Programs & Examples On #Tdm mingw

Print all but the first three columns

awk '{for(i=1;i<4;i++) $i="";print}' file

How can I disable editing cells in a WPF Datagrid?

The DataGrid has an XAML property IsReadOnly that you can set to true:


Failed to load JavaHL Library

You may or may not need JavaHL depending on your OS. In addition to other suggestions just posting this here.

enter image description here

For other OS see this source:

ng-options with simple array init

you could use something like

<select ng-model="myselect">
    <option ng-repeat="o in options" ng-selected="{{o==myselect}}" value="{{o}}">

using ng-selected you preselect the option in case myselect was prefilled.

I prefer this method over ng-options anyway, as ng-options only works with arrays. ng-repeat also works with json-like objects.

Android Error Building Signed APK: keystore.jks not found for signing config 'externalOverride'

I have same problem, because i don't have keystore path then i see solutions and had a new problem In my Android Studio 3.1 for mac had a windows dialog problem when trying create new keystore path, it's like this

enter image description here

if u have the same problem, don't worried about the black windows it's just typing your new keystore and then save.

How to Initialize char array from a string

You can't - in C. In C initializing of global and local static variables are designed such that the compiler can put the values statically into the executable. It can't handle non-constant expressions as initializers. And only in C99, you can use non-constant expression in aggregate initializers - not so in C89!

In your case, since your array is an array containing characters, each element has to be an arithmetic constant expression. Look what it says about those

An arithmetic constant expression shall have arithmetic type and shall only have operands that are integer constants, ?oating constants, enumeration constants, character constants, and sizeof expressions.

Surely this is not satisfied by your initializer, which uses an operand of pointer type. Surely, the other way is to initialize your array using a string literal, as it explains too

All the expressions in an initializer for an object that has static storage duration shall be constant expressions or string literals.

All quotes are taken out of the C99 TC3 committee draft. So to conclude, what you want to do - using non-constant expression - can't be done with C. You have several options:

  • Write your stuff multiple times - one time reversed, and the other time not reversed.
  • Change the language - C++ can do that all.
  • If you really want to do that stuff, use an array of char const* instead

Here is what i mean by the last option

char const c[] = "ABCD";
char const *f[] = { &c[0], &c[1], &c[2], &c[3] };
char const *g[] = { &c[3], &c[2], &c[1], &c[0] };

That works fine, as an address constant expression is used to initialize the pointers

An address constant is a null pointer, a pointer to an lvalue designating an object of static storage duration, or a pointer to a function designator; it shall be created explicitly using the unary & operator or an integer constant cast to pointer type, or implicitly by the use of an expression of array or function type. The array-subscript [] and member-access . and -> operators, the address & and indirection * unary operators, and pointer casts may be used in the creation of an address constant, but the value of an object shall not be accessed by use of these operators.

You may have luck tweaking your compiler options - another quote:

An implementation may accept other forms of constant expressions.

What are the differences between Visual Studio Code and Visual Studio?

Complementing the previous answers, one big difference between both is that Visual Studio Code comes in a so called "portable" version that does not require full administrative permissions to run on Windows and can be placed in a removable drive for convenience.

How can I maintain fragment state when added to the back stack?

If you return to a fragment from the back stack it does not re-create the fragment but re-uses the same instance and starts with onCreateView() in the fragment lifecycle, see Fragment lifecycle.

So if you want to store state you should use instance variables and not rely on onSaveInstanceState().

jquery: how to get the value of id attribute?

You need to do:


How to verify Facebook access token?

I found this official tool from facebook developer page, this page will you following information related to access token - App ID, Type, App-Scoped,User last installed this app via, Issued, Expires, Data Access Expires, Valid, Origin, Scopes. Just need access token.

SQL Server: use CASE with LIKE

You can also do like this

select *
from table
where columnName like '%' + case when @varColumn is null then '' else @varColumn end  +  ' %'

How to get current relative directory of your Makefile?

Example for your reference, as below:

The folder structure might be as:

enter image description here

Where there are two Makefiles, each as below;


Now, let us see the content of the Makefiles.


export ROOT_DIR=${PWD}

    echo ${ROOT_DIR}
    $(MAKE) -C test


    echo ${ROOT_DIR}
    echo "make test ends here !"

Now, execute the sample/Makefile, as;

cd sample


echo /home/symphony/sample
make -C test
make[1]: Entering directory `/home/symphony/sample/test'
echo /home/symphony/sample
echo "make test ends here !"
make test ends here !
make[1]: Leaving directory `/home/symphony/sample/test'

Explanation, would be that the parent/home directory can be stored in the environment-flag, and can be exported, so that it can be used in all the sub-directory makefiles.

Pass array to where in Codeigniter Active Record

From the Active Record docs:


Generates a WHERE field IN ('item', 'item') SQL query joined with AND if appropriate

$names = array('Frank', 'Todd', 'James');
$this->db->where_in('username', $names);
// Produces: WHERE username IN ('Frank', 'Todd', 'James')

Export to CSV using jQuery and html

 <a id="export" role='button'>
        Click Here To Download Below Report
    <table id="testbed_results" style="table-layout:fixed">
            <tr width="100%" style="color:white" bgcolor="#3195A9" id="tblHeader">
                <th>COmpany result</th>
            <tr id="samplerow">

    $(document).ready(function () {
        Html2CSV('testbed_results', 'myfilename','export');

    function Html2CSV(tableId, filename,alinkButtonId) {
        var array = [];
        var headers = [];
        var arrayItem = [];
        var csvData = new Array();
        $('#' + tableId + ' th').each(function (index, item) {
            headers[index] = '"' + $(item).html() + '"';
        $('#' + tableId + ' tr').has('td').each(function () {

            $('td', $(this)).each(function (index, item) {
                arrayItem[index] = '"' + $(item).html() + '"';

        var fileName = filename + '.csv';
        var buffer = csvData.join("\n");
        var blob = new Blob([buffer], {
            "type": "text/csv;charset=utf8;"
        var link = document.getElementById(alinkButton);

        if ( !== undefined) { // feature detection
            // Browsers that support HTML5 download attribute
            link.setAttribute("href", window.URL.createObjectURL(blob));
            link.setAttribute("download", fileName);
        else if (navigator.msSaveBlob) { // IE 10+
            link.setAttribute("href", "#");
            link.addEventListener("click", function (event) {
                navigator.msSaveBlob(blob, fileName);
            }, false);
        else {
            // it needs to implement server side export
            link.setAttribute("href", "");


How can I convince IE to simply display application/json rather than offer to download it?

If you are okay with just having IE open the JSON into a notepad, you can change your system's default program for .json files to Notepad.

To do this, create or find a .json file, right mouse click, and select "Open With" or "Choose Default Program."

This might come in handy if you by chance want to use Internet Explorer but your IT company wont let you edit your registry. Otherwise, I recommend the above answers.

How to change the text of a button in jQuery?

    if (this.value=="Add") this.value = "Save";_x000D_
    else this.value = "Add";_x000D_
<!DOCTYPE html>_x000D_
<script src=""></script>_x000D_
<input type='button' value='Add' id='btnAddProfile'>_x000D_
<p>This is a paragraph with little content.</p>_x000D_
<p>This is another small paragraph.</p>_x000D_

Inverse dictionary lookup in Python

No, you can not do this efficiently without looking in all the keys and checking all their values. So you will need O(n) time to do this. If you need to do a lot of such lookups you will need to do this efficiently by constructing a reversed dictionary (can be done also in O(n)) and then making a search inside of this reversed dictionary (each search will take on average O(1)).

Here is an example of how to construct a reversed dictionary (which will be able to do one to many mapping) from a normal dictionary:

for i in h_normal:
    for j in h_normal[i]:
        if j not in h_reversed:
            h_reversed[j] = set([i])

For example if your

h_normal = {
  1: set([3]), 
  2: set([5, 7]), 
  3: set([]), 
  4: set([7]), 
  5: set([1, 4]), 
  6: set([1, 7]), 
  7: set([1]), 
  8: set([2, 5, 6])

your h_reversed will be

  1: set([5, 6, 7]),
  2: set([8]), 
  3: set([1]), 
  4: set([5]), 
  5: set([8, 2]), 
  6: set([8]), 
  7: set([2, 4, 6])

How do we download a blob url video

I just came up with a general solution, which should work on most websites. I tried this on Chrome only, but this method should work with any other browser, though, as Dev Tools are pretty much the same in them all.


  1. Open the browser's Dev Tools (usually F12, or Ctrl-Shift-I, or right-click and then Inspect in the popup menu) on the page with the video you are interested in.
  2. Go to Network tab and then reload the page. The tab will get populated with a list of requests (may be up to a hundred of them or even more).
  3. Search through the names of requests and find the request with .m3u8 extension. There may be many of them, but most likely the first you find is the one you are looking for. It may have any name, e.g. playlist.m3u8.
  4. Open the request and under Headers subsection you will see request's full URL in Request URL field. Copy it. enter image description here
  5. Extract the video from m3u8. There are many ways to do it, I'll give you those I tried, but you can google more by "download video from m3u8".
    • Option 1. If you have VLC player installed, feed the URL to VLC using "Open Network Stream..." menu option. I'm not going to go into details on this part here, there are a number of comprehensive guides in many places, for example, here. If the page doesn't work, you can always google another one by "vlc download online video".
    • Option 2. If you are more into command line, use FFMPEG or your own script, as directed in this SuperUser question.

What is ANSI format?

When using single-byte characters, the ASCII format defines the first 127 characters. The extended characters from 128-255 are defined by various ANSI code pages to allow limited support for other languages. In order to make sense of an ANSI encoded string, you need to know which code page it uses.

Declare a Range relative to the Active Cell with VBA

Like this:

Dim rng as Range
Set rng = ActiveCell.Resize(numRows, numCols)

then read the contents of that range to an array:

Dim arr As Variant
arr = rng.Value
'arr is now a two-dimensional array of size (numRows, numCols)

or, select the range (I don't think that's what you really want, but you ask for this in the question).


How do I increase the cell width of the Jupyter/ipython notebook in my browser?

I made some modification to @jvd10's solution. The '!important' seems too strong that the container doesn't adapt well when TOC sidebar is displayed. I removed it and added 'min-width' to limit the minimal width.

Here is my .juyputer/custom/custom.css:

/* Make the notebook cells take almost all available width and limit minimal width to 1110px */
.container {
    width: 99%;
    min-width: 1110px;

/* Prevent the edit cell highlight box from getting clipped;
 * important so that it also works when cell is in edit mode*/
div.cell.selected {
    border-left-width: 1px;

How to Correctly handle Weak Self in Swift Blocks with Arguments

Swift 4.2

let closure = { [weak self] (_ parameter:Int) in
    guard let self = self else { return }


Is there a list of screen resolutions for all Android based phones and tablets?

Google recently added this comprehensive list of reference devices and resolutions, including new device types such as wearables and laptops:

Python: How to keep repeating a program until a specific input is obtained?

you probably want to use a separate value that tracks if the input is valid:

good_input = None
while not good_input:
     user_input = raw_input("enter the right letter : ")
     if user_input in list_of_good_values: 
        good_input = user_input

Removing the textarea border in HTML

Add this to your <head>:

<style type="text/css">
    textarea { border: none; }

Or do it directly on the textarea:

<textarea style="border: none"></textarea>

When using .net MVC RadioButtonFor(), how do you group so only one selection can be made?

In cases where the name attribute is different it is easiest to control the radio group via JQuery. When an option is selected use JQuery to un-select the other options.

Difference between webdriver.Dispose(), .Close() and .Quit()

close() is a webdriver command which closes the browser window which is currently in focus. Despite the familiar name for this method, WebDriver does not implement the AutoCloseable interface.

During the automation process, if there are more than one browser window opened, then the close() command will close only the current browser window which is having focus at that time. The remaining browser windows will not be closed. The following code can be used to close the current browser window:

quit() is a webdriver command which calls the driver.dispose method, which in turn closes all the browser windows and terminates the WebDriver session. If we do not use quit() at the end of program, the WebDriver session will not be closed properly and the files will not be cleared off memory. This may result in memory leak errors.

If the Automation process opens only a single browser window, the close() and quit() commands work in the same way. Both will differ in their functionality when there are more than one browser window opened during Automation.

For Above Ref : click here

Dispose Command Dispose() should call Quit(), and it appears it does. However, it also has the same problem in that any subsequent actions are blocked until PhantomJS is manually closed.

Ref Link

Why is Spring's ApplicationContext.getBean considered bad?

One of the reasons is testability. Say you have this class:

interface HttpLoader {
    String load(String url);
interface StringOutput {
    void print(String txt);
class MyBean {
    MyBean(HttpLoader loader, StringOutput out) {

How can you test this bean? E.g. like this:

class MyBeanTest {
    public void creatingMyBean_writesStackoverflowPageToOutput() {
        // setup
        String stackOverflowHtml = "dummy";
        StringBuilder result = new StringBuilder();

        // execution
        new MyBean(Collections.singletonMap("", stackOverflowHtml)::get, result::append);

        // evaluation
        assertEquals(result.toString(), stackOverflowHtml);

Easy, right?

While you still depend on Spring (due to the annotations) you can remove you dependency on spring without changing any code (only the annotation definitions) and the test developer does not need to know anything about how spring works (maybe he should anyway, but it allows to review and test the code separately from what spring does).

It is still possible to do the same when using the ApplicationContext. However then you need to mock ApplicationContext which is a huge interface. You either need a dummy implementation or you can use a mocking framework such as Mockito:

class MyBean {
    MyBean(ApplicationContext context) {
        HttpLoader loader = context.getBean(HttpLoader.class);
        StringOutput out = context.getBean(StringOutput.class);

class MyBeanTest {
    public void creatingMyBean_writesStackoverflowPageToOutput() {
        // setup
        String stackOverflowHtml = "dummy";
        StringBuilder result = new StringBuilder();
        ApplicationContext context = Mockito.mock(ApplicationContext.class);
            .thenReturn(Collections.singletonMap("", stackOverflowHtml)::get);

        // execution
        new MyBean(context);

        // evaluation
        assertEquals(result.toString(), stackOverflowHtml);

This is quite a possibility, but I think most people would agree that the first option is more elegant and makes the test simpler.

The only option that is really a problem is this one:

class MyBean {
    MyBean(StringOutput out) {
        out.print(new HttpLoader().load(""));

Testing this requires huge efforts or your bean is going to attempt to connect to stackoverflow on each test. And as soon as you have a network failure (or the admins at stackoverflow block you due to excessive access rate) you will have randomly failing tests.

So as a conclusion I would not say that using the ApplicationContext directly is automatically wrong and should be avoided at all costs. However if there are better options (and there are in most cases), then use the better options.

Skip first line(field) in loop using CSV file? Return the next row of the reader’s iterable object as a list, parsed according to the current dialect.

Select distinct values from a table field

In addition to the still very relevant answer of jujule, I find it quite important to also be aware of the implications of order_by() on distinct("field_name") queries. This is, however, a Postgres only feature!

If you are using Postgres and if you define a field name that the query should be distinct for, then order_by() needs to begin with the same field name (or field names) in the same sequence (there may be more fields afterward).


When you specify field names, you must provide an order_by() in the QuerySet, and the fields in order_by() must start with the fields in distinct(), in the same order.

For example, SELECT DISTINCT ON (a) gives you the first row for each value in column a. If you don’t specify an order, you’ll get some arbitrary row.

If you want to e-g- extract a list of cities that you know shops in , the example of jujule would have to be adapted to this:

# returns an iterable Queryset of cities.
models.Shop.objects.order_by('city').values_list('city', flat=True).distinct('city')  

Scroll back to the top of scrollable div

If you want to scroll with a smooth transition, you could use this!

(Vanilla JS)

const tabScroll = document.getElementById("tabScroll");
  'behavior': 'smooth',
  'left': 0,
  'top': tabScroll.offsetTop - 80

If your target users are Chrome and Firefox, then this is good! But unfortunately this method isn’t supported well enough on all browsers. Check Here

Hope this helps!!

Why am I getting string does not name a type Error?

Your using declaration is in game.cpp, not game.h where you actually declare string variables. You intended to put using namespace std; into the header, above the lines that use string, which would let those lines find the string type defined in the std namespace.

As others have pointed out, this is not good practice in headers -- everyone who includes that header will also involuntarily hit the using line and import std into their namespace; the right solution is to change those lines to use std::string instead

How to use Comparator in Java to sort

Here is my answer for a simple comparator tool

public class Comparator {
public boolean isComparatorRunning  = false;
public void compareTableColumns(List<String> tableNames) {
    if(!isComparatorRunning) {
        isComparatorRunning = true;
        try {
            for (String schTableName : tableNames) {
                Map<String, String> schemaTableMap = ComparatorUtil.getSchemaTableMap(schTableName); 
                Map<String, ColumnInfo> primaryColMap = ComparatorUtil.getColumnMetadataMap(DbConnectionRepository.getConnectionOne(), schemaTableMap);
                Map<String, ColumnInfo> secondaryColMap = ComparatorUtil.getColumnMetadataMap(DbConnectionRepository.getConnectionTwo(), schemaTableMap);
                ComparatorUtil.publishColumnInfoOutput("Comparing table : "+ schemaTableMap.get(CompConstants.TABLE_NAME));
                compareColumns(primaryColMap, secondaryColMap);
        } catch (Exception e) {
        isComparatorRunning = false;

public void compareColumns(Map<String, ColumnInfo> primaryColMap, Map<String, ColumnInfo> secondaryColMap) {
    try {
        boolean isEqual = true;
        for(Map.Entry<String, ColumnInfo> entry : primaryColMap.entrySet()) {
            String columnName = entry.getKey();
            ColumnInfo primaryColInfo = entry.getValue();
            ColumnInfo secondaryColInfo = secondaryColMap.remove(columnName);
            if(secondaryColInfo == null) {
                // column is not present in Secondary Environment
                ComparatorUtil.publishColumnInfoOutput("ALTER", primaryColInfo);
                isEqual = false;
            if(!primaryColInfo.equals(secondaryColInfo)) {
                isEqual = false;
                // Column not equal in secondary env
                ComparatorUtil.publishColumnInfoOutput("MODIFY", primaryColInfo);
        if(!secondaryColMap.isEmpty()) {
            isEqual = false;
            for(Map.Entry<String, ColumnInfo> entry : secondaryColMap.entrySet()) {
                // column is not present in Primary Environment
                ComparatorUtil.publishColumnInfoOutput("DROP", entry.getValue());

        if(isEqual) {
            ComparatorUtil.publishColumnInfoOutput("--Exact Match");
    } catch (Exception e) {

public void compareTableColumnsValues(String primaryTableName, String primaryColumnNames, String primaryCondition, String primaryKeyColumn, 
        String secTableName, String secColumnNames, String secCondition, String secKeyColumn) {
    if(!isComparatorRunning) {
        isComparatorRunning = true;
        Connection conn1 = DbConnectionRepository.getConnectionOne();
        Connection conn2 = DbConnectionRepository.getConnectionTwo();

        String query1 = buildQuery(primaryTableName, primaryColumnNames, primaryCondition, primaryKeyColumn);
        String query2 = buildQuery(secTableName, secColumnNames, secCondition, secKeyColumn);
        try {
            Map<String,Map<String, Object>> query1Data = executeAndRefactorData(conn1, query1, primaryKeyColumn);
            Map<String,Map<String, Object>> query2Data = executeAndRefactorData(conn2, query2, secKeyColumn);

            for(Map.Entry<String,Map<String, Object>> entry : query1Data.entrySet()) {
                String key = entry.getKey();
                Map<String, Object> value = entry.getValue();
                Map<String, Object> secondaryValue = query2Data.remove(key);
                if(secondaryValue == null) {
                    ComparatorUtil.publishColumnValuesInfoOutput("NO SUCH VALUE AVAILABLE IN SECONDARY DB "+ value.toString());
                compareMap(value, secondaryValue, key);

            if(!query2Data.isEmpty()) {
                ComparatorUtil.publishColumnValuesInfoOutput("Extra Values in Secondary table "+ ((Map)query2Data.values()).values().toString());
        } catch (Exception e) {
        isComparatorRunning = false;

private void compareMap(Map<String, Object> primaryValues, Map<String, Object> secondaryValues, String columnIdentification) {
    for(Map.Entry<String, Object> entry : primaryValues.entrySet()) {
        String key = entry.getKey();
        Object value = entry.getValue();
        Object secValue = secondaryValues.get(key);
        if(value!=null && secValue!=null && !String.valueOf(value).equalsIgnoreCase(String.valueOf(secValue))) {
            ComparatorUtil.publishColumnValuesInfoOutput(columnIdentification+" : Secondary Table does not match value ("+ value +") for column ("+ key+")");
        if(value==null && secValue!=null) {
            ComparatorUtil.publishColumnValuesInfoOutput(columnIdentification+" : Values not available in primary table for column "+ key);
        if(value!=null && secValue==null) {
            ComparatorUtil.publishColumnValuesInfoOutput(columnIdentification+" : Values not available in Secondary table for column "+ key);

private String buildQuery(String tableName, String column, String condition, String keyCol) {
    if(!"*".equalsIgnoreCase(column)) {
        String[] keyColArr = keyCol.split(",");
        for(String key: keyColArr) {
            if(!column.contains(key.trim())) {
    StringBuilder queryBuilder = new StringBuilder();
    queryBuilder.append("select "+column+" from "+ tableName);
    if(!ComparatorUtil.isNullorEmpty(condition)) {
        queryBuilder.append(" where 1=1 and "+condition);
    return queryBuilder.toString();

private Map<String,Map<String, Object>> executeAndRefactorData(Connection connection, String query, String keyColumn) {
    Map<String,Map<String, Object>> result = new HashMap<String, Map<String,Object>>();
    try {
        PreparedStatement preparedStatement = connection.prepareStatement(query);
        ResultSet resultSet = preparedStatement.executeQuery();
        if (resultSet != null && !resultSet.isClosed()) {
            while ( {
                Map<String, Object> columnValueDetails = new HashMap<String, Object>();
                int columnCount = resultSet.getMetaData().getColumnCount();
                for (int i=1; i<=columnCount; i++) {
                    String columnName = String.valueOf(resultSet.getMetaData().getColumnName(i));
                    Object columnValue = resultSet.getObject(columnName);
                    columnValueDetails.put(columnName, columnValue);
                String[] keys = keyColumn.split(",");
                String newKey = "";
                for(int j=0; j<keys.length; j++) {
                    newKey += String.valueOf(columnValueDetails.get(keys[j]));
                result.put(newKey , columnValueDetails);

    } catch (SQLException e) {
    return result;


Utility Tool for the same

public class ComparatorUtil {

public static Map<String, String> getSchemaTableMap(String tableNameWithSchema) {
    if(isNullorEmpty(tableNameWithSchema)) {
        return null;
    Map<String, String> result = new LinkedHashMap<>();
    int index = tableNameWithSchema.indexOf(".");
    String schemaName = tableNameWithSchema.substring(0, index);
    String tableName = tableNameWithSchema.substring(index+1);
    result.put(CompConstants.SCHEMA_NAME, schemaName);
    result.put(CompConstants.TABLE_NAME, tableName);
    return result;

public static Map<String, ColumnInfo> getColumnMetadataMap(Connection conn, Map<String, String> schemaTableMap) {
    try {
        String schemaName = schemaTableMap.get(CompConstants.SCHEMA_NAME);
        String tableName = schemaTableMap.get(CompConstants.TABLE_NAME);
        ResultSet resultSetConnOne = conn.getMetaData().getColumns(null, schemaName, tableName, null);
        Map<String, ColumnInfo> resultSetTwoColInfo = getColumnInfo(schemaName, tableName, resultSetConnOne);
        return resultSetTwoColInfo;
    } catch (SQLException e) {
    return null;

/* Number Type mapping
 * 12-----VARCHAR
 * 3-----DECIMAL
 * 93-----TIMESTAMP
 * 1111-----OTHER
public static Map<String, ColumnInfo> getColumnInfo(String schemaName, String tableName, ResultSet columns) {
    try {
        Map<String, ColumnInfo> tableColumnInfo = new LinkedHashMap<String, ColumnInfo>();
        while ( {
            ColumnInfo columnInfo = new ColumnInfo();
            tableColumnInfo.put(columnInfo.getColumnName(), columnInfo);
        return tableColumnInfo;
    } catch (Exception e) {
    return null;

public static boolean isNullOrEmpty(Object obj) {
    if (obj == null)
        return true;
    if (String.valueOf(obj).equalsIgnoreCase("NULL")) 
        return true;
    if (obj.toString().trim().length() == 0)
        return true;
    return false;

public static boolean isNullorEmpty(String str) {
    if(str == null)
        return true;
    if(str.trim().length() == 0) 
        return true;
    return false;

public static void publishColumnInfoOutput(String type, ColumnInfo columnInfo) {
    String str = "ALTER TABLE "+columnInfo.getSchemaName()+"."+columnInfo.getTableName();
    switch(type.toUpperCase()) {
        case "ALTER":
            if("NUMBER".equalsIgnoreCase(columnInfo.getDatatype()) || "DATE".equalsIgnoreCase(columnInfo.getDatatype())) {
                str += " ADD ("+columnInfo.getColumnName()+" "+ columnInfo.getDatatype()+");";
            } else {
                str += " ADD ("+columnInfo.getColumnName()+" "+ columnInfo.getDatatype() +"("+columnInfo.getColumnsize()+"));";
        case "DROP":
            str += " DROP ("+columnInfo.getColumnName()+");";
        case "MODIFY":
            if("NUMBER".equalsIgnoreCase(columnInfo.getDatatype()) || "DATE".equalsIgnoreCase(columnInfo.getDatatype())) {
                str += " MODIFY ("+columnInfo.getColumnName()+" "+ columnInfo.getDatatype()+");";
            } else {
                str += " MODIFY ("+columnInfo.getColumnName()+" "+ columnInfo.getDatatype() +"("+columnInfo.getColumnsize()+"));";

public static Map<Integer, String> allJdbcTypeName = null;

public static Map<Integer, String> getAllJdbcTypeNames() {
    Map<Integer, String> result = new HashMap<Integer, String>();
    if(allJdbcTypeName != null)
        return allJdbcTypeName;
    try {
        for (Field field : java.sql.Types.class.getFields()) {
            result.put((Integer) field.get(null), field.getName());
    } catch (Exception e) {
    return allJdbcTypeName=result;

public static String getStringPlaces(String[] attribs) {
    String params = "";
    for(int i=0; i<attribs.length; i++) { params += "?,"; }
    return params.substring(0, params.length()-1);


Column Info Class

public class ColumnInfo {
private String schemaName;
private String tableName;
private String columnName;
private String datatype;
private String columnsize;
private String decimaldigits;
private String isNullable;

How to remove rows with any zero value

I would probably go with Joran's suggestion of replacing 0's with NAs and then using the built in functions you mentioned. If you can't/don't want to do that, one approach is to use any() to find rows that contain 0's and subset those out:

#Fake data
x <- data.frame(a = sample(0:2, 5, TRUE), b = sample(0:2, 5, TRUE))
> x
  a b
1 2 1
2 2 2
3 0 0
4 2 1
5 1 2
#Subset out any rows with a 0 in them
#Note the negation with ! around the apply function
x[!(apply(x, 1, function(y) any(y == 0))),]
  a b
1 2 1
2 2 2
4 2 1
5 1 2

To implement Joran's method, something like this should get you started:

x[x==0] <- NA

Travel/Hotel API's?

You could probably trying using Yahoo or Google's APIs. They are generic, but by specifying the right set of parameters, you could probably narrow down the results to just hotels. Check out Yahoo's Local Search API and Google's Local Search API

How do I parse a YAML file in Ruby?

Maybe I'm missing something, but why try to parse the file? Why not just load the YAML and examine the object(s) that result?

If your sample YAML is in some.yml, then this:

require 'yaml'
thing = YAML.load_file('some.yml')
puts thing.inspect

gives me

{"javascripts"=>[{"fo_global"=>["lazyload-min", "holla-min"]}]}

Explicitly calling return in a function or not

I think of return as a trick. As a general rule, the value of the last expression evaluated in a function becomes the function's value -- and this general pattern is found in many places. All of the following evaluate to 3:



(function() {

What return does is not really returning a value (this is done with or without it) but "breaking out" of the function in an irregular way. In that sense, it is the closest equivalent of GOTO statement in R (there are also break and next). I use return very rarely and never at the end of a function.

 if(a) {
 } else {

... this can be rewritten as if(a) a else b which is much better readable and less curly-bracketish. No need for return at all here. My prototypical case of use of "return" would be something like ...

ugly <- function(species, x, y){
   if(length(species)>1) stop("First argument is too long.")
   if(species=="Mickey Mouse") return("You're kidding!")
   ### do some calculations 
   if(grepl("mouse", species)) {
      ## do some more calculations
      if(species=="Dormouse") return(paste0("You're sleeping until", x+y))
      ## do some more calculations
      return(paste0("You're a mouse and will be eating for ", x^y, " more minutes."))
   ## some more ugly conditions
   # ...
   ### finally
   return("The end")

Generally, the need for many return's suggests that the problem is either ugly or badly structured.


return doesn't really need a function to work: you can use it to break out of a set of expressions to be evaluated.

getout <- TRUE 
# if getout==TRUE then the value of EXP, LOC, and FUN will be "OUTTA HERE"
# .... if getout==FALSE then it will be `3` for all these variables    

EXP <- eval(expression({
   if(getout) return("OUTTA HERE")

LOC <- local({
   if(getout) return("OUTTA HERE")

FUN <- (function(){
   if(getout) return("OUTTA HERE")


Insert the same fixed value into multiple rows

To update the content of existing rows use the UPDATE statement:

UPDATE table_name SET table_column = 'test';

Do I need to pass the full path of a file in another directory to open()?

If you are just looking for the files in a single directory (ie you are not trying to traverse a directory tree, which it doesn't look like), why not simply use os.listdir():

import os  
for fn in os.listdir('.'):
     if os.path.isfile(fn):
        print (fn)

in place of os.walk(). You can specify a directory path as a parameter for os.listdir(). os.path.isfile() will determine if the given filename is for a file.

Why Git is not allowing me to commit even after configuration?

You're setting the global git options, but the local checkout possibly has overrides set. Try setting them again with git config --local <setting> <value>. You can look at the .git/config file in your local checkout to see what local settings the checkout has defined.

Change auto increment starting number?

How to auto increment by one, starting at 10 in MySQL:

create table foobar(
  moobar         VARCHAR(500)

INSERT INTO foobar(moobar) values ("abc");
INSERT INTO foobar(moobar) values ("def");
INSERT INTO foobar(moobar) values ("xyz");

select * from foobar;

'10', 'abc'
'11', 'def'
'12', 'xyz'

This auto increments the id column by one starting at 10.

Auto increment in MySQL by 5, starting at 10:

drop table foobar
create table foobar(
  moobar         VARCHAR(500)
SET @@auto_increment_increment=5;

INSERT INTO foobar(moobar) values ("abc");
INSERT INTO foobar(moobar) values ("def");
INSERT INTO foobar(moobar) values ("xyz");

select * from foobar;
'11', 'abc'
'16', 'def'
'21', 'xyz'

This auto increments the id column by 5 each time, starting at 10.

React "after render" code?

One drawback of using componentDidUpdate, or componentDidMount is that they are actually executed before the dom elements are done being drawn, but after they've been passed from React to the browser's DOM.

Say for example if you needed set node.scrollHeight to the rendered node.scrollTop, then React's DOM elements may not be enough. You need to wait until the elements are done being painted to get their height.


Use requestAnimationFrame to ensure that your code is run after the painting of your newly rendered object

scrollElement: function() {
  // Store a 'this' ref, and
  var _this = this;
  // wait for a paint before running scrollHeight dependent code.
  window.requestAnimationFrame(function() {
    var node = _this.getDOMNode();
    if (node !== undefined) {
      node.scrollTop = node.scrollHeight;
componentDidMount: function() {
// and or
componentDidUpdate: function() {
// and or
render: function() {
  return [...]

How do I use a third-party DLL file in Visual Studio C++?

You only need to use LoadLibrary if you want to late bind and only resolve the imported functions at runtime. The easiest way to use a third party dll is to link against a .lib.

In reply to your edit:

Yes, the third party API should consist of a dll and/or a lib that contain the implementation and header files that declares the required types. You need to know the type definitions whichever method you use - for LoadLibrary you'll need to define function pointers, so you could just as easily write your own header file instead. Basically, you only need to use LoadLibrary if you want late binding. One valid reason for this would be if you aren't sure if the dll will be available on the target PC.

Readably print out a python dict() sorted by key

Another alternative :

>>> mydict = {'a':1, 'b':2, 'c':3}
>>> import json

Then with python2 :

>>> print json.dumps(mydict, indent=4, sort_keys=True) # python 2
    "a": 1, 
    "b": 2, 
    "c": 3

or with python 3 :

>>> print(json.dumps(mydict, indent=4, sort_keys=True)) # python 3
    "a": 1, 
    "b": 2, 
    "c": 3

HTML Image not displaying, while the src url works

It wont work since you use URL link with "file://". Instead you should match your directory to your HTML file, for example:

Lets say my file placed in:


And my wanted image is in:


All I have to do is matching the directory this way:

<img src="../project2/image.png" />

How to reshape data from long to wide format

Using reshape function:

reshape(dat1, idvar = "name", timevar = "numbers", direction = "wide")

Drop columns whose name contains a specific string from pandas DataFrame

import pandas as pd

import numpy as np


df=pd.DataFrame(array, columns=('Test1', 'toto', 'test2', 'riri'))

print df

      Test1      toto     test2      riri
0  0.923249  0.572528  0.845464  0.144891
1  0.020438  0.332540  0.144455  0.741412

cols = [c for c in df.columns if c.lower()[:4] != 'test']


print df
       toto      riri
0  0.572528  0.144891
1  0.332540  0.741412

The project type is not supported by this installation

Had the same issue with "The project type is not supported by this installation" for web projects in VS 2010 Premium.

devenv /ResetSkipPkgs

and GUIDs magic did not help.

Same projects were working fine on a neighbor box with VS 2010 Premium.

As it turned out the only difference was that my VS installation was missing the following installed products (can be found in VS About dialog):

  • Microsoft Office Developer Tools
  • Microsoft Visual Studio 2010 SharePoint Developer Tools

Add/Remove programs -> VS 2010 -> Customize -> Check the above products - and the problem was solved.

React Native: How to select the next TextInput after pressing the "next" keyboard button?

Using react-native 0.45.1 I also encountered problems trying to set focus on a password TextInput after pressing return key on a username TextInput.

After having tried most of the top rated solutions here on SO I found a solution on github that fulfilled my needs:

To sum it up:

import React, { Component } from 'react';
import { TextInput as RNTextInput } from 'react-native';

export default class TextInput extends Component {
    render() {
        const { props } = this;

        return (
                ref={(input) => props.inputRef && props.inputRef(input)}

And then I use it like this:

import React, {Component} from 'react';
import {
} from 'react-native';
import TextInput from "../../components/TextInput";

class Login extends Component {
    constructor(props) {
        this.passTextInput = null

    render() {
        return (
            <View style={{flex:1}}>
                    onSubmitEditing={(event) => {

                    inputRef={(input) => {
                        this.passTextInput = input

ASP.NET: HTTP Error 500.19 – Internal Server Error 0x8007000d

Install URL rewriting:

UPDATE - this is now available here (and works with IIS 7-10):

Ensure you have the following set to 'Allowed' for your IIS server:

enter image description here

Version of Apache installed on a Debian machine

Some installations of Apache are fubar (think Oracle's packaging of it, OHS) and do not understand the -V flag, nor can be invoked directly without running into missing library errors.

Easiest way is to use the strings command (part of binutils) on the httpd binary and grep for a string that might resemble a version. For example, assuming your httpd binary is under directory /foo/bar:

$ strings /foo/bar/httpd  | grep 2.2
Oracle-HTTP-Server/2.2.22 (Unix)
202 Accepted

Most binaries (not all) contain their version (at least their major version) as static strings. This is my go-to way to get versions (or to corroborate what a binary's help message matches what reality on the ground truly is.)

Output of git branch in tree like fashion

Tested on Ubuntu:

sudo apt install git-extras

This produces an effect similar to the 2 most upvoted answers here.


Also, if you have arcanist installed (correction: Uber's fork of arcanist installed--see the bottom of this answer here for installation instructions), arc flow shows a beautiful dependency tree of upstream dependencies (ie: which were set previously via arc flow new_branch or manually via git branch --set-upstream-to=upstream_branch).

Bonus git tricks:


  1. What's the difference between `arc graft` and `arc patch`?

How to break out from a ruby block?

next and break seem to do the correct thing in this simplified example!

class Bar
  def self.do_things
      Foo.some_method(1..10) do |x|
            next if x == 2
            break if x == 9
            print "#{x} "

class Foo
    def self.some_method(targets, &block)
      targets.each do |target|
          r = yield(target)
        rescue  => x
          puts "rescue #{x}"


output: 1 3 4 5 6 7 8

C++ Structure Initialization

After my question resulted in no satisfying result (because C++ doesn't implement tag-based init for structures), I took the trick I found here: Are members of a C++ struct initialized to 0 by default?

For you it would amount to do that:

address temp_address = {}; // will zero all fields in C++ = "Hamilton";
temp_address.prov = "Ontario";

This is certainly the closest to what you wanted originally (zero all the fields except those you want to initialize).

How can I correctly format currency using jquery?

As a corollary to why the jQuery FormatCurrency plugin is a good answer, I'd like to rebut your comment:

1. - Does not filter out all letter's. You can type a single letter and it will not remove it.

Yes, formatCurrency() by itself does not filter out letters:

// only formats currency

But toNumber(), included in the formatCurrency plugin, does.

You thus want to do:

// removes invalid characters, then formats currency

Google maps Places API V3 autocomplete - select first option on enter

I had the same issue when implementing autocomplete on a site I worked on recently. This is the solution I came up with:

$("input").focusin(function () {
    $(document).keypress(function (e) {
        if (e.which == 13) {
            var firstResult = $(".pac-container .pac-item:first").text();

            var geocoder = new google.maps.Geocoder();
            geocoder.geocode({"address":firstResult }, function(results, status) {
                if (status == google.maps.GeocoderStatus.OK) {
                    var lat = results[0],
                        lng = results[0].geometry.location.lng(),
                        placeName = results[0].address_components[0].long_name,
                        latlng = new google.maps.LatLng(lat, lng);

                        $(".pac-container .pac-item:first").addClass("pac-selected");

                    moveMarker(placeName, latlng);

        } else {


Java: get greatest common divisor

import scanner and instantiate scanner class;
declare your method with two parameters
declare a third variable;
set condition;
swap the parameter values if condition is met;
set second conditon based on result of first condition;
divide and assign remainder to the third variable;
swap the result;
in the main method, allow for user input;
Call the method;

public class gcf {
    public static void main (String[]args){//start of main method
        Scanner input = new Scanner (;//allow for user input
        System.out.println("Please enter the first integer: ");//prompt
        int a = input.nextInt();//initial user input
        System.out.println("Please enter a second interger: ");//prompt
        int b = input.nextInt();//second user input

       Divide(a,b);//call method
   public static void Divide(int a, int b) {//start of your method

    int temp;
    // making a greater than b
    if (b > a) {
         temp = a;
         a = b;
         b = temp;

    while (b !=0) {
        // gcd of b and a%b
        temp = a%b;
        // always make a greater than b
        a =b;
        b =temp;

    System.out.println(a);//print to console

Get folder up one level

The parent directory of an included file would be


e.g. the file is /var/www/html/folder/inc/ which is included in /var/www/html/folder/index.php

then by calling /file/index.php

getcwd() is /var/www/html/folder  
__DIR__ is /var/www/html/folder/inc  
so dirname(__DIR__) is /var/www/html/folder

but what we want is /var/www/html which is dirname(getcwd())

How to create websockets server in PHP

I've searched the minimal solution possible to do PHP + WebSockets during hours, until I found this article:

Super simple PHP WebSocket example

It doesn't require any third-party library.

Here is how to do it: create a index.html containing this:

    <div id="root"></div>
        var host = 'ws://<<<IP_OF_YOUR_SERVER>>>:12345/websockets.php';
        var socket = new WebSocket(host);
        socket.onmessage = function(e) {
            document.getElementById('root').innerHTML =;

and open it in the browser, just after you have launched php websockets.php in the command-line (yes, it will be an event loop, constantly running PHP script), with this websockets.php file.

In jQuery how can I set "top,left" properties of an element with position values relative to the parent and not the document?

Code offset dynamic for dynamic page

var pos=$('#send').offset().top;
$('#loading').offset({ top : pos-220});

Slide up/down effect with ng-show and ng-animate

This is actually pretty easy to do. All you have to do is change the css.

Here's a fiddle with a very simple fade animation:

To make it into a sliding animation, I first had to put my element in a box (that's the slide-container), then I added another element to replace the one that was leaving, just because I thought it would look nice. Take it out and the example will still work.

I changed the animation css from 'fade' to 'slide' but please note that these are the names I gave it. I could have written slide animation css named 'fade' or anything else for that matter.

The important part is what's in the css. Here's the original 'fade' css:

.fade-hide, .fade-show {
    -webkit-transition:all cubic-bezier(0.250, 0.460, 0.450, 0.940) 0.5s;
    -moz-transition:all cubic-bezier(0.250, 0.460, 0.450, 0.940) 0.5s;
    -o-transition:all cubic-bezier(0.250, 0.460, 0.450, 0.940) 0.5s;
    transition:all cubic-bezier(0.250, 0.460, 0.450, 0.940) 0.5s;
.fade-hide {
.fade-hide.fade-hide-active {
.fade-show {
.fade-show.fade-show-active {

This code changes the opacity of the element from 0 (completely transparent) to 1 (completely opaque) and back again. The solution is to leave opacity alone and instead change the top (or left, if you want to move left-right).

.slide-hide, .slide-show {
    -webkit-transition:all cubic-bezier(0.250, 0.460, 0.450, 0.940) 1.5s;
    -moz-transition:all cubic-bezier(0.250, 0.460, 0.450, 0.940) 1.5s;
    -o-transition:all cubic-bezier(0.250, 0.460, 0.450, 0.940) 1.5s;
    transition:all cubic-bezier(0.250, 0.460, 0.450, 0.940) 1.5s;
.slide-hide {
    position: relative;
    top: 0;
.slide-hide.slide-hide-active {
    position: absolute;
    top: -100px;
.slide-show {
    position: absolute;
    top: 100px;
.slide-show.slide-show-active {
    position: relative;
    top: 0px;

I'm also changing from relative to absolute positioning so only one of the elements takes up space in the container at a time.

Here's the finished product: Hope this helps!

How do I define a method in Razor?

You can also just use the @{ } block to create functions:

    async Task<string> MyAsyncString(string input)
        return Task.FromResult(input);

Then later in your razor page:

   <div>@(await MyAsyncString("weee").ConfigureAwait(false))</div>

"cannot be used as a function error"

Modify your estimated population function to take a growth argument of type float. Then you can call the growthRate function with your birthRate and deathRate and use the return value as the input for grown into estimatedPopulation.

float growthRate (float birthRate, float deathRate)     
    return ((birthRate) - (deathRate));    

int estimatedPopulation (int currentPopulation, float growth)
    return ((currentPopulation) + (currentPopulation) * (growth / 100);

// main.cpp
int currentPopulation = 100;
int births = 50;
int deaths = 25;
int population = estimatedPopulation(currentPopulation, growthRate(births, deaths));

set font size in jquery

You can try another way like that:

<div class="content">

jQuery code:

    background: "#d1d1d1",
    fontSize: "30px"

Now you can add more css property as you want.

Normalization in DOM parsing with java - how does it work?

In simple, Normalisation is Reduction of Redundancies.
Examples of Redundancies:
a) white spaces outside of the root/document tags(...<document></document>...)
b) white spaces within start tag (<...>) and end tag (</...>)
c) white spaces between attributes and their values (ie. spaces between key name and =")
d) superfluous namespace declarations
e) line breaks/white spaces in texts of attributes and tags
f) comments etc...

How do I alter the precision of a decimal column in Sql Server?

ALTER TABLE `tableName` CHANGE  `columnName` DECIMAL(16,1) NOT NULL;

I uses This for the alterration

Postgresql SELECT if string contains

I personally prefer the simpler syntax of the ~ operator.

SELECT id FROM TAG_TABLE WHERE 'aaaaaaaa' ~ tag_name;

Worth reading through Difference between LIKE and ~ in Postgres to understand the difference. `

Is there a MySQL option/feature to track history of changes to records?

Here is how we solved it

a Users table looked like this

id | name | address | phone | email | created_on | updated_on

And the business requirement changed and we were in a need to check all previous addresses and phone numbers a user ever had. new schema looks like this

Users (the data that won't change over time)
id | name

UserData (the data that can change over time and needs to be tracked)
id | id_user | revision | city | address | phone | email | created_on
 1 |   1     |    0     | NY   | lake st | 9809  | @long | 2015-10-24 10:24:20
 2 |   1     |    2     | Tokyo| lake st | 9809  | @long | 2015-10-24 10:24:20
 3 |   1     |    3     | Sdny | lake st | 9809  | @long | 2015-10-24 10:24:20
 4 |   2     |    0     | Ankr | lake st | 9809  | @long | 2015-10-24 10:24:20
 5 |   2     |    1     | Lond | lake st | 9809  | @long | 2015-10-24 10:24:20

To find the current address of any user, we search for UserData with revision DESC and LIMIT 1

To get the address of a user between a certain period of time we can use created_on bewteen (date1 , date 2)

How to limit the number of dropzone.js files uploaded?

I thought that the most intuitive single file upload process was to replace the previous file upon a new entry.

    url: '/cart?upload-engraving=true',
    maxFiles: 1,
    maxfilesexceeded: function(file) {

Concatenate a list of pandas dataframes together

If the dataframes DO NOT all have the same columns try the following:

df = pd.DataFrame.from_dict(map(dict,df_list))

How to validate Google reCAPTCHA v3 on server side?

To verify at server side using PHP. Two most important thing you need to consider.

1. $_POST['g-recaptcha-response']

2.$secretKey = '6LeycSQTAAAAAMM3AeG62pBslQZwBTwCbzeKt06V';

$verifydata = file_get_contents(''.$secretKey.'&response='.$_POST['g-recaptcha-response']);
        $response= json_decode($verifydata);

If you get $verifydata true, You done.
For more check out this
Google reCaptcha Using PHP | Only 2 Step Integration

How to reset a form using jQuery with .reset() method

Here is simple solution with Jquery. It works globally. Have a look on the code.

$('document').on("click", ".clear", function(){

Add a clear class to a button in every form you need to reset it. For example:

<button class="button clear" type="reset">Clear</button>

No provider for Http StaticInjectorError

I was trying to fix the issue for about an hour and just deiced to restart the server. Only to see the issue is fixed.

If you make changes to APP module and the issue remains the same, stop the server and try running the serve command again.

Using ionic 4 with angular 7

Remove duplicated rows using dplyr

Here is a solution using dplyr >= 0.5.

df <- data.frame(
  x = sample(0:1, 10, replace = T),
  y = sample(0:1, 10, replace = T),
  z = 1:10

> df %>% distinct(x, y, .keep_all = TRUE)
    x y z
  1 0 1 1
  2 1 0 2
  3 1 1 4

PostgreSQL: Resetting password of PostgreSQL on Ubuntu

Assuming you're the administrator of the machine, Ubuntu has granted you the right to sudo to run any command as any user.
Also assuming you did not restrict the rights in the pg_hba.conf file (in the /etc/postgresql/9.1/main directory), it should contain this line as the first rule:

# Database administrative login by Unix domain socket  
local   all             postgres                                peer

(About the file location: 9.1 is the major postgres version and main the name of your "cluster". It will differ if using a newer version of postgres or non-default names. Use the pg_lsclusters command to obtain this information for your version/system).

Anyway, if the pg_hba.conf file does not have that line, edit the file, add it, and reload the service with sudo service postgresql reload.

Then you should be able to log in with psql as the postgres superuser with this shell command:

sudo -u postgres psql

Once inside psql, issue the SQL command:

ALTER USER postgres PASSWORD 'newpassword';

In this command, postgres is the name of a superuser. If the user whose password is forgotten was ritesh, the command would be:

ALTER USER ritesh PASSWORD 'newpassword';

References: PostgreSQL 9.1.13 Documentation, Chapter 19. Client Authentication

Keep in mind that you need to type postgres with a single S at the end

If leaving the password in clear text in the history of commands or the server log is a problem, psql provides an interactive meta-command to avoid that, as an alternative to ALTER USER ... PASSWORD:

\password username

It asks for the password with a double blind input, then hashes it according to the password_encryption setting and issue the ALTER USER command to the server with the hashed version of the password, instead of the clear text version.

The multi-part identifier could not be bound

        phuongxa.maxa ,
        quanhuyen.mahuyen ,
        phuongxa.tenxa ,
        quanhuyen.tenhuyen ,
        ISNULL(dkcd.tong, 0) AS tongdkcd
FROM    phuongxa ,
        LEFT OUTER JOIN ( SELECT    khaosat.maxa ,
                                    COUNT(*) AS tong
                          FROM      khaosat
                          WHERE     CONVERT(DATETIME, ngaylap, 103) BETWEEN 'Sep 1 2011'
                                                              'Sep 5 2011'
                          GROUP BY  khaosat.maxa
                        ) AS dkcd ON dkcd.maxa = maxa
WHERE   phuongxa.maxa <> '99'
        AND LEFT(phuongxa.maxa, 2) = quanhuyen.mahuyen
ORDER BY maxa;

Adding default parameter value with type hint in Python

Your second way is correct.

def foo(opts: dict = {}):


this outputs

{'opts': <class 'dict'>}

It's true that's it's not listed in PEP 484, but type hints are an application of function annotations, which are documented in PEP 3107. The syntax section makes it clear that keyword arguments works with function annotations in this way.

I strongly advise against using mutable keyword arguments. More information here.

How to do Select All(*) in linq to sql

I often need to retrieve 'all' columns, except a few. so Select(x => x) does not work for me.

LINQPad's editor can auto-expand * to all columns.

enter image description here

after select '* all', LINQPad expands *, then I can remove not-needed columns.

enter image description here

Editing dictionary values in a foreach loop

Disclaimer: I don't do much C#

You are trying to modify the DictionaryEntry object which is stored in the HashTable. The Hashtable only stores one object -- your instance of DictionaryEntry. Changing the Key or the Value is enough to change the HashTable and cause the enumerator to become invalid.

You can do it outside of the loop:

    hashtable[key] = value;

by first creating a list of all the keys of the values you wish to change and iterate through that list instead.

What is the best way to remove a table row with jQuery?

If the row you want to delete might change you can use this. Just pass this function the row # you wish to delete.

function removeMyRow(docRowCount){
   $('table tr').eq(docRowCount).remove();

How to compile multiple java source files in command line

Here is another example, for compiling a java file in a nested directory.

I was trying to build this from the command line. This is an example from 'gradle', which has dependency 'commons-collection.jar'. For more info, please see 'gradle: java quickstart' example. -- of course, you would use the 'gradle' tools to build it. But i thought to extend this example, for a nested java project, with a dependent jar.

Note: You need the 'gradle binary or source' distribution for this, example code is in: 'samples/java/quickstart'

% mkdir -p temp/classes
% curl --get \ \
        --output commons-collections-3.2.2.jar

% javac -g -classpath commons-collections-3.2.2.jar \
     -sourcepath src/main/java -d temp/classes \

% jar cf my_example.jar -C temp/classes org/gradle/Person.class
% jar tvf my_example.jar
   0 Wed Jun 07 14:11:56 CEST 2017 META-INF/
  69 Wed Jun 07 14:11:56 CEST 2017 META-INF/MANIFEST.MF
 519 Wed Jun 07 13:58:06 CEST 2017 org/gradle/Person.class

jQuery Refresh/Reload Page if Ajax Success after time

I prefer this way Using ajaxStop + setInterval,, this will refresh the page after any XHR[ajax] request in the same page

    $(document).ajaxStop(function() {
        setInterval(function() {
        }, 3000);

How to make a JTable non-editable

You can use a TableModel.

Define a class like this:

public class MyModel extends AbstractTableModel{
    //not necessary

actually isCellEditable() is false by default so you may omit it. (see:

Then use the setModel() method of your JTable.

JTable myTable = new JTable();
myTable.setModel(new MyModel());

How to get class object's name as a string in Javascript?

This is pretty old, but I ran across this question via Google, so perhaps this solution might be useful to others.

function GetObjectName(myObject){
    var objectName=JSON.stringify(myObject).match(/"(.*?)"/)[1];
    return objectName;

It just uses the browser's JSON parser and regex without cluttering up the DOM or your object too much.

How to count instances of character in SQL Column

Try this:

SELECT COUNT(DECODE(SUBSTR(UPPER(:main_string),rownum,LENGTH(:search_char)),UPPER(:search_char),1)) search_char_count
connect by rownum <= length(:main_string);

It determines the number of single character occurrences as well as the sub-string occurrences in main string.

How does one output bold text in Bash?

In theory like so:

$ echo -e "\033[1mThis is a BOLD line\033[0m"
This is a BOLD line

# Using tput
tput bold 
echo "This" #BOLD
tput sgr0 #Reset text attributes to normal without clear.
echo "This" #NORMAL

$ echo -e "\033[4mThis is a underlined line.\033[0m"
This is a underlined line. 

But in practice it may be interpreted as "high intensity" color instead.


How to display a PDF via Android web browser without "downloading" first

Unfortunately the native browser present on Android devices not support this type of file. Let's see if in the 4.0 we will be able to do that.

Use formula in custom calculated field in Pivot Table

Some of it is possible, specifically accessing subtotals:

"In Excel 2010+, you can right-click on the values and select Show Values As –> % of Parent Row Total." (or % of Parent Column Total)

enter image description here

  • And make sure the field in question is a number field that can be summed, it does not work for text fields for which only count is normally informative.


How do I clear only a few specific objects from the workspace?

  1. In RStudio, ensure the Environment tab is in Grid (not List) mode.

  2. Tick the object(s) you want to remove from the environment.

  3. Click the broom icon.

Replace string in text file using PHP

Does this work:

$msgid = $_GET['msgid'];

$oldMessage = '';

$deletedFormat = '';

//read the entire string

//replace something in the file string - this is a VERY simple example
$str=str_replace($oldMessage, $deletedFormat,$str);

//write the entire string
file_put_contents('msghistory.txt', $str);

array filter in python?

set(A)-set(subset_of_A) gives your the intended result set, but it won't retain the original order. The following is order preserving:

[a for a in A if not a in subset_of_A]

The specified type member is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported

A lot of people are going to say this is a bad answer because it is not best practice but you can also convert it to a List before your where.

result = result.ToList().Where(p => date >= p.DOB);

Slauma's answer is better, but this would work as well. This cost more because ToList() will execute the Query against the database and move the results into memory.

Execute jar file with multiple classpath libraries from command prompt

Regardless of the OS the below command should work:

java -cp "MyJar.jar;lib/*" com.mainClass

Always use quotes and please take attention that lib/*.jar will not work.

How to load specific image from assets with Swift

Since swift 3.0 there is more convenient way: #imageLiterals here is text example. And below animated example from here:

enter image description here

What's a clean way to stop mongod on Mac OS X?

If you installed mongodb with homebrew, there's an easier way:

List mongo job with launchctl:

launchctl list | grep mongo

Stop mongo job:

launchctl stop <job label>

(For me this is launchctl stop homebrew.mxcl.mongodb)

Start mongo job:

launchctl start <job label>

Basic Apache commands for a local Windows machine

For frequent uses of this command I found it easy to add the location of C:\xampp\apache\bin to the PATH. Use whatever directory you have this installed in.

Then you can run from any directory in command line:

httpd -k restart

The answer above that suggests httpd -k -restart is actually a typo. You can see the commands by running httpd /?

TensorFlow: "Attempting to use uninitialized value" in variable initialization

run both:

Refresh page after form submitting

   <form method="post" action="">
   <tr><td><input name="Submit" type="submit" value="refresh"></td></tr>


Deactivate or remove the scrollbar on HTML

If you really need it...

html { overflow-y: hidden; }

Why use @Scripts.Render("~/bundles/jquery")

You can also use:

@Scripts.RenderFormat("<script type=\"text/javascript\" src=\"{0}\"></script>", "~/bundles/mybundle")

To specify the format of your output in a scenario where you need to use Charset, Type, etc.

Entity Framework code-first: migration fails with update-database, forces unneccessary(?) add-migration

Try this:

PM> Enable-migrations -force
PM> Add-migration MigrationName
PM> Update-database -force

Bootstrap footer at the bottom of the page

Use this stylesheet:

/* Sticky footer styles_x000D_
-------------------------------------------------- */_x000D_
html {_x000D_
  position: relative;_x000D_
  min-height: 100%;_x000D_
body {_x000D_
  /* Margin bottom by footer height */_x000D_
  margin-bottom: 60px;_x000D_
.footer {_x000D_
  position: absolute;_x000D_
  bottom: 0;_x000D_
  width: 100%;_x000D_
  /* Set the fixed height of the footer here */_x000D_
  height: 60px;_x000D_
  line-height: 60px; /* Vertically center the text there */_x000D_
  background-color: #f5f5f5;_x000D_
/* Custom page CSS_x000D_
-------------------------------------------------- */_x000D_
/* Not required for template or sticky footer method. */_x000D_
body > .container {_x000D_
  padding: 60px 15px 0;_x000D_
.footer > .container {_x000D_
  padding-right: 15px;_x000D_
  padding-left: 15px;_x000D_
code {_x000D_
  font-size: 80%;_x000D_

What is the difference between angular-route and angular-ui-router?

1- ngRoute is developed by angular team whereas ui-router is a 3rd party module. 2- ngRoute implements routing based on the route URL whereas ui-router implements routing based on the state of the application. 3- ui-router provides everything that the ng-route provides plus some additional features like nested states and multiple named views.

AngularJS - Access to child scope

Using $emit and $broadcast, (as mentioned by walv in the comments above)

To fire an event upwards (from child to parent)

$scope.$emit('myTestEvent', 'Data to send');

To fire an event downwards (from parent to child)

$scope.$broadcast('myTestEvent', {
  someProp: 'Sending you some data'

and finally to listen

$scope.$on('myTestEvent', function (event, data) {

For more details :-

Enjoy :)

Sending intent to BroadcastReceiver from adb

I had the same problem and found out that you have to escape spaces in the extra:

adb shell am broadcast -a com.whereismywifeserver.intent.TEST --es sms_body "test\ from\ adb"

So instead of "test from adb" it should be "test\ from\ adb"

unary operator expected in shell script when comparing null value with string

Since the value of $var is the empty string, this:

if [ $var == $var1 ]; then

expands to this:

if [ == abcd ]; then

which is a syntax error.

You need to quote the arguments:

if [ "$var" == "$var1" ]; then

You can also use = rather than ==; that's the original syntax, and it's a bit more portable.

If you're using bash, you can use the [[ syntax, which doesn't require the quotes:

if [[ $var = $var1 ]]; then

Even then, it doesn't hurt to quote the variable reference, and adding quotes:

if [[ "$var" = "$var1" ]]; then

might save a future reader a moment trying to remember whether [[ ... ]] requires them.

Datetime BETWEEN statement not working in SQL Server

Does the second query return any results from the 17th, or just from the 18th?

The first query will only return results from the 17th, or midnight on the 18th.

Try this instead

select * 
from LOGS 
where check_in >= CONVERT(datetime,'2013-10-17') 
and check_in< CONVERT(datetime,'2013-10-19')

Unable to Git-push master to Github - 'origin' does not appear to be a git repository / permission denied

One possibility that the above answers don't address is that you may not have an ssh access from your shell. That is, you may be in a network (some college networks do this) where ssh service is blocked.In that case you will not only be able to get github services but also any other ssh services. You can test if this is the problem by trying to use any other ssh service.This was the case with me.

Where to install Android SDK on Mac OS X?

brew install android-sdk --cask 

Change the Value of h1 Element within a Form with JavaScript

You can use this: document.getElementById('h1_id').innerHTML = 'the new text';

Post-increment and Pre-increment concept?

You should also be aware that the behaviour of postincrement/decrement operators is different in C/C++ and Java.


  int a=1;

in C/C++ the expression

 a++ + a++ + a++

evaluates to 3, while in Java it evaluates to 6. Guess why...

This example is even more confusing:

cout << a++ + a++ + a++ << "<->" << a++ + a++ ;

prints 9<->2 !! This is because the above expression is equivalent to:

    operator<<( cout, a++ + a++ ), 
  a++ + a++ + a++ 

TypeError: 'undefined' is not a function (evaluating '$(document)')

You can use both jQuery and $ in below snippet. it worked for me

jQuery( document ).ready(function( $ ) {
  // jQuery(document)
  // $(document)

c# .net change label text

you should convert test type >>>> test.tostring();

change the last line to this :

Label1.Text = "Du har nu lånat filmen:" + test.tostring();

Escape double quotes in parameter

I'm calling powershell from cmd, and passing quotes and neither escapes here worked. The grave accent worked to escape double quotes on this Win 10 surface pro.

>powershell.exe "echo la`"" >> test
>type test

Below are outputs I got for other characters to escape a double quote:


Using another quote to escape a quote resulted in no quotes. As you can see, the characters themselves got typed, but didn't escape the double quotes.

How to make the first option of <select> selected with jQuery

$('select#id').val($('#id option')[index].value)

Replace the id with particular select tag id and index with particular element you want to select.


<select class="input-field" multiple="multiple" id="ddlState" name="ddlState">
                                        <option value="AB">AB</option>
                                        <option value="AK">AK</option>
                                        <option value="AL">AL</option>

So here for first element selection I will use following code :

$('select#ddlState').val($('#ddlState option')[0].value)

What is the difference between :focus and :active?

Using "focus" will give keyboard users the same effect that mouse users get when they hover with a mouse. "Active" is needed to get the same effect in Internet Explorer.

The reality is, these states do not work as they should for all users. Not using all three selectors creates accessibility issues for many keyboard-only users who are physically unable to use a mouse. I invite you to take the #nomouse challenge (nomouse dot org).

Convert long/lat to pixel x/y on a given picture

One of the important things to take into account is the "zoom" level of your projection (for Google Maps in particular).

As Google explains it:

At zoom level 1, the map consists of 4 256x256 pixels tiles, resulting in a pixel space from 512x512. At zoom level 19, each x and y pixel on the map can be referenced using a value between 0 and 256 * 2^19

( See

To factor in the "zoom" value, I recommend the simple and effective deltaLonPerDeltaX and deltaLatPerDeltaY functions below. While x-pixels and longitudes are strictly proportional, this is not the case for y-pixels and latitudes, for which the formula requires the initial latitude.

// Adapted from :

window.geo = {

    glOffset: Math.pow(2,28), //268435456,
    glRadius:  Math.pow(2,28) / Math.PI,
    a: Math.pow(2,28),
    b: 85445659.4471,
    c: 0.017453292519943,
    d: 0.0000006705522537,
    e: Math.E, //2.7182818284590452353602875,
    p: Math.PI / 180,

    lonToX: function(lon) {
        return Math.round(this.glOffset + this.glRadius * lon * this.p);

    XtoLon: function(x) {
        return -180 + this.d * x;

    latToY: function(lat) {
        return Math.round(this.glOffset - this.glRadius *
                          Math.log((1 + Math.sin(lat * this.p)) /
                          (1 - Math.sin(lat * this.p))) / 2);

    YtoLat: function(y) {
        return Math.asin(Math.pow(this.e,(2*this.a/this.b - 2*y/this.b)) /
                                 (Math.pow(this.e, (2*this.a/this.b - 2*y/this.b))+1) -
                                 1/(Math.pow(this.e, (2*this.a/this.b - 2*y/this.b))+1)
                        ) / this.c;

    deltaLonPerDeltaX: function(deltaX, zoom) {
        // 2^(7+zoom) pixels <---> 180 degrees
        return deltaX * 180 / Math.pow(2, 7+zoom);

    deltaLatPerDeltaY: function(deltaY, zoom, startLat) {
        // more complex because of the curvature, we calculte it by difference
        var startY = this.latToY(startLat),
            endY = startY + deltaY * Math.pow(2, 28-7-zoom),
            endLat = this.YtoLat(endY);

        return ( endLat - startLat ); // = deltaLat

What are FTL files

An ftl file could just have a series of html tags just as a JSP page or it can have freemarker template coding for representing the objects passed on from a controller java file.
But, its actual ability is to combine the contents of a java class and view/client side stuff(html/ JQuery/ javascript etc). It is quite similar to velocity. You could map a method or object of a class to a freemarker (.ftl) page and use it as if it is a variable or a functionality created in the very page.

Is CSS Turing complete?

This answer is not accurate because it mix description of UTM and UTM itself (Universal Turing Machine).

We have good answer but from different perspective and it do not show directly flaws in current top answer.

First of all we can agree that human can work as UTM. This mean if we do

CSS + Human == UTM

Then CSS part is useless because all work can be done by Human who will do UTM part. Act of clicking can be UTM, because you do not click at random but only in specific places.

Instead of CSS I could use this text (Rule 110):

000 -> 0
001 -> 1
010 -> 1
011 -> 1
100 -> 0
101 -> 1
110 -> 1
111 -> 0

To guide my actions and result will be same. This mean this text UTM? No this is only input (description) that other UTM (human or computer) can read and run. Clicking is enough to run any UTM.

Critical part that CSS lack is ability to change of it own state in arbitrary way, if CSS could generate clicks then it would be UTM. Argument that your clicks are "crank" for CSS is not accurate because real "crank" for CSS is Layout Engine that run it and it should be enough to prove that CSS is UTM.

Export table data from one SQL Server to another

Yet another option if you have it available: c# .net. In particular, the Microsoft.SqlServer.Management.Smo namespace.

I use code similar to the following in a Script Component of one of my SSIS packages.

var tableToTransfer = "someTable";
var transferringTableSchema = "dbo";

var srvSource = new Server("sourceServer");
var dbSource = srvSource.Databases["sourceDB"];

var srvDestination = new Server("destinationServer"); 
var dbDestination = srvDestination.Databases["destinationDB"];

var xfr = 
    new Transfer(dbSource) {
        DestinationServer = srvDestination.Name,
        DestinationDatabase = dbDestination.Name,
        CopyAllObjects = false,
        DestinationLoginSecure = true,
        DropDestinationObjectsFirst = true,
        CopyData = true

xfr.Options.ContinueScriptingOnError = false; 
xfr.Options.WithDependencies = false; 


I think I had to explicitly search for and add the Microsoft.SqlServer.Smo library to the references. But outside of that, this has been working out for me.

Update: The namespace and libraries were more complicated than I remembered.

For libraries, add references to:

  • Microsoft.SqlServer.Smo.dll
  • Microsoft.SqlServer.SmoExtended.dll
  • Microsoft.SqlServer.ConnectionInfo.dll
  • Microsoft.SqlServer.Management.Sdk.Sfc.dll

For the Namespaces, add:

  • Microsoft.SqlServer.Management.Common
  • Microsoft.SqlServer.Management.Smo

How to set selectedIndex of select element using display text?

You can set the index by this code :

sel.selectedIndex = 0;

but remember a caution in this practice, You would not be able to call the server side onclick method if you select the previous value selected in the drop down..

Adding sheets to end of workbook in Excel (normal method not working?)

Try this

mainWB.Sheets.Add(After:=mainWB.Sheets(mainWB.Sheets.Count)).Name = new_sheet_name

ruby LoadError: cannot load such file

The problem shall have solved if you specify your path.


"require 'st.rb'" --> "require './st.rb'"

See if your problem get solved or not.

Can one class extend two classes?

No you cannot make a class extend to two classes.

A possible solution is to make it extend from another class, and make that class extend from another again.

How to check java bit version on Linux?

Works for every binary, not only java:

file - < $(which java) # heavyly bashic

cat `which java` | file - # universal

find_spec_for_exe': can't find gem bundler (>= 0.a) (Gem::GemNotFoundException)

I had to do rake clean --force. Then did gem install rake and so forth.

React - uncaught TypeError: Cannot read property 'setState' of undefined

  1. Check state check state whether you create particular property or not

this.state = {_x000D_
            name: "",_x000D_
            email: ""_x000D_
this.setState(() => ({ _x000D_
             comments: comments          //comments not available in state_x000D_

2.Check the (this) if you doing setState inside any function (i.e handleChange) check whether the function bind to this or the function should be arrow function .

## 3 ways for binding this to the below function##

//3 ways for binding this to the below function_x000D_
handleNameChange(e) {  _x000D_
     this.setState(() => ({ name }))_x000D_
// 1.Bind while callling function_x000D_
//2.make it as arrow function_x000D_
     handleNameChange((e)=> {  _x000D_
     this.setState(() => ({ name }))_x000D_
//3.Bind in constuctor _x000D_
constructor(props) {_x000D_
        this.state = {_x000D_
            name: "",_x000D_
            email: ""_x000D_
        this.handleNameChange = this.handleNameChange.bind(this)_x000D_

Select query with date condition

Be careful, you're unwittingly asking "where the date is greater than one divided by nine, divided by two thousand and eight".

Put # signs around the date, like this #1/09/2008#

How to initialize var?

Well, as others have stated, ambiguity in type is the issue. So the answer is no, C# doesn't let that happen because it's a strongly typed language, and it deals only with compile time known types. The compiler could have been designed to infer it as of type object, but the designers chose to avoid the extra complexity (in C# null has no type).

One alternative is

var foo = new { }; //anonymous type

Again note that you're initializing to a compile time known type, and at the end its not null, but anonymous object. It's only a few lines shorter than new object(). You can only reassign the anonymous type to foo in this one case, which may or may not be desirable.

Initializing to null with type not being known is out of question.

Unless you're using dynamic.

dynamic foo = null;
var foo = (dynamic)null; //overkill

Of course it is pretty useless, unless you want to reassign values to foo variable. You lose intellisense support as well in Visual Studio.

Lastly, as others have answered, you can have a specific type declared by casting;

var foo = (T)null;

So your options are:

//initializes to non-null; I like it; cant be reassigned a value of any type
var foo = new { }; 

//initializes to non-null; can be reassigned a value of any type
var foo = new object();

//initializes to null; dangerous and finds least use; can be reassigned a value of any type
dynamic foo = null;
var foo = (dynamic)null;

//initializes to null; more conventional; can be reassigned a value of any type
object foo = null;

//initializes to null; cannot be reassigned a value of any type
var foo = (T)null;

Rotating videos with FFmpeg

Have you tried transpose yet? Like (from the other answer)

 ffmpeg -i input -vf transpose=2 output

If you are using an old version, you have to update ffmpeg if you want to use the transpose feature, as it was added in October 2011.

The FFmpeg download page offers static builds that you can directly execute without having to compile them.

How to run sql script using SQL Server Management Studio?

Found this in another thread that helped me: Use xp_cmdshell and sqlcmd Is it possible to execute a text file from SQL query? - by Gulzar Nazim

EXEC xp_cmdshell  'sqlcmd -S ' + @DBServerName + ' -d  ' + @DBName + ' -i ' + @FilePathName

Failed to allocate memory: 8

In my case, changin screen resolution from WVGA720 to WSVGA works for me.

Pass entire form as data in jQuery Ajax function

In general use serialize() on the form element.

Please be mindful that multiple <select> options are serialized under the same key, e.g.

<select id="foo" name="foo" multiple="multiple">
    <option value="1">one</option>
    <option value="2">two</option>
    <option value="3">three</option>

will result in a query string that includes multiple occurences of the same query parameter:


which may not be what you want in the backend.

I use this JS code to reduce multiple parameters to a comma-separated single key (shamelessly copied from a commenter's response in a thread over at John Resig's place):

function compress(data) {
    data = data.replace(/([^&=]+=)([^&]*)(.*?)&\1([^&]*)/g, "$1$2,$4$3");
    return /([^&=]+=).*?&\1/.test(data) ? compress(data) : data;

which turns the above into:


In your JS code you'd call it like this:

var inputs = compress($("#your-form").serialize());

Hope that helps.

How to delete last item in list?

You need:

record = record[:-1]

before the for loop.

This will set record to the current record list but without the last item. You may, depending on your needs, want to ensure the list isn't empty before doing this.

How to pass IEnumerable list to controller in MVC including checkbox state?

Use a list instead and replace your foreach loop with a for loop:

@model IList<BlockedIPViewModel>

@using (Html.BeginForm()) 

    @for (var i = 0; i < Model.Count; i++) 
                @Html.HiddenFor(x => x[i].IP)           
                @Html.CheckBoxFor(x => x[i].Checked)
                @Html.DisplayFor(x => x[i].IP)
        <input type="submit" value="Unblock IPs" />

Alternatively you could use an editor template:

@model IEnumerable<BlockedIPViewModel>

@using (Html.BeginForm()) 
        <input type="submit" value="Unblock IPs" />

and then define the template ~/Views/Shared/EditorTemplates/BlockedIPViewModel.cshtml which will automatically be rendered for each element of the collection:

@model BlockedIPViewModel
        @Html.HiddenFor(x => x.IP)
        @Html.CheckBoxFor(x => x.Checked)
        @Html.DisplayFor(x => x.IP)

The reason you were getting null in your controller is because you didn't respect the naming convention for your input fields that the default model binder expects to successfully bind to a list. I invite you to read the following article.

Once you have read it, look at the generated HTML (and more specifically the names of the input fields) with my example and yours. Then compare and you will understand why yours doesn't work.

IIS7 folder permissions for web application

Running IIS 7.5, I had luck adding permissions for the local computer user IUSR. The app pool user didn't work.

Xcode variables

The best source is probably Apple's official documentation. The specific variable you are looking for is CONFIGURATION.

How to always show scrollbar

I had the same problem. The bar had the same background color. Try:


Is there a rule-of-thumb for how to divide a dataset into training and validation sets?

Perhaps a 63.2% / 36.8% is a reasonable choice. The reason would be that if you had a total sample size n and wanted to randomly sample with replacement (a.k.a. re-sample, as in the statistical bootstrap) n cases out of the initial n, the probability of an individual case being selected in the re-sample would be approximately 0.632, provided that n is not too small, as explained here:

For a sample of n=250, the probability of an individual case being selected for a re-sample to 4 digits is 0.6329. For a sample of n=20000, the probability is 0.6321.

How to set <iframe src="..."> without causing `unsafe value` exception?

This works me to Angular 5.2.0


import { Component, OnInit, Input } from '@angular/core';
import { DomSanitizer, SafeResourceUrl } from '@angular/platform-browser';

  selector: 'app-sarasa',
  templateUrl: './sarasa.component.html',
  styleUrls: ['./sarasa.component.scss']

export class Sarasa implements OnInit {
  url: string = "";
  urlSafe: SafeResourceUrl;

  constructor(public sanitizer: DomSanitizer) { }

  ngOnInit() {
    this.urlSafe= this.sanitizer.bypassSecurityTrustResourceUrl(this.url);



<iframe width="100%" height="100%" frameBorder="0" [src]="urlSafe"></iframe>

thats all folks!!!

How to set custom favicon in Express?

If you are using Express > 4.0, you could go for serve-favicon

cannot call member function without object

You are right - you declared a new use defined type (Name_pairs) and you need variable of that type to use it.

The code should go like this:

Name_pairs np;

Why is IoC / DI not common in Python?

I back "Jörg W Mittag" answer: "The Python implementation of DI/IoC is so lightweight that it completely vanishes".

To back up this statement, take a look at the famous Martin Fowler's example ported from Java to Python: Python:Design_Patterns:Inversion_of_Control

As you can see from the above link, a "Container" in Python can be written in 8 lines of code:

class Container:
    def __init__(self, system_data):
        for component_name, component_class, component_args in system_data:
            if type(component_class) == types.ClassType:
                args = [self.__dict__[arg] for arg in component_args]
                self.__dict__[component_name] = component_class(*args)
                self.__dict__[component_name] = component_class

How do I remove background-image in css?

div#a {
  background-image: url('../images/spacer.png');
  background-image: none !important;

I use a transparent spacer image in addition to the rule to remove the background image because IE6 seems to ignore the background-image: none even though it is marked !important.

Print to the same line and not a new line?

Based on Remi answer for Python 2.7+ use this:

from __future__ import print_function
import time

# status generator
def range_with_status(total):
    """ iterate from 0 to total and show progress in console """
    import sys
    n = 0
    while n < total:
        done = '#' * (n + 1)
        todo = '-' * (total - n - 1)
        s = '<{0}>'.format(done + todo)
        if not todo:
            s += '\n'
        if n > 0:
            s = '\r' + s
        print(s, end='\r')
        yield n
        n += 1

# example for use of status generator
for i in range_with_status(50):

PHP mail function doesn't complete sending of e-mail

You can see your errors by:


And my sample code is:

    use PHPMailer\PHPMailer\PHPMailer;
    require 'PHPMailer.php';
    require 'SMTP.php';
    require 'Exception.php';

    $name = $_POST['name'];
    $mailid = $_POST['mail'];
    $mail = new PHPMailer;
    $mail->SMTPDebug = 0;                   // Set mailer to use SMTP
    $mail->Host = '';         // Specify main and backup server
    $mail->Port = 587;                      // Set the SMTP port
    $mail->SMTPAuth = true;                 // Enable SMTP authentication
    $mail->Username = '[email protected]';  // SMTP username
    $mail->Password = 'password';           // SMTP password
    $mail->SMTPSecure = 'tls';              // Enable encryption, 'ssl' also accepted

    $mail->From = '[email protected]';
    $mail->FromName = 'name';
    $mail->AddAddress($mailid, $name);       // Name is optional
    $mail->IsHTML(true);                     // Set email format to HTML
    $mail->Subject = 'Here is the subject';
    $mail->Body    = 'Here is your message' ;
    $mail->AltBody = 'This is the body in plain text for non-HTML mail clients';
    if (!$mail->Send()) {
       echo 'Message could not be sent.';
       echo 'Mailer Error: ' . $mail->ErrorInfo;
    echo 'Message has been sent';

Converting HTML string into DOM elements?

Okay, I realized the answer myself, after I had to think about other people's answers. :P

var htmlContent = ... // a response via AJAX containing HTML
var e = document.createElement('div');
e.setAttribute('style', 'display: none;');
e.innerHTML = htmlContent;
var htmlConvertedIntoDom = e.lastChild.childNodes; // the HTML converted into a DOM element :), now let's remove the

font-family is inherit. How to find out the font-family in chrome developer pane?

Developer Tools > Elements > Computed > Rendered Fonts

The picture you attached to your question shows the Style tab. If you change to the next tab, Computed, you can check the Rendered Fonts, that shows the actual font-family rendered.

Developer Tools > Elements > Computed > Rendered Fonts

What's the difference between compiled and interpreted language?

It is a very murky distinction, and in fact generally not a property of a language itself, but rather of the program you are using to execute code in that language.

However, most languages are used primarily in one form or the other, and yes, Java is essentially always compiled, while javascript is essentially always interpreted.

To compile source code is to run a program on it that generates a binary, executable file that, when run, has the behavior defined by the source. For instance, javac compiles human-readbale .java files into machine-readable .class files.

To interpret source code is run a program on it that produces the defined behavior right away, without generating an intermediary file. For instance, when your web browser loads, it interprets a bunch of javascript (which you can look at by viewing the page source) and produces lots of the nice effects these pages have - for instance, upvoting, or the little notifier bars across the top.

Visual Studio 2015 installer hangs during install?

The old thread with many answers. but for me, these commands solved the problem.

regsvr32.exe /u "C:\Program Files (x86)\Common Files\microsoft shared\MSI Tools\mergemod.dll"

regsvr32.exe "C:\Program Files (x86)\Common Files\microsoft shared\MSI Tools\mergemod.dll"

sqldeveloper error message: Network adapter could not establish the connection error

Check the listener status to see if it is down:

ps -ef | grep tns

If you don't see output about the listener:

oracle 18244 /apps/oracle/product/11.2.0/db_1/bin/tnslsnr LISTENER -inherit

Then you will need to start it up. To do this, execute the lsnrctl command.

Type start in the LSNRCTL> prompt.

How to update a record using sequelize for node?

January 2020 Answer
The thing to understand is that there's an update method for the Model and a separate update method for an Instance (record). Model.update() updates ALL matching records and returns an array see Sequelize documentation. Instance.update() updates the record and returns an instance object.

So to update a single record per the question, the code would look something like this:

SequlizeModel.findOne({where: {id: 'some-id'}})
.then(record => {
  if (!record) {
    throw new Error('No record found')

  console.log(`retrieved record ${JSON.stringify(record,null,2)}`) 

  let values = {
    registered : true,
    email: '[email protected]',
    name: 'Joe Blogs'
  record.update(values).then( updatedRecord => {
    console.log(`updated record ${JSON.stringify(updatedRecord,null,2)}`)
    // login into your DB and confirm update

.catch((error) => {
  // do seomthing with the error
  throw new Error(error)

So, use Model.findOne() or Model.findByPkId() to get a handle a single Instance (record) and then use the Instance.update()

Convert Java String to sql.Timestamp

Have you tried using Timestamp.valueOf(String)? It looks like it should do almost exactly what you want - you just need to change the separator between your date and time to a space, and the ones between hours and minutes, and minutes and hours, to colons:

import java.sql.*;

public class Test {
    public static void main(String[] args) {
        String text = "2011-10-02 18:48:05.123456";
        Timestamp ts = Timestamp.valueOf(text);

Assuming you've already validated the string length, this will convert to the right format:

static String convertSeparators(String input) {
    char[] chars = input.toCharArray();
    chars[10] = ' ';
    chars[13] = ':';
    chars[16] = ':';
    return new String(chars);

Alternatively, parse down to milliseconds by taking a substring and using Joda Time or SimpleDateFormat (I vastly prefer Joda Time, but your mileage may vary). Then take the remainder of the string as another string and parse it with Integer.parseInt. You can then combine the values pretty easily:

Date date = parseDateFromFirstPart();
int micros = parseJustLastThreeDigits();

Timestamp ts = new Timestamp(date.getTime());
ts.setNanos(ts.getNanos() + micros * 1000);

How can I scroll up more (increase the scroll buffer) in iTerm2?

Solution: In order to increase your buffer history on iterm bash terminal you've got two options:

Go to iterm -> Preferences -> Profiles -> Terminal Tab -> Scrollback Buffer (section)

Option 1. select the checkbox Unlimited scrollback

Option 2. type the selected Scrollback lines numbers you'd like your terminal buffer to cache (See image below)

enter image description here

Oracle SQL query for Date format

if you are using same date format and have select query where date in oracle :

   select count(id) from Table_name where TO_DATE(Column_date)='07-OCT-2015';

To_DATE provided by oracle

Working with TIFFs (import, export) in Python using numpy

I recommend using the python bindings to OpenImageIO, it's the standard for dealing with various image formats in the vfx world. I've ovten found it more reliable in reading various compression types compared to PIL.

import OpenImageIO as oiio
input = ("/path/to/image.tif")

Prevent PDF file from downloading and printing

Why dont you show a generated Picture (screenshot) of the PDF?

Spring CORS No 'Access-Control-Allow-Origin' header is present

If you are using Spring Security ver >= 4.2 you can use Spring Security's native support instead of including Apache's:

public class WebConfig extends WebMvcConfigurerAdapter {

    public void addCorsMappings(CorsRegistry registry) {

The example above was copied from a Spring blog post in which you also can find information about how to configure CORS on a controller, specific controller methods, etc. Moreover, there is also XML configuration examples as well as Spring Boot integration.

How can I find all of the distinct file extensions in a folder hierarchy?

Recursive version:

find . -type f | sed -e 's/.*\.//' | sed -e 's/.*\///' | sort -u

If you want totals (how may times the extension was seen):

find . -type f | sed -e 's/.*\.//' | sed -e 's/.*\///' | sort | uniq -c | sort -rn

Non-recursive (single folder):

for f in *.*; do printf "%s\n" "${f##*.}"; done | sort -u

I've based this upon this forum post, credit should go there.

What's a good (free) visual merge tool for Git? (on windows)

What's wrong with using Git For Windows? From the repo view, there's an icon of the branch you're in (at the top), and if you click on manage you can drag&drop in a very visual and convenient way.

How to replace plain URLs with links?

Made some optimizations to Travis' Linkify() code above. I also fixed a bug where email addresses with subdomain type formats would not be matched (i.e. [email protected]).

In addition, I changed the implementation to prototype the String class so that items can be matched like so:

var text = '[email protected]';


Anyway, here's the script:

if(!String.linkify) {
    String.prototype.linkify = function() {

        // http://, https://, ftp://
        var urlPattern = /\b(?:https?|ftp):\/\/[a-z0-9-+&@#\/%?=~_|!:,.;]*[a-z0-9-+&@#\/%=~_|]/gim;

        // www. sans http:// or https://
        var pseudoUrlPattern = /(^|[^\/])(www\.[\S]+(\b|$))/gim;

        // Email addresses
        var emailAddressPattern = /[\w.]+@[a-zA-Z_-]+?(?:\.[a-zA-Z]{2,6})+/gim;

        return this
            .replace(urlPattern, '<a href="$&">$&</a>')
            .replace(pseudoUrlPattern, '$1<a href="http://$2">$2</a>')
            .replace(emailAddressPattern, '<a href="mailto:$&">$&</a>');

Should I size a textarea with CSS width / height or HTML cols / rows attributes?

I usually don't specify height, but do specify width: ... and rows and cols.

Usually, in my cases, only width and rows are needed, for the textarea to look nice in relation to other elems. (And cols is a fallback if someone doesn't use CSS, as explained in the other answers.)

((Specifying both rows and height feels a little bit like duplicating data I think?))

How do I find all files containing specific text on Linux?

If you strictly want to use find then use find + grep:

find /path/to/somewhere/ -type f -exec grep -nw 'textPattern' {} \;


  1. Use find to search files,
  2. Execute grep on all of them.

This gives you the power of find to find files.

  • Use -name Pattern if you want to grep only certain files:

find /path/to/somewhere/ -type f -name \*.cpp -exec grep -nw 'textPattern' {} \;

You can use different options of find to improve your file search.

Create PostgreSQL ROLE (user) if it doesn't exist

Simplify in a similar fashion to what you had in mind:

      SELECT FROM pg_catalog.pg_roles  -- SELECT list can be empty for this
      WHERE  rolname = 'my_user') THEN

      CREATE ROLE my_user LOGIN PASSWORD 'my_password';
   END IF;

(Building on @a_horse_with_no_name's answer and improved with @Gregory's comment.)

Unlike, for instance, with CREATE TABLE there is no IF NOT EXISTS clause for CREATE ROLE (up to at least pg 12). And you cannot execute dynamic DDL statements in plain SQL.

Your request to "avoid PL/pgSQL" is impossible except by using another PL. The DO statement uses plpgsql as default procedural language. The syntax allows to omit the explicit declaration:

DO [ LANGUAGE lang_name ] code
The name of the procedural language the code is written in. If omitted, the default is plpgsql.

Retrieving the text of the selected <option> in <select> element

Easy, simple way:

const select = document.getElementById('selectID');
const selectedOption = [].find(option => option.selected).text;

Best way to format if statement with multiple conditions

When condition is really complex I use the following style (PHP real life example):

if( $format_bool &&
        ( isset( $column_info['native_type'] )
            && stripos( $column_info['native_type'], 'bool' ) !== false
        || ( isset( $column_info['driver:decl_type'] )
            && stripos( $column_info['driver:decl_type'], 'bool' ) !== false
        || ( isset( $column_info['pdo_type'] )
            && $column_info['pdo_type'] == PDO::PARAM_BOOL

I believe it's more nice and readable than nesting multiple levels of if(). And in some cases like this you simply can't break complex condition into pieces because otherwise you would have to repeat the same statements in if() {...} block many times.

I also believe that adding some "air" into code is always a good idea. It improves readability greatly.

Disable single warning error

as @rampion mentioned, if you are in clang gcc, the warnings are by name, not number, and you'll need to do:

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wunused-variable"
// ..your code..
#pragma clang diagnostic pop

this info comes from here

Java Replace Character At Specific Position Of String?

Petar Ivanov's answer to replace a character at a specific index in a string question

String are immutable in Java. You can't change them.

You need to create a new string with the character replaced.

String myName = "domanokz";
String newName = myName.substring(0,4)+'x'+myName.substring(5);

Or you can use a StringBuilder:

StringBuilder myName = new StringBuilder("domanokz");
myName.setCharAt(4, 'x');


Xcode 10 Error: Multiple commands produce

Check your supported platforms!

We spent months looking into this issue with several our of child projects. We found that AVAILABLE_PLATFORMS was being set to "appletvos appletvsimulator iphoneos iphonesimulator macosx watchos watchsimulator" which was causing multiple platforms to be built, which would lead to the "Multiple commands produce error." For instance, "Foo" platform was building for both iOS and TVOS, and thus multiple build commands were creating a Foo.framework file.

As soon as we set

AVAILABLE_PLATFORMS = iphoneos iphonesimulator

in our root xcconfig file, this problem went away all child projects.

To check your config


xcodebuild -project FitbitMobile.xcodeproj -target "FitbitMobile" -showBuildSettings > BuildSettings.txt

See if the output is being set to what you'd expect. If you're an iOS app and you're building for tvOS, you'll want to update your config.

Run a JAR file from the command line and specify classpath

You can do a Runtime.getRuntime.exec(command) to relaunch the jar including classpath with args.

How can I solve equations in Python?

Use a different tool. Something like Wolfram Alpha, Maple, R, Octave, Matlab or any other algebra software package.

As a beginner you should probably not attempt to solve such a non-trivial problem.

Why is php not running?

Check out the apache config files. For Debian/Ubuntu theyre in /etc/apache2/sites-available/ for RedHat/CentOS/etc they're in /etc/httpd/conf.d/. If you've just installed it, the file in there is probably named default.

Make sure that the config file in there is pointing to the correct folder and then make sure your scripts are located there.

The line you're looking for in those files is DocumentRoot /path/to/directory.

For a blank install, your php files most likely needs to be in /var/www/.

What you'll also need to do is find your php.ini file, probably located at /etc/php5/apache2/php.ini or /etc/php.ini and find the entry for display_errors and switch it to On.

MD5 is 128 bits but why is it 32 characters?

A hex "character" (nibble) is different from a "character"

To be clear on the bits vs byte, vs characters.

  • 1 byte is 8 bits (for our purposes)
  • 8 bits provides 2**8 possible combinations: 256 combinations

When you look at a hex character,

  • 16 combinations of [0-9] + [a-f]: the full range of 0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f
  • 16 is less than 256, so one one hex character does not store a byte.
  • 16 is 2**4: that means one hex character can store 4 bits in a byte (half a byte).
  • Therefore, two hex characters, can store 8 bits, 2**8 combinations.
  • A byte represented as a hex character is [0-9a-f][0-9a-f] and that represents both halfs of a byte (we call a half-byte a nibble).

When you look at a regular single-byte character, (we're totally going to skip multi-byte and wide-characters here)

  • It can store far more than 16 combinations.
  • The capabilities of the character are determined by the encoding. For instance, the ISO 8859-1 that stores an entire byte, stores all this stuff
  • All that stuff takes the entire 2**8 range.
  • If a hex-character in an md5() could store all that, you'd see all the lowercase letters, all the uppercase letters, all the punctuation and things like ¡°ÀÐàð, whitespace like (newlines, and tabs), and control characters (which you can't even see and many of which aren't in use).

So they're clearly different and I hope that provides the best break down of the differences.

Using ChildActionOnly in MVC

FYI, [ChildActionOnly] is not available in ASP.NET MVC Core. see some info here

Excel CSV - Number cell format

You can simply format your range as Text.

Also here is a nice article on the number formats and how you can program them.

How to simulate key presses or a click with JavaScript?

Focus might be what your looking for. With tabbing or clicking I think u mean giving the element the focus. Same code as Russ (Sorry i stole it :P) but firing an other event.

// this must be done after input1 exists in the DOM
var element = document.getElementById("input1");

if (element) element.focus();

Windows batch script to unhide files hidden by virus

Try this one. Hope this is working fine.. :)

@ECHO off



set drvltr=

set /p drvltr=Enter Drive letter: 

attrib -s -h -a /s /d  %drvltr%:\*.*

ECHO Unhide Completed


How to filter an array/object by checking multiple values

You can use .filter() with boolean operators ie &&:

     var find = my_array.filter(function(result) {
       return result.param1 === "srting1" && result.param2 === 'string2';
     return find[0];

How do synchronized static methods work in Java and can I use it for loading Hibernate entities?

By using synchronized on a static method lock you will synchronize the class methods and attributes ( as opposed to instance methods and attributes )

So your assumption is correct.

I am wondering if making the method synchronized is the right approach to ensure thread-safety.

Not really. You should let your RDBMS do that work instead. They are good at this kind of stuff.

The only thing you will get by synchronizing the access to the database is to make your application terribly slow. Further more, in the code you posted you're building a Session Factory each time, that way, your application will spend more time accessing the DB than performing the actual job.

Imagine the following scenario:

Client A and B attempt to insert different information into record X of table T.

With your approach the only thing you're getting is to make sure one is called after the other, when this would happen anyway in the DB, because the RDBMS will prevent them from inserting half information from A and half from B at the same time. The result will be the same but only 5 times ( or more ) slower.

Probably it could be better to take a look at the "Transactions and Concurrency" chapter in the Hibernate documentation. Most of the times the problems you're trying to solve, have been solved already and a much better way.

How to declare a variable in SQL Server and use it in the same Stored Procedure

None of the above methods worked for me so i'm posting the way i did


DECLARE BrandName varchar(50);
DECLARE CategoryID,BrandID  int;
SELECT BrandID = BrandID FROM tblBrand 
WHERE BrandName = BrandName;

INSERT INTO tblBrandinCategory (CategoryID, BrandID) 
       VALUES (CategoryID, BrandID);

Regular expression to match non-ASCII characters?

Unicode Property Escapes are among the features of ES2018.

Basic Usage

With Unicode Property Escapes, you can match a letter from any language with the following simple regular expression:


Or with the shorthand, even terser:


Matching Words

Regarding the question's concrete use case (matching words), note that you can use Unicode Property Escapes in character classes, making it easy to match letters together with other word-characters like hyphens:


Stitching it all together, you could match words of all[1] languages with this beautifully short RegEx:


Example (shamelessly plugged from the answer above):

'Düsseldorf, Köln, ??????, ???, ??????? !@#$'.match(/[\p{L}-]+/ug)

// ["Düsseldorf", "Köln", "??????", "???", "???????"]

[1] Note that I'm not an expert on languages. You may still want to do your own research regarding other characters that might be parts of words besides letters and hyphens.

Browser Support

This feature is available in all major evergreen browsers.


If support for older browsers is needed, Unicode Property Escapes can be transpiled to ES5 with a tool called regexpu. There's an online demo available here. As you can see in the demo, you can in fact match non-latin letters today with the following (horribly long) ES5 regular expression:


If you're using Babel, there's also a regexpu-powered plugin for that (Babel v6 plugin, Babel v7 plugin).

How to Set OnClick attribute with value containing function in ie8?

You could also set onclick to call your function like this:

foo.onclick = function() { callYourJSFunction(arg1, arg2); };

This way, you can pass arguments too. .....

dbms_lob.getlength() vs. length() to find blob size in oracle

length and dbms_lob.getlength return the number of characters when applied to a CLOB (Character LOB). When applied to a BLOB (Binary LOB), dbms_lob.getlength will return the number of bytes, which may differ from the number of characters in a multi-byte character set.

As the documentation doesn't specify what happens when you apply length on a BLOB, I would advise against using it in that case. If you want the number of bytes in a BLOB, use dbms_lob.getlength.

Pointer to a string in C?

The very same. A C string is nothing but an array of characters, so a pointer to a string is a pointer to an array of characters. And a pointer to an array is the very same as a pointer to its first element.

What is the difference between `new Object()` and object literal notation?

Also, according to some of the O'Really javascript books....(quoted)

Another reason for using literals as opposed to the Object constructor is that there is no scope resolution. Because it’s possible that you have created a local constructor with the same name, the interpreter needs to look up the scope chain from the place you are calling Object() all the way up until it finds the global Object constructor.

Cannot resolve symbol 'AppCompatActivity'

I'll tell you how did i solved this problem in eclipse. Download zip file from this link. then extract this file,open project, in lib folder you will see one jar file named "android-support-v7-appcompat" , add this jar file into your project. Thats it. enter image description here

How can I use console logging in Internet Explorer?

You can access IE8 script console by launching the "Developer Tools" (F12). Click the "Script" tab, then click "Console" on the right.

From within your JavaScript code, you can do any of the following:

<script type="text/javascript">
    console.log('some msg');'information');
    console.warn('some warning');
    console.error('some error');
    console.assert(false, 'YOU FAIL');

Also, you can clear the Console by calling console.clear().

NOTE: It appears you must launch the Developer Tools first then refresh your page for this to work.

How to change a Git remote on Heroku

If you're working on the heroku remote (default):

heroku git:remote -a [app name]

If you want to specify a different remote, use the -r argument:

heroku git:remote -a [app name] -r [remote] 

EDIT: thanks to ??????? ???????? For pointing it out that there's no need to delete the old remote.

Convert DateTime in C# to yyyy-MM-dd format and Store it to MySql DateTime Field

Have you tried?

var isoDateTimeFormat = CultureInfo.InvariantCulture.DateTimeFormat;

// "2013-10-10T22:10:00"

// "2013-10-10 22:10:00Z"    

Also try using parameters when you store the c# datetime value in the mySql database, this might help.

How can I put a database under git (version control)?

I'd like to put the entire database under version control, what database engine can I use so that I can put the actual database under version control instead of its dump?

This is not database engine dependent. By Microsoft SQL Server there are lots of version controlling programs. I don't think that problem can be solved with git, you have to use a pgsql specific schema version control system. I don't know whether such a thing exists or not...

Convert Float to Int in Swift

Suppose you store float value in "X" and you are storing integer value in "Y".

Var Y = Int(x);


var myIntValue = Int(myFloatValue)

access denied for user @ 'localhost' to database ''

Try this: Adding users to MySQL

You need grant privileges to the user if you want external acess to database(ie. web pages).

warning: incompatible implicit declaration of built-in function ‘xyz’

I met these warnings on mempcpy function. Man page says this function is a GNU extension and synopsis shows:

#define _GNU_SOURCE
#include <string.h>

When #define is added to my source before the #include, declarations for the GNU extensions are made visible and warnings disappear.

Bootstrap 3 2-column form layout

As mentioned earlier, you can use the grid system to layout your inputs and labels anyway that you want. The trick is to remember that you can use rows within your columns to break them into twelfths as well.

The example below is one possible way to accomplish your goal and will put the two text boxes near Label3 on the same line when the screen is small or larger.

<!DOCTYPE html>_x000D_
<html lang="en">_x000D_
    <meta charset="utf-8">_x000D_
    <meta http-equiv="X-UA-Compatible" content="IE=edge">_x000D_
    <meta name="viewport" content="width=device-width, initial-scale=1">_x000D_
<link href="" rel="stylesheet"/>_x000D_
    <!-- HTML5 shim and Respond.js for IE8 support of HTML5 elements and media queries -->_x000D_
    <!-- WARNING: Respond.js doesn't work if you view the page via file:// -->_x000D_
    <!--[if lt IE 9]>_x000D_
      <script src=""></script>_x000D_
      <script src=""></script>_x000D_
    <div class="row">_x000D_
        <div class="col-xs-6 form-group">_x000D_
            <input class="form-control" type="text"/>_x000D_
        <div class="col-xs-6 form-group">_x000D_
            <input class="form-control" type="text"/>_x000D_
        <div class="col-xs-6">_x000D_
            <div class="row">_x000D_
                <label class="col-xs-12">Label3</label>_x000D_
            <div class="row">_x000D_
                <div class="col-xs-12 col-sm-6">_x000D_
                    <input class="form-control" type="text"/>_x000D_
                <div class="col-xs-12 col-sm-6">_x000D_
                    <input class="form-control" type="text"/>_x000D_
        <div class="col-xs-6 form-group">_x000D_
            <input class="form-control" type="text"/>_x000D_
<script src=""></script>_x000D_
<script src=""></script>_x000D_

SQL Server : export query as a .txt file

This is quite simple to do and the answer is available in other queries. For those of you who are viewing this:

select entries from my_entries where id='42' INTO OUTFILE 'bishwas.txt';

Switching the order of block elements with CSS

This method worked for me without flexbox:

#blockC {_x000D_
    border: 1px solid black;_x000D_
    padding: 20px;_x000D_
#blockC {_x000D_
    -webkit-transform: rotate(180deg);_x000D_
       -moz-transform: rotate(180deg);_x000D_
        -ms-transform: rotate(180deg);_x000D_
         -o-transform: rotate(180deg);_x000D_
            transform: rotate(180deg);_x000D_
<div class="reverseOrder">_x000D_
    <div id="blockA">Block A</div>_x000D_
    <div id="blockB">Block B</div>_x000D_
    <div id="blockC">Block C</div>_x000D_