| /** |
| * 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 |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * 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 org.apache.hadoop.fs; |
| |
| import java.io.BufferedReader; |
| import java.io.FileNotFoundException; |
| import java.io.IOException; |
| import java.util.HashMap; |
| import java.util.Map; |
| import java.util.NoSuchElementException; |
| import java.util.StringTokenizer; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.fs.permission.FsPermission; |
| import org.apache.hadoop.util.Shell; |
| |
| import com.google.common.annotations.VisibleForTesting; |
| |
| /** |
| * Wrapper for the Unix stat(1) command. Used to workaround the lack of |
| * lstat(2) in Java 6. |
| */ |
| @InterfaceAudience.LimitedPrivate({"HDFS", "MapReduce"}) |
| @InterfaceStability.Evolving |
| public class Stat extends Shell { |
| |
| private final Path original; |
| private final Path qualified; |
| private final Path path; |
| private final long blockSize; |
| private final boolean dereference; |
| |
| private FileStatus stat; |
| |
| public Stat(Path path, long blockSize, boolean deref, FileSystem fs) |
| throws IOException { |
| super(0L, true); |
| // Original path |
| this.original = path; |
| // Qualify the original and strip out URI fragment via toUri().getPath() |
| Path stripped = new Path( |
| original.makeQualified(fs.getUri(), fs.getWorkingDirectory()) |
| .toUri().getPath()); |
| // Re-qualify the bare stripped path and store it |
| this.qualified = |
| stripped.makeQualified(fs.getUri(), fs.getWorkingDirectory()); |
| // Strip back down to a plain path |
| this.path = new Path(qualified.toUri().getPath()); |
| this.blockSize = blockSize; |
| this.dereference = deref; |
| // LANG = C setting |
| Map<String, String> env = new HashMap<String, String>(); |
| env.put("LANG", "C"); |
| setEnvironment(env); |
| } |
| |
| public FileStatus getFileStatus() throws IOException { |
| run(); |
| return stat; |
| } |
| |
| /** |
| * Whether Stat is supported on the current platform |
| * @return |
| */ |
| public static boolean isAvailable() { |
| if (Shell.LINUX || Shell.FREEBSD || Shell.MAC) { |
| return true; |
| } |
| return false; |
| } |
| |
| @VisibleForTesting |
| FileStatus getFileStatusForTesting() { |
| return stat; |
| } |
| |
| @Override |
| protected String[] getExecString() { |
| String derefFlag = "-"; |
| if (dereference) { |
| derefFlag = "-L"; |
| } |
| if (Shell.LINUX) { |
| return new String[] { |
| "stat", derefFlag + "c", "%s,%F,%Y,%X,%a,%U,%G,%N", path.toString() }; |
| } else if (Shell.FREEBSD || Shell.MAC) { |
| return new String[] { |
| "stat", derefFlag + "f", "%z,%HT,%m,%a,%Op,%Su,%Sg,`link' -> `%Y'", |
| path.toString() }; |
| } else { |
| throw new UnsupportedOperationException( |
| "stat is not supported on this platform"); |
| } |
| } |
| |
| @Override |
| protected void parseExecResult(BufferedReader lines) throws IOException { |
| // Reset stat |
| stat = null; |
| |
| String line = lines.readLine(); |
| if (line == null) { |
| throw new IOException("Unable to stat path: " + original); |
| } |
| if (line.endsWith("No such file or directory") || |
| line.endsWith("Not a directory")) { |
| throw new FileNotFoundException("File " + original + " does not exist"); |
| } |
| if (line.endsWith("Too many levels of symbolic links")) { |
| throw new IOException("Possible cyclic loop while following symbolic" + |
| " link " + original); |
| } |
| // 6,symbolic link,6,1373584236,1373584236,lrwxrwxrwx,andrew,andrew,`link' -> `target' |
| // OR |
| // 6,symbolic link,6,1373584236,1373584236,lrwxrwxrwx,andrew,andrew,'link' -> 'target' |
| StringTokenizer tokens = new StringTokenizer(line, ","); |
| try { |
| long length = Long.parseLong(tokens.nextToken()); |
| boolean isDir = tokens.nextToken().equalsIgnoreCase("directory") ? true |
| : false; |
| // Convert from seconds to milliseconds |
| long modTime = Long.parseLong(tokens.nextToken())*1000; |
| long accessTime = Long.parseLong(tokens.nextToken())*1000; |
| String octalPerms = tokens.nextToken(); |
| // FreeBSD has extra digits beyond 4, truncate them |
| if (octalPerms.length() > 4) { |
| int len = octalPerms.length(); |
| octalPerms = octalPerms.substring(len-4, len); |
| } |
| FsPermission perms = new FsPermission(Short.parseShort(octalPerms, 8)); |
| String owner = tokens.nextToken(); |
| String group = tokens.nextToken(); |
| String symStr = tokens.nextToken(); |
| // 'notalink' |
| // `link' -> `target' OR 'link' -> 'target' |
| // '' -> '' |
| Path symlink = null; |
| String parts[] = symStr.split(" -> "); |
| try { |
| String target = parts[1]; |
| target = target.substring(1, target.length()-1); |
| if (!target.isEmpty()) { |
| symlink = new Path(target); |
| } |
| } catch (ArrayIndexOutOfBoundsException e) { |
| // null if not a symlink |
| } |
| // Set stat |
| stat = new FileStatus(length, isDir, 1, blockSize, modTime, accessTime, |
| perms, owner, group, symlink, qualified); |
| } catch (NumberFormatException e) { |
| throw new IOException("Unexpected stat output: " + line, e); |
| } catch (NoSuchElementException e) { |
| throw new IOException("Unexpected stat output: " + line, e); |
| } |
| } |
| } |