private static void usage(final String s) {
    // note that we don't document the -pids switch because it is tailored
    // to how hydra works and would not be useful for customers
    err.println(lineSeparator() + "** " + s + lineSeparator());
    err.println("Usage"
        + ": java MergeLogFiles [(directory | logFile)]+");
    err.println("-dirCount n      "
        + "Number of parent dirs to print");
    err.println("-mergeFile file  "
        + "File in which to put merged logs");
    err.println("-pids            "
        + "Search for PIDs in file names and use them to identify files");
    err.println(
        "-align           " + "Align non-timestamped lines with others");
    err.println("-noblanks        "
        + "Suppress output of blank lines");
    err.println("-threaded        "
        + "Use multithreading to take advantage of multiple CPUs");
    err.println();
    err.println(
        "Merges multiple GemFire log files and sorts them by timestamp.");
    err.println(
        "The merged log file is written to System.out (or a file).");
    err.println();
    err.println(
        "If a directory is specified, all .log files in that directory are merged.");
    err.println();
    ExitCode.FATAL.doSystemExit();
  }
Prints usage information about this program
geode-core/src/main/java/org/apache/geode/internal/logging/MergeLogFiles.java