org.apache.hadoop.fs.FsShellPermissions Maven / Gradle / Ivy
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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
*
* 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.util.LinkedList;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.fs.permission.ChmodParser;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.fs.shell.CommandFactory;
import org.apache.hadoop.fs.shell.CommandFormat;
import org.apache.hadoop.fs.shell.FsCommand;
import org.apache.hadoop.fs.shell.PathData;
import org.apache.hadoop.util.Shell;
import org.slf4j.Logger;
/**
* This class is the home for file permissions related commands.
* Moved to this separate class since FsShell is getting too large.
*/
@InterfaceAudience.Private
@InterfaceStability.Unstable
public class FsShellPermissions extends FsCommand {
static final Logger LOG = FsShell.LOG;
/**
* Register the permission related commands with the factory
* @param factory the command factory
*/
public static void registerCommands(CommandFactory factory) {
factory.addClass(Chmod.class, "-chmod");
factory.addClass(Chown.class, "-chown");
factory.addClass(Chgrp.class, "-chgrp");
}
/**
* The pattern is almost as flexible as mode allowed by chmod shell command.
* The main restriction is that we recognize only rwxXt. To reduce errors we
* also enforce octal mode specifications of either 3 digits without a sticky
* bit setting or four digits with a sticky bit setting.
*/
public static class Chmod extends FsShellPermissions {
public static final String NAME = "chmod";
public static final String USAGE = "[-R] PATH...";
public static final String DESCRIPTION =
"Changes permissions of a file. " +
"This works similar to the shell's chmod command with a few exceptions.\n" +
"-R: modifies the files recursively. This is the only option" +
" currently supported.\n" +
": Mode is the same as mode used for the shell's command. " +
"The only letters recognized are 'rwxXt', e.g. +t,a+r,g-w,+rwx,o=r.\n" +
": Mode specifed in 3 or 4 digits. If 4 digits, the first " +
"may be 1 or 0 to turn the sticky bit on or off, respectively. Unlike " +
"the shell command, it is not possible to specify only part of the " +
"mode, e.g. 754 is same as u=rwx,g=rx,o=r.\n\n" +
"If none of 'augo' is specified, 'a' is assumed and unlike the " +
"shell command, no umask is applied.";
protected ChmodParser pp;
@Override
protected void processOptions(LinkedList args) throws IOException {
CommandFormat cf = new CommandFormat(2, Integer.MAX_VALUE, "R", null);
cf.parse(args);
setRecursive(cf.getOpt("R"));
String modeStr = args.removeFirst();
try {
pp = new ChmodParser(modeStr);
} catch (IllegalArgumentException iea) {
// TODO: remove "chmod : " so it's not doubled up in output, but it's
// here for backwards compatibility...
throw new IllegalArgumentException(
"chmod : mode '" + modeStr + "' does not match the expected pattern.");
}
}
@Override
protected void processPath(PathData item) throws IOException {
short newperms = pp.applyNewPermission(item.stat);
if (item.stat.getPermission().toShort() != newperms) {
try {
item.fs.setPermission(item.path, new FsPermission(newperms));
} catch (IOException e) {
LOG.debug("Error changing permissions of " + item, e);
throw new IOException(
"changing permissions of '" + item + "': " + e.getMessage());
}
}
}
}
// used by chown/chgrp
static private String allowedChars = Shell.WINDOWS ? "[-_./@a-zA-Z0-9 ]" :
"[-_./@a-zA-Z0-9]";
/**
* Used to change owner and/or group of files
*/
public static class Chown extends FsShellPermissions {
public static final String NAME = "chown";
public static final String USAGE = "[-R] [OWNER][:[GROUP]] PATH...";
public static final String DESCRIPTION =
"Changes owner and group of a file. " +
"This is similar to the shell's chown command with a few exceptions.\n" +
"-R: modifies the files recursively. This is the only option " +
"currently supported.\n\n" +
"If only the owner or group is specified, then only the owner or " +
"group is modified. " +
"The owner and group names may only consist of digits, alphabet, "+
"and any of " + allowedChars + ". The names are case sensitive.\n\n" +
"WARNING: Avoid using '.' to separate user name and group though " +
"Linux allows it. If user names have dots in them and you are " +
"using local file system, you might see surprising results since " +
"the shell command 'chown' is used for local files.";
///allows only "allowedChars" above in names for owner and group
static private final Pattern chownPattern = Pattern.compile(
"^\\s*(" + allowedChars + "+)?([:](" + allowedChars + "*))?\\s*$");
protected String owner = null;
protected String group = null;
@Override
protected void processOptions(LinkedList args) throws IOException {
CommandFormat cf = new CommandFormat(2, Integer.MAX_VALUE, "R");
cf.parse(args);
setRecursive(cf.getOpt("R"));
parseOwnerGroup(args.removeFirst());
}
/**
* Parse the first argument into an owner and group
* @param ownerStr string describing new ownership
*/
protected void parseOwnerGroup(String ownerStr) {
Matcher matcher = chownPattern.matcher(ownerStr);
if (!matcher.matches()) {
throw new IllegalArgumentException(
"'" + ownerStr + "' does not match expected pattern for [owner][:group].");
}
owner = matcher.group(1);
group = matcher.group(3);
if (group != null && group.length() == 0) {
group = null;
}
if (owner == null && group == null) {
throw new IllegalArgumentException(
"'" + ownerStr + "' does not specify owner or group.");
}
}
@Override
protected void processPath(PathData item) throws IOException {
//Should we do case insensitive match?
String newOwner = (owner == null || owner.equals(item.stat.getOwner())) ?
null : owner;
String newGroup = (group == null || group.equals(item.stat.getGroup())) ?
null : group;
if (newOwner != null || newGroup != null) {
try {
item.fs.setOwner(item.path, newOwner, newGroup);
} catch (IOException e) {
LOG.debug("Error changing ownership of " + item, e);
throw new IOException(
"changing ownership of '" + item + "': " + e.getMessage());
}
}
}
}
/**
* Used to change group of files
*/
public static class Chgrp extends Chown {
public static final String NAME = "chgrp";
public static final String USAGE = "[-R] GROUP PATH...";
public static final String DESCRIPTION =
"This is equivalent to -chown ... :GROUP ...";
static private final Pattern chgrpPattern =
Pattern.compile("^\\s*(" + allowedChars + "+)\\s*$");
@Override
protected void parseOwnerGroup(String groupStr) {
Matcher matcher = chgrpPattern.matcher(groupStr);
if (!matcher.matches()) {
throw new IllegalArgumentException(
"'" + groupStr + "' does not match expected pattern for group");
}
owner = null;
group = matcher.group(1);
}
}
}
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