#132: untar preserves unix file permissios (#185)

Author: MattesMrzik

cli/src/main/java/com/devonfw/tools/ide/io/FileAccess.java

@@ -62,7 +62,7 @@ public interface FileAccess {
    * Creates a symbolic link. If the given {@code targetLink} already exists and is a symbolic link or a Windows
    * junction, it will be replaced. In case of missing privileges, Windows Junctions may be used as fallback, which must
    * point to absolute paths. Therefore, the created link will be absolute instead of relative.
-   * 
+   *
    * @param source the source {@link Path} to link to, may be relative or absolute.
    * @param targetLink the {@link Path} where the symbolic link shall be created pointing to {@code source}.
    * @param relative - {@code true} if the symbolic link shall be relative, {@code false} if it shall be absolute.
@@ -73,7 +73,7 @@ public interface FileAccess {
    * Creates a relative symbolic link. If the given {@code targetLink} already exists and is a symbolic link or a
    * Windows junction, it will be replaced. In case of missing privileges, Windows Junctions may be used as fallback,
    * which must point to absolute paths. Therefore, the created link will be absolute instead of relative.
-   * 
+   *
    * @param source the source {@link Path} to link to, may be relative or absolute.
    * @param targetLink the {@link Path} where the symbolic link shall be created pointing to {@code source}.
    */

cli/src/main/java/com/devonfw/tools/ide/io/FileAccessImpl.java

@@ -18,19 +18,23 @@
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.nio.file.attribute.BasicFileAttributes;
+import java.nio.file.attribute.PosixFilePermission;
+import java.nio.file.attribute.PosixFilePermissions;
 import java.security.DigestInputStream;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.time.LocalDateTime;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Set;
 import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.stream.Stream;
 
 import org.apache.commons.compress.archivers.ArchiveEntry;
 import org.apache.commons.compress.archivers.ArchiveInputStream;
+import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
 import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;
 import org.apache.commons.compress.archivers.zip.ZipArchiveInputStream;
 
@@ -315,8 +319,7 @@ private void deleteLinkIfExists(Path path) throws IOException {
         return;
       }
     }
-    exists = exists || Files.exists(path); // "||" since broken junctions are not detected by
-                                           // Files.exists(brokenJunction)
+    exists = exists || Files.exists(path);
     boolean isSymlink = exists && Files.isSymbolicLink(path);
 
     assert !(isSymlink && isJunction);
@@ -378,7 +381,7 @@ private Path adaptPath(Path source, Path targetLink, boolean relative) throws IO
 
   /**
    * Creates a Windows junction at {@code targetLink} pointing to {@code source}.
-   * 
+   *
    * @param source must be another Windows junction or a directory.
    * @param targetLink the location of the Windows junction.
    */
@@ -495,12 +498,40 @@ public void untar(Path file, Path targetDir, TarCompression compression) {
     unpack(file, targetDir, in -> new TarArchiveInputStream(compression.unpack(in)));
   }
 
+  /**
+   * @param permissions The integer as returned by {@link TarArchiveEntry#getMode()} that represents the file
+   *        permissions of a file on a Unix file system.
+   * @return A String representing the file permissions. E.g. "rwxrwxr-x" or "rw-rw-r--"
+   */
+  public static String generatePermissionString(int permissions) {
+
+    // Ensure that only the last 9 bits are considered
+    permissions &= 0b111111111;
+
+    StringBuilder permissionStringBuilder = new StringBuilder("rwxrwxrwx");
+
+    for (int i = 0; i < 9; i++) {
+      int mask = 1 << i;
+      char currentChar = ((permissions & mask) != 0) ? permissionStringBuilder.charAt(8 - i) : '-';
+      permissionStringBuilder.setCharAt(8 - i, currentChar);
+    }
+
+    return permissionStringBuilder.toString();
+  }
+
   private void unpack(Path file, Path targetDir, Function<InputStream, ArchiveInputStream> unpacker) {
 
     this.context.trace("Unpacking archive {} to {}", file, targetDir);
     try (InputStream is = Files.newInputStream(file); ArchiveInputStream ais = unpacker.apply(is)) {
       ArchiveEntry entry = ais.getNextEntry();
+      boolean isTar = ais instanceof TarArchiveInputStream;
       while (entry != null) {
+        String permissionStr = null;
+        if (isTar) {
+          int tarMode = ((TarArchiveEntry) entry).getMode();
+          permissionStr = generatePermissionString(tarMode);
+        }
+
         Path entryName = Paths.get(entry.getName());
         Path entryPath = targetDir.resolve(entryName).toAbsolutePath();
         if (!entryPath.startsWith(targetDir)) {
@@ -513,6 +544,10 @@ private void unpack(Path file, Path targetDir, Function<InputStream, ArchiveInpu
           mkdirs(entryPath.getParent());
           Files.copy(ais, entryPath);
         }
+        if (isTar) {
+          Set<PosixFilePermission> permissions = PosixFilePermissions.fromString(permissionStr);
+          Files.setPosixFilePermissions(entryPath, permissions);
+        }
         entry = ais.getNextEntry();
       }
     } catch (IOException e) {

cli/src/test/java/com/devonfw/tools/ide/io/FileAccessImplTest.java

@@ -1,12 +1,16 @@
 package com.devonfw.tools.ide.io;
 
+import static com.devonfw.tools.ide.io.FileAccessImpl.generatePermissionString;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.LinkOption;
 import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
+import java.nio.file.attribute.PosixFilePermission;
+import java.nio.file.attribute.PosixFilePermissions;
+import java.util.Set;
 
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
@@ -325,7 +329,7 @@ private void createSymlinks(FileAccess fa, Path dir, boolean relative) {
 
   /**
    * Checks if the symlinks exist. This is used by the tests of {@link FileAccessImpl#symlink(Path, Path, boolean)}.
-   * 
+   *
    * @param dir the {@link Path} to the directory where the symlinks are expected.
    */
   private void assertSymlinksExist(Path dir) {
@@ -469,4 +473,99 @@ private void assertSymlinkRead(Path link, Path trueTarget) {
           + " and readPath " + readPath, e);
     }
   }
+
+  /**
+   * Test of {@link FileAccessImpl#untar(Path, Path, TarCompression)} with {@link TarCompression#NONE} and checks if
+   * file permissions are preserved on Unix.
+   */
+  @Test
+  public void testUntarWithNoneCompressionWithFilePermissions(@TempDir Path tempDir) {
+
+    // arrange
+    IdeContext context = IdeTestContextMock.get();
+    if (context.getSystemInfo().isWindows()) {
+      return;
+    }
+
+    // act
+    context.getFileAccess().untar(
+        Path.of("src/test/resources/com/devonfw/tools/ide/io").resolve("executable_and_non_executable.tar"), tempDir,
+        TarCompression.NONE);
+
+    // assert
+    assertPosixFilePermissions(tempDir.resolve("executableFile.txt"), "rwxrwxr-x");
+    assertPosixFilePermissions(tempDir.resolve("nonExecutableFile.txt"), "rw-rw-r--");
+  }
+
+  /**
+   * Test of {@link FileAccessImpl#untar(Path, Path, TarCompression)} with {@link TarCompression#GZ} and checks if file
+   * permissions are preserved on Unix.
+   */
+  @Test
+  public void testUntarWithGzCompressionWithFilePermissions(@TempDir Path tempDir) {
+
+    // arrange
+    IdeContext context = IdeTestContextMock.get();
+    if (context.getSystemInfo().isWindows()) {
+      return;
+    }
+
+    // act
+    context.getFileAccess().untar(
+        Path.of("src/test/resources/com/devonfw/tools/ide/io").resolve("executable_and_non_executable.tar.gz"), tempDir,
+        TarCompression.GZ);
+
+    // assert
+    assertPosixFilePermissions(tempDir.resolve("executableFile.txt"), "rwxrwxr-x");
+    assertPosixFilePermissions(tempDir.resolve("nonExecutableFile.txt"), "rw-rw-r--");
+  }
+
+  /**
+   * Test of {@link FileAccessImpl#untar(Path, Path, TarCompression)} with {@link TarCompression#BZIP2} and checks if
+   * file permissions are preserved on Unix.
+   */
+  @Test
+  public void testUntarWithBzip2CompressionWithFilePermissions(@TempDir Path tempDir) {
+
+    // arrange
+    IdeContext context = IdeTestContextMock.get();
+    if (context.getSystemInfo().isWindows()) {
+      return;
+    }
+
+    // act
+    context.getFileAccess().untar(
+        Path.of("src/test/resources/com/devonfw/tools/ide/io").resolve("executable_and_non_executable.tar.bz2"),
+        tempDir, TarCompression.BZIP2);
+
+    // assert
+    assertPosixFilePermissions(tempDir.resolve("executableFile.txt"), "rwxrwxr-x");
+    assertPosixFilePermissions(tempDir.resolve("nonExecutableFile.txt"), "rw-rw-r--");
+  }
+
+  private void assertPosixFilePermissions(Path file, String permissions) {
+
+    try {
+      Set<PosixFilePermission> posixPermissions = Files.getPosixFilePermissions(file);
+      String permissionStr = PosixFilePermissions.toString(posixPermissions);
+      assertThat(permissions).isEqualTo(permissionStr);
+    } catch (IOException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  /**
+   * Test of {@link FileAccessImpl#generatePermissionString(int)}.
+   */
+  @Test
+  public void testGeneratePermissionString() {
+
+    assertThat(generatePermissionString(0)).isEqualTo("---------");
+    assertThat(generatePermissionString(436)).isEqualTo("rw-rw-r--");
+    assertThat(generatePermissionString(948)).isEqualTo("rw-rw-r--");
+    assertThat(generatePermissionString(509)).isEqualTo("rwxrwxr-x");
+    assertThat(generatePermissionString(511)).isEqualTo("rwxrwxrwx");
+
+  }
+
 }