/**
* 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.hdfs.util;
import org.apache.hadoop.io.UTF8;
public class PosixUserNameChecker implements UserNameChecker {
@Override
public boolean isValidUserName(String username) {
if (username == null || username.length() == 0)
return false;
int len = username.length();
char[] carray = UTF8.getCharArray(len);
username.getChars(0, len, carray, 0);
char fc = carray[0];
if (!((fc >= 'a' && fc <= 'z') || fc == '_')) {
return false;
}
for (int i = 1; i < len; i++) {
char c = carray[i];
if (!((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || c == '-'
|| c == '_' || (c == '$' && i == len - 1))) {
return false;
}
}
return true;
}
}