com.buaa.cfs.utils.FileUtil.java Source code

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/**
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE
 * file distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 */

package com.buaa.cfs.utils;

import com.buaa.cfs.conf.Configuration;
import com.buaa.cfs.fs.FileContext;
import com.buaa.cfs.fs.FileStatus;
import com.buaa.cfs.fs.Path;
import com.buaa.cfs.fs.FileSystem;
import com.buaa.cfs.fs.permission.FsAction;
import com.buaa.cfs.fs.permission.FsPermission;
import com.buaa.cfs.io.nativeio.NativeIO;
import org.apache.commons.collections.map.CaseInsensitiveMap;
import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.io.*;
import java.util.*;
import java.util.jar.Attributes;
import java.util.jar.JarOutputStream;
import java.util.jar.Manifest;
import java.util.zip.GZIPInputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

/**
 * A collection of file-processing util methods
 */
public class FileUtil {

    private static final Log LOG = LogFactory.getLog(FileUtil.class);

    /* The error code is defined in winutils to indicate insufficient
     * privilege to create symbolic links. This value need to keep in
     * sync with the constant of the same name in:
     * "src\winutils\common.h"
     * */
    public static final int SYMLINK_NO_PRIVILEGE = 2;

    /**
     * convert an array of FileStatus to an array of Path
     *
     * @param stats an array of FileStatus objects
     *
     * @return an array of paths corresponding to the input
     */
    public static Path[] stat2Paths(FileStatus[] stats) {
        if (stats == null)
            return null;
        Path[] ret = new Path[stats.length];
        for (int i = 0; i < stats.length; ++i) {
            ret[i] = stats[i].getPath();
        }
        return ret;
    }

    /**
     * convert an array of FileStatus to an array of Path. If stats if null, return path
     *
     * @param stats an array of FileStatus objects
     * @param path  default path to return in stats is null
     *
     * @return an array of paths corresponding to the input
     */
    public static Path[] stat2Paths(FileStatus[] stats, Path path) {
        if (stats == null)
            return new Path[] { path };
        else
            return stat2Paths(stats);
    }

    /**
     * Delete a directory and all its contents.  If we return false, the directory may be partially-deleted. (1) If dir
     * is symlink to a file, the symlink is deleted. The file pointed to by the symlink is not deleted. (2) If dir is
     * symlink to a directory, symlink is deleted. The directory pointed to by symlink is not deleted. (3) If dir is a
     * normal file, it is deleted. (4) If dir is a normal directory, then dir and all its contents recursively are
     * deleted.
     */
    public static boolean fullyDelete(final File dir) {
        return fullyDelete(dir, false);
    }

    /**
     * Delete a directory and all its contents.  If we return false, the directory may be partially-deleted. (1) If dir
     * is symlink to a file, the symlink is deleted. The file pointed to by the symlink is not deleted. (2) If dir is
     * symlink to a directory, symlink is deleted. The directory pointed to by symlink is not deleted. (3) If dir is a
     * normal file, it is deleted. (4) If dir is a normal directory, then dir and all its contents recursively are
     * deleted.
     *
     * @param dir                 the file or directory to be deleted
     * @param tryGrantPermissions true if permissions should be modified to delete a file.
     *
     * @return true on success false on failure.
     */
    public static boolean fullyDelete(final File dir, boolean tryGrantPermissions) {
        if (tryGrantPermissions) {
            // try to chmod +rwx the parent folder of the 'dir':
            File parent = dir.getParentFile();
            grantPermissions(parent);
        }
        if (deleteImpl(dir, false)) {
            // dir is (a) normal file, (b) symlink to a file, (c) empty directory or
            // (d) symlink to a directory
            return true;
        }
        // handle nonempty directory deletion
        if (!fullyDeleteContents(dir, tryGrantPermissions)) {
            return false;
        }
        return deleteImpl(dir, true);
    }

    /**
     * Returns the target of the given symlink. Returns the empty string if the given path does not refer to a symlink
     * or there is an error accessing the symlink.
     *
     * @param f File representing the symbolic link.
     *
     * @return The target of the symbolic link, empty string on error or if not a symlink.
     */
    public static String readLink(File f) {
        /* NB: Use readSymbolicLink in java.nio.file.Path once available. Could
         * use getCanonicalPath in File to get the target of the symlink but that
         * does not indicate if the given path refers to a symlink.
         */
        try {
            return Shell.execCommand(Shell.getReadlinkCommand(f.toString())).trim();
        } catch (IOException x) {
            return "";
        }
    }

    /*
     * Pure-Java implementation of "chmod +rwx f".
     */
    private static void grantPermissions(final File f) {
        FileUtil.setExecutable(f, true);
        FileUtil.setReadable(f, true);
        FileUtil.setWritable(f, true);
    }

    private static boolean deleteImpl(final File f, final boolean doLog) {
        if (f == null) {
            LOG.warn("null file argument.");
            return false;
        }
        final boolean wasDeleted = f.delete();
        if (wasDeleted) {
            return true;
        }
        final boolean ex = f.exists();
        if (doLog && ex) {
            LOG.warn("Failed to delete file or dir [" + f.getAbsolutePath() + "]: it still exists.");
        }
        return !ex;
    }

    /**
     * Delete the contents of a directory, not the directory itself.  If we return false, the directory may be
     * partially-deleted. If dir is a symlink to a directory, all the contents of the actual directory pointed to by dir
     * will be deleted.
     */
    public static boolean fullyDeleteContents(final File dir) {
        return fullyDeleteContents(dir, false);
    }

    /**
     * Delete the contents of a directory, not the directory itself.  If we return false, the directory may be
     * partially-deleted. If dir is a symlink to a directory, all the contents of the actual directory pointed to by dir
     * will be deleted.
     *
     * @param tryGrantPermissions if 'true', try grant +rwx permissions to this and all the underlying directories
     *                            before trying to delete their contents.
     */
    public static boolean fullyDeleteContents(final File dir, final boolean tryGrantPermissions) {
        if (tryGrantPermissions) {
            // to be able to list the dir and delete files from it
            // we must grant the dir rwx permissions:
            grantPermissions(dir);
        }
        boolean deletionSucceeded = true;
        final File[] contents = dir.listFiles();
        if (contents != null) {
            for (int i = 0; i < contents.length; i++) {
                if (contents[i].isFile()) {
                    if (!deleteImpl(contents[i], true)) {// normal file or symlink to another file
                        deletionSucceeded = false;
                        continue; // continue deletion of other files/dirs under dir
                    }
                } else {
                    // Either directory or symlink to another directory.
                    // Try deleting the directory as this might be a symlink
                    boolean b = false;
                    b = deleteImpl(contents[i], false);
                    if (b) {
                        //this was indeed a symlink or an empty directory
                        continue;
                    }
                    // if not an empty directory or symlink let
                    // fullydelete handle it.
                    if (!fullyDelete(contents[i], tryGrantPermissions)) {
                        deletionSucceeded = false;
                        // continue deletion of other files/dirs under dir
                    }
                }
            }
        }
        return deletionSucceeded;
    }

    //
    // If the destination is a subdirectory of the source, then
    // generate exception
    //
    private static void checkDependencies(FileSystem srcFS, Path src, FileSystem dstFS, Path dst)
            throws IOException {
        if (srcFS == dstFS) {
            String srcq = src.makeQualified(srcFS).toString() + Path.SEPARATOR;
            String dstq = dst.makeQualified(dstFS).toString() + Path.SEPARATOR;
            if (dstq.startsWith(srcq)) {
                if (srcq.length() == dstq.length()) {
                    throw new IOException("Cannot copy " + src + " to itself.");
                } else {
                    throw new IOException("Cannot copy " + src + " to its subdirectory " + dst);
                }
            }
        }
    }

    /** Copy files between FileSystems. */
    public static boolean copy(FileSystem srcFS, Path src, FileSystem dstFS, Path dst, boolean deleteSource,
            Configuration conf) throws IOException {
        return copy(srcFS, src, dstFS, dst, deleteSource, true, conf);
    }

    public static boolean copy(FileSystem srcFS, Path[] srcs, FileSystem dstFS, Path dst, boolean deleteSource,
            boolean overwrite, Configuration conf) throws IOException {
        boolean gotException = false;
        boolean returnVal = true;
        StringBuilder exceptions = new StringBuilder();

        if (srcs.length == 1)
            return copy(srcFS, srcs[0], dstFS, dst, deleteSource, overwrite, conf);

        // Check if dest is directory
        if (!dstFS.exists(dst)) {
            throw new IOException("`" + dst + "': specified destination directory " + "does not exist");
        } else {
            FileStatus sdst = dstFS.getFileStatus(dst);
            if (!sdst.isDirectory())
                throw new IOException("copying multiple files, but last argument `" + dst + "' is not a directory");
        }

        for (Path src : srcs) {
            try {
                if (!copy(srcFS, src, dstFS, dst, deleteSource, overwrite, conf))
                    returnVal = false;
            } catch (IOException e) {
                gotException = true;
                exceptions.append(e.getMessage());
                exceptions.append("\n");
            }
        }
        if (gotException) {
            throw new IOException(exceptions.toString());
        }
        return returnVal;
    }

    /** Copy files between FileSystems. */
    public static boolean copy(FileSystem srcFS, Path src, FileSystem dstFS, Path dst, boolean deleteSource,
            boolean overwrite, Configuration conf) throws IOException {
        FileStatus fileStatus = srcFS.getFileStatus(src);
        return copy(srcFS, fileStatus, dstFS, dst, deleteSource, overwrite, conf);
    }

    /** Copy files between FileSystems. */
    public static boolean copy(FileSystem srcFS, FileStatus srcStatus, FileSystem dstFS, Path dst,
            boolean deleteSource, boolean overwrite, Configuration conf) throws IOException {
        Path src = srcStatus.getPath();
        dst = checkDest(src.getName(), dstFS, dst, overwrite);
        if (srcStatus.isDirectory()) {
            checkDependencies(srcFS, src, dstFS, dst);
            if (!dstFS.mkdirs(dst)) {
                return false;
            }
            FileStatus contents[] = srcFS.listStatus(src);
            for (int i = 0; i < contents.length; i++) {
                copy(srcFS, contents[i], dstFS, new Path(dst, contents[i].getPath().getName()), deleteSource,
                        overwrite, conf);
            }
        } else {
            InputStream in = null;
            OutputStream out = null;
            try {
                in = srcFS.open(src);
                out = dstFS.create(dst, overwrite);
                IOUtils.copyBytes(in, out, conf, true);
            } catch (IOException e) {
                IOUtils.closeStream(out);
                IOUtils.closeStream(in);
                throw e;
            }
        }
        if (deleteSource) {
            return srcFS.delete(src, true);
        } else {
            return true;
        }

    }

    /** Copy all files in a directory to one output file (merge). */
    public static boolean copyMerge(FileSystem srcFS, Path srcDir, FileSystem dstFS, Path dstFile,
            boolean deleteSource, Configuration conf, String addString) throws IOException {
        dstFile = checkDest(srcDir.getName(), dstFS, dstFile, false);

        if (!srcFS.getFileStatus(srcDir).isDirectory())
            return false;

        OutputStream out = dstFS.create(dstFile);

        try {
            FileStatus contents[] = srcFS.listStatus(srcDir);
            Arrays.sort(contents);
            for (int i = 0; i < contents.length; i++) {
                if (contents[i].isFile()) {
                    InputStream in = srcFS.open(contents[i].getPath());
                    try {
                        IOUtils.copyBytes(in, out, conf, false);
                        if (addString != null)
                            out.write(addString.getBytes("UTF-8"));

                    } finally {
                        in.close();
                    }
                }
            }
        } finally {
            out.close();
        }

        if (deleteSource) {
            return srcFS.delete(srcDir, true);
        } else {
            return true;
        }
    }

    /** Copy local files to a FileSystem. */
    public static boolean copy(File src, FileSystem dstFS, Path dst, boolean deleteSource, Configuration conf)
            throws IOException {
        dst = checkDest(src.getName(), dstFS, dst, false);

        if (src.isDirectory()) {
            if (!dstFS.mkdirs(dst)) {
                return false;
            }
            File contents[] = listFiles(src);
            for (int i = 0; i < contents.length; i++) {
                copy(contents[i], dstFS, new Path(dst, contents[i].getName()), deleteSource, conf);
            }
        } else if (src.isFile()) {
            InputStream in = null;
            OutputStream out = null;
            try {
                in = new FileInputStream(src);
                out = dstFS.create(dst);
                IOUtils.copyBytes(in, out, conf);
            } catch (IOException e) {
                IOUtils.closeStream(out);
                IOUtils.closeStream(in);
                throw e;
            }
        } else {
            throw new IOException(src.toString() + ": No such file or directory");
        }
        if (deleteSource) {
            return FileUtil.fullyDelete(src);
        } else {
            return true;
        }
    }

    /** Copy FileSystem files to local files. */
    public static boolean copy(FileSystem srcFS, Path src, File dst, boolean deleteSource, Configuration conf)
            throws IOException {
        FileStatus filestatus = srcFS.getFileStatus(src);
        return copy(srcFS, filestatus, dst, deleteSource, conf);
    }

    /** Copy FileSystem files to local files. */
    private static boolean copy(FileSystem srcFS, FileStatus srcStatus, File dst, boolean deleteSource,
            Configuration conf) throws IOException {
        Path src = srcStatus.getPath();
        if (srcStatus.isDirectory()) {
            if (!dst.mkdirs()) {
                return false;
            }
            FileStatus contents[] = srcFS.listStatus(src);
            for (int i = 0; i < contents.length; i++) {
                copy(srcFS, contents[i], new File(dst, contents[i].getPath().getName()), deleteSource, conf);
            }
        } else {
            InputStream in = srcFS.open(src);
            IOUtils.copyBytes(in, new FileOutputStream(dst), conf);
        }
        if (deleteSource) {
            return srcFS.delete(src, true);
        } else {
            return true;
        }
    }

    private static Path checkDest(String srcName, FileSystem dstFS, Path dst, boolean overwrite)
            throws IOException {
        if (dstFS.exists(dst)) {
            FileStatus sdst = dstFS.getFileStatus(dst);
            if (sdst.isDirectory()) {
                if (null == srcName) {
                    throw new IOException("Target " + dst + " is a directory");
                }
                return checkDest(null, dstFS, new Path(dst, srcName), overwrite);
            } else if (!overwrite) {
                throw new IOException("Target " + dst + " already exists");
            }
        }
        return dst;
    }

    /**
     * Convert a os-native filename to a path that works for the shell.
     *
     * @param filename The filename to convert
     *
     * @return The unix pathname
     *
     * @throws IOException on windows, there can be problems with the subprocess
     */
    public static String makeShellPath(String filename) throws IOException {
        return filename;
    }

    /**
     * Convert a os-native filename to a path that works for the shell.
     *
     * @param file The filename to convert
     *
     * @return The unix pathname
     *
     * @throws IOException on windows, there can be problems with the subprocess
     */
    public static String makeShellPath(File file) throws IOException {
        return makeShellPath(file, false);
    }

    /**
     * Convert a os-native filename to a path that works for the shell.
     *
     * @param file              The filename to convert
     * @param makeCanonicalPath Whether to make canonical path for the file passed
     *
     * @return The unix pathname
     *
     * @throws IOException on windows, there can be problems with the subprocess
     */
    public static String makeShellPath(File file, boolean makeCanonicalPath) throws IOException {
        if (makeCanonicalPath) {
            return makeShellPath(file.getCanonicalPath());
        } else {
            return makeShellPath(file.toString());
        }
    }

    /**
     * Takes an input dir and returns the du on that local directory. Very basic implementation.
     *
     * @param dir The input dir to get the disk space of this local dir
     *
     * @return The total disk space of the input local directory
     */
    public static long getDU(File dir) {
        long size = 0;
        if (!dir.exists())
            return 0;
        if (!dir.isDirectory()) {
            return dir.length();
        } else {
            File[] allFiles = dir.listFiles();
            if (allFiles != null) {
                for (int i = 0; i < allFiles.length; i++) {
                    boolean isSymLink;
                    try {
                        isSymLink = org.apache.commons.io.FileUtils.isSymlink(allFiles[i]);
                    } catch (IOException ioe) {
                        isSymLink = true;
                    }
                    if (!isSymLink) {
                        size += getDU(allFiles[i]);
                    }
                }
            }
            return size;
        }
    }

    /**
     * Given a File input it will unzip the file in a the unzip directory passed as the second parameter
     *
     * @param inFile   The zip file as input
     * @param unzipDir The unzip directory where to unzip the zip file.
     *
     * @throws IOException
     */
    public static void unZip(File inFile, File unzipDir) throws IOException {
        Enumeration<? extends ZipEntry> entries;
        ZipFile zipFile = new ZipFile(inFile);

        try {
            entries = zipFile.entries();
            while (entries.hasMoreElements()) {
                ZipEntry entry = entries.nextElement();
                if (!entry.isDirectory()) {
                    InputStream in = zipFile.getInputStream(entry);
                    try {
                        File file = new File(unzipDir, entry.getName());
                        if (!file.getParentFile().mkdirs()) {
                            if (!file.getParentFile().isDirectory()) {
                                throw new IOException("Mkdirs failed to create " + file.getParentFile().toString());
                            }
                        }
                        OutputStream out = new FileOutputStream(file);
                        try {
                            byte[] buffer = new byte[8192];
                            int i;
                            while ((i = in.read(buffer)) != -1) {
                                out.write(buffer, 0, i);
                            }
                        } finally {
                            out.close();
                        }
                    } finally {
                        in.close();
                    }
                }
            }
        } finally {
            zipFile.close();
        }
    }

    /**
     * Given a Tar File as input it will untar the file in a the untar directory passed as the second parameter
     * <p>
     * This utility will untar ".tar" files and ".tar.gz","tgz" files.
     *
     * @param inFile   The tar file as input.
     * @param untarDir The untar directory where to untar the tar file.
     *
     * @throws IOException
     */
    public static void unTar(File inFile, File untarDir) throws IOException {
        if (!untarDir.mkdirs()) {
            if (!untarDir.isDirectory()) {
                throw new IOException("Mkdirs failed to create " + untarDir);
            }
        }

        boolean gzipped = inFile.toString().endsWith("gz");
        if (Shell.WINDOWS) {
            // Tar is not native to Windows. Use simple Java based implementation for
            // tests and simple tar archives
            unTarUsingJava(inFile, untarDir, gzipped);
        } else {
            // spawn tar utility to untar archive for full fledged unix behavior such
            // as resolving symlinks in tar archives
            unTarUsingTar(inFile, untarDir, gzipped);
        }
    }

    private static void unTarUsingTar(File inFile, File untarDir, boolean gzipped) throws IOException {
        StringBuffer untarCommand = new StringBuffer();
        if (gzipped) {
            untarCommand.append(" gzip -dc '");
            untarCommand.append(FileUtil.makeShellPath(inFile));
            untarCommand.append("' | (");
        }
        untarCommand.append("cd '");
        untarCommand.append(FileUtil.makeShellPath(untarDir));
        untarCommand.append("' ; ");
        untarCommand.append("tar -xf ");

        if (gzipped) {
            untarCommand.append(" -)");
        } else {
            untarCommand.append(FileUtil.makeShellPath(inFile));
        }
        String[] shellCmd = { "bash", "-c", untarCommand.toString() };
        Shell.ShellCommandExecutor shexec = new Shell.ShellCommandExecutor(shellCmd);
        shexec.execute();
        int exitcode = shexec.getExitCode();
        if (exitcode != 0) {
            throw new IOException(
                    "Error untarring file " + inFile + ". Tar process exited with exit code " + exitcode);
        }
    }

    private static void unTarUsingJava(File inFile, File untarDir, boolean gzipped) throws IOException {
        InputStream inputStream = null;
        TarArchiveInputStream tis = null;
        try {
            if (gzipped) {
                inputStream = new BufferedInputStream(new GZIPInputStream(new FileInputStream(inFile)));
            } else {
                inputStream = new BufferedInputStream(new FileInputStream(inFile));
            }

            tis = new TarArchiveInputStream(inputStream);

            for (TarArchiveEntry entry = tis.getNextTarEntry(); entry != null;) {
                unpackEntries(tis, entry, untarDir);
                entry = tis.getNextTarEntry();
            }
        } finally {
            IOUtils.cleanup(LOG, tis, inputStream);
        }
    }

    private static void unpackEntries(TarArchiveInputStream tis, TarArchiveEntry entry, File outputDir)
            throws IOException {
        if (entry.isDirectory()) {
            File subDir = new File(outputDir, entry.getName());
            if (!subDir.mkdirs() && !subDir.isDirectory()) {
                throw new IOException("Mkdirs failed to create tar internal dir " + outputDir);
            }

            for (TarArchiveEntry e : entry.getDirectoryEntries()) {
                unpackEntries(tis, e, subDir);
            }

            return;
        }

        File outputFile = new File(outputDir, entry.getName());
        if (!outputFile.getParentFile().exists()) {
            if (!outputFile.getParentFile().mkdirs()) {
                throw new IOException("Mkdirs failed to create tar internal dir " + outputDir);
            }
        }

        int count;
        byte data[] = new byte[2048];
        BufferedOutputStream outputStream = new BufferedOutputStream(new FileOutputStream(outputFile));

        while ((count = tis.read(data)) != -1) {
            outputStream.write(data, 0, count);
        }

        outputStream.flush();
        outputStream.close();
    }

    /**
     * Create a soft link between a src and destination only on a local disk. HDFS does not support this. On Windows,
     * when symlink creation fails due to security setting, we will log a warning. The return code in this case is 2.
     *
     * @param target   the target for symlink
     * @param linkname the symlink
     *
     * @return 0 on success
     */
    public static int symLink(String target, String linkname) throws IOException {
        // Run the input paths through Java's File so that they are converted to the
        // native OS form
        File targetFile = new File(Path.getPathWithoutSchemeAndAuthority(new Path(target)).toString());
        File linkFile = new File(Path.getPathWithoutSchemeAndAuthority(new Path(linkname)).toString());

        // If not on Java7+, copy a file instead of creating a symlink since
        // Java6 has close to no support for symlinks on Windows. Specifically
        // File#length and File#renameTo do not work as expected.
        // (see HADOOP-9061 for additional details)
        // We still create symlinks for directories, since the scenario in this
        // case is different. The directory content could change in which
        // case the symlink loses its purpose (for example task attempt log folder
        // is symlinked under userlogs and userlogs are generated afterwards).
        if (Shell.WINDOWS && !Shell.isJava7OrAbove() && targetFile.isFile()) {
            try {
                LOG.warn("FileUtil#symlink: On Windows+Java6, copying file instead "
                        + "of creating a symlink. Copying " + target + " -> " + linkname);

                if (!linkFile.getParentFile().exists()) {
                    LOG.warn("Parent directory " + linkFile.getParent() + " does not exist.");
                    return 1;
                } else {
                    org.apache.commons.io.FileUtils.copyFile(targetFile, linkFile);
                }
            } catch (IOException ex) {
                LOG.warn("FileUtil#symlink failed to copy the file with error: " + ex.getMessage());
                // Exit with non-zero exit code
                return 1;
            }
            return 0;
        }

        String[] cmd = Shell.getSymlinkCommand(targetFile.toString(), linkFile.toString());

        Shell.ShellCommandExecutor shExec;
        try {
            if (Shell.WINDOWS && linkFile.getParentFile() != null && !new Path(target).isAbsolute()) {
                // Relative links on Windows must be resolvable at the time of
                // creation. To ensure this we run the shell command in the directory
                // of the link.
                //
                shExec = new Shell.ShellCommandExecutor(cmd, linkFile.getParentFile());
            } else {
                shExec = new Shell.ShellCommandExecutor(cmd);
            }
            shExec.execute();
        } catch (Shell.ExitCodeException ec) {
            int returnVal = ec.getExitCode();
            if (Shell.WINDOWS && returnVal == SYMLINK_NO_PRIVILEGE) {
                LOG.warn("Fail to create symbolic links on Windows. "
                        + "The default security settings in Windows disallow non-elevated "
                        + "administrators and all non-administrators from creating symbolic links. "
                        + "This behavior can be changed in the Local Security Policy management console");
            } else if (returnVal != 0) {
                LOG.warn("Command '" + StringUtils.join(" ", cmd) + "' failed " + returnVal + " with: "
                        + ec.getMessage());
            }
            return returnVal;
        } catch (IOException e) {
            if (LOG.isDebugEnabled()) {
                LOG.debug("Error while create symlink " + linkname + " to " + target + "." + " Exception: "
                        + StringUtils.stringifyException(e));
            }
            throw e;
        }
        return shExec.getExitCode();
    }

    /**
     * Change the permissions on a filename.
     *
     * @param filename the name of the file to change
     * @param perm     the permission string
     *
     * @return the exit code from the command
     *
     * @throws IOException
     * @throws InterruptedException
     */
    public static int chmod(String filename, String perm) throws IOException, InterruptedException {
        return chmod(filename, perm, false);
    }

    /**
     * Change the permissions on a file / directory, recursively, if needed.
     *
     * @param filename  name of the file whose permissions are to change
     * @param perm      permission string
     * @param recursive true, if permissions should be changed recursively
     *
     * @return the exit code from the command.
     *
     * @throws IOException
     */
    public static int chmod(String filename, String perm, boolean recursive) throws IOException {
        String[] cmd = Shell.getSetPermissionCommand(perm, recursive);
        String[] args = new String[cmd.length + 1];
        System.arraycopy(cmd, 0, args, 0, cmd.length);
        args[cmd.length] = new File(filename).getPath();
        Shell.ShellCommandExecutor shExec = new Shell.ShellCommandExecutor(args);
        try {
            shExec.execute();
        } catch (IOException e) {
            if (LOG.isDebugEnabled()) {
                LOG.debug("Error while changing permission : " + filename + " Exception: "
                        + StringUtils.stringifyException(e));
            }
        }
        return shExec.getExitCode();
    }

    /**
     * Set the ownership on a file / directory. User name and group name cannot both be null.
     *
     * @param file      the file to change
     * @param username  the new user owner name
     * @param groupname the new group owner name
     *
     * @throws IOException
     */
    public static void setOwner(File file, String username, String groupname) throws IOException {
        if (username == null && groupname == null) {
            throw new IOException("username == null && groupname == null");
        }
        String arg = (username == null ? "" : username) + (groupname == null ? "" : ":" + groupname);
        String[] cmd = Shell.getSetOwnerCommand(arg);
        execCommand(file, cmd);
    }

    /**
     * Platform independent implementation for {@link File#setReadable(boolean)} File#setReadable does not work as
     * expected on Windows.
     *
     * @param f        input file
     * @param readable
     *
     * @return true on success, false otherwise
     */
    public static boolean setReadable(File f, boolean readable) {
        if (Shell.WINDOWS) {
            try {
                String permission = readable ? "u+r" : "u-r";
                FileUtil.chmod(f.getCanonicalPath(), permission, false);
                return true;
            } catch (IOException ex) {
                return false;
            }
        } else {
            return f.setReadable(readable);
        }
    }

    /**
     * Platform independent implementation for {@link File#setWritable(boolean)} File#setWritable does not work as
     * expected on Windows.
     *
     * @param f        input file
     * @param writable
     *
     * @return true on success, false otherwise
     */
    public static boolean setWritable(File f, boolean writable) {
        if (Shell.WINDOWS) {
            try {
                String permission = writable ? "u+w" : "u-w";
                FileUtil.chmod(f.getCanonicalPath(), permission, false);
                return true;
            } catch (IOException ex) {
                return false;
            }
        } else {
            return f.setWritable(writable);
        }
    }

    /**
     * Platform independent implementation for {@link File#setExecutable(boolean)} File#setExecutable does not work as
     * expected on Windows. Note: revoking execute permission on folders does not have the same behavior on Windows as
     * on Unix platforms. Creating, deleting or renaming a file within that folder will still succeed on Windows.
     *
     * @param f          input file
     * @param executable
     *
     * @return true on success, false otherwise
     */
    public static boolean setExecutable(File f, boolean executable) {
        if (Shell.WINDOWS) {
            try {
                String permission = executable ? "u+x" : "u-x";
                FileUtil.chmod(f.getCanonicalPath(), permission, false);
                return true;
            } catch (IOException ex) {
                return false;
            }
        } else {
            return f.setExecutable(executable);
        }
    }

    /**
     * Platform independent implementation for {@link File#canRead()}
     *
     * @param f input file
     *
     * @return On Unix, same as {@link File#canRead()} On Windows, true if process has read access on the path
     */
    public static boolean canRead(File f) {
        if (Shell.WINDOWS) {
            try {
                return NativeIO.Windows.access(f.getCanonicalPath(), NativeIO.Windows.AccessRight.ACCESS_READ);
            } catch (IOException e) {
                return false;
            }
        } else {
            return f.canRead();
        }
    }

    /**
     * Platform independent implementation for {@link File#canWrite()}
     *
     * @param f input file
     *
     * @return On Unix, same as {@link File#canWrite()} On Windows, true if process has write access on the path
     */
    public static boolean canWrite(File f) {
        if (Shell.WINDOWS) {
            try {
                return NativeIO.Windows.access(f.getCanonicalPath(), NativeIO.Windows.AccessRight.ACCESS_WRITE);
            } catch (IOException e) {
                return false;
            }
        } else {
            return f.canWrite();
        }
    }

    /**
     * Platform independent implementation for {@link File#canExecute()}
     *
     * @param f input file
     *
     * @return On Unix, same as {@link File#canExecute()} On Windows, true if process has execute access on the path
     */
    public static boolean canExecute(File f) {
        if (Shell.WINDOWS) {
            try {
                return NativeIO.Windows.access(f.getCanonicalPath(), NativeIO.Windows.AccessRight.ACCESS_EXECUTE);
            } catch (IOException e) {
                return false;
            }
        } else {
            return f.canExecute();
        }
    }

    /**
     * Set permissions to the required value. Uses the java primitives instead of forking if group == other.
     *
     * @param f          the file to change
     * @param permission the new permissions
     *
     * @throws IOException
     */
    public static void setPermission(File f, FsPermission permission) throws IOException {
        FsAction user = permission.getUserAction();
        FsAction group = permission.getGroupAction();
        FsAction other = permission.getOtherAction();

        // use the native/fork if the group/other permissions are different
        // or if the native is available or on Windows
        if (group != other || NativeIO.isAvailable() || Shell.WINDOWS) {
            execSetPermission(f, permission);
            return;
        }

        boolean rv = true;

        // read perms
        rv = f.setReadable(group.implies(FsAction.READ), false);
        checkReturnValue(rv, f, permission);
        if (group.implies(FsAction.READ) != user.implies(FsAction.READ)) {
            rv = f.setReadable(user.implies(FsAction.READ), true);
            checkReturnValue(rv, f, permission);
        }

        // write perms
        rv = f.setWritable(group.implies(FsAction.WRITE), false);
        checkReturnValue(rv, f, permission);
        if (group.implies(FsAction.WRITE) != user.implies(FsAction.WRITE)) {
            rv = f.setWritable(user.implies(FsAction.WRITE), true);
            checkReturnValue(rv, f, permission);
        }

        // exec perms
        rv = f.setExecutable(group.implies(FsAction.EXECUTE), false);
        checkReturnValue(rv, f, permission);
        if (group.implies(FsAction.EXECUTE) != user.implies(FsAction.EXECUTE)) {
            rv = f.setExecutable(user.implies(FsAction.EXECUTE), true);
            checkReturnValue(rv, f, permission);
        }
    }

    private static void checkReturnValue(boolean rv, File p, FsPermission permission) throws IOException {
        if (!rv) {
            throw new IOException("Failed to set permissions of path: " + p + " to "
                    + String.format("%04o", permission.toShort()));
        }
    }

    private static void execSetPermission(File f, FsPermission permission) throws IOException {
        if (NativeIO.isAvailable()) {
            NativeIO.POSIX.chmod(f.getCanonicalPath(), permission.toShort());
        } else {
            execCommand(f, Shell.getSetPermissionCommand(String.format("%04o", permission.toShort()), false));
        }
    }

    public static String execCommand(File f, String... cmd) throws IOException {
        String[] args = new String[cmd.length + 1];
        System.arraycopy(cmd, 0, args, 0, cmd.length);
        args[cmd.length] = f.getCanonicalPath();
        String output = Shell.execCommand(args);
        return output;
    }

    /**
     * Create a tmp file for a base file.
     *
     * @param basefile       the base file of the tmp
     * @param prefix         file name prefix of tmp
     * @param isDeleteOnExit if true, the tmp will be deleted when the VM exits
     *
     * @return a newly created tmp file
     *
     * @throws IOException If a tmp file cannot created
     * @see File#createTempFile(String, String, File)
     * @see File#deleteOnExit()
     */
    public static final File createLocalTempFile(final File basefile, final String prefix,
            final boolean isDeleteOnExit) throws IOException {
        File tmp = File.createTempFile(prefix + basefile.getName(), "", basefile.getParentFile());
        if (isDeleteOnExit) {
            tmp.deleteOnExit();
        }
        return tmp;
    }

    /**
     * Move the src file to the name specified by target.
     *
     * @param src    the source file
     * @param target the target file
     *
     * @throws IOException If this operation fails
     */
    public static void replaceFile(File src, File target) throws IOException {
        /* renameTo() has two limitations on Windows platform.
         * src.renameTo(target) fails if
         * 1) If target already exists OR
         * 2) If target is already open for reading/writing.
         */
        if (!src.renameTo(target)) {
            int retries = 5;
            while (target.exists() && !target.delete() && retries-- >= 0) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    throw new IOException("replaceFile interrupted.");
                }
            }
            if (!src.renameTo(target)) {
                throw new IOException("Unable to rename " + src + " to " + target);
            }
        }
    }

    /**
     * A wrapper for {@link File#listFiles()}. This java.io API returns null when a dir is not a directory or for any
     * I/O error. Instead of having null check everywhere File#listFiles() is used, we will add utility API to get
     * around this problem. For the majority of cases where we prefer an IOException to be thrown.
     *
     * @param dir directory for which listing should be performed
     *
     * @return list of files or empty list
     *
     * @throws IOException for invalid directory or for a bad disk.
     */
    public static File[] listFiles(File dir) throws IOException {
        File[] files = dir.listFiles();
        if (files == null) {
            throw new IOException("Invalid directory or I/O error occurred for dir: " + dir.toString());
        }
        return files;
    }

    /**
     * A wrapper for {@link File#list()}. This java.io API returns null when a dir is not a directory or for any I/O
     * error. Instead of having null check everywhere File#list() is used, we will add utility API to get around this
     * problem. For the majority of cases where we prefer an IOException to be thrown.
     *
     * @param dir directory for which listing should be performed
     *
     * @return list of file names or empty string list
     *
     * @throws IOException for invalid directory or for a bad disk.
     */
    public static String[] list(File dir) throws IOException {
        String[] fileNames = dir.list();
        if (fileNames == null) {
            throw new IOException("Invalid directory or I/O error occurred for dir: " + dir.toString());
        }
        return fileNames;
    }

    public static String[] createJarWithClassPath(String inputClassPath, Path pwd, Map<String, String> callerEnv)
            throws IOException {
        return createJarWithClassPath(inputClassPath, pwd, pwd, callerEnv);
    }

    /**
     * Create a jar file at the given path, containing a manifest with a classpath that references all specified
     * entries.
     * <p>
     * Some platforms may have an upper limit on command line length.  For example, the maximum command line length on
     * Windows is 8191 characters, but the length of the classpath may exceed this.  To work around this limitation, use
     * this method to create a small intermediate jar with a manifest that contains the full classpath.  It returns the
     * absolute path to the new jar, which the caller may set as the classpath for a new process.
     * <p>
     * Environment variable evaluation is not supported within a jar manifest, so this method expands environment
     * variables before inserting classpath entries to the manifest.  The method parses environment variables according
     * to platform-specific syntax (%VAR% on Windows, or $VAR otherwise).  On Windows, environment variables are
     * case-insensitive.  For example, %VAR% and %var% evaluate to the same value.
     * <p>
     * Specifying the classpath in a jar manifest does not support wildcards, so this method expands wildcards
     * internally.  Any classpath entry that ends with * is translated to all files at that path with extension .jar or
     * .JAR.
     *
     * @param inputClassPath String input classpath to bundle into the jar manifest
     * @param pwd            Path to working directory to save jar
     * @param targetDir      path to where the jar execution will have its working dir
     * @param callerEnv      Map<String, String> caller's environment variables to use for expansion
     *
     * @return String[] with absolute path to new jar in position 0 and unexpanded wild card entry path in position 1
     *
     * @throws IOException if there is an I/O error while writing the jar file
     */
    public static String[] createJarWithClassPath(String inputClassPath, Path pwd, Path targetDir,
            Map<String, String> callerEnv) throws IOException {
        // Replace environment variables, case-insensitive on Windows
        @SuppressWarnings("unchecked")
        Map<String, String> env = Shell.WINDOWS ? new CaseInsensitiveMap(callerEnv) : callerEnv;
        String[] classPathEntries = inputClassPath.split(File.pathSeparator);
        for (int i = 0; i < classPathEntries.length; ++i) {
            classPathEntries[i] = StringUtils.replaceTokens(classPathEntries[i], StringUtils.ENV_VAR_PATTERN, env);
        }
        File workingDir = new File(pwd.toString());
        if (!workingDir.mkdirs()) {
            // If mkdirs returns false because the working directory already exists,
            // then this is acceptable.  If it returns false due to some other I/O
            // error, then this method will fail later with an IOException while saving
            // the jar.
            LOG.debug("mkdirs false for " + workingDir + ", execution will continue");
        }

        StringBuilder unexpandedWildcardClasspath = new StringBuilder();
        // Append all entries
        List<String> classPathEntryList = new ArrayList<String>(classPathEntries.length);
        for (String classPathEntry : classPathEntries) {
            if (classPathEntry.length() == 0) {
                continue;
            }
            if (classPathEntry.endsWith("*")) {
                boolean foundWildCardJar = false;
                // Append all jars that match the wildcard
                Path globPath = new Path(classPathEntry).suffix("{.jar,.JAR}");
                FileStatus[] wildcardJars = FileContext.getLocalFSFileContext().util().globStatus(globPath);
                if (wildcardJars != null) {
                    for (FileStatus wildcardJar : wildcardJars) {
                        foundWildCardJar = true;
                        classPathEntryList.add(wildcardJar.getPath().toUri().toURL().toExternalForm());
                    }
                }
                if (!foundWildCardJar) {
                    unexpandedWildcardClasspath.append(File.pathSeparator);
                    unexpandedWildcardClasspath.append(classPathEntry);
                }
            } else {
                // Append just this entry
                File fileCpEntry = null;
                if (!new Path(classPathEntry).isAbsolute()) {
                    fileCpEntry = new File(targetDir.toString(), classPathEntry);
                } else {
                    fileCpEntry = new File(classPathEntry);
                }
                String classPathEntryUrl = fileCpEntry.toURI().toURL().toExternalForm();

                // File.toURI only appends trailing '/' if it can determine that it is a
                // directory that already exists.  (See JavaDocs.)  If this entry had a
                // trailing '/' specified by the caller, then guarantee that the
                // classpath entry in the manifest has a trailing '/', and thus refers to
                // a directory instead of a file.  This can happen if the caller is
                // creating a classpath jar referencing a directory that hasn't been
                // created yet, but will definitely be created before running.
                if (classPathEntry.endsWith(Path.SEPARATOR) && !classPathEntryUrl.endsWith(Path.SEPARATOR)) {
                    classPathEntryUrl = classPathEntryUrl + Path.SEPARATOR;
                }
                classPathEntryList.add(classPathEntryUrl);
            }
        }
        String jarClassPath = StringUtils.join(" ", classPathEntryList);

        // Create the manifest
        Manifest jarManifest = new Manifest();
        jarManifest.getMainAttributes().putValue(Attributes.Name.MANIFEST_VERSION.toString(), "1.0");
        jarManifest.getMainAttributes().putValue(Attributes.Name.CLASS_PATH.toString(), jarClassPath);

        // Write the manifest to output JAR file
        File classPathJar = File.createTempFile("classpath-", ".jar", workingDir);
        FileOutputStream fos = null;
        BufferedOutputStream bos = null;
        JarOutputStream jos = null;
        try {
            fos = new FileOutputStream(classPathJar);
            bos = new BufferedOutputStream(fos);
            jos = new JarOutputStream(bos, jarManifest);
        } finally {
            IOUtils.cleanup(LOG, jos, bos, fos);
        }
        String[] jarCp = { classPathJar.getCanonicalPath(), unexpandedWildcardClasspath.toString() };
        return jarCp;
    }
}