cp: Use PathBuf instead of String for paths

I think this should avoid unnecessarily validating utf-8, and avoids a few allocations.

src/uu/cp/src/cp.rs

@@ -26,7 +26,7 @@ use std::os::unix::fs::{FileTypeExt, PermissionsExt};
 use std::path::{Path, PathBuf, StripPrefixError};
 use std::string::ToString;
 
-use clap::{crate_version, Arg, ArgAction, ArgMatches, Command};
+use clap::{builder::ValueParser, crate_version, Arg, ArgAction, ArgMatches, Command};
 use filetime::FileTime;
 use indicatif::{ProgressBar, ProgressStyle};
 #[cfg(unix)]
@@ -91,7 +91,7 @@ quick_error! {
  /// Invalid arguments to backup
  Backup(description: String) { display("{}\nTry '{} --help' for more information.", description, uucore::execution_phrase()) }
 
- NotADirectory(path: String) { display("'{}' is not a directory", path) }
+ NotADirectory(path: PathBuf) { display("'{}' is not a directory", path.display()) }
  }
 }
 
@@ -222,7 +222,7 @@ pub struct Options {
  attributes: Attributes,
  recursive: bool,
  backup_suffix: String,
- target_dir: Option<String>,
+ target_dir: Option<PathBuf>,
  update: bool,
  verbose: bool,
  progress_bar: bool,
@@ -305,6 +305,7 @@ pub fn uu_app() -> Command {
  .long(options::TARGET_DIRECTORY)
  .value_name(options::TARGET_DIRECTORY)
  .value_hint(clap::ValueHint::DirPath)
+ .value_parser(ValueParser::path_buf())
  .help("copy all SOURCE arguments into target-directory"),
  )
  .arg(
@@ -558,7 +559,8 @@ pub fn uu_app() -> Command {
  .arg(
  Arg::new(options::PATHS)
  .action(ArgAction::Append)
- .value_hint(clap::ValueHint::AnyPath),
+ .value_hint(clap::ValueHint::AnyPath)
+ .value_parser(ValueParser::path_buf()),
  )
 }
 
@@ -579,7 +581,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
  clap::error::ErrorKind::DisplayVersion => print!("{}", app.render_version()),
  _ => return Err(Box::new(e.with_exit_code(1))),
  };
- } else if let Ok(matches) = matches {
+ } else if let Ok(mut matches) = matches {
  let options = Options::from_matches(&matches)?;
 
  if options.overwrite == OverwriteMode::NoClobber && options.backup != BackupMode::NoBackup {
@@ -589,12 +591,12 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
  ));
  }
 
- let paths: Vec<String> = matches
- .get_many::<String>(options::PATHS)
- .map(|v| v.map(ToString::to_string).collect())
+ let paths: Vec<PathBuf> = matches
+ .remove_many::<PathBuf>(options::PATHS)
+ .map(|v| v.collect())
  .unwrap_or_default();
 
- let (sources, target) = parse_path_args(&paths, &options)?;
+ let (sources, target) = parse_path_args(paths, &options)?;
 
  if let Err(error) = copy(&sources, &target, &options) {
  match error {
@@ -757,11 +759,11 @@ impl Options {
  // Parse target directory options
  let no_target_dir = matches.get_flag(options::NO_TARGET_DIRECTORY);
  let target_dir = matches
- .get_one::<String>(options::TARGET_DIRECTORY)
- .map(ToString::to_string);
+ .get_one::<PathBuf>(options::TARGET_DIRECTORY)
+ .cloned();
 
  if let Some(dir) = &target_dir {
- if !Path::new(dir).is_dir() {
+ if !dir.is_dir() {
  return Err(Error::NotADirectory(dir.clone()));
  }
  };
@@ -918,9 +920,7 @@ impl TargetType {
 }
 
 /// Returns tuple of (Source paths, Target)
-fn parse_path_args(path_args: &[String], options: &Options) -> CopyResult<(Vec<Source>, Target)> {
- let mut paths = path_args.iter().map(PathBuf::from).collect::<Vec<_>>();
-
+fn parse_path_args(mut paths: Vec<Source>, options: &Options) -> CopyResult<(Vec<Source>, Target)> {
  if paths.is_empty() {
  // No files specified
  return Err("missing file operand".into());
@@ -936,7 +936,7 @@ fn parse_path_args(path_args: &[String], options: &Options) -> CopyResult<(Vec<S
  Some(ref target) => {
  // All path args are sources, and the target dir was
  // specified separately
- PathBuf::from(target)
+ target.clone()
  }
  None => {
  // If there was no explicit target-dir, then use the last