Programs & Examples On #Ownership semantics

string.Replace in AngularJs

var oldString = "stackoverflow";
var str=oldString.replace(/stackover/g,"NO");
$scope.newString= str;

It works for me. Use an intermediate variable.

Send email with PHP from html form on submit with the same script

I think one error in the original code might have been that it had:

$message = echo getRequestURI();

instead of:

$message = getRequestURI();

(The code has since been edited though.)

The term 'ng' is not recognized as the name of a cmdlet

Installing angular cli globally solved my problem.

npm install -g @angular/cli

How can I change the Java Runtime Version on Windows (7)?

All you need to do is set the PATH environment variable in Windows to point to where your java6 bin directory is instead of the java7 directory.

Right click My Computer > Advanced System Settings > Advanced > Environmental Variables

If there is a JAVA_HOME environment variable set this to point to the correct directory as well.

How do you get assembler output from C/C++ source in gcc?

If what you want to see depends on the linking of the output, then objdump on the output object file/executable may also be useful in addition to the aforementioned gcc -S. Here's a very useful script by Loren Merritt that converts the default objdump syntax into the more readable nasm syntax:

#!/usr/bin/perl -w
$ptr='(BYTE|WORD|DWORD|QWORD|XMMWORD) PTR ';
$reg='(?:[er]?(?:[abcd]x|[sd]i|[sb]p)|[abcd][hl]|r1?[0-589][dwb]?|mm[0-7]|xmm1?[0-9])';
open FH, '-|', '/usr/bin/objdump', '-w', '-M', 'intel', @ARGV or die;
$prev = "";
while(<FH>){
    if(/$ptr/o) {
        s/$ptr(\[[^\[\]]+\],$reg)/$2/o or
        s/($reg,)$ptr(\[[^\[\]]+\])/$1$3/o or
        s/$ptr/lc $1/oe;
    }
    if($prev =~ /\t(repz )?ret / and
       $_ =~ /\tnop |\txchg *ax,ax$/) {
       # drop this line
    } else {
       print $prev;
       $prev = $_;
    }
}
print $prev;
close FH;

I suspect this can also be used on the output of gcc -S.

Extracting Path from OpenFileDialog path/filename

Here's the simple way to do It !

string fullPath =openFileDialog1.FileName;
string directory;
directory = fullPath.Substring(0, fullPath.LastIndexOf('\\'));

How to add a vertical Separator?

<Style x:Key="MySeparatorStyle" TargetType="{x:Type Separator}">
                <Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}"/>
                <Setter Property="Margin" Value="10,0,10,0"/>
                <Setter Property="Focusable" Value="false"/>
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="{x:Type Separator}">
                            <Border 
                                  BorderBrush="{TemplateBinding BorderBrush}" 
                                  BorderThickness="{TemplateBinding BorderThickness}" 
                                  Background="{TemplateBinding Background}" 
                                  Height="20" 
                                  Width="3" 
                                  SnapsToDevicePixels="true"/>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>

use

<StackPanel  Orientation="Horizontal"  >
       <TextBlock>name</TextBlock>
           <Separator Style="{StaticResource MySeparatorStyle}" ></Separator>
       <Button>preview</Button>
 </StackPanel>

How to write a UTF-8 file with Java?

Below sample code can read file line by line and write new file in UTF-8 format. Also, i am explicitly specifying Cp1252 encoding.

    public static void main(String args[]) throws IOException {

    BufferedReader br = new BufferedReader(new InputStreamReader(
            new FileInputStream("c:\\filenonUTF.txt"),
            "Cp1252"));
    String line;

    Writer out = new BufferedWriter(
            new OutputStreamWriter(new FileOutputStream(
                    "c:\\fileUTF.txt"), "UTF-8"));

    try {

        while ((line = br.readLine()) != null) {

            out.write(line);
            out.write("\n");

        }

    } finally {

        br.close();
        out.close();

    }
}

How to count items in JSON data

You're close. A really simple solution is just to get the length from the 'run' objects returned. No need to bother with 'load' or 'loads':

len(data['result'][0]['run'])

How to disable RecyclerView scrolling?

Create class which extend RecyclerView class

public class NonScrollRecyclerView extends RecyclerView {

    public NonScrollRecyclerView(Context context) {
        super(context);
    }

    public NonScrollRecyclerView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public NonScrollRecyclerView(Context context, @Nullable AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int heightMeasureSpec_custom = MeasureSpec.makeMeasureSpec(
                Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);
        super.onMeasure(widthMeasureSpec, heightMeasureSpec_custom);
        ViewGroup.LayoutParams params = getLayoutParams();
        params.height = getMeasuredHeight();
    }
}

This will disable the scroll event, but not the click events

Use this in your XML do the following:

  <com.yourpackage.xyx.NonScrollRecyclerView 
     ...
     ... 
  />

Headers and client library minor version mismatch

I got same php warring in my wordpress site...

Err: Warning: mysql_connect(): Headers and client library minor version mismatch. Headers:50547 Library:50628 in /home/lhu/public_html/innovacarrentalschennai.com/wp-includes/wp-db.php on line 1515

Cause: I updated wp 4.2 to 4.5 version (PHP and MySql mismatch )

I changed wp-db.php on line 1515

$this->dbh = mysql_connect( $this->dbhost, $this->dbuser, $this->dbpassword, $new_link, $client_flags );

to

if ( WP_DEBUG ) {
    $this->dbh = mysql_connect( $this->dbhost, $this->dbuser, $this->dbpassword, $new_link, $client_flags );
} else {
    $this->dbh = @mysql_connect( $this->dbhost, $this->dbuser, $this->dbpassword, $new_link, $client_flags );
}

Its got without warring err on my wordpress site

Button Width Match Parent

The most basic approach is using Container by define its width to infinite. See below example of code

Container(
    width: double.infinity,
    child:FlatButton(
        onPressed: () {
            //your action here
        },
        child: Text("Button"),

    )
)

How can I Insert data into SQL Server using VBNet

Function ExtSql(ByVal sql As String) As Boolean
    Dim cnn As SqlConnection
    Dim cmd As SqlCommand
    cnn = New SqlConnection(My.Settings.mySqlConnectionString)
    Try
        cnn.Open()
        cmd = New SqlCommand
        cmd.Connection = cnn
        cmd.CommandType = CommandType.Text
        cmd.CommandText = sql
        cmd.ExecuteNonQuery()
        cnn.Close()
        cmd.Dispose()
    Catch ex As Exception
        cnn.Close()
        Return False
    End Try
    Return True
End Function

How do I copy a hash in Ruby?

Hash can create a new hash from an existing hash:

irb(main):009:0> h1 = {1 => 2}
=> {1=>2}
irb(main):010:0> h2 = Hash[h1]
=> {1=>2}
irb(main):011:0> h1.object_id
=> 2150233660
irb(main):012:0> h2.object_id
=> 2150205060

T-SQL CASE Clause: How to specify WHEN NULL

try:

SELECT first_name + ISNULL(' '+last_name, '') AS Name FROM dbo.person

This adds the space to the last name, if it is null, the entire space+last name goes to NULL and you only get a first name, otherwise you get a firts+space+last name.

this will work as long as the default setting for concatenation with null strings is set:

SET CONCAT_NULL_YIELDS_NULL ON 

this shouldn't be a concern since the OFF mode is going away in future versions of SQl Server

Actual meaning of 'shell=True' in subprocess

Executing programs through the shell means that all user input passed to the program is interpreted according to the syntax and semantic rules of the invoked shell. At best, this only causes inconvenience to the user, because the user has to obey these rules. For instance, paths containing special shell characters like quotation marks or blanks must be escaped. At worst, it causes security leaks, because the user can execute arbitrary programs.

shell=True is sometimes convenient to make use of specific shell features like word splitting or parameter expansion. However, if such a feature is required, make use of other modules are given to you (e.g. os.path.expandvars() for parameter expansion or shlex for word splitting). This means more work, but avoids other problems.

In short: Avoid shell=True by all means.

Preserve Line Breaks From TextArea When Writing To MySQL

This works:

function getBreakText($t) {
    return strtr($t, array('\\r\\n' => '<br>', '\\r' => '<br>', '\\n' => '<br>'));
}

How do you connect to a MySQL database using Oracle SQL Developer?

Under Tools > Preferences > Databases there is a third party JDBC driver path that must be setup. Once the driver path is setup a separate 'MySQL' tab should appear on the New Connections dialog.

Note: This is the same jdbc connector that is available as a JAR download from the MySQL website.

iterating over each character of a String in ruby 1.8.6 (each_char)

"ABCDEFG".chars.each do |char|
  puts char
end

also

"ABCDEFG".each_char {|char| p char}

Ruby version >2.5.1

Can I clear cell contents without changing styling?

You should use the ClearContents method if you want to clear the content but preserve the formatting.

Worksheets("Sheet1").Range("A1:G37").ClearContents

Async image loading from url inside a UITableView cell - image changes to wrong image while scrolling

Here is the swift version (by using @Nitesh Borad objective C code) :-

   if let img: UIImage = UIImage(data: previewImg[indexPath.row]) {
                cell.cardPreview.image = img
            } else {
                // The image isn't cached, download the img data
                // We should perform this in a background thread
                let imgURL = NSURL(string: "webLink URL")
                let request: NSURLRequest = NSURLRequest(URL: imgURL!)
                let session = NSURLSession.sharedSession()
                let task = session.dataTaskWithRequest(request, completionHandler: {data, response, error -> Void in
                    let error = error
                    let data = data
                    if error == nil {
                        // Convert the downloaded data in to a UIImage object
                        let image = UIImage(data: data!)
                        // Store the image in to our cache
                        self.previewImg[indexPath.row] = data!
                        // Update the cell
                        dispatch_async(dispatch_get_main_queue(), {
                            if let cell: YourTableViewCell = tableView.cellForRowAtIndexPath(indexPath) as? YourTableViewCell {
                                cell.cardPreview.image = image
                            }
                        })
                    } else {
                        cell.cardPreview.image = UIImage(named: "defaultImage")
                    }
                })
                task.resume()
            }

Set formula to a range of cells

Use FormulaR1C1:

Cells((1,3),(10,3)).FormulaR1C1 = "=RC[-2]+RC[-1]"

Unlike Formula, FormulaR1C1 has relative referencing.

How to append data to div using JavaScript?

java script

document.getElementById("divID").html("this text will be added to div");

jquery

$("#divID").html("this text will be added to div");

Use .html() without any arguments to see that you have entered. You can use the browser console to quickly test these functions before using them in your code.

How do you extract a JAR in a UNIX filesystem with a single command and specify its target directory using the JAR command?

If your jar file already has an absolute pathname as shown, it is particularly easy:

cd /where/you/want/it; jar xf /path/to/jarfile.jar

That is, you have the shell executed by Python change directory for you and then run the extraction.

If your jar file does not already have an absolute pathname, then you have to convert the relative name to absolute (by prefixing it with the path of the current directory) so that jar can find it after the change of directory.

The only issues left to worry about are things like blanks in the path names.

How do you declare an object array in Java?

It's the other way round:

Vehicle[] car = new Vehicle[N];

This makes more sense, as the number of elements in the array isn't part of the type of car, but it is part of the initialization of the array whose reference you're initially assigning to car. You can then reassign it in another statement:

car = new Vehicle[10]; // Creates a new array

(Note that I've changed the type name to match Java naming conventions.)

For further information about arrays, see section 10 of the Java Language Specification.

Traversing text in Insert mode

While in insert mode, use CtrlO to go to normal mode for just one command:

CTRL-O h  move cursor left 
CTRL-O l  move cursor right
CTRL-O j  move cursor down
CTRL-O k  move cursor up

which is probably the simplest way to do what you want and is easy to remember.

Other very useful control keys in insert mode:

CTRL-W    delete word to the left of cursor
CTRL-O D  delete everything to the right of cursor
CTRL-U    delete everything to the left of cursor
CTRL-H    backspace/delete
CTRL-J    insert newline (easier than reaching for the return key)
CTRL-T    indent current line
CTRL-D    un-indent current line

these will eliminate many wasteful switches back to normal mode.

how to add the missing RANDR extension

I had the same problem with Firefox 30 + Selenium 2.49 + Ubuntu 15.04.

It worked fine with Ubuntu 14 but after upgrade to 15.04 I got same RANDR warning and problem at starting Firefox using Xfvb.

After adding +extension RANDR it worked again.

$ vim /etc/init/xvfb.conf

#!upstart
description "Xvfb Server as a daemon"

start on filesystem and started networking
stop on shutdown

respawn

env XVFB=/usr/bin/Xvfb
env XVFBARGS=":10 -screen 1 1024x768x24 -ac +extension GLX +extension RANDR +render -noreset"
env PIDFILE=/var/run/xvfb.pid

exec start-stop-daemon --start --quiet --make-pidfile --pidfile $PIDFILE --exec $XVFB -- $XVFBARGS >> /var/log/xvfb.log 2>&1

How can I zoom an HTML element in Firefox and Opera?

try this code to zoom the whole page in fireFox

-moz-transform: scale(2);

if I am using this code, the whole page scaled with y and x scroll not properly zoom

so Sorry to say fireFox not working well using "-moz-transform: scale(2);"

**

Simply you can't zoom your page using css in fireFox

**

How can we draw a vertical line in the webpage?

There are no vertical lines in html that you can use but you can fake one by absolutely positioning a div outside of your container with a top:0; and bottom:0; style.

Try this:

CSS

.vr {
    width:10px;
    background-color:#000;
    position:absolute;
    top:0;
    bottom:0;
    left:150px;
}

HTML

<div class="vr">&nbsp;</div>

Demo

Can constructors throw exceptions in Java?

Yes, it can throw an exception and you can declare that in the signature of the constructor too as shown in the example below:

public class ConstructorTest
{
    public ConstructorTest() throws InterruptedException
    {
        System.out.println("Preparing object....");
        Thread.sleep(1000);
        System.out.println("Object ready");
    }

    public static void main(String ... args)
    {
        try
        {
            ConstructorTest test = new ConstructorTest();
        }
        catch (InterruptedException e)
        {
            System.out.println("Got interrupted...");
        }
    }
}

Excel select a value from a cell having row number calculated

You could use the INDIRECT function. This takes a string and converts it into a range

More info here

=INDIRECT("K"&A2)

But it's preferable to use INDEX as it is less volatile.

=INDEX(K:K,A2)

This returns a value or the reference to a value from within a table or range

More info here

Put either function into cell B2 and fill down.

Oracle SQL Developer: Failure - Test failed: The Network Adapter could not establish the connection?

I am answering this for the benefit of future community users. There were multiple issues. If you encounter this problem, I suggest you look for the following:

  • Make sure your tnsnames.ora is complete and has the databases you wish to connect to
  • Make sure you can tnsping the server you wish to connect to
  • On the server, make sure it will be open on the port you desire with the specific application you are using.

Once I did these three things, I solved my problem.

What's the difference between Sender, From and Return-Path?

So, over SMTP when a message is submitted, the SMTP envelope (sender, recipients, etc.) is different from the actual data of the message.

The Sender header is used to identify in the message who submitted it. This is usually the same as the From header, which is who the message is from. However, it can differ in some cases where a mail agent is sending messages on behalf of someone else.

The Return-Path header is used to indicate to the recipient (or receiving MTA) where non-delivery receipts are to be sent.

For example, take a server that allows users to send mail from a web page. So, [email protected] types in a message and submits it. The server then sends the message to its recipient with From set to [email protected]. The actual SMTP submission uses different credentials, something like [email protected]. So, the sender header is set to [email protected], to indicate the From header doesn't indicate who actually submitted the message.

In this case, if the message cannot be sent, it's probably better for the agent to receive the non-delivery report, and so Return-Path would also be set to [email protected] so that any delivery reports go to it instead of the sender.

If you are doing just that, a form submission to send e-mail, then this is probably a direct parallel with how you'd set the headers.

Difference between two DateTimes C#?

The time difference b/w to time will be shown use this method.

 private void HoursCalculator()
    {
        var t1 = txtfromtime.Text.Trim();
        var t2 = txttotime.Text.Trim();
        var Fromtime = t1.Substring(6);
        var Totime = t2.Substring(6);
        if (Fromtime == "M")
        {
             Fromtime = t1.Substring(5);
        }
        if (Totime == "M")
        {
            Totime = t2.Substring(5);
        }

        if (Fromtime=="PM" && Totime=="AM" )
        {
            var dt1 = DateTime.Parse("1900-01-01 " + txtfromtime.Text.Trim());
            var dt2 = DateTime.Parse("1900-01-02 " + txttotime.Text.Trim());
            var t = dt1.Subtract(dt2);
            //int temp = Convert.ToInt32(t.Hours);
            //temp = temp / 2;
            lblHours.Text =t.Hours.ToString() + ":" + t.Minutes.ToString();

        }
        else if (Fromtime == "AM" && Totime == "PM")
        {
            var dt1 = DateTime.Parse("1900-01-01 " + txtfromtime.Text.Trim());
            var dt2 = DateTime.Parse("1900-01-01 " + txttotime.Text.Trim());
            TimeSpan t = (dt2.Subtract(dt1));
            lblHours.Text = t.Hours.ToString() + ":" + t.Minutes.ToString();
        }
        else
        {
            var dt1 = DateTime.Parse("1900-01-01 " + txtfromtime.Text.Trim());
            var dt2 = DateTime.Parse("1900-01-01 " + txttotime.Text.Trim());
            TimeSpan t = (dt2.Subtract(dt1));
            lblHours.Text = t.Hours.ToString() + ":" + t.Minutes.ToString();
        }
    }

use your field id's

var t1 captures a value of 4:00AM

check this code may be helpful to someone.

Where can I find the TypeScript version installed in Visual Studio?

You can do npm list | grep typescript if it's installed through npm.

How to replace multiple strings in a file using PowerShell

One option is to chain the -replace operations together. The ` at the end of each line escapes the newline, causing PowerShell to continue parsing the expression on the next line:

$original_file = 'path\filename.abc'
$destination_file =  'path\filename.abc.new'
(Get-Content $original_file) | Foreach-Object {
    $_ -replace 'something1', 'something1aa' `
       -replace 'something2', 'something2bb' `
       -replace 'something3', 'something3cc' `
       -replace 'something4', 'something4dd' `
       -replace 'something5', 'something5dsf' `
       -replace 'something6', 'something6dfsfds'
    } | Set-Content $destination_file

Another option would be to assign an intermediate variable:

$x = $_ -replace 'something1', 'something1aa'
$x = $x -replace 'something2', 'something2bb'
...
$x

Timer function to provide time in nano seconds using C++

With that level of accuracy, it would be better to reason in CPU tick rather than in system call like clock(). And do not forget that if it takes more than one nanosecond to execute an instruction... having a nanosecond accuracy is pretty much impossible.

Still, something like that is a start:

Here's the actual code to retrieve number of 80x86 CPU clock ticks passed since the CPU was last started. It will work on Pentium and above (386/486 not supported). This code is actually MS Visual C++ specific, but can be probably very easy ported to whatever else, as long as it supports inline assembly.

inline __int64 GetCpuClocks()
{

    // Counter
    struct { int32 low, high; } counter;

    // Use RDTSC instruction to get clocks count
    __asm push EAX
    __asm push EDX
    __asm __emit 0fh __asm __emit 031h // RDTSC
    __asm mov counter.low, EAX
    __asm mov counter.high, EDX
    __asm pop EDX
    __asm pop EAX

    // Return result
    return *(__int64 *)(&counter);

}

This function has also the advantage of being extremely fast - it usually takes no more than 50 cpu cycles to execute.

Using the Timing Figures:
If you need to translate the clock counts into true elapsed time, divide the results by your chip's clock speed. Remember that the "rated" GHz is likely to be slightly different from the actual speed of your chip. To check your chip's true speed, you can use several very good utilities or the Win32 call, QueryPerformanceFrequency().

Subset dataframe by multiple logical conditions of rows to remove

This answer is more meant to explain why, not how. The '==' operator in R is vectorized in a same way as the '+' operator. It matches the elements of whatever is on the left side to the elements of whatever is on the right side, per element. For example:

> 1:3 == 1:3
[1] TRUE TRUE TRUE

Here the first test is 1==1 which is TRUE, the second 2==2 and the third 3==3. Notice that this returns a FALSE in the first and second element because the order is wrong:

> 3:1 == 1:3
[1] FALSE  TRUE FALSE

Now if one object is smaller then the other object then the smaller object is repeated as much as it takes to match the larger object. If the size of the larger object is not a multiplication of the size of the smaller object you get a warning that not all elements are repeated. For example:

>  1:2 == 1:3
[1]  TRUE  TRUE FALSE
Warning message:
In 1:2 == 1:3 :
  longer object length is not a multiple of shorter object length

Here the first match is 1==1, then 2==2, and finally 1==3 (FALSE) because the left side is smaller. If one of the sides is only one element then that is repeated:

> 1:3 == 1
[1]  TRUE FALSE FALSE

The correct operator to test if an element is in a vector is indeed '%in%' which is vectorized only to the left element (for each element in the left vector it is tested if it is part of any object in the right element).

Alternatively, you can use '&' to combine two logical statements. '&' takes two elements and checks elementwise if both are TRUE:

> 1:3 == 1 & 1:3 != 2
[1]  TRUE FALSE FALSE

How to create a notification with NotificationCompat.Builder?

You can try this code this works fine for me:

    NotificationCompat.Builder mBuilder= new NotificationCompat.Builder(this);

    Intent i = new Intent(noti.this, Xyz_activtiy.class);
    PendingIntent pendingIntent= PendingIntent.getActivity(this,0,i,0);

    mBuilder.setAutoCancel(true);
    mBuilder.setDefaults(NotificationCompat.DEFAULT_ALL);
    mBuilder.setWhen(20000);
    mBuilder.setTicker("Ticker");
    mBuilder.setContentInfo("Info");
    mBuilder.setContentIntent(pendingIntent);
    mBuilder.setSmallIcon(R.drawable.home);
    mBuilder.setContentTitle("New notification title");
    mBuilder.setContentText("Notification text");
    mBuilder.setSound(RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION));

    NotificationManager notificationManager= (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
    notificationManager.notify(2,mBuilder.build());

How to log PostgreSQL queries?

In your data/postgresql.conf file, change the log_statement setting to 'all'.


Edit

Looking at your new information, I'd say there may be a few other settings to verify:

  • make sure you have turned on the log_destination variable
  • make sure you turn on the logging_collector
  • also make sure that the log_directory directory already exists inside of the data directory, and that the postgres user can write to it.

How to get the index of an element in an IEnumerable?

An alternative to finding the index after the fact is to wrap the Enumerable, somewhat similar to using the Linq GroupBy() method.

public static class IndexedEnumerable
{
    public static IndexedEnumerable<T> ToIndexed<T>(this IEnumerable<T> items)
    {
        return IndexedEnumerable<T>.Create(items);
    }
}

public class IndexedEnumerable<T> : IEnumerable<IndexedEnumerable<T>.IndexedItem>
{
    private readonly IEnumerable<IndexedItem> _items;

    public IndexedEnumerable(IEnumerable<IndexedItem> items)
    {
        _items = items;
    }

    public class IndexedItem
    {
        public IndexedItem(int index, T value)
        {
            Index = index;
            Value = value;
        }

        public T Value { get; private set; }
        public int Index { get; private set; }
    }

    public static IndexedEnumerable<T> Create(IEnumerable<T> items)
    {
        return new IndexedEnumerable<T>(items.Select((item, index) => new IndexedItem(index, item)));
    }

    public IEnumerator<IndexedItem> GetEnumerator()
    {
        return _items.GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }
}

Which gives a use case of:

var items = new[] {1, 2, 3};
var indexedItems = items.ToIndexed();
foreach (var item in indexedItems)
{
    Console.WriteLine("items[{0}] = {1}", item.Index, item.Value);
}

How do I run pip on python for windows?

First go to the pip documentation if not install before: http://pip.readthedocs.org/en/stable/installing/

and follow the install pip which is first download get-pip.py from https://bootstrap.pypa.io/get-pip.py

Then run the following (which may require administrator access): python get-pip.py

TypeError: no implicit conversion of Symbol into Integer

This error shows up when you are treating an array or string as a Hash. In this line myHash.each do |item| you are assigning item to a two-element array [key, value], so item[:symbol] throws an error.

Sending HTML mail using a shell script

cat > mail.txt <<EOL
To: <email>
Subject: <subject>
Content-Type: text/html

<html>
$(cat <report-table-*.html>)
This report in <a href="<url>">SVN</a>
</html>

EOL

And then:

sendmail -t < mail.txt

Apply multiple functions to multiple groupby columns

For the first part you can pass a dict of column names for keys and a list of functions for the values:

In [28]: df
Out[28]:
          A         B         C         D         E  GRP
0  0.395670  0.219560  0.600644  0.613445  0.242893    0
1  0.323911  0.464584  0.107215  0.204072  0.927325    0
2  0.321358  0.076037  0.166946  0.439661  0.914612    1
3  0.133466  0.447946  0.014815  0.130781  0.268290    1

In [26]: f = {'A':['sum','mean'], 'B':['prod']}

In [27]: df.groupby('GRP').agg(f)
Out[27]:
            A                   B
          sum      mean      prod
GRP
0    0.719580  0.359790  0.102004
1    0.454824  0.227412  0.034060

UPDATE 1:

Because the aggregate function works on Series, references to the other column names are lost. To get around this, you can reference the full dataframe and index it using the group indices within the lambda function.

Here's a hacky workaround:

In [67]: f = {'A':['sum','mean'], 'B':['prod'], 'D': lambda g: df.loc[g.index].E.sum()}

In [69]: df.groupby('GRP').agg(f)
Out[69]:
            A                   B         D
          sum      mean      prod  <lambda>
GRP
0    0.719580  0.359790  0.102004  1.170219
1    0.454824  0.227412  0.034060  1.182901

Here, the resultant 'D' column is made up of the summed 'E' values.

UPDATE 2:

Here's a method that I think will do everything you ask. First make a custom lambda function. Below, g references the group. When aggregating, g will be a Series. Passing g.index to df.ix[] selects the current group from df. I then test if column C is less than 0.5. The returned boolean series is passed to g[] which selects only those rows meeting the criteria.

In [95]: cust = lambda g: g[df.loc[g.index]['C'] < 0.5].sum()

In [96]: f = {'A':['sum','mean'], 'B':['prod'], 'D': {'my name': cust}}

In [97]: df.groupby('GRP').agg(f)
Out[97]:
            A                   B         D
          sum      mean      prod   my name
GRP
0    0.719580  0.359790  0.102004  0.204072
1    0.454824  0.227412  0.034060  0.570441

How to SELECT in Oracle using a DBLINK located in a different schema?

I don't think it is possible to share a database link between more than one user but not all. They are either private (for one user only) or public (for all users).

A good way around this is to create a view in SCHEMA_B that exposes the table you want to access through the database link. This will also give you good control over who is allowed to select from the database link, as you can control the access to the view.

Do like this:

create database link db_link... as before;
create view mytable_view as select * from mytable@db_link;
grant select on mytable_view to myuser;

How to prevent background scrolling when Bootstrap 3 modal open on mobile browsers?

$('.modal') 
.on('shown', function(){ 
  console.log('show'); 
  $('body').css({overflow: 'hidden'}); 
}) 
.on('hidden', function(){ 
  $('body').css({overflow: ''}); 
}); 

use this one

Using LINQ to group by multiple properties and sum

Linus is spot on in the approach, but a few properties are off. It looks like 'AgencyContractId' is your Primary Key, which is unrelated to the output you want to give the user. I think this is what you want (assuming you change your ViewModel to match the data you say you want in your view).

var agencyContracts = _agencyContractsRepository.AgencyContracts
    .GroupBy(ac => new
                   {
                       ac.AgencyID,
                       ac.VendorID,
                       ac.RegionID
                   })
    .Select(ac => new AgencyContractViewModel
                   {
                       AgencyId = ac.Key.AgencyID,
                       VendorId = ac.Key.VendorID,
                       RegionId = ac.Key.RegionID,
                       Total = ac.Sum(acs => acs.Amount) + ac.Sum(acs => acs.Fee)
                   });

How to HTML encode/escape a string? Is there a built-in?

ERB::Util.html_escape can be used anywhere. It is available without using require in Rails.

Parse date without timezone javascript

Since it is really a formatting issue when displaying the date (e.g. displays in local time), I like to use the new(ish) Intl.DateTimeFormat object to perform the formatting as it is more explicit and provides more output options:

const dateOptions = { timeZone: 'UTC', month: 'long', day: 'numeric', year: 'numeric' };

const dateFormatter = new Intl.DateTimeFormat('en-US', dateOptions);
const dateAsFormattedString = dateFormatter.format(new Date('2019-06-01T00:00:00.000+00:00'));

console.log(dateAsFormattedString) // "June 1, 2019"

As shown, by setting the timeZone to 'UTC' it will not perform local conversions. As a bonus, it also allows you to create more polished outputs. You can read more about the Intl.DateTimeFormat object from Mozilla - Intl.DateTimeFormat.

Edit:

The same functionality can be achieved without creating a new Intl.DateTimeFormat object. Simply pass the locale and date options directly into the toLocaleDateString() function.

const dateOptions = { timeZone: 'UTC', month: 'long', day: 'numeric', year: 'numeric' };
const myDate = new Date('2019-06-01T00:00:00.000+00:00');
today.toLocaleDateString('en-US', dateOptions); // "June 1, 2019"

Emulate/Simulate iOS in Linux

The only solution I can think of is to install VMWare or any other VT then install OSX on a VM.

It works pretty good for testing.

Looping through a Scripting.Dictionary using index/item number

Adding to assylias's answer - assylias shows us D.ITEMS is a method that returns an array. Knowing that, we don't need the variant array a(i) [See caveat below]. We just need to use the proper array syntax.

For i = 0 To d.Count - 1
    s = d.Items()(i)
    Debug.Print s
Next i()

KEYS works the same way

For i = 0 To d.Count - 1
    Debug.Print d.Keys()(i), d.Items()(i)
Next i

This syntax is also useful for the SPLIT function which may help make this clearer. SPLIT also returns an array with lower bounds at 0. Thus, the following prints "C".

Debug.Print Split("A,B,C,D", ",")(2)

SPLIT is a function. Its parameters are in the first set of parentheses. Methods and Functions always use the first set of parentheses for parameters, even if no parameters are needed. In the example SPLIT returns the array {"A","B","C","D"}. Since it returns an array we can use a second set of parentheses to identify an element within the returned array just as we would any array.

Caveat: This shorter syntax may not be as efficient as using the variant array a() when iterating through the entire dictionary since the shorter syntax invokes the dictionary's Items method with each iteration. The shorter syntax is best for plucking a single item by number from a dictionary.

How do I set up Android Studio to work completely offline?

File > Settings > Build, Execution, Deployment > Gradle > Offline work

SSIS package creating Hresult: 0x80004005 Description: "Login timeout expired" error

The answer here is not clear, so I wanted to add more detail.

Using the link provided above, I performed the following step.

In my XML config manager I changed the "Provider" to SQLOLEDB.1 rather than SQLNCLI.1. This got me past this error.

This information is available at the link the OP posted in the Answer.

The link the got me there: http://social.msdn.microsoft.com/Forums/en-US/sqlintegrationservices/thread/fab0e3bf-4adf-4f17-b9f6-7b7f9db6523c/

How to solve 'Redirect has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header'?

I had the same problem in my Vue.js and SpringBoot projects. If somebody work with spring you can add this code:

@Bean
public FilterRegistrationBean simpleCorsFilter() {  
    UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();  
    CorsConfiguration config = new CorsConfiguration();  
    config.setAllowCredentials(true); 
    // *** URL below needs to match the Vue client URL and port ***
    config.setAllowedOrigins(Collections.singletonList("http://localhost:8080")); 
    config.setAllowedMethods(Collections.singletonList("*"));  
    config.setAllowedHeaders(Collections.singletonList("*"));  
    source.registerCorsConfiguration("/**", config);  
    FilterRegistrationBean bean = new FilterRegistrationBean<>(new CorsFilter(source));
    bean.setOrder(Ordered.HIGHEST_PRECEDENCE);  
    return bean;  
}   

I found solution in this article Build a Simple CRUD App with Spring Boot and Vue.js

Automatic vertical scroll bar in WPF TextBlock?

Something better would be:

<Grid Width="Your-specified-value" >
    <ScrollViewer>
         <TextBlock Width="Auto" TextWrapping="Wrap" />
    </ScrollViewer>
</Grid>

This makes sure that the text in your textblock does not overflow and overlap the elements below the textblock as may be the case if you do not use the grid. That happened to me when I tried other solutions even though the textblock was already in a grid with other elements. Keep in mind that the width of the textblock should be Auto and you should specify the desired with in the Grid element. I did this in my code and it works beautifully. HTH.

In reactJS, how to copy text to clipboard?

 copyclip = (item) => {
    var textField = document.createElement('textarea')
    textField.innerText = item
    document.body.appendChild(textField)
    textField.select()
    document.execCommand('copy')
    this.setState({'copy':"Copied"});
    textField.remove()
    setTimeout(() => {
      this.setState({'copy':""});
    }, 1000);
 }

 <span   className="cursor-pointer ml-1" onClick={()=> this.copyclip(passTextFromHere)} >Copy</span> <small>{this.state.copy}</small>

Handling the TAB character in Java

You can also use the tab character '\t' to represent a tab, instead of "\t".

char c ='t';
char c =(char)9;

nginx upload client_max_body_size issue

From the documentation:

It is necessary to keep in mind that the browsers do not know how to correctly show this error.

I suspect this is what's happening, if you inspect the HTTP to-and-fro using tools such as Firebug or Live HTTP Headers (both Firefox extensions) you'll be able to see what's really going on.

Wrap text in <td> tag

I believe you've encountered the catch 22 of tables. Tables are great for wrapping up content in a tabular structure and they do a wonderful job of "stretching" to meet the needs of the content they contain.

By default the table cells will stretch to fit content... thus your text just makes it wider.

There's a few solutions.

1.) You can try setting a max-width on the TD.

<td style="max-width:150px;">

2.) You can try putting your text in a wrapping element (e.g. a span) and set constraints on it.

<td><span style="max-width:150px;">Hello World...</span></td>

Be aware though that older versions of IE don't support min/max-width.

Since IE doesn't support max-width natively you'll need to add a hack if you want to force it to. There's several ways to add a hack, this is just one.

On page load, for IE6 only, get the rendered width of the table (in pixels) then get 15% of that and apply that as the width to the first TD in that column (or TH if you have headers) again, in pixels.

What does elementFormDefault do in XSD?

New, detailed answer and explanation to an old, frequently asked question...

Short answer: If you don't add elementFormDefault="qualified" to xsd:schema, then the default unqualified value means that locally declared elements are in no namespace.

There's a lot of confusion regarding what elementFormDefault does, but this can be quickly clarified with a short example...

Streamlined version of your XSD:

<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema"
        xmlns:target="http://www.levijackson.net/web340/ns"
        targetNamespace="http://www.levijackson.net/web340/ns">
  <element name="assignments">
    <complexType>
      <sequence>
        <element name="assignment" type="target:assignmentInfo" 
                 minOccurs="1" maxOccurs="unbounded"/>
      </sequence>
    </complexType>
  </element>
  <complexType name="assignmentInfo">
    <sequence>
      <element name="name" type="string"/>
    </sequence>
    <attribute name="id" type="string" use="required"/>
  </complexType>
</schema>

Key points:

  • The assignment element is locally defined.
  • Elements locally defined in XSD are in no namespace by default.
    • This is because the default value for elementFormDefault is unqualified.
    • This arguably is a design mistake by the creators of XSD.
    • Standard practice is to always use elementFormDefault="qualified" so that assignment is in the target namespace as one would expect.
  • It is a rarely used form attribute on xs:element declarations for which elementFormDefault establishes default values.

Seemingly Valid XML

This XML looks like it should be valid according to the above XSD:

<assignments xmlns="http://www.levijackson.net/web340/ns"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://www.levijackson.net/web340/ns try.xsd">
  <assignment id="a1">
    <name>John</name>
  </assignment>
</assignments>

Notice:

  • The default namespace on assignments places assignments and all of its descendents in the default namespace (http://www.levijackson.net/web340/ns).

Perplexing Validation Error

Despite looking valid, the above XML yields the following confusing validation error:

[Error] try.xml:4:23: cvc-complex-type.2.4.a: Invalid content was found starting with element 'assignment'. One of '{assignment}' is expected.

Notes:

  • You would not be the first developer to curse this diagnostic that seems to say that the content is invalid because it expected to find an assignment element but it actually found an assignment element. (WTF)
  • What this really means: The { and } around assignment means that validation was expecting assignment in no namespace here. Unfortunately, when it says that it found an assignment element, it doesn't mention that it found it in a default namespace which differs from no namespace.

Solution

  • Vast majority of the time: Add elementFormDefault="qualified" to the xsd:schema element of the XSD. This means valid XML must place elements in the target namespace when locally declared in the XSD; otherwise, valid XML must place locally declared elements in no namespace.
  • Tiny minority of the time: Change the XML to comply with the XSD's requirement that assignment be in no namespace. This can be achieved, for example, by adding xmlns="" to the assignment element.

Credits: Thanks to Michael Kay for helpful feedback on this answer.

How to change the colors of a PNG image easily?

Use Photoshop, Paint.NET or similar software and adjust Hue.

Could not load type 'System.ServiceModel.Activation.HttpModule' from assembly 'System.ServiceModel

Try with

c:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.exe -iru

When multiple versions of the .NET Framework are executing side-by-side on a single computer, the ASP.NET ISAPI version mapped to an ASP.NET application determines which version of the common language runtime (CLR) is used for the application.

Above command will Installs the version of ASP.NET that is associated with Aspnet_regiis.exe and only registers ASP.NET in IIS.

https://support.microsoft.com/en-us/help/2015129/error-message-after-you-install-the--net-framework-4-0-could-not-load

Disable resizing of a Windows Forms form

There is far more efficient answer: just put the following instructions in the Form_Load:

Me.MinimumSize = New Size(Width, Height)
Me.MaximumSize = Me.MinimumSize

Basic http file downloading and saving to disk in python?

A clean way to download a file is:

import urllib

testfile = urllib.URLopener()
testfile.retrieve("http://randomsite.com/file.gz", "file.gz")

This downloads a file from a website and names it file.gz. This is one of my favorite solutions, from Downloading a picture via urllib and python.

This example uses the urllib library, and it will directly retrieve the file form a source.

PHP filesize MB/KB conversion

I think this is a better approach. Simple and straight forward.

public function sizeFilter( $bytes )
{
    $label = array( 'B', 'KB', 'MB', 'GB', 'TB', 'PB' );
    for( $i = 0; $bytes >= 1024 && $i < ( count( $label ) -1 ); $bytes /= 1024, $i++ );
    return( round( $bytes, 2 ) . " " . $label[$i] );
}

How to force a script reload and re-execute?

Here's a method which is similar to Kelly's but will remove any pre-existing script with the same source, and uses jQuery.

<script>
    function reload_js(src) {
        $('script[src="' + src + '"]').remove();
        $('<script>').attr('src', src).appendTo('head');
    }
    reload_js('source_file.js');
</script>

Note that the 'type' attribute is no longer needed for scripts as of HTML5. (http://www.w3.org/html/wg/drafts/html/master/scripting-1.html#the-script-element)

Angular2 - TypeScript : Increment a number after timeout in AppComponent

You should put your processing into the class constructor or an OnInit hook method.

Create line after text with css

I am not experienced at all so feel free to correct things. However, I tried all these answers, but always had a problem in some screen. So I tried the following that worked for me and looks as I want it in almost all screens with the exception of mobile.

<div class="wrapper">
   <div id="Section-Title">
     <div id="h2"> YOUR TITLE
        <div id="line"><hr></div>
     </div>
   </div>
</div>

CSS:

.wrapper{
background:#fff;
max-width:100%;
margin:20px auto;
padding:50px 5%;}

#Section-Title{
margin: 2% auto;
width:98%;
overflow: hidden;}

#h2{
float:left;
width:100%;
position:relative;
z-index:1;
font-family:Arial, Helvetica, sans-serif;
font-size:1.5vw;}

#h2 #line {
display:inline-block;
float:right;
margin:auto;
margin-left:10px;
width:90%;
position:absolute;
top:-5%;}

#Section-Title:after{content:""; display:block; clear:both; }
.wrapper:after{content:""; display:block; clear:both; }

What does 'git remote add upstream' help achieve?

This is useful when you have your own origin which is not upstream. In other words, you might have your own origin repo that you do development and local changes in and then occasionally merge upstream changes. The difference between your example and the highlighted text is that your example assumes you're working with a clone of the upstream repo directly. The highlighted text assumes you're working on a clone of your own repo that was, presumably, originally a clone of upstream.

What exceptions should be thrown for invalid or unexpected parameters in .NET?

Depending on the actual value and what exception fits best:

If this is not precise enough, just derive your own exception class from ArgumentException.

Yoooder's answer enlightened me. An input is invalid if it is not valid at any time, while an input is unexpected if it is not valid for the current state of the system. So in the later case an InvalidOperationException is a reasonable choice.

Java RegEx meta character (.) and ordinary dot?

I am doing some basic array in JGrasp and found that with an accessor method for a char[][] array to use ('.') to place a single dot.

Flash CS4 refuses to let go

Try deleting your ASO files.

ASO files are cached compiled versions of your class files. Although the IDE is a lot better at letting go of old caches when changes are made, sometimes you have to manually delete them. To delete ASO files: Control>Delete ASO Files.

This is also the cause of the "I-am-not-seeing-my-changes-so-let-me-add-a-trace-now-everything-works" bug that was introduced in CS3.

Maven:Non-resolvable parent POM and 'parent.relativePath' points at wrong local POM

         ` Adding the following to pom.xml will resolve the issue.      <pluginRepositories>
        <pluginRepository>
            <id>central</id>
            <name>Central Repository</name>
            <url>https://repo.maven.apache.org/maven2</url>
            <layout>default</layout>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
            <releases>
                <updatePolicy>never</updatePolicy>
            </releases>
        </pluginRepository>
   </pluginRepositories>
    
   <repositories>
        <repository>
            <id>central</id>
            <name>Central Repository</name>
            <url>https://repo.maven.apache.org/maven2</url>
            <layout>default</layout>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
   </repositories>   `

static files with express.js

res.sendFile & express.static both will work for this

var express = require('express');
var app = express();
var path = require('path');
var public = path.join(__dirname, 'public');

// viewed at http://localhost:8080
app.get('/', function(req, res) {
    res.sendFile(path.join(public, 'index.html'));
});

app.use('/', express.static(public));

app.listen(8080);

Where public is the folder in which the client side code is

As suggested by @ATOzTOA and clarified by @Vozzie, path.join takes the paths to join as arguments, the + passes a single argument to path.

JSON Structure for List of Objects

As others mentioned, Justin's answer was close, but not quite right. I tested this using Visual Studio's "Paste JSON as C# Classes"

{
    "foos" : [
        {
            "prop1":"value1",
            "prop2":"value2"
        },
        {
            "prop1":"value3", 
            "prop2":"value4"
        }
    ]
}

How to add items to a spinner in Android?

For adding item in Spinner, you can do one thing, try to create an adapter and then add/remove items into the adapter, then you can easily bind that adapter to spinner by using setAdapter() method.

Here is an example:

spinner.setAdapter(adapter);
adapter.add(item1);
adapter.add(item2);
adapter.add(item3);
adapter.add(item4);
adapter.add(item5);
adapter.notifyDataSetChanged();
spinner.setAdapter(adapter);

How do I do base64 encoding on iOS?

Better solution :

There is a built in function in NSData

[data base64Encoding]; //iOS < 7.0
[data base64EncodedStringWithOptions:NSDataBase64Encoding76CharacterLineLength]; //iOS >= 7.0

How to deserialize xml to object

The comments above are correct. You're missing the decorators. If you want a generic deserializer you can use this.

public static T DeserializeXMLFileToObject<T>(string XmlFilename)
{
    T returnObject = default(T);
    if (string.IsNullOrEmpty(XmlFilename)) return default(T);

    try
    {
        StreamReader xmlStream = new StreamReader(XmlFilename);
        XmlSerializer serializer = new XmlSerializer(typeof(T));
        returnObject = (T)serializer.Deserialize(xmlStream);
    }
    catch (Exception ex)
    {
        ExceptionLogger.WriteExceptionToConsole(ex, DateTime.Now);
    }
    return returnObject;
}

Then you'd call it like this:

MyObjType MyObj = DeserializeXMLFileToObject<MyObjType>(FilePath);

How to remove symbols from a string with Python?

I often just open the console and look for the solution in the objects methods. Quite often it's already there:

>>> a = "hello ' s"
>>> dir(a)
[ (....) 'partition', 'replace' (....)]
>>> a.replace("'", " ")
'hello   s'

Short answer: Use string.replace().

How to output to the console and file?

Create an output file and custom function:

outputFile = open('outputfile.log', 'w')

def printing(text):
    print(text)
    if outputFile:
        outputFile.write(str(text))

Then instead of print(text) in your code, call printing function.

printing("START")
printing(datetime.datetime.now())
printing("COMPLETE")
printing(datetime.datetime.now())

Using Python, how can I access a shared folder on windows network?

How did you try it? Maybe you are working with \ and omit proper escaping.

Instead of

open('\\HOST\share\path\to\file')

use either Johnsyweb's solution with the /s, or try one of

open(r'\\HOST\share\path\to\file')

or

open('\\\\HOST\\share\\path\\to\\file')

.

Does Java read integers in little endian or big endian?

There are no unsigned integers in Java. All integers are signed and in big endian.

On the C side the each byte has tne LSB at the start is on the left and the MSB at the end.

It sounds like you are using LSB as Least significant bit, are you? LSB usually stands for least significant byte. Endianness is not bit based but byte based.

To convert from unsigned byte to a Java integer:

int i = (int) b & 0xFF;

To convert from unsigned 32-bit little-endian in byte[] to Java long (from the top of my head, not tested):

long l = (long)b[0] & 0xFF;
l += ((long)b[1] & 0xFF) << 8;
l += ((long)b[2] & 0xFF) << 16;
l += ((long)b[3] & 0xFF) << 24;

What exactly is the difference between Web API and REST API in MVC?

ASP.NET Web API is a framework that makes it easy to build HTTP services that reach a broad range of clients, including browsers and mobile devices. ASP.NET Web API is an ideal platform for building RESTful applications on the .NET Framework.

REST

RESTs sweet spot is when you are exposing a public API over the internet to handle CRUD operations on data. REST is focused on accessing named resources through a single consistent interface.

SOAP

SOAP brings it’s own protocol and focuses on exposing pieces of application logic (not data) as services. SOAP exposes operations. SOAP is focused on accessing named operations, each implement some business logic through different interfaces.

Though SOAP is commonly referred to as “web services” this is a misnomer. SOAP has very little if anything to do with the Web. REST provides true “Web services” based on URIs and HTTP.

Reference: http://spf13.com/post/soap-vs-rest

And finally: What they could be referring to is REST vs. RPC See this: http://encosia.com/rest-vs-rpc-in-asp-net-web-api-who-cares-it-does-both/

Conditional Binding: if let error – Initializer for conditional binding must have Optional type

Same applies for guard statements. The same error message lead me to this post and answer (thanks @nhgrif).

The code: Print the last name of the person only if the middle name is less than four characters.

func greetByMiddleName(name: (first: String, middle: String?, last: String?)) {
    guard let Name = name.last where name.middle?.characters.count < 4 else {
        print("Hi there)")
        return
    }
    print("Hey \(Name)!")
}

Until I declared last as an optional parameter I was seeing the same error.

Convert ASCII number to ASCII Character in C

If i is the int, then

char c = i;

makes it a char. You might want to add a check that the value is <128 if it comes from an untrusted source. This is best done with isascii from <ctype.h>, if available on your system (see @Steve Jessop's comment to this answer).

Keeping ASP.NET Session Open / Alive

you can just write this code in you java script file thats it.

$(document).ready(function () {
        var delay = (20-1)*60*1000;
        window.setInterval(function () {
            var url = 'put the url of some Dummy page';
            $.get(url);                
        }, delay);
});

The (20-1)*60*1000 is refresh time, it will refresh the session timeout. Refresh timeout is calculated as default time out of iis = 20 minutes, means 20 × 60000 = 1200000 milliseconds - 60000 millisecond (One minutes before session expires ) is 1140000.

How do I add to the Windows PATH variable using setx? Having weird problems

Steps: 1. Open a command prompt with administrator's rights.

Steps: 2. Run the command: setx /M PATH "path\to;%PATH%"

[Note: Be sure to alter the command so that path\to reflects the folder path from your root.]

Example : setx /M PATH "C:\Program Files;%PATH%"

SQL Server IF NOT EXISTS Usage?

Have you verified that there is in fact a row where Staff_Id = @PersonID? What you've posted works fine in a test script, assuming the row exists. If you comment out the insert statement, then the error is raised.

set nocount on

create table Timesheet_Hours (Staff_Id int, BookedHours int, Posted_Flag bit)

insert into Timesheet_Hours (Staff_Id, BookedHours, Posted_Flag) values (1, 5.5, 0)

declare @PersonID int
set @PersonID = 1

IF EXISTS    
    (
    SELECT 1    
    FROM Timesheet_Hours    
    WHERE Posted_Flag = 1    
        AND Staff_Id = @PersonID    
    )    
    BEGIN
        RAISERROR('Timesheets have already been posted!', 16, 1)
        ROLLBACK TRAN
    END
ELSE
    IF NOT EXISTS
        (
        SELECT 1
        FROM Timesheet_Hours
        WHERE Staff_Id = @PersonID
        )
        BEGIN
            RAISERROR('Default list has not been loaded!', 16, 1)
            ROLLBACK TRAN
        END
    ELSE
        print 'No problems here'

drop table Timesheet_Hours

How to find all trigger associated with a table with SQL Server?

Go through

Need to list all triggers in SQL Server database with table name and table's schema

This URL have set of queries by which you can get the list of triggers associated with particular table.

I believe you are working in sqlserver following are the steps to get modify triggers

To modify a trigger

  1. Expand a server group, and then expand a server.

  2. Expand Databases, expand the database in which the table containing the trigger belongs, and then click Tables.

  3. In the details pane, right-click the table on which the trigger exists, point to All Tasks, and then click Manage Triggers.

  4. In Name, select the name of the trigger.

  5. Change the text of the trigger in the Text field as necessary. Press CTRL+TAB to indent the text of a SQL Server Enterprise Manager trigger.

  6. To check the syntax of the trigger, click Check Syntax.

Git: How to find a deleted file in the project commit history?

Summary:

  1. Step 1

You search your file full path in history of deleted files git log --diff-filter=D --summary | grep filename

  1. Step 2

You restore your file from commit before it was deleted

restore () {
  filepath="$@"
  last_commit=$(git log --all --full-history -- $filepath | grep commit | head -1 | awk '{print $2; exit}')
  echo "Restoring file from commit before $last_commit"
  git checkout $last_commit^ -- $filepath
}

restore my/file_path

How can I make SMTP authenticated in C#

In my case even after following all of the above. I had to upgrade my project from .net 3.5 to .net 4 to authorize against our internal exchange 2010 mail server.

Python: print a generator expression?

You can just wrap the expression in a call to list:

>>> list(x for x in string.letters if x in (y for y in "BigMan on campus"))
['a', 'c', 'g', 'i', 'm', 'n', 'o', 'p', 's', 'u', 'B', 'M']

Read a text file using Node.js?

The async way of life:

#! /usr/bin/node

const fs = require('fs');

function readall (stream)
{
  return new Promise ((resolve, reject) => {
    const chunks = [];
    stream.on ('error', (error) => reject (error));
    stream.on ('data',  (chunk) => chunk && chunks.push (chunk));
    stream.on ('end',   ()      => resolve (Buffer.concat (chunks)));
  });
}

function readfile (filename)
{
  return readall (fs.createReadStream (filename));
}

(async () => {
  let content = await readfile ('/etc/ssh/moduli').catch ((e) => {})
  if (content)
    console.log ("size:", content.length,
                 "head:", content.slice (0, 46).toString ());
})();

Specific Time Range Query in SQL Server

I (using PostgrSQL on PGadmin4) queried for results that are after or on 21st Nov 2017 at noon, like this (considering the display format of hours on my database):

select * from Table1 where FIELD >='2017-11-21 12:00:00' 

Where does flask look for image files?

for importing the image in flask you want a sub folder named static into the folder keep your img

and go into your html file and write

Converting a pointer into an integer

Use intptr_t and uintptr_t.

To ensure it is defined in a portable way, you can use code like this:

#if defined(__BORLANDC__)
    typedef unsigned char uint8_t;
    typedef __int64 int64_t;
    typedef unsigned long uintptr_t;
#elif defined(_MSC_VER)
    typedef unsigned char uint8_t;
    typedef __int64 int64_t;
#else
    #include <stdint.h>
#endif

Just place that in some .h file and include wherever you need it.

Alternatively, you can download Microsoft’s version of the stdint.h file from here or use a portable one from here.

MySQL: Can't create table (errno: 150)

You can get the actual error message by running SHOW ENGINE INNODB STATUS; and then looking for LATEST FOREIGN KEY ERROR in the output.

Source: answer from another user in a similar question

Visual Studio loading symbols

Visual Studio 2017 Debug symbol "speed-up" options, assuming you haven't gone crazy on option-customization already:

  1. At Tools -> Options -> Debugging -> Symbols
    a. Enable the "Microsoft Symbol Server" option
    b. Click "Empty Symbol Cache"
    c. Set your symbol cache to an easy to find spot, like C:\dbg_symbols or %USERPROFILE%\dbg_symbols
  2. After re-running Debug, let it load all the symbols once, from start-to-end, or as much as reasonably possible.

1A and 2 are the most important steps. 1B and 1C are just helpful changes to help you keep track of your symbols.

After your app has loaded all the symbols at least once and debugging didn't prematurely terminate, those symbols should be quickly loaded the next time debug runs.

I've noticed that if I cancel a debug-run, I have to reload those symbols, as I'm guessing they're "cleaned" up if newly introduced and suddenly cancelled. I understand the core rationale for that kind of flow, but in this case it seems poorly thought out.

How to downgrade tensorflow, multiple versions possible?

If you have anaconda, you can just install desired version and conda will automatically downgrade the current package for you.

For example:

conda install tensorflow=1.1

Swift Bridging Header import issue

for others who have troubles to add swift class into objective-c project. this is what work for me :

  1. create NEW swift file. this will make xcode to prompt if you want xcode to create all settings for mix swift-objective-c project including brigde-header.h for you. press yes.
  2. now, add your existing swift files you want to use in your project.
  3. in the implementation file you are going to use the swift class add : #import "YOURPROJECTNAME-swift.h" . this file xcode create for you. if your xcode project is myProject then "myProject-swift.h"

and that's it. now create the swift class in your code like it was objective-c.

How to add property to object in PHP >= 5.3 strict mode without generating error

I don't know whether its the newer version of php, but this works. I'm using php 5.6

    <?php
    class Person
    {
       public $name;

       public function save()
       {
          print_r($this);
       }
    }

   $p = new Person;
   $p->name = "Ganga";
   $p->age = 23;

   $p->save();

This is the result. The save method actually gets the new property

    Person Object
    (
       [name] => Ganga
       [age] => 23
    )

How to git reset --hard a subdirectory?

For the case of simply discarding changes, the git checkout -- path/ or git checkout HEAD -- path/ commands suggested by other answers work great. However, when you wish to reset a directory to a revision other than HEAD, that solution has a significant problem: it doesn't remove files which were deleted in the target revision.

So instead, I have begun using the following command:

git diff --cached commit -- subdir | git apply -R --index

This works by finding the diff between the target commit and the index, then applying that diff in reverse to the working directory and index. Basically, this means that it makes the contents of the index match the contents of the revision you specified. The fact that git diff takes a path argument allows you to limit this effect to a specific file or directory.

Since this command fairly long and I plan on using it frequently, I have set up an alias for it which I named reset-checkout:

git config --global alias.reset-checkout '!f() { git diff --cached "$@" | git apply -R --index; }; f'

You can use it like this:

git reset-checkout 451a9a4 -- path/to/directory

Or just:

git reset-checkout 451a9a4

How to get the sign, mantissa and exponent of a floating point number

Cast a pointer to the floating point variable as something like an unsigned int. Then you can shift and mask the bits to get each component.

float foo;
unsigned int ival, mantissa, exponent, sign;

foo = -21.4f;
ival = *((unsigned int *)&foo);
mantissa = ( ival & 0x7FFFFF);
ival = ival >> 23;
exponent = ( ival  & 0xFF );
ival = ival >> 8;
sign = ( ival & 0x01 );

Obviously you probably wouldn't use unsigned ints for the exponent and sign bits but this should at least give you the idea.

Docker: How to use bash with an Alpine based docker image?

To Install bash you can do:

RUN apk add --update bash && rm -rf /var/cache/apk/*

If you do not want to add extra size to your image, you can use ash or sh that ships with alpine.

Reference: https://github.com/smebberson/docker-alpine/issues/43

How do I initialize Kotlin's MutableList to empty MutableList?

You can simply write:

val mutableList = mutableListOf<Kolory>()

This is the most idiomatic way.

Alternative ways are

val mutableList : MutableList<Kolory> = arrayListOf()

or

val mutableList : MutableList<Kolory> = ArrayList()

This is exploiting the fact that java types like ArrayList are implicitly implementing the type MutableList via a compiler trick.

How to display pdf in php

easy if its pdf or img use

return (in_Array($file['content-type'], ['image/jpg', 'application/pdf']));

Multiple variables in a 'with' statement?

In Python 3.1+ you can specify multiple context expressions, and they will be processed as if multiple with statements were nested:

with A() as a, B() as b:
    suite

is equivalent to

with A() as a:
    with B() as b:
        suite

This also means that you can use the alias from the first expression in the second (useful when working with db connections/cursors):

with get_conn() as conn, conn.cursor() as cursor:
    cursor.execute(sql)

C# Convert a Base64 -> byte[]

This may be helpful

byte[] bytes = System.Convert.FromBase64String(stringInBase64);

Netbeans - Error: Could not find or load main class

Just close the Netbeans. Go to C:\Users\YOUR_PC_NAME\AppData\Local\Netbeans and delete the Cache folder. The open the Netbeans again and run the project. It works like magic for me.

(AppData folder might be hidden probably, if so, you need to make it appear in Folder Options).enter image description here

What characters do I need to escape in XML documents?

Abridged from: XML, Escaping

There are five predefined entities:

&lt; represents "<"
&gt; represents ">"
&amp; represents "&"
&apos; represents '
&quot; represents "

"All permitted Unicode characters may be represented with a numeric character reference." For example:

&#20013;

Most of the control characters and other Unicode ranges are specifically excluded, meaning (I think) they can't occur either escaped or direct:

Valid characters in XML

Update some specific field of an entity in android Room

after trying to fix a similar problem my self, where I had changed from @PrimaryKey(autoGenerate = true) to int UUID, I couldn't find how to write my migration so I changed the table name, it's an easy fix, and ok if you working with a personal/small app

Getting the docstring from a function

On ipython or jupyter notebook, you can use all the above mentioned ways, but i go with

my_func?

or

?my_func

for quick summary of both method signature and docstring.

I avoid using

my_func??

(as commented by @rohan) for docstring and use it only to check the source code

DateTime group by date and hour

SELECT [activity_dt], COUNT(*) as [Count]
  FROM 
 (SELECT dateadd(hh, datediff(hh, '20010101', [activity_dt]), '20010101') as [activity_dt]
    FROM table) abc
 GROUP BY [activity_dt]

Arguments to main in C

Imagine it this way

*main() is also a function which is called by something else (like another FunctioN)

*the arguments to it is decided by the FunctioN

*the second argument is an array of strings

*the first argument is a number representing the number of strings

*do something with the strings

Maybe a example program woluld help.

int main(int argc,char *argv[])
{

    printf("you entered in reverse order:\n");

    while(argc--)
    {
        printf("%s\n",argv[argc]);
    }

return 0;
}

it just prints everything you enter as args in reverse order but YOU should make new programs that do something more useful.

compile it (as say hello) run it from the terminal with the arguments like

./hello am i here

then try to modify it so that it tries to check if two strings are reverses of each other or not then you will need to check if argc parameter is exactly three if anything else print an error

if(argc!=3)/*3 because even the executables name string is on argc*/
{
    printf("unexpected number of arguments\n");
    return -1;
}

then check if argv[2] is the reverse of argv[1] and print the result

./hello asdf fdsa

should output

they are exact reverses of each other

the best example is a file copy program try it it's like cp

cp file1 file2

cp is the first argument (argv[0] not argv[1]) and mostly you should ignore the first argument unless you need to reference or something

if you made the cp program you understood the main args really...

T-SQL How to create tables dynamically in stored procedures?

This is a way to create tables dynamically using T-SQL stored procedures:

declare @cmd nvarchar(1000), @MyTableName nvarchar(100);
set @MyTableName = 'CustomerDetails';
set @cmd = 'CREATE TABLE dbo.' + quotename(@MyTableName, '[') + '(ColumnName1 int not null,ColumnName2 int not null);';

Execute it as:

exec(@cmd);

JQuery html() vs. innerHTML

Here is some code to get you started. You can modify the behavior of .innerHTML -- you could even create your own complete .innerHTML shim. (P.S.: redefining .innerHTML will also work in Firefox, but not Chrome -- they're working on it.)

if (/(msie|trident)/i.test(navigator.userAgent)) {
 var innerhtml_get = Object.getOwnPropertyDescriptor(HTMLElement.prototype, "innerHTML").get
 var innerhtml_set = Object.getOwnPropertyDescriptor(HTMLElement.prototype, "innerHTML").set
 Object.defineProperty(HTMLElement.prototype, "innerHTML", {
  get: function () {return innerhtml_get.call (this)},
  set: function(new_html) {
   var childNodes = this.childNodes
   for (var curlen = childNodes.length, i = curlen; i > 0; i--) {
    this.removeChild (childNodes[0])
   }
   innerhtml_set.call (this, new_html)
  }
 })
}

var mydiv = document.createElement ('div')
mydiv.innerHTML = "test"
document.body.appendChild (mydiv)

document.body.innerHTML = ""
console.log (mydiv.innerHTML)

http://jsfiddle.net/DLLbc/9/

How to make a div 100% height of the browser window

If you want to set the height of a <div> or any element, you should set the height of <body> and <html> to 100% too. Then you can set the height of element with 100% :)

Here is an example:

body, html {
  height: 100%;
}

#right {
  height: 100%;
}

Is there a way to make a DIV unselectable?

Also in IOS if you want to get rid of gray semi-transparent overlays appearing ontouch, add css:

-webkit-tap-highlight-color: rgba(0,0,0,0);
-webkit-touch-callout: none;

What are all the uses of an underscore in Scala?

Here are some more examples where _ is used:

val nums = List(1,2,3,4,5,6,7,8,9,10)

nums filter (_ % 2 == 0)

nums reduce (_ + _)

nums.exists(_ > 5)

nums.takeWhile(_ < 8)

In all above examples one underscore represents an element in the list (for reduce the first underscore represents the accumulator)

How does "make" app know default target to build if no target is specified?

To save others a few seconds, and to save them from having to read the manual, here's the short answer. Add this to the top of your make file:

.DEFAULT_GOAL := mytarget

mytarget will now be the target that is run if "make" is executed and no target is specified.

If you have an older version of make (<= 3.80), this won't work. If this is the case, then you can do what anon mentions, simply add this to the top of your make file:

.PHONY: default
default: mytarget ;

References: https://www.gnu.org/software/make/manual/html_node/How-Make-Works.html

Custom method names in ASP.NET Web API

I am days into the MVC4 world.

For what its worth, I have a SitesAPIController, and I needed a custom method, that could be called like:

http://localhost:9000/api/SitesAPI/Disposition/0

With different values for the last parameter to get record with different dispositions.

What Finally worked for me was:

The method in the SitesAPIController:

// GET api/SitesAPI/Disposition/1
[ActionName("Disposition")]
[HttpGet]
public Site Disposition(int disposition)
{
    Site site = db.Sites.Where(s => s.Disposition == disposition).First();
    return site;
}

And this in the WebApiConfig.cs

// this was already there
config.Routes.MapHttpRoute(
    name: "DefaultApi",
    routeTemplate: "api/{controller}/{id}",
    defaults: new { id = RouteParameter.Optional }
);

// this i added
config.Routes.MapHttpRoute(
    name: "Action",
    routeTemplate: "api/{controller}/{action}/{disposition}"
 );

For as long as I was naming the {disposition} as {id} i was encountering:

{
"Message": "No HTTP resource was found that matches the request URI 'http://localhost:9000/api/SitesAPI/Disposition/0'.",
"MessageDetail": "No action was found on the controller 'SitesAPI' that matches the request."
}

When I renamed it to {disposition} it started working. So apparently the parameter name is matched with the value in the placeholder.

Feel free to edit this answer to make it more accurate/explanatory.

Increasing nesting function calls limit

Personally I would suggest this is an error as opposed to a setting that needs adjusting. In my code it was because I had a class that had the same name as a library within one of my controllers and it seemed to trip it up.

Output errors and see where this is being triggered.

How do I install PHP cURL on Linux Debian?

Whatever approach you take, make sure in the end that you have an updated version of curl and libcurl. You can do curl --version and see the versions.

Here's what I did to get the latest curl version installed in Ubuntu:

  1. sudo add-apt-repository "deb http://mirrors.kernel.org/ubuntu wily main"
  2. sudo apt-get update
  3. sudo apt-get install curl

Set scroll position

... Or just replace body by documentElement:

document.documentElement.scrollTop = 0;

php_network_getaddresses: getaddrinfo failed: Name or service not known

I was getting the same error of fsocket() and I just updated my hosts files

  1. I logged via SSH in CentOS server. USERNAME and PASSWORD type
  2. cd /etc/
  3. ls                                     //"just to watch list"
  4. vi hosts                                   //"edit the host file"
  5. i                                    //" to put the file into insert mode"
  6. 95.183.24.10                 [mail_server_name] in my case ("mail.kingologic.com")
  7. Press ESC Key
  8. press ZZ

hope it will solve your problem

for any further query please ping me at http://kingologic.com

How to make an image center (vertically & horizontally) inside a bigger div

Here try this out.

_x000D_
_x000D_
.parentdiv {_x000D_
 height: 400px;_x000D_
 border: 2px solid #cccccc;_x000D_
  background: #efefef;_x000D_
 position: relative;_x000D_
}_x000D_
.childcontainer {_x000D_
 position: absolute;_x000D_
 left: 50%;_x000D_
 top: 50%;_x000D_
}_x000D_
.childdiv {_x000D_
 width: 150px;_x000D_
 height:150px;_x000D_
 background: lightgreen;_x000D_
 border-radius: 50%;_x000D_
 border: 2px solid green;_x000D_
 margin-top: -50%;_x000D_
 margin-left: -50%;_x000D_
}
_x000D_
<div class="parentdiv">_x000D_
  <div class="childcontainer">_x000D_
     <div class="childdiv">_x000D_
     </div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

HTTP response header content disposition for attachments

neither use inline; nor attachment; just use

response.setContentType("text/xml");
response.setHeader( "Content-Disposition", "filename=" + filename );

or

response.setHeader( "Content-Disposition", "filename=\"" + filename + "\"" );

or

response.setHeader( "Content-Disposition", "filename=\"" + 
  filename.substring(0, filename.lastIndexOf('.')) + "\"");

simple way to display data in a .txt file on a webpage?

That's the code I use:

<?php   
    $path="C:/foopath/";
    $file="foofile.txt";

    //read file contents
    $content="
        <h2>$file</h2>
            <code>
                <pre>".htmlspecialchars(file_get_contents("$path/$file"))."</pre>
            </code>";

    //display
    echo $content;
?>

Keep in mind that if the user can modify $path or $file (for example via $_GET or $_POST), he/she will be able to see all your source files (danger!)

Error: Failed to lookup view in Express

You could set the path to a constant like this and set it using express.

const viewsPath = path.join(__dirname, '../views') 
app.set('view engine','hbs')

 app.set('views', viewsPath)

 app.get('/', function(req, res){

 res.render("index");

});

This worked for me

An URL to a Windows shared folder

If you are allowed to go further then javascript/html facilities - I would use the apache web server to represent your directory listing via http.

If this solution is appropriate. these are the steps:

  1. download apache hhtp server from one of the mirrors http://httpd.apache.org/download.cgi

  2. unzip/install (if msi) it to the directory e.g C:\opt\Apache (the instruction is for windows)

  3. map the network forlder as a local drive on windows (\server\folder to let's say drive H:)

  4. open conf/httpd.conf file

  5. make sure the next line is present and not commented

    LoadModule autoindex_module modules/mod_autoindex.so

  6. Add directory configuration

<Directory "H:/path">

Options +Indexes

AllowOverride None

Order allow,deny

Allow from all

</Directory> 7. Start the web server and make sure the directory listingof the remote folder is available by http. hit localhost/path 8. use a frame inside your web page to access the listing

What is missed: 1. you mignt need more fancy configuration for the host name, refer to Apache Web Server docs. Register the host name in DNS server

  1. the mapping to the network drive might not work, i did not check. As a posible resolution - host your web server on the same machine as smb server.

Bootstrap 3 dropdown select

We just switched our site to bootstrap 3 and we have a bunch of forms...wasn't fun but once you get the hang it's not too bad.

Is this what you are looking for? Demo Here

<div class="form-group">
  <label class="control-label col-sm-offset-2 col-sm-2" for="company">Company</label>
  <div class="col-sm-6 col-md-4">
    <select id="company" class="form-control">
      <option>small</option>
      <option>medium</option>
      <option>large</option>
    </select> 
  </div>
</div>

How do I open a URL from C++?

I've had MUCH better luck using ShellExecuteA(). I've heard that there are a lot of security risks when you use "system()". This is what I came up with for my own code.

void SearchWeb( string word )
{    
    string base_URL = "http://www.bing.com/search?q=";
    string search_URL = "dummy";
    search_URL = base_URL + word;

    cout << "Searching for: \"" << word << "\"\n";

    ShellExecuteA(NULL, "open", search_URL.c_str(), NULL, NULL, SW_SHOWNORMAL);
}

p.s. Its using WinAPI if i'm correct. So its not multiplatform solution.

Conversion failed when converting the varchar value to data type int in sql

Your problem seams to be located here:

SELECT @maxCode = CAST(MAX(CAST(SUBSTRING(Voucher_No,LEN(@startFrom)+1,LEN(Voucher_No)- LEN(@Prefix)) AS INT)) AS varchar(100)) FROM dbo.Journal_Entry;
SET @sCode=CAST(@maxCode AS INT)

As the error says, you're casting a string that contains a letter 'J' to an INT which for obvious reasons is not possible.

Either fix SUBSTRING or don't store the letter 'J' in the database and only prepend it when reading.

Why am I getting a " Traceback (most recent call last):" error?

At the beginning of your file you set raw_input to 0. Do not do this, at it modifies the built-in raw_input() function. Therefore, whenever you call raw_input(), it is essentially calling 0(), which raises the error. To remove the error, remove the first line of your code:

M = 1.6
# Miles to Kilometers 
# Celsius Celsius = (var1 - 32) * 5/9
# Gallons to liters Gallons = 3.6
# Pounds to kilograms Pounds = 0.45
# Inches to centimete Inches = 2.54


def intro():
    print("Welcome! This program will convert measures for you.")
    main()

def main():
    print("Select operation.")
    print("1.Miles to Kilometers")
    print("2.Fahrenheit to Celsius")
    print("3.Gallons to liters")
    print("4.Pounds to kilograms")
    print("5.Inches to centimeters")

    choice = input("Enter your choice by number: ")

    if choice == '1':
        convertMK()

    elif choice == '2':
        converCF()

    elif choice == '3':
        convertGL()

    elif choice == '4':
        convertPK()

    elif choice == '5':
        convertPK()

    else:
        print("Error")


def convertMK():
    input_M = float(raw_input(("Miles: ")))
    M_conv = (M) * input_M
    print("Kilometers: %f\n" % M_conv)
    restart = str(input("Do you wish to make another conversion? [y]Yes or [n]no: "))
    if restart == 'y':
        main()
    elif restart == 'n':
        end()
    else:
        print("I didn't quite understand that answer. Terminating.")
        main()

def converCF():
    input_F = float(raw_input(("Fahrenheit: ")))
    F_conv = (input_F - 32) * 5/9
    print("Celcius: %f\n") % F_conv
    restart = str(input("Do you wish to make another conversion? [y]Yes or [n]no: "))
    if restart == 'y':
        main()
    elif restart == 'n':
        end()
    else:
        print("I didn't quite understand that answer. Terminating.")
        main()

def convertGL():
    input_G = float(raw_input(("Gallons: ")))
    G_conv = input_G * 3.6
    print("Centimeters: %f\n" % G_conv)
    restart = str(input("Do you wish to make another conversion? [y]Yes or [n]no: "))
    if restart == 'y':
        main()
    elif restart == 'n':
        end()
    else:
        print ("I didn't quite understand that answer. Terminating.")
        main()

def convertPK():
    input_P = float(raw_input(("Pounds: ")))
    P_conv = input_P * 0.45
    print("Centimeters: %f\n" % P_conv)
    restart = str(input("Do you wish to make another conversion? [y]Yes or [n]no: "))
    if restart == 'y':
        main()
    elif restart == 'n':
        end()
    else:
        print ("I didn't quite understand that answer. Terminating.")
        main()

def convertIC():
    input_cm = float(raw_input(("Inches: ")))
    inches_conv = input_cm * 2.54
    print("Centimeters: %f\n" % inches_conv)
    restart = str(input("Do you wish to make another conversion? [y]Yes or [n]no: "))
    if restart == 'y':
        main()
    elif restart == 'n':
        end()
    else:
        print ("I didn't quite understand that answer. Terminating.")
        main()

def end():
    print("This program will close.")
    exit()

intro()

How to cast an Object to an int

If the Object was originally been instantiated as an Integer, then you can downcast it to an int using the cast operator (Subtype).

Object object = new Integer(10);
int i = (Integer) object;

Note that this only works when you're using at least Java 1.5 with autoboxing feature, otherwise you have to declare i as Integer instead and then call intValue() on it.

But if it initially wasn't created as an Integer at all, then you can't downcast like that. It would result in a ClassCastException with the original classname in the message. If the object's toString() representation as obtained by String#valueOf() denotes a syntactically valid integer number (e.g. digits only, if necessary with a minus sign in front), then you can use Integer#valueOf() or new Integer() for this.

Object object = "10";
int i = Integer.valueOf(String.valueOf(object));

See also:

comparing strings in vb

I would suggest using the String.Compare method. Using that method you can also control whether to to have it perform case-sensitive comparisons or not.

Sample:

Dim str1 As String = "String one"
Dim str2 As String = str1
Dim str3 As String = "String three"
Dim str4 As String = str3

If String.Compare(str1, str2) = 0 And String.Compare(str3, str4) = 0 Then
    MessageBox.Show("str1 = str2 And str3 = str4")
Else
    MessageBox.Show("Else")
End If

Edit: if you want to perform a case-insensitive search you can use the StringComparison parameter:

If String.Compare(str1, str2, StringComparison.InvariantCultureIgnoreCase) = 0 And String.Compare(str3, str4, StringComparison.InvariantCultureIgnoreCase) = 0 Then

How do I make a fully statically linked .exe with Visual Studio Express 2005?

In regards Jared's response, having Windows 2000 or better will not necessarily fix the issue at hand. Rob's response does work, however it is possible that this fix introduces security issues, as Windows updates will not be able to patch applications built as such.

In another post, Nick Guerrera suggests packaging the Visual C++ Runtime Redistributable with your applications, which installs quickly, and is independent of Visual Studio.

What is the perfect counterpart in Python for "while not EOF"

While there are suggestions above for "doing it the python way", if one wants to really have a logic based on EOF, then I suppose using exception handling is the way to do it --

try:
    line = raw_input()
    ... whatever needs to be done incase of no EOF ...
except EOFError:
    ... whatever needs to be done incase of EOF ...

Example:

$ echo test | python -c "while True: print raw_input()"
test
Traceback (most recent call last):
  File "<string>", line 1, in <module> 
EOFError: EOF when reading a line

Or press Ctrl-Z at a raw_input() prompt (Windows, Ctrl-Z Linux)

Iterating a JavaScript object's properties using jQuery

Note: Most modern browsers will now allow you to navigate objects in the developer console. This answer is antiquated.

This method will walk through object properties and write them to the console with increasing indent:

function enumerate(o,s){

    //if s isn't defined, set it to an empty string
    s = typeof s !== 'undefined' ? s : "";

    //if o is null, we need to output and bail
    if(typeof o == "object" && o === null){

       console.log(s+k+": null");

    } else {    

        //iterate across o, passing keys as k and values as v
        $.each(o, function(k,v){

            //if v has nested depth
           if(typeof v == "object" && v !== null){

                //write the key to the console
                console.log(s+k+": ");

                //recursively call enumerate on the nested properties
                enumerate(v,s+"  ");

            } else {

                //log the key & value
                console.log(s+k+": "+String(v));
            }
        });
    }
}

Just pass it the object you want to iterate through:

    var response = $.ajax({
        url: myurl,
        dataType: "json"
    })
    .done(function(a){
       console.log("Returned values:");
       enumerate(a);
    })
    .fail(function(){ console.log("request failed");});

Error Installing Homebrew - Brew Command Not Found

You can use this:

ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)" 

to install homebrew.

Django DateField default options

This should do the trick:

models.DateTimeField(_("Date"), auto_now_add = True)

How to check if any value is NaN in a Pandas DataFrame

To find out which rows have NaNs in a specific column:

nan_rows = df[df['name column'].isnull()]

How does MySQL CASE work?

CASE is more like a switch statement. It has two syntaxes you can use. The first lets you use any compare statements you want:

CASE 
    WHEN user_role = 'Manager' then 4
    WHEN user_name = 'Tom' then 27
    WHEN columnA <> columnB then 99
    ELSE -1 --unknown
END

The second style is for when you are only examining one value, and is a little more succinct:

CASE user_role
    WHEN 'Manager' then 4
    WHEN 'Part Time' then 7
    ELSE -1 --unknown
END

How to set value to variable using 'execute' in t-sql?

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- =============================================
-- Author:      Andrew Foster
-- Create date: 28 Mar 2013
-- Description: Allows the dynamic pull of any column value up to 255 chars from regUsers table
-- =============================================
ALTER PROCEDURE dbo.PullTableColumn
(
    @columnName varchar(255),
    @id int
)
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    DECLARE @columnVal TABLE (columnVal nvarchar(255));

    DECLARE @sql nvarchar(max);
    SET @sql = 'SELECT ' + @columnName + ' FROM regUsers WHERE id=' + CAST(@id AS varchar(10));
    INSERT @columnVal EXEC sp_executesql @sql;

    SELECT * FROM @columnVal;
END
GO

How to enable scrolling of content inside a modal?

I had the same issue, and found a fix as below:

$('.yourModalClassOr#ID').on('shown.bs.modal', function (e) {
    $(' yourModalClassOr#ID ').css("max-height", $(window).height());
    $(' yourModalClassOr#ID ').css("overflow-y", "scroll");          /*Important*/
    $(' yourModalClassOr#ID ').modal('handleUpdate');

});

100% working.

Spring MVC: Complex object as GET @RequestParam

I have a very similar problem. Actually the problem is deeper as I thought. I am using jquery $.post which uses Content-Type:application/x-www-form-urlencoded; charset=UTF-8 as default. Unfortunately I based my system on that and when I needed a complex object as a @RequestParam I couldn't just make it happen.

In my case I am trying to send user preferences with something like;

 $.post("/updatePreferences",  
    {id: 'pr', preferences: p}, 
    function (response) {
 ...

On client side the actual raw data sent to the server is;

...
id=pr&preferences%5BuserId%5D=1005012365&preferences%5Baudio%5D=false&preferences%5Btooltip%5D=true&preferences%5Blanguage%5D=en
...

parsed as;

id:pr
preferences[userId]:1005012365
preferences[audio]:false
preferences[tooltip]:true
preferences[language]:en

and the server side is;

@RequestMapping(value = "/updatePreferences")
public
@ResponseBody
Object updatePreferences(@RequestParam("id") String id, @RequestParam("preferences") UserPreferences preferences) {

    ...
        return someService.call(preferences);
    ...
}

I tried @ModelAttribute, added setter/getters, constructors with all possibilities to UserPreferences but no chance as it recognized the sent data as 5 parameters but in fact the mapped method has only 2 parameters. I also tried Biju's solution however what happens is that, spring creates an UserPreferences object with default constructor and doesn't fill in the data.

I solved the problem by sending JSon string of the preferences from the client side and handle it as if it is a String on the server side;

client:

 $.post("/updatePreferences",  
    {id: 'pr', preferences: JSON.stringify(p)}, 
    function (response) {
 ...

server:

@RequestMapping(value = "/updatePreferences")
public
@ResponseBody
Object updatePreferences(@RequestParam("id") String id, @RequestParam("preferences") String preferencesJSon) {


        String ret = null;
        ObjectMapper mapper = new ObjectMapper();
        try {
            UserPreferences userPreferences = mapper.readValue(preferencesJSon, UserPreferences.class);
            return someService.call(userPreferences);
        } catch (IOException e) {
            e.printStackTrace();
        }
}

to brief, I did the conversion manually inside the REST method. In my opinion the reason why spring doesn't recognize the sent data is the content-type.

Using OpenGl with C#?

OpenTK is an improvement over the Tao API, as it uses idiomatic C# style with overloading, strongly-typed enums, exceptions, and standard .NET types:

GL.Begin(BeginMode.Points);
GL.Color3(Color.Yellow);
GL.Vertex3(Vector3.Up);

as opposed to Tao which merely mirrors the C API:

Gl.glBegin(Gl.GL_POINTS);   // double "gl" prefix
Gl.glColor3ub(255, 255, 0); // have to pass RGB values as separate args
Gl.glVertex3f(0, 1, 0);     // explicit "f" qualifier

This makes for harder porting but is incredibly nice to use.

As a bonus it provides font rendering, texture loading, input handling, audio, math...

Update 18th January 2016: Today the OpenTK maintainer has stepped away from the project, leaving its future uncertain. The forums are filled with spam. The maintainer recommends moving to MonoGame or SDL2#.

Update 30th June 2020: OpenTK has had new maintainers for a while now and has an active discord community. So the previous recommendation of using another library isn't necessarily true.

How to set up default schema name in JPA configuration?

If you are using (org.springframework.jdbc.datasource.DriverManagerDataSource) in ApplicationContext.xml to specify Database details then use below simple property to specify the schema.

<property name="schema" value="schemaName" />

Bootstrap 3 unable to display glyphicon properly

Here's the fix that worked for me. Firefox has a file origin policy that causes this. To fix do the following steps:

  1. open about:config in firefox
  2. Find security.fileuri.strict_origin_policy property and change it from ‘true’ to ‘false.’
  3. Voial! you are good to go!

Details: http://stuffandnonsense.co.uk/blog/about/firefoxs_file_uri_origin_policy_and_web_fonts

You will only see this issue when accessing a file using file:/// protocol

ORA-01882: timezone region not found

I was able to solve the same issue by setting the timezone in my linux system (Centos6.5).

Reposting from

http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/set-time.html

  1. set timezone in /etc/sysconfig/clock e.g. set to ZONE="America/Los_Angeles"

  2. sudo ln -sf /usr/share/zoneinfo/America/Phoenix /etc/localtime

To figure out the timezone value try to

ls /usr/share/zoneinfo

and look for the file that represents your timezone.

Once you've set these reboot the machine and try again.

Keep SSH session alive

The ssh daemon (sshd), which runs server-side, closes the connection from the server-side if the client goes silent (i.e., does not send information). To prevent connection loss, instruct the ssh client to send a sign-of-life signal to the server once in a while.

The configuration for this is in the file $HOME/.ssh/config, create the file if it does not exist (the config file must not be world-readable, so run chmod 600 ~/.ssh/config after creating the file). To send the signal every e.g. four minutes (240 seconds) to the remote host, put the following in that configuration file:

Host remotehost
    HostName remotehost.com
    ServerAliveInterval 240

To enable sending a keep-alive signal for all hosts, place the following contents in the configuration file:

Host *
    ServerAliveInterval 240

Android Color Picker

After some searches in the android references, the newcomer QuadFlask Color Picker seems to be a technically and aesthetically good choice. Also it has Transparency slider and supports HEX coded colors.

Take a look:
QuadFlask Color Picker

Are Git forks actually Git clones?

"Fork" in this context means "Make a copy of their code so that I can add my own modifications". There's not much else to say. Every clone is essentially a fork, and it's up to the original to decide whether to pull the changes from the fork.

npm ERR! Error: EPERM: operation not permitted, rename

Trying to rename a file to another filename that already exists can cause an EPERM error on Windows.

Converting NSString to NSDate (and back again)

The above examples aren't simply written for Swift 3.0+

Update - Swift 3.0+ - Convert Date To String

let date = Date() // insert your date data here
var dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd" // add custom format if you'd like 
var dateString = dateFormatter.string(from: date)

JSON and escaping characters

hmm, well here's a workaround anyway:

function JSON_stringify(s, emit_unicode)
{
   var json = JSON.stringify(s);
   return emit_unicode ? json : json.replace(/[\u007f-\uffff]/g,
      function(c) { 
        return '\\u'+('0000'+c.charCodeAt(0).toString(16)).slice(-4);
      }
   );
}

test case:

js>s='15\u00f8C 3\u0111';
15°C 3?
js>JSON_stringify(s, true)
"15°C 3?"
js>JSON_stringify(s, false)
"15\u00f8C 3\u0111"

Error Code 1292 - Truncated incorrect DOUBLE value - Mysql

If you don't have double value field or data, maybe you should try to disable sql strict mode.

To do that you have to edit "my.ini" file located in MySQL installation folder, find "Set the SQL mode to strict" line and change the below line:

# Set the SQL mode to strict
sql-mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"

to this, deleting "STRICT_TRANS_TABLES"

# Set the SQL mode to strict
sql-mode="NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"

After that, you have to restart MySQL service to enable this change.

To check the change, open the editor an execute this sql sentence:

SHOW VARIABLES LIKE 'sql_mode';

Very Important: Be careful of the file format after saving. Save it as "UTF8" and don't as "TFT8 with BOM" because the service will not restart.

Fatal error: Out of memory, but I do have plenty of memory (PHP)

I would guess that you either haven't edited the right php.ini or you haven't restarted PHP and/or the webserver.

Create a phpinfo.php page in your docroot with the contents <?php phpinfo(); to make sure you are changing the correct php.ini. In addition to the location of the php.ini file the webserver is using, it will also state the maximum script memory allowed.

Next, I would add some stack traces to your page so you can see the chain of events that led to this. The following function will catch fatal errors and provide more information about what happened.

register_shutdown_function(function()
{
    if($error = error_get_last())
    {
        // Should actually log this instead of printing out...
        var_dump($error);
        var_dump(debug_backtrace());
    }
});

Personally, Nginx + PHP-FPM is what I have used for years since I left slow ol' Apache.

Using global variables in a function

In case you have a local variable with the same name, you might want to use the globals() function.

globals()['your_global_var'] = 42

can't load package: package .: no buildable Go source files

Another possible reason for the message:

can't load package: .... : no buildable Go source files

Is when the source files being compiled have:

// +build ignore

In which case the files are ignored and not buildable as requested.This behaviour is documented at https://golang.org/pkg/go/build/

Component based game engine design

I researched and implemented this last semester for a game development course. Hopefully this sample code can point you in the right direction of how you might approach this.

class Entity {
public:
    Entity(const unsigned int id, const std::string& enttype);
    ~Entity();

    //Component Interface
    const Component* GetComponent(const std::string& family) const;
    void SetComponent(Component* newComp);
    void RemoveComponent(const std::string& family);
    void ClearComponents();

    //Property Interface
    bool HasProperty(const std::string& propName) const;
    template<class T> T& GetPropertyDataPtr(const std::string& propName);
    template<class T> const T& GetPropertyDataPtr(const std::string& propName) const;

    //Entity Interface
    const unsigned int GetID() const;
    void Update(float dt);

private:
    void RemoveProperty(const std::string& propName);
    void ClearProperties();
    template<class T> void AddProperty(const std::string& propName);
    template<class T> Property<T>* GetProperty(const std::string& propName);
    template<class T> const Property<T>* GetProperty(const std::string& propName) const;

    unsigned int m_Id;
    std::map<const string, IProperty*> m_Properties;
    std::map<const string, Component*> m_Components;
};

Components specify behavior and operate on properties. Properties are shared between all components by a reference and get updates for free. This means no large overhead for message passing. If there's any questions I'll try to answer as best I can.

Python: How to increase/reduce the fontsize of x and y tick labels?

One shouldn't use set_yticklabels to change the fontsize, since this will also set the labels (i.e. it will replace any automatic formatter by a FixedFormatter), which is usually undesired. The easiest is to set the respective tick_params:

ax.tick_params(axis="x", labelsize=8)
ax.tick_params(axis="y", labelsize=20)

or

ax.tick_params(labelsize=8)

in case both axes shall have the same size.

Of course using the rcParams as in @tmdavison's answer is possible as well.

How can I make an "are you sure" prompt in a Windows batchfile?

Open terminal. Type the following

echo>sure.sh
chmod 700 sure.sh

Paste this inside sure.sh

#!\bin\bash

echo -n 'Are you sure? [Y/n] '
read yn

if [ "$yn" = "n" ]; then
    exit 1
fi

exit 0

Close sure.sh and type this in terminal.

alias sure='~/sure&&'

Now, if you type sure before typing the command it will give you an are you sure prompt before continuing the command.

Hope this is helpful!

How to justify navbar-nav in Bootstrap 3

<div class="navbar navbar-default navbar-fixed-top" role="navigation">
 <div class="container">
<div class="navbar-header">
  <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
    <span class="sr-only">Toggle navigation</span>
    <span class="icon-bar"></span>
    <span class="icon-bar"></span>
    <span class="icon-bar"></span>
  </button>
</div>
<div class="collapse navbar-collapse">
  <ul class="nav navbar-nav">
    <li><a href="#">Home</a></li>
    <li><a href="#about">About</a></li>
    <li><a href="#contact">Contact</a></li>  
  </ul>
</div>

and for the css

@media ( min-width: 768px ) { 
    .navbar > .container {
        text-align: center;
    }
    .navbar-header,.navbar-brand,.navbar .navbar-nav,.navbar .navbar-nav > li {
        float: none;
        display: inline-block;
    }
    .collapse.navbar-collapse {
        width: auto;
        clear: none;
    }
}

see it live http://www.bootply.com/103172

error: expected primary-expression before ')' token (C)

You're passing a type as an argument, not an object. You need to do characterSelection(screen, test); where test is of type SelectionneNonSelectionne.

Trim last 3 characters of a line WITHOUT using sed, or perl, etc

You can use awk just to print the first 'field' if there won't be any spaces (or if there will be, change the separator'.

I put the fields you had above into a file and did this

awk '{ print $1 }' < test.txt 
1234567890
1234567891

I don't know if that's any better.

Connect Java to a MySQL database

String url = "jdbc:mysql://127.0.0.1:3306/yourdatabase";
String user = "username";
String password = "password";

// Load the Connector/J driver
Class.forName("com.mysql.jdbc.Driver").newInstance();
// Establish connection to MySQL
Connection conn = DriverManager.getConnection(url, user, password);

Converting dictionary to JSON

json.dumps() is used to decode JSON data

  • json.loads take a string as input and returns a dictionary as output.
  • json.dumps take a dictionary as input and returns a string as output.
import json

# initialize different data
str_data = 'normal string'
int_data = 1
float_data = 1.50
list_data = [str_data, int_data, float_data]
nested_list = [int_data, float_data, list_data]
dictionary = {
    'int': int_data,
    'str': str_data,
    'float': float_data,
    'list': list_data,
    'nested list': nested_list
}

# convert them to JSON data and then print it
print('String :', json.dumps(str_data))
print('Integer :', json.dumps(int_data))
print('Float :', json.dumps(float_data))
print('List :', json.dumps(list_data))
print('Nested List :', json.dumps(nested_list, indent=4))
print('Dictionary :', json.dumps(dictionary, indent=4))  # the json data will be indented

output:

String : "normal string"
Integer : 1
Float : 1.5
List : ["normal string", 1, 1.5]
Nested List : [
    1,
    1.5,
    [
        "normal string",
        1,
        1.5
    ]
]
Dictionary : {
    "int": 1,
    "str": "normal string",
    "float": 1.5,
    "list": [
        "normal string",
        1,
        1.5
    ],
    "nested list": [
        1,
        1.5,
        [
            "normal string",
            1,
            1.5
        ]
    ]
}
  • Python Object to JSON Data Conversion
|                 Python                 |  JSON  |
|:--------------------------------------:|:------:|
|                  dict                  | object |
|               list, tuple              |  array |
|                   str                  | string |
| int, float, int- & float-derived Enums | number |
|                  True                  |  true  |
|                  False                 |  false |
|                  None                  |  null  |

How to get a product's image in Magento?

<img src='.$this->helper('catalog/image')->init($product, 'small_image')->resize(225, 225).' width=\'225\' height=\'225\'/>

Transparent ARGB hex value

If you have your hex value, and your just wondering what the value for the alpha would be, this snippet may help:

_x000D_
_x000D_
const alphaToHex = (alpha => {_x000D_
  if (alpha > 1 || alpha < 0 || isNaN(alpha)) {_x000D_
    throw new Error('The argument must be a number between 0 and 1');_x000D_
  }_x000D_
  return Math.ceil(255 * alpha).toString(16).toUpperCase();_x000D_
})_x000D_
_x000D_
console.log(alphaToHex(0.45));
_x000D_
_x000D_
_x000D_

Sorting dropdown alphabetically in AngularJS

var module = angular.module("example", []);

module.controller("orderByController", function ($scope) {
    $scope.orderByValue = function (value) {
        return value;
    };

    $scope.items = ["c", "b", "a"];
    $scope.objList = [
        {
            "name": "c"
        }, {
            "name": "b"
        }, {
            "name": "a"
        }];
        $scope.item = "b";
    });

http://jsfiddle.net/Nfv42/65/

Angular2: child component access parent class variable/function

What about a little trickery like NgModel does with NgForm? You have to register your parent as a provider, then load your parent in the constructor of the child.

That way, you don't have to put [sharedList] on all your children.

// Parent.ts
export var parentProvider = {
    provide: Parent,
    useExisting: forwardRef(function () { return Parent; })
};

@Component({
    moduleId: module.id,
    selector: 'parent',
    template: '<div><ng-content></ng-content></div>',
    providers: [parentProvider]
})
export class Parent {
    @Input()
    public sharedList = [];
}

// Child.ts
@Component({
    moduleId: module.id,
    selector: 'child',
    template: '<div>child</div>'
})
export class Child {
    constructor(private parent: Parent) {
        parent.sharedList.push('Me.');
    }
}

Then your HTML

<parent [sharedList]="myArray">
    <child></child>
    <child></child>
</parent>

You can find more information on the subject in the Angular documentation: https://angular.io/guide/dependency-injection-in-action#find-a-parent-component-by-injection

What is the fastest/most efficient way to find the highest set bit (msb) in an integer in C?

Since 2^N is an integer with only the Nth bit set (1 << N), finding the position (N) of the highest set bit is the integer log base 2 of that integer.

http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogObvious

unsigned int v;
unsigned r = 0;

while (v >>= 1) {
    r++;
}

This "obvious" algorithm may not be transparent to everyone, but when you realize that the code shifts right by one bit repeatedly until the leftmost bit has been shifted off (note that C treats any non-zero value as true) and returns the number of shifts, it makes perfect sense. It also means that it works even when more than one bit is set — the result is always for the most significant bit.

If you scroll down on that page, there are faster, more complex variations. However, if you know you're dealing with numbers with a lot of leading zeroes, the naive approach may provide acceptable speed, since bit shifting is rather fast in C, and the simple algorithm doesn't require indexing an array.

NOTE: When using 64-bit values, be extremely cautious about using extra-clever algorithms; many of them only work correctly for 32-bit values.

Node.js fs.readdir recursive directory search

Another simple and helpful one

function walkDir(root) {
    const stat = fs.statSync(root);

    if (stat.isDirectory()) {
        const dirs = fs.readdirSync(root).filter(item => !item.startsWith('.'));
        let results = dirs.map(sub => walkDir(`${root}/${sub}`));
        return [].concat(...results);
    } else {
        return root;
    }
}

Basic text editor in command prompt?

notepad filename.extension will open notepad editor

Create intermediate folders if one doesn't exist

A nice Java 7+ answer from Benoit Blanchon can be found here:

With Java 7, you can use Files.createDirectories().

For instance:

Files.createDirectories(Paths.get("/path/to/directory"));

How do I write out a text file in C# with a code page other than UTF-8?

Simple!

System.IO.File.WriteAllText(path, text, Encoding.GetEncoding(28591));

How can I get a web site's favicon?

You can do it without programming. Just open the web site, right-click and select "view source" to open the HTML code of that site. Then in the text editor search for "favicon" - it will direct you to something looking like

<link rel="icon" href='/SOMERELATIVEPATH/favicon.ico' type="image/x-icon" />

take the string in href and append it to the web site's base URL (let's assume it is "http://WEBSITE/"), so it looks like

http://WEBSITE/SOMERELATIVEPATH/favicon.ico

which is the absolute path to the favicon. If you didn't find it this way, it can be as well in the root in which case the URL is http://WEBSITE/favicon.ico.

Take the URL you determined and insert it into the following code:

<html>
  <head>
   <title>Capture Favicon</title>   
  </head>
  <body>
    <a href='http://WEBSITE/SOMERELATIVEPATH/favicon.ico' alt="Favicon"/>Favicon</a> 
  </body>
</html>

Save this HTML code locally (e.g. on your desktop) as GetFavicon.html and then double-click on it to open it. It will display only a link named Favicon. Right-click on this link and select "Save target as..." to save the Favicon on your local PC - and you're done!

How to change node.js's console font color?

paint-console

Simple colorable log. Support inspect objects and single line update This package just repaint console.

install

npm install paint-console

usage

require('paint-console');

console.info('console.info();');
console.warn('console.warn();');
console.error('console.error();');
console.log('console.log();');

demo

How do I correct this Illegal String Offset?

if(isset($rule["type"]) && ($rule["type"] == "radio") || ($rule["type"] == "checkbox") )
{
    if(!isset($data[$field]))
        $data[$field]="";
}

Throughput and bandwidth difference?

  • Bandwidth - theoretical maximum units of work per unit of time
  • Throughput - actual units of work per unit of time

As opposed to the time per unit of work (speed/latency).

This question in network engineering stack exchange contains good responses: https://networkengineering.stackexchange.com/questions/10504/what-is-the-difference-between-data-rate-and-latency

Unlink of file Failed. Should I try again?

I had the same issue while doing a git pull and as stated above, it was because of a program that was holding those files and was not allowing a git pull. Closing the program helped. Usually, the IDE (like Eclipse) from where the files are being checked-in will be holding it in the background. Closing the same and re-running git pull solved the problem for me.

Check if a div exists with jquery

The first is the most concise, I would go with that. The first two are the same, but the first is just that little bit shorter, so you'll save on bytes. The third is plain wrong, because that condition will always evaluate true because the object will never be null or falsy for that matter.

The backend version is not supported to design database diagrams or tables

I ran into this problem when SQL Server 2014 standard was installed on a server where SQL Server Express was also installed. I had opened SSMS from a desktop shortcut, not realizing right away that it was SSMS for SQL Server Express, not for 2014. SSMS for Express returned the error, but SQL Server 2014 did not.

How to add a button dynamically using jquery

Try this:

<script type="text/javascript">

function test()
{
    if($('input#field').length==0)
    {
       $('<input type="button" id="field"/>').appendTo('body');
     }
}
</script>

Oracle 'Partition By' and 'Row_Number' keyword

I know this is an old thread but PARTITION is the equiv of GROUP BY not ORDER BY. ORDER BY in this function is . . . ORDER BY. It's just a way to create uniqueness out of redundancy by adding a sequence number. Or you may eliminate the other redundant records by the WHERE clause when referencing the aliased column for the function. However, DISTINCT in the SELECT statement would probably accomplish the same thing in that regard.

Tomcat: How to find out running tomcat version

run the following

/usr/local/tomcat/bin/catalina.sh version

its response will be something like:

Using CATALINA_BASE:   /usr/local/tomcat
Using CATALINA_HOME:   /usr/local/tomcat
Using CATALINA_TMPDIR: /var/tmp/
Using JRE_HOME:        /usr
Using CLASSPATH:       /usr/local/tomcat/bin/bootstrap.jar:/usr/local/tomcat/bin/tomcat-juli.jar
Using CATALINA_PID:    /var/catalina.pid
Server version: Apache Tomcat/7.0.30
Server built:   Sep 27 2012 05:13:37
Server number:  7.0.30.0
OS Name:        Linux
OS Version:     2.6.32-504.3.3.el6.x86_64
Architecture:   amd64
JVM Version:    1.7.0_60-b19
JVM Vendor:     Oracle Corporation

How do you change the character encoding of a postgres database?

To change the encoding of your database:

  1. Dump your database
  2. Drop your database,
  3. Create new database with the different encoding
  4. Reload your data.

Make sure the client encoding is set correctly during all this.

Source: http://archives.postgresql.org/pgsql-novice/2006-03/msg00210.php

What is The Rule of Three?

Introduction

C++ treats variables of user-defined types with value semantics. This means that objects are implicitly copied in various contexts, and we should understand what "copying an object" actually means.

Let us consider a simple example:

class person
{
    std::string name;
    int age;

public:

    person(const std::string& name, int age) : name(name), age(age)
    {
    }
};

int main()
{
    person a("Bjarne Stroustrup", 60);
    person b(a);   // What happens here?
    b = a;         // And here?
}

(If you are puzzled by the name(name), age(age) part, this is called a member initializer list.)

Special member functions

What does it mean to copy a person object? The main function shows two distinct copying scenarios. The initialization person b(a); is performed by the copy constructor. Its job is to construct a fresh object based on the state of an existing object. The assignment b = a is performed by the copy assignment operator. Its job is generally a little more complicated, because the target object is already in some valid state that needs to be dealt with.

Since we declared neither the copy constructor nor the assignment operator (nor the destructor) ourselves, these are implicitly defined for us. Quote from the standard:

The [...] copy constructor and copy assignment operator, [...] and destructor are special member functions. [ Note: The implementation will implicitly declare these member functions for some class types when the program does not explicitly declare them. The implementation will implicitly define them if they are used. [...] end note ] [n3126.pdf section 12 §1]

By default, copying an object means copying its members:

The implicitly-defined copy constructor for a non-union class X performs a memberwise copy of its subobjects. [n3126.pdf section 12.8 §16]

The implicitly-defined copy assignment operator for a non-union class X performs memberwise copy assignment of its subobjects. [n3126.pdf section 12.8 §30]

Implicit definitions

The implicitly-defined special member functions for person look like this:

// 1. copy constructor
person(const person& that) : name(that.name), age(that.age)
{
}

// 2. copy assignment operator
person& operator=(const person& that)
{
    name = that.name;
    age = that.age;
    return *this;
}

// 3. destructor
~person()
{
}

Memberwise copying is exactly what we want in this case: name and age are copied, so we get a self-contained, independent person object. The implicitly-defined destructor is always empty. This is also fine in this case since we did not acquire any resources in the constructor. The members' destructors are implicitly called after the person destructor is finished:

After executing the body of the destructor and destroying any automatic objects allocated within the body, a destructor for class X calls the destructors for X's direct [...] members [n3126.pdf 12.4 §6]

Managing resources

So when should we declare those special member functions explicitly? When our class manages a resource, that is, when an object of the class is responsible for that resource. That usually means the resource is acquired in the constructor (or passed into the constructor) and released in the destructor.

Let us go back in time to pre-standard C++. There was no such thing as std::string, and programmers were in love with pointers. The person class might have looked like this:

class person
{
    char* name;
    int age;

public:

    // the constructor acquires a resource:
    // in this case, dynamic memory obtained via new[]
    person(const char* the_name, int the_age)
    {
        name = new char[strlen(the_name) + 1];
        strcpy(name, the_name);
        age = the_age;
    }

    // the destructor must release this resource via delete[]
    ~person()
    {
        delete[] name;
    }
};

Even today, people still write classes in this style and get into trouble: "I pushed a person into a vector and now I get crazy memory errors!" Remember that by default, copying an object means copying its members, but copying the name member merely copies a pointer, not the character array it points to! This has several unpleasant effects:

  1. Changes via a can be observed via b.
  2. Once b is destroyed, a.name is a dangling pointer.
  3. If a is destroyed, deleting the dangling pointer yields undefined behavior.
  4. Since the assignment does not take into account what name pointed to before the assignment, sooner or later you will get memory leaks all over the place.

Explicit definitions

Since memberwise copying does not have the desired effect, we must define the copy constructor and the copy assignment operator explicitly to make deep copies of the character array:

// 1. copy constructor
person(const person& that)
{
    name = new char[strlen(that.name) + 1];
    strcpy(name, that.name);
    age = that.age;
}

// 2. copy assignment operator
person& operator=(const person& that)
{
    if (this != &that)
    {
        delete[] name;
        // This is a dangerous point in the flow of execution!
        // We have temporarily invalidated the class invariants,
        // and the next statement might throw an exception,
        // leaving the object in an invalid state :(
        name = new char[strlen(that.name) + 1];
        strcpy(name, that.name);
        age = that.age;
    }
    return *this;
}

Note the difference between initialization and assignment: we must tear down the old state before assigning to name to prevent memory leaks. Also, we have to protect against self-assignment of the form x = x. Without that check, delete[] name would delete the array containing the source string, because when you write x = x, both this->name and that.name contain the same pointer.

Exception safety

Unfortunately, this solution will fail if new char[...] throws an exception due to memory exhaustion. One possible solution is to introduce a local variable and reorder the statements:

// 2. copy assignment operator
person& operator=(const person& that)
{
    char* local_name = new char[strlen(that.name) + 1];
    // If the above statement throws,
    // the object is still in the same state as before.
    // None of the following statements will throw an exception :)
    strcpy(local_name, that.name);
    delete[] name;
    name = local_name;
    age = that.age;
    return *this;
}

This also takes care of self-assignment without an explicit check. An even more robust solution to this problem is the copy-and-swap idiom, but I will not go into the details of exception safety here. I only mentioned exceptions to make the following point: Writing classes that manage resources is hard.

Noncopyable resources

Some resources cannot or should not be copied, such as file handles or mutexes. In that case, simply declare the copy constructor and copy assignment operator as private without giving a definition:

private:

    person(const person& that);
    person& operator=(const person& that);

Alternatively, you can inherit from boost::noncopyable or declare them as deleted (in C++11 and above):

person(const person& that) = delete;
person& operator=(const person& that) = delete;

The rule of three

Sometimes you need to implement a class that manages a resource. (Never manage multiple resources in a single class, this will only lead to pain.) In that case, remember the rule of three:

If you need to explicitly declare either the destructor, copy constructor or copy assignment operator yourself, you probably need to explicitly declare all three of them.

(Unfortunately, this "rule" is not enforced by the C++ standard or any compiler I am aware of.)

The rule of five

From C++11 on, an object has 2 extra special member functions: the move constructor and move assignment. The rule of five states to implement these functions as well.

An example with the signatures:

class person
{
    std::string name;
    int age;

public:
    person(const std::string& name, int age);        // Ctor
    person(const person &) = default;                // 1/5: Copy Ctor
    person(person &&) noexcept = default;            // 4/5: Move Ctor
    person& operator=(const person &) = default;     // 2/5: Copy Assignment
    person& operator=(person &&) noexcept = default; // 5/5: Move Assignment
    ~person() noexcept = default;                    // 3/5: Dtor
};

The rule of zero

The rule of 3/5 is also referred to as the rule of 0/3/5. The zero part of the rule states that you are allowed to not write any of the special member functions when creating your class.

Advice

Most of the time, you do not need to manage a resource yourself, because an existing class such as std::string already does it for you. Just compare the simple code using a std::string member to the convoluted and error-prone alternative using a char* and you should be convinced. As long as you stay away from raw pointer members, the rule of three is unlikely to concern your own code.

What is the proper way to URL encode Unicode characters?

I would always encode in UTF-8. From the Wikipedia page on percent encoding:

The generic URI syntax mandates that new URI schemes that provide for the representation of character data in a URI must, in effect, represent characters from the unreserved set without translation, and should convert all other characters to bytes according to UTF-8, and then percent-encode those values. This requirement was introduced in January 2005 with the publication of RFC 3986. URI schemes introduced before this date are not affected.

It seems like because there were other accepted ways of doing URL encoding in the past, browsers attempt several methods of decoding a URI, but if you're the one doing the encoding you should use UTF-8.

How to deal with "data of class uneval" error from ggplot2?

when you add a new data set to a geom you need to use the data= argument. Or put the arguments in the proper order mapping=..., data=.... Take a look at the arguments for ?geom_line.

Thus:

p + geom_line(data=df.last, aes(HrEnd, MWh, group=factor(Date)), color="red") 

Or:

p + geom_line(aes(HrEnd, MWh, group=factor(Date)), df.last, color="red") 

Reading a single char in Java

Using nextline and System.in.read as often proposed requires the user to hit enter after typing a character. However, people searching for an answer to this question, may also be interested in directly respond to a key press in a console!

I found a solution to do so using jline3, wherein we first change the terminal into rawmode to directly respond to keys, and then wait for the next entered character:

var terminal = TerminalBuilder.terminal()
terminal.enterRawMode()
var reader = terminal.reader()

var c = reader.read()
<dependency>
    <groupId>org.jline</groupId>
    <artifactId>jline</artifactId>
    <version>3.12.3</version>
</dependency>

SQL Server datetime LIKE select?

There is a very flaky coverage of the LIKE operator for dates in SQL Server. It only works using American date format. As an example you could try:

... WHERE register_date LIKE 'oct 10 2009%'

I've tested this in SQL Server 2005 and it works, but you'll really need to try different combinations. Odd things I have noticed are:

  • You only seem to get all or nothing for different sub fields within the date, for instance, if you search for 'apr 2%' you only get anything in the 20th's - it omits 2nd's.

  • Using a single underscore '_' to represent a single (wildcard) character does not wholly work, for instance, WHERE mydate LIKE 'oct _ 2010%' will not return all dates before the 10th - it returns nothing at all, in fact!

  • The format is rigid American: 'mmm dd yyyy hh:mm'

I have found it difficult to nail down a process for LIKEing seconds, so if anyone wants to take this a bit further, be my guest!

Hope this helps.

Regex lookahead, lookbehind and atomic groups

Examples

Given the string foobarbarfoo:

bar(?=bar)     finds the 1st bar ("bar" which has "bar" after it)
bar(?!bar)     finds the 2nd bar ("bar" which does not have "bar" after it)
(?<=foo)bar    finds the 1st bar ("bar" which has "foo" before it)
(?<!foo)bar    finds the 2nd bar ("bar" which does not have "foo" before it)

You can also combine them:

(?<=foo)bar(?=bar)    finds the 1st bar ("bar" with "foo" before it and "bar" after it)

Definitions

Look ahead positive (?=)

Find expression A where expression B follows:

A(?=B)

Look ahead negative (?!)

Find expression A where expression B does not follow:

A(?!B)

Look behind positive (?<=)

Find expression A where expression B precedes:

(?<=B)A

Look behind negative (?<!)

Find expression A where expression B does not precede:

(?<!B)A

Atomic groups (?>)

An atomic group exits a group and throws away alternative patterns after the first matched pattern inside the group (backtracking is disabled).

  • (?>foo|foot)s applied to foots will match its 1st alternative foo, then fail as s does not immediately follow, and stop as backtracking is disabled

A non-atomic group will allow backtracking; if subsequent matching ahead fails, it will backtrack and use alternative patterns until a match for the entire expression is found or all possibilities are exhausted.

  • (foo|foot)s applied to foots will:

    1. match its 1st alternative foo, then fail as s does not immediately follow in foots, and backtrack to its 2nd alternative;
    2. match its 2nd alternative foot, then succeed as s immediately follows in foots, and stop.

Some resources

Online testers

How to check if anonymous object has a method?

What do you mean by an "anonymous object?" myObj is not anonymous since you've assigned an object literal to a variable. You can just test this:

if (typeof myObj.prop2 === 'function')
{
    // do whatever
}