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Create a directly-executable cross-platform GUI app using Python

You can use appJar for basic GUI development.

from appJar import gui


def myfcn(btnName):   
    global num
    num +=1
    win.setLabel("mylabel", num)

win = gui('Test')

win.addButtons(["Set"],  [myfcn])
win.addLabel("mylabel", "Press the Button")


GUI when running

See documentation at appJar site.

Installation is made with pip install appjar from command line.

Text Editor For Linux (Besides Vi)?

If it's just you? Use what you want to use today; switch in mid-stream if you want.

Is it a team? Try to be editor-agnostic. Set standards for white-space (are tabs allowed? How many spaces does a tab represent?), but otherwise allow anyone to use whichever editor they want.

Is it a team doing pair-programming? That's where you may need a team-standard editor, just so that programmers can easily pass the keyboard.

To help implement a standard white-space policy in a shop where one or more coders is using Emacs: You can tell Emacs about your white-space policy with some comments stuck at the bottom of every file source file. For example,

# Local Variables:
# tab-width: 2
# ruby-indent-level: 2
# indent-tabs-mode: nil
# End:

Anyone using emacs (or xemacs) on that file will automatically get the group standard indentation.

Options for HTML scraping?


It's basically jQuery for C#. It depends on HTML Agility Pack for parsing the HTML.

How do you format an unsigned long long int using printf?

Non-standard things are always strange :)

for the long long portion under GNU it's L, ll or q

and under windows I believe it's ll only

Recommended add-ons/plugins for Microsoft Visual Studio

XPathmania is a good little tool for writing and testing XPath queries.

How do I split a string so I can access item x?

You can leverage a Number table to do the string parsing.

Create a physical numbers table:

    create table dbo.Numbers (N int primary key);
    insert into dbo.Numbers
        select top 1000 row_number() over(order by number) from master..spt_values

Create test table with 1000000 rows

    create table #yak (i int identity(1,1) primary key, array varchar(50))

    insert into #yak(array)
        select 'a,b,c' from dbo.Numbers n cross join dbo.Numbers nn

Create the function

    create function [dbo].[ufn_ParseArray]
        (   @Input      nvarchar(4000), 
            @Delimiter  char(1) = ',',
            @BaseIdent  int
    returns table as
        (   select  row_number() over (order by n asc) + (@BaseIdent - 1) [i],
                    substring(@Input, n, charindex(@Delimiter, @Input + @Delimiter, n) - n) s
            from    dbo.Numbers
            where   n <= convert(int, len(@Input)) and
                    substring(@Delimiter + @Input, n, 1) = @Delimiter

Usage (outputs 3mil rows in 40s on my laptop)

    select * 
    from #yak 
    cross apply dbo.ufn_ParseArray(array, ',', 1)


    drop table dbo.Numbers;
    drop function  [dbo].[ufn_ParseArray]

Performance here is not amazing, but calling a function over a million row table is not the best idea. If performing a string split over many rows I would avoid the function.

How do you disable browser Autocomplete on web form field / input tag?

You can use autocomplete = off in input controls to avoid auto completion

For example:

<input type=text name="test" autocomplete="off" />

if the above code doesn't works then try to add those attributes also

autocapitalize="off" autocomplete="off"


Change input type attribute to type="search". Google doesn't apply auto-fill to inputs with a type of search.

.NET obfuscation tools/strategy

The short answer is that you can't.

There are various tools around that will make it harder for someone to read your code - some of which have been pointed out by other answers.

However, all these do is make it harder to read - they increase the amount of effort required, that is all. Often this is enough to deter casual readers, but someone who is determined to dig into your code will always be able to do so.

Auto Generate Database Diagram MySQL

phpMyAdmin has what you are looking for (for many years now): It takes a small bit of configuration, but gives you additional benefits too:

How can I remove duplicate rows?

To Fetch Duplicate Rows:

name, email, COUNT(*)
name, email

To Delete the Duplicate Rows:

DELETE users 
(SELECT MIN(rowid)
FROM users
GROUP BY name, email);      

How to find keys of a hash?

This is the best you can do, as far as I know...

var keys = [];
for (var k in h)keys.push(k);

Random integer in VB.NET

You should create a pseudo-random number generator only once:

Dim Generator As System.Random = New System.Random()

Then, if an integer suffices for your needs, you can use:

Public Function GetRandom(myGenerator As System.Random, ByVal Min As Integer, ByVal Max As Integer) As Integer
'min is inclusive, max is exclusive (dah!)
Return myGenerator.Next(Min, Max + 1)
End Function

as many times as you like. Using the wrapper function is justified only because the maximum value is exclusive - I know that the random numbers work this way but the definition of .Next is confusing.

Creating a generator every time you need a number is in my opinion wrong; the pseudo-random numbers do not work this way.

First, you get the problem with initialization which has been discussed in the other replies. If you initialize once, you do not have this problem.

Second, I am not at all certain that you get a valid sequence of random numbers; rather, you get a collection of the first number of multiple different sequences which are seeded automatically based on computer time. I am not certain that these numbers will pass the tests that confirm the randomness of the sequence.

Quick easy way to migrate SQLite3 to MySQL?

Here is a python script, built off of Shalmanese's answer and some help from Alex martelli over at Translating Perl to Python

I'm making it community wiki, so please feel free to edit, and refactor as long as it doesn't break the functionality (thankfully we can just roll back) - It's pretty ugly but works

use like so (assuming the script is called

sqlite3 sample.db .dump | python > dump.sql

Which you can then import into mysql

note - you need to add foreign key constrains manually since sqlite doesn't actually support them

here is the script:

#!/usr/bin/env python

import re
import fileinput

def this_line_is_useless(line):
    useless_es = [
        'PRAGMA foreign_keys=OFF',
    for useless in useless_es:
        if, line):
            return True

def has_primary_key(line):
    return bool('PRIMARY KEY', line))

searching_for_end = False
for line in fileinput.input():
    if this_line_is_useless(line):

    # this line was necessary because '');
    # would be converted to \'); which isn't appropriate
    if re.match(r".*, ''\);", line):
        line = re.sub(r"''\);", r'``);', line)

    if re.match(r'^CREATE TABLE.*', line):
        searching_for_end = True

    m ='CREATE TABLE "?(\w*)"?(.*)', line)
    if m:
        name, sub = m.groups()
        line = "DROP TABLE IF EXISTS %(name)s;\nCREATE TABLE IF NOT EXISTS `%(name)s`%(sub)s\n"
        line = line % dict(name=name, sub=sub)
        m ='INSERT INTO "(\w*)"(.*)', line)
        if m:
            line = 'INSERT INTO %s%s\n' % m.groups()
            line = line.replace('"', r'\"')
            line = line.replace('"', "'")
    line = re.sub(r"([^'])'t'(.)", "\1THIS_IS_TRUE\2", line)
    line = line.replace('THIS_IS_TRUE', '1')
    line = re.sub(r"([^'])'f'(.)", "\1THIS_IS_FALSE\2", line)
    line = line.replace('THIS_IS_FALSE', '0')

    # Add auto_increment if it is not there since sqlite auto_increments ALL
    # primary keys
    if searching_for_end:
        if"integer(?:\s+\w+)*\s*PRIMARY KEY(?:\s+\w+)*\s*,", line):
            line = line.replace("PRIMARY KEY", "PRIMARY KEY AUTO_INCREMENT")
        # replace " and ' with ` because mysql doesn't like quotes in CREATE commands 
        if line.find('DEFAULT') == -1:
            line = line.replace(r'"', r'`').replace(r"'", r'`')
            parts = line.split('DEFAULT')
            parts[0] = parts[0].replace(r'"', r'`').replace(r"'", r'`')
            line = 'DEFAULT'.join(parts)

    # And now we convert it back (see above)
    if re.match(r".*, ``\);", line):
        line = re.sub(r'``\);', r"'');", line)

    if searching_for_end and re.match(r'.*\);', line):
        searching_for_end = False

    if re.match(r"CREATE INDEX", line):
        line = re.sub('"', '`', line)

    if re.match(r"AUTOINCREMENT", line):
        line = re.sub("AUTOINCREMENT", "AUTO_INCREMENT", line)

    print line,

How do you configure tomcat to bind to a single ip address (localhost) instead of all addresses?

it's well documented here:

How do I bind to a specific ip address? - "Each Connector element allows an address property. See the HTTP Connector docs or the AJP Connector docs". And HTTP Connectors docs:

Standard Implementation -> address

"For servers with more than one IP address, this attribute specifies which address will be used for listening on the specified port. By default, this port will be used on all IP addresses associated with the server."

Converting List<Integer> to List<String>

You can't avoid the "boxing overhead"; Java's faux generic containers can only store Objects, so your ints must be boxed into Integers. In principle it could avoid the downcast from Object to Integer (since it's pointless, because Object is good enough for both String.valueOf and Object.toString) but I don't know if the compiler is smart enough to do that. The conversion from String to Object should be more or less a no-op, so I would be disinclined to worry about that one.

What are some good SSH Servers for windows?

VanDyke VShell is the best Windows SSH Server I've ever worked with. It is kind of expensive though ($250). If you want a free solution, freeSSHd works okay. The CYGWIN solution is always an option, I've found, however, that it is a lot of work & overhead just to get SSH.

Validate decimal numbers in JavaScript - IsNumeric()

This way seems to work well:

function IsNumeric(input){
    var RE = /^-{0,1}\d*\.{0,1}\d+$/;
    return (RE.test(input));

In one line:

const IsNumeric = (num) => /^-{0,1}\d*\.{0,1}\d+$/.test(num);

And to test it:

const IsNumeric = (num) => /^-{0,1}\d*\.{0,1}\d+$/.test(num);_x000D_
    function TestIsNumeric(){_x000D_
        var results = ''_x000D_
        results += (IsNumeric('-1')?"Pass":"Fail") + ": IsNumeric('-1') => true\n";_x000D_
        results += (IsNumeric('-1.5')?"Pass":"Fail") + ": IsNumeric('-1.5') => true\n";_x000D_
        results += (IsNumeric('0')?"Pass":"Fail") + ": IsNumeric('0') => true\n";_x000D_
        results += (IsNumeric('0.42')?"Pass":"Fail") + ": IsNumeric('0.42') => true\n";_x000D_
        results += (IsNumeric('.42')?"Pass":"Fail") + ": IsNumeric('.42') => true\n";_x000D_
        results += (!IsNumeric('99,999')?"Pass":"Fail") + ": IsNumeric('99,999') => false\n";_x000D_
        results += (!IsNumeric('0x89f')?"Pass":"Fail") + ": IsNumeric('0x89f') => false\n";_x000D_
        results += (!IsNumeric('#abcdef')?"Pass":"Fail") + ": IsNumeric('#abcdef') => false\n";_x000D_
        results += (!IsNumeric('1.2.3')?"Pass":"Fail") + ": IsNumeric('1.2.3') => false\n";_x000D_
        results += (!IsNumeric('')?"Pass":"Fail") + ": IsNumeric('') => false\n";_x000D_
        results += (!IsNumeric('blah')?"Pass":"Fail") + ": IsNumeric('blah') => false\n";_x000D_
        return results;_x000D_
.as-console-wrapper { max-height: 100% !important; top: 0; }

I borrowed that regex from Explanation:

/^ match beginning of string
-{0,1} optional negative sign
\d* optional digits
\.{0,1} optional decimal point
\d+ at least one digit
$/ match end of string

How to generate a core dump in Linux on a segmentation fault?

There are more things that may influence the generation of a core dump. I encountered these:

  • the directory for the dump must be writable. By default this is the current directory of the process, but that may be changed by setting /proc/sys/kernel/core_pattern.
  • in some conditions, the kernel value in /proc/sys/fs/suid_dumpable may prevent the core to be generated.

There are more situations which may prevent the generation that are described in the man page - try man core.

How to round up the result of integer division?

A generic method, whose result you can iterate over may be of interest:

public static Object[][] chunk(Object[] src, int chunkSize) {

    int overflow = src.length%chunkSize;
    int numChunks = (src.length/chunkSize) + (overflow>0?1:0);
    Object[][] dest = new Object[numChunks][];      
    for (int i=0; i<numChunks; i++) {
        dest[i] = new Object[ (i<numChunks-1 || overflow==0) ? chunkSize : overflow ];
        System.arraycopy(src, i*chunkSize, dest[i], 0, dest[i].length); 
    return dest;

Warning: Found conflicts between different versions of the same dependent assembly

Basically this happens when the assemblies you're referencing have "Copy Local" set to "True", meaning that a copy of the DLL is placed in the bin folder along with your exe.

Since Visual Studio will copy all of the dependencies of a referenced assembly as well, it's possible to end up with two different builds of the same assembly being referred to. This is more likely to happen if your projects are in separate solutions, and can therefore be compiled separately.

The way I've gotten around it is to set Copy Local to False for references in assembly projects. Only do it for executables/web applications where you need the assembly for the finished product to run.

Hope that makes sense!

When should you use 'friend' in C++?

Friend comes handy when you are building a container and you want to implement an iterator for that class.

How do I send a file as an email attachment using Linux command line?

metamail has the tool metasend

metasend -f mysqlbackup.sql.gz -t [email protected] -s Backup -m application/x-gzip -b

What is the most effective way for float and double comparison?

Unfortunately, even your "wasteful" code is incorrect. EPSILON is the smallest value that could be added to 1.0 and change its value. The value 1.0 is very important — larger numbers do not change when added to EPSILON. Now, you can scale this value to the numbers you are comparing to tell whether they are different or not. The correct expression for comparing two doubles is:

if (fabs(a - b) <= DBL_EPSILON * fmax(fabs(a), fabs(b)))
    // ...

This is at a minimum. In general, though, you would want to account for noise in your calculations and ignore a few of the least significant bits, so a more realistic comparison would look like:

if (fabs(a - b) <= 16 * DBL_EPSILON * fmax(fabs(a), fabs(b)))
    // ...

If comparison performance is very important to you and you know the range of your values, then you should use fixed-point numbers instead.

When to use IList and when to use List

In situations I usually come across, I rarely use IList directly.

Usually I just use it as an argument to a method

void ProcessArrayData(IList almostAnyTypeOfArray)
    // Do some stuff with the IList array

This will allow me to do generic processing on almost any array in the .NET framework, unless it uses IEnumerable and not IList, which happens sometimes.

It really comes down to the kind of functionality you need. I'd suggest using the List class in most cases. IList is best for when you need to make a custom array that could have some very specific rules that you'd like to encapsulate within a collection so you don't repeat yourself, but still want .NET to recognize it as a list.

How to generate sample XML documents from their DTD or XSD?

The OpenXSD library mentions that they have support for generating XML instances based on the XSD. Check that out.

What Ruby IDE do you prefer?

NetBeans is good because you can use it on Windows and Mac OS X.

How to select the nth row in a SQL database table?

WHERE  n = (SELECT COUNT( _rowid)
              FROM emp b
             WHERE a. _rowid >= b. _rowid);

What is a lambda (function)?

A Lambda Function, or a Small Anonymous Function, is a self-contained block of functionality that can be passed around and used in your code. Lambda has different names in different programming languages – Lambda in Python and Kotlin, Closure in Swift, or Block in C and Objective-C. Although lambda's meaning is quite similar for these languages it has slight distinctions sometimes.

Let's see how Lambda (Closure) works in Swift 4.2 with sorted() method – from normal function till the shortest expression:

let coffee: [String] = ["Cappuccino", "Espresso", "Latte", "Ristretto"]

1. Normal Function

func backward(_ n1: String, _ n2: String) -> Bool {
    return n1 > n2
var reverseOrder = coffee.sorted(by: backward)

// RESULT: ["Ristretto", "Latte", "Espresso", "Cappuccino"]

2. Closure Expression

reverseOrder = coffee.sorted(by: { (n1: String, n2: String) -> Bool in
    return n1 > n2

3. Inline Closure Expression

reverseOrder = coffee.sorted(by: { (n1: String, n2: String) -> Bool in return n1 > n2 } )

4. Inferring Type From Context

reverseOrder = coffee.sorted(by: { n1, n2 in return n1 > n2 } )

5. Implicit Returns from Single-Expression Closures

reverseOrder = coffee.sorted(by: { n1, n2 in n1 > n2 } )

6. Shorthand Argument Names

reverseOrder = coffee.sorted(by: { $0 > $1 } )

// $0 and $1 are closure’s first and second String arguments.

7. Operator Methods

reverseOrder = coffee.sorted(by: >)

// RESULT: ["Ristretto", "Latte", "Espresso", "Cappuccino"]

Hope this helps.

Parse usable Street Address, City, State, Zip from a string

This type of problem is hard to solve because of underlying ambiguities in the data.

Here is a Perl based solution that defines a recursive descent grammar tree based on regular expressions to parse many valid combination of street addresses: . This includes sub properties within an address such as: 12 1st Avenue N Suite # 2 Somewhere CA 12345 USA

It is similar to mentioned above, but also works for addresses that are not from the USA, such as the UK, Australia and Canada.

Here is the output for one of your sample addresses. Note that the name section would need to be removed first from "A. P. Croll & Son 2299 Lewes-Georgetown Hwy, Georgetown, DE 19947" to reduce it to "2299 Lewes-Georgetown Hwy, Georgetown, DE 19947". This is easily achieved by removing all data up to the first number found in the string.

Non matching part       ''
Error                   '0'
Error descriptions      ''
Case all                '2299 Lewes-Georgetown Hwy Georgetown DE 19947'
COMPONENTS              ''
country                 ''
po_box_type             ''
post_box                ''
post_code               '19947'
pre_cursor              ''
property_identifier     '2299'
property_name           ''
road_box                ''
street                  'Lewes-Georgetown'
street_direction        ''
street_type             'Hwy'
sub_property_identifier ''
subcountry              'DE'
suburb                  'Georgetown'

How to redirect siteA to siteB with A or CNAME records

Try changing it to "subdomain ->"

The CNAME is an alias for a certain domain, so when you go to the control panel for, you shouldn't have to enter the whole name into the CNAME alias.

As far as the error you are getting, can you log onto and check the logs?

What do "branch", "tag" and "trunk" mean in Subversion repositories?

The trunk directory is the directory that you're probably most familiar with, because it is used to hold the most recent changes. Your main codebase should be in trunk.

The branches directory is for holding your branches, whatever they may be.

The tags directory is basically for tagging a certain set of files. You do this for things like releases, where you want "1.0" to be these files at these revisions and "1.1" to be these files at these revisions. You usually don't modify tags once they're made. For more information on tags, see Chapter 4. Branching and Merging (in Version Control with Subversion).

Convert a string to an enum in C#

object Enum.Parse(System.Type enumType, string value, bool ignoreCase);

So if you had an enum named mood it would look like this:

   enum Mood

   // ...
   Mood m = (Mood) Enum.Parse(typeof(Mood), "Happy", true);
   Console.WriteLine("My mood is: {0}", m.ToString());

How do I convert a file path to a URL in ASP.NET

This worked for me:

HttpContext.Current.Request.Url.GetLeftPart(UriPartial.Authority) + HttpRuntime.AppDomainAppVirtualPath + "ImageName";

Reading Excel files from C#

Forgive me if I am off-base here, but isn't this what the Office PIA's are for?

Changing the resolution of a VNC session in linux

I think that depends on your window manager.

I'm a windows user, so this might be a wrong guess, but: Isn't there something called X-Server running on linux machines - at least on ones that might be interesting targets for VNC - that you can connect to with "X-Clients"?

VNC just takes everything that's on the screen and "tunnels it through your network". If I'm not totally wrong then the "X" protocol should give you the chance to use your client's desktop resolution.

Give X-Server on Wikipedia a try, that might give you a rough overview.

What's the best way to validate an XML file against an XSD file?

Since this is a popular question, I will point out that java can also validate against "referred to" xsd's, for instance if the .xml file itself specifies XSD's in the header, using xsi:schemaLocation or xsi:noNamespaceSchemaLocation (or xsi for particular namespaces) ex:

<document xmlns:xsi=""

or schemaLocation (always a list of namespace to xsd mappings)

<document xmlns:xsi=""

The other answers work here as well, because the .xsd files "map" to the namespaces declared in the .xml file, because they declare a namespace, and if matches up with the namespace in the .xml file, you're good. But sometimes it's convenient to be able to have a custom resolver...

From the javadocs: "If you create a schema without specifying a URL, file, or source, then the Java language creates one that looks in the document being validated to find the schema it should use. For example:"

SchemaFactory factory = SchemaFactory.newInstance("");
Schema schema = factory.newSchema();

and this works for multiple namespaces, etc. The problem with this approach is that the xmlsns:xsi is probably a network location, so it'll by default go out and hit the network with each and every validation, not always optimal.

Here's an example that validates an XML file against any XSD's it references (even if it has to pull them from the network):

  public static void verifyValidatesInternalXsd(String filename) throws Exception {
    InputStream xmlStream = new new FileInputStream(filename);
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    DocumentBuilder builder = factory.newDocumentBuilder();
    builder.setErrorHandler(new RaiseOnErrorHandler());
    builder.parse(new InputSource(xmlStream));

  public static class RaiseOnErrorHandler implements ErrorHandler {
    public void warning(SAXParseException e) throws SAXException {
      throw new RuntimeException(e);
    public void error(SAXParseException e) throws SAXException {
      throw new RuntimeException(e);
    public void fatalError(SAXParseException e) throws SAXException {
      throw new RuntimeException(e);

You can avoid pulling referenced XSD's from the network, even though the xml files reference url's, by specifying the xsd manually (see some other answers here) or by using an "XML catalog" style resolver. Spring apparently also can intercept the URL requests to serve local files for validations. Or you can set your own via setResourceResolver, ex:

Source xmlFile = new StreamSource(xmlFileLocation);
SchemaFactory schemaFactory = SchemaFactory
Schema schema = schemaFactory.newSchema();
Validator validator = schema.newValidator();
validator.setResourceResolver(new LSResourceResolver() {
  public LSInput resolveResource(String type, String namespaceURI,
                                 String publicId, String systemId, String baseURI) {
    InputSource is = new InputSource(
                          // or lookup by URI, etc...
    return new Input(is); // for class Input see 

See also here for another tutorial.

I believe the default is to use DOM parsing, you can do something similar with SAX parser that is validating as well saxReader.setEntityResolver(your_resolver_here);

How can I determine whether a specific file is open in Windows?

There is a program "OpenFiles", seems to be part of windows 7. Seems that it can do what you want. It can list files opened by remote users (through file share) and, after calling "openfiles /Local on" and a system restart, it should be able to show files opened locally. The latter is said to have performance penalties.

Hidden Features of Java

The addition of the for-each loop construct in 1.5. I <3 it.

// For each Object, instantiated as foo, in myCollection
for(Object foo: myCollection) {

And can be used in nested instances:

for (Suit suit : suits)
  for (Rank rank : ranks)
    sortedDeck.add(new Card(suit, rank));

The for-each construct is also applicable to arrays, where it hides the index variable rather than the iterator. The following method returns the sum of the values in an int array:

// Returns the sum of the elements of a
int sum(int[] a) {
  int result = 0;
  for (int i : a)
    result += i;
  return result;

Link to the Sun documentation

Sorting an IList in C#

try this  **USE ORDER BY** :

   public class Employee
        public string Id { get; set; }
        public string Name { get; set; }

 private static IList<Employee> GetItems()
            List<Employee> lst = new List<Employee>();

            lst.Add(new Employee { Id = "1", Name = "Emp1" });
            lst.Add(new Employee { Id = "2", Name = "Emp2" });
            lst.Add(new Employee { Id = "7", Name = "Emp7" });
            lst.Add(new Employee { Id = "4", Name = "Emp4" });
            lst.Add(new Employee { Id = "5", Name = "Emp5" });
            lst.Add(new Employee { Id = "6", Name = "Emp6" });
            lst.Add(new Employee { Id = "3", Name = "Emp3" });

            return lst;

**var lst = GetItems().AsEnumerable();

            var orderedLst = lst.OrderBy(t => t.Id).ToList();

            orderedLst.ForEach(emp => Console.WriteLine("Id - {0} Name -{1}", emp.Id, emp.Name));**

How to change the icon of .bat file programmatically?

One of the way you can achieve this is:

  1. Create an executable Jar file
  2. Create a batch file to run the above jar and launch the desktop java application.
  3. Use Batch2Exe converter and covert to batch file to Exe.
  4. During above conversion, you can change the icon to that of your choice.(must of valid .ico file)
  5. Place the short cut for the above exe on desktop.

Now your java program can be opened in a fancy way just like any other MSWindows apps.! :)

What's the best UML diagramming tool?

You can also check out Lucid Chart for uml and other types of diagramming.

How to retrieve a file from a server via SFTP?

Though answers above were very helpful, I've spent a day to make them work, facing various exceptions like "broken channel", "rsa key unknown" and "packet corrupt".

Below is a working reusable class for SFTP FILES UPLOAD/DOWNLOAD using JSch library.

Upload usage:

SFTPFileCopy upload = new SFTPFileCopy(true, /path/to/sourcefile.png", /path/to/destinationfile.png");

Download usage:

SFTPFileCopy download = new SFTPFileCopy(false, "/path/to/sourcefile.png", "/path/to/destinationfile.png");

The class code:

import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelSftp;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.Session;
import com.jcraft.jsch.UIKeyboardInteractive;
import com.jcraft.jsch.UserInfo;
import javax.swing.JOptionPane;
import menue.Menue;

public class SFTPFileCopy1 {

    public SFTPFileCopy1(boolean upload, String sourcePath, String destPath) throws FileNotFoundException, IOException {
        Session session = null;
        Channel channel = null;
        ChannelSftp sftpChannel = null;
        try {
            JSch jsch = new JSch();
            session = jsch.getSession("login", "", 22);

            UserInfo ui = new MyUserInfo() {
                public void showMessage(String message) {

                    JOptionPane.showMessageDialog(null, message);


                public boolean promptYesNo(String message) {

                    Object[] options = {"yes", "no"};

                    int foo = JOptionPane.showOptionDialog(null,
                            null, options, options[0]);

                    return foo == 0;


            session.setConfig("StrictHostKeyChecking", "no");
            channel = session.openChannel("sftp");
            sftpChannel = (ChannelSftp) channel;

            if (upload) { // File upload.
                byte[] bufr = new byte[(int) new File(sourcePath).length()];
                FileInputStream fis = new FileInputStream(new File(sourcePath));
                ByteArrayInputStream fileStream = new ByteArrayInputStream(bufr);
                sftpChannel.put(fileStream, destPath);
            } else { // File download.
                byte[] buffer = new byte[1024];
                BufferedInputStream bis = new BufferedInputStream(sftpChannel.get(sourcePath));
                OutputStream os = new FileOutputStream(new File(destPath));
                BufferedOutputStream bos = new BufferedOutputStream(os);
                int readCount;
                while ((readCount = > 0) {
                    bos.write(buffer, 0, readCount);
        } catch (Exception e) {
        } finally {
            if (sftpChannel != null) {
            if (channel != null) {
            if (session != null) {

    public static abstract class MyUserInfo
            implements UserInfo, UIKeyboardInteractive {

        public String getPassword() {
            return null;

        public boolean promptYesNo(String str) {
            return false;

        public String getPassphrase() {
            return null;

        public boolean promptPassphrase(String message) {
            return false;

        public boolean promptPassword(String message) {
            return false;

        public void showMessage(String message) {

        public String[] promptKeyboardInteractive(String destination,
                String name,
                String instruction,
                String[] prompt,
                boolean[] echo) {

            return null;

LINQ-to-SQL vs stored procedures?

The outcome can be summarized as

LinqToSql for small sites, and prototypes. It really saves time for Prototyping.

Sps : Universal. I can fine tune my queries and always check ActualExecutionPlan / EstimatedExecutionPlan.

fopen deprecated warning

Many of Microsoft's secure functions, including fopen_s(), are part of C11, so they should be portable now. You should realize that the secure functions differ in exception behaviors and sometimes in return values. Additionally you need to be aware that while these functions are standardized, it's an optional part of the standard (Annex K) that at least glibc (default on Linux) and FreeBSD's libc don't implement.

However, I fought this problem for a few years. I posted a larger set of conversion macros here., For your immediate problem, put the following code in an include file, and include it in your source code:

#pragma once
#if !defined(FCN_S_MACROS_H)
   #define   FCN_S_MACROS_H

   #include <cstdio>
   #include <string> // Need this for _stricmp
   using namespace std;

   // _MSC_VER = 1400 is MSVC 2005. _MSC_VER = 1600 (MSVC 2010) was the current
   // value when I wrote (some of) these macros.

   #if (defined(_MSC_VER) && (_MSC_VER >= 1400) )

      inline extern
      FILE*   fcnSMacro_fopen_s(char *fname, char *mode)
      {  FILE *fptr;
         fopen_s(&fptr, fname, mode);
         return fptr;
      #define fopen(fname, mode)            fcnSMacro_fopen_s((fname), (mode))

      #define fopen_s(fp, fmt, mode)        *(fp)=fopen( (fmt), (mode))

   #endif //_MSC_VER

#endif // FCN_S_MACROS_H

Of course this approach does not implement the expected exception behavior.

How can I remove a child node in HTML using JavaScript?

To answer the original question - there are various ways to do this, but the following would be the simplest.

If you already have a handle to the child node that you want to remove, i.e. you have a JavaScript variable that holds a reference to it:


Obviously, if you are not using one of the numerous libraries that already do this, you would want to create a function to abstract this out:

function removeElement(node) {

EDIT: As has been mentioned by others: if you have any event handlers wired up to the node you are removing, you will want to make sure you disconnect those before the last reference to the node being removed goes out of scope, lest poor implementations of the JavaScript interpreter leak memory.

How can I permanently enable line numbers in IntelliJ?

IntelliJ 2019 community edition has line number by default. If you want to show or hide line numbers, go to the following settings to change the appearance.

go to ? File ? Setting ? Editor ? General ? Appearance ? [Check] Show line numbers


mysqli or PDO - what are the pros and cons?

There's one thing to keep in mind.

Mysqli does not support fetch_assoc() function which would return the columns with keys representing column names. Of course it's possible to write your own function to do that, it's not even very long, but I had really hard time writing it (for non-believers: if it seems easy to you, try it on your own some time and don't cheat :) )

What's the difference between struct and class in .NET?

Well, for starters, a struct is passed by value rather than by reference. Structs are good for relatively simple data structures, while classes have a lot more flexibility from an architectural point of view via polymorphism and inheritance.

Others can probably give you more detail than I, but I use structs when the structure that I am going for is simple.

Mercurial stuck "waiting for lock"

I had the same problem. Got the following message when I tried to commit:

waiting for lock on working directory of <MyProject> held by '...'

hg debuglock showed this:

lock:  free
wlock:  (66722s)

So I did the following command, and that fixed the problem for me:

hg debuglocks -W

Using Win7 and TortoiseHg 4.8.7.

How do I tell if a variable has a numeric value in Perl?

You can use Regular Expressions to determine if $foo is a number (or not).

Take a look here: How do I determine whether a scalar is a number

What is the easiest way to parse an INI File in C++?

Unless you plan on making the app cross-platform, using the Windows API calls would be the best way to go. Just ignore the note in the API documentation about being provided only for 16-bit app compatibility.

How do you get a directory listing in C?

I've created an open source (BSD) C header that deals with this problem. It currently supports POSIX and Windows. Please check it out:

tinydir_dir dir;
tinydir_open(&dir, "/path/to/dir");

while (dir.has_next)
    tinydir_file file;
    tinydir_readfile(&dir, &file);

    if (file.is_dir)



How should I unit test multithreaded code?

You may use EasyMock.makeThreadSafe to make testing instance threadsafe

Calling the base constructor in C#

public class MyExceptionClass : Exception
    public MyExceptionClass(string message,
      Exception innerException): base(message, innerException)
        //other stuff here

You can pass inner exception to one of the constructors.

Browse for a directory in C#

You could just use the FolderBrowserDialog class from the System.Windows.Forms namespace.

Case-insensitive string comparison in C++

The Boost.String library has a lot of algorithms for doing case-insenstive comparisons and so on.

You could implement your own, but why bother when it's already been done?

How do you kill all current connections to a SQL Server 2005 database?

I'm using SQL Server 2008 R2, my DB was already set for single user and there was a connection that restricted any action on the database. Thus the recommended SQLMenace's solution responded with error. Here is one that worked in my case.

How to parse XML using vba

Add reference Project->References Microsoft XML, 6.0 and you can use example code:

    Dim xml As String

    xml = "<root><person><name>Me </name> </person> <person> <name>No Name </name></person></root> "
    Dim oXml As MSXML2.DOMDocument60
    Set oXml = New MSXML2.DOMDocument60
    oXml.loadXML xml
    Dim oSeqNodes, oSeqNode As IXMLDOMNode

    Set oSeqNodes = oXml.selectNodes("//root/person")
    If oSeqNodes.length = 0 Then
       'show some message
        For Each oSeqNode In oSeqNodes
             Debug.Print oSeqNode.selectSingleNode("name").Text
    End If 

be careful with xml node //Root/Person is not same with //root/person, also selectSingleNode("Name").text is not same with selectSingleNode("name").text

Refresh Excel VBA Function Results

If you include ALL references to the spreadsheet data in the UDF parameter list, Excel will recalculate your function whenever the referenced data changes:

Public Function doubleMe(d As Variant)
    doubleMe = d * 2
End Function

You can also use Application.Volatile, but this has the disadvantage of making your UDF always recalculate - even when it does not need to because the referenced data has not changed.

Public Function doubleMe()
    doubleMe = Worksheets("Fred").Range("A1") * 2
End Function

What are the proper permissions for an upload folder with PHP/Apache?

What is important is that the apache user and group should have minimum read access and in some cases execute access. For the rest you can give 0 access.

This is the most safe setting.

How can you customize the numbers in an ordered list?

I have it. Try the following:

<style type='text/css'>

    ol { counter-reset: item; }

    li { display: block; }

    li:before { content: counter(item) ")"; counter-increment: item; 
        display: inline-block; width: 50px; }


The catch is that this definitely won't work on older or less compliant browsers: display: inline-block is a very new property.

LINQ query on a DataTable

you can try this, but you must be sure the type of values for each Column

List<MyClass> result = myDataTable.AsEnumerable().Select(x=> new MyClass(){
     Property1 = (string)x.Field<string>("ColumnName1"),
     Property2 = (int)x.Field<int>("ColumnName2"),
     Property3 = (bool)x.Field<bool>("ColumnName3"),    

How to programmatically send SMS on the iPhone?

- (void)sendSMS:(NSString *)bodyOfMessage recipientList:(NSArray *)recipients
    UIPasteboard *pasteboard = [UIPasteboard generalPasteboard];
    UIImage *ui =resultimg.image;
    pasteboard.image = ui;
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"sms:"]];

Compare a date string to datetime in SQL Server?

This function Cast(Floor(Cast(GetDate() As Float)) As DateTime) returns a datetime datatype with the time portion removed and could be used as so.

Cast(Floor(Cast(Column_DateTime As Float)) As DateTime) = '14-AUG-2008'


SET      @p_date = Cast('14 AUG 2008' as DateTime)

FROM     table1
WHERE    Cast(Floor(Cast(column_datetime As Float)) As DateTime) = @p_date

Why are my PowerShell scripts not running?

import-module IISAdministration;

function StartSite{
        Start-IISSite -Name $sitename;
        Write-Host "Site was started";
        Write-Error "Error while staring the IISSite";

function StopSite{
        Stop-IISSite -Name $sitename -confirm:$False; # Supress interaction inputs
        Write-Host "Site was stopped";
            Write-Error "Error while stopping the IISSite";
function ReplaceSiteFiles{
        Get-ChildItem -Path A:\APPS\CreditApp -Recurse | Foreach-Object {Remove-Item -Recurse -Path $_.FullName} # Remove file from AppPool Directory
        Expand-Archive A:\Staging\LTA\Installers\CreditApp\ -DestinationPath A:\APPS\ # Extract files from zip
        Write-Host "Site files replaced successfully!";
    catch [System.SystemException]{
        Write-Host "Error while replacing the site files";
        Write-Host $_

## Start Here
$site=Get-IISSite -Name "Default Web Site";

Write-Host $site

if($site.length -eq 1){

    $siteState = $site.state;
    Write-Host "The Site Exists with state: ${siteState}";

    switch ($siteState)
        'started' { 
                    StopSite -sitename $;
                    StartSite -sitename $;
        'stopped' { 
                    StartSite -sitename $;
        default { "Deployment failed! Site state could not be determined.";}

    Write-Error "Invalid! Site does not exists";

##  End Here

Differences between MySQL and SQL Server

Frankly, I can't find a single reason to use MySQL rather than MSSQL. The issue before used to be cost but SQL Server 2005 Express is free and there are lots of web hosting companies which offer full hosting with sql server for less than $5.00 a month.

MSSQL is easier to use and has many features which do not exist in MySQL.

How can I set up an editor to work with Git on Windows?

Building on Darren's answer, to use Notepad++ you can simply do this (all on one line):

git config --global core.editor "'C:/Program Files/Notepad++/notepad++.exe' -multiInst -notabbar -nosession -noPlugin"

Obviously, the C:/Program Files/Notepad++/notepad++.exe part should be the path to the Notepad++ executable on your system. For example, it might be C:/Program Files (x86)/Notepad++/notepad++.exe.

It works like a charm for me.

Oracle - What TNS Names file am I using?

Shouldn't it always be "$ORACLE_ HOME/network/admin/tnsnames.ora"? Then you can just do "echo $oracle_ home" or the *nix equivalent.

@Pete Holberton You are entirely correct. Which reminds me, there's another monkey wrench in the works called TWO_ TASK

TNS_ADMIN is an environment variable that points to the directory where the SQL*Net configuration files (like sqlnet.ora and tnsnames.ora) are located.

Convert a hexadecimal string to an integer efficiently in C?

Why is a code solution that works getting voted down? Sure, it's ugly ...

Perhaps because as well as being ugly it isn't educational and doesn't work. Also, I suspect that like me, most people don't have the power to edit at present (and judging by the rank needed - never will).

The use of an array can be good for efficiency, but that's not mentioned in this code. It also takes no account of upper and lower case so it does not work for the example supplied in the question. FFFFFFFE

How do I create a Linked List Data Structure in Java?

//slightly improved code without using collection framework

package com.test;

public class TestClass {

    private static Link last;
    private static Link first;

    public static void main(String[] args) {

        for(int i=0;i<5;i++){


    protected  static class Link {
        private int data;
        private Link nextlink;

        public Link(int d1) {
   = d1;

        public static void insert(int d1) {
            Link a = new Link(d1);
            a.nextlink = null;
            if (first != null) {
                last.nextlink = a;
                last = a;
            } else {
                first = a;
                last = a;
            System.out.println("Inserted -:"+d1);

        public static void deletefromFirst() {
                System.out.println("Deleting -:";
                first = first.nextlink;
                System.out.println("No elements in Linked List");

        public static void printList() {
            System.out.println("Elements in the list are");
            Link temp = first;
            while (temp != null) {
                temp = temp.nextlink;

How do I remove duplicates from a C# array?

The best way? Hard to say, the HashSet approach looks fast, but (depending on the data) using a sort algorithm (CountSort ?) can be much faster.

using System;
using System.Collections.Generic;
using System.Linq;
class Program
    static void Main()
        Random r = new Random(0); int[] a, b = new int[1000000];
        for (int i = b.Length - 1; i >= 0; i--) b[i] = r.Next(b.Length);
        a = new int[b.Length]; Array.Copy(b, a, b.Length);
        a = dedup0(a); Console.WriteLine(a.Length);
        a = new int[b.Length]; Array.Copy(b, a, b.Length);
        var w = System.Diagnostics.Stopwatch.StartNew();
        a = dedup0(a); Console.WriteLine(w.Elapsed); Console.Read();

    static int[] dedup0(int[] a)  // 48 ms  
        return new HashSet<int>(a).ToArray();

    static int[] dedup1(int[] a)  // 68 ms
        Array.Sort(a); int i = 0, j = 1, k = a.Length; if (k < 2) return a;
        while (j < k) if (a[i] == a[j]) j++; else a[++i] = a[j++];
        Array.Resize(ref a, i + 1); return a;

    static int[] dedup2(int[] a)  //  8 ms
        var b = new byte[a.Length]; int c = 0;
        for (int i = 0; i < a.Length; i++) 
            if (b[a[i]] == 0) { b[a[i]] = 1; c++; }
        a = new int[c];
        for (int j = 0, i = 0; i < b.Length; i++) if (b[i] > 0) a[j++] = i;
        return a;

Almost branch free. How? Debug mode, Step Into (F11) with a small array: {1,3,1,1,0}

    static int[] dedupf(int[] a)  //  4 ms
        if (a.Length < 2) return a;
        var b = new byte[a.Length]; int c = 0, bi, ai, i, j;
        for (i = 0; i < a.Length; i++)
        { ai = a[i]; bi = 1 ^ b[ai]; b[ai] |= (byte)bi; c += bi; }
        a = new int[c]; i = 0; while (b[i] == 0) i++; a[0] = i++;
        for (j = 0; i < b.Length; i++) a[j += bi = b[i]] += bi * i; return a;

A solution with two nested loops might take some time, especially for larger arrays.

    static int[] dedup(int[] a)
        int i, j, k = a.Length - 1;
        for (i = 0; i < k; i++)
            for (j = i + 1; j <= k; j++) if (a[i] == a[j]) a[j--] = a[k--];
        Array.Resize(ref a, k + 1); return a;

How do you pass a function as a parameter in C?

I am gonna explain with a simple example code which takes a compare function as parameter to another sorting function. Lets say I have a bubble sort function that takes a custom compare function and uses it instead of a fixed if statement.

Compare Function

bool compare(int a, int b) {
    return a > b;

Now , the Bubble sort that takes another function as its parameter to perform comparison

Bubble sort function

void bubble_sort(int arr[], int n, bool (&cmp)(int a, int b)) {

    for (int i = 0;i < n - 1;i++) {
        for (int j = 0;j < (n - 1 - i);j++) {
            if (cmp(arr[j], arr[j + 1])) {
                swap(arr[j], arr[j + 1]);

Finally , the main which calls the Bubble sort function by passing the boolean compare function as argument.

int main()
    int i, n = 10, key = 11;
    int arr[10] = { 20, 22, 18, 8, 12, 3, 6, 12, 11, 15 };

    bubble_sort(arr, n, compare);
    cout<<"Sorted Order"<<endl;
    for (int i = 0;i < n;i++) {
        cout << arr[i] << " ";


Sorted Order
3 6 8 11 12 12 15 18 20 22

How do you create a static class in C++?

In C++ you want to create a static function of a class (not a static class).

class BitParser {
  static ... getBitAt(...) {

You should then be able to call the function using BitParser::getBitAt() without instantiating an object which I presume is the desired result.

Removing elements with in JavaScript

Array Filter method

var arr = [1, 2, 3]_x000D_
// ES5 syntax_x000D_
arr = arr.filter(function(item){ return item != 3 })_x000D_
// ES2015 syntax_x000D_
arr = arr.filter(item => item != 3)_x000D_
console.log( arr )

Select all columns except one in MySQL?

I would like to add another point of view in order to solve this problem, specially if you have a small number of columns to remove.

You could use a DB tool like MySQL Workbench in order to generate the select statement for you, so you just have to manually remove those columns for the generated statement and copy it to your SQL script.

In MySQL Workbench the way to generate it is:

Right click on the table -> send to Sql Editor -> Select All Statement.

grep a file, but show several surrounding lines?

grep astring myfile -A 5 -B 5

That will grep "myfile" for "astring", and show 5 lines before and after each match

Hidden Features of C#?

Cool trick to emulate functional "wildcard" arguments (like '_' in Haskell) when using lambdas:

(_, b, __) => b.DoStuff();  // only interested in b here

Storing a file in a database as opposed to the file system?

The overhead of having to parse a blob (image) into a byte array and then write it to disk in the proper file name and then reading it is enough of an overhead hit to discourage you from doing this too often, especially if the files are rather large.

Accessing MP3 metadata with Python

I would suggest mp3-tagger. Best thing about this is it is distributed under MIT License and supports all the required attributes.

- artist;
- album;
- song;
- track;
- comment;
- year;
- genre;
- band;
- composer;
- copyright;
- url;
- publisher.


from mp3_tagger import MP3File

# Create MP3File instance.
mp3 = MP3File('File_Name.mp3')

# Get all tags.
tags = mp3.get_tags()

It supports set, get, update and delete attributes of mp3 files.

Best implementation for Key Value Pair Data Structure?

There is a KeyValuePair built-in type. As a matter of fact, this is what the IDictionary is giving you access to when you iterate in it.

Also, this structure is hardly a tree, finding a more representative name might be a good exercise.

How to use XPath in Python?

You can use:


from xml.dom.ext.reader import Sax2
from xml import xpath
doc = Sax2.FromXmlFile('foo.xml').documentElement
for url in xpath.Evaluate('//@Url', doc):
  print url.value


import libxml2
doc = libxml2.parseFile('foo.xml')
for url in doc.xpathEval('//@Url'):
  print url.content

Entity Framework vs LINQ to SQL

Is LINQ to SQL Truly Dead? by Jonathan Allen for

Matt Warren describes [LINQ to SQL] as something that "was never even supposed to exist." Essentially, it was just supposed to be stand-in to help them develop LINQ until the real ORM was ready.


The scale of Entity Framework caused it to miss the .NET 3.5/Visual Studio 2008 deadline. It was completed in time for the unfortunately named ".NET 3.5 Service Pack 1", which was more like a major release than a service pack.


Developers do not like [ADO.NET Entity Framework] because of the complexity.


as of .NET 4.0, LINQ to Entities will be the recommended data access solution for LINQ to relational scenarios.

Generic type conversion FROM string

public class TypedProperty<T> : Property
    public T TypedValue
        get { return (T)(object)base.Value; }
        set { base.Value = value.ToString();}

I using converting via an object. It is a little bit simpler.

Best way to access a control on another form in Windows Forms?

You can

  1. Create a public method with needed parameter on child form and call it from parent form (with valid cast)
  2. Create a public property on child form and access it from parent form (with valid cast)
  3. Create another constructor on child form for setting form's initialization parameters
  4. Create custom events and/or use (static) classes

Best practice would be #4 if you are using non-modal forms.

What does the [Flags] Enum Attribute mean in C#?

To add Mode.Write:

Mode = Mode | Mode.Write;

100% Min Height CSS layout

I am using the following one: CSS Layout - 100 % height


The #container element of this page has a min-height of 100%. That way, if the content requires more height than the viewport provides, the height of #content forces #container to become longer as well. Possible columns in #content can then be visualised with a background image on #container; divs are not table cells, and you don't need (or want) the physical elements to create such a visual effect. If you're not yet convinced; think wobbly lines and gradients instead of straight lines and simple color schemes.

Relative positioning

Because #container has a relative position, #footer will always remain at its bottom; since the min-height mentioned above does not prevent #container from scaling, this will work even if (or rather especially when) #content forces #container to become longer.


Since it is no longer in the normal flow, padding-bottom of #content now provides the space for the absolute #footer. This padding is included in the scrolled height by default, so that the footer will never overlap the above content.

Scale the text size a bit or resize your browser window to test this layout.

html,body {
    height:100%; /* needed for container min-height */


h1 { 
    font:1.5em georgia,serif; 
    margin:0.5em 0;

h2 {
    font:1.25em georgia,serif; 
    margin:0 0 0.5em;
    h1, h2, a {

p { 
    margin:0 0 1em;

div#container {
    position:relative; /* needed for footer positioning*/
    margin:0 auto; /* center, not in IE5 */

    height:auto !important; /* real browsers */
    height:100%; /* IE6: treaded as min-height*/

    min-height:100%; /* real browsers */

div#header {
    background:#ddd url("../csslayout.gif") 98% 10px no-repeat;
    border-bottom:6px double gray;
    div#header p {

div#content {
    padding:1em 1em 5em; /* bottom padding for footer */
    div#content p {
        padding:0 1em;

div#footer {
    bottom:0; /* stick to bottom */
    border-top:6px double gray;
div#footer p {

Works fine for me.

Difference between EXISTS and IN in SQL?

The Exists keyword evaluates true or false, but IN keyword compare all value in the corresponding sub query column. Another one Select 1 can be use with Exists command. Example:

SELECT * FROM Temp1 where exists(select 1 from Temp2 where conditions...)

But IN is less efficient so Exists faster.

Is there a performance difference between i++ and ++i in C?

A better answer is that ++i will sometimes be faster but never slower.

Everyone seems to be assuming that i is a regular built-in type such as int. In this case there will be no measurable difference.

However if i is complex type then you may well find a measurable difference. For i++ you must make a copy of your class before incrementing it. Depending on what's involved in a copy it could indeed be slower since with ++it you can just return the final value.

Foo Foo::operator++()
  Foo oldFoo = *this; // copy existing value - could be slow
  // yadda yadda, do increment
  return oldFoo;

Another difference is that with ++i you have the option of returning a reference instead of a value. Again, depending on what's involved in making a copy of your object this could be slower.

A real-world example of where this can occur would be the use of iterators. Copying an iterator is unlikely to be a bottle-neck in your application, but it's still good practice to get into the habit of using ++i instead of i++ where the outcome is not affected.

How do I fix "for loop initial declaration used outside C99 mode" GCC error?

To switch to C99 mode in CodeBlocks, follow the next steps:

Click Project/Build options, then in tab Compiler Settings choose subtab Other options, and place -std=c99 in the text area, and click Ok.

This will turn C99 mode on for your Compiler.

I hope this will help someone!

C: What is the difference between ++i and i++?

Pre-crement means increment on the same line. Post-increment means increment after the line executes.

int j=0;
System.out.println(j); //0
System.out.println(j++); //0. post-increment. It means after this line executes j increments.

int k=0;
System.out.println(k); //0
System.out.println(++k); //1. pre increment. It means it increments first and then the line executes

When it comes with OR, AND operators, it becomes more interesting.

int m=0;
if((m == 0 || m++ == 0) && (m++ == 1)) { //false
/* in OR condition if first line is already true then compiler doesn't check the rest. It is technique of compiler optimization */
System.out.println("post-increment "+m);

int n=0;
if((n == 0 || n++ == 0) && (++n == 1)) { //true
System.out.println("pre-increment "+n); //1

In Array

System.out.println("In Array");
int[] a = { 55, 11, 15, 20, 25 } ;
int ii, jj, kk = 1, mm;
ii = ++a[1]; // ii = 12. a[1] = a[1] + 1
System.out.println(a[1]); //12

jj = a[1]++; //12
System.out.println(a[1]); //a[1] = 13

mm = a[1];//13
System.out.printf ( "\n%d %d %d\n", ii, jj, mm ) ; //12, 12, 13

for (int val: a) {
     System.out.print(" " +val); //55, 13, 15, 20, 25

In C++ post/pre-increment of pointer variable

#include <iostream>
using namespace std;

int main() {

    int x=10;
    int* p = &x;

    std::cout<<"address = "<<p<<"\n"; //prints address of x
    std::cout<<"address = "<<p<<"\n"; //prints (address of x) + sizeof(int)
    std::cout<<"address = "<<&x<<"\n"; //prints address of x

    std::cout<<"address = "<<++&x<<"\n"; //error. reference can't re-assign because it is fixed (immutable)

Execute script after specific delay using JavaScript

You can also use window.setInterval() to run some code repeatedly at a regular interval.

Escaping HTML strings with jQuery

This answer provides the jQuery and normal JS methods, but this is shortest without using the DOM:

unescape(escape("It's > 20% less complicated this way."))

Escaped string: It%27s%20%3E%2020%25%20less%20complicated%20this%20way.

If the escaped spaces bother you, try:

unescape(escape("It's > 20% less complicated this way.").replace(/%20/g, " "))

Escaped string: It%27s %3E 20%25 less complicated this way.

Unfortunately, the escape() function was deprecated in JavaScript version 1.5. encodeURI() or encodeURIComponent() are alternatives, but they ignore ', so the last line of code would turn into this:

decodeURI(encodeURI("It's > 20% less complicated this way.").replace(/%20/g, " ").replace("'", '%27'))

All major browsers still support the short code, and given the number of old websites, i doubt that will change soon.

JavaScript editor within Eclipse

Ganymede's version of WTP includes a revamped Javascript editor that's worth a try. The key version numbers are Eclipse 3.4 and WTP 3.0. See

Abstraction VS Information Hiding VS Encapsulation

Abstraction is hiding the implementation details by providing a layer over the basic functionality.

Information Hiding is hiding the data which is being affected by that implementation. Use of private and public comes under this. For example, hiding the variables of the classes.

Encapsulation is just putting all similar data and functions into a group e.g Class in programming; Packet in networking.

Through the use of Classes, we implement all three concepts - Abstraction, Information Hiding and Encapsulation

Initialize class fields in constructor or at declaration?

The design of C# suggests that inline initialization is preferred, or it wouldn't be in the language. Any time you can avoid a cross-reference between different places in the code, you're generally better off.

There is also the matter of consistency with static field initialization, which needs to be inline for best performance. The Framework Design Guidelines for Constructor Design say this:

? CONSIDER initializing static fields inline rather than explicitly using static constructors, because the runtime is able to optimize the performance of types that don’t have an explicitly defined static constructor.

"Consider" in this context means to do so unless there's a good reason not to. In the case of static initializer fields, a good reason would be if initialization is too complex to be coded inline.

SQL Server: Examples of PIVOTing String data


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C++ IDE for Linux?

I love how people completely miss the request in the original question for an IDE. Linux is NOT an IDE. That's just not what those words mean. I learned c and c++ using vi and gcc and make, and I'm not saying they aren't adequate tools, but they are NOT an IDE. Even if you use more elaborate tools like vim or emacs or whatever fancy editor you want, typing commands on a command line is not an IDE.

Also, you all know make exists as part of visual studio right? The idea that an IDE is "limiting" is just silly if you can use the IDE to speed some things, yet are still able to fall back on command line stuff when needed.

All that said, I'd suggest, as several above have, trying Code blocks. Its got decent code highlighting, a pretty effortless way to create a project, code it, run it, etc, that is the core of a real IDE, and seems fairly stable. Debugging sucks...I have never seen a decent interactive debugger in any linux/unix variant. gdb ain't it. If you're used to visual studio style debugging, you're pretty much out of luck.

Anyway, I'll go pack my things, I know the one-view-only linux crowd will shout this down and run me out of town in no time.

Algorithm to compare two images

If you're willing to consider a different approach altogether to detecting illegal copies of your images, you could consider watermarking. (from 1.4)

...inserts copyright information into the digital object without the loss of quality. Whenever the copyright of a digital object is in question, this information is extracted to identify the rightful owner. It is also possible to encode the identity of the original buyer along with the identity of the copyright holder, which allows tracing of any unauthorized copies.

While it's also a complex field, there are techniques that allow the watermark information to persist through gross image alteration: (from 1.9)

... any signal transform of reasonable strength cannot remove the watermark. Hence a pirate willing to remove the watermark will not succeed unless they debase the document too much to be of commercial interest.

of course, the faq calls implementing this approach: "...very challenging" but if you succeed with it, you get a high confidence of whether the image is a copy or not, rather than a percentage likelihood.

What does 'IISReset' do?

It stops and starts the services that IIS consists of.

You can think of it as closing the relevant program and starting it up again.

How Best to Compare Two Collections in Java and Act on Them?

I think the easiest way to do that is by using apache collections api - CollectionUtils.subtract(list1,list2) as long the lists are of the same type.