fix clippy errors related to clap upgrade from 3.0.10 to 3.1.6

build.rs

@@ -43,7 +43,7 @@ pub fn main() {
     let mut tf = File::create(Path::new(&out_dir).join("test_modules.rs")).unwrap();
 
     mf.write_all(
-        "type UtilityMap<T> = phf::Map<&'static str, (fn(T) -> i32, fn() -> App<'static>)>;\n\
+        "type UtilityMap<T> = phf::Map<&'static str, (fn(T) -> i32, fn() -> Command<'static>)>;\n\
          \n\
          fn util_map<T: uucore::Args>() -> UtilityMap<T> {\n"
             .as_bytes(),

src/bin/coreutils.rs

@@ -5,7 +5,7 @@
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
 
-use clap::{App, Arg};
+use clap::{Arg, Command};
 use clap_complete::Shell;
 use std::cmp;
 use std::ffi::OsStr;
@@ -138,7 +138,7 @@ fn gen_completions<T: uucore::Args>(
         .chain(util_map.keys().copied())
         .collect();
 
-    let matches = App::new("completion")
+    let matches = Command::new("completion")
         .about("Prints completions to stdout")
         .arg(
             Arg::new("utility")
@@ -155,7 +155,7 @@ fn gen_completions<T: uucore::Args>(
     let utility = matches.value_of("utility").unwrap();
     let shell = matches.value_of("shell").unwrap();
 
-    let mut app = if utility == "coreutils" {
+    let mut command = if utility == "coreutils" {
         gen_coreutils_app(util_map)
     } else {
         util_map.get(utility).unwrap().1()
@@ -163,15 +163,15 @@ fn gen_completions<T: uucore::Args>(
     let shell: Shell = shell.parse().unwrap();
     let bin_name = std::env::var("PROG_PREFIX").unwrap_or_default() + utility;
 
-    clap_complete::generate(shell, &mut app, bin_name, &mut io::stdout());
+    clap_complete::generate(shell, &mut command, bin_name, &mut io::stdout());
     io::stdout().flush().unwrap();
     process::exit(0);
 }
 
-fn gen_coreutils_app<T: uucore::Args>(util_map: &UtilityMap<T>) -> App<'static> {
-    let mut app = App::new("coreutils");
+fn gen_coreutils_app<T: uucore::Args>(util_map: &UtilityMap<T>) -> Command<'static> {
+    let mut command = Command::new("coreutils");
     for (_, (_, sub_app)) in util_map {
-        app = app.subcommand(sub_app());
+        command = command.subcommand(sub_app());
     }
-    app
+    command
 }

src/bin/uudoc.rs

@@ -4,7 +4,7 @@
 // file that was distributed with this source code.
 // spell-checker:ignore tldr
 
-use clap::App;
+use clap::Command;
 use std::ffi::OsString;
 use std::fs::File;
 use std::io::Cursor;
@@ -46,13 +46,13 @@ fn main() -> io::Result<()> {
 
     let mut utils = utils.entries().collect::<Vec<_>>();
     utils.sort();
-    for (&name, (_, app)) in utils {
+    for (&name, (_, command)) in utils {
         if name == "[" {
             continue;
         }
         let p = format!("docs/src/utils/{}.md", name);
         if let Ok(f) = File::create(&p) {
-            write_markdown(f, &mut app(), name, &mut tldr_zip)?;
+            write_markdown(f, &mut command(), name, &mut tldr_zip)?;
             println!("Wrote to '{}'", p);
         } else {
             println!("Error writing to {}", p);
@@ -64,29 +64,29 @@ fn main() -> io::Result<()> {
 
 fn write_markdown(
     mut w: impl Write,
-    app: &mut App,
+    command: &mut Command,
     name: &str,
     tldr_zip: &mut zip::ZipArchive<impl Read + Seek>,
 ) -> io::Result<()> {
     write!(w, "# {}\n\n", name)?;
-    write_version(&mut w, app)?;
-    write_usage(&mut w, app, name)?;
-    write_description(&mut w, app)?;
-    write_options(&mut w, app)?;
+    write_version(&mut w, command)?;
+    write_usage(&mut w, command, name)?;
+    write_description(&mut w, command)?;
+    write_options(&mut w, command)?;
     write_examples(&mut w, name, tldr_zip)
 }
 
-fn write_version(w: &mut impl Write, app: &App) -> io::Result<()> {
+fn write_version(w: &mut impl Write, command: &Command) -> io::Result<()> {
     writeln!(
         w,
         "<div class=\"version\">version: {}</div>",
-        app.render_version().split_once(' ').unwrap().1
+        command.render_version().split_once(' ').unwrap().1
     )
 }
 
-fn write_usage(w: &mut impl Write, app: &mut App, name: &str) -> io::Result<()> {
+fn write_usage(w: &mut impl Write, command: &mut Command, name: &str) -> io::Result<()> {
     writeln!(w, "\n```")?;
-    let mut usage: String = app
+    let mut usage: String = command
         .render_usage()
         .lines()
         .skip(1)
@@ -99,8 +99,8 @@ fn write_usage(w: &mut impl Write, app: &mut App, name: &str) -> io::Result<()>
     writeln!(w, "```")
 }
 
-fn write_description(w: &mut impl Write, app: &App) -> io::Result<()> {
-    if let Some(about) = app.get_long_about().or_else(|| app.get_about()) {
+fn write_description(w: &mut impl Write, command: &Command) -> io::Result<()> {
+    if let Some(about) = command.get_long_about().or_else(|| command.get_about()) {
         writeln!(w, "{}", about)
     } else {
         Ok(())
@@ -152,10 +152,10 @@ fn get_zip_content(archive: &mut ZipArchive<impl Read + Seek>, name: &str) -> Op
     Some(s)
 }
 
-fn write_options(w: &mut impl Write, app: &App) -> io::Result<()> {
+fn write_options(w: &mut impl Write, command: &Command) -> io::Result<()> {
     writeln!(w, "<h2>Options</h2>")?;
     write!(w, "<dl>")?;
-    for arg in app.get_arguments() {
+    for arg in command.get_arguments() {
         write!(w, "<dt>")?;
         let mut first = true;
         for l in arg.get_long_and_visible_aliases().unwrap_or_default() {

src/uu/arch/src/arch.rs

@@ -8,7 +8,7 @@
 
 use platform_info::*;
 
-use clap::{crate_version, App, AppSettings};
+use clap::{crate_version, Command};
 use uucore::error::{FromIo, UResult};
 
 static ABOUT: &str = "Display machine architecture";
@@ -23,10 +23,10 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .after_help(SUMMARY)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
 }

src/uu/base32/src/base32.rs

@@ -7,7 +7,7 @@
 
 use std::io::{stdin, Read};
 
-use clap::App;
+use clap::Command;
 use uucore::{encoding::Format, error::UResult};
 
 pub mod base_common;
@@ -44,6 +44,6 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     )
 }
 
-pub fn uu_app<'a>() -> App<'a> {
+pub fn uu_app<'a>() -> Command<'a> {
     base_common::base_app(ABOUT, USAGE)
 }

src/uu/base32/src/base_common.rs

@@ -18,7 +18,7 @@ use std::fs::File;
 use std::io::{BufReader, Stdin};
 use std::path::Path;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 
 pub static BASE_CMD_PARSE_ERROR: i32 = 1;
 
@@ -86,19 +86,19 @@ impl Config {
 }
 
 pub fn parse_base_cmd_args(args: impl uucore::Args, about: &str, usage: &str) -> UResult<Config> {
-    let app = base_app(about, usage);
+    let command = base_app(about, usage);
     let arg_list = args
         .collect_str(InvalidEncodingHandling::ConvertLossy)
         .accept_any();
-    Config::from(&app.get_matches_from(arg_list))
+    Config::from(&command.get_matches_from(arg_list))
 }
 
-pub fn base_app<'a>(about: &'a str, usage: &'a str) -> App<'a> {
-    App::new(uucore::util_name())
+pub fn base_app<'a>(about: &'a str, usage: &'a str) -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(about)
         .override_usage(format_usage(usage))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         // Format arguments.
         .arg(
             Arg::new(options::DECODE)

src/uu/basename/src/basename.rs

@@ -7,7 +7,7 @@
 
 // spell-checker:ignore (ToDO) fullname
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::path::{is_separator, PathBuf};
 use uucore::display::Quotable;
 use uucore::error::{UResult, UUsageError};
@@ -87,12 +87,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(SUMMARY)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::MULTIPLE)
                 .short('a')

src/uu/basenc/src/basenc.rs

@@ -8,7 +8,7 @@
 
 //spell-checker:ignore (args) lsbf msbf
 
-use clap::{App, Arg};
+use clap::{Arg, Command};
 use uu_base32::base_common::{self, Config, BASE_CMD_PARSE_ERROR};
 
 use uucore::{
@@ -40,12 +40,12 @@ const ENCODINGS: &[(&str, Format)] = &[
 
 const USAGE: &str = "{} [OPTION]... [FILE]";
 
-pub fn uu_app<'a>() -> App<'a> {
-    let mut app = base_common::base_app(ABOUT, USAGE);
+pub fn uu_app<'a>() -> Command<'a> {
+    let mut command = base_common::base_app(ABOUT, USAGE);
     for encoding in ENCODINGS {
-        app = app.arg(Arg::new(encoding.0).long(encoding.0));
+        command = command.arg(Arg::new(encoding.0).long(encoding.0));
     }
-    app
+    command
 }
 
 fn parse_cmd_args(args: impl uucore::Args) -> UResult<(Config, Format)> {

src/uu/cat/src/cat.rs

@@ -14,7 +14,7 @@
 extern crate unix_socket;
 
 // last synced with: cat (GNU coreutils) 8.13
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::fs::{metadata, File};
 use std::io::{self, Read, Write};
 use thiserror::Error;
@@ -239,13 +239,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     cat_files(&files, &options)
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .name(NAME)
         .version(crate_version!())
         .override_usage(format_usage(USAGE))
         .about(SUMMARY)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::FILE)
                 .hide(true)

src/uu/chcon/src/chcon.rs

@@ -6,7 +6,7 @@ use uucore::error::{UResult, USimpleError, UUsageError};
 use uucore::format_usage;
 use uucore::{display::Quotable, show_error, show_warning};
 
-use clap::{App, AppSettings, Arg};
+use clap::{Arg, Command};
 use selinux::{OpaqueSecurityContext, SecurityContext};
 
 use std::borrow::Cow;
@@ -65,7 +65,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         Ok(r) => r,
         Err(r) => {
             if let Error::CommandLine(r) = &r {
-                match r.kind {
+                match r.kind() {
                     clap::ErrorKind::DisplayHelp | clap::ErrorKind::DisplayVersion => {
                         println!("{}", r);
                         return Ok(());
@@ -154,12 +154,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Err(libc::EXIT_FAILURE.into())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(VERSION)
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::dereference::DEREFERENCE)
                 .long(options::dereference::DEREFERENCE)
@@ -303,7 +303,7 @@ struct Options {
     files: Vec<PathBuf>,
 }
 
-fn parse_command_line(config: clap::App, args: impl uucore::Args) -> Result<Options> {
+fn parse_command_line(config: clap::Command, args: impl uucore::Args) -> Result<Options> {
     let matches = config.try_get_matches_from(args)?;
 
     let verbose = matches.is_present(options::VERBOSE);

src/uu/chgrp/src/chgrp.rs

@@ -13,7 +13,7 @@ use uucore::error::{FromIo, UResult, USimpleError};
 use uucore::format_usage;
 use uucore::perms::{chown_base, options, IfFrom};
 
-use clap::{App, AppSettings, Arg, ArgMatches};
+use clap::{Arg, ArgMatches, Command};
 
 use std::fs;
 use std::os::unix::fs::MetadataExt;
@@ -54,12 +54,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     chown_base(uu_app(), args, options::ARG_GROUP, parse_gid_and_uid, true)
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(VERSION)
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::verbosity::CHANGES)
                 .short('c')

src/uu/chmod/src/chmod.rs

@@ -7,7 +7,7 @@
 
 // spell-checker:ignore (ToDO) Chmoder cmode fmode fperm fref ugoa RFILE RFILE's
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::fs;
 use std::os::unix::fs::{MetadataExt, PermissionsExt};
 use std::path::Path;
@@ -112,12 +112,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     chmoder.chmod(&files)
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::CHANGES)
                 .long(options::CHANGES)

src/uu/chown/src/chown.rs

@@ -14,7 +14,7 @@ use uucore::perms::{chown_base, options, IfFrom};
 
 use uucore::error::{FromIo, UResult, USimpleError};
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 
 use std::fs;
 use std::os::unix::fs::MetadataExt;
@@ -63,12 +63,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     )
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::verbosity::CHANGES)
                 .short('c')

src/uu/chroot/src/chroot.rs

@@ -10,11 +10,11 @@
 mod error;
 
 use crate::error::ChrootError;
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::ffi::CString;
 use std::io::Error;
 use std::path::Path;
-use std::process::Command;
+use std::process;
 use uucore::error::{set_exit_code, UResult};
 use uucore::libc::{self, chroot, setgid, setgroups, setuid};
 use uucore::{entries, format_usage, InvalidEncodingHandling};
@@ -77,7 +77,10 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     // NOTE: Tests can only trigger code beyond this point if they're invoked with root permissions
     set_context(newroot, &matches)?;
 
-    let pstatus = match Command::new(chroot_command).args(chroot_args).status() {
+    let pstatus = match process::Command::new(chroot_command)
+        .args(chroot_args)
+        .status()
+    {
         Ok(status) => status,
         Err(e) => return Err(ChrootError::CommandFailed(command[0].to_string(), e).into()),
     };
@@ -91,12 +94,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::NEWROOT)
                 .hide(true)

src/uu/cksum/src/cksum.rs

@@ -6,7 +6,7 @@
 // file that was distributed with this source code.
 
 // spell-checker:ignore (ToDO) fname
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::fs::File;
 use std::io::{self, stdin, BufReader, Read};
 use std::path::Path;
@@ -140,13 +140,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .name(NAME)
         .version(crate_version!())
         .about(SUMMARY)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::FILE)
                 .hide(true)

src/uu/comm/src/comm.rs

@@ -15,7 +15,7 @@ use uucore::error::FromIo;
 use uucore::error::UResult;
 use uucore::{format_usage, InvalidEncodingHandling};
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 
 static ABOUT: &str = "compare two sorted files line by line";
 static LONG_HELP: &str = "";
@@ -143,13 +143,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .after_help(LONG_HELP)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::COLUMN_1)
                 .short('1')

src/uu/cp/src/cp.rs

@@ -28,7 +28,7 @@ use winapi::um::fileapi::GetFileInformationByHandle;
 
 use std::borrow::Cow;
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 use filetime::FileTime;
 #[cfg(unix)]
 use libc::mkfifo;
@@ -296,7 +296,7 @@ static DEFAULT_ATTRIBUTES: &[Attribute] = &[
     Attribute::Timestamps,
 ];
 
-pub fn uu_app<'a>() -> App<'a> {
+pub fn uu_app<'a>() -> Command<'a> {
     const MODE_ARGS: &[&str] = &[
         options::LINK,
         options::REFLINK,
@@ -304,11 +304,11 @@ pub fn uu_app<'a>() -> App<'a> {
         options::ATTRIBUTES_ONLY,
         options::COPY_CONTENTS,
     ];
-    App::new(uucore::util_name())
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(Arg::new(options::TARGET_DIRECTORY)
              .short('t')
              .conflicts_with(options::NO_TARGET_DIRECTORY)
@@ -389,7 +389,7 @@ pub fn uu_app<'a>() -> App<'a> {
              .long(options::PRESERVE)
              .takes_value(true)
              .multiple_occurrences(true)
-             .use_delimiter(true)
+             .use_value_delimiter(true)
              .possible_values(PRESERVABLE_ATTRIBUTES)
              .min_values(0)
              .value_name("ATTR_LIST")

src/uu/csplit/src/csplit.rs

@@ -12,7 +12,7 @@ use std::{
     io::{BufRead, BufWriter, Write},
 };
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 use regex::Regex;
 use uucore::display::Quotable;
 use uucore::error::{FromIo, UResult};
@@ -746,12 +746,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(SUMMARY)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::SUFFIX_FORMAT)
                 .short('b')

src/uu/cut/src/cut.rs

@@ -11,7 +11,7 @@
 extern crate uucore;
 
 use bstr::io::BufReadExt;
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::fs::File;
 use std::io::{stdin, stdout, BufReader, BufWriter, Read, Write};
 use std::path::Path;
@@ -533,14 +533,14 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .name(NAME)
         .version(crate_version!())
         .override_usage(format_usage(USAGE))
         .about(SUMMARY)
         .after_help(LONG_HELP)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::BYTES)
                 .short('b')

src/uu/date/src/date.rs

@@ -11,7 +11,7 @@
 use chrono::{DateTime, FixedOffset, Local, Offset, Utc};
 #[cfg(windows)]
 use chrono::{Datelike, Timelike};
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 #[cfg(all(unix, not(target_os = "macos"), not(target_os = "redox")))]
 use libc::{clock_settime, timespec, CLOCK_REALTIME};
 use std::fs::File;
@@ -254,12 +254,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(OPT_DATE)
                 .short('d')

src/uu/dd/src/dd.rs

@@ -34,7 +34,7 @@ use std::sync::mpsc;
 use std::thread;
 use std::time;
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 use gcd::Gcd;
 use uucore::display::Quotable;
 use uucore::error::{FromIo, UResult};
@@ -730,11 +730,11 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::INFILE)
                 .long(options::INFILE)
@@ -846,8 +846,8 @@ Printing performance stats is also triggered by the INFO signal (where supported
                 .long(options::CONV)
                 .takes_value(true)
                 .multiple_occurrences(true)
-                .use_delimiter(true)
-                .require_delimiter(true)
+                .use_value_delimiter(true)
+                .require_value_delimiter(true)
                 .multiple_values(true)
                 .require_equals(true)
                 .value_name("CONV")
@@ -887,8 +887,8 @@ Conversion Flags:
                 .long(options::IFLAG)
                 .takes_value(true)
                 .multiple_occurrences(true)
-                .use_delimiter(true)
-                .require_delimiter(true)
+                .use_value_delimiter(true)
+                .require_value_delimiter(true)
                 .multiple_values(true)
                 .require_equals(true)
                 .value_name("FLAG")
@@ -917,8 +917,8 @@ General-Flags
                 .long(options::OFLAG)
                 .takes_value(true)
                 .multiple_occurrences(true)
-                .use_delimiter(true)
-                .require_delimiter(true)
+                .use_value_delimiter(true)
+                .require_value_delimiter(true)
                 .multiple_values(true)
                 .require_equals(true)
                 .value_name("FLAG")

src/uu/df/src/df.rs

@@ -15,7 +15,7 @@ use uucore::error::{UResult, USimpleError};
 use uucore::format_usage;
 use uucore::fsext::{read_fs_list, MountInfo};
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 
 use std::fmt;
 use std::path::Path;
@@ -316,12 +316,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(OPT_ALL)
                 .short('a')
@@ -385,7 +385,7 @@ pub fn uu_app<'a>() -> App<'a> {
             Arg::new(OPT_OUTPUT)
                 .long("output")
                 .takes_value(true)
-                .use_delimiter(true)
+                .use_value_delimiter(true)
                 .possible_values(OUTPUT_FIELD_LIST)
                 .default_missing_values(&OUTPUT_FIELD_LIST)
                 .default_values(&["source", "size", "used", "avail", "pcent", "target"])
@@ -428,7 +428,7 @@ pub fn uu_app<'a>() -> App<'a> {
                 .long("exclude-type")
                 .allow_invalid_utf8(true)
                 .takes_value(true)
-                .use_delimiter(true)
+                .use_value_delimiter(true)
                 .multiple_occurrences(true)
                 .help("limit listing to file systems not of type TYPE"),
         )

src/uu/dircolors/src/dircolors.rs

@@ -13,7 +13,7 @@ use std::env;
 use std::fs::File;
 use std::io::{BufRead, BufReader};
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use uucore::display::Quotable;
 use uucore::error::{UResult, USimpleError, UUsageError};
 
@@ -154,13 +154,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(SUMMARY)
         .after_help(LONG_HELP)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::BOURNE_SHELL)
                 .long("sh")

src/uu/dirname/src/dirname.rs

@@ -5,7 +5,7 @@
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::path::Path;
 use uucore::display::print_verbatim;
 use uucore::error::{UResult, UUsageError};
@@ -76,12 +76,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .about(ABOUT)
         .version(crate_version!())
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::ZERO)
                 .long(options::ZERO)

src/uu/du/src/du.rs

@@ -10,7 +10,7 @@ extern crate uucore;
 
 use chrono::prelude::DateTime;
 use chrono::Local;
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 use std::collections::HashSet;
 use std::env;
 use std::fs;
@@ -617,13 +617,13 @@ fn parse_depth(max_depth_str: Option<&str>, summarize: bool) -> UResult<Option<u
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(SUMMARY)
         .after_help(LONG_HELP)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::ALL)
                 .short('a')

src/uu/echo/src/echo.rs

@@ -6,7 +6,7 @@
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::io::{self, Write};
 use std::iter::Peekable;
 use std::str::Chars;
@@ -126,15 +126,15 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         .map_err_context(|| "could not write to stdout".to_string())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .name(NAME)
         // TrailingVarArg specifies the final positional argument is a VarArg
         // and it doesn't attempts the parse any further args.
         // Final argument must have multiple(true) or the usage string equivalent.
-        .setting(AppSettings::TrailingVarArg)
-        .setting(AppSettings::AllowHyphenValues)
-        .setting(AppSettings::InferLongArgs)
+        .trailing_var_arg(true)
+        .allow_hyphen_values(true)
+        .infer_long_args(true)
         .version(crate_version!())
         .about(SUMMARY)
         .after_help(AFTER_HELP)

src/uu/env/src/env.rs

@@ -16,13 +16,13 @@ extern crate clap;
 #[macro_use]
 extern crate uucore;
 
-use clap::{App, AppSettings, Arg};
+use clap::{Arg, Command};
 use ini::Ini;
 use std::borrow::Cow;
 use std::env;
 use std::io::{self, Write};
 use std::iter::Iterator;
-use std::process::Command;
+use std::process;
 use uucore::display::Quotable;
 use uucore::error::{UResult, USimpleError, UUsageError};
 use uucore::format_usage;
@@ -121,15 +121,15 @@ fn build_command<'a, 'b>(args: &'a mut Vec<&'b str>) -> (Cow<'b, str>, &'a [&'b
     (progname, &args[..])
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(crate_name!())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(crate_name!())
         .version(crate_version!())
         .author(crate_authors!())
         .about(crate_description!())
         .override_usage(format_usage(USAGE))
         .after_help(AFTER_HELP)
-        .setting(AppSettings::AllowExternalSubcommands)
-        .setting(AppSettings::InferLongArgs)
+        .allow_external_subcommands(true)
+        .infer_long_args(true)
         .arg(Arg::new("ignore-environment")
             .short('i')
             .long("ignore-environment")
@@ -307,7 +307,7 @@ fn run_env(args: impl uucore::Args) -> UResult<()> {
          * standard library contains many checks and fail-safes to ensure the process ends up being
          * created. This is much simpler than dealing with the hassles of calling execvp directly.
          */
-        match Command::new(&*prog).args(args).status() {
+        match process::Command::new(&*prog).args(args).status() {
             Ok(exit) if !exit.success() => return Err(exit.code().unwrap().into()),
             Err(ref err) if err.kind() == io::ErrorKind::NotFound => return Err(127.into()),
             Err(_) => return Err(126.into()),

src/uu/expand/src/expand.rs

@@ -12,7 +12,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 use std::fs::File;
 use std::io::{stdin, stdout, BufRead, BufReader, BufWriter, Read, Write};
 use std::str::from_utf8;
@@ -176,13 +176,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     expand(&Options::new(&matches)).map_err_context(|| "failed to write output".to_string())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .after_help(LONG_HELP)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::INITIAL)
                 .long(options::INITIAL)

src/uu/expr/src/expr.rs

@@ -5,7 +5,7 @@
 //* For the full copyright and license information, please view the LICENSE
 //* file that was distributed with this source code.
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use uucore::error::{UResult, USimpleError};
 use uucore::InvalidEncodingHandling;
 
@@ -19,12 +19,12 @@ static USAGE: &str = r#"
     expr [EXPRESSION]
     expr [OPTIONS]"#;
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(USAGE)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(VERSION)
                 .long(VERSION)

src/uu/factor/src/cli.rs

@@ -14,7 +14,7 @@ use std::fmt::Write as FmtWrite;
 use std::io::{self, stdin, stdout, BufRead, Write};
 
 mod factor;
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 pub use factor::*;
 use uucore::display::Quotable;
 use uucore::error::UResult;
@@ -77,10 +77,10 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(SUMMARY)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(Arg::new(options::NUMBER).multiple_occurrences(true))
 }

src/uu/false/src/false.rs

@@ -4,7 +4,7 @@
 //  *
 //  * For the full copyright and license information, please view the LICENSE
 //  * file that was distributed with this source code.
-use clap::{App, AppSettings, Arg};
+use clap::{Arg, Command};
 use std::io::Write;
 use uucore::error::{set_exit_code, UResult};
 
@@ -18,7 +18,7 @@ the program will also return `1`.
 
 #[uucore::main]
 pub fn uumain(args: impl uucore::Args) -> UResult<()> {
-    let mut app = uu_app();
+    let mut command = uu_app();
 
     // Mirror GNU options, always return `1`. In particular even the 'successful' cases of no-op,
     // and the interrupted display of help and version should return `1`. Also, we return Ok in all
@@ -26,11 +26,11 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     // and unwind through the standard library allocation handling machinery.
     set_exit_code(1);
 
-    if let Ok(matches) = app.try_get_matches_from_mut(args) {
+    if let Ok(matches) = command.try_get_matches_from_mut(args) {
         let error = if matches.index_of("help").is_some() {
-            app.print_long_help()
+            command.print_long_help()
         } else if matches.index_of("version").is_some() {
-            writeln!(std::io::stdout(), "{}", app.render_version())
+            writeln!(std::io::stdout(), "{}", command.render_version())
         } else {
             Ok(())
         };
@@ -45,12 +45,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(clap::crate_version!())
         .about(ABOUT)
         // We provide our own help and version options, to ensure maximum compatibility with GNU.
-        .setting(AppSettings::DisableHelpFlag | AppSettings::DisableVersionFlag)
+        .disable_help_flag(true)
+        .disable_version_flag(true)
         .arg(
             Arg::new("help")
                 .long("help")

src/uu/fmt/src/fmt.rs

@@ -10,7 +10,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::cmp;
 use std::fs::File;
 use std::io::{stdin, stdout, Write};
@@ -218,12 +218,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(OPT_CROWN_MARGIN)
                 .short('c')

src/uu/fold/src/fold.rs

@@ -7,7 +7,7 @@
 
 // spell-checker:ignore (ToDOs) ncount routput
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::fs::File;
 use std::io::{stdin, BufRead, BufReader, Read};
 use std::path::Path;
@@ -63,13 +63,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     fold(&files, bytes, spaces, width)
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .name(NAME)
         .version(crate_version!())
         .override_usage(format_usage(USAGE))
         .about(SUMMARY)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::BYTES)
                 .long(options::BYTES)

src/uu/groups/src/groups.rs

@@ -26,7 +26,7 @@ use uucore::{
     format_usage,
 };
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 
 mod options {
     pub const USERS: &str = "USERNAME";
@@ -102,12 +102,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::USERS)
                 .multiple_occurrences(true)

src/uu/hashsum/src/hashsum.rs

@@ -20,7 +20,7 @@ mod digest;
 use self::digest::Digest;
 use self::digest::DigestWriter;
 
-use clap::{App, AppSettings, Arg, ArgMatches};
+use clap::{Arg, ArgMatches, Command};
 use hex::encode;
 use md5::Md5;
 use regex::Regex;
@@ -297,13 +297,13 @@ pub fn uumain(mut args: impl uucore::Args) -> UResult<()> {
     // Default binary in Windows, text mode otherwise
     let binary_flag_default = cfg!(windows);
 
-    let app = uu_app(&binary_name);
+    let command = uu_app(&binary_name);
 
     // FIXME: this should use try_get_matches_from() and crash!(), but at the moment that just
     //        causes "error: " to be printed twice (once from crash!() and once from clap).  With
     //        the current setup, the name of the utility is not printed, but I think this is at
     //        least somewhat better from a user's perspective.
-    let matches = app.get_matches_from(args);
+    let matches = command.get_matches_from(args);
 
     let (name, algo, bits) = detect_algo(&binary_name, &matches);
 
@@ -340,7 +340,7 @@ pub fn uumain(mut args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app_common<'a>() -> App<'a> {
+pub fn uu_app_common<'a>() -> Command<'a> {
     #[cfg(windows)]
     const BINARY_HELP: &str = "read in binary mode (default)";
     #[cfg(not(windows))]
@@ -349,10 +349,10 @@ pub fn uu_app_common<'a>() -> App<'a> {
     const TEXT_HELP: &str = "read in text mode";
     #[cfg(not(windows))]
     const TEXT_HELP: &str = "read in text mode (default)";
-    App::new(uucore::util_name())
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about("Compute and check message digests.")
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new("binary")
                 .short('b')
@@ -419,8 +419,8 @@ pub fn uu_app_common<'a>() -> App<'a> {
         )
 }
 
-pub fn uu_app_custom<'a>() -> App<'a> {
-    let mut app = uu_app_common();
+pub fn uu_app_custom<'a>() -> Command<'a> {
+    let mut command = uu_app_common();
     let algorithms = &[
         ("md5", "work with MD5"),
         ("sha1", "work with SHA1"),
@@ -446,14 +446,14 @@ pub fn uu_app_custom<'a>() -> App<'a> {
     ];
 
     for (name, desc) in algorithms {
-        app = app.arg(Arg::new(*name).long(name).help(*desc));
+        command = command.arg(Arg::new(*name).long(name).help(*desc));
     }
-    app
+    command
 }
 
 // hashsum is handled differently in build.rs, therefore this is not the same
 // as in other utilities.
-fn uu_app<'a>(binary_name: &str) -> App<'a> {
+fn uu_app<'a>(binary_name: &str) -> Command<'a> {
     if !is_custom_binary(binary_name) {
         uu_app_custom()
     } else {

src/uu/head/src/head.rs

@@ -5,7 +5,7 @@
 
 // spell-checker:ignore (vars) zlines BUFWRITER seekable
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 use std::convert::{TryFrom, TryInto};
 use std::ffi::OsString;
 use std::io::{self, BufWriter, ErrorKind, Read, Seek, SeekFrom, Write};
@@ -41,12 +41,12 @@ mod take;
 use take::take_all_but;
 use take::take_lines;
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::BYTES_NAME)
                 .short('c')

src/uu/hostid/src/hostid.rs

@@ -7,7 +7,7 @@
 
 // spell-checker:ignore (ToDO) gethostid
 
-use clap::{crate_version, App, AppSettings};
+use clap::{crate_version, Command};
 use libc::c_long;
 use uucore::{error::UResult, format_usage};
 
@@ -26,12 +26,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(SUMMARY)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
 }
 
 fn hostid() {

src/uu/hostname/src/hostname.rs

@@ -11,7 +11,7 @@ use std::collections::hash_set::HashSet;
 use std::net::ToSocketAddrs;
 use std::str;
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 
 use uucore::{
     error::{FromIo, UResult},
@@ -71,12 +71,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(OPT_DOMAIN)
                 .short('d')

src/uu/id/src/id.rs

@@ -39,7 +39,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::ffi::CStr;
 use uucore::display::Quotable;
 use uucore::entries::{self, Group, Locate, Passwd};
@@ -341,12 +341,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::OPT_AUDIT)
                 .short('A')

src/uu/install/src/install.rs

@@ -12,7 +12,7 @@ mod mode;
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 use file_diff::diff;
 use filetime::{set_file_times, FileTime};
 use uucore::backup_control::{self, BackupMode};
@@ -30,7 +30,7 @@ use std::fs;
 use std::fs::File;
 use std::os::unix::fs::MetadataExt;
 use std::path::{Path, PathBuf};
-use std::process::Command;
+use std::process;
 
 const DEFAULT_MODE: u32 = 0o755;
 const DEFAULT_STRIP_PROGRAM: &str = "strip";
@@ -188,12 +188,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             backup_control::arguments::backup()
         )
@@ -585,7 +585,7 @@ fn copy(from: &Path, to: &Path, b: &Behavior) -> UResult<()> {
     }
 
     if b.strip && cfg!(not(windows)) {
-        match Command::new(&b.strip_program).arg(to).output() {
+        match process::Command::new(&b.strip_program).arg(to).output() {
             Ok(o) => {
                 if !o.status.success() {
                     return Err(InstallError::StripProgramFailed(

src/uu/join/src/join.rs

@@ -10,7 +10,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use memchr::{memchr3_iter, memchr_iter};
 use std::cmp::Ordering;
 use std::convert::From;
@@ -697,8 +697,8 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(NAME)
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(NAME)
         .version(crate_version!())
         .about(
             "For each pair of input lines with identical join fields, write a line to
@@ -706,7 +706,7 @@ standard output. The default join field is the first, delimited by blanks.
 
 When FILE1 or FILE2 (not both) is -, read standard input.",
         )
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new("a")
                 .short('a')

src/uu/kill/src/kill.rs

@@ -10,7 +10,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use libc::{c_int, pid_t};
 use std::io::Error;
 use uucore::display::Quotable;
@@ -78,12 +78,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::LIST)
                 .short('l')

src/uu/link/src/link.rs

@@ -4,7 +4,7 @@
 //  *
 //  * For the full copyright and license information, please view the LICENSE
 //  * file that was distributed with this source code.
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::fs::hard_link;
 use std::path::Path;
 use uucore::display::Quotable;
@@ -33,12 +33,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         .map_err_context(|| format!("cannot create link {} to {}", new.quote(), old.quote()))
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::FILES)
                 .hide(true)

src/uu/ln/src/ln.rs

@@ -10,7 +10,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use uucore::display::Quotable;
 use uucore::error::{UError, UResult};
 use uucore::format_usage;
@@ -173,12 +173,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     exec(&paths[..], &settings)
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(backup_control::arguments::backup())
         .arg(backup_control::arguments::backup_no_args())
         // TODO: opts.arg(

src/uu/logname/src/logname.rs

@@ -12,7 +12,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings};
+use clap::{crate_version, Command};
 use std::ffi::CStr;
 use uucore::error::UResult;
 use uucore::InvalidEncodingHandling;
@@ -51,10 +51,10 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .override_usage(uucore::execution_phrase())
         .about(SUMMARY)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
 }

src/uu/ls/src/ls.rs

@@ -15,7 +15,7 @@ extern crate lazy_static;
 
 mod quoting_style;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use glob::Pattern;
 use lscolors::LsColors;
 use number_prefix::NumberPrefix;
@@ -782,9 +782,9 @@ impl Config {
 
 #[uucore::main]
 pub fn uumain(args: impl uucore::Args) -> UResult<()> {
-    let app = uu_app();
+    let command = uu_app();
 
-    let matches = app.get_matches_from(args);
+    let matches = command.get_matches_from(args);
 
     let config = Config::from(&matches)?;
 
@@ -796,8 +796,8 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     list(locs, &config)
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .override_usage(format_usage(USAGE))
         .about(
@@ -805,7 +805,7 @@ pub fn uu_app<'a>() -> App<'a> {
             the command line, expect that it will ignore files and directories \
             whose names start with '.'.",
         )
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         // Format arguments
         .arg(
             Arg::new(options::FORMAT)

src/uu/mkdir/src/mkdir.rs

@@ -10,7 +10,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches, OsValues};
+use clap::{crate_version, Arg, ArgMatches, Command, OsValues};
 use std::path::Path;
 use uucore::display::Quotable;
 #[cfg(not(windows))]
@@ -104,12 +104,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::MODE)
                 .short('m')

src/uu/mkfifo/src/mkfifo.rs

@@ -8,7 +8,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use libc::mkfifo;
 use std::ffi::CString;
 use uucore::error::{UResult, USimpleError};
@@ -70,13 +70,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .name(NAME)
         .version(crate_version!())
         .override_usage(format_usage(USAGE))
         .about(SUMMARY)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::MODE)
                 .short('m')

src/uu/mknod/src/mknod.rs

@@ -9,7 +9,7 @@
 
 use std::ffi::CString;
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 use libc::{dev_t, mode_t};
 use libc::{S_IFBLK, S_IFCHR, S_IFIFO, S_IRGRP, S_IROTH, S_IRUSR, S_IWGRP, S_IWOTH, S_IWUSR};
 
@@ -143,13 +143,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .override_usage(format_usage(USAGE))
         .after_help(LONG_HELP)
         .about(ABOUT)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new("mode")
                 .short('m')

src/uu/mktemp/src/mktemp.rs

@@ -8,7 +8,7 @@
 
 // spell-checker:ignore (paths) GPGHome
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use uucore::display::{println_verbatim, Quotable};
 use uucore::error::{FromIo, UError, UResult};
 use uucore::format_usage;
@@ -131,12 +131,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(OPT_DIRECTORY)
                 .short('d')

src/uu/more/src/more.rs

@@ -17,7 +17,7 @@ use std::{
 #[cfg(all(unix, not(target_os = "fuchsia")))]
 extern crate nix;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use crossterm::{
     event::{self, Event, KeyCode, KeyEvent, KeyModifiers},
     execute, queue,
@@ -96,11 +96,11 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .about("A file perusal filter for CRT viewing.")
         .version(crate_version!())
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::SILENT)
                 .short('d')

src/uu/mv/src/mv.rs

@@ -13,7 +13,7 @@ mod error;
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 use std::env;
 use std::ffi::OsString;
 use std::fs;
@@ -112,12 +112,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     exec(&files[..], &behavior)
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
     .arg(
         backup_control::arguments::backup()
     )

src/uu/nice/src/nice.rs

@@ -15,7 +15,7 @@ use std::ffi::CString;
 use std::io::Error;
 use std::ptr;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use uucore::{
     error::{set_exit_code, UResult, USimpleError, UUsageError},
     format_usage,
@@ -102,12 +102,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::TrailingVarArg)
-        .setting(AppSettings::InferLongArgs)
+        .trailing_var_arg(true)
+        .infer_long_args(true)
         .version(crate_version!())
         .arg(
             Arg::new(options::ADJUSTMENT)

src/uu/nl/src/nl.rs

@@ -8,7 +8,7 @@
 
 // spell-checker:ignore (ToDO) corasick memchr
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::fs::File;
 use std::io::{stdin, BufRead, BufReader, Read};
 use std::iter::repeat;
@@ -139,12 +139,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .name(NAME)
         .version(crate_version!())
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::FILE)
                 .hide(true)

src/uu/nohup/src/nohup.rs

@@ -10,7 +10,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use libc::{c_char, dup2, execvp, signal};
 use libc::{SIGHUP, SIG_IGN};
 use std::env;
@@ -116,8 +116,8 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .after_help(LONG_HELP)
@@ -128,8 +128,8 @@ pub fn uu_app<'a>() -> App<'a> {
                 .required(true)
                 .multiple_occurrences(true),
         )
-        .setting(AppSettings::TrailingVarArg)
-        .setting(AppSettings::InferLongArgs)
+        .trailing_var_arg(true)
+        .infer_long_args(true)
 }
 
 fn replace_fds() -> UResult<()> {

src/uu/nproc/src/nproc.rs

@@ -7,7 +7,7 @@
 
 // spell-checker:ignore (ToDO) NPROCESSORS nprocs numstr threadstr sysconf
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::env;
 use uucore::display::Quotable;
 use uucore::error::{UResult, USimpleError};
@@ -68,12 +68,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(OPT_ALL)
                 .long(OPT_ALL)

src/uu/numfmt/src/numfmt.rs

@@ -11,7 +11,7 @@ use crate::errors::*;
 use crate::format::format_and_print;
 use crate::options::*;
 use crate::units::{Result, Unit};
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 use std::io::{BufRead, Write};
 use uucore::display::Quotable;
 use uucore::error::UResult;
@@ -186,14 +186,14 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .after_help(LONG_HELP)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::AllowNegativeNumbers)
-        .setting(AppSettings::InferLongArgs)
+        .allow_negative_numbers(true)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::DELIMITER)
                 .short('d')

src/uu/od/src/od.rs

@@ -5,7 +5,7 @@
 //  * For the full copyright and license information, please view the LICENSE
 //  * file that was distributed with this source code.
 
-// spell-checker:ignore (clap) DontDelimitTrailingValues
+// spell-checker:ignore (clap) dont
 // spell-checker:ignore (ToDO) formatteriteminfo inputdecoder inputoffset mockstream nrofbytes partialreader odfunc multifile exitcode
 
 #[macro_use]
@@ -43,7 +43,7 @@ use crate::parse_nrofbytes::parse_number_of_bytes;
 use crate::partialreader::*;
 use crate::peekreader::*;
 use crate::prn_char::format_ascii_dump;
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, AppSettings, Arg, ArgMatches, Command};
 use uucore::display::Quotable;
 use uucore::error::{UResult, USimpleError};
 use uucore::format_usage;
@@ -289,18 +289,16 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     odfunc(&mut input_offset, &mut input_decoder, &output_info)
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
         .after_help(LONG_HELP)
-        .setting(
-            AppSettings::TrailingVarArg |
-            AppSettings::DontDelimitTrailingValues |
-            AppSettings::DeriveDisplayOrder |
-            AppSettings::InferLongArgs
-        )
+        .trailing_var_arg(true)
+        .dont_delimit_trailing_values(true)
+        .infer_long_args(true)
+        .setting(AppSettings::DeriveDisplayOrder)
         .arg(
             Arg::new(options::ADDRESS_RADIX)
                 .short('A')

src/uu/paste/src/paste.rs

@@ -7,7 +7,7 @@
 
 // spell-checker:ignore (ToDO) delim
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::fs::File;
 use std::io::{stdin, stdout, BufRead, BufReader, Read, Write};
 use std::path::Path;
@@ -47,11 +47,11 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     paste(files, serial, delimiters)
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::SERIAL)
                 .long(options::SERIAL)

src/uu/pathchk/src/pathchk.rs

@@ -8,7 +8,7 @@
 //  * that was distributed with this source code.
 
 // spell-checker:ignore (ToDO) lstat
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::fs;
 use std::io::{ErrorKind, Write};
 use uucore::display::Quotable;
@@ -84,12 +84,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::POSIX)
                 .short('p')

src/uu/pinky/src/pinky.rs

@@ -18,7 +18,7 @@ use std::io::BufReader;
 use std::fs::File;
 use std::os::unix::fs::MetadataExt;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::path::PathBuf;
 use uucore::{format_usage, InvalidEncodingHandling};
 
@@ -123,12 +123,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::LONG_FORMAT)
                 .short('l')

src/uu/pr/src/pr.rs

@@ -11,7 +11,7 @@ extern crate quick_error;
 
 use chrono::offset::Local;
 use chrono::DateTime;
-use clap::{App, AppSettings, Arg, ArgMatches};
+use clap::{AppSettings, Arg, ArgMatches, Command};
 use itertools::Itertools;
 use quick_error::ResultExt;
 use regex::Regex;
@@ -192,13 +192,13 @@ quick_error! {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(VERSION)
         .about(ABOUT)
         .after_help(AFTER_HELP)
-        .setting(AppSettings::InferLongArgs)
-        .setting(AppSettings::AllArgsOverrideSelf)
+        .infer_long_args(true)
+        .args_override_self(true)
         .setting(AppSettings::NoAutoHelp)
         .setting(AppSettings::NoAutoVersion)
         .arg(
@@ -383,8 +383,8 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
 
     let opt_args = recreate_arguments(&args);
 
-    let mut app = uu_app();
-    let matches = match app.try_get_matches_from_mut(opt_args) {
+    let mut command = uu_app();
+    let matches = match command.try_get_matches_from_mut(opt_args) {
         Ok(m) => m,
         Err(e) => {
             e.print()?;
@@ -394,12 +394,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     };
 
     if matches.is_present(options::VERSION) {
-        println!("{}", app.render_long_version());
+        println!("{}", command.render_long_version());
         return Ok(());
     }
 
     if matches.is_present(options::HELP) {
-        app.print_long_help()?;
+        command.print_long_help()?;
         return Ok(());
     }
 

src/uu/printenv/src/printenv.rs

@@ -7,7 +7,7 @@
 
 /* last synced with: printenv (GNU coreutils) 8.13 */
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::env;
 use uucore::{error::UResult, format_usage};
 
@@ -56,12 +56,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(OPT_NULL)
                 .short('0')

src/uu/printf/src/printf.rs

@@ -2,7 +2,7 @@
 // spell-checker:ignore (change!) each's
 // spell-checker:ignore (ToDO) LONGHELP FORMATSTRING templating parameterizing formatstr
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use uucore::error::{UResult, UUsageError};
 use uucore::InvalidEncodingHandling;
 use uucore::{format_usage, memo};
@@ -288,9 +288,9 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
-        .setting(AppSettings::AllowHyphenValues)
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
+        .allow_hyphen_values(true)
         .version(crate_version!())
         .about(ABOUT)
         .after_help(AFTER_HELP)

src/uu/ptx/src/ptx.rs

@@ -7,7 +7,7 @@
 
 // spell-checker:ignore (ToDOs) corasick memchr Roff trunc oset iset
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use regex::Regex;
 use std::cmp;
 use std::collections::{BTreeSet, HashMap, HashSet};
@@ -702,13 +702,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     write_traditional_output(&config, &file_map, &word_set, &output_file)
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .name(NAME)
         .about(ABOUT)
         .version(crate_version!())
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::FILE)
                 .hide(true)

src/uu/pwd/src/pwd.rs

@@ -5,7 +5,7 @@
 //  * For the full copyright and license information, please view the LICENSE
 //  * file that was distributed with this source code.
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::env;
 use std::io;
 use std::path::PathBuf;
@@ -148,12 +148,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(OPT_LOGICAL)
                 .short('L')

src/uu/readlink/src/readlink.rs

@@ -10,7 +10,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::fs;
 use std::io::{stdout, Write};
 use std::path::{Path, PathBuf};
@@ -95,12 +95,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_help(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(OPT_CANONICALIZE)
                 .short('f')

src/uu/realpath/src/realpath.rs

@@ -10,7 +10,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::{
     io::{stdout, Write},
     path::{Path, PathBuf},
@@ -70,12 +70,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(OPT_QUIET)
                 .short('q')

src/uu/relpath/src/relpath.rs

@@ -7,7 +7,7 @@
 
 // spell-checker:ignore (ToDO) subpath absto absfrom absbase
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::env;
 use std::path::{Path, PathBuf};
 use uucore::display::println_verbatim;
@@ -78,12 +78,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     println_verbatim(result).map_err_context(String::new)
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(Arg::new(options::DIR).short('d').takes_value(true).help(
             "If any of FROM and TO is not subpath of DIR, output absolute path instead of relative",
         ))

src/uu/rm/src/rm.rs

@@ -10,7 +10,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use remove_dir_all::remove_dir_all;
 use std::collections::VecDeque;
 use std::fs;
@@ -139,12 +139,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(OPT_FORCE)
             .short('f')

src/uu/rmdir/src/rmdir.rs

@@ -10,7 +10,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::fs::{read_dir, remove_dir};
 use std::io;
 use std::path::Path;
@@ -170,12 +170,12 @@ struct Opts {
     verbose: bool,
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(OPT_IGNORE_FAIL_NON_EMPTY)
                 .long(OPT_IGNORE_FAIL_NON_EMPTY)

src/uu/runcon/src/runcon.rs

@@ -2,7 +2,7 @@
 
 use uucore::error::{UResult, UUsageError};
 
-use clap::{App, AppSettings, Arg};
+use clap::{Arg, Command};
 use selinux::{OpaqueSecurityContext, SecurityClass, SecurityContext};
 use uucore::format_usage;
 
@@ -48,7 +48,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         Ok(r) => r,
         Err(r) => {
             if let Error::CommandLine(ref r) = r {
-                match r.kind {
+                match r.kind() {
                     clap::ErrorKind::DisplayHelp | clap::ErrorKind::DisplayVersion => {
                         println!("{}", r);
                         return Ok(());
@@ -103,13 +103,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(VERSION)
         .about(ABOUT)
         .after_help(DESCRIPTION)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::COMPUTE)
                 .short('c')
@@ -162,7 +162,7 @@ pub fn uu_app<'a>() -> App<'a> {
         //
         // This is not how POSIX does things, but this is how the GNU implementation
         // parses its command line.
-        .setting(clap::AppSettings::TrailingVarArg)
+        .trailing_var_arg(true)
 }
 
 #[derive(Debug)]
@@ -205,7 +205,7 @@ struct Options {
     arguments: Vec<OsString>,
 }
 
-fn parse_command_line(config: App, args: impl uucore::Args) -> Result<Options> {
+fn parse_command_line(config: Command, args: impl uucore::Args) -> Result<Options> {
     let matches = config.try_get_matches_from(args)?;
 
     let compute_transition_context = matches.is_present(options::COMPUTE);

src/uu/seq/src/seq.rs

@@ -7,7 +7,7 @@
 use std::io::{stdout, ErrorKind, Write};
 use std::process::exit;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use num_traits::Zero;
 
 use uucore::error::FromIo;
@@ -141,11 +141,11 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
-        .setting(AppSettings::TrailingVarArg)
-        .setting(AppSettings::AllowNegativeNumbers)
-        .setting(AppSettings::InferLongArgs)
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
+        .trailing_var_arg(true)
+        .allow_negative_numbers(true)
+        .infer_long_args(true)
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))

src/uu/shred/src/shred.rs

@@ -8,7 +8,7 @@
 
 // spell-checker:ignore (words) writeback wipesync
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use rand::prelude::SliceRandom;
 use rand::Rng;
 use std::cell::{Cell, RefCell};
@@ -314,13 +314,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .after_help(AFTER_HELP)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::FORCE)
                 .long(options::FORCE)

src/uu/shuf/src/shuf.rs

@@ -7,7 +7,7 @@
 
 // spell-checker:ignore (ToDO) cmdline evec seps rvec fdata
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use rand::prelude::SliceRandom;
 use rand::RngCore;
 use std::fs::File;
@@ -119,13 +119,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .name(NAME)
         .about(ABOUT)
         .version(crate_version!())
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::ECHO)
                 .short('e')
@@ -134,7 +134,7 @@ pub fn uu_app<'a>() -> App<'a> {
                 .value_name("ARG")
                 .help("treat each ARG as an input line")
                 .multiple_occurrences(true)
-                .use_delimiter(false)
+                .use_value_delimiter(false)
                 .min_values(0)
                 .conflicts_with(options::INPUT_RANGE),
         )

src/uu/sleep/src/sleep.rs

@@ -13,7 +13,7 @@ use uucore::{
     format_usage,
 };
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 
 static ABOUT: &str = "Pause for NUMBER seconds.";
 const USAGE: &str = "\
@@ -41,13 +41,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .after_help(LONG_HELP)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::NUMBER)
                 .help("pause for NUMBER seconds")

src/uu/sort/src/sort.rs

@@ -25,7 +25,7 @@ mod numeric_str_cmp;
 mod tmp_dir;
 
 use chunks::LineData;
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use custom_str_cmp::custom_str_cmp;
 use ext_sort::ext_sort;
 use fnv::FnvHasher;
@@ -1268,12 +1268,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     exec(&mut files, &settings, output, &mut tmp_dir)
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::modes::SORT)
                 .long(options::modes::SORT)

src/uu/split/src/split.rs

@@ -13,7 +13,7 @@ mod platform;
 
 use crate::filenames::FilenameIterator;
 use crate::filenames::SuffixType;
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 use std::convert::TryInto;
 use std::env;
 use std::fmt;
@@ -62,13 +62,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about("Create output files containing consecutive or interleaved sections of input")
         .after_help(AFTER_HELP)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         // strategy (mutually exclusive)
         .arg(
             Arg::new(OPT_BYTES)

src/uu/stat/src/stat.rs

@@ -16,7 +16,7 @@ use uucore::fsext::{
 use uucore::libc::mode_t;
 use uucore::{entries, format_usage};
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 use std::borrow::Cow;
 use std::convert::AsRef;
 use std::os::unix::fs::{FileTypeExt, MetadataExt};
@@ -967,12 +967,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::DEREFERENCE)
                 .short('L')

src/uu/stdbuf/src/stdbuf.rs

@@ -10,13 +10,13 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 use std::convert::{TryFrom, TryInto};
 use std::fs::File;
 use std::io::{self, Write};
 use std::os::unix::process::ExitStatusExt;
 use std::path::PathBuf;
-use std::process::Command;
+use std::process;
 use tempfile::tempdir;
 use tempfile::TempDir;
 use uucore::error::{FromIo, UResult, USimpleError, UUsageError};
@@ -131,7 +131,7 @@ fn check_option(matches: &ArgMatches, name: &str) -> Result<BufferType, ProgramO
     }
 }
 
-fn set_command_env(command: &mut Command, buffer_name: &str, buffer_type: &BufferType) {
+fn set_command_env(command: &mut process::Command, buffer_name: &str, buffer_type: &BufferType) {
     match buffer_type {
         BufferType::Size(m) => {
             command.env(buffer_name, m.to_string());
@@ -164,7 +164,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     let options = ProgramOptions::try_from(&matches).map_err(|e| UUsageError::new(125, e.0))?;
 
     let mut command_values = matches.values_of::<&str>(options::COMMAND).unwrap();
-    let mut command = Command::new(command_values.next().unwrap());
+    let mut command = process::Command::new(command_values.next().unwrap());
     let command_params: Vec<&str> = command_values.collect();
 
     let mut tmp_dir = tempdir().unwrap();
@@ -194,14 +194,14 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .after_help(LONG_HELP)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::TrailingVarArg)
-        .setting(AppSettings::InferLongArgs)
+        .trailing_var_arg(true)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::INPUT)
                 .long(options::INPUT)

src/uu/sum/src/sum.rs

@@ -10,7 +10,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::fs::File;
 use std::io::{stdin, Read};
 use std::path::Path;
@@ -140,13 +140,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .name(NAME)
         .version(crate_version!())
         .override_usage(format_usage(USAGE))
         .about(SUMMARY)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::FILE)
                 .multiple_occurrences(true)

src/uu/sync/src/sync.rs

@@ -9,7 +9,7 @@
 
 extern crate libc;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::path::Path;
 use uucore::display::Quotable;
 use uucore::error::{UResult, USimpleError};
@@ -190,12 +190,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::FILE_SYSTEM)
                 .short('f')

src/uu/tac/src/tac.rs

@@ -8,7 +8,7 @@
 // spell-checker:ignore (ToDO) sbytes slen dlen memmem memmap Mmap mmap SIGBUS
 mod error;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use memchr::memmem;
 use memmap2::Mmap;
 use std::io::{stdin, stdout, BufWriter, Read, Write};
@@ -60,13 +60,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     tac(&files, before, regex, separator)
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .name(NAME)
         .version(crate_version!())
         .override_usage(format_usage(USAGE))
         .about(SUMMARY)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::BEFORE)
                 .short('b')

src/uu/tail/src/tail.rs

@@ -20,7 +20,7 @@ mod parse;
 mod platform;
 use chunks::ReverseChunks;
 
-use clap::{App, AppSettings, Arg};
+use clap::{Arg, Command};
 use std::collections::VecDeque;
 use std::convert::TryInto;
 use std::ffi::OsString;
@@ -275,12 +275,12 @@ fn arg_iterate<'a>(
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::BYTES)
                 .short('c')

src/uu/tee/src/tee.rs

@@ -8,7 +8,7 @@
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use retain_mut::RetainMut;
 use std::fs::OpenOptions;
 use std::io::{copy, sink, stdin, stdout, Error, ErrorKind, Read, Result, Write};
@@ -55,13 +55,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
         .after_help("If a FILE is -, it refers to a file named - .")
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::APPEND)
                 .long(options::APPEND)

src/uu/test/src/test.rs

@@ -10,7 +10,7 @@
 
 mod parser;
 
-use clap::{crate_version, App};
+use clap::{crate_version, Command};
 use parser::{parse, Operator, Symbol, UnaryOperator};
 use std::ffi::{OsStr, OsString};
 use uucore::display::Quotable;
@@ -90,8 +90,8 @@ for details about the options it supports.";
 
 const ABOUT: &str = "Check file types and compare values.";
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
@@ -108,7 +108,7 @@ pub fn uumain(mut args: impl uucore::Args) -> UResult<()> {
         // If invoked as [ we should recognize --help and --version (but not -h or -v)
         if args.len() == 1 && (args[0] == "--help" || args[0] == "--version") {
             // Let clap pretty-print help and version
-            App::new(binary_name)
+            Command::new(binary_name)
                 .version(crate_version!())
                 .about(ABOUT)
                 .override_usage(format_usage(USAGE))

src/uu/timeout/src/timeout.rs

@@ -14,9 +14,9 @@ extern crate uucore;
 extern crate clap;
 
 use crate::status::ExitStatus;
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::io::ErrorKind;
-use std::process::{Child, Command, Stdio};
+use std::process::{self, Child, Stdio};
 use std::time::Duration;
 use uucore::display::Quotable;
 use uucore::error::{UResult, USimpleError};
@@ -103,9 +103,9 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         .collect_str(InvalidEncodingHandling::ConvertLossy)
         .accept_any();
 
-    let app = uu_app();
+    let command = uu_app();
 
-    let matches = app.get_matches_from(args);
+    let matches = command.get_matches_from(args);
 
     let config = Config::from(&matches)?;
     timeout(
@@ -119,8 +119,8 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     )
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new("timeout")
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new("timeout")
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
@@ -162,8 +162,8 @@ pub fn uu_app<'a>() -> App<'a> {
                 .required(true)
                 .multiple_occurrences(true)
         )
-        .setting(AppSettings::TrailingVarArg)
-        .setting(AppSettings::InferLongArgs)
+        .trailing_var_arg(true)
+        .infer_long_args(true)
 }
 
 /// Remove pre-existing SIGCHLD handlers that would make waiting for the child's exit code fail.
@@ -245,7 +245,7 @@ fn timeout(
     if !foreground {
         unsafe { libc::setpgid(0, 0) };
     }
-    let mut process = Command::new(&cmd[0])
+    let mut process = process::Command::new(&cmd[0])
         .args(&cmd[1..])
         .stdin(Stdio::inherit())
         .stdout(Stdio::inherit())

src/uu/touch/src/touch.rs

@@ -13,7 +13,7 @@ pub extern crate filetime;
 #[macro_use]
 extern crate uucore;
 
-use clap::{crate_version, App, AppSettings, Arg, ArgGroup};
+use clap::{crate_version, Arg, ArgGroup, Command};
 use filetime::*;
 use std::fs::{self, File};
 use std::path::{Path, PathBuf};
@@ -149,12 +149,12 @@ Try 'touch --help' for more information."##,
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::ACCESS)
                 .short('a')

src/uu/tr/src/tr.rs

@@ -11,7 +11,7 @@ mod convert;
 mod operation;
 mod unicode_table;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use nom::AsBytes;
 use operation::{translate_input, Sequence, SqueezeOperation, TranslateOperation};
 use std::io::{stdin, stdout, BufReader, BufWriter};
@@ -137,13 +137,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::COMPLEMENT)
                 .visible_short_alias('C')

src/uu/true/src/true.rs

@@ -4,7 +4,7 @@
 //  *
 //  * For the full copyright and license information, please view the LICENSE
 //  * file that was distributed with this source code.
-use clap::{App, AppSettings, Arg};
+use clap::{Arg, Command};
 use std::io::Write;
 use uucore::error::{set_exit_code, UResult};
 
@@ -18,13 +18,13 @@ operation causes the program to return `1` instead.
 
 #[uucore::main]
 pub fn uumain(args: impl uucore::Args) -> UResult<()> {
-    let mut app = uu_app();
+    let mut command = uu_app();
 
-    if let Ok(matches) = app.try_get_matches_from_mut(args) {
+    if let Ok(matches) = command.try_get_matches_from_mut(args) {
         let error = if matches.index_of("help").is_some() {
-            app.print_long_help()
+            command.print_long_help()
         } else if matches.index_of("version").is_some() {
-            writeln!(std::io::stdout(), "{}", app.render_version())
+            writeln!(std::io::stdout(), "{}", command.render_version())
         } else {
             Ok(())
         };
@@ -42,12 +42,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(clap::crate_version!())
         .about(ABOUT)
         // We provide our own help and version options, to ensure maximum compatibility with GNU.
-        .setting(AppSettings::DisableHelpFlag | AppSettings::DisableVersionFlag)
+        .disable_help_flag(true)
+        .disable_version_flag(true)
         .arg(
             Arg::new("help")
                 .long("help")

src/uu/truncate/src/truncate.rs

@@ -6,7 +6,7 @@
 //  * file that was distributed with this source code.
 
 // spell-checker:ignore (ToDO) RFILE refsize rfilename fsize tsize
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::fs::{metadata, OpenOptions};
 use std::io::ErrorKind;
 #[cfg(unix)]
@@ -115,7 +115,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         .try_get_matches_from(args)
         .map_err(|e| {
             e.print().expect("Error writing clap::Error");
-            match e.kind {
+            match e.kind() {
                 clap::ErrorKind::DisplayHelp | clap::ErrorKind::DisplayVersion => 0,
                 _ => 1,
             }
@@ -137,12 +137,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::IO_BLOCKS)
             .short('o')

src/uu/tsort/src/tsort.rs

@@ -5,7 +5,7 @@
 //  *
 //  * For the full copyright and license information, please view the LICENSE
 //  * file that was distributed with this source code.
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::collections::{HashMap, HashSet};
 use std::fs::File;
 use std::io::{stdin, BufRead, BufReader, Read};
@@ -93,12 +93,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .override_usage(format_usage(USAGE))
         .about(SUMMARY)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(Arg::new(options::FILE).default_value("-").hide(true))
 }
 

src/uu/tty/src/tty.rs

@@ -9,7 +9,7 @@
 
 // spell-checker:ignore (ToDO) ttyname filedesc
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::ffi::CStr;
 use std::io::Write;
 use uucore::error::{UResult, UUsageError};
@@ -66,12 +66,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::SILENT)
                 .long(options::SILENT)

src/uu/uname/src/uname.rs

@@ -10,7 +10,7 @@
 
 // spell-checker:ignore (ToDO) nodename kernelname kernelrelease kernelversion sysname hwplatform mnrsv
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use platform_info::*;
 use uucore::{
     error::{FromIo, UResult},
@@ -121,12 +121,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(Arg::new(options::ALL)
             .short('a')
             .long(options::ALL)

src/uu/unexpand/src/unexpand.rs

@@ -11,7 +11,7 @@
 
 #[macro_use]
 extern crate uucore;
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use std::fs::File;
 use std::io::{stdin, stdout, BufRead, BufReader, BufWriter, Read, Stdout, Write};
 use std::str::from_utf8;
@@ -102,13 +102,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     unexpand(&Options::new(&matches)).map_err_context(String::new)
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .name(NAME)
         .version(crate_version!())
         .override_usage(format_usage(USAGE))
         .about(SUMMARY)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(Arg::new(options::FILE).hide(true).multiple_occurrences(true))
         .arg(
             Arg::new(options::ALL)

src/uu/uniq/src/uniq.rs

@@ -5,7 +5,7 @@
 //  * For the full copyright and license information, please view the LICENSE
 //  * file that was distributed with this source code.
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 use std::fs::File;
 use std::io::{self, stdin, stdout, BufRead, BufReader, BufWriter, Read, Write};
 use std::path::Path;
@@ -290,12 +290,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     )
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::ALL_REPEATED)
                 .short('D')

src/uu/unlink/src/unlink.rs

@@ -10,7 +10,7 @@
 use std::fs::remove_file;
 use std::path::Path;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 
 use uucore::display::Quotable;
 use uucore::error::{FromIo, UResult};
@@ -27,11 +27,11 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     remove_file(path).map_err_context(|| format!("cannot unlink {}", path.quote()))
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(OPT_PATH)
                 .required(true)

src/uu/uptime/src/uptime.rs

@@ -9,7 +9,7 @@
 // spell-checker:ignore (ToDO) getloadavg upsecs updays nusers loadavg boottime uphours upmins
 
 use chrono::{Local, TimeZone, Utc};
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 
 use uucore::format_usage;
 // import crate time from utmpx
@@ -59,12 +59,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     }
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::SINCE)
                 .short('s')

src/uu/users/src/users.rs

@@ -10,7 +10,7 @@
 
 use std::path::Path;
 
-use clap::{crate_version, App, AppSettings, Arg};
+use clap::{crate_version, Arg, Command};
 use uucore::error::UResult;
 use uucore::format_usage;
 use uucore::utmpx::{self, Utmpx};
@@ -58,11 +58,11 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(Arg::new(ARG_FILES).takes_value(true).max_values(1))
 }

src/uu/wc/src/wc.rs

@@ -18,7 +18,7 @@ use utf8::{BufReadDecoder, BufReadDecoderError};
 use uucore::format_usage;
 use word_count::{TitledWordCount, WordCount};
 
-use clap::{crate_version, App, AppSettings, Arg, ArgMatches};
+use clap::{crate_version, Arg, ArgMatches, Command};
 
 use std::cmp::max;
 use std::error::Error;
@@ -183,12 +183,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     wc(&inputs, &settings)
 }
 
-pub fn uu_app<'a>() -> App<'a> {
-    App::new(uucore::util_name())
+pub fn uu_app<'a>() -> Command<'a> {
+    Command::new(uucore::util_name())
         .version(crate_version!())
         .about(ABOUT)
         .override_usage(format_usage(USAGE))
-        .setting(AppSettings::InferLongArgs)
+        .infer_long_args(true)
         .arg(
             Arg::new(options::BYTES)
                 .short('c')