Absolute Paths Support for Archives Creation (#291)

Added support for -P and --absolute-names flags to preserve absolute
paths when creating archives, matching GNU tar behavior.

* CLI: Added -P / --absolute-names options to uu_app.
* Operations: Configured tar::Builder to preserve absolute paths
  based on the new flag.
* Normalization: Updated normalize_path to skip stripping root
  and prefix components when absolute paths are allowed.
* Tests: Added integration tests for path preservation and trimming
  during archive creation and extraction.

src/uu/tar/src/operations/create.rs

@@ -18,6 +18,7 @@ use uucore::error::UResult;
 ///
 /// * `archive_path` - Path where the tar archive should be created
 /// * `files` - Slice of file paths to add to the archive
+/// * `allow_absolute` - Allow absolute paths while creating archive
 /// * `verbose` - Whether to print verbose output during creation
 ///
 /// # Errors
@@ -26,7 +27,12 @@ use uucore::error::UResult;
 /// - The archive file cannot be created
 /// - Any input file cannot be read
 /// - Files cannot be added due to I/O or permission errors
-pub fn create_archive(archive_path: &Path, files: &[&Path], verbose: bool) -> UResult<()> {
+pub fn create_archive(
+    archive_path: &Path,
+    files: &[&Path],
+    allow_absolute: bool,
+    verbose: bool,
+) -> UResult<()> {
     // Create the output file
     let file = File::create(archive_path).map_err(|e| TarError::CannotCreateArchive {
         path: archive_path.to_path_buf(),
@@ -35,6 +41,8 @@ pub fn create_archive(archive_path: &Path, files: &[&Path], verbose: bool) -> UR
 
     // Create Builder instance
     let mut builder = Builder::new(file);
+    builder.preserve_absolute(allow_absolute);
+
     let mut out = BufWriter::new(io::stdout().lock());
 
     // Add each file or directory to the archive
@@ -64,7 +72,7 @@ pub fn create_archive(archive_path: &Path, files: &[&Path], verbose: bool) -> UR
         }
 
         // Normalize path if needed (so far, handles only absolute paths)
-        let normalized_name = if let Some(normalized) = normalize_path(path) {
+        let normalized_name = if let Some(normalized) = normalize_path(path, allow_absolute) {
             let original_components: Vec<Component> = path.components().collect();
             let normalized_components: Vec<Component> = normalized.components().collect();
             if original_components.len() > normalized_components.len() {
@@ -129,8 +137,8 @@ fn get_tree(path: &Path) -> Result<Vec<PathBuf>, std::io::Error> {
     Ok(paths)
 }
 
-fn normalize_path(path: &Path) -> Option<PathBuf> {
-    if path.is_absolute() {
+fn normalize_path(path: &Path, allow_absolute: bool) -> Option<PathBuf> {
+    if path.is_absolute() && !allow_absolute {
         Some(
             path.components()
                 .filter(|c| !matches!(c, RootDir | ParentDir | Prefix(_)))

src/uu/tar/src/tar.rs

@@ -131,6 +131,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     };
 
     let verbose = matches.get_flag("verbose");
+    let allow_absolute = matches.get_flag("absolute-names");
 
     // Handle extract operation
     if matches.get_flag("extract") {
@@ -159,7 +160,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
             ));
         }
 
-        return operations::create::create_archive(archive_path, &files, verbose);
+        return operations::create::create_archive(archive_path, &files, allow_absolute, verbose);
     }
 
     // Handle list operation
@@ -199,6 +200,10 @@ pub fn uu_app() -> Command {
             // Archive file
             arg!(-f --file <ARCHIVE> "Use archive file or device ARCHIVE")
                 .value_parser(clap::value_parser!(PathBuf)),
+            arg!(
+                -P --"absolute-names"
+                "Don't strip leading '/'s from file names"
+            ),
             // Compression options
             // arg!(-z --gzip "Filter through gzip"),
             // arg!(-j --bzip2 "Filter through bzip2"),
@@ -207,7 +212,6 @@ pub fn uu_app() -> Command {
             arg!(-v --verbose "Verbosely list files processed"),
             // arg!(-h --dereference "Follow symlinks"),
             // arg!(-p --"preserve-permissions" "Extract information about file permissions"),
-            // arg!(-P --"absolute-names" "Don't strip leading '/' from file names"),
             // Help
             arg!(--help "Print help information").action(ArgAction::Help),
             // Files to process

tests/by-util/test_tar.rs

@@ -171,11 +171,55 @@ fn test_create_absolute_path() {
     file_abs_path.push("file1.txt");
 
     at.write(&file_abs_path.display().to_string(), "content1");
-    ucmd.args(&["-cf", "archive.tar", &file_abs_path.display().to_string()])
-        .succeeds()
-        .stdout_contains("Removing leading");
 
-    assert!(at.file_exists("archive.tar"));
+    // Trim leading '/'
+    ucmd.args(&[
+        "-cf",
+        "archive-trimed.tar",
+        &file_abs_path.display().to_string(),
+    ])
+    .succeeds()
+    .stdout_contains("Removing leading");
+
+    assert!(at.file_exists("archive-trimed.tar"));
+
+    let expected_trimmed_path = file_abs_path
+        .components()
+        .filter(|c| !matches!(c, path::Component::RootDir | path::Component::Prefix(_)))
+        .map(|c| c.as_os_str().display().to_string())
+        .collect::<Vec<_>>()
+        .join("/");
+
+    new_ucmd!()
+        .args(&["-tf", "archive-trimed.tar"])
+        .current_dir(at.as_string())
+        .succeeds()
+        .stdout_contains(&expected_trimmed_path);
+
+    let (at, mut ucmd) = at_and_ucmd!();
+    // Preserve leading '/'
+    ucmd.args(&[
+        "-cPf",
+        "archive-preserved.tar",
+        &file_abs_path.display().to_string(),
+    ])
+    .succeeds()
+    .no_output();
+
+    assert!(at.file_exists("archive-preserved.tar"));
+
+    let expected_prefix = file_abs_path
+        .components()
+        .find(|c| matches!(c, path::Component::RootDir | path::Component::Prefix(_)))
+        .map(|c| c.as_os_str().display().to_string())
+        .unwrap();
+
+    new_ucmd!()
+        .args(&["-tf", "archive-preserved.tar"])
+        .current_dir(at.as_string())
+        .succeeds()
+        .stdout_contains(expected_prefix)
+        .stdout_contains(expected_trimmed_path);
 }
 
 // Extract operation tests
@@ -554,11 +598,15 @@ fn test_extract_created_from_absolute_path() {
     file_abs_path.push("file1.txt");
 
     at.write(&file_abs_path.display().to_string(), "content1");
-    ucmd.args(&["-cf", "archive.tar", &file_abs_path.display().to_string()])
-        .succeeds();
+    ucmd.args(&[
+        "-cf",
+        "archive-trimed.tar",
+        &file_abs_path.display().to_string(),
+    ])
+    .succeeds();
 
     new_ucmd!()
-        .args(&["-xf", "archive.tar"])
+        .args(&["-xf", "archive-trimed.tar"])
         .current_dir(at.as_string())
         .succeeds();
 
@@ -569,6 +617,23 @@ fn test_extract_created_from_absolute_path() {
         .collect::<Vec<_>>()
         .join(std::path::MAIN_SEPARATOR_STR);
 
+    assert!(at.file_exists(&expected_path));
+
+    new_ucmd!()
+        .args(&[
+            "-cPf",
+            "archive-preserved.tar",
+            &file_abs_path.display().to_string(),
+        ])
+        .current_dir(at.as_string())
+        .succeeds();
+
+    at.remove(&expected_path);
+    new_ucmd!()
+        .args(&["-xf", "archive-preserved.tar"])
+        .current_dir(at.as_string())
+        .succeeds();
+
     assert!(at.file_exists(expected_path));
 }