/*
* 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;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.lang.reflect.Method;
import java.util.LinkedList;
import java.util.List;
import jline.Terminal;
import org.apache.felix.gogo.commands.Command;
import org.apache.felix.gogo.commands.Option;
import org.apache.karaf.shell.console.AbstractAction;
@Command(scope = "shell", name = "more", description = "File pager.")
public class MoreAction extends AbstractAction {
@Option(name = "--lines", description = "stop after N lines")
int lines;
@Override
protected Object doExecute() throws Exception {
Terminal term = (Terminal) session.get(".jline.terminal");
if (term == null || !isTty(System.out)) {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
return null;
} else {
boolean echo = term.isEchoEnabled();
term.setEchoEnabled(false);
try {
if (lines == 0) {
lines = term.getHeight();
}
LineSplitter reader = new LineSplitter(new BufferedReader(new InputStreamReader(System.in)), term.getWidth());
int count = 0;
int c;
do {
do {
String line;
if ((line = reader.readLine()) == null) {
return null;
}
System.out.println(line);
} while (++count < lines - 2);
c = -1;
while (c == -1) {
System.out.flush();
System.out.print("--More--");
System.out.flush();
c = term.readVirtualKey(session.getKeyboard());
switch (c) {
case 'q':
case -1:
c = 'q';
break;
case '\r':
case '\n':
case 14: // Down arrow
count--;
System.out.print("\r \r");
break;
case ' ':
count = 0;
System.out.print("\r \r");
break;
case 16: // Up arrow
// fall through
default:
c = -1;
System.out.print("\r \r");
break;
}
if (c == 'q') {
break;
}
}
} while (c != 'q');
return null;
} finally {
term.setEchoEnabled(echo);
}
}
}
public static class LineSplitter {
private final BufferedReader reader;
private final int width;
private final List<String> lines = new LinkedList<String>();
public LineSplitter(BufferedReader reader, int width) {
this.reader = reader;
this.width = width;
}
public String readLine() throws IOException {
if (lines.isEmpty()) {
String str = reader.readLine();
if (str == null) {
return null;
}
while (str.length() > width) {
lines.add(str.substring(0, width));
str = str.substring(width);
}
lines.add(str);
}
return lines.remove(0);
}
}
protected boolean isTty(OutputStream out) {
try {
Method mth = out.getClass().getDeclaredMethod("getCurrent");
mth.setAccessible(true);
Object current = mth.invoke(out);
return current == session.getConsole();
} catch (Throwable t) {
return false;
}
}
}