du: implement files0-from

Should make tests/du/files0-from-dir pass

src/uu/du/src/du.rs

@@ -65,6 +65,7 @@ mod options {
     pub const INODES: &str = "inodes";
     pub const EXCLUDE: &str = "exclude";
     pub const EXCLUDE_FROM: &str = "exclude-from";
+    pub const FILES0_FROM: &str = "files0-from";
     pub const VERBOSE: &str = "verbose";
     pub const FILE: &str = "FILE";
 }
@@ -587,6 +588,37 @@ pub fn div_ceil(a: u64, b: u64) -> u64 {
     (a + b - 1) / b
 }
 
+fn read_files_from(file_name: &str) -> Result<Vec<PathBuf>, std::io::Error> {
+    let reader: Box<dyn BufRead> = if file_name == "-" {
+        // Read from standard input
+        Box::new(BufReader::new(std::io::stdin()))
+    } else {
+        // First, check if the file_name is a directory
+        let path = PathBuf::from(file_name);
+        if path.is_dir() {
+            // Return an error if it's a directory
+            return Err(std::io::Error::new(
+                std::io::ErrorKind::Other,
+                format!("{}: read error: Is a directory", file_name),
+            ));
+        }
+
+        // Read from a file
+        Box::new(BufReader::new(File::open(file_name)?))
+    };
+
+    let mut paths = Vec::new();
+
+    for line in reader.split(b'\0') {
+        let path = line?;
+        if !path.is_empty() {
+            paths.push(PathBuf::from(String::from_utf8_lossy(&path).to_string()));
+        }
+    }
+
+    Ok(paths)
+}
+
 #[uucore::main]
 #[allow(clippy::cognitive_complexity)]
 pub fn uumain(args: impl uucore::Args) -> UResult<()> {
@@ -601,13 +633,18 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         summarize,
     )?;
 
-    let files = match matches.get_one::<String>(options::FILE) {
-        Some(_) => matches
-            .get_many::<String>(options::FILE)
-            .unwrap()
-            .map(PathBuf::from)
-            .collect(),
-        None => vec![PathBuf::from(".")],
+    let files = if let Some(file_from) = matches.get_one::<String>(options::FILES0_FROM) {
+        // Read file paths from the specified file, separated by null characters
+        read_files_from(file_from)?
+    } else {
+        match matches.get_one::<String>(options::FILE) {
+            Some(_) => matches
+                .get_many::<String>(options::FILE)
+                .unwrap()
+                .map(PathBuf::from)
+                .collect(),
+            None => vec![PathBuf::from(".")],
+        }
     };
 
     let time = matches.contains_id(options::TIME).then(|| {
@@ -954,6 +991,14 @@ pub fn uu_app() -> Command {
                 .help("exclude files that match any pattern in FILE")
                 .action(ArgAction::Append)
         )
+        .arg(
+            Arg::new(options::FILES0_FROM)
+                .long("files0-from")
+                .value_name("FILE")
+                .value_hint(clap::ValueHint::FilePath)
+                .help("summarize device usage of the NUL-terminated file names specified in file F; if F is -, then read names from standard input")
+                .action(ArgAction::Append)
+        )
         .arg(
             Arg::new(options::TIME)
                 .long(options::TIME)

tests/by-util/test_du.rs

@@ -3,7 +3,7 @@
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
 
-// spell-checker:ignore (paths) sublink subwords azerty azeaze xcwww azeaz amaz azea qzerty tazerty tsublink
+// spell-checker:ignore (paths) sublink subwords azerty azeaze xcwww azeaz amaz azea qzerty tazerty tsublink testfile1 testfile2 filelist testdir
 #[cfg(not(windows))]
 use regex::Regex;
 #[cfg(not(windows))]
@@ -935,3 +935,61 @@ fn test_du_symlink_multiple_fail() {
     assert_eq!(result.code(), 1);
     result.stdout_contains("4\tfile1\n");
 }
+
+#[test]
+// Disable on Windows because of different path separators and handling of null characters
+#[cfg(not(target_os = "windows"))]
+fn test_du_files0_from() {
+    let ts = TestScenario::new(util_name!());
+    let at = &ts.fixtures;
+
+    let mut file1 = at.make_file("testfile1");
+    file1.write_all(b"content1").unwrap();
+    let mut file2 = at.make_file("testfile2");
+    file2.write_all(b"content2").unwrap();
+
+    at.mkdir_all("testdir");
+    let mut file3 = at.make_file("testdir/testfile3");
+    file3.write_all(b"content3").unwrap();
+
+    let mut file_list = at.make_file("filelist");
+    write!(file_list, "testfile1\0testfile2\0testdir\0").unwrap();
+
+    ts.ucmd()
+        .arg("--files0-from=filelist")
+        .succeeds()
+        .stdout_contains("testfile1")
+        .stdout_contains("testfile2")
+        .stdout_contains("testdir");
+}
+
+#[test]
+fn test_du_files0_from_stdin() {
+    let ts = TestScenario::new(util_name!());
+    let at = &ts.fixtures;
+
+    let mut file1 = at.make_file("testfile1");
+    file1.write_all(b"content1").unwrap();
+    let mut file2 = at.make_file("testfile2");
+    file2.write_all(b"content2").unwrap();
+
+    let input = "testfile1\0testfile2\0";
+
+    ts.ucmd()
+        .arg("--files0-from=-")
+        .pipe_in(input)
+        .succeeds()
+        .stdout_contains("testfile1")
+        .stdout_contains("testfile2");
+}
+
+#[test]
+fn test_du_files0_from_dir() {
+    let ts = TestScenario::new(util_name!());
+    let at = &ts.fixtures;
+
+    at.mkdir("dir");
+
+    let result = ts.ucmd().arg("--files0-from=dir").fails();
+    assert_eq!(result.stderr_str(), "du: dir: read error: Is a directory\n");
+}