Programs & Examples On #Reverse engineering

Reverse engineering is the process of discovering the technological principles of a human made device, object or system through analysis of its structure, function and operation.

JNZ & CMP Assembly Instructions

JNZ     Jump if Not Zero    ZF=0

Indeed, this is confusing right.

To make it easier to understand, replace Not Zero with Not Set. (Please take note this is for your own understanding)

Hence,

JNZ     Jump if Not Set     ZF=0

Not Set means flag Z = 0. So Jump (Jump if Not Set)

Set means flag Z = 1. So, do NOT Jump

Sniffing/logging your own Android Bluetooth traffic

Android 4.4 (Kit Kat) does have a new sniffing capability for Bluetooth. You should give it a try.

If you don’t own a sniffing device however, you aren’t necessarily out of luck. In many cases we can obtain positive results with a new feature introduced in Android 4.4: the ability to capture all Bluetooth HCI packets and save them to a file.

When the Analyst has finished populating the capture file by running the application being tested, he can pull the file generated by Android into the external storage of the device and analyze it (with Wireshark, for example).

Once this setting is activated, Android will save the packet capture to /sdcard/btsnoop_hci.log to be pulled by the analyst and inspected.

Type the following in case /sdcard/ is not the right path on your particular device:

adb shell echo \$EXTERNAL_STORAGE

We can then open a shell and pull the file: $adb pull /sdcard/btsnoop_hci.log and inspect it with Wireshark, just like a PCAP collected by sniffing WiFi traffic for example, so it is very simple and well supported:

screenshot of wireshark capture using Android HCI Snoop

[source]

You can enable this by going to Settings->Developer Options, then checking the box next to "Bluetooth HCI Snoop Log."

List of all index & index columns in SQL Server DB

I have used the following query when I had this requirement...

SELECT 
    TableName = t.name,
    ColumnId = col.column_id, 
    ColumnName = col.name,
    DataType = ty.name,
    MaxSize = ty.max_length,
    IsNullable = CASE WHEN (col.is_nullable = 1) THEN 'Y' END,
    IsIdentity = CASE WHEN (col.is_identity = 1) THEN 'Y' END,
    IsPrimaryKey = CASE WHEN (ic.column_id = col.column_id) THEN 'Y' END,
    IsForeignKey = CASE WHEN (fkc.parent_column_id = col.column_id) THEN 'Y' END,
    IsDefault = CASE WHEN (dc.parent_column_id = col.column_id) THEN 'Y' END
FROM 
    sys.tables t
INNER JOIN 
     sys.columns col ON t.object_id = col.object_id 
LEFT JOIN
    sys.indexes ind ON t.object_id = ind.object_id 
LEFT JOIN 
     sys.index_columns ic ON ic.index_id=ind.index_id AND ic.object_id = col.object_id and ic.column_id = col.column_id
LEFT JOIN sys.foreign_key_columns fkc
                ON fkc.parent_object_id = col.object_id AND fkc.parent_column_id=col.column_id
LEFT JOIN sys.default_constraints dc
                ON dc.parent_object_id = col.object_id AND dc.parent_column_id=col.column_id
LEFT JOIN
     sys.types ty on ty.user_type_id = col.user_type_id

WHERE
    --t.name='<TABLENAME>'
    t.schema_id = 10    --SCHEMA ID
    AND ind.is_primary_key=1    
ORDER BY
    t.name, ColumnId

Is there a C++ decompiler?

Depending on how large and how well-written the original code was, it might be worth starting again in your favourite language (which might still be C++) and learning from any mistakes made in the last version. Didn't someone once say about writing one to throw away?

n.b. Clearly if this is a huge product, then it may not be worth the time.

What is the iBeacon Bluetooth Profile

For an iBeacon with ProximityUUID E2C56DB5-DFFB-48D2-B060-D0F5A71096E0, major 0, minor 0, and calibrated Tx Power of -59 RSSI, the transmitted BLE advertisement packet looks like this:

d6 be 89 8e 40 24 05 a2 17 6e 3d 71 02 01 1a 1a ff 4c 00 02 15 e2 c5 6d b5 df fb 48 d2 b0 60 d0 f5 a7 10 96 e0 00 00 00 00 c5 52 ab 8d 38 a5

This packet can be broken down as follows:

d6 be 89 8e # Access address for advertising data (this is always the same fixed value)
40 # Advertising Channel PDU Header byte 0.  Contains: (type = 0), (tx add = 1), (rx add = 0)
24 # Advertising Channel PDU Header byte 1.  Contains:  (length = total bytes of the advertising payload + 6 bytes for the BLE mac address.)
05 a2 17 6e 3d 71 # Bluetooth Mac address (note this is a spoofed address)
02 01 1a 1a ff 4c 00 02 15 e2 c5 6d b5 df fb 48 d2 b0 60 d0 f5 a7 10 96 e0 00 00 00 00 c5 # Bluetooth advertisement
52 ab 8d 38 a5 # checksum

The key part of that packet is the Bluetooth Advertisement, which can be broken down like this:

02 # Number of bytes that follow in first AD structure
01 # Flags AD type
1A # Flags value 0x1A = 000011010  
   bit 0 (OFF) LE Limited Discoverable Mode
   bit 1 (ON) LE General Discoverable Mode
   bit 2 (OFF) BR/EDR Not Supported
   bit 3 (ON) Simultaneous LE and BR/EDR to Same Device Capable (controller)
   bit 4 (ON) Simultaneous LE and BR/EDR to Same Device Capable (Host)
1A # Number of bytes that follow in second (and last) AD structure
FF # Manufacturer specific data AD type
4C 00 # Company identifier code (0x004C == Apple)
02 # Byte 0 of iBeacon advertisement indicator
15 # Byte 1 of iBeacon advertisement indicator
e2 c5 6d b5 df fb 48 d2 b0 60 d0 f5 a7 10 96 e0 # iBeacon proximity uuid
00 00 # major 
00 00 # minor 
c5 # The 2's complement of the calibrated Tx Power

Any Bluetooth LE device that can be configured to send a specific advertisement can generate the above packet. I have configured a Linux computer using Bluez to send this advertisement, and iOS7 devices running Apple's AirLocate test code pick it up as an iBeacon with the fields specified above. See: Use BlueZ Stack As A Peripheral (Advertiser)

This blog has full details about the reverse engineering process.

How to generate UML diagrams (especially sequence diagrams) from Java code?

There is a Free tool named binarydoc which can generate UML Sequence Diagram, or Control Flow Graph (CFG) from the bytecode (instead of source code) of a Java method.

Here is an sample diagram binarydoc generated for the java method java.net.AbstractPlainSocketImpl.getInputStream:

  • Control Flow Graph of method java.net.AbstractPlainSocketImpl.getInputStream:

Control Flow Graph

  • UML Sequence Diagram of method java.net.AbstractPlainSocketImpl.getInputStream:

UML Sequence Diagram

How to avoid reverse engineering of an APK file?

 1. How can I completely avoid reverse engineering of an Android APK? Is this possible?

This isn't possible

 2. How can I protect all the app's resources, assets and source code so that hackers can't hack the APK file in any way?

When somebody change a .apk extension to .zip, then after unzipping, someone can easily get all resources (except Manifest.xml), but with APKtool one can get the real content of the manifest file too. Again, a no.

 3. Is there a way to make hacking more tough or even impossible? What more can I do to protect the source code in my APK file?

Again, no, but you can prevent upto some level, that is,

  • Download a resource from the Web and do some encryption process
  • Use a pre-compiled native library (C, C++, JNI, NDK)
  • Always perform some hashing (MD5/SHA keys or any other logic)

Even with Smali, people can play with your code. All in all, it's not POSSIBLE.

Best practice for storing and protecting private API keys in applications

The App-Secret key should be kept private - but when releasing the app they can be reversed by some guys.

for those guys it will not hide, lock the either the ProGuard the code. It is a refactor and some payed obfuscators are inserting a few bitwise operators to get back the jk433g34hg3 String. You can make 5 -15 min longer the hacking if you work 3 days :)

Best way is to keep it as it is, imho.

Even if you store at server side( your PC ) the key can be hacked and printed out. Maybe this takes the longest? Anyhow it is a matter of few minutes or a few hours in best case.

A normal user will not decompile your code.

decompiling DEX into Java sourcecode

Android Reverse Engineering is possible . Follow these steps to get .java file from apk file.

Step1 . Using dex2jar

  • Generate .jar file from .apk file
  • command : dex2jar sampleApp.apk

Step2 . Decompiling .jar using JD-GUI

  • it decompiles the .class files i.e., we'll get obfuscated .java back from the apk.

Protect .NET code from reverse engineering?

If Microsoft could come up with a solution, we will not have pirated Windows versions, so nothing is very secure. Here are some similar questions from Stack Overflow and you can implement your own way of protecting them. If you are releasing different versions then you can adopt different techniques for different version so by the time first one is cracked the second one can take over.

Generate UML Class Diagram from Java Project

How about the Omondo Plugin for Eclipse. I have used it and I find it to be quite useful. Although if you are generating diagrams for large sources, you might have to start Eclipse with more memory.

Generate ER Diagram from existing MySQL database, created for CakePHP

CakePHP was intended to be used as Ruby on Rails framework clone, done in PHP, so any reverse-engineering of underlying database is pointless. EER diagrams should be reverse-engineered from Model layer.

Such tools do exist for Ruby Here you can see Redmine database EER diagrams reverse-engineered from Models. Not from database. http://redminecookbook.com/Redmine-erd-diagrams.html

With following tools: http://rails-erd.rubyforge.org/ http://railroady.prestonlee.com/

What's a good, free serial port monitor for reverse-engineering?

I hear a lot of good things about com0com, which is a software port emulator. You can "connect" a physical serial port through it, so that your software uses the (monitored) virtual port, and forwards all traffic to/from a physical port. I haven't used it myself, but I've seen it recommended here on SO a lot.

How do you extract classes' source code from a dll file?

You can use Reflector and also use Add-In FileGenerator to extract source code into a project.

Is there a program to decompile Delphi?

Here's a list : http://delphi.about.com/od/devutilities/a/decompiling_3.htm (and this page mentions some more : http://www.program-transformation.org/Transform/DelphiDecompilers )

I've used DeDe on occasion, but it's not really all that powerfull, and it's not up-to-date with current Delphi versions (latest version it supports is Delphi 7 I believe)

The VMware Authorization Service is not running

Try executing vmware as administrator

Read binary file as string in Ruby

how about some open/close safety.

string = File.open('file.txt', 'rb') { |file| file.read }

Array String Declaration

You can write like below. Check out the syntax guidelines in this thread

AClass[] array;
...
array = new AClass[]{object1, object2};

If you find arrays annoying better use ArrayList.

Append text to textarea with javascript

Give this a try:

<!DOCTYPE html>
<html>
<head>
    <title>List Test</title>
    <style>
        li:hover {
            cursor: hand; cursor: pointer;
        }
    </style>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
    <script>
        $(document).ready(function(){
            $("li").click(function(){
                $('#alltext').append($(this).text());
            });
        });
    </script>
</head>
<body>

    <h2>List items</h2>
    <ol>
        <li>Hello</li>
        <li>World</li>
        <li>Earthlings</li>
    </ol>
    <form>
        <textarea id="alltext"></textarea>
    </form>

</body>
</html>

Convert JSON array to Python list

Tested on Ideone.


import json
array = '{"fruits": ["apple", "banana", "orange"]}'
data  = json.loads(array)
fruits_list = data['fruits']
print fruits_list

Javascript change date into format of (dd/mm/yyyy)

This will ensure you get a two-digit day and month.

function formattedDate(d = new Date) {
  let month = String(d.getMonth() + 1);
  let day = String(d.getDate());
  const year = String(d.getFullYear());

  if (month.length < 2) month = '0' + month;
  if (day.length < 2) day = '0' + day;

  return `${day}/${month}/${year}`;
}

Or terser:

function formattedDate(d = new Date) {
  return [d.getDate(), d.getMonth()+1, d.getFullYear()]
      .map(n => n < 10 ? `0${n}` : `${n}`).join('/');
}

Why does make think the target is up to date?

Maybe you have a file/directory named test in the directory. If this directory exists, and has no dependencies that are more recent, then this target is not rebuild.

To force rebuild on these kind of not-file-related targets, you should make them phony as follows:

.PHONY: all test clean

Note that you can declare all of your phony targets there.

A phony target is one that is not really the name of a file; rather it is just a name for a recipe to be executed when you make an explicit request.

SQL Server 2005 Setting a variable to the result of a select query

You could also just put the first SELECT in a subquery. Since most optimizers will fold it into a constant anyway, there should not be a performance hit on this.

Incidentally, since you are using a predicate like this:

CONVERT(...) = CONVERT(...)

that predicate expression cannot be optimized properly or use indexes on the columns reference by the CONVERT() function.

Here is one way to make the original query somewhat better:

DECLARE @ooDate datetime
SELECT @ooDate = OO.Date FROM OLAP.OutageHours AS OO where OO.OutageID = 1

SELECT 
  COUNT(FF.HALID)
FROM
  Outages.FaultsInOutages AS OFIO 
  INNER JOIN Faults.Faults as FF ON 
    FF.HALID = OFIO.HALID 
WHERE
  FF.FaultDate >= @ooDate AND
  FF.FaultDate < DATEADD(day, 1, @ooDate) AND
  OFIO.OutageID = 1

This version could leverage in index that involved FaultDate, and achieves the same goal.

Here it is, rewritten to use a subquery to avoid the variable declaration and subsequent SELECT.

SELECT 
  COUNT(FF.HALID)
FROM
  Outages.FaultsInOutages AS OFIO 
  INNER JOIN Faults.Faults as FF ON 
    FF.HALID = OFIO.HALID 
WHERE
  CONVERT(varchar(10), FF.FaultDate, 126) = (SELECT CONVERT(varchar(10), OO.Date, 126) FROM OLAP.OutageHours AS OO where OO.OutageID = 1) AND
  OFIO.OutageID = 1

Note that this approach has the same index usage issue as the original, because of the use of CONVERT() on FF.FaultDate. This could be remedied by adding the subquery twice, but you would be better served with the variable approach in this case. This last version is only for demonstration.

Regards.

How to check if internet connection is present in Java?

The following piece of code allows us to get the status of the network on our Android device

public class MainActivity extends AppCompatActivity {
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            TextView mtv=findViewById(R.id.textv);
            ConnectivityManager connectivityManager=
                  (ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE);
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                if(((Network)connectivityManager.getActiveNetwork())!=null)
                    mtv.setText("true");
                else
                    mtv.setText("fasle");
            }
        }
    }

SQL RANK() versus ROW_NUMBER()

Also, pay attention to ORDER BY in PARTITION (Standard AdventureWorks db is used for example) when using RANK.

SELECT as1.SalesOrderID, as1.SalesOrderDetailID, RANK() OVER (PARTITION BY as1.SalesOrderID ORDER BY as1.SalesOrderID ) ranknoequal , RANK() OVER (PARTITION BY as1.SalesOrderID ORDER BY as1.SalesOrderDetailId ) ranknodiff FROM Sales.SalesOrderDetail as1 WHERE SalesOrderId = 43659 ORDER BY SalesOrderDetailId;

Gives result:

SalesOrderID SalesOrderDetailID rank_same_as_partition rank_salesorderdetailid
43659 1 1 1
43659 2 1 2
43659 3 1 3
43659 4 1 4
43659 5 1 5
43659 6 1 6
43659 7 1 7
43659 8 1 8
43659 9 1 9
43659 10 1 10
43659 11 1 11
43659 12 1 12

But if change order by to (use OrderQty :

SELECT as1.SalesOrderID, as1.OrderQty, RANK() OVER (PARTITION BY as1.SalesOrderID ORDER BY as1.SalesOrderID ) ranknoequal , RANK() OVER (PARTITION BY as1.SalesOrderID ORDER BY as1.OrderQty ) rank_orderqty FROM Sales.SalesOrderDetail as1 WHERE SalesOrderId = 43659 ORDER BY OrderQty;

Gives:

SalesOrderID OrderQty rank_salesorderid rank_orderqty
43659 1 1 1
43659 1 1 1
43659 1 1 1
43659 1 1 1
43659 1 1 1
43659 1 1 1
43659 2 1 7
43659 2 1 7
43659 3 1 9
43659 3 1 9
43659 4 1 11
43659 6 1 12

Notice how the Rank changes when we use OrderQty (rightmost column second table) in ORDER BY and how it changes when we use SalesOrderDetailID (rightmost column first table) in ORDER BY.

Converting milliseconds to a date (jQuery/JavaScript)

One line code.

var date = new Date(new Date().getTime());

or

var date = new Date(1584120305684);

Find all controls in WPF Window by type

My version for C++/CLI

template < class T, class U >
bool Isinst(U u) 
{
    return dynamic_cast< T >(u) != nullptr;
}

template <typename T>
    T FindVisualChildByType(Windows::UI::Xaml::DependencyObject^ element, Platform::String^ name)
    {
        if (Isinst<T>(element) && dynamic_cast<Windows::UI::Xaml::FrameworkElement^>(element)->Name == name)
        {
            return dynamic_cast<T>(element);
        }
        int childcount = Windows::UI::Xaml::Media::VisualTreeHelper::GetChildrenCount(element);
        for (int i = 0; i < childcount; ++i)
        {
            auto childElement = FindVisualChildByType<T>(Windows::UI::Xaml::Media::VisualTreeHelper::GetChild(element, i), name);
            if (childElement != nullptr)
            {
                return childElement;
            }
        }
        return nullptr;
    };

Android: Color To Int conversion

R.color.black or some color are obviously integers. It needs a RGB value. You can give your own like #FF123454 which represents various primary colors

how to return index of a sorted list?

Straight out of the documentation for collections.OrderedDict:

>>> # dictionary sorted by value
>>> OrderedDict(sorted(d.items(), key=lambda t: t[1]))
OrderedDict([('pear', 1), ('orange', 2), ('banana', 3), ('apple', 4)])

Adapted to the example in the original post:

>>> l=[2,3,1,4,5]
>>> OrderedDict(sorted(enumerate(l), key=lambda x: x[1])).keys()
[2, 0, 1, 3, 4]

See http://docs.python.org/library/collections.html#collections.OrderedDict for details.

Arrow operator (->) usage in C

Yes, that's it.

It's just the dot version when you want to access elements of a struct/class that is a pointer instead of a reference.

struct foo
{
  int x;
  float y;
};

struct foo var;
struct foo* pvar;
pvar = malloc(sizeof(pvar));

var.x = 5;
(&var)->y = 14.3;
pvar->y = 22.4;
(*pvar).x = 6;

That's it!

How to use background thread in swift?

Swift 3 version

Swift 3 utilizes new DispatchQueue class to manage queues and threads. To run something on the background thread you would use:

let backgroundQueue = DispatchQueue(label: "com.app.queue", qos: .background)
backgroundQueue.async {
    print("Run on background thread")
}

Or if you want something in two lines of code:

DispatchQueue.global(qos: .background).async {
    print("Run on background thread")

    DispatchQueue.main.async {
        print("We finished that.")
        // only back on the main thread, may you access UI:
        label.text = "Done."
    }
}

You can also get some in-depth info about GDC in Swift 3 in this tutorial.

Calling Oracle stored procedure from C#?

This Code works well for me calling oracle stored procedure

Add references by right clicking on your project name in solution explorer >Add Reference >.Net then Add namespaces.

using System.Data.OracleClient;
using System.Data;

then paste this code in event Handler

        string str = "User ID=username;Password=password;Data Source=Test";
        OracleConnection conn = new OracleConnection(str);
        OracleCommand cmd = new OracleCommand("stored_procedure_name", conn);
        cmd.CommandType = CommandType.StoredProcedure;
        --Ad parameter list--
        cmd.Parameters.Add("parameter_name", "varchar2").Value = value;
        ....
        conn.Open();
        cmd.ExecuteNonQuery();

And its Done...Happy Coding with C#

MySQL: Insert record if not exists in table

You can easily use the following way :

INSERT INTO ... ON DUPLICATE KEY UPDATE ...

By this way you can insert any new raw and if you have duplicate data, replace specific column ( best columns is timestamps ).
For example :

CREATE TABLE IF NOT EXISTS Devices (
  id         INT(6)       NOT NULL AUTO_INCREMENT,
  unique_id  VARCHAR(100) NOT NULL PRIMARY KEY,
  created_at VARCHAR(100) NOT NULL,
  UNIQUE KEY unique_id (unique_id),
  UNIQUE KEY id (id)
)
  CHARACTER SET utf8
  COLLATE utf8_unicode_ci;

INSERT INTO Devices(unique_id, time) 
VALUES('$device_id', '$current_time') 
ON DUPLICATE KEY UPDATE time = '$current_time';

bash echo number of lines of file given in a bash variable without the file name

wc can't get the filename if you don't give it one.

wc -l < "$JAVA_TAGS_FILE"

htons() function in socket programing

htons is host-to-network short

This means it works on 16-bit short integers. i.e. 2 bytes.

This function swaps the endianness of a short.

Your number starts out at:

0001 0011 1000 1001 = 5001

When the endianness is changed, it swaps the two bytes:

1000 1001 0001 0011 = 35091

java.util.regex - importance of Pattern.compile()?

It is matter of performance and memory usage, compile and keep the complied pattern if you need to use it a lot. A typical usage of regex is to validated user input (format), and also format output data for users, in these classes, saving the complied pattern, seems quite logical as they usually called a lot.

Below is a sample validator, which is really called a lot :)

public class AmountValidator {
    //Accept 123 - 123,456 - 123,345.34
    private static final String AMOUNT_REGEX="\\d{1,3}(,\\d{3})*(\\.\\d{1,4})?|\\.\\d{1,4}";
    //Compile and save the pattern  
    private static final Pattern AMOUNT_PATTERN = Pattern.compile(AMOUNT_REGEX);


    public boolean validate(String amount){

         if (!AMOUNT_PATTERN.matcher(amount).matches()) {
            return false;
         }    
        return true;
    }    
}

As mentioned by @Alan Moore, if you have reusable regex in your code, (before a loop for example), you must compile and save pattern for reuse.

ORA-00932: inconsistent datatypes: expected - got CLOB

Take a substr of the CLOB and then convert it to a char:

UPDATE IMS_TEST 
  SET TEST_Category           = 'just testing' 
WHERE to_char(substr(TEST_SCRIPT, 1, 9))    = 'something'
  AND ID                      = '10000239';

Pivoting rows into columns dynamically in Oracle

Oracle 11g provides a PIVOT operation that does what you want.

Oracle 11g solution

select * from
(select id, k, v from _kv) 
pivot(max(v) for k in ('name', 'age', 'gender', 'status')

(Note: I do not have a copy of 11g to test this on so I have not verified its functionality)

I obtained this solution from: http://orafaq.com/wiki/PIVOT

EDIT -- pivot xml option (also Oracle 11g)
Apparently there is also a pivot xml option for when you do not know all the possible column headings that you may need. (see the XML TYPE section near the bottom of the page located at http://www.oracle.com/technetwork/articles/sql/11g-pivot-097235.html)

select * from
(select id, k, v from _kv) 
pivot xml (max(v)
for k in (any) )

(Note: As before I do not have a copy of 11g to test this on so I have not verified its functionality)

Edit2: Changed v in the pivot and pivot xml statements to max(v) since it is supposed to be aggregated as mentioned in one of the comments. I also added the in clause which is not optional for pivot. Of course, having to specify the values in the in clause defeats the goal of having a completely dynamic pivot/crosstab query as was the desire of this question's poster.

Java - Getting Data from MySQL database

Here you go :

Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection con = DriverManager.getConnection("jdbc:mysql://localhost/t", "", "");

Statement st = con.createStatement();
String sql = ("SELECT * FROM posts ORDER BY id DESC LIMIT 1;");
ResultSet rs = st.executeQuery(sql);
if(rs.next()) { 
 int id = rs.getInt("first_column_name"); 
 String str1 = rs.getString("second_column_name");
}

con.close();

In rs.getInt or rs.getString you can pass column_id starting from 1, but i prefer to pass column_name as its more informative as you don't have to look at database table for which index is what column.

UPDATE : rs.next

boolean next() throws SQLException

Moves the cursor froward one row from its current position. A ResultSet cursor is initially positioned before the first row; the first call to the method next makes the first row the current row; the second call makes the second row the current row, and so on.

When a call to the next method returns false, the cursor is positioned after the last row. Any invocation of a ResultSet method which requires a current row will result in a SQLException being thrown. If the result set type is TYPE_FORWARD_ONLY, it is vendor specified whether their JDBC driver implementation will return false or throw an SQLException on a subsequent call to next.

If an input stream is open for the current row, a call to the method next will implicitly close it. A ResultSet object's warning chain is cleared when a new row is read.

Returns: true if the new current row is valid; false if there are no more rows Throws: SQLException - if a database access error occurs or this method is called on a closed result set

reference

Difference between Constructor and ngOnInit

The Constructor is executed when the class is instantiated. It has nothing do with the angular. It is the feature of Javascript and Angular does not have the control over it

The ngOnInit is Angular specific and is called when the Angular has initialized the component with all its input properties

The @Input properties are available under the ngOnInit lifecycle hook. This will help you to do some initialization stuff like getting data from the back-end server etc to display in the view

@Input properties are shows up as undefined inside the constructor

Why does CreateProcess give error 193 (%1 is not a valid Win32 app)

Your Button2Click and Button3Click functions pass klad.xls and smimime.txt. These files most likely aren't actual executables indeed.

In order to open arbitrary files using the application associated with them, use ShellExecute

Make code in LaTeX look *nice*

The listings package is quite nice and very flexible (e.g. different sizes for comments and code).

Rails: Missing host to link to! Please provide :host parameter or set default_url_options[:host]

The above answer did not work for me, at least not as I wanted. I realised config.action_mailer.default_url_options = { host: "localhost", port: 3000 } after installing devise. Hope it will help someone with the same problem.

JSON Invalid UTF-8 middle byte

JSON data must be encoded as UTF-8, UTF-16 or UTF-32. The JSON decoder can determine the encoding by examining the first four octets of the byte stream:

       00 00 00 xx  UTF-32BE
       00 xx 00 xx  UTF-16BE
       xx 00 00 00  UTF-32LE
       xx 00 xx 00  UTF-16LE
       xx xx xx xx  UTF-8

It sounds like the server is encoding data in some illegal encoding (ISO-8859-1, windows-1252, etc.)

Is __init__.py not required for packages in Python 3.3+

Based on my experience, even with python 3.3+, an empty __init__.py is still needed sometimes. One situation is when you want to refer a subfolder as a package. For example, when I ran python -m test.foo, it didn't work until I created an empty __init__.py under the test folder. And I'm talking about 3.6.6 version here which is pretty recent.

Apart from that, even for reasons of compatibility with existing source code or project guidelines, its nice to have an empty __init__.py in your package folder.

NotificationCenter issue on Swift 3

I think it has changed again.

For posting this works in Xcode 8.2.

NotificationCenter.default.post(Notification(name:.UIApplicationWillResignActive)

R dates "origin" must be supplied

Another option is the lubridate package:

library(lubridate)

x <- 15103
as_date(x, origin = lubridate::origin)
"2011-05-09"

y <- 1442866615
as_datetime(y, origin = lubridate::origin)
"2015-09-21 20:16:55 UTC"

From the docs:

Origin is the date-time for 1970-01-01 UTC in POSIXct format. This date-time is the origin for the numbering system used by POSIXct, POSIXlt, chron, and Date classes.

Why does this CSS margin-top style not work?

Just for a quick fix, try wrapping your child elements into a div element like this -

<div id="outer">
   <div class="divadjust" style="padding-top: 1px">
      <div id="inner">
         Hello world!
      </div>
   </div>
</div>

Margin of inner div won't collapse due to the padding of 1px in-between outer and inner div. So logically you will have 1px extra space along with existing margin of inner div.

Converting string from snake_case to CamelCase in Ruby

Benchmark for pure Ruby solutions

I took every possibilities I had in mind to do it with pure ruby code, here they are :

  • capitalize and gsub

    'app_user'.capitalize.gsub(/_(\w)/){$1.upcase}
    
  • split and map using & shorthand (thanks to user3869936’s answer)

    'app_user'.split('_').map(&:capitalize).join
    
  • split and map (thanks to Mr. Black’s answer)

    'app_user'.split('_').map{|e| e.capitalize}.join
    

And here is the Benchmark for all of these, we can see that gsub is quite bad for this. I used 126 080 words.

                              user     system      total        real
capitalize and gsub  :      0.360000   0.000000   0.360000 (  0.357472)
split and map, with &:      0.190000   0.000000   0.190000 (  0.189493)
split and map        :      0.170000   0.000000   0.170000 (  0.171859)

How do I make the scrollbar on a div only visible when necessary?

try this:

<div style='overflow:auto; width:400px;height:400px;'>here is some text</div>

Android Studio how to run gradle sync manually?

I presume it is referring to Tools > Android > "Sync Project with Gradle Files" from the Android Studio main menu.

Singleton in Android

answer suggested by rakesh is great but still with some discription Singleton in Android is the same as Singleton in Java: The Singleton design pattern addresses all of these concerns. With the Singleton design pattern you can:

1) Ensure that only one instance of a class is created

2) Provide a global point of access to the object

3) Allow multiple instances in the future without affecting a singleton class's clients

A basic Singleton class example:

public class MySingleton
{
    private static MySingleton _instance;

    private MySingleton()
    {

    }

    public static MySingleton getInstance()
    {
        if (_instance == null)
        {
            _instance = new MySingleton();
        }
        return _instance;
    }
}

How can I check if a string contains a character in C#?

You can create your own extention method if you plan to use this a lot.

public static class StringExt
{
    public static bool ContainsInvariant(this string sourceString, string filter)
    {
        return sourceString.ToLowerInvariant().Contains(filter);
    }
}

example usage:

public class test
{
    public bool Foo()
    {
        const string def = "aB";
        return def.ContainsInvariant("s");
    }
}

Casting to string in JavaScript

if you are ok with null, undefined, NaN, 0, and false all casting to '' then (s ? s+'' : '') is faster.

see http://jsperf.com/cast-to-string/8

note - there are significant differences across browsers at this time.

programming a servo thru a barometer

You could define a mapping of air pressure to servo angle, for example:

def calc_angle(pressure, min_p=1000, max_p=1200):     return 360 * ((pressure - min_p) / float(max_p - min_p))  angle = calc_angle(pressure) 

This will linearly convert pressure values between min_p and max_p to angles between 0 and 360 (you could include min_a and max_a to constrain the angle, too).

To pick a data structure, I wouldn't use a list but you could look up values in a dictionary:

d = {1000:0, 1001: 1.8, ...}  angle = d[pressure] 

but this would be rather time-consuming to type out!

Default value in Doctrine

If you use yaml definition for your entity, the following works for me on a postgresql database:

Entity\Entity_name:
    type: entity
    table: table_name
    fields: 
        field_name:
            type: boolean
            nullable: false
            options:
                default: false

Getting the folder name from a path

It's also important to note that while getting a list of directory names in a loop, the DirectoryInfo class gets initialized once thus allowing only first-time call. In order to bypass this limitation, ensure you use variables within your loop to store any individual directory's name.

For example, this sample code loops through a list of directories within any parent directory while adding each found directory-name inside a List of string type:

[C#]

string[] parentDirectory = Directory.GetDirectories("/yourpath");
List<string> directories = new List<string>();

foreach (var directory in parentDirectory)
{
    // Notice I've created a DirectoryInfo variable.
    DirectoryInfo dirInfo = new DirectoryInfo(directory);

    // And likewise a name variable for storing the name.
    // If this is not added, only the first directory will
    // be captured in the loop; the rest won't.
    string name = dirInfo.Name;

    // Finally we add the directory name to our defined List.
    directories.Add(name);
}

[VB.NET]

Dim parentDirectory() As String = Directory.GetDirectories("/yourpath")
Dim directories As New List(Of String)()

For Each directory In parentDirectory

    ' Notice I've created a DirectoryInfo variable.
    Dim dirInfo As New DirectoryInfo(directory)

    ' And likewise a name variable for storing the name.
    ' If this is not added, only the first directory will
    ' be captured in the loop; the rest won't.
    Dim name As String = dirInfo.Name

    ' Finally we add the directory name to our defined List.
    directories.Add(name)

Next directory

Returning http 200 OK with error within response body

Even if I want to return a business logic error as HTTP code there is no such acceptable HTTP error code for that errors rather than using HTTP 200 because it will misrepresent the actual error.

So, HTTP 200 will be good for business logic errors. But all errors which are covered by HTTP error codes should use them.

Basically HTTP 200 means what server correctly processes user request (in case of there is no seats on the plane it is no matter because user request was correctly processed, it can even return just a number of seats available on the plane, so there will be no business logic errors at all or that business logic can be on client side. Business logic error is an abstract meaning, but HTTP error is more definite).

Convert float to string with precision & number of decimal digits specified?

The customary method for doing this sort of thing is to "print to string". In C++ that means using std::stringstream something like:

std::stringstream ss;
ss << std::fixed << std::setprecision(2) << number;
std::string mystring = ss.str();

matplotlib.pyplot will not forget previous plots - how can I flush/refresh?

I discovered that this behaviour only occurs after running a particular script, similar to the one in the question. I have no idea why it occurs.

It works (refreshes the graphs) if I put

plt.clf()
plt.cla()
plt.close()

after every plt.show()

calculating the difference in months between two dates

You won't be able to get that from a TimeSpan, because a "month" is a variable unit of measure. You'll have to calculate it yourself, and you'll have to figure out how exactly you want it to work.

For example, should dates like July 5, 2009 and August 4, 2009 yield one month or zero months difference? If you say it should yield one, then what about July 31, 2009 and August 1, 2009? Is that a month? Is it simply the difference of the Month values for the dates, or is it more related to an actual span of time? The logic for determining all of these rules is non-trivial, so you'll have to determine your own and implement the appropriate algorithm.

If all you want is simply a difference in the months--completely disregarding the date values--then you can use this:

public static int MonthDifference(this DateTime lValue, DateTime rValue)
{
    return (lValue.Month - rValue.Month) + 12 * (lValue.Year - rValue.Year);
}

Note that this returns a relative difference, meaning that if rValue is greater than lValue, then the return value will be negative. If you want an absolute difference, you can use this:

public static int MonthDifference(this DateTime lValue, DateTime rValue)
{
    return Math.Abs((lValue.Month - rValue.Month) + 12 * (lValue.Year - rValue.Year));
}

Exponentiation in Python - should I prefer ** operator instead of math.pow and math.sqrt?

Even in base Python you can do the computation in generic form

result = sum(x**2 for x in some_vector) ** 0.5

x ** 2 is surely not an hack and the computation performed is the same (I checked with cpython source code). I actually find it more readable (and readability counts).

Using instead x ** 0.5 to take the square root doesn't do the exact same computations as math.sqrt as the former (probably) is computed using logarithms and the latter (probably) using the specific numeric instruction of the math processor.

I often use x ** 0.5 simply because I don't want to add math just for that. I'd expect however a specific instruction for the square root to work better (more accurately) than a multi-step operation with logarithms.

text flowing out of div

i recently encountered this. I used: display:block;

How to remove duplicate white spaces in string using Java?

Like this:

yourString = yourString.replaceAll("\\s+", " ");

For example

System.out.println("lorem  ipsum   dolor \n sit.".replaceAll("\\s+", " "));

outputs

lorem ipsum dolor sit.

What does that \s+ mean?

\s+ is a regular expression. \s matches a space, tab, new line, carriage return, form feed or vertical tab, and + says "one or more of those". Thus the above code will collapse all "whitespace substrings" longer than one character, with a single space character.


Source: Java: Removing duplicate white spaces in strings

How to remove focus from single editText

I've tryed much to clear focus of an edit text. clearfocus() and focusable and other things never worked for me. So I came up with the idea of letting a fake edittext gain focus:

<LinearLayout
    ...
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        ...
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    <!--here comes your stuff-->

    </LinearLayout>

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/fake"
        android:textSize="1sp"/>

</LinearLayout>

then in your java code:

View view = Activity.this.getCurrentFocus();
                    if (view != null) {
                        InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
                        imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
                        fake.requestFocus();
                    }

it will hide the keyboard and remove the focus of any edittext that has it. and also as you see the fake edittext is out of screen and can't be seen

Modifying a query string without reloading the page

Building off of Fabio's answer, I created two functions that will probably be useful for anyone stumbling upon this question. With these two functions, you can call insertParam() with a key and value as an argument. It will either add the URL parameter or, if a query param already exists with the same key, it will change that parameter to the new value:

//function to remove query params from a URL
function removeURLParameter(url, parameter) {
    //better to use l.search if you have a location/link object
    var urlparts= url.split('?');   
    if (urlparts.length>=2) {

        var prefix= encodeURIComponent(parameter)+'=';
        var pars= urlparts[1].split(/[&;]/g);

        //reverse iteration as may be destructive
        for (var i= pars.length; i-- > 0;) {    
            //idiom for string.startsWith
            if (pars[i].lastIndexOf(prefix, 0) !== -1) {  
                pars.splice(i, 1);
            }
        }

        url= urlparts[0] + (pars.length > 0 ? '?' + pars.join('&') : "");
        return url;
    } else {
        return url;
    }
}

//function to add/update query params
function insertParam(key, value) {
    if (history.pushState) {
        // var newurl = window.location.protocol + "//" + window.location.host + search.pathname + '?myNewUrlQuery=1';
        var currentUrlWithOutHash = window.location.origin + window.location.pathname + window.location.search;
        var hash = window.location.hash
        //remove any param for the same key
        var currentUrlWithOutHash = removeURLParameter(currentUrlWithOutHash, key);

        //figure out if we need to add the param with a ? or a &
        var queryStart;
        if(currentUrlWithOutHash.indexOf('?') !== -1){
            queryStart = '&';
        } else {
            queryStart = '?';
        }

        var newurl = currentUrlWithOutHash + queryStart + key + '=' + value + hash
        window.history.pushState({path:newurl},'',newurl);
    }
}

Py_Initialize fails - unable to load the file system codec

The core reason is quite simple: Python does not find its modules directory, so it can of course not load encodings, too

Python doc on embedding says "Py_Initialize() calculates the module search path based upon its best guess" ... "In particular, it looks for a directory named lib/pythonX.Y"

Yet, if the modules are installed in (just) lib - relative to the python binary - above guess is wrong.

Although docs says that PYTHONHOME and PYTHONPATH are regarded, we observed that this was not the case; their actual presence or content was completely irrelevant.

The only thing that had an effect was a call to Py_SetPath() with e.g. [path-to]\lib as argument before Py_Initialize().

Sure this is only an option for an embedding scenario where one has direct access and control over the code; with a ready-made solution, special steps may be necessary to solve the issue.

Random element from string array

Just store the index generated in a variable, and then access the array using this varaible:

int idx = new Random().nextInt(fruits.length);
String random = (fruits[idx]);

P.S. I usually don't like generating new Random object per randoization - I prefer using a single Random in the program - and re-use it. It allows me to easily reproduce a problematic sequence if I later find any bug in the program.

According to this approach, I will have some variable Random r somewhere, and I will just use:

int idx = r.nextInt(fruits.length)

However, your approach is OK as well, but you might have hard time reproducing a specific sequence if you need to later on.

CSS3 Transition - Fade out effect

You can use transitions instead:

.successfully-saved.hide-opacity{
    opacity: 0;
}

.successfully-saved {
    color: #FFFFFF;
    text-align: center;

    -webkit-transition: opacity 3s ease-in-out;
    -moz-transition: opacity 3s ease-in-out;
    -ms-transition: opacity 3s ease-in-out;
    -o-transition: opacity 3s ease-in-out;
     opacity: 1;
}

How to get folder path for ClickOnce application

To find the folder location, you can just run the app, open the task manager (CTRL-SHIFT-ESC), select the app and right-click|Open file location.

Android transparent status bar and actionbar

I'm developing an app that needs to look similar in all devices with >= API14 when it comes to actionbar and statusbar customization. I've finally found a solution and since it took a bit of my time I'll share it to save some of yours. We start by using an appcompat-21 dependency.

Transparent Actionbar:

values/styles.xml:

<style name="AppTheme" parent="Theme.AppCompat.Light">
...
</style>

<style name="AppTheme.ActionBar.Transparent" parent="AppTheme">
    <item name="android:windowContentOverlay">@null</item>
    <item name="windowActionBarOverlay">true</item>
    <item name="colorPrimary">@android:color/transparent</item>
</style>

<style name="AppTheme.ActionBar" parent="AppTheme">
    <item name="windowActionBarOverlay">false</item>
    <item name="colorPrimary">@color/default_yellow</item>
</style>


values-v21/styles.xml:

<style name="AppTheme" parent="Theme.AppCompat.Light">
    ...
</style>

<style name="AppTheme.ActionBar.Transparent" parent="AppTheme">
    <item name="colorPrimary">@android:color/transparent</item>
</style>

<style name="AppTheme.ActionBar" parent="AppTheme">
    <item name="colorPrimaryDark">@color/bg_colorPrimaryDark</item>
    <item name="colorPrimary">@color/default_yellow</item>
</style>

Now you can use these themes in your AndroidManifest.xml to specify which activities will have a transparent or colored ActionBar:

    <activity
            android:name=".MyTransparentActionbarActivity"
            android:theme="@style/AppTheme.ActionBar.Transparent"/>

    <activity
            android:name=".MyColoredActionbarActivity"
            android:theme="@style/AppTheme.ActionBar"/>

enter image description here enter image description here enter image description here enter image description here enter image description here

Note: in API>=21 to get the Actionbar transparent you need to get the Statusbar transparent too, otherwise will not respect your colour styles and will stay light-grey.



Transparent Statusbar (only works with API>=19):
This one it's pretty simple just use the following code:

protected void setStatusBarTranslucent(boolean makeTranslucent) {
        if (makeTranslucent) {
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        } else {
            getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        }
    }

But you'll notice a funky result: enter image description here

This happens because when the Statusbar is transparent the layout will use its height. To prevent this we just need to:

SOLUTION ONE:
Add this line android:fitsSystemWindows="true" in your layout view container of whatever you want to be placed bellow the Actionbar:

    ...
        <LinearLayout
                android:fitsSystemWindows="true"
                android:layout_width="match_parent"
                android:layout_height="match_parent">
            ...
        </LinearLayout>
    ...

SOLUTION TWO:
Add a few lines to our previous method:

protected void setStatusBarTranslucent(boolean makeTranslucent) {
        View v = findViewById(R.id.bellow_actionbar);
        if (v != null) {
            int paddingTop = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT ? MyScreenUtils.getStatusBarHeight(this) : 0;
            TypedValue tv = new TypedValue();
            getTheme().resolveAttribute(android.support.v7.appcompat.R.attr.actionBarSize, tv, true);
            paddingTop += TypedValue.complexToDimensionPixelSize(tv.data, getResources().getDisplayMetrics());
            v.setPadding(0, makeTranslucent ? paddingTop : 0, 0, 0);
        }

        if (makeTranslucent) {
            getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        } else {
            getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        }
    }

Where R.id.bellow_actionbar will be the layout container view id of whatever we want to be placed bellow the Actionbar:

...
    <LinearLayout
            android:id="@+id/bellow_actionbar"
            android:layout_width="match_parent"
            android:layout_height="match_parent">
        ...
    </LinearLayout>
...

enter image description here

So this is it, it think I'm not forgetting something. In this example I didn't use a Toolbar but I think it'll have the same result. This is how I customize my Actionbar:

@Override
    protected void onCreate(Bundle savedInstanceState) {
        View vg = getActionBarView();
        getWindow().requestFeature(vg != null ? Window.FEATURE_ACTION_BAR : Window.FEATURE_NO_TITLE);

        super.onCreate(savedInstanceState);
        setContentView(getContentView());

        if (vg != null) {
            getSupportActionBar().setCustomView(vg, new ActionBar.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
            getSupportActionBar().setDisplayShowCustomEnabled(true);
            getSupportActionBar().setDisplayShowHomeEnabled(false);
            getSupportActionBar().setDisplayShowTitleEnabled(false);
            getSupportActionBar().setDisplayUseLogoEnabled(false);
        }
        setStatusBarTranslucent(true);
    }

Note: this is an abstract class that extends ActionBarActivity
Hope it helps!

How to output numbers with leading zeros in JavaScript?

From https://gist.github.com/1180489

function pad(a, b){
  return(1e15 + a + '').slice(-b);
}

With comments:

function pad(
  a, // the number to convert 
  b // number of resulting characters
){
  return (
    1e15 + a + // combine with large number
    "" // convert to string
  ).slice(-b) // cut leading "1"
}

Installing SetupTools on 64-bit Windows

Yes, you are correct, the issue is with 64-bit Python and 32-bit installer for setuptools.

The best way to get 64-bit setuptools installed on Windows is to download ez_setup.py to C:\Python27\Scripts and run it. It will download appropriate 64-bit .egg file for setuptools and install it for you.

Source: http://pypi.python.org/pypi/setuptools

P.S. I'd recommend against using 3rd party 64-bit .exe setuptools installers or manipulating registry

Calling a function when ng-repeat has finished

Very easy, this is how I did it.

_x000D_
_x000D_
.directive('blockOnRender', function ($blockUI) {_x000D_
    return {_x000D_
        restrict: 'A',_x000D_
        link: function (scope, element, attrs) {_x000D_
            _x000D_
            if (scope.$first) {_x000D_
                $blockUI.blockElement($(element).parent());_x000D_
            }_x000D_
            if (scope.$last) {_x000D_
                $blockUI.unblockElement($(element).parent());_x000D_
            }_x000D_
        }_x000D_
    };_x000D_
})
_x000D_
_x000D_
_x000D_

How do I connect to a SQL Server 2008 database using JDBC?

You can use this :

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class ConnectMSSQLServer
{
   public void dbConnect(String db_connect_string,
            String db_userid,
            String db_password)
   {
      try {
         Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
         Connection conn = DriverManager.getConnection(db_connect_string,
                  db_userid, db_password);
         System.out.println("connected");
         Statement statement = conn.createStatement();
         String queryString = "select * from sysobjects where type='u'";
         ResultSet rs = statement.executeQuery(queryString);
         while (rs.next()) {
            System.out.println(rs.getString(1));
         }
      } catch (Exception e) {
         e.printStackTrace();
      }
   }

   public static void main(String[] args)
   {
      ConnectMSSQLServer connServer = new ConnectMSSQLServer();
      connServer.dbConnect("jdbc:sqlserver://<hostname>", "<user>",
               "<password>");
   }
}

How can I get the CheckBoxList selected values, what I have doesn't seem to work C#.NET/VisualWebPart

// Page.aspx //

// To count checklist item

  int a = ChkMonth.Items.Count;
        int count = 0;

        for (var i = 0; i < a; i++)
        {
            if (ChkMonth.Items[i].Selected == true)
            {
                count++;
            }
        }

// Page.aspx.cs //

  // To access checkbox list item's value //
   string YrStrList = "";
        foreach (ListItem listItem in ChkMonth.Items)
        {
            if (listItem.Selected)
            {
                YrStrList = YrStrList + "'" + listItem.Value + "'" + ",";
            }

        }

        sMonthStr = YrStrList.ToString();

Efficiently replace all accented characters in a string?

Basing on existing answers and some suggestions, I've created this one:

String.prototype.removeAccents = function() {

    var removalMap = {
        'A'  : /[A?AÀÁÂ????ÃAA??????ÄA?Å?A??????A]/g,
        'AA' : /[?]/g,
        'AE' : /[Æ??]/g,
        'AO' : /[?]/g,
        'AU' : /[?]/g,
        'AV' : /[??]/g,
        'AY' : /[?]/g,
        'B'  : /[B?B??????]/g,
        'C'  : /[C?CCCCCÇ????]/g,
        'D'  : /[D?D?D????Ð??Ð?]/g,
        'DZ' : /[??]/g,
        'Dz' : /[??]/g,
        'E'  : /[E?EÈÉÊ?????E??EEË?E??????E????]/g,
        'F'  : /[F?F?ƒ?]/g,
        'G'  : /[G?G?G?GGGGG????]/g,
        'H'  : /[H?HH??????H???]/g,
        'I'  : /[I?IÌÍÎIIIIÏ??I???I?I]/g,
        'J'  : /[J?JJ?]/g,
        'K'  : /[K?K?K?K???????]/g,
        'L'  : /[L?L?LL??L??L??????]/g,
        'LJ' : /[?]/g,
        'Lj' : /[?]/g,
        'M'  : /[M?M?????]/g,
        'N'  : /[N?N?NÑ?N?N??????]/g,
        'NJ' : /[?]/g,
        'Nj' : /[?]/g,
        'O'  : /[O?OÒÓÔ????Õ???O??O??Ö??OO??O???????OOØ??O??]/g,
        'OI' : /[?]/g,
        'OO' : /[?]/g,
        'OU' : /[?]/g,
        'P'  : /[P?P???????]/g,
        'Q'  : /[Q?Q???]/g,
        'R'  : /[R?RR?R????R??????]/g,
        'S'  : /[S?S?S?S?Š????S???]/g,
        'T'  : /[T?T?T??T??T?T??]/g,
        'TZ' : /[?]/g,
        'U'  : /[U?UÙÚÛU?U?UÜUUUU?UUU??U???????U???]/g,
        'V'  : /[V?V?????]/g,
        'VY' : /[?]/g,
        'W'  : /[W?W??W????]/g,
        'X'  : /[X?X??]/g,
        'Y'  : /[Y?Y?ÝY???Ÿ?????]/g,
        'Z'  : /[Z?ZZ?ZŽ???????]/g,
        'a'  : /[a?a?àáâ????ãaa??????äa?å?a??????a??]/g,
        'aa' : /[?]/g,
        'ae' : /[æ??]/g,
        'ao' : /[?]/g,
        'au' : /[?]/g,
        'av' : /[??]/g,
        'ay' : /[?]/g,
        'b'  : /[b?b???b??]/g,
        'c'  : /[c?cccccç?????]/g,
        'd'  : /[d?d?d????d????]/g,
        'dz' : /[??]/g,
        'e'  : /[e?eèéê?????e??eeë?e??????e?????]/g,
        'f'  : /[f?f?ƒ?]/g,
        'g'  : /[g?g?g?ggggg????]/g,
        'h'  : /[h?hh???????h???]/g,
        'hv' : /[?]/g,
        'i'  : /[i?iìíîiiiï??i???i??i]/g,
        'j'  : /[j?jjj?]/g,
        'k'  : /[k?k?k?k???????]/g,
        'l'  : /[l?l?ll??l???ll?????]/g,
        'lj' : /[?]/g,
        'm'  : /[m?m?????]/g,
        'n'  : /[n?n?nñ?n?n???????]/g,
        'nj' : /[?]/g,
        'o'  : /[o?oòóô????õ???o??o??ö??oo??o???????ooø?????]/g,
        'oi' : /[?]/g,
        'ou' : /[?]/g,
        'oo' : /[?]/g,
        'p'  : /[p?p???????]/g,
        'q'  : /[q?q???]/g,
        'r'  : /[r?rr?r????r??????]/g,
        's'  : /[s?sßs?s?š????s????]/g,
        't'  : /[t?t??t??t??t????]/g,
        'tz' : /[?]/g,
        'u'  : /[u?uùúûu?u?uüuuuu?uuu??u???????u???]/g,
        'v'  : /[v?v?????]/g,
        'vy' : /[?]/g,
        'w'  : /[w?w??w?????]/g,
        'x'  : /[x?x??]/g,
        'y'  : /[y?y?ýy???ÿ??????]/g,
        'z'  : /[z?zz?zž??z????]/g,
    };

    var str = this;

    for(var latin in removalMap) {
      var nonLatin = removalMap[latin];
      str = str.replace(nonLatin , latin);
    }

    return str;
}

It uses real chars instead of unicode list and works well.

You can use it like

"aaa".removeAccents(); // returns "aaa"

You can easily convert this function to not be string prototype. However, as I'm fan of using string prototype in such cases, you'll have to do it yourself.

How to add Android Support Repository to Android Studio?

Found a solution.

1) Go to where your SDK is located that android studio/eclipse is using. If you are using Android studio, go to extras\android\m2repository\com\android\support\. If you are using eclipse, go to \extras\android\support\

2) See what folders you have, for me I had gridlayout-v7, support-v4 and support-v13.

3) click into support-v4 and see what number the following folder is, mine was named 13.0

Since you are using "com.android.support:support-v4:18.0.+", change this to reflect what version you have, for example I have support-v4 so first part v4 stays the same. Since the next path is 13.0, change your 18.0 to:

"com.android.support:support-v4:13.0.+"

This worked for me, hope it helps!

Update:

I noticed I had android studio set up with the wrong SDK which is why originally had difficulty updating! The path should be C:\Users\Username\AppData\Local\Android\android-sdk\extras\

Also note, if your SDK is up to date, the code will be:

"com.android.support:support-v4:19.0.+"

Text overwrite in visual studio 2010

I'm using Visual Studio 2019. I used the shortcut below:

Shift + Insert

Is it possible to use global variables in Rust?

Look at the const and static section of the Rust book.

You can use something as follows:

const N: i32 = 5; 

or

static N: i32 = 5;

in global space.

But these are not mutable. For mutability, you could use something like:

static mut N: i32 = 5;

Then reference them like:

unsafe {
    N += 1;

    println!("N: {}", N);
}

wget ssl alert handshake failure

It works from here with same OpenSSL version, but a newer version of wget (1.15). Looking at the Changelog there is the following significant change regarding your problem:

1.14: Add support for TLS Server Name Indication.

Note that this site does not require SNI. But www.coursera.org requires it. And if you would call wget with -v --debug (as I've explicitly recommended in my comment!) you will see:

$ wget https://class.coursera.org
...
HTTP request sent, awaiting response...
  HTTP/1.1 302 Found
...
Location: https://www.coursera.org/ [following]
...
Connecting to www.coursera.org (www.coursera.org)|54.230.46.78|:443... connected.
OpenSSL: error:14077410:SSL routines:SSL23_GET_SERVER_HELLO:sslv3 alert handshake failure
Unable to establish SSL connection.

So the error actually happens with www.coursera.org and the reason is missing support for SNI. You need to upgrade your version of wget.

Why can't I enter a string in Scanner(System.in), when calling nextLine()-method?

This is because after the nextInt() finished it's execution, when the nextLine() method is called, it scans the newline character of which was present after the nextInt(). You can do this in either of the following ways:

  1. You can use another nextLine() method just after the nextInt() to move the scanner past the newline character.
  2. You can use different Scanner objects for scanning the integer and string (You can name them scan1 and scan2).
  3. You can use the next method on the scanner object as

    scan.next();

Error: package or namespace load failed for ggplot2 and for data.table

I had the same problem with the package "tidyverse". I solved the problem with 1. uninstalling the package "Rcpp" and "tidyverse" 2. reinstalling "Rcpp" and answering the following questions during the installation process:

Do you want to install from sources the package which needs compilation? (Yes/no/cancel)

with

no
  1. reinstalling "tidyverse".

Stopping a windows service when the stop option is grayed out

Open command prompt with admin access and type the following commands there .

a)

tasklist

it displays list of all available services . There you can see the service you want to stop/start/restart . Remember PID value of the service you want to force stop.

b) Now type

taskkill /f /PID [PID value of the service] 

and press enter. On success you will get the message “SUCCESS: The process with PID has been terminated”.

Ex : taskkill /f /PID 5088

This will forcibly kill the frozen service. You can now return to Server Manager and restart the service.

Cross Browser Flash Detection in Javascript

SWFObject is very reliable. I have used it without trouble for quite a while.

Echoing the last command run in Bash?

history | tail -2 | head -1 | cut -c8-999

tail -2 returns the last two command lines from history head -1 returns just first line cut -c8-999 returns just command line, removing PID and spaces.

Is it possible to indent JavaScript code in Notepad++?

Could you use online services like this ?

Update: (as per request)

Google chrome will do this also http://cristian-radulescu.ro/article/pretty-print-javascript-with-google-chrome.html

change text of button and disable button in iOS

Assuming that the button is a UIButton:

UIButton *button = …;
[button setEnabled:NO]; // disables
[button setTitle:@"Foo" forState:UIControlStateNormal]; // sets text

See the documentation for UIButton.

How do you plot bar charts in gnuplot?

I recommend Derek Bruening's bar graph generator Perl script. Available at http://www.burningcutlery.com/derek/bargraph/

CSS for grabbing cursors (drag & drop)

The closed hand cursor is not 16x16. If you would need them in the same dimensions, here you have both of them in 16x16 px

opened hand closed hand

Or if you need original cursors:

https://www.google.com/intl/en_ALL/mapfiles/openhand.cur https://www.google.com/intl/en_ALL/mapfiles/closedhand.cur

onCreateOptionsMenu inside Fragments

Set setHasMenuOptions(true) works if application has a theme with Actionbar such as Theme.MaterialComponents.DayNight.DarkActionBar or Activity has it's own Toolbar, otherwise onCreateOptionsMenu in fragment does not get called.

If you want to use standalone Toolbar you either need to get activity and set your Toolbar as support action bar with

(requireActivity() as? MainActivity)?.setSupportActionBar(toolbar)

which lets your fragment onCreateOptionsMenu to be called.

Other alternative is, you can inflate your Toolbar's own menu with toolbar.inflateMenu(R.menu.YOUR_MENU) and item listener with

toolbar.setOnMenuItemClickListener {
   // do something
   true
}

jQuery UI themes and HTML tables

I've got a one liner to make HTML Tables look BootStrapped:

<table class="table table-striped table-bordered table-hover">

The theme suits other controls and it supports alternate row highlighting.

Read url to string in few lines of java code

Now that some time has passed since the original answer was accepted, there's a better approach:

String out = new Scanner(new URL("http://www.google.com").openStream(), "UTF-8").useDelimiter("\\A").next();

If you want a slightly fuller implementation, which is not a single line, do this:

public static String readStringFromURL(String requestURL) throws IOException
{
    try (Scanner scanner = new Scanner(new URL(requestURL).openStream(),
            StandardCharsets.UTF_8.toString()))
    {
        scanner.useDelimiter("\\A");
        return scanner.hasNext() ? scanner.next() : "";
    }
}

Setting PayPal return URL and making it auto return?

on the checkout page, look for the 'cancel_return' hidden form element:

set the value of the cancel_return form element to the URL you wish to return to:

Best C/C++ Network Library

Aggregated List of Libraries

AngularJS: ng-model not binding to ng-checked for checkboxes

ngModel and ngChecked are not meant to be used together.

ngChecked is expecting an expression, so by saying ng-checked="true", you're basically saying that the checkbox will always be checked by default.

You should be able to just use ngModel, tied to a boolean property on your model. If you want something else, then you either need to use ngTrueValue and ngFalseValue (which only support strings right now), or write your own directive.

What is it exactly that you're trying to do? If you just want the first checkbox to be checked by default, you should change your model -- item1: true,.

Edit: You don't have to submit your form to debug the current state of the model, btw, you can just dump {{testModel}} into your HTML (or <pre>{{testModel|json}}</pre>). Also your ngModel attributes can be simplified to ng-model="testModel.item1".

http://plnkr.co/edit/HtdOok8aieBjT5GFZOb3?p=preview

How do I ignore files in a directory in Git?

If you want to put a .gitignore file at the top level and make it work for any folder below it use /**/.

E.g. to ignore all *.map files in a /src/main/ folder and sub-folders use:

/src/main/**/*.map

How can Perl's print add a newline by default?

If you're stuck with pre-5.10, then the solutions provided above will not fully replicate the say function. For example

sub say { print @_, "\n"; }

Will not work with invocations such as

say for @arr;

or

for (@arr) {
    say;
}

... because the above function does not act on the implicit global $_ like print and the real say function.

To more closely replicate the perl 5.10+ say you want this function

sub say {
    if (@_) { print @_, "\n"; }
    else { print $_, "\n"; }
}

Which now acts like this

my @arr = qw( alpha beta gamma );
say @arr;
# OUTPUT
# alphabetagamma
#
say for @arr;
# OUTPUT
# alpha
# beta
# gamma
#

The say builtin in perl6 behaves a little differently. Invoking it with say @arr or @arr.say will not just concatenate the array items, but instead prints them separated with the list separator. To replicate this in perl5 you would do this

sub say {
    if (@_) { print join($", @_) . "\n"; }
    else { print $_ . "\n"; }
}

$" is the global list separator variable, or if you're using English.pm then is is $LIST_SEPARATOR

It will now act more like perl6, like so

say @arr;
# OUTPUT
# alpha beta gamma
#

How do I specify local .gem files in my Gemfile?

I found it easiest to run my own gem server using geminabox

See these simple instructions.

Count number of records returned by group by

Can you execute the following code below. It worked in Oracle.

SELECT COUNT(COUNT(*))
FROM temptable
GROUP BY column_1, column_2, column_3, column_4

Google Maps API v3 marker with label

I can't guarantee it's the simplest, but I like MarkerWithLabel. As shown in the basic example, CSS styles define the label's appearance and options in the JavaScript define the content and placement.

 .labels {
   color: red;
   background-color: white;
   font-family: "Lucida Grande", "Arial", sans-serif;
   font-size: 10px;
   font-weight: bold;
   text-align: center;
   width: 60px;     
   border: 2px solid black;
   white-space: nowrap;
 }

JavaScript:

 var marker = new MarkerWithLabel({
   position: homeLatLng,
   draggable: true,
   map: map,
   labelContent: "$425K",
   labelAnchor: new google.maps.Point(22, 0),
   labelClass: "labels", // the CSS class for the label
   labelStyle: {opacity: 0.75}
 });

The only part that may be confusing is the labelAnchor. By default, the label's top left corner will line up to the marker pushpin's endpoint. Setting the labelAnchor's x-value to half the width defined in the CSS width property will center the label. You can make the label float above the marker pushpin with an anchor point like new google.maps.Point(22, 50).

In case access to the links above are blocked, I copied and pasted the packed source of MarkerWithLabel into this JSFiddle demo. I hope JSFiddle is allowed in China :|

Why doesn't indexOf work on an array IE8?

Versions of IE before IE9 don't have an .indexOf() function for Array, to define the exact spec version, run this before trying to use it:

if (!Array.prototype.indexOf)
{
  Array.prototype.indexOf = function(elt /*, from*/)
  {
    var len = this.length >>> 0;

    var from = Number(arguments[1]) || 0;
    from = (from < 0)
         ? Math.ceil(from)
         : Math.floor(from);
    if (from < 0)
      from += len;

    for (; from < len; from++)
    {
      if (from in this &&
          this[from] === elt)
        return from;
    }
    return -1;
  };
}

This is the version from MDN, used in Firefox/SpiderMonkey. In other cases such as IE, it'll add .indexOf() in the case it's missing... basically IE8 or below at this point.

Why am I suddenly getting a "Blocked loading mixed active content" issue in Firefox?

@Blender Comment is the best approach. Never hard code the protocol anywhere in the code as it will be difficult to change if you move from http to https. Since you need to manually edit and update all the files.

This is always better as it automatically detect the protocol.

src="//code.jquery.com

Errno 10060] A connection attempt failed because the connected party did not properly respond after a period of time

As ping works, but telnetto port 80 does not, the HTTP port 80 is closed on your machine. I assume that your browser's HTTP connection goes through a proxy (as browsing works, how else would you read stackoverflow?). You need to add some code to your python program, that handles the proxy, like described here:

Using an HTTP PROXY - Python

WAMP server, localhost is not working

If you have skype installed, close it completely.

If you have sql server installed, go to:

Control panel -> Administrative Tools -> Services

And stop SQL Server Reporting Services

Port 80 must be free now. Click on Wamp icon -> Restart All Services

The name 'controlname' does not exist in the current context

I had the same error message. My code was error-free and working perfectly, then I decided to go back and rename one of my buttons and suddenly it's giving me a compile error accompanied by that blue squiggly underline saying that the control doesn't exist in current context...

Turns out Visual Studio was being dumb, as the problem was related to the backup files I had made of my aspx.cs class. I deleted those and the errors went away.

How to pass multiple parameters from ajax to mvc controller?

Try this:

var req={StrContactDetails:'data',IsPrimary:'True'}

$.ajax({
                   type: 'POST',
                   data: req,
                   url: '@url.Action("SaveEmergencyContact","Dhp")',
                   contentType: "application/json; charset=utf-8",
                   dataType: "json",
                   data: JSON.stringify(req),
                   success: function (data) {
                       alert("Success");
                   },
                   error: function (ob, errStr) {
                       alert("An error occured.Please try after sometime.");
                   }
               });

http://api.jquery.com/jquery.ajax/

Fit background image to div

You can use this attributes:

background-size: contain;
background-repeat: no-repeat;

and you code is then like this:

 <div style="text-align:center;background-image: url(/media/img_1_bg.jpg); background-size: contain;
background-repeat: no-repeat;" id="mainpage">

GCC -fPIC option

A minor addition to the answers already posted: object files not compiled to be position independent are relocatable; they contain relocation table entries.

These entries allow the loader (that bit of code that loads a program into memory) to rewrite the absolute addresses to adjust for the actual load address in the virtual address space.

An operating system will try to share a single copy of a "shared object library" loaded into memory with all the programs that are linked to that same shared object library.

Since the code address space (unlike sections of the data space) need not be contiguous, and because most programs that link to a specific library have a fairly fixed library dependency tree, this succeeds most of the time. In those rare cases where there is a discrepancy, yes, it may be necessary to have two or more copies of a shared object library in memory.

Obviously, any attempt to randomize the load address of a library between programs and/or program instances (so as to reduce the possibility of creating an exploitable pattern) will make such cases common, not rare, so where a system has enabled this capability, one should make every attempt to compile all shared object libraries to be position independent.

Since calls into these libraries from the body of the main program will also be made relocatable, this makes it much less likely that a shared library will have to be copied.

Validating with an XML schema in Python

An example of a simple validator in Python3 using the popular library lxml

Installation lxml

pip install lxml

If you get an error like "Could not find function xmlCheckVersion in library libxml2. Is libxml2 installed?", try to do this first:

# Debian/Ubuntu
apt-get install python-dev python3-dev libxml2-dev libxslt-dev

# Fedora 23+
dnf install python-devel python3-devel libxml2-devel libxslt-devel

The simplest validator

Let's create simplest validator.py

from lxml import etree

def validate(xml_path: str, xsd_path: str) -> bool:

    xmlschema_doc = etree.parse(xsd_path)
    xmlschema = etree.XMLSchema(xmlschema_doc)

    xml_doc = etree.parse(xml_path)
    result = xmlschema.validate(xml_doc)

    return result

then write and run main.py

from validator import validate

if validate("path/to/file.xml", "path/to/scheme.xsd"):
    print('Valid! :)')
else:
    print('Not valid! :(')

A little bit of OOP

In order to validate more than one file, there is no need to create an XMLSchema object every time, therefore:

validator.py

from lxml import etree

class Validator:

    def __init__(self, xsd_path: str):
        xmlschema_doc = etree.parse(xsd_path)
        self.xmlschema = etree.XMLSchema(xmlschema_doc)

    def validate(self, xml_path: str) -> bool:
        xml_doc = etree.parse(xml_path)
        result = self.xmlschema.validate(xml_doc)

        return result

Now we can validate all files in the directory as follows:

main.py

import os
from validator import Validator

validator = Validator("path/to/scheme.xsd")

# The directory with XML files
XML_DIR = "path/to/directory"

for file_name in os.listdir(XML_DIR):
    print('{}: '.format(file_name), end='')

    file_path = '{}/{}'.format(XML_DIR, file_name)

    if validator.validate(file_path):
        print('Valid! :)')
    else:
        print('Not valid! :(')

For more options read here: Validation with lxml

Java recursive Fibonacci sequence

For fibonacci recursive solution, it is important to save the output of smaller fibonacci numbers, while retrieving the value of larger number. This is called "Memoizing".

Here is a code that use memoizing the smaller fibonacci values, while retrieving larger fibonacci number. This code is efficient and doesn't make multiple requests of same function.

import java.util.HashMap;

public class Fibonacci {
  private HashMap<Integer, Integer> map;
  public Fibonacci() {
    map = new HashMap<>();
  }
  public int findFibonacciValue(int number) {
    if (number == 0 || number == 1) {
      return number;
    }
    else if (map.containsKey(number)) {
      return map.get(number);
    }
    else {
      int fibonacciValue = findFibonacciValue(number - 2) + findFibonacciValue(number - 1);
      map.put(number, fibonacciValue);
      return fibonacciValue;
    }
  }
}

IE Enable/Disable Proxy Settings via Registry

modifying the proxy value under

[HKEY_USERS\<your SID>\Software\Microsoft\Windows\CurrentVersion\Internet Settings]

doesnt need to restart ie

How do I set a fixed background image for a PHP file?

You should consider have other php files included if you're going to derive a website from it. Instead of doing all the css/etc in that file, you can do

<head>
    <?php include_once('C:\Users\George\Documents\HTML\style.css'); ?>
    <title>Title</title>
</hea>

Then you can have a separate CSS file that is just being pulled into your php file. It provides some "neater" coding.

Prevent form redirect OR refresh on submit?

An alternative solution would be to not use form tag and handle click event on submit button through jquery. This way there wont be any page refresh but at the same time there is a downside that "enter" button for submission wont work and also on mobiles you wont get a go button( a style in some mobiles). So stick to use of form tag and use the accepted answer.

How can prevent a PowerShell window from closing so I can see the error?

You basically have 3 options to prevent the PowerShell Console window from closing, that I describe in more detail on my blog post.

  1. One-time Fix: Run your script from the PowerShell Console, or launch the PowerShell process using the -NoExit switch. e.g. PowerShell -NoExit "C:\SomeFolder\SomeScript.ps1"
  2. Per-script Fix: Add a prompt for input to the end of your script file. e.g. Read-Host -Prompt "Press Enter to exit"
  3. Global Fix: Change your registry key to always leave the PowerShell Console window open after the script finishes running. Here's the 2 registry keys that would need to be changed:

    ? Open With ? Windows PowerShell
    When you right-click a .ps1 file and choose Open With

    Registry Key: HKEY_CLASSES_ROOT\Applications\powershell.exe\shell\open\command

    Default Value:

    "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" "%1"
    

    Desired Value:

    "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" "& \"%1\""
    

    ? Run with PowerShell
    When you right-click a .ps1 file and choose Run with PowerShell (shows up depending on which Windows OS and Updates you have installed).

    Registry Key: HKEY_CLASSES_ROOT\Microsoft.PowerShellScript.1\Shell\0\Command

    Default Value:

    "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" "-Command" "if((Get-ExecutionPolicy ) -ne 'AllSigned') { Set-ExecutionPolicy -Scope Process Bypass }; & '%1'"
    

    Desired Value:

    "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -NoExit "-Command" "if((Get-ExecutionPolicy ) -ne 'AllSigned') { Set-ExecutionPolicy -Scope Process Bypass }; & \"%1\""
    

You can download a .reg file from my blog to modify the registry keys for you if you don't want to do it manually.

It sounds like you likely want to use option #2. You could even wrap your whole script in a try block, and only prompt for input if an error occurred, like so:

try
{
    # Do your script's stuff
}
catch
{
    Write-Error $_.Exception.ToString()
    Read-Host -Prompt "The above error occurred. Press Enter to exit."
}

500 Internal Server Error for php file not for html

A PHP file must have permissions set to 644. Any folder containing PHP files and PHP access (to upload files, for example) must have permissions set to 755. PHP will run a 500 error when dealing with any file or folder that has permissions set to 777!

How to resolve Nodejs: Error: ENOENT: no such file or directory

Its happened with me. I deletes some css files by mistake and then copied back. This error appeared at that time. So i restart all my dockers and other servers and then it went away, Perhaps this help some one :)

Place a button right aligned

_x000D_
_x000D_
<div style = "display: flex; justify-content:flex-end">
    <button>Click me!</button>
</div>
_x000D_
_x000D_
_x000D_

<div style = "display: flex; justify-content: flex-end">
    <button>Click me!</button>
</div>

Better way to find index of item in ArrayList?

The best way to find the position of item in the list is by using Collections interface,

Eg,

List<Integer> sampleList = Arrays.asList(10,45,56,35,6,7);
Collections.binarySearch(sampleList, 56);

Output : 2

Get current AUTO_INCREMENT value for any table

Query to check percentage "usage" of AUTO_INCREMENT for all tables of one given schema (except columns with type bigint unsigned):

SELECT 
  c.TABLE_NAME,
  c.COLUMN_TYPE,
  c.MAX_VALUE,
  t.AUTO_INCREMENT,
  IF (c.MAX_VALUE > 0, ROUND(100 * t.AUTO_INCREMENT / c.MAX_VALUE, 2), -1) AS "Usage (%)" 
FROM 
  (SELECT 
     TABLE_SCHEMA,
     TABLE_NAME,
     COLUMN_TYPE,
     CASE 
        WHEN COLUMN_TYPE LIKE 'tinyint(1)' THEN 127
        WHEN COLUMN_TYPE LIKE 'tinyint(1) unsigned' THEN 255
        WHEN COLUMN_TYPE LIKE 'smallint(%)' THEN 32767
        WHEN COLUMN_TYPE LIKE 'smallint(%) unsigned' THEN 65535
        WHEN COLUMN_TYPE LIKE 'mediumint(%)' THEN 8388607
        WHEN COLUMN_TYPE LIKE 'mediumint(%) unsigned' THEN 16777215
        WHEN COLUMN_TYPE LIKE 'int(%)' THEN 2147483647
        WHEN COLUMN_TYPE LIKE 'int(%) unsigned' THEN 4294967295
        WHEN COLUMN_TYPE LIKE 'bigint(%)' THEN 9223372036854775807
        WHEN COLUMN_TYPE LIKE 'bigint(%) unsigned' THEN 0
        ELSE 0
     END AS "MAX_VALUE" 
   FROM 
     INFORMATION_SCHEMA.COLUMNS
     WHERE EXTRA LIKE '%auto_increment%'
   ) c

   JOIN INFORMATION_SCHEMA.TABLES t ON (t.TABLE_SCHEMA = c.TABLE_SCHEMA AND t.TABLE_NAME = c.TABLE_NAME)

WHERE
 c.TABLE_SCHEMA = 'YOUR_SCHEMA' 
ORDER BY
 `Usage (%)` DESC;

How can I get all the request headers in Django?

request.META.get('HTTP_AUTHORIZATION') /python3.6/site-packages/rest_framework/authentication.py

you can get that from this file though...

file_get_contents() how to fix error "Failed to open stream", "No such file"

Why don't you use cURL ?

$yourkey="your api key";
$url="https://prod.api.pvp.net/api/lol/euw/v1.1/game/by-summoner/20986461/recent?api_key=$yourkey";
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);

$auth = curl_exec($curl);
if($auth)
{
$json = json_decode($auth); 
print_r($json);
}
}

Attaching click to anchor tag in angular

I had to combine several of the answers to get a working solution.

This solution will:

  • Style the link with the appropriate 'a' styles.
  • Call the desired function.
  • Not navigate to http://mySite/#

    <a href="#" (click)="!!functionToCall()">Link</a>

The conversion of a datetime2 data type to a datetime data type resulted in an out-of-range value

It looks like you are using entity framework. My solution was to switch all datetime columns to datetime2, and use datetime2 for any new columns, in other words make EF use datetime2 by default. Add this to the OnModelCreating method on your context:

modelBuilder.Properties<DateTime>().Configure(c => c.HasColumnType("datetime2"));

That will get all the DateTime and DateTime? properties on all the entities in your model.

Use formula in custom calculated field in Pivot Table

Some of it is possible, specifically accessing subtotals:

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

enter image description here

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

Source: http://datapigtechnologies.com/blog/index.php/excel-2010-pivottable-subtotals/

Getting the source of a specific image element with jQuery

var src = $('img.conversation_img[alt="example"]').attr('src');

If you have multiple matching elements only the src of the first one will be returned.

Can I change the viewport meta tag in mobile safari on the fly?

This has been answered for the most part, but I will expand...

Step 1

My goal was to enable zoom at certain times, and disable it at others.

// enable pinch zoom
var $viewport = $('head meta[name="viewport"]');    
$viewport.attr('content', 'width=device-width, initial-scale=1, maximum-scale=4');

// ...later...

// disable pinch zoom
$viewport.attr('content', 'width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no');

Step 2

The viewport tag would update, but pinch zoom was still active!! I had to find a way to get the page to pick up the changes...

It's a hack solution, but toggling the opacity of body did the trick. I'm sure there are other ways to accomplish this, but here's what worked for me.

// after updating viewport tag, force the page to pick up changes           
document.body.style.opacity = .9999;
setTimeout(function(){
    document.body.style.opacity = 1;
}, 1);

Step 3

My problem was mostly solved at this point, but not quite. I needed to know the current zoom level of the page so I could resize some elements to fit on the page (think of map markers).

// check zoom level during user interaction, or on animation frame
var currentZoom = $document.width() / window.innerWidth;

I hope this helps somebody. I spent several hours banging my mouse before finding a solution.

Find and kill a process in one line using bash and regex

If pkill -f csp_build.py doesn't kill the process you can add -9 to send a kill signall which will not be ignored. i.e. pkill -9 -f csp_build.py

Fix GitLab error: "you are not allowed to push code to protected branches on this project"?

I experienced the same problem on my repository. I'm the master of the repository, but I had such an error.

I've unprotected my project and then re-protected again, and the error is gone.

We had upgraded the gitlab version between my previous push and the problematic one. I suppose that this upgrade has created the bug.

Avoid line break between html elements

CSS for that td: white-space: nowrap; should solve it.

Zoom to fit all markers in Mapbox or Leaflet

Leaflet also has LatLngBounds that even has an extend function, just like google maps.

http://leafletjs.com/reference.html#latlngbounds

So you could simply use:

var latlngbounds = new L.latLngBounds();

The rest is exactly the same.

Open directory using C

Parameters passed to the C program executable is nothing but an array of string(or character pointer),so memory would have been already allocated for these input parameter before your program access these parameters,so no need to allocate buffer,and that way you can avoid error handling code in your program as well(Reduce chances of segfault :)).

GIT clone repo across local file system in windows

Either enter absolute paths or relative paths.

For example the first one below uses absolute paths :

(this is from inside the folder which contains the repository and the backup as subfolders. also remember that the backup folder is not modified if it already contains anything. and if it is not present, a new folder will be created )

~/git$ git clone --no-hardlinks ~/git/git_test1/   ~/git/bkp_repos/

The following uses relative paths :

~/git$ git clone --no-hardlinks git_test1/   bkp_repos2/

Comparing strings in C# with OR in an if statement

The code provided is correct, I don't see any reason why it wouldn't work. You could also try if (string1.Equals(string2)) as suggested.

To do if (something OR something else), use ||:

if (condition_1 || condition_2) { ... }

"Post Image data using POSTMAN"

Now you can hover the key input and select "file", which will give you a file selector in the value column:

enter image description here

selecting an entire row based on a variable excel vba

I solved the problem for me by addressing also the worksheet first:

ws.rows(x & ":" & y).Select

without the reference to the worksheet (ws) I got an error.

ActionLink htmlAttributes

Replace the desired hyphen with an underscore; it will automatically be rendered as a hyphen:

@Html.ActionLink("Edit", "edit", "markets",
    new { id = 1 },
    new {@class="ui-btn-right", data_icon="gear"})

becomes:

<form action="markets/Edit/1" class="ui-btn-right" data-icon="gear" .../>

Pass variables by reference in JavaScript

I like to solve the lack of by reference in JavaScript like this example shows.

The essence of this is that you don't try to create a by reference. You instead use the return functionality and make it able to return multiple values. So there isn't any need to insert your values in arrays or objects.

_x000D_
_x000D_
var x = "First";
var y = "Second";
var z = "Third";

log('Before call:',x,y,z);
with (myFunc(x, y, z)) {x = a; y = b; z = c;} // <-- Way to call it
log('After call :',x,y,z);


function myFunc(a, b, c) {
  a = "Changed first parameter";
  b = "Changed second parameter";
  c = "Changed third parameter";
  return {a:a, b:b, c:c}; // <-- Return multiple values
}

function log(txt,p1,p2,p3) {
  document.getElementById('msg').innerHTML += txt + '<br>' + p1 + '<br>' + p2 + '<br>' + p3 + '<br><br>'
}
_x000D_
<div id='msg'></div>
_x000D_
_x000D_
_x000D_

The ternary (conditional) operator in C

  • Some of the more obscure operators in C exist solely because they allow implementation of various function-like macros as a single expression that returns a result. I would say that this is the main purpose why the ?: and , operators are allowed to exist, even though their functionality is otherwise redundant.

    Lets say we wish to implement a function-like macro that returns the largest of two parameters. It would then be called as for example:

    int x = LARGEST(1,2);
    

    The only way to implement this as a function-like macro would be

    #define LARGEST(x,y) ((x) > (y) ? (x) : (y))
    

    It wouldn't be possible with an if ... else statement, since it does not return a result value. Note)

  • The other purpose of ?: is that it in some cases actually increases readability. Most often if...else is more readable, but not always. Take for example long, repetitive switch statements:

    switch(something)
    {
      case A: 
        if(x == A)
        {
          array[i] = x;
        }
        else
        {
          array[i] = y;
        }
        break;
    
      case B: 
        if(x == B)
        {
          array[i] = x;
        }
        else
        {
          array[i] = y;
        }
        break;
      ...
    }
    

    This can be replaced with the far more readable

    switch(something)
    {
      case A: array[i] = (x == A) ? x : y; break;
      case B: array[i] = (x == B) ? x : y; break;
      ...
    }
    
  • Please note that ?: does never result in faster code than if-else. That's some strange myth created by confused beginners. In case of optimized code, ?: gives identical performance as if-else in the vast majority of the cases.

    If anything, ?: can be slower than if-else, because it comes with mandatory implicit type promotions, even of the operand which is not going to be used. But ?: can never be faster than if-else.


Note) Now of course someone will argue and wonder why not use a function. Indeed if you can use a function, it is always preferable over a function-like macro. But sometimes you can't use functions. Suppose for example that x in the example above is declared at file scope. The initializer must then be a constant expression, so it cannot contain a function call. Other practical examples of where you have to use function-like macros involve type safe programming with _Generic or "X macros".

How to compile .c file with OpenSSL includes?

From the openssl.pc file

prefix=/usr
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
includedir=${prefix}/include

Name: OpenSSL
Description: Secure Sockets Layer and cryptography libraries and tools
Version: 0.9.8g
Requires:
Libs: -L${libdir} -lssl -lcrypto
Libs.private: -ldl -Wl,-Bsymbolic-functions -lz
Cflags: -I${includedir}

You can note the Include directory path and the Libs path from this. Now your prefix for the include files is /home/username/Programming . Hence your include file option should be -I//home/username/Programming.

(Yes i got it from the comments above)

This is just to remove logs regarding the headers. You may as well provide -L<Lib path> option for linking with the -lcrypto library.

How do you beta test an iphone app?

With iOS 8, Xcode 6, iTunes Connect and TestFlight you don't need UDIDs and Ad Hocs anymore. You will just need an Apple ID from your beta tester. Right now you can only beta test your app with 25 internal testers, but soon 1000 external testers will be available too. This blog post shows you how to setup a beta test with internal testers.

How to send email from MySQL 5.1

I would be very concerned about putting the load of sending e-mails on my database server (small though it may be). I might suggest one of these alternatives:

  1. Have application logic detect the need to send an e-mail and send it.
  2. Have a MySQL trigger populate a table that queues up the e-mails to be sent and have a process monitor that table and send the e-mails.

how to determine size of tablespace oracle 11g

One of the way is Using below sql queries

--Size of All Table Space

--1. Used Space
SELECT TABLESPACE_NAME,TO_CHAR(SUM(NVL(BYTES,0))/1024/1024/1024, '99,999,990.99') AS "USED SPACE(IN GB)" FROM USER_SEGMENTS GROUP BY TABLESPACE_NAME
--2. Free Space
SELECT TABLESPACE_NAME,TO_CHAR(SUM(NVL(BYTES,0))/1024/1024/1024, '99,999,990.99') AS "FREE SPACE(IN GB)" FROM   USER_FREE_SPACE GROUP BY TABLESPACE_NAME

--3. Both Free & Used
SELECT USED.TABLESPACE_NAME, USED.USED_BYTES AS "USED SPACE(IN GB)",  FREE.FREE_BYTES AS "FREE SPACE(IN GB)"
FROM
(SELECT TABLESPACE_NAME,TO_CHAR(SUM(NVL(BYTES,0))/1024/1024/1024, '99,999,990.99') AS USED_BYTES FROM USER_SEGMENTS GROUP BY TABLESPACE_NAME) USED
INNER JOIN
(SELECT TABLESPACE_NAME,TO_CHAR(SUM(NVL(BYTES,0))/1024/1024/1024, '99,999,990.99') AS FREE_BYTES FROM  USER_FREE_SPACE GROUP BY TABLESPACE_NAME) FREE
ON (USED.TABLESPACE_NAME = FREE.TABLESPACE_NAME);

Download File Using Javascript/jQuery

Excelent solution from Corbacho, I just adapted to get rid o the var

function downloadURL(url) {
    if( $('#idown').length ){
        $('#idown').attr('src',url);
    }else{
        $('<iframe>', { id:'idown', src:url }).hide().appendTo('body');
    }
}

How can I preview a merge in git?

Most answers here either require a clean working directory and multiple interactive steps (bad for scripting), or don't work for all cases, e.g. past merges which already bring some of the outstanding changes into your target branch, or cherry-picks doing the same.

To truly see what would change in the master branch if you merged develop into it, right now:

git merge-tree $(git merge-base master develop) master develop

As it's a plumbing command, it does not guess what you mean, you have to be explicit. It also doesn't colorize the output or use your pager, so the full command would be:

git merge-tree $(git merge-base master develop) master develop | colordiff | less -R

https://git.seveas.net/previewing-a-merge-result.html

(thanks to David Normington for the link)

P.S.:

If you would get merge conflicts, they will show up with the usual conflict markers in the output, e.g.:

$ git merge-tree $(git merge-base a b ) a b 
added in both
  our    100644 78981922613b2afb6025042ff6bd878ac1994e85 a
  their  100644 61780798228d17af2d34fce4cfbdf35556832472 a
@@ -1 +1,5 @@
+<<<<<<< .our
 a
+=======
+b
+>>>>>>> .their

User @dreftymac makes a good point: this makes it unsuitable for scripting, because you can't easily catch that from the status code. The conflict markers can be quite different depending on circumstance (deleted vs modified, etc), which makes it hard to grep, too. Beware.

Difference between "managed" and "unmanaged"

This is more general than .NET and Windows. Managed is an environment where you have automatic memory management, garbage collection, type safety, ... unmanaged is everything else. So for example .NET is a managed environment and C/C++ is unmanaged.

Mipmaps vs. drawable folders

The mipmap folders are for placing your app/launcher icons (which are shown on the homescreen) in only. Any other drawable assets you use should be placed in the relevant drawable folders as before.

According to this Google blogpost:

It’s best practice to place your app icons in mipmap- folders (not the drawable- folders) because they are used at resolutions different from the device’s current density.

When referencing the mipmap- folders ensure you are using the following reference:

android:icon="@mipmap/ic_launcher"

The reason they use a different density is that some launchers actually display the icons larger than they were intended. Because of this, they use the next size up.

Java properties UTF-8 encoding in Eclipse

Answer for "pre-Java-9" is below. As of Java 9, properties files are saved and loaded in UTF-8 by default, but falling back to ISO-8859-1 if an invalid UTF-8 byte sequence is detected. See the Java 9 release notes for details.


Properties files are ISO-8859-1 by definition - see the docs for the Properties class.

Spring has a replacement which can load with a specified encoding, using PropertiesFactoryBean.

EDIT: As Laurence noted in the comments, Java 1.6 introduced overloads for load and store which take a Reader/Writer. This means you can create a reader for the file with whatever encoding you want, and pass it to load. Unfortunately FileReader still doesn't let you specify the encoding in the constructor (aargh) so you'll be stuck with chaining FileInputStream and InputStreamReader together. However, it'll work.

For example, to read a file using UTF-8:

Properties properties = new Properties();
InputStream inputStream = new FileInputStream("path/to/file");
try {
    Reader reader = new InputStreamReader(inputStream, "UTF-8");
    try {
        properties.load(reader);
    } finally {
        reader.close();
    }
} finally {
   inputStream.close();
}

How to use the DropDownList's SelectedIndexChanged event

I think this is the culprit:

cmd = new SqlCommand(query, con);

DataTable dt = Select(query);

cmd.ExecuteNonQuery();

ddtype.DataSource = dt;

I don't know what that code is supposed to do, but it looks like you want to create an SqlDataReader for that, as explained here and all over the web if you search for "SqlCommand DropDownList DataSource":

cmd = new SqlCommand(query, con);
ddtype.DataSource = cmd.ExecuteReader();

Or you can create a DataTable as explained here:

cmd = new SqlCommand(query, con);

SqlDataAdapter listQueryAdapter = new SqlDataAdapter(cmd);
DataTable listTable = new DataTable();
listQueryAdapter.Fill(listTable);

ddtype.DataSource = listTable;

JS: Uncaught TypeError: object is not a function (onclick)

I was able to figure it out by following the answer in this thread: https://stackoverflow.com/a/8968495/1543447

Basically, I renamed all values, function names, and element names to different values so they wouldn't conflict - and it worked!

Extracting extension from filename in Python

a = ".bashrc"
b = "text.txt"
extension_a = a.split(".")
extension_b = b.split(".")
print(extension_a[-1])  # bashrc
print(extension_b[-1])  # txt

Nullable property to entity field, Entity Framework through Code First

The other option is to tell EF to allow the column to be null:

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
        modelBuilder.Entity<SomeObject>().Property(m => m.somefield).IsOptional();            
        base.OnModelCreating(modelBuilder);
}

This code should be in the object that inherits from DbContext.

Proper way to declare custom exceptions in modern Python?

see how exceptions work by default if one vs more attributes are used (tracebacks omitted):

>>> raise Exception('bad thing happened')
Exception: bad thing happened

>>> raise Exception('bad thing happened', 'code is broken')
Exception: ('bad thing happened', 'code is broken')

so you might want to have a sort of "exception template", working as an exception itself, in a compatible way:

>>> nastyerr = NastyError('bad thing happened')
>>> raise nastyerr
NastyError: bad thing happened

>>> raise nastyerr()
NastyError: bad thing happened

>>> raise nastyerr('code is broken')
NastyError: ('bad thing happened', 'code is broken')

this can be done easily with this subclass

class ExceptionTemplate(Exception):
    def __call__(self, *args):
        return self.__class__(*(self.args + args))
# ...
class NastyError(ExceptionTemplate): pass

and if you don't like that default tuple-like representation, just add __str__ method to the ExceptionTemplate class, like:

    # ...
    def __str__(self):
        return ': '.join(self.args)

and you'll have

>>> raise nastyerr('code is broken')
NastyError: bad thing happened: code is broken

How to access POST form fields

Use express-fileupload package:

var app = require('express')();
var http = require('http').Server(app);
const fileUpload = require('express-fileupload')

app.use(fileUpload());

app.post('/', function(req, res) {
  var email = req.body.email;
  res.send('<h1>Email :</h1> '+email);
});

http.listen(3000, function(){
  console.log('Running Port:3000');
});

Eclipse interface icons very small on high resolution screen in Windows 8.1

I had this problem when I changed my default Windows 10 language from Eng to Italian, with Eclipse being installed when default language was Eng. Reverting Windows language to Eng and rebooting solved the problem. I don’t know what’s happened, Windows rename some folders like C:\Users translating it in your default language (i.e. C:\Utenti) and maybe this is causing problems.

Amazon AWS Filezilla transfer permission denied

If you're using Ubuntu then use the following:

sudo chown -R ubuntu /var/www/html

sudo chmod -R 755 /var/www/html

Cannot resolve the collation conflict between "SQL_Latin1_General_CP1_CI_AS" and "Latin1_General_CI_AS" in the equal to operation

In the where criteria add collate SQL_Latin1_General_CP1_CI_AS

This works for me.

WHERE U.Fullname = @SearchTerm  collate SQL_Latin1_General_CP1_CI_AS

CGRectMake, CGPointMake, CGSizeMake, CGRectZero, CGPointZero is unavailable in Swift

If you want to use them as in swift 2, you can use these funcs:

For CGRectMake:

func CGRectMake(_ x: CGFloat, _ y: CGFloat, _ width: CGFloat, _ height: CGFloat) -> CGRect {
    return CGRect(x: x, y: y, width: width, height: height)
}

For CGPointMake:

func CGPointMake(_ x: CGFloat, _ y: CGFloat) -> CGPoint {
    return CGPoint(x: x, y: y)
}

For CGSizeMake:

func CGSizeMake(_ width: CGFloat, _ height: CGFloat) -> CGSize {
    return CGSize(width: width, height: height)
}

Just put them outside any class and it should work. (Works for me at least)

MySQL create stored procedure syntax with delimiter

Here is my code to create procedure in MySQL :

DELIMITER $$
CREATE DEFINER=`root`@`localhost` PROCEDURE `procedureName`(IN comId int)
BEGIN
select * from tableName 
         (add joins OR sub query as per your requirement)
         Where (where condition here)
END $$
DELIMITER ;

To call this procedure use this query :

call procedureName(); // without parameter
call procedureName(id,pid); // with parameter

Detail :

1) DEFINER : root is the user name and change it as per your username of mysql localhost is the host you can change it with ip address of the server if you are execute this query on hosting server.

Read here for more detail

Bad File Descriptor with Linux Socket write() Bad File Descriptor C

In general, when "Bad File Descriptor" is encountered, it means that the socket file descriptor you passed into the API is not valid, which has multiple possible reasons:

  1. The fd is already closed somewhere.
  2. The fd has a wrong value, which is inconsistent with the value obtained from socket() api

How do I get the path and name of the file that is currently executing?

I have always just used the os feature of Current Working Directory, or CWD. This is part of the standard library, and is very easy to implement. Here is an example:

    import os
    base_directory = os.getcwd()

Why am I getting error for apple-touch-icon-precomposed.png

If you ended here googling, this is a simple configuration to prevent this error full the web server logs:

Apache virtualhost

Redirect 404 /apple-touch-icon-precomposed.png
<Location /apple-touch-icon-precomposed.png>
    ErrorDocument 404 "apple-touch-icon-precomposed does not exist"
</Location>

Nginx server block:

location =/apple-touch-icon-precomposed.png {
        log_not_found off;
        access_log off;
}

PS: Is possible you want to add apple-touch-icon.png and favicon.ico too.

jQuery Mobile: Stick footer to bottom of page

You can add this in your css file:

[data-role=page]{height: 100% !important; position:relative !important;}
[data-role=footer]{bottom:0; position:absolute !important; top: auto !important; width:100%;}  

So the page data-role now have 100% height, and footer is in absolute position.

Also Yappo have wrote an excellent plugin that you can find here: jQuery Mobile in a iScroll plugin http://yappo.github.com/projects/jquery.mobile.iscroll/livedemo.html

hope you found the answer!

An answer update

You can now use the data-position="fixed" attribute to keep your footer element on the bottom.
Docs and demos: http://view.jquerymobile.com/master/demos/toolbar-fixed/

Color Tint UIButton Image

As of iOS 7, there is a new method on UIImage to specify the rendering mode. Using the rendering mode UIImageRenderingModeAlwaysTemplate will allow the image color to be controlled by the button's tint color.

Objective-C

UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
UIImage *image = [[UIImage imageNamed:@"image_name"] imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
[button setImage:image forState:UIControlStateNormal]; 
button.tintColor = [UIColor redColor];

Swift

let button = UIButton(type: .custom)
let image = UIImage(named: "image_name")?.withRenderingMode(.alwaysTemplate)
button.setImage(image, for: .normal)
button.tintColor = UIColor.red

List of all users that can connect via SSH

Read man sshd_config for more details, but you can use the AllowUsers directive in /etc/ssh/sshd_config to limit the set of users who can login.

e.g.

AllowUsers boris

would mean that only the boris user could login via ssh.

sed edit file in place

Very good examples. I had the challenge to edit in place many files and the -i option seems to be the only reasonable solution using it within the find command. Here the script to add "version:" in front of the first line of each file:

find . -name pkg.json -print -exec sed -i '.bak' '1 s/^/version /' {} \;

Jenkins - Configure Jenkins to poll changes in SCM

I believe best practice these days is H/5 * * * *, which means every 5 minutes with a hashing factor to avoid all jobs starting at EXACTLY the same time.

Http Post request with content type application/x-www-form-urlencoded not working in Spring

The solution can be found here https://github.com/spring-projects/spring-framework/issues/22734

you can create two separate post request mappings. For example.

@PostMapping(path = "/test", consumes = "application/json")
public String test(@RequestBody User user) {
  return user.toString();
}

@PostMapping(path = "/test", consumes = "application/x-www-form-urlencoded")
public String test(User user) {
  return user.toString();
}

How to add multiple jar files in classpath in linux

You use the -classpath argument. You can use either a relative or absolute path. What that means is you can use a path relative to your current directory, OR you can use an absolute path that starts at the root /.

Example:

bash$ java -classpath path/to/jar/file MyMainClass

In this example the main function is located in MyMainClass and would be included somewhere in the jar file.

For compiling you need to use javac

Example:

bash$ javac -classpath path/to/jar/file MyMainClass.java

You can also specify the classpath via the environment variable, follow this example:

bash$ export CLASSPATH="path/to/jar/file:path/tojar/file2"
bash$ javac MyMainClass.java

For any normally complex java project you should look for the ant script named build.xml

make script execution to unlimited

As @Peter Cullen answer mention, your script will meet browser timeout first. So its good idea to provide some log output, then flush(), but connection have buffer and you'll not see anything unless much output provided. Here are code snippet what helps provide reliable log:

set_time_limit(0);
...
print "log message";
print "<!--"; print str_repeat (' ', 4000); print "-->"; flush();
print "log message";
print "<!--"; print str_repeat (' ', 4000); print "-->"; flush();

How to create my json string by using C#?

The json is kind of odd, it's like the students are properties of the "GetQuestion" object, it should be easy to be a List.....

About the libraries you could use are.

And there could be many more, but that are what I've used

About the json I don't now maybe something like this

public class GetQuestions
{
    public List<Student> Questions { get; set; }
}

public class Student
{
    public string Code { get; set; }
    public string Questions { get; set; }
}

void Main()
{
    var gq = new GetQuestions
    {
        Questions = new List<Student>
        {
            new Student {Code = "s1", Questions = "Q1,Q2"},
            new Student {Code = "s2", Questions = "Q1,Q2,Q3"},
            new Student {Code = "s3", Questions = "Q1,Q2,Q4"},
            new Student {Code = "s4", Questions = "Q1,Q2,Q5"},
        }
    };

    //Using Newtonsoft.json. Dump is an extension method of [Linqpad][4]
    JsonConvert.SerializeObject(gq).Dump();
}

Linqpad

and the result is this

{
     "Questions":[
        {"Code":"s1","Questions":"Q1,Q2"},
        {"Code":"s2","Questions":"Q1,Q2,Q3"},
        {"Code":"s3","Questions":"Q1,Q2,Q4"},
        {"Code":"s4","Questions":"Q1,Q2,Q5"}
      ]
 }

Yes I know the json is different, but the json that you want with dictionary.

void Main()
{
    var f = new Foo
    {
        GetQuestions = new Dictionary<string, string>
                {
                    {"s1", "Q1,Q2"},
                    {"s2", "Q1,Q2,Q3"},
                    {"s3", "Q1,Q2,Q4"},
                    {"s4", "Q1,Q2,Q4,Q6"},
                }
    };

    JsonConvert.SerializeObject(f).Dump();
}

class Foo
{
    public Dictionary<string, string> GetQuestions { get; set; }
}

And with Dictionary is as you want it.....

{
      "GetQuestions":
       {
              "s1":"Q1,Q2",
              "s2":"Q1,Q2,Q3",
              "s3":"Q1,Q2,Q4",
              "s4":"Q1,Q2,Q4,Q6"
       }
 }

Load HTML page dynamically into div with jQuery

JQuery load works, but it will strip out javascript and other elements from the source page. This makes sense because you might not want to introduce bad script on your page. I think this is a limitation and since you are doing a whole page and not just a div on the source page, you might not want to use it. (I am not sure about css, but I think it would also get stripped)

In this example, if you put a tag around the body of your source page, it will grab anything in between the tags and won't strip anything out. I wrap my source page with and .

This solution will grab everything between the above delimiters. I feel it is a much more robust solution than a simple load.

  var content = $('.contentDiv');
    content.load(urlAddress, function (response, status, xhr) {
        var fullPageTextAsString = response;
        var pageTextBetweenDelimiters = fullPageTextAsString.substring(fullPageTextAsString.indexOf("<jqueryloadmarkerstart />"), fullPageTextAsString.indexOf("<jqueryloadmarkerend />"));
        content.html(pageTextBetweenDelimiters);
    });

Java. Implicit super constructor Employee() is undefined. Must explicitly invoke another constructor

As others have already mentioned you are required to provide a default constructor public Employee(){} in your Employee class.

What happens is that the compiler automatically provides a no-argument, default constructor for any class without constructors. If your class has no explicit superclass, then it has an implicit superclass of Object, which does have a no-argument constructor. In this case you are declaring a constructor in your class Employee therefore you must provide also the no-argument constructor.

Having said that Employee class should look like this:

Your class Employee

import java.util.Date;

public class Employee
{
      private String name, number;
      private Date date;

      public Employee(){} // No-argument Constructor

      public Employee(String name, String number, Date date)
      {
            setName(name);
            setNumber(number);
            setDate(date);
      }

      public void setName(String n)
      {
            name = n;
      }
      public void setNumber(String n)
      {
            number = n;
            // you can check the format here for correctness
      }
      public void setDate(Date d)
      {
            date = d;
      }

      public String getName()
      {
            return name;
      }
      public String getNumber()
      {
            return number;
      }
      public Date getDate()
      {
            return date;
      }
}

Here is the Java Oracle tutorial - Providing Constructors for Your Classes chapter. Go through it and you will have a clearer idea of what is going on.

Fatal error: Call to a member function query() on null

put this line in parent construct : $this->load->database();

function  __construct() {
    parent::__construct();
    $this->load->library('lib_name');
    $model=array('model_name');
    $this->load->model($model);
    $this->load->database();
}

this way.. it should work..

Removing "http://" from a string

Try this out:

$url = 'http://techcrunch.com/startups/'; $url = str_replace(array('http://', 'https://'), '', $url); 

EDIT:

Or, a simple way to always remove the protocol:

$url = 'https://www.google.com/'; $url = preg_replace('@^.+?\:\/\/@', '', $url); 

CryptographicException 'Keyset does not exist', but only through WCF

This is most likely because the IIS user doesn't have access to the private key for your certificate. You can set this by following these steps...

  1. Start ? Run ? MMC
  2. File ? Add/Remove Snapin
  3. Add the Certificates Snap In
  4. Select Computer Account, then hit next
  5. Select Local Computer (the default), then click Finish
  6. On the left panel from Console Root, navigate to Certificates (Local Computer) ? Personal ? Certificates
  7. Your certificate will most likely be here.
  8. Right click on your certificate ? All Tasks ? Manage Private Keys
  9. Set your private key settings here.

Difference between numpy.array shape (R, 1) and (R,)

The data structure of shape (n,) is called a rank 1 array. It doesn't behave consistently as a row vector or a column vector which makes some of its operations and effects non intuitive. If you take the transpose of this (n,) data structure, it'll look exactly same and the dot product will give you a number and not a matrix. The vectors of shape (n,1) or (1,n) row or column vectors are much more intuitive and consistent.

Commenting out a set of lines in a shell script

What if you just wrap your code into function?

So this:

cd ~/documents
mkdir test
echo "useless script" > about.txt

Becomes this:

CommentedOutBlock() {
  cd ~/documents
  mkdir test
  echo "useless script" > about.txt
}

An error occurred while collecting items to be installed (Access is denied)

On Windows 7, the Program Files directory is protected so apps can't automatically write there. The simplest solution I've heard is just to install Eclipse into a user-writable location instead. For example, C:\Java\Eclipse

You should be able to just move your entire eclipse directory, there's no registry entries or anything else that ties Eclipse to the place where you extracted it.

[Edit] Have you checked that the directory it is complaining about i actually writable? Other than that, I really don't have any ideas. I haven't worked on Windows in several years and never with Win7. My only other suggestion is to just download the latest Eclipse, install it to a new location (do NOT intall it over top of your existing Eclipse), and point it to your existing workspace.

How do servlets work? Instantiation, sessions, shared variables and multithreading

ServletContext

When the servlet container (like Apache Tomcat) starts up, it will deploy and load all its web applications. When a web application is loaded, the servlet container creates the ServletContext once and keeps it in the server's memory. The web app's web.xml and all of included web-fragment.xml files is parsed, and each <servlet>, <filter> and <listener> found (or each class annotated with @WebServlet, @WebFilter and @WebListener respectively) is instantiated once and kept in the server's memory as well. For each instantiated filter, its init() method is invoked with a new FilterConfig.

When a Servlet has a <servlet><load-on-startup> or @WebServlet(loadOnStartup) value greater than 0, then its init() method is also invoked during startup with a new ServletConfig. Those servlets are initialized in the same order specified by that value (1 is 1st, 2 is 2nd, etc). If the same value is specified for more than one servlet, then each of those servlets is loaded in the same order as they appear in the web.xml, web-fragment.xml, or @WebServlet classloading. In the event the "load-on-startup" value is absent, the init() method will be invoked whenever the HTTP request hits that servlet for the very first time.

When the servlet container is finished with all of the above described initialization steps, then the ServletContextListener#contextInitialized() will be invoked.

When the servlet container shuts down, it unloads all web applications, invokes the destroy() method of all its initialized servlets and filters, and all ServletContext, Servlet, Filter and Listener instances are trashed. Finally the ServletContextListener#contextDestroyed() will be invoked.

HttpServletRequest and HttpServletResponse

The servlet container is attached to a web server that listens for HTTP requests on a certain port number (port 8080 is usually used during development and port 80 in production). When a client (e.g. user with a web browser, or programmatically using URLConnection) sends an HTTP request, the servlet container creates new HttpServletRequest and HttpServletResponse objects and passes them through any defined Filter in the chain and, eventually, the Servlet instance.

In the case of filters, the doFilter() method is invoked. When the servlet container's code calls chain.doFilter(request, response), the request and response continue on to the next filter, or hit the servlet if there are no remaining filters.

In the case of servlets, the service() method is invoked. By default, this method determines which one of the doXxx() methods to invoke based off of request.getMethod(). If the determined method is absent from the servlet, then an HTTP 405 error is returned in the response.

The request object provides access to all of the information about the HTTP request, such as its URL, headers, query string and body. The response object provides the ability to control and send the HTTP response the way you want by, for instance, allowing you to set the headers and the body (usually with generated HTML content from a JSP file). When the HTTP response is committed and finished, both the request and response objects are recycled and made available for reuse.

HttpSession

When a client visits the webapp for the first time and/or the HttpSession is obtained for the first time via request.getSession(), the servlet container creates a new HttpSession object, generates a long and unique ID (which you can get by session.getId()), and stores it in the server's memory. The servlet container also sets a Cookie in the Set-Cookie header of the HTTP response with JSESSIONID as its name and the unique session ID as its value.

As per the HTTP cookie specification (a contract any decent web browser and web server must adhere to), the client (the web browser) is required to send this cookie back in subsequent requests in the Cookie header for as long as the cookie is valid (i.e. the unique ID must refer to an unexpired session and the domain and path are correct). Using your browser's built-in HTTP traffic monitor, you can verify that the cookie is valid (press F12 in Chrome / Firefox 23+ / IE9+, and check the Net/Network tab). The servlet container will check the Cookie header of every incoming HTTP request for the presence of the cookie with the name JSESSIONID and use its value (the session ID) to get the associated HttpSession from server's memory.

The HttpSession stays alive until it has been idle (i.e. not used in a request) for more than the timeout value specified in <session-timeout>, a setting in web.xml. The timeout value defaults to 30 minutes. So, when the client doesn't visit the web app for longer than the time specified, the servlet container trashes the session. Every subsequent request, even with the cookie specified, will not have access to the same session anymore; the servlet container will create a new session.

On the client side, the session cookie stays alive for as long as the browser instance is running. So, if the client closes the browser instance (all tabs/windows), then the session is trashed on the client's side. In a new browser instance, the cookie associated with the session wouldn't exist, so it would no longer be sent. This causes an entirely new HttpSession to be created, with an entirely new session cookie being used.

In a nutshell

  • The ServletContext lives for as long as the web app lives. It is shared among all requests in all sessions.
  • The HttpSession lives for as long as the client is interacting with the web app with the same browser instance, and the session hasn't timed out at the server side. It is shared among all requests in the same session.
  • The HttpServletRequest and HttpServletResponse live from the time the servlet receives an HTTP request from the client, until the complete response (the web page) has arrived. It is not shared elsewhere.
  • All Servlet, Filter and Listener instances live as long as the web app lives. They are shared among all requests in all sessions.
  • Any attribute that is defined in ServletContext, HttpServletRequest and HttpSession will live as long as the object in question lives. The object itself represents the "scope" in bean management frameworks such as JSF, CDI, Spring, etc. Those frameworks store their scoped beans as an attribute of its closest matching scope.

Thread Safety

That said, your major concern is possibly thread safety. You should now know that servlets and filters are shared among all requests. That's the nice thing about Java, it's multithreaded and different threads (read: HTTP requests) can make use of the same instance. It would otherwise be too expensive to recreate, init() and destroy() them for every single request.

You should also realize that you should never assign any request or session scoped data as an instance variable of a servlet or filter. It will be shared among all other requests in other sessions. That's not thread-safe! The below example illustrates this:

public class ExampleServlet extends HttpServlet {

    private Object thisIsNOTThreadSafe;

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Object thisIsThreadSafe;

        thisIsNOTThreadSafe = request.getParameter("foo"); // BAD!! Shared among all requests!
        thisIsThreadSafe = request.getParameter("foo"); // OK, this is thread safe.
    } 
}

See also:

How to convert a boolean array to an int array

The 1*y method works in Numpy too:

>>> import numpy as np
>>> x = np.array([4, 3, 2, 1])
>>> y = 2 >= x
>>> y
array([False, False,  True,  True], dtype=bool)
>>> 1*y                      # Method 1
array([0, 0, 1, 1])
>>> y.astype(int)            # Method 2
array([0, 0, 1, 1]) 

If you are asking for a way to convert Python lists from Boolean to int, you can use map to do it:

>>> testList = [False, False,  True,  True]
>>> map(lambda x: 1 if x else 0, testList)
[0, 0, 1, 1]
>>> map(int, testList)
[0, 0, 1, 1]

Or using list comprehensions:

>>> testList
[False, False, True, True]
>>> [int(elem) for elem in testList]
[0, 0, 1, 1]

How to set a hidden value in Razor

There is a Hidden helper alongside HiddenFor which lets you set the value.

@Html.Hidden("RequiredProperty", "default")

EDIT Based on the edit you've made to the question, you could do this, but I believe you're moving into territory where it will be cheaper and more effective, in the long run, to fight for making the code change. As has been said, even by yourself, the controller or view model should be setting the default.

This code:

<ul>
@{
        var stacks = new System.Diagnostics.StackTrace().GetFrames();
        foreach (var frame in stacks)
        {
            <li>@frame.GetMethod().Name - @frame.GetMethod().DeclaringType</li>
        }
}
</ul>

Will give output like this:

Execute - ASP._Page_Views_ViewDirectoryX__SubView_cshtml
ExecutePageHierarchy - System.Web.WebPages.WebPageBase
ExecutePageHierarchy - System.Web.Mvc.WebViewPage
ExecutePageHierarchy - System.Web.WebPages.WebPageBase
RenderView - System.Web.Mvc.RazorView
Render - System.Web.Mvc.BuildManagerCompiledView
RenderPartialInternal - System.Web.Mvc.HtmlHelper
RenderPartial - System.Web.Mvc.Html.RenderPartialExtensions
Execute - ASP._Page_Views_ViewDirectoryY__MainView_cshtml

So assuming the MVC framework will always go through the same stack, you can grab var frame = stacks[8]; and use the declaring type to determine who your parent view is, and then use that determination to set (or not) the default value. You could also walk the stack instead of directly grabbing [8] which would be safer but even less efficient.

Turn Pandas Multi-Index into column

The reset_index() is a pandas DataFrame method that will transfer index values into the DataFrame as columns. The default setting for the parameter is drop=False (which will keep the index values as columns).

All you have to do add .reset_index(inplace=True) after the name of the DataFrame:

df.reset_index(inplace=True)  

SQL MAX of multiple columns?

You could create a function where you pass the dates and then add the function to the select statement like below. select Number, dbo.fxMost_Recent_Date(Date1,Date2,Date3), Cost

create FUNCTION  fxMost_Recent_Date 

( @Date1 smalldatetime, @Date2 smalldatetime, @Date3 smalldatetime ) RETURNS smalldatetime AS BEGIN DECLARE @Result smalldatetime

declare @MostRecent smalldatetime

set @MostRecent='1/1/1900'

if @Date1>@MostRecent begin set @MostRecent=@Date1 end
if @Date2>@MostRecent begin set @MostRecent=@Date2 end
if @Date3>@MostRecent begin set @MostRecent=@Date3 end
RETURN @MostRecent

END

PySpark: withColumn() with two conditions and three outcomes

The withColumn function in pyspark enables you to make a new variable with conditions, add in the when and otherwise functions and you have a properly working if then else structure. For all of this you would need to import the sparksql functions, as you will see that the following bit of code will not work without the col() function. In the first bit, we declare a new column -'new column', and then give the condition enclosed in when function (i.e. fruit1==fruit2) then give 1 if the condition is true, if untrue the control goes to the otherwise which then takes care of the second condition (fruit1 or fruit2 is Null) with the isNull() function and if true 3 is returned and if false, the otherwise is checked again giving 0 as the answer.

from pyspark.sql import functions as F
df=df.withColumn('new_column', 
    F.when(F.col('fruit1')==F.col('fruit2'), 1)
    .otherwise(F.when((F.col('fruit1').isNull()) | (F.col('fruit2').isNull()), 3))
    .otherwise(0))

How to play YouTube video in my Android application?

Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.youtube.com/watchv=cxLG2wtE7TM"));
startActivity(intent);

How to create a file in Ruby

data = 'data you want inside the file'.

You can use File.write('name of file here', data)

CSS Selector for <input type="?"

Yes. IE7+ supports attribute selectors:

input[type=radio]
input[type^=ra]
input[type*=d]
input[type$=io]

Element input with attribute type which contains a value that is equal to, begins with, contains or ends with a certain value.

Other safe (IE7+) selectors are:

  • Parent > child that has: p > span { font-weight: bold; }
  • Preceded by ~ element which is: span ~ span { color: blue; }

Which for <p><span/><span/></p> would effectively give you:

<p>
    <span style="font-weight: bold;">
    <span style="font-weight: bold; color: blue;">
</p>

Further reading: Browser CSS compatibility on quirksmode.com

I'm surprised that everyone else thinks it can't be done. CSS attribute selectors have been here for some time already. I guess it's time we clean up our .css files.

How to get the date and time values in a C program?

Timespec has day of year built in.

http://pubs.opengroup.org/onlinepubs/7908799/xsh/time.h.html

#include <time.h>
int get_day_of_year(){
    time_t t = time(NULL);
    struct tm tm = *localtime(&t);
    return tm.tm_yday;
}`

Arithmetic overflow error converting numeric to data type numeric

I feel I need to clarify one very important thing, for others (like my co-worker) who came across this thread and got the wrong information.

The answer given ("Try decimal(9,2) or decimal(10,2) or whatever.") is correct, but the reason ("increase the number of digits before the decimal") is wrong.

decimal(p,s) and numeric(p,s) both specify a Precision and a Scale. The "precision" is not the number of digits to the left of the decimal, but instead is the total precision of the number.

For example: decimal(2,1) covers 0.0 to 9.9, because the precision is 2 digits (00 to 99) and the scale is 1. decimal(4,1) covers 000.0 to 999.9 decimal(4,2) covers 00.00 to 99.99 decimal(4,3) covers 0.000 to 9.999

How can I perform static code analysis in PHP?

PHP PMD (Programming Mistake Detector) and PHP CPD (Copy/Paste Detector) as the former part of PHPUnit.

How to create a template function within a class? (C++)

The easiest way is to put the declaration and definition in the same file, but it may cause over-sized excutable file. E.g.

class Foo
{
public:
template <typename T> void some_method(T t) {//...}
}

Also, it is possible to put template definition in the separate files, i.e. to put them in .cpp and .h files. All you need to do is to explicitly include the template instantiation to the .cpp files. E.g.

// .h file
class Foo
{
public:
template <typename T> void some_method(T t);
}

// .cpp file
//...
template <typename T> void Foo::some_method(T t) 
{//...}
//...

template void Foo::some_method<int>(int);
template void Foo::some_method<double>(double);

show dbs gives "Not Authorized to execute command" error

Create a user like this:

db.createUser(
      {
        user: "myUserAdmin",
        pwd: "abc123",
        roles: [ { role: "userAdminAnyDatabase", db: "admin" } ]
      }
    )

Then connect it following this:

mongo --port 27017 -u "myUserAdmin" -p "abc123" --authenticationDatabase "admin"

Check the manual :

https://docs.mongodb.org/manual/tutorial/enable-authentication/

Which browsers support <script async="async" />?

Just had a look at the DOM (document.scripts[1].attributes) of this page that uses google analytics. I can tell you that google is using async="".

[type="text/javascript", async="", src="http://www.google-analytics.com/ga.js"]

Session 'app' error while installing APK

Revoke USB debugging authorizations and then disable USB debugging on your mobile. Re-enable USB debugging, then connect to the USB port. It will ask USB debugging permission for the specific computer. Select "Always allow from this computer", then press OK. This worked for me.

How to replace an entire line in a text file by line number

Not the greatest, but this should work:

sed -i 'Ns/.*/replacement-line/' file.txt

where N should be replaced by your target line number. This replaces the line in the original file. To save the changed text in a different file, drop the -i option:

sed 'Ns/.*/replacement-line/' file.txt > new_file.txt

Test a weekly cron job

I'm using Webmin because its a productivity gem for someone who finds command line administration a bit daunting and impenetrable.

There is a "Save and Run Now" button in the "System > Scheduled Cron Jobs > Edit Cron Job" web interface.

It displays the output of the command and is exactly what I needed.

Run an OLS regression with Pandas Data Frame

I think you can almost do exactly what you thought would be ideal, using the statsmodels package which was one of pandas' optional dependencies before pandas' version 0.20.0 (it was used for a few things in pandas.stats.)

>>> import pandas as pd
>>> import statsmodels.formula.api as sm
>>> df = pd.DataFrame({"A": [10,20,30,40,50], "B": [20, 30, 10, 40, 50], "C": [32, 234, 23, 23, 42523]})
>>> result = sm.ols(formula="A ~ B + C", data=df).fit()
>>> print(result.params)
Intercept    14.952480
B             0.401182
C             0.000352
dtype: float64
>>> print(result.summary())
                            OLS Regression Results                            
==============================================================================
Dep. Variable:                      A   R-squared:                       0.579
Model:                            OLS   Adj. R-squared:                  0.158
Method:                 Least Squares   F-statistic:                     1.375
Date:                Thu, 14 Nov 2013   Prob (F-statistic):              0.421
Time:                        20:04:30   Log-Likelihood:                -18.178
No. Observations:                   5   AIC:                             42.36
Df Residuals:                       2   BIC:                             41.19
Df Model:                           2                                         
==============================================================================
                 coef    std err          t      P>|t|      [95.0% Conf. Int.]
------------------------------------------------------------------------------
Intercept     14.9525     17.764      0.842      0.489       -61.481    91.386
B              0.4012      0.650      0.617      0.600        -2.394     3.197
C              0.0004      0.001      0.650      0.583        -0.002     0.003
==============================================================================
Omnibus:                          nan   Durbin-Watson:                   1.061
Prob(Omnibus):                    nan   Jarque-Bera (JB):                0.498
Skew:                          -0.123   Prob(JB):                        0.780
Kurtosis:                       1.474   Cond. No.                     5.21e+04
==============================================================================

Warnings:
[1] The condition number is large, 5.21e+04. This might indicate that there are
strong multicollinearity or other numerical problems.

jQuery & CSS - Remove/Add display:none

For some reason, toggle didn't work for me, and I received the error uncaught type error toggle is not a function when inspecting the element in browser. So I used the following code and it started working for me.

$(".trigger").click(function () {
    $('.news').attr('style', 'display:none');
})

Used jquery script file jquery-2.1.3.min.js.

How to trim a file extension from a String in JavaScript?

Another one liner - we presume our file is a jpg picture >> ex: var yourStr = 'test.jpg';

    yourStr = yourStr.slice(0, -4); // 'test'

Correct way to remove plugin from Eclipse

I would like to propose my solution,that worked for me.

It's reverting Eclipse and its plugins versions, to the version just before the plugin was installed.

How can I get the current user's username in Bash?

All,

From what I'm seeing here all answers are wrong, especially if you entered the sudo mode, with all returning 'root' instead of the logged in user. The answer is in using 'who' and finding eh 'tty1' user and extracting that. Thw "w" command works the same and var=$SUDO_USER gets the real logged in user.

Cheers!

TBNK

Has anyone ever got a remote JMX JConsole to work?

I'm using boot2docker to run docker containers with Tomcat inside and I've got the same problem, the solution was to:

  • Add -Djava.rmi.server.hostname=192.168.59.103
  • Use the same JMX port in host and docker container, for instance: docker run ... -p 9999:9999 .... Using different ports does not work.

Full screen background image in an activity

If you have bg.png as your background image then simply:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/bg"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:text="@string/hello_world"/>
</RelativeLayout>

How to search in commit messages using command line?

git log --grep=<pattern>
    Limit the commits output to ones with log message that matches the 
    specified pattern (regular expression).

--git help log

How can I embed a YouTube video on GitHub wiki pages?

If you like HTML tags more than markdown + center alignment:

_x000D_
_x000D_
<div align="center">_x000D_
  <a href="https://www.youtube.com/watch?v=YOUTUBE_VIDEO_ID_HERE"><img src="https://img.youtube.com/vi/YOUTUBE_VIDEO_ID_HERE/0.jpg" alt="IMAGE ALT TEXT"></a>_x000D_
</div>
_x000D_
_x000D_
_x000D_

What is the significance of #pragma marks? Why do we need #pragma marks?

#pragma mark - NSSecureCoding

The main purpose of "pragma" is for developer reference.enter image description here

You can easily find a method/Function in a vast thousands of coding lines.

Xcode 11+:

Marker Line in Top

// MARK: - Properties

Marker Line in Top and Bottom

// MARK: - Properties - 

Marker Line only in bottom

// MARK: Properties -

Javascript to export html table to Excel

If you add:

<meta http-equiv="content-type" content="text/plain; charset=UTF-8"/>

in the head of the document it will start working as expected:

<script type="text/javascript">
var tableToExcel = (function() {
  var uri = 'data:application/vnd.ms-excel;base64,'
    , template = '<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns="http://www.w3.org/TR/REC-html40"><head><!--[if gte mso 9]><xml><x:ExcelWorkbook><x:ExcelWorksheets><x:ExcelWorksheet><x:Name>{worksheet}</x:Name><x:WorksheetOptions><x:DisplayGridlines/></x:WorksheetOptions></x:ExcelWorksheet></x:ExcelWorksheets></x:ExcelWorkbook></xml><![endif]--><meta http-equiv="content-type" content="text/plain; charset=UTF-8"/></head><body><table>{table}</table></body></html>'
    , base64 = function(s) { return window.btoa(unescape(encodeURIComponent(s))) }
    , format = function(s, c) { return s.replace(/{(\w+)}/g, function(m, p) { return c[p]; }) }
  return function(table, name) {
    if (!table.nodeType) table = document.getElementById(table)
    var ctx = {worksheet: name || 'Worksheet', table: table.innerHTML}
    window.location.href = uri + base64(format(template, ctx))
  }
})()
</script>

Updated Fiddle Here.

How to declare an array of strings in C++?

You can concisely initialize a vector<string> from a statically-created char* array:

char* strarray[] = {"hey", "sup", "dogg"};
vector<string> strvector(strarray, strarray + 3);

This copies all the strings, by the way, so you use twice the memory. You can use Will Dean's suggestion to replace the magic number 3 here with arraysize(str_array) -- although I remember there being some special case in which that particular version of arraysize might do Something Bad (sorry I can't remember the details immediately). But it very often works correctly.

Also, if you're really gung-ho about the one line thingy, you can define a variadic macro so that a single line such as DEFINE_STR_VEC(strvector, "hi", "there", "everyone"); works.

How to get a unique computer identifier in Java (like disk ID or motherboard ID)?

The usage of MAC id is most easier way if the task is about logging the unique id a system.

the change of mac id is though possible, even the change of other ids of a system are also possible is that respective device is replaced.

so, unless what for a unique id is required is not known, we may not be able to find an appropriate solution.

However, the below link is helpful extracting mac addresses. http://www.stratos.me/2008/07/find-mac-address-using-java/

What does the "assert" keyword do?

If you launch your program with -enableassertions (or -ea for short) then this statement

assert cond;

is equivalent to

if (!cond)
    throw new AssertionError();

If you launch your program without this option, the assert statement will have no effect.

For example, assert d >= 0 && d <= s.length();, as posted in your question, is equivalent to

if (!(d >= 0 && d <= s.length()))
    throw new AssertionError();

(If you launched with -enableassertions that is.)


Formally, the Java Language Specification: 14.10. The assert Statement says the following:

14.10. The assert Statement
An assertion is an assert statement containing a boolean expression. An assertion is either enabled or disabled. If the assertion is enabled, execution of the assertion causes evaluation of the boolean expression and an error is reported if the expression evaluates to false. If the assertion is disabled, execution of the assertion has no effect whatsoever.

Where "enabled or disabled" is controlled with the -ea switch and "An error is reported" means that an AssertionError is thrown.


And finally, a lesser known feature of assert:

You can append : "Error message" like this:

assert d != null : "d is null";

to specify what the error message of the thrown AssertionError should be.


This post has been rewritten as an article here.