/**
* 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.streaming;
import java.io.*;
import java.util.Date;
/** A minimal Java implementation of /usr/bin/uniq
Used to test the usage of external applications without adding
platform-specific dependencies.
Uniques lines and prepends a header on the line.
*/
public class UniqApp
{
public UniqApp(String header)
{
this.header = header;
}
public void go() throws IOException
{
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
String line;
String prevLine = null;
while ((line = in.readLine()) != null) {
if (!line.equals(prevLine)) {
System.out.println(header + line);
}
prevLine = line;
}
}
public static void main(String[] args) throws IOException
{
String h = (args.length < 1) ? "" : args[0];
UniqApp app = new UniqApp(h);
app.go();
}
String header;
}