| /** |
| * 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.IOException; |
| import java.io.PrintStream; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.LinkedList; |
| |
| import org.apache.commons.lang.WordUtils; |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.conf.Configured; |
| import org.apache.hadoop.fs.shell.Command; |
| import org.apache.hadoop.fs.shell.CommandFactory; |
| import org.apache.hadoop.fs.shell.FsCommand; |
| import org.apache.hadoop.tools.TableListing; |
| import org.apache.hadoop.util.Tool; |
| import org.apache.hadoop.util.ToolRunner; |
| |
| /** Provide command line access to a FileSystem. */ |
| @InterfaceAudience.Private |
| public class FsShell extends Configured implements Tool { |
| |
| static final Log LOG = LogFactory.getLog(FsShell.class); |
| |
| private static final int MAX_LINE_WIDTH = 80; |
| |
| private FileSystem fs; |
| private Trash trash; |
| protected CommandFactory commandFactory; |
| |
| private final String usagePrefix = |
| "Usage: hadoop fs [generic options]"; |
| |
| /** |
| * Default ctor with no configuration. Be sure to invoke |
| * {@link #setConf(Configuration)} with a valid configuration prior |
| * to running commands. |
| */ |
| public FsShell() { |
| this(null); |
| } |
| |
| /** |
| * Construct a FsShell with the given configuration. Commands can be |
| * executed via {@link #run(String[])} |
| * @param conf the hadoop configuration |
| */ |
| public FsShell(Configuration conf) { |
| super(conf); |
| } |
| |
| protected FileSystem getFS() throws IOException { |
| if (fs == null) { |
| fs = FileSystem.get(getConf()); |
| } |
| return fs; |
| } |
| |
| protected Trash getTrash() throws IOException { |
| if (this.trash == null) { |
| this.trash = new Trash(getConf()); |
| } |
| return this.trash; |
| } |
| |
| protected void init() throws IOException { |
| getConf().setQuietMode(true); |
| if (commandFactory == null) { |
| commandFactory = new CommandFactory(getConf()); |
| commandFactory.addObject(new Help(), "-help"); |
| commandFactory.addObject(new Usage(), "-usage"); |
| registerCommands(commandFactory); |
| } |
| } |
| |
| protected void registerCommands(CommandFactory factory) { |
| // TODO: DFSAdmin subclasses FsShell so need to protect the command |
| // registration. This class should morph into a base class for |
| // commands, and then this method can be abstract |
| if (this.getClass().equals(FsShell.class)) { |
| factory.registerCommands(FsCommand.class); |
| } |
| } |
| |
| /** |
| * Returns the Trash object associated with this shell. |
| * @return Path to the trash |
| * @throws IOException upon error |
| */ |
| public Path getCurrentTrashDir() throws IOException { |
| return getTrash().getCurrentTrashDir(); |
| } |
| |
| // NOTE: Usage/Help are inner classes to allow access to outer methods |
| // that access commandFactory |
| |
| /** |
| * Display help for commands with their short usage and long description |
| */ |
| protected class Usage extends FsCommand { |
| public static final String NAME = "usage"; |
| public static final String USAGE = "[cmd ...]"; |
| public static final String DESCRIPTION = |
| "Displays the usage for given command or all commands if none " + |
| "is specified."; |
| |
| @Override |
| protected void processRawArguments(LinkedList<String> args) { |
| if (args.isEmpty()) { |
| printUsage(System.out); |
| } else { |
| for (String arg : args) printUsage(System.out, arg); |
| } |
| } |
| } |
| |
| /** |
| * Displays short usage of commands sans the long description |
| */ |
| protected class Help extends FsCommand { |
| public static final String NAME = "help"; |
| public static final String USAGE = "[cmd ...]"; |
| public static final String DESCRIPTION = |
| "Displays help for given command or all commands if none " + |
| "is specified."; |
| |
| @Override |
| protected void processRawArguments(LinkedList<String> args) { |
| if (args.isEmpty()) { |
| printHelp(System.out); |
| } else { |
| for (String arg : args) printHelp(System.out, arg); |
| } |
| } |
| } |
| |
| /* |
| * The following are helper methods for getInfo(). They are defined |
| * outside of the scope of the Help/Usage class because the run() method |
| * needs to invoke them too. |
| */ |
| |
| // print all usages |
| private void printUsage(PrintStream out) { |
| printInfo(out, null, false); |
| } |
| |
| // print one usage |
| private void printUsage(PrintStream out, String cmd) { |
| printInfo(out, cmd, false); |
| } |
| |
| // print all helps |
| private void printHelp(PrintStream out) { |
| printInfo(out, null, true); |
| } |
| |
| // print one help |
| private void printHelp(PrintStream out, String cmd) { |
| printInfo(out, cmd, true); |
| } |
| |
| private void printInfo(PrintStream out, String cmd, boolean showHelp) { |
| if (cmd != null) { |
| // display help or usage for one command |
| Command instance = commandFactory.getInstance("-" + cmd); |
| if (instance == null) { |
| throw new UnknownCommandException(cmd); |
| } |
| if (showHelp) { |
| printInstanceHelp(out, instance); |
| } else { |
| printInstanceUsage(out, instance); |
| } |
| } else { |
| // display help or usage for all commands |
| out.println(usagePrefix); |
| |
| // display list of short usages |
| ArrayList<Command> instances = new ArrayList<Command>(); |
| for (String name : commandFactory.getNames()) { |
| Command instance = commandFactory.getInstance(name); |
| if (!instance.isDeprecated()) { |
| out.println("\t[" + instance.getUsage() + "]"); |
| instances.add(instance); |
| } |
| } |
| // display long descriptions for each command |
| if (showHelp) { |
| for (Command instance : instances) { |
| out.println(); |
| printInstanceHelp(out, instance); |
| } |
| } |
| out.println(); |
| ToolRunner.printGenericCommandUsage(out); |
| } |
| } |
| |
| private void printInstanceUsage(PrintStream out, Command instance) { |
| out.println(usagePrefix + " " + instance.getUsage()); |
| } |
| |
| private void printInstanceHelp(PrintStream out, Command instance) { |
| out.println(instance.getUsage() + " :"); |
| TableListing listing = null; |
| final String prefix = " "; |
| for (String line : instance.getDescription().split("\n")) { |
| if (line.matches("^[ \t]*[-<].*$")) { |
| String[] segments = line.split(":"); |
| if (segments.length == 2) { |
| if (listing == null) { |
| listing = createOptionTableListing(); |
| } |
| listing.addRow(segments[0].trim(), segments[1].trim()); |
| continue; |
| } |
| } |
| |
| // Normal literal description. |
| if (listing != null) { |
| for (String listingLine : listing.toString().split("\n")) { |
| out.println(prefix + listingLine); |
| } |
| listing = null; |
| } |
| |
| for (String descLine : WordUtils.wrap( |
| line, MAX_LINE_WIDTH, "\n", true).split("\n")) { |
| out.println(prefix + descLine); |
| } |
| } |
| |
| if (listing != null) { |
| for (String listingLine : listing.toString().split("\n")) { |
| out.println(prefix + listingLine); |
| } |
| } |
| } |
| |
| // Creates a two-row table, the first row is for the command line option, |
| // the second row is for the option description. |
| private TableListing createOptionTableListing() { |
| return new TableListing.Builder().addField("").addField("", true) |
| .wrapWidth(MAX_LINE_WIDTH).build(); |
| } |
| |
| /** |
| * run |
| */ |
| @Override |
| public int run(String argv[]) throws Exception { |
| // initialize FsShell |
| init(); |
| |
| int exitCode = -1; |
| if (argv.length < 1) { |
| printUsage(System.err); |
| } else { |
| String cmd = argv[0]; |
| Command instance = null; |
| try { |
| instance = commandFactory.getInstance(cmd); |
| if (instance == null) { |
| throw new UnknownCommandException(); |
| } |
| exitCode = instance.run(Arrays.copyOfRange(argv, 1, argv.length)); |
| } catch (IllegalArgumentException e) { |
| displayError(cmd, e.getLocalizedMessage()); |
| if (instance != null) { |
| printInstanceUsage(System.err, instance); |
| } |
| } catch (Exception e) { |
| // instance.run catches IOE, so something is REALLY wrong if here |
| LOG.debug("Error", e); |
| displayError(cmd, "Fatal internal error"); |
| e.printStackTrace(System.err); |
| } |
| } |
| return exitCode; |
| } |
| |
| private void displayError(String cmd, String message) { |
| for (String line : message.split("\n")) { |
| System.err.println(cmd + ": " + line); |
| if (cmd.charAt(0) != '-') { |
| Command instance = null; |
| instance = commandFactory.getInstance("-" + cmd); |
| if (instance != null) { |
| System.err.println("Did you mean -" + cmd + "? This command " + |
| "begins with a dash."); |
| } |
| } |
| } |
| } |
| |
| /** |
| * Performs any necessary cleanup |
| * @throws IOException upon error |
| */ |
| public void close() throws IOException { |
| if (fs != null) { |
| fs.close(); |
| fs = null; |
| } |
| } |
| |
| /** |
| * main() has some simple utility methods |
| * @param argv the command and its arguments |
| * @throws Exception upon error |
| */ |
| public static void main(String argv[]) throws Exception { |
| FsShell shell = newShellInstance(); |
| Configuration conf = new Configuration(); |
| conf.setQuietMode(false); |
| shell.setConf(conf); |
| int res; |
| try { |
| res = ToolRunner.run(shell, argv); |
| } finally { |
| shell.close(); |
| } |
| System.exit(res); |
| } |
| |
| // TODO: this should be abstract in a base class |
| protected static FsShell newShellInstance() { |
| return new FsShell(); |
| } |
| |
| /** |
| * The default ctor signals that the command being executed does not exist, |
| * while other ctor signals that a specific command does not exist. The |
| * latter is used by commands that process other commands, ex. -usage/-help |
| */ |
| @SuppressWarnings("serial") |
| static class UnknownCommandException extends IllegalArgumentException { |
| private final String cmd; |
| UnknownCommandException() { this(null); } |
| UnknownCommandException(String cmd) { this.cmd = cmd; } |
| |
| @Override |
| public String getMessage() { |
| return ((cmd != null) ? "`"+cmd+"': " : "") + "Unknown command"; |
| } |
| } |
| } |