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Niall Pemberton
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Fix IO-168 Symbolic links (symlinks) followed when deleting directory - reported by Apostolos Lerios, thanks to Attila Szegedi for the solution and Brydie McCoy for the patch
git-svn-id: https://svn.apache.org/repos/asf/commons/proper/io/trunk@684715 13f79535-47bb-0310-9956-ffa450edef68
1 parent 7949b2e commit 7bfef47

2 files changed

Lines changed: 284 additions & 1 deletion

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‎src/java/org/apache/commons/io/FileUtils.java‎

Lines changed: 31 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -979,7 +979,10 @@ public static void deleteDirectory(File directory) throws IOException {
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return;
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}
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cleanDirectory(directory);
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if (!isSymlink(directory)) {
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cleanDirectory(directory);
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}
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if (!directory.delete()) {
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String message =
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"Unable to delete directory " + directory + ".";
@@ -1921,4 +1924,31 @@ public static void moveToDirectory(File src, File destDir, boolean createDestDir
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}
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}
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/**
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* Determines whether the specified file is a link rather than an actual file.
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* Will not return true if there is a symlink anywhere in the path, only if the specific file is.
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*
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* @param file the file to check
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* @return true iff the file is a symlink
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* @throws IOException if an IO error occurs while checking the file
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* @since 2.0
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*/
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public static boolean isSymlink(File file) throws IOException {
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if (file == null) {
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throw new NullPointerException("File must not be null");
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}
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File fileInCanonicalDir = null;
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if (file.getParent() == null) {
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fileInCanonicalDir = file;
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} else {
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File canonicalDir = file.getParentFile().getCanonicalFile();
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fileInCanonicalDir = new File(canonicalDir, file.getName());
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}
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if (fileInCanonicalDir.getCanonicalFile().equals(fileInCanonicalDir.getAbsoluteFile())) {
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return false;
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} else {
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return true;
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}
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}
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}

‎src/test/org/apache/commons/io/FileUtilsCleanSymlinksTestCase.java‎

Lines changed: 253 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,253 @@
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/*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership.
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* The ASF licenses this file to You under the Apache License, Version 2.0
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* (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package org.apache.commons.io;
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import org.apache.commons.io.testtools.FileBasedTestCase;
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import java.io.File;
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import java.util.List;
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import java.util.ArrayList;
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import junit.textui.TestRunner;
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import junit.framework.Test;
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import junit.framework.TestSuite;
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/**
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* Test cases for FileUtils.cleanDirectory() method that involve symlinks.
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* & FileUtils.isSymlink(File file)
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*/
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public class FileUtilsCleanSymlinksTestCase extends FileBasedTestCase {
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final File top = getTestDirectory();
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public static void main(String[] args) {
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TestRunner.run(suite());
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}
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public static Test suite() {
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return new TestSuite(FileUtilsCleanSymlinksTestCase.class);
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}
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public FileUtilsCleanSymlinksTestCase(String name) {
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super(name);
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}
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protected void setUp() throws Exception {
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top.mkdirs();
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}
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protected void tearDown() throws Exception {
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FileUtils.deleteDirectory(top);
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}
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public void testCleanDirWithSymlinkFile() throws Exception {
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if (System.getProperty("os.name").startsWith("Win")) {
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// cant create symlinks in windows.
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return;
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}
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final File realOuter = new File(top, "realouter");
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assertTrue(realOuter.mkdirs());
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final File realInner = new File(realOuter, "realinner");
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assertTrue(realInner.mkdirs());
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final File realFile = new File(realInner, "file1");
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FileUtils.touch(realFile);
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assertEquals(1, realInner.list().length);
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final File randomFile = new File(top, "randomfile");
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FileUtils.touch(randomFile);
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final File symlinkFile = new File(realInner, "fakeinner");
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setupSymlink(randomFile, symlinkFile);
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assertEquals(2, realInner.list().length);
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// assert contents of the real directory were removed including the symlink
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FileUtils.cleanDirectory(realOuter);
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assertEquals(0, realOuter.list().length);
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// ensure that the contents of the symlink were NOT removed.
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assertTrue(randomFile.exists());
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assertFalse(symlinkFile.exists());
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}
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public void testCleanDirWithASymlinkDir() throws Exception {
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if (System.getProperty("os.name").startsWith("Win")) {
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// cant create symlinks in windows.
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return;
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}
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final File realOuter = new File(top, "realouter");
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assertTrue(realOuter.mkdirs());
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final File realInner = new File(realOuter, "realinner");
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assertTrue(realInner.mkdirs());
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FileUtils.touch(new File(realInner, "file1"));
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assertEquals(1, realInner.list().length);
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final File randomDirectory = new File(top, "randomDir");
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assertTrue(randomDirectory.mkdirs());
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FileUtils.touch(new File(randomDirectory, "randomfile"));
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assertEquals(1, randomDirectory.list().length);
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final File symlinkDirectory = new File(realOuter, "fakeinner");
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setupSymlink(randomDirectory, symlinkDirectory);
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assertEquals(1, symlinkDirectory.list().length);
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// assert contents of the real directory were removed including the symlink
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FileUtils.cleanDirectory(realOuter);
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assertEquals(0, realOuter.list().length);
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// ensure that the contents of the symlink were NOT removed.
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assertEquals("Contents of sym link should not have been removed", 1, randomDirectory.list().length);
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}
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public void testCleanDirWithParentSymlinks() throws Exception {
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if (System.getProperty("os.name").startsWith("Win")) {
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// cant create symlinks in windows.
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return;
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}
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final File realParent = new File(top, "realparent");
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assertTrue(realParent.mkdirs());
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final File realInner = new File(realParent, "realinner");
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assertTrue(realInner.mkdirs());
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FileUtils.touch(new File(realInner, "file1"));
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assertEquals(1, realInner.list().length);
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final File randomDirectory = new File(top, "randomDir");
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assertTrue(randomDirectory.mkdirs());
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FileUtils.touch(new File(randomDirectory, "randomfile"));
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assertEquals(1, randomDirectory.list().length);
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final File symlinkDirectory = new File(realParent, "fakeinner");
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setupSymlink(randomDirectory, symlinkDirectory);
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assertEquals(1, symlinkDirectory.list().length);
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final File symlinkParentDirectory = new File(top, "fakeouter");
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setupSymlink(realParent, symlinkParentDirectory);
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// assert contents of the real directory were removed including the symlink
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FileUtils.cleanDirectory(symlinkParentDirectory);// should clean the contents of this but not recurse into other links
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assertEquals(0, symlinkParentDirectory.list().length);
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assertEquals(0, realParent.list().length);
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// ensure that the contents of the symlink were NOT removed.
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assertEquals("Contents of sym link should not have been removed", 1, randomDirectory.list().length);
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}
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public void testStillClearsIfGivenDirectoryIsASymlink() throws Exception {
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if (System.getProperty("os.name").startsWith("Win")) {
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// cant create symlinks in windows.
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return;
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}
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final File randomDirectory = new File(top, "randomDir");
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assertTrue(randomDirectory.mkdirs());
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FileUtils.touch(new File(randomDirectory, "randomfile"));
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assertEquals(1, randomDirectory.list().length);
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final File symlinkDirectory = new File(top, "fakeDir");
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setupSymlink(randomDirectory, symlinkDirectory);
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FileUtils.cleanDirectory(symlinkDirectory);
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assertEquals(0, symlinkDirectory.list().length);
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assertEquals(0, randomDirectory.list().length);
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}
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public void testIdentifiesSymlinkDir() throws Exception {
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if (System.getProperty("os.name").startsWith("Win")) {
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// cant create symlinks in windows.
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return;
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}
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final File randomDirectory = new File(top, "randomDir");
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assertTrue(randomDirectory.mkdirs());
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final File symlinkDirectory = new File(top, "fakeDir");
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setupSymlink(randomDirectory, symlinkDirectory);
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assertTrue(FileUtils.isSymlink(symlinkDirectory));
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assertFalse(FileUtils.isSymlink(randomDirectory));
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}
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public void testIdentifiesSymlinkFile() throws Exception {
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if (System.getProperty("os.name").startsWith("Win")) {
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// cant create symlinks in windows.
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return;
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}
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final File randomFile = new File(top, "randomfile");
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FileUtils.touch(randomFile);
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final File symlinkFile = new File(top, "fakeinner");
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setupSymlink(randomFile, symlinkFile);
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assertTrue(FileUtils.isSymlink(symlinkFile));
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assertFalse(FileUtils.isSymlink(randomFile));
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}
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public void testCorrectlyIdentifySymlinkWithParentSymLink() throws Exception {
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if (System.getProperty("os.name").startsWith("Win")) {
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// cant create symlinks in windows.
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return;
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}
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final File realParent = new File(top, "realparent");
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assertTrue(realParent.mkdirs());
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final File symlinkParentDirectory = new File(top, "fakeparent");
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setupSymlink(realParent, symlinkParentDirectory);
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final File realChild = new File(symlinkParentDirectory, "realChild");
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assertTrue(realChild.mkdirs());
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final File symlinkChild = new File(symlinkParentDirectory, "fakeChild");
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setupSymlink(realChild, symlinkChild);
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assertTrue(FileUtils.isSymlink(symlinkChild));
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assertFalse(FileUtils.isSymlink(realChild));
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}
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private void setupSymlink(File res, File link) throws Exception {
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// create symlink
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List args = new ArrayList();
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args.add("ln");
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args.add("-s");
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args.add(res.getAbsolutePath());
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args.add(link.getAbsolutePath());
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Process proc;
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proc = Runtime.getRuntime().exec((String[]) args.toArray(new String[args.size()]));
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proc.waitFor();
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}
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}

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