/*
* 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.tools.ant.taskdefs.optional.ssh;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.util.TeeOutputStream;
import org.apache.tools.ant.util.KeepAliveOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.StringReader;
import com.jcraft.jsch.ChannelExec;
import com.jcraft.jsch.JSchException;
import com.jcraft.jsch.Session;
/**
* Executes a command on a remote machine via ssh.
* @since Ant 1.6 (created February 2, 2003)
*/
public class SSHExec extends SSHBase {
/** the command to execute via ssh */
private String command = null;
/** units are milliseconds, default is 0=infinite */
private long maxwait = 0;
/** for waiting for the command to finish */
private Thread thread = null;
private String outputProperty = null; // like <exec>
private File outputFile = null; // like <exec>
private boolean append = false; // like <exec>
private static final String TIMEOUT_MESSAGE =
"Timeout period exceeded, connection dropped.";
/**
* Constructor for SSHExecTask.
*/
public SSHExec() {
super();
}
/**
* Sets the command to execute on the remote host.
*
* @param command The new command value
*/
public void setCommand(String command) {
this.command = command;
}
/**
* The connection can be dropped after a specified number of
* milliseconds. This is sometimes useful when a connection may be
* flaky. Default is 0, which means "wait forever".
*
* @param timeout The new timeout value in seconds
*/
public void setTimeout(long timeout) {
maxwait = timeout;
}
/**
* If used, stores the output of the command to the given file.
*
* @param output The file to write to.
*/
public void setOutput(File output) {
outputFile = output;
}
/**
* Determines if the output is appended to the file given in
* <code>setOutput</code>. Default is false, that is, overwrite
* the file.
*
* @param append True to append to an existing file, false to overwrite.
*/
public void setAppend(boolean append) {
this.append = append;
}
/**
* If set, the output of the command will be stored in the given property.
*
* @param property The name of the property in which the command output
* will be stored.
*/
public void setOutputproperty(String property) {
outputProperty = property;
}
/**
* Execute the command on the remote host.
*
* @exception BuildException Most likely a network error or bad parameter.
*/
public void execute() throws BuildException {
if (getHost() == null) {
throw new BuildException("Host is required.");
}
if (getUserInfo().getName() == null) {
throw new BuildException("Username is required.");
}
if (getUserInfo().getKeyfile() == null
&& getUserInfo().getPassword() == null) {
throw new BuildException("Password or Keyfile is required.");
}
if (command == null) {
throw new BuildException("Command is required.");
}
ByteArrayOutputStream out = new ByteArrayOutputStream();
TeeOutputStream tee = new TeeOutputStream(out, new KeepAliveOutputStream(System.out));
Session session = null;
try {
// execute the command
session = openSession();
session.setTimeout((int) maxwait);
final ChannelExec channel = (ChannelExec) session.openChannel("exec");
channel.setCommand(command);
channel.setOutputStream(tee);
channel.setExtOutputStream(tee);
channel.connect();
// wait for it to finish
thread =
new Thread() {
public void run() {
while (!channel.isEOF()) {
if (thread == null) {
return;
}
try {
sleep(500);
} catch (Exception e) {
// ignored
}
}
}
};
thread.start();
thread.join(maxwait);
if (thread.isAlive()) {
// ran out of time
thread = null;
if (getFailonerror()) {
throw new BuildException(TIMEOUT_MESSAGE);
} else {
log(TIMEOUT_MESSAGE, Project.MSG_ERR);
}
} else {
// completed successfully
if (outputProperty != null) {
getProject().setProperty(outputProperty, out.toString());
}
if (outputFile != null) {
writeToFile(out.toString(), append, outputFile);
}
// this is the wrong test if the remote OS is OpenVMS,
// but there doesn't seem to be a way to detect it.
int ec = channel.getExitStatus();
if (ec != 0) {
String msg = "Remote command failed with exit status " + ec;
if (getFailonerror()) {
throw new BuildException(msg);
} else {
log(msg, Project.MSG_ERR);
}
}
}
} catch (BuildException e) {
throw e;
} catch (JSchException e) {
if (e.getMessage().indexOf("session is down") >= 0) {
if (getFailonerror()) {
throw new BuildException(TIMEOUT_MESSAGE, e);
} else {
log(TIMEOUT_MESSAGE, Project.MSG_ERR);
}
} else {
if (getFailonerror()) {
throw new BuildException(e);
} else {
log("Caught exception: " + e.getMessage(),
Project.MSG_ERR);
}
}
} catch (Exception e) {
if (getFailonerror()) {
throw new BuildException(e);
} else {
log("Caught exception: " + e.getMessage(), Project.MSG_ERR);
}
} finally {
if (session != null && session.isConnected()) {
session.disconnect();
}
}
}
/**
* Writes a string to a file. If destination file exists, it may be
* overwritten depending on the "append" value.
*
* @param from string to write
* @param to file to write to
* @param append if true, append to existing file, else overwrite
* @exception Exception most likely an IOException
*/
private void writeToFile(String from, boolean append, File to)
throws IOException {
FileWriter out = null;
try {
out = new FileWriter(to.getAbsolutePath(), append);
StringReader in = new StringReader(from);
char[] buffer = new char[8192];
int bytesRead;
while (true) {
bytesRead = in.read(buffer);
if (bytesRead == -1) {
break;
}
out.write(buffer, 0, bytesRead);
}
out.flush();
} finally {
if (out != null) {
out.close();
}
}
}
}
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