System Programming





Kernel and system programming is the process of creating the software necessary for a computer or device to function and operate other programs. Some operating systems (such as Microsoft Windows) are proprietary, but others, such as the various Linux distributions, are open source.

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while executing spring boot soap example keep getting error like below


The Tomcat connector configured to listen on port 8081 failed to start. The port may already be in use or the connector may be misconfigured.


Verify the connector's configuration, identify and stop any process that's listening on port 8081, or configure this application to listen on another port.

I tried 8080 as well in even that did not work

how to find what ports are free on my windows 10 laptop to use that ?

please advise
what are differences between project explorer and package explorer in eclipse.

how to open package explorer by default when opening eclipse

Please advise
Are SOAP web services are state-full

I read REST ones are stateless

Please advise
Hi Experts,
Wondering why are my programs not always listed under start/my programs?!
I was looking for a program installed there about a month ago, and was listed there under my programs as well..
Today when I was looking for it, it was nowhere to be found!!
And I had forgotten the name of it..
Luckily I had this program installed in another pc where it was still being listed..
Once I got the name, I was able to type in and it opened.
But why all this hide and seek?!

Wonder why screen 2 approach better than screen 1 approach.
Please advise
Hi Experts,

We have the following function that used to work for years, now suddenly its starting to cause problems.

Public Sub SendEmail(Optional sTo As String = "", Optional sFrom As String = "", Optional sSubject As String = "", Optional sBody As String = "")
    Dim imsg As Object
    Dim iconf As Object
    Dim flds As Object
    Dim schema As String

    Set imsg = CreateObject("CDO.Message")
    Set iconf = CreateObject("CDO.Configuration")
    Set flds = iconf.Fields

    ' send one copy with SMTP server (with autentication)
    schema = ""
    flds.Item(schema & "sendusing") = cdoSendUsingPort
    flds.Item(schema & "smtpserver") = ""
    flds.Item(schema & "smtpserverport") = 3535
    flds.Item(schema & "smtpauthenticate") = cdoBasic

    flds.Item(schema & "sendusername") = ""
    flds.Item(schema & "sendpassword") = "MyPWD"
    flds.Item(schema & "smtpusessl") = False

    With imsg
        .To = sTo
        .From = sFrom
        .Subject = sSubject
        .HTMLBody = sBody
       '.Sender = "Sender"
        '.Organization = "My Company"
        '.ReplyTo = ""
        Set .Configuration = iconf
    End With

    Set iconf = Nothing
    Set imsg = Nothing
    Set flds = Nothing
End Sub

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See attached error message.
How to view the contents of a VMCORE file?
Similar to what Author Comment by:apunkabollywood did on ticket ID: 39512494 2013-09-21
I have a couple of VBScripts that were generated a couple of years ago as one of the options in CuteFTP Pro. The scripts connect by FTP, go to my website, then upload or delete certain files. They've worked fine with no problems every month until recently.   Now, I'm getting this error message:

Error Message That Appears When Trying to Run the Program
With a little help from an expert here on EE, I think I've narrowed down what the problem really is. I don't think the problem is with CuteFTP.  I think it is connected with some type of Microsoft system operations, and I have a feeling that an expert versed in Visual Basic can help me get the scripts running again. It looks like the problem is connected with the "Library Not Registered" notation, but that's as far as I can go on my own technically.

Here's part of one of the scripts in question:
' VBS Script Generated by CuteFTP (TM) macro recorder.
' Generated at: 4/8/2015 4:51:49 PM.
' Revised 9/1/2015
' MASTER Upload Spots Script - Oldies - Six Spots

' Create TEConnection object
Set MySite = CreateObject("CuteFTPPro.TEConnection")

' Initialize remote server host name, protocol, port, etc.
MySite.Host = "ftp.[mywebiste].com"
MySite.Protocol = "FTP"
MySite.Port = 21
MySite.Retries = 30
MySite.Delay = 30
MySite.MaxConnections = 4
MySite.TransferType = "AUTO"
MySite.DataChannel = "DEFAULT"
MySite.AutoRename = "OFF"
' WARNING!!! SENSITIVE DATA: user name and password.
MySite.Login = …
Eclipse has tabs File,Edit,Navigate,Search, Project etc at top

Under project there is Clean and 'Build All' options to clean and build 10 different projects(project_1, project_2....project_10) i have at one stroke

but after doing that i get error as below for project_10
Error:Counld not fine or load main class

if i do maven install on project _10 then above error is resolved but later stage i get

javax.naming.NoInitialContextException: Cannot instantiate class: weblogic.jndi.WLInitialContextFactory [Root exception is java.lang.ClassNotFoundException: weblogic.jndi.WLInitialContextFactory]

how maven install or maven build is different from Eclipse-->Project--->Build All
Hello Experts,
we have a HTML code like :-
[root@200]# cat

echo "</pre><br/><br/><u>MRComponents</u><br/><br/>"
echo "<table border=1 style='font-family:Calibri;font-size:11px'><tr><td><b>PID</b></td><td>" | awk '{print $0"<b>Application</b></td><td><b>Socket</b></td></tr>"}';
ps ax | awk '($3 ~ /[RS]/) && ($5 !~ /gnome-terminal/) && ($5 ~ /active/||/BroadCast/||/TServer/||/Broadcast/||/GOCONNECTION/||/POS/||/CM/||/CC/||/SMM/||/DoubleAgent/) && ($5 !~ /awk/) && ($5 !~ /sh/) {print "<tr><td>"$1"</td><td>"$5"</td><td>"$6"&nbsp;&nbsp;"$7"</td></tr>"}'
echo "</table><br/>";

HTML Output :-

HTML OutputHTML Output</pre><br/><br/><u>MRComponents</u><br/><br/>
<table border=1 style='font-family:Calibri;font-size:11px'><tr><td><b>PID</b></td><td><b>Application</b></td><td><b>Socket</b></td></tr>

Can someone please give me a script that allows me to robocopy a lot of directories from a source to a destination while referencing the directory names listed in a text file
The list will be in c:\scripts
checked exception

public class ThrowEx {

      public static void main(String[] args) {
            throw new Exception("file not there");
            catch(Exception e){



why i ned to have try catch for above example.

If i skip i am getting compilation error

Exception could be Run time(unchecked which does not need explicit try catch like indexoutofbound, arthematic) , unchecked(which needs explicit try catch like IOException)
as well right?

please advise
Class Parent{
Class Child extends Parent{
//override in child
processChildMethod(){//not overriden by parent method


Parent p= new Child();

Child c=(Child)p// why we do like this


my quwstion is  why we downcase like this

Child c=(Child)p

Child ch=new Child();
above is enough right?
please advisse
How to find the usage of RAM by a particular process??
Hi Experts,
How do I check which program is consuming the most memory?
See attached many columns I have to choose from..
Hi Experts,
Anyone knows of an easy way to determine the .net version running on my pc?
Would prefer a vba function..
Necesito compilar masivamente programas cobol de mi as400 versión 7.1  a versión 6.1. Existe alguna forma de compilar en forma masiva y no uno por uno?

I need to compile a lot of cobol programs from my as400 version 7.1 to version 6.1. Is there a way to compile a huge amount of cobol programs at once instead of one by one?
which approach is better as given below and why. please advise

Convert with Plain Java
Let’s start with a simple example using Java to do the conversion – using an intermediary byte array:

public void givenUsingPlainJava_whenConvertingStringToInputStream_thenCorrect()
  throws IOException {
    String initialString = "text";
    InputStream targetStream = new ByteArrayInputStream(initialString.getBytes());
Note that the getBytes() method encodes this String using the platform’s default charset so to avoid undesirable behavior you can use getBytes(Charset charset) and control the encoding process.

 Convert with Commons IO
Finally, the Apache Commons IO library provides an excellent direct solution:

public void givenUsingCommonsIO_whenConvertingStringToInputStream_thenCorrect()
  throws IOException {
    String initialString = "text";
    InputStream targetStream = IOUtils.toInputStream(initialString);
How to send a command /dev/ttyXX.

I've tried these and none seem to worK;
1. echo "stop" > ttyS1
2. echo -ne "stop\n" > ttyS1
public enum WhoisRIR {

    private String url;

    WhoisRIR(String url) {
        this.url = url;

    public String url() {
        return url;
public class Test {

    public static void main(String[] args) {




Open in new window

going through above code from below link

i was not clear how i got output as below

is enum like a class?
how enum different from java class?

when we use enum

not clear on below as well
Enum + Method + Some logic
public enum Operation {

    double calculate(double x, double y) {
        switch (this) {
            case PLUS:
                return x + y;
            case MINUS:
                return x - y;
            case TIMES:
                return x * y;
            case DIVIDE:
                return x / y;
                throw new AssertionError("Unknown operations " + this);

public class Test {

    public static void main(String[] args) {

        double result = Operation.PLUS.calculate(1, 2);
        System.out.println(result); //3.0


4. How to use Enum
4.1 To loop a Enum object.

public class Test {

    public static void main(String[] args) {

        for (UserStatus status : UserStatus.values()) {




Open in new window

please advise

The prolema that I encounter is related to classical programming.
I want to upload an image (jpeg, gif etc) into the sql server. We did not succeed with all our efforts. If you can help me, I will remain eternally grateful
All right,
how to open .mbz files
Hi Experts,

We have a third party system that generates a file in a FTP server every 15 min.
Now we would like to import this file into Caspio bridge.
Caspio bridge has the capability to add under scheduled tasks to import files from a FTP server.

However I'm facing the following issue.
Caspio bridge expects a fixed name file, while the system which generates files to the FTP server is set to add time stamp into the names of the files created.

Wondering what is the solution?
Perhaps you can help me put together some code that will rename files under that FTP site?
i have a existing junit file which basicaly using power mock and validating incoming messages to existings system say XYZ.  I see big XML there with bunch of tags as below

String message = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>>"
                              + "<Msg><uap>2013-09-2
++ "<id><udd>12

now i need to modify above xml with new xml generated using new xsd.

how to do that?

why xml represented as above with concatenation of + in between
any good ends to end example on this

please advise
any free tools like xpmspy which is free for generating sample xmls from XSDs and to work with XSLT etc.

I head XMLEdit but i did not see any direct link to download though?

Please advise

System Programming





Kernel and system programming is the process of creating the software necessary for a computer or device to function and operate other programs. Some operating systems (such as Microsoft Windows) are proprietary, but others, such as the various Linux distributions, are open source.