Add functions to list all file names in a archive

Signed-off-by: asakiz <asakizin@gmail.com>

examples/uncompress.rs

@@ -16,6 +16,7 @@ struct TopLevel {
 #[derive(FromArgs, PartialEq, Debug)]
 #[argh(subcommand)]
 enum CmdLine {
+    ListArchiveFiles(SubCommandListArchiveFiles),
     UncompressData(SubCommandUncompressData),
     UncompressArchiveFile(SubCommandUncompressArchiveFile),
     UncompressArchive(SubCommandUncompressArchive),
@@ -68,10 +69,26 @@ struct SubCommandUncompressArchive {
     preserve_ownership: bool,
 }
 
+#[derive(FromArgs, PartialEq, Debug)]
+/// List archive files subcommand.
+#[argh(subcommand, name = "list-archive-files")]
+struct SubCommandListArchiveFiles {
+    /// source path
+    #[argh(positional)]
+    source_path: String,
+}
+
 fn main() -> compress_tools::Result<()> {
     let cmd: TopLevel = argh::from_env();
 
     match cmd.nested {
+        CmdLine::ListArchiveFiles(input) => {
+            let filename = std::fs::File::open(input.source_path)?;
+
+            let file_list = list_archive_files(filename)?;
+            println!("{:#?}", file_list);
+        }
+
         CmdLine::UncompressData(input) => {
             let mut source = std::fs::File::open(input.source_path)?;
             let mut target = std::fs::File::open(input.target_path)?;

src/lib.rs

@@ -83,6 +83,46 @@ enum Mode {
     WriteDisk { ownership: Ownership },
 }
 
+/// Get all files in a archive using `source` as a reader.
+/// # Example
+///
+/// ```no_run
+/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
+/// use compress_tools::*;
+/// use std::fs::File;
+///
+/// let mut source = File::open("tree.tar")?;
+///
+/// let file_list = list_archive_files(&mut source)?;
+/// # Ok(())
+/// # }
+/// ```
+pub fn list_archive_files<R>(source: R) -> Result<Vec<String>>
+where
+    R: Read,
+{
+    run_with_archive(
+        Mode::AllFormat,
+        source,
+        |archive_reader, _, mut entry| unsafe {
+            let mut file_list = Vec::new();
+            loop {
+                match ffi::archive_read_next_header(archive_reader, &mut entry) {
+                    ffi::ARCHIVE_OK => {
+                        file_list.push(
+                            CStr::from_ptr(ffi::archive_entry_pathname(entry))
+                                .to_str()?
+                                .to_string(),
+                        );
+                    }
+                    ffi::ARCHIVE_EOF => return Ok(file_list),
+                    _ => return Err(Error::from(archive_reader)),
+                }
+            }
+        },
+    )
+}
+
 /// Uncompress a file using the `source` need as reader and the `target` as a
 /// writer.
 ///