org.apache.hadoop.fs.permission.UmaskParser Maven / Gradle / Ivy
/**
* 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.permission;
import java.util.regex.Pattern;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
/**
* Parse umask value provided as a string, either in octal or symbolic
* format and return it as a short value. Umask values are slightly
* different from standard modes as they cannot specify sticky bit
* or X.
*
*/
@InterfaceAudience.Private
@InterfaceStability.Unstable
class UmaskParser extends PermissionParser {
private static Pattern chmodOctalPattern =
Pattern.compile("^\\s*[+]?(0*)([0-7]{3})\\s*$"); // no leading 1 for sticky bit
private static Pattern umaskSymbolicPattern = /* not allow X or t */
Pattern.compile("\\G\\s*([ugoa]*)([+=-]+)([rwx]*)([,\\s]*)\\s*");
final short umaskMode;
public UmaskParser(String modeStr) throws IllegalArgumentException {
super(modeStr, umaskSymbolicPattern, chmodOctalPattern);
umaskMode = (short)combineModes(0, false);
}
/**
* To be used for file/directory creation only. Symbolic umask is applied
* relative to file mode creation mask; the permission op characters '+'
* results in clearing the corresponding bit in the mask, '-' results in bits
* for indicated permission to be set in the mask.
*
* For octal umask, the specified bits are set in the file mode creation mask.
*
* @return umask
*/
public short getUMask() {
if (symbolic) {
// Return the complement of octal equivalent of umask that was computed
return (short) (~umaskMode & 0777);
}
return umaskMode;
}
}