fix a lot of clippy warnings

src/uu/basename/src/basename.rs

@@ -136,7 +136,8 @@ fn basename(fullname: &str, suffix: &str) -> String {
     }
 }
 
-// can be replaced with strip_suffix once the minimum rust version is 1.45
+// can be replaced with strip_suffix once MSRV is 1.45
+#[allow(clippy::manual_strip)]
 fn strip_suffix(name: &str, suffix: &str) -> String {
     if name == suffix {
         return name.to_owned();

src/uu/cp/src/cp.rs

@@ -1108,7 +1108,7 @@ fn context_for(src: &Path, dest: &Path) -> String {
 
 /// Implements a simple backup copy for the destination file.
 /// TODO: for the backup, should this function be replaced by `copy_file(...)`?
-fn backup_dest(dest: &Path, backup_path: &PathBuf) -> CopyResult<PathBuf> {
+fn backup_dest(dest: &Path, backup_path: &Path) -> CopyResult<PathBuf> {
     fs::copy(dest, &backup_path)?;
     Ok(backup_path.into())
 }

src/uu/factor/sieve.rs

@@ -30,7 +30,7 @@ impl Iterator for Sieve {
 
     #[inline]
     fn next(&mut self) -> Option<u64> {
-        while let Some(n) = self.inner.next() {
+        for n in &mut self.inner {
             let mut prime = true;
             while let Some((next, inc)) = self.filts.peek() {
                 // need to keep checking the min element of the heap

src/uu/head/src/parse.rs

@@ -14,7 +14,7 @@ pub fn parse_obsolete(src: &str) -> Option<Result<impl Iterator<Item = OsString>
         let mut num_end = 0usize;
         let mut has_num = false;
         let mut last_char = 0 as char;
-        while let Some((n, c)) = chars.next() {
+        for (n, c) in &mut chars {
             if c.is_numeric() {
                 has_num = true;
                 num_end = n;
@@ -109,7 +109,7 @@ pub fn parse_num(src: &str) -> Result<(usize, bool), ParseError> {
     let mut num_end = 0usize;
     let mut last_char = 0 as char;
     let mut num_count = 0usize;
-    while let Some((n, c)) = chars.next() {
+    for (n, c) in &mut chars {
         if c.is_numeric() {
             num_end = n;
             num_count += 1;

src/uu/install/src/install.rs

@@ -520,6 +520,7 @@ fn copy_file_to_file(file: &Path, target: &Path, b: &Behavior) -> i32 {
 ///
 /// If the copy system call fails, we print a verbose error and return an empty error value.
 ///
+#[allow(clippy::cognitive_complexity)]
 fn copy(from: &Path, to: &Path, b: &Behavior) -> Result<(), ()> {
     if b.compare && !need_copy(from, to, b) {
         return Ok(());

src/uu/ls/src/ls.rs

@@ -218,6 +218,7 @@ struct LongFormat {
 }
 
 impl Config {
+    #[allow(clippy::cognitive_complexity)]
     fn from(options: clap::ArgMatches) -> Config {
         let (mut format, opt) = if let Some(format_) = options.value_of(options::FORMAT) {
             (

src/uu/sort/src/chunks.rs

@@ -73,6 +73,7 @@ impl Chunk {
 /// * `lines`: The recycled vector to fill with lines. Must be empty.
 /// * `settings`: The global settings.
 #[allow(clippy::too_many_arguments)]
+#[allow(clippy::borrowed_box)]
 pub fn read(
     sender_option: &mut Option<SyncSender<Chunk>>,
     mut buffer: Vec<u8>,
@@ -164,6 +165,7 @@ fn parse_lines<'a>(
 ///   The remaining bytes must be copied to the start of the buffer for the next invocation,
 ///   if another invocation is necessary, which is determined by the other return value.
 /// * Whether this function should be called again.
+#[allow(clippy::borrowed_box)]
 fn read_to_buffer(
     file: &mut Box<dyn Read + Send>,
     next_files: &mut impl Iterator<Item = Box<dyn Read + Send>>,

src/uu/split/src/split.rs

@@ -200,6 +200,7 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
     split(&settings)
 }
 
+#[allow(dead_code)]
 struct Settings {
     prefix: String,
     numeric_suffix: bool,
@@ -210,7 +211,7 @@ struct Settings {
     filter: Option<String>,
     strategy: String,
     strategy_param: String,
-    verbose: bool,
+    verbose: bool, // TODO: warning: field is never read: `verbose`
 }
 
 trait Splitter {

src/uu/sync/src/sync.rs

@@ -199,6 +199,7 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
         }
     }
 
+    #[allow(clippy::if_same_then_else)]
     if matches.is_present(options::FILE_SYSTEM) {
         #[cfg(any(target_os = "linux", target_os = "windows"))]
         syncfs(files);

src/uu/test/src/parser.rs

@@ -265,11 +265,10 @@ impl Parser {
     fn boolop(&mut self, op: Symbol) {
         if op == Symbol::BoolOp(OsString::from("-a")) {
             self.term();
-            self.stack.push(op);
         } else {
             self.expr();
-            self.stack.push(op);
         }
+        self.stack.push(op);
     }
 
     /// Parse a (possible) unary argument test (string length or file

src/uu/touch/src/touch.rs

@@ -145,14 +145,9 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
         || matches.is_present(options::sources::CURRENT)
     {
         let timestamp = if matches.is_present(options::sources::DATE) {
-            parse_date(matches.value_of(options::sources::DATE).unwrap().as_ref())
+            parse_date(matches.value_of(options::sources::DATE).unwrap())
         } else {
-            parse_timestamp(
-                matches
-                    .value_of(options::sources::CURRENT)
-                    .unwrap()
-                    .as_ref(),
-            )
+            parse_timestamp(matches.value_of(options::sources::CURRENT).unwrap())
         };
         (timestamp, timestamp)
     } else {

src/uu/tr/src/expand.rs

@@ -110,7 +110,7 @@ impl<'a> Iterator for ExpandSet<'a> {
     fn next(&mut self) -> Option<Self::Item> {
         // while the Range has elements, try to return chars from it
         // but make sure that they actually turn out to be Chars!
-        while let Some(n) = self.range.next() {
+        for n in &mut self.range {
             if let Some(c) = from_u32(n) {
                 return Some(c);
             }

src/uu/who/src/who.rs

@@ -551,10 +551,11 @@ impl Who {
             "  ?".into()
         };
 
-        let mut s = ut.host();
-        if self.do_lookup {
-            s = safe_unwrap!(ut.canon_host());
-        }
+        let s = if self.do_lookup {
+            safe_unwrap!(ut.canon_host())
+        } else {
+            ut.host()
+        };
         let hoststr = if s.is_empty() { s } else { format!("({})", s) };
 
         self.print_line(

src/uucore/src/lib/features/fsext.rs

@@ -179,7 +179,7 @@ impl MountInfo {
             /* for Irix 6.5 */
             | "ignore" => self.dummy = true,
             _ => self.dummy = self.fs_type == "none"
-                && self.mount_option.find(MOUNT_OPT_BIND).is_none(),
+                && !self.mount_option.contains(MOUNT_OPT_BIND)
         }
         // set MountInfo::remote
         #[cfg(windows)]

src/uucore/src/lib/features/process.rs

@@ -40,6 +40,7 @@ pub enum ExitStatus {
     Signal(i32),
 }
 
+#[allow(clippy::trivially_copy_pass_by_ref)]
 impl ExitStatus {
     fn from_std_status(status: StdExitStatus) -> Self {
         #[cfg(unix)]

tests/by-util/test_base32.rs

@@ -34,7 +34,7 @@ fn test_base32_encode_file() {
 
 #[test]
 fn test_decode() {
-    for decode_param in vec!["-d", "--decode"] {
+    for decode_param in &["-d", "--decode"] {
         let input = "JBSWY3DPFQQFO33SNRSCC===\n";
         new_ucmd!()
             .arg(decode_param)
@@ -56,7 +56,7 @@ fn test_garbage() {
 
 #[test]
 fn test_ignore_garbage() {
-    for ignore_garbage_param in vec!["-i", "--ignore-garbage"] {
+    for ignore_garbage_param in &["-i", "--ignore-garbage"] {
         let input = "JBSWY\x013DPFQ\x02QFO33SNRSCC===\n";
         new_ucmd!()
             .arg("-d")
@@ -69,7 +69,7 @@ fn test_ignore_garbage() {
 
 #[test]
 fn test_wrap() {
-    for wrap_param in vec!["-w", "--wrap"] {
+    for wrap_param in &["-w", "--wrap"] {
         let input = "The quick brown fox jumps over the lazy dog.";
         new_ucmd!()
             .arg(wrap_param)
@@ -84,16 +84,21 @@ fn test_wrap() {
 
 #[test]
 fn test_wrap_no_arg() {
-    for wrap_param in vec!["-w", "--wrap"] {
-        new_ucmd!().arg(wrap_param).fails().stderr_only(format!(
-            "error: The argument '--wrap <wrap>\' requires a value but none was supplied\n\nUSAGE:\n    base32 [OPTION]... [FILE]\n\nFor more information try --help"
-        ));
+    for wrap_param in &["-w", "--wrap"] {
+        let expected_stderr = "error: The argument '--wrap <wrap>\' requires a value but none was \
+                               supplied\n\nUSAGE:\n    base32 [OPTION]... [FILE]\n\nFor more \
+                               information try --help"
+            .to_string();
+        new_ucmd!()
+            .arg(wrap_param)
+            .fails()
+            .stderr_only(expected_stderr);
     }
 }
 
 #[test]
 fn test_wrap_bad_arg() {
-    for wrap_param in vec!["-w", "--wrap"] {
+    for wrap_param in &["-w", "--wrap"] {
         new_ucmd!()
             .arg(wrap_param)
             .arg("b")

tests/by-util/test_base64.rs

@@ -26,7 +26,7 @@ fn test_base64_encode_file() {
 
 #[test]
 fn test_decode() {
-    for decode_param in vec!["-d", "--decode"] {
+    for decode_param in &["-d", "--decode"] {
         let input = "aGVsbG8sIHdvcmxkIQ==";
         new_ucmd!()
             .arg(decode_param)
@@ -48,7 +48,7 @@ fn test_garbage() {
 
 #[test]
 fn test_ignore_garbage() {
-    for ignore_garbage_param in vec!["-i", "--ignore-garbage"] {
+    for ignore_garbage_param in &["-i", "--ignore-garbage"] {
         let input = "aGVsbG8sIHdvcmxkIQ==\0";
         new_ucmd!()
             .arg("-d")
@@ -61,7 +61,7 @@ fn test_ignore_garbage() {
 
 #[test]
 fn test_wrap() {
-    for wrap_param in vec!["-w", "--wrap"] {
+    for wrap_param in &["-w", "--wrap"] {
         let input = "The quick brown fox jumps over the lazy dog.";
         new_ucmd!()
             .arg(wrap_param)
@@ -74,7 +74,7 @@ fn test_wrap() {
 
 #[test]
 fn test_wrap_no_arg() {
-    for wrap_param in vec!["-w", "--wrap"] {
+    for wrap_param in &["-w", "--wrap"] {
         new_ucmd!().arg(wrap_param).fails().stderr_contains(
             &"The argument '--wrap <wrap>' requires a value but none was supplied",
         );
@@ -83,7 +83,7 @@ fn test_wrap_no_arg() {
 
 #[test]
 fn test_wrap_bad_arg() {
-    for wrap_param in vec!["-w", "--wrap"] {
+    for wrap_param in &["-w", "--wrap"] {
         new_ucmd!()
             .arg(wrap_param)
             .arg("b")

tests/by-util/test_basename.rs

@@ -4,7 +4,7 @@ use std::ffi::OsStr;
 
 #[test]
 fn test_help() {
-    for help_flg in vec!["-h", "--help"] {
+    for help_flg in &["-h", "--help"] {
         new_ucmd!()
             .arg(&help_flg)
             .succeeds()
@@ -15,7 +15,7 @@ fn test_help() {
 
 #[test]
 fn test_version() {
-    for version_flg in vec!["-V", "--version"] {
+    for version_flg in &["-V", "--version"] {
         assert!(new_ucmd!()
             .arg(&version_flg)
             .succeeds()
@@ -59,7 +59,7 @@ fn test_dont_remove_suffix() {
 
 #[test]
 fn test_multiple_param() {
-    for multiple_param in vec!["-a", "--multiple"] {
+    for &multiple_param in &["-a", "--multiple"] {
         let path = "/foo/bar/baz";
         new_ucmd!()
             .args(&[multiple_param, path, path])
@@ -70,7 +70,7 @@ fn test_multiple_param() {
 
 #[test]
 fn test_suffix_param() {
-    for suffix_param in vec!["-s", "--suffix"] {
+    for &suffix_param in &["-s", "--suffix"] {
         let path = "/foo/bar/baz.exe";
         new_ucmd!()
             .args(&[suffix_param, ".exe", path, path])
@@ -81,7 +81,7 @@ fn test_suffix_param() {
 
 #[test]
 fn test_zero_param() {
-    for zero_param in vec!["-z", "--zero"] {
+    for &zero_param in &["-z", "--zero"] {
         let path = "/foo/bar/baz";
         new_ucmd!()
             .args(&[zero_param, "-a", path, path])
@@ -91,7 +91,12 @@ fn test_zero_param() {
 }
 
 fn expect_error(input: Vec<&str>) {
-    assert!(new_ucmd!().args(&input).fails().no_stdout().stderr().len() > 0);
+    assert!(!new_ucmd!()
+        .args(&input)
+        .fails()
+        .no_stdout()
+        .stderr_str()
+        .is_empty());
 }
 
 #[test]

tests/by-util/test_cat.rs

@@ -237,7 +237,7 @@ fn test_numbered_lines_no_trailing_newline() {
 
 #[test]
 fn test_stdin_show_nonprinting() {
-    for same_param in vec!["-v", "--show-nonprinting"] {
+    for same_param in &["-v", "--show-nonprinting"] {
         new_ucmd!()
             .args(&[same_param])
             .pipe_in("\t\0\n")
@@ -248,7 +248,7 @@ fn test_stdin_show_nonprinting() {
 
 #[test]
 fn test_stdin_show_tabs() {
-    for same_param in vec!["-T", "--show-tabs"] {
+    for same_param in &["-T", "--show-tabs"] {
         new_ucmd!()
             .args(&[same_param])
             .pipe_in("\t\0\n")
@@ -259,7 +259,7 @@ fn test_stdin_show_tabs() {
 
 #[test]
 fn test_stdin_show_ends() {
-    for same_param in vec!["-E", "--show-ends"] {
+    for &same_param in &["-E", "--show-ends"] {
         new_ucmd!()
             .args(&[same_param, "-"])
             .pipe_in("\t\0\n\t")
@@ -270,7 +270,7 @@ fn test_stdin_show_ends() {
 
 #[test]
 fn test_stdin_show_all() {
-    for same_param in vec!["-A", "--show-all"] {
+    for same_param in &["-A", "--show-all"] {
         new_ucmd!()
             .args(&[same_param])
             .pipe_in("\t\0\n")
@@ -299,7 +299,7 @@ fn test_stdin_nonprinting_and_tabs() {
 
 #[test]
 fn test_stdin_squeeze_blank() {
-    for same_param in vec!["-s", "--squeeze-blank"] {
+    for same_param in &["-s", "--squeeze-blank"] {
         new_ucmd!()
             .arg(same_param)
             .pipe_in("\n\na\n\n\n\n\nb\n\n\n")
@@ -310,7 +310,7 @@ fn test_stdin_squeeze_blank() {
 
 #[test]
 fn test_stdin_number_non_blank() {
-    for same_param in vec!["-b", "--number-nonblank"] {
+    for same_param in &["-b", "--number-nonblank"] {
         new_ucmd!()
             .arg(same_param)
             .arg("-")
@@ -322,7 +322,7 @@ fn test_stdin_number_non_blank() {
 
 #[test]
 fn test_non_blank_overrides_number() {
-    for same_param in vec!["-b", "--number-nonblank"] {
+    for &same_param in &["-b", "--number-nonblank"] {
         new_ucmd!()
             .args(&[same_param, "-"])
             .pipe_in("\na\nb\n\n\nc")
@@ -333,7 +333,7 @@ fn test_non_blank_overrides_number() {
 
 #[test]
 fn test_squeeze_blank_before_numbering() {
-    for same_param in vec!["-s", "--squeeze-blank"] {
+    for &same_param in &["-s", "--squeeze-blank"] {
         new_ucmd!()
             .args(&[same_param, "-n", "-"])
             .pipe_in("a\n\n\nb")
@@ -408,7 +408,10 @@ fn test_domain_socket() {
     use std::thread;
     use unix_socket::UnixListener;
 
-    let dir = tempfile::Builder::new().prefix("unix_socket").tempdir().expect("failed to create dir");
+    let dir = tempfile::Builder::new()
+        .prefix("unix_socket")
+        .tempdir()
+        .expect("failed to create dir");
     let socket_path = dir.path().join("sock");
     let listener = UnixListener::bind(&socket_path).expect("failed to create socket");
 
@@ -426,7 +429,7 @@ fn test_domain_socket() {
 
     let child = new_ucmd!().args(&[socket_path]).run_no_wait();
     barrier.wait();
-    let stdout = &child.wait_with_output().unwrap().stdout.clone();
+    let stdout = &child.wait_with_output().unwrap().stdout;
     let output = String::from_utf8_lossy(&stdout);
     assert_eq!("a\tb", output);
 

tests/by-util/test_chgrp.rs

@@ -6,7 +6,7 @@ fn test_invalid_option() {
     new_ucmd!().arg("-w").arg("/").fails();
 }
 
-static DIR: &'static str = "/tmp";
+static DIR: &str = "/tmp";
 
 #[test]
 fn test_invalid_group() {