@Test
public void pidCheck() throws ConfigurationException, IOException {

    Assume.assumeTrue(SystemUtils.IS_OS_LINUX);
    FileUtils.writeStringToFile(pidFile, "123456\n");
    ProcessUtil.pidCheck(pidFile.getParent(), pidFile.getName());
    String pidStr = FileUtils.readFileToString(pidFile);
    Assert.assertFalse("pid can not be blank", pidStr.isEmpty());
    int pid = Integer.parseInt(pidStr.trim());
    int maxPid = Integer.parseInt(FileUtils.readFileToString(new File("/proc/sys/kernel/pid_max")).trim());
    Assert.assertTrue(pid <= maxPid);
}