com.taobao.arthas.common.ExecutingCommand Maven / Gradle / Ivy
package com.taobao.arthas.common;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
* A class for executing on the command line and returning the result of
* execution.
*
* @author alessandro[at]perucchi[dot]org
*/
public class ExecutingCommand {
private ExecutingCommand() {
}
/**
* Executes a command on the native command line and returns the result.
*
* @param cmdToRun
* Command to run
* @return A list of Strings representing the result of the command, or empty
* string if the command failed
*/
public static List runNative(String cmdToRun) {
String[] cmd = cmdToRun.split(" ");
return runNative(cmd);
}
/**
* Executes a command on the native command line and returns the result line by
* line.
*
* @param cmdToRunWithArgs
* Command to run and args, in an array
* @return A list of Strings representing the result of the command, or empty
* string if the command failed
*/
public static List runNative(String[] cmdToRunWithArgs) {
Process p = null;
try {
p = Runtime.getRuntime().exec(cmdToRunWithArgs);
} catch (SecurityException e) {
AnsiLog.trace("Couldn't run command {}:", Arrays.toString(cmdToRunWithArgs));
AnsiLog.trace(e);
return new ArrayList(0);
} catch (IOException e) {
AnsiLog.trace("Couldn't run command {}:", Arrays.toString(cmdToRunWithArgs));
AnsiLog.trace(e);
return new ArrayList(0);
}
ArrayList sa = new ArrayList();
BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
try {
String line;
while ((line = reader.readLine()) != null) {
sa.add(line);
}
p.waitFor();
} catch (IOException e) {
AnsiLog.trace("Problem reading output from {}:", Arrays.toString(cmdToRunWithArgs));
AnsiLog.trace(e);
return new ArrayList(0);
} catch (InterruptedException ie) {
AnsiLog.trace("Problem reading output from {}:", Arrays.toString(cmdToRunWithArgs));
AnsiLog.trace(ie);
Thread.currentThread().interrupt();
} finally {
IOUtils.close(reader);
}
return sa;
}
/**
* Return first line of response for selected command.
*
* @param cmd2launch
* String command to be launched
* @return String or empty string if command failed
*/
public static String getFirstAnswer(String cmd2launch) {
return getAnswerAt(cmd2launch, 0);
}
/**
* Return response on selected line index (0-based) after running selected
* command.
*
* @param cmd2launch
* String command to be launched
* @param answerIdx
* int index of line in response of the command
* @return String whole line in response or empty string if invalid index or
* running of command fails
*/
public static String getAnswerAt(String cmd2launch, int answerIdx) {
List sa = ExecutingCommand.runNative(cmd2launch);
if (answerIdx >= 0 && answerIdx < sa.size()) {
return sa.get(answerIdx);
}
return "";
}
}