempDir) -> io::Result<(String, PathBuf)> {
     let (preload, extension) = preload_strings();
     let inject_path = tmp_dir.path().join("libstdbuf").with_extension(extension);
 

src/uu/sum/src/sum.rs

@@ -33,7 +33,7 @@ fn bsd_sum(mut reader: Box<dyn Read>) -> (usize, u16) {
         match reader.read(&mut buf) {
             Ok(n) if n != 0 => {
                 bytes_read += n;
-                for &byte in buf[..n].iter() {
+                for &byte in &buf[..n] {
                     checksum = checksum.rotate_right(1);
                     checksum = checksum.wrapping_add(u16::from(byte));
                 }
@@ -56,7 +56,7 @@ fn sysv_sum(mut reader: Box<dyn Read>) -> (usize, u16) {
         match reader.read(&mut buf) {
             Ok(n) if n != 0 => {
                 bytes_read += n;
-                for &byte in buf[..n].iter() {
+                for &byte in &buf[..n] {
                     ret = ret.wrapping_add(u32::from(byte));
                 }
             }

src/uu/sync/src/sync.rs

@@ -173,7 +173,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
             let path = Path::new(&f);
             if let Err(e) = open(path, OFlag::O_NONBLOCK, Mode::empty()) {
                 if e != Errno::EACCES || (e == Errno::EACCES && path.is_dir()) {
-                    return e.map_err_context(|| format!("error opening {}", f.quote()))?;
+                    e.map_err_context(|| format!("error opening {}", f.quote()))?;
                 }
             }
         }

src/uu/tail/src/chunks.rs

@@ -495,7 +495,7 @@ impl LinesChunk {
     fn calculate_bytes_offset_from(&self, offset: usize) -> usize {
         let mut lines_offset = offset;
         let mut bytes_offset = 0;
-        for byte in self.get_buffer().iter() {
+        for byte in self.get_buffer() {
             if lines_offset == 0 {
                 break;
             }

src/uu/wc/src/wc.rs

@@ -686,7 +686,7 @@ fn compute_number_width(inputs: &Inputs, settings: &Settings) -> usize {
 
             let mut minimum_width = 1;
             let mut total: u64 = 0;
-            for input in inputs.iter() {
+            for input in inputs {
                 match input {
                     Input::Stdin(_) => minimum_width = MINIMUM_WIDTH,
                     Input::Path(path) => {

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

@@ -845,7 +845,7 @@ mod tests {
         let path1 = temp_file.path();
         let path2 = temp_file.path();
 
-        assert_eq!(are_hardlinks_to_same_file(&path1, &path2), true);
+        assert!(are_hardlinks_to_same_file(&path1, &path2));
     }
 
     #[cfg(unix)]
@@ -860,7 +860,7 @@ mod tests {
         let path1 = temp_file1.path();
         let path2 = temp_file2.path();
 
-        assert_eq!(are_hardlinks_to_same_file(&path1, &path2), false);
+        assert!(are_hardlinks_to_same_file(&path1, &path2));
     }
 
     #[cfg(unix)]
@@ -873,6 +873,6 @@ mod tests {
         let path2 = temp_file.path().with_extension("hardlink");
         fs::hard_link(&path1, &path2).unwrap();
 
-        assert_eq!(are_hardlinks_to_same_file(&path1, &path2), true);
+        assert!(are_hardlinks_to_same_file(&path1, &path2));
     }
 }

tests/by-util/test_cp.rs

@@ -2022,12 +2022,12 @@ fn test_cp_reflink_always_override() {
     const USERDIR: &str = "dir/";
     const MOUNTPOINT: &str = "mountpoint/";
 
-    let src1_path: &str = &vec![MOUNTPOINT, USERDIR, "src1"].concat();
+    let src1_path: &str = &[MOUNTPOINT, USERDIR, "src1"].concat();
-    let src2_path: &str = &vec![MOUNTPOINT, USERDIR, "src2"].concat();
+    let src2_path: &str = &[MOUNTPOINT, USERDIR, "src2"].concat();
-    let dst_path: &str = &vec![MOUNTPOINT, USERDIR, "dst"].concat();
+    let dst_path: &str = &[MOUNTPOINT, USERDIR, "dst"].concat();
 
     scene.fixtures.mkdir(ROOTDIR);
-    scene.fixtures.mkdir(vec![ROOTDIR, USERDIR].concat());
+    scene.fixtures.mkdir([ROOTDIR, USERDIR].concat());
 
     // Setup:
     // Because neither `mkfs.btrfs` not btrfs `mount` options allow us to have a mountpoint owned

tests/by-util/test_factor.rs

@@ -173,7 +173,6 @@ fn test_random() {
                     break;
                 }
             }
-            let factor = factor;
 
             match product.checked_mul(factor) {
                 Some(p) => {
@@ -317,7 +316,7 @@ fn run(input_string: &[u8], output_string: &[u8]) {
 fn test_primes_with_exponents() {
     let mut input_string = String::new();
     let mut output_string = String::new();
-    for primes in PRIMES_BY_BITS.iter() {
+    for primes in PRIMES_BY_BITS {
         for &prime in *primes {
             input_string.push_str(&(format!("{prime} "))[..]);
             output_string.push_str(&(format!("{prime}: {prime}\n"))[..]);

tests/by-util/test_link.rs

@@ -58,7 +58,7 @@ fn test_link_one_argument() {
 #[test]
 fn test_link_three_arguments() {
     let (_, mut ucmd) = at_and_ucmd!();
-    let arguments = vec![
+    let arguments = [
         "test_link_argument1",
         "test_link_argument2",
         "test_link_argument3",

tests/by-util/test_mv.rs

@@ -1278,7 +1278,7 @@ fn test_mv_verbose() {
 
 #[test]
 #[cfg(any(target_os = "linux", target_os = "android"))] // mkdir does not support -m on windows. Freebsd doesn't return a permission error either.
-#[cfg(features = "mkdir")]
+#[cfg(feature = "mkdir")]
 fn test_mv_permission_error() {
     let scene = TestScenario::new("mkdir");
     let folder1 = "bar";

tests/by-util/test_rm.rs

@@ -478,7 +478,7 @@ fn test_rm_prompts() {
     // Needed for talking with stdin on platforms where CRLF or LF matters
     const END_OF_LINE: &str = if cfg!(windows) { "\r\n" } else { "\n" };
 
-    let mut answers = vec![
+    let mut answers = [
         "rm: descend into directory 'a'?",
         "rm: remove write-protected regular empty file 'a/empty-no-write'?",
         "rm: remove symbolic link 'a/slink'?",

tests/by-util/test_shuf.rs

@@ -71,7 +71,7 @@ fn test_echo() {
 #[test]
 fn test_head_count() {
     let repeat_limit = 5;
-    let input_seq = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+    let input_seq = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
     let input = input_seq
         .iter()
         .map(ToString::to_string)
@@ -102,7 +102,7 @@ fn test_head_count() {
 #[test]
 fn test_repeat() {
     let repeat_limit = 15000;
-    let input_seq = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+    let input_seq = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
     let input = input_seq
         .iter()
         .map(ToString::to_string)

tests/common/util.rs

@@ -541,7 +541,7 @@ impl CmdResult {
         let contents = String::from_utf8(read_scenario_fixture(&self.tmpd, file_rel_path)).unwrap();
         let possible_values = template_vars.iter().map(|vars| {
             let mut contents = contents.clone();
-            for kv in vars.iter() {
+            for kv in vars {
                 contents = contents.replace(&kv.0, &kv.1);
             }
             contents
@@ -2211,12 +2211,12 @@ impl UChild {
         let join_handle = thread::spawn(move || {
             let mut writer = BufWriter::new(stdin);
 
-            match writer.write_all(&content).and_then(|_| writer.flush()) {
+            match writer.write_all(&content).and_then(|()| writer.flush()) {
                 Err(error) if !ignore_stdin_write_error => Err(io::Error::new(
                     io::ErrorKind::Other,
                     format!("failed to write to stdin of child: {error}"),
                 )),
-                Ok(_) | Err(_) => Ok(()),
+                Ok(()) | Err(_) => Ok(()),
             }
         });
 
@@ -2263,12 +2263,12 @@ impl UChild {
     pub fn try_write_in<T: Into<Vec<u8>>>(&mut self, data: T) -> io::Result<()> {
         let stdin = self.raw.stdin.as_mut().unwrap();
 
-        match stdin.write_all(&data.into()).and_then(|_| stdin.flush()) {
+        match stdin.write_all(&data.into()).and_then(|()| stdin.flush()) {
             Err(error) if !self.ignore_stdin_write_error => Err(io::Error::new(
                 io::ErrorKind::Other,
                 format!("failed to write to stdin of child: {error}"),
             )),
-            Ok(_) | Err(_) => Ok(()),
+            Ok(()) | Err(_) => Ok(()),
         }
     }
 
@@ -2505,11 +2505,11 @@ pub fn expected_result(ts: &TestScenario, args: &[&str]) -> std::result::Result<
 
 /// This is a convenience wrapper to run a ucmd with root permissions.
 /// It can be used to test programs when being root is needed
-/// This runs 'sudo -E --non-interactive target/debug/coreutils util_name args`
+/// This runs `sudo -E --non-interactive target/debug/coreutils util_name args`
 /// This is primarily designed to run in an environment where whoami is in $path
 /// and where non-interactive sudo is possible.
 /// To check if i) non-interactive sudo is possible and ii) if sudo works, this runs:
-/// 'sudo -E --non-interactive whoami' first.
+/// `sudo -E --non-interactive whoami` first.
 ///
 /// This return an `Err()` if run inside CICD because there's no 'sudo'.
 ///
@@ -3279,7 +3279,7 @@ mod tests {
                 std::assert_eq!(error.to_string(), "kill: Timeout of '0s' reached");
             }
             Err(error) => panic!("Assertion failed: Expected error with timeout but was: {error}"),
-            Ok(_) => panic!("Assertion failed: Expected timeout of `try_kill`."),
+            Ok(()) => panic!("Assertion failed: Expected timeout of `try_kill`."),
         }
     }