org.jenkinsci.plugins.proccleaner.PsBasedUnixProcessTree.java Source code

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Here is the source code for org.jenkinsci.plugins.proccleaner.PsBasedUnixProcessTree.java

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/*
 * The MIT License
 *
 * Copyright (c) 2013 Red Hat, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package org.jenkinsci.plugins.proccleaner;

import hudson.util.IOUtils;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;
import java.util.logging.Logger;

import org.apache.commons.lang.ArrayUtils;
import org.apache.commons.lang.StringUtils;

/**
 * Author: psrna
 * Date: 8/2/13
 */
public class PsBasedUnixProcessTree extends PsBasedProcessTree {

    @Override
    public PsBasedProcessTree createProcessTreeFor(String user) throws InterruptedException, IOException {
        String[] cmd = { "ps", "-u", user, "-o", "pid,ppid,args" };
        ProcessBuilder pb = new ProcessBuilder(cmd);
        pb.redirectErrorStream(true);
        final Process proc = pb.start();
        final StringWriter writer = new StringWriter();

        try {
            IOUtils.copy(proc.getInputStream(), writer);
        } catch (IOException e) {
            LOGGER.warning("'ps' command invocation IOException occurred!");
        }

        BufferedReader reader = new BufferedReader(new StringReader(writer.toString()));
        if (proc.waitFor() != 0) {
            LOGGER.warning("'ps' command invocation " + ArrayUtils.toString(cmd) + " failed! Return code: "
                    + proc.exitValue());
            LOGGER.fine("Received output from 'ps' command invocation follows:");

            if (getLog() != null) {
                getLog().println("WARNING: 'ps' command invocation " + ArrayUtils.toString(cmd)
                        + " failed! Return code: " + proc.exitValue());
                getLog().println("DEBUG: Received output from 'ps' command invocation follows:");
            }

            String line;
            while ((line = reader.readLine()) != null) {
                LOGGER.fine(line);
                if (getLog() != null)
                    getLog().println("DEBUG: '" + line + "'");
            }
            return null;
        }

        String line = reader.readLine(); // first line should be "PID  PPID COMMAND" - skip it
        if (StringUtils.isEmpty(line)) {
            LOGGER.fine("Unrecognized output from 'ps' command invocation! Output is empty!");
            if (getLog() != null) {
                getLog().println("DEBUG: Unrecognized output from 'ps' command invocation! Output is empty!");
            }
            return null;

        }
        if (!line.matches("^\\s*PID\\s*PPID\\s*(COMMAND|ARGS)\\s*$")) {
            LOGGER.fine("Unrecognized first output line from 'ps' command invocation! Was: '" + line + "'");
            if (getLog() != null) {
                getLog().println(
                        "DEBUG: Unrecognized first output line from 'ps' command invocation! Was: '" + line + "'");
            }
            return null;
        }

        PsBasedProcessTree ptree = new PsBasedUnixProcessTree();
        while ((line = reader.readLine()) != null) {
            if (getLog() != null)
                getLog().println("DEBUG: '" + line + "'");
            ptree.addProcess(line);
        }
        ptree.setLog(getLog());
        return ptree;
    }

    private static final Logger LOGGER = Logger.getLogger(PsBasedUnixProcessTree.class.getName());

}