/*
* 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.karaf.shell.commands.impl;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import org.apache.karaf.shell.api.action.Action;
import org.apache.karaf.shell.api.action.Argument;
import org.apache.karaf.shell.api.action.Command;
import org.apache.karaf.shell.api.action.Completion;
import org.apache.karaf.shell.api.action.Option;
import org.apache.karaf.shell.api.action.Parsing;
import org.apache.karaf.shell.api.action.lifecycle.Reference;
import org.apache.karaf.shell.api.action.lifecycle.Service;
import org.apache.karaf.shell.api.console.CommandLine;
import org.apache.karaf.shell.api.console.Completer;
import org.apache.karaf.shell.api.console.Parser;
import org.apache.karaf.shell.api.console.Session;
import org.apache.karaf.shell.api.console.SessionFactory;
import org.apache.karaf.shell.commands.impl.WatchAction.WatchParser;
import org.apache.karaf.shell.support.ShellUtil;
import org.apache.karaf.shell.support.completers.CommandsCompleter;
import org.apache.karaf.shell.support.parsing.CommandLineImpl;
import org.apache.karaf.shell.support.parsing.DefaultParser;
@Command(scope = "shell", name = "watch", description = "Watches & refreshes the output of a command")
@Parsing(WatchParser.class)
@Service
public class WatchAction implements Action {
@Option(name = "-n", aliases = {"--interval"}, description = "The interval between executions of the command in seconds", required = false, multiValued = false)
private long interval = 1;
@Option(name = "-a", aliases = {"--append"}, description = "The output should be appended but not clear the console", required = false, multiValued = false)
private boolean append = false;
@Argument(index = 0, name = "command", description = "The command to watch / refresh", required = true, multiValued = false)
@Completion(SubCommandCompleter.class)
private String arguments;
@Reference
Session session;
@Reference
SessionFactory sessionFactory;
private ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor();
@Override
public Object execute() throws Exception {
if (arguments == null || arguments.length() == 0) {
System.err.println("Argument expected");
} else {
WatchTask watchTask = new WatchTask(arguments.trim());
executorService.scheduleAtFixedRate(watchTask, 0, interval, TimeUnit.SECONDS);
try {
session.getKeyboard().read();
watchTask.abort();
} finally {
executorService.shutdownNow();
watchTask.close();
}
}
return null;
}
public class WatchTask implements Runnable {
private final String command;
Session session;
ByteArrayOutputStream byteArrayOutputStream = null;
PrintStream printStream = null;
boolean doDisplay = true;
public WatchTask(String command) {
this.command = command;
}
public void run() {
try {
byteArrayOutputStream = new ByteArrayOutputStream();
printStream = new PrintStream(byteArrayOutputStream);
session = sessionFactory.create(null, printStream, printStream, WatchAction.this.session);
String output = "";
try {
session.execute(command);
} catch (Exception e) {
ShellUtil.logException(session, e);
}
output = byteArrayOutputStream.toString();
if (doDisplay) {
if (!append) {
System.out.print("\33[2J");
System.out.print("\33[1;1H");
}
System.out.print(output);
System.out.flush();
}
byteArrayOutputStream.close();
session.close();
} catch (Exception e) {
//Ingore
}
}
public void abort() {
doDisplay = false;
}
public void close() throws IOException {
if (this.session != null) {
this.session.close();
}
if (this.byteArrayOutputStream != null) {
this.byteArrayOutputStream.close();
}
if (this.printStream != null) {
printStream.close();
}
}
}
@Service
public static class WatchParser implements Parser {
@Override
public CommandLine parse(Session session, String command, int cursor) {
int n1 = 0;
while (n1 < command.length() && Character.isWhitespace(command.charAt(n1))) {
n1++;
if (n1 == command.length()) {
throw new IllegalArgumentException();
}
}
int n2 = n1 + 1;
while (!Character.isWhitespace(command.charAt(n2))) {
n2++;
if (n2 == command.length()) {
return new CommandLineImpl(
new String[]{command.substring(n1)},
0,
cursor - n1,
cursor,
command
);
}
}
int n3 = n2 + 1;
while (n3 < command.length() && Character.isWhitespace(command.charAt(n3))) {
n3++;
if (n3 == command.length()) {
return new CommandLineImpl(
new String[]{command.substring(n1, n2), ""},
cursor >= n2 ? 1 : 0,
cursor >= n2 ? 0 : cursor - n1,
cursor,
command
);
}
}
return new CommandLineImpl(
new String[]{command.substring(n1, n2), command.substring(n3)},
cursor >= n3 ? 1 : 0,
cursor >= n3 ? cursor - n3 : cursor - n1,
cursor,
command
);
}
@Override
public String preprocess(Session session, CommandLine cmdLine) {
StringBuilder parsed = new StringBuilder();
for (int i = 0; i < cmdLine.getArguments().length; i++) {
String arg = cmdLine.getArguments()[i];
if (i > 0) {
parsed.append(" \"");
}
parsed.append(arg);
if (i > 0) {
parsed.append("\"");
}
}
return parsed.toString();
}
}
@Service
public static class SubCommandCompleter implements Completer {
@Override
public int complete(Session session, CommandLine commandLine, List<String> candidates) {
String arg = commandLine.getCursorArgument();
int pos = commandLine.getArgumentPosition();
CommandLine cmdLine = new DefaultParser().parse(session, arg, pos);
Completer completer = session.getRegistry().getService(CommandsCompleter.class);
List<String> cands = new ArrayList<>();
int res = completer.complete(session, cmdLine, cands);
for (String cand : cands) {
candidates.add(arg.substring(0, cmdLine.getBufferPosition() - cmdLine.getArgumentPosition()) + cand);
}
if (res >= 0) {
res += commandLine.getBufferPosition() - commandLine.getArgumentPosition();
}
return res;
}
}
}