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/**
* Copyright 2015 Santhosh Kumar Tekuri
*
* The JLibs authors license 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 jlibs.core.lang;
import jlibs.core.io.IOPump;
import jlibs.core.io.IOUtil;
import java.io.*;
import java.lang.ref.WeakReference;
import java.util.StringTokenizer;
/**
* The class contains Runtime related utilities
*
* @author Santhosh Kumar T
*/
public class RuntimeUtil{
/**
* Redirects given process's input and error streams to the specified streams.
* the streams specified are not closed automatically. The streams passed
* can be null, if you don't want to redirect them.
*
* @param process process whose streams to be redirected
* @param output outputStream to which process's inputStream is redirected.
* null if you don't want to redirect.
* @param error outputStream to which process's errorStream is redirected.
* null if you don't want to redirect.
*/
public static void redirectStreams(Process process, OutputStream output, OutputStream error){
if(output!=null)
new Thread(new IOPump(process.getInputStream(), output, false, false).asRunnable()).start();
if(error!=null)
new Thread(new IOPump(process.getErrorStream(), error, false, false).asRunnable()).start();
}
/*-------------------------------------------------[ Terminal Command ]---------------------------------------------------*/
/**
* Runs the specified command in terminal (sh in *nix/cmd in windows) and
* returns the command output.
*
* @param command complete command to be executed
* @param envp array of strings, each element of which
* has environment variable settings in the format
* name=value, or
* null if the subprocess should inherit
* the environment of the current process.
*
* @param workingDir the working directory of the subprocess, or
* null if the subprocess should inherit
* the working directory of the current process.
*
* @return output of the command.
*
* @throws IOException If an I/O error occurs
*
* @see #runCommand(String)
*/
public static String runCommand(String command, String[] envp, File workingDir) throws IOException{
String cmd[];
if(OS.get().isUnix())
cmd = new String[]{ "sh", "-c", command };
else
cmd = new String[]{ "cmd", "/C", command };
Process p = Runtime.getRuntime().exec(cmd, envp, workingDir);
ByteArrayOutputStream output = new ByteArrayOutputStream();
redirectStreams(p, output, System.err);
try{
p.waitFor();
}catch(InterruptedException ex){
throw new RuntimeException("interrupted", ex);
}
if(p.exitValue()!=0)
throw new IOException("exitValue is "+p.exitValue());
return output.toString();
}
/**
* Runs the specified command in terminal (sh in *nix/cmd in windows) and
* returns the command output. The subprocess created inherits environment and working
* directory from the current process
*
* @param command complete command to be executed
* @return output of the command.
*
* @throws IOException If an I/O error occurs
*
* @see #runCommand(String, String[], java.io.File)
*/
public static String runCommand(String command) throws IOException{
return runCommand(command, null, null);
}
/*-------------------------------------------------[ PID ]---------------------------------------------------*/
/**
* Returns the PID of the current process. The PID will also be saved in system property "pid"
*
* @return PID of current progress
*
* @throws IOException If an I/O error occurs
*/
public static String getPID() throws IOException{
String pid = System.getProperty("pid"); //NOI18N
if(pid==null){
String command;
if(OS.get().isUnix())
command = "echo $$ $PPID";
else{
// getpids.exe is taken from http://www.scheibli.com/projects/getpids/index.html (GPL)
File tempFile = File.createTempFile("getpids", "exe"); //NOI18N
// extract the embedded getpids.exe file from the jar and save it to above file
IOUtil.pump(RuntimeUtil.class.getResourceAsStream("getpids.exe"), new FileOutputStream(tempFile), true, true); //NOI18N
command = tempFile.getAbsolutePath();
tempFile.deleteOnExit();
}
StringTokenizer stok = new StringTokenizer(runCommand(command));
stok.nextToken(); // this is pid of the process we spanned
pid = stok.nextToken();
System.setProperty("pid", pid); //NOI18N
}
return pid;
}
/*-------------------------------------------------[ Garbage Collection ]---------------------------------------------------*/
/**
* This method guarantees that garbage collection is
* done unlike {@link System#gc()}
*/
public static void gc(){
Object obj = new Object();
WeakReference ref = new WeakReference