What does "Failure [INSTALL_FAILED_OLDER_SDK]" mean in Android Studio?

This error

Failure [INSTALL_FAILED_OLDER_SDK]

Means that you're trying to install an app that has a higher minSdkVersion specified in its manifest than the device's API level. Change that number to 8 and it should work. I'm not sure about the other error, but it may be related to this one.

JSONDecodeError: Expecting value: line 1 column 1 (char 0)

In my case it is because the server is giving http error occasionally. So basically once in a while my script gets the response like this rahter than the expected response:

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html>
<head><title>502 Bad Gateway</title></head>
<body bgcolor="white">
<h1>502 Bad Gateway</h1>
<p>The proxy server received an invalid response from an upstream server.<hr/>Powered by Tengine</body>
</html>

Clearly this is not in json format and trying to call .json() will yield JSONDecodeError: Expecting value: line 1 column 1 (char 0)

You can print the exact response that causes this error to better debug. For example if you are using requests and then simply print the .text field (before you call .json()) would do.

Send POST data on redirect with JavaScript/jQuery?

The answers here can be confusing so i will give you a sample code that i am working with.

To start with note that there is no POST parameter to java script windows.location function that you are referring to.

So you have to...

Dynamically make a form with a POST parameter.
Dynamically put a textbox or textboxes with your desired values to post
Invoke the submit form you dynamically created.

And for the example.

     //---------- make sure to link to your jQuery library ----//

<script type="text/javascript" >

    var form = $(document.createElement('form'));
    $(form).attr("action", "test2.php");
    $(form).attr("method", "POST");
    $(form).css("display", "none");

    var input_employee_name = $("<input>")
    .attr("type", "text")
    .attr("name", "employee_name")
    .val("Peter" );
    $(form).append($(input_employee_name));


    var input_salary = $("<input>")
    .attr("type", "text")
    .attr("name", "salary")
    .val("1000" );
    $(form).append($(input_salary));

    form.appendTo( document.body );
    $(form).submit();

</script>

If all is done well, you shall be redirected to test2.php and you can use POST to read passed values of employee_name and salary; that will be Peter and 1000 respectively.

On test2.php you can get your values thus.

$employee_name = $_POST['employee_name'];
$salary = $_POST['salary'];

Needless to say , make sure you sanitize your passed values.

Unable to launch the IIS Express Web server

Jason's Shavers series of articles here http://jasonrshaver.com/?tag=/Client+Certificates explain exactly how to set up your applicationhost.config site entry to allow the app to run in either ssl or standard http.

One of the things he recommends is putting two binding entries for the site. This is what I did.

            <bindings>
                <binding protocol="http" bindingInformation="*:59945:localhost" />
                <binding protocol="https" bindingInformation="*:44300:localhost"/>
            </bindings>

He also recommends changing other settings as well. It worked on two of my three machines. Each time I am told to manually configure a site in the application host it usually has to do with the bindings. (example using same port for multiple web apps.)

test attribute in JSTL <c:if> tag

You can also use something like

<c:if test="${ testObject.testPropert == "testValue" }">...</c:if>

Automatically create requirements.txt

I created this bash command.

for l in $(pip freeze); do p=$(echo "$l" | cut -d'=' -f1); f=$(find . -type f -exec grep "$p" {} \; | grep 'import'); [[ ! -z "$f" ]] && echo "$l" ; done;

Python Variable Declaration

Okay, first things first.

There is no such thing as "variable declaration" or "variable initialization" in Python.

There is simply what we call "assignment", but should probably just call "naming".

Assignment means "this name on the left-hand side now refers to the result of evaluating the right-hand side, regardless of what it referred to before (if anything)".

foo = 'bar' # the name 'foo' is now a name for the string 'bar'
foo = 2 * 3 # the name 'foo' stops being a name for the string 'bar',
# and starts being a name for the integer 6, resulting from the multiplication

As such, Python's names (a better term than "variables", arguably) don't have associated types; the values do. You can re-apply the same name to anything regardless of its type, but the thing still has behaviour that's dependent upon its type. The name is simply a way to refer to the value (object). This answers your second question: You don't create variables to hold a custom type. You don't create variables to hold any particular type. You don't "create" variables at all. You give names to objects.

Second point: Python follows a very simple rule when it comes to classes, that is actually much more consistent than what languages like Java, C++ and C# do: everything declared inside the class block is part of the class. So, functions (def) written here are methods, i.e. part of the class object (not stored on a per-instance basis), just like in Java, C++ and C#; but other names here are also part of the class. Again, the names are just names, and they don't have associated types, and functions are objects too in Python. Thus:

class Example:
    data = 42
    def method(self): pass

Classes are objects too, in Python.

So now we have created an object named Example, which represents the class of all things that are Examples. This object has two user-supplied attributes (In C++, "members"; in C#, "fields or properties or methods"; in Java, "fields or methods"). One of them is named data, and it stores the integer value 42. The other is named method, and it stores a function object. (There are several more attributes that Python adds automatically.)

These attributes still aren't really part of the object, though. Fundamentally, an object is just a bundle of more names (the attribute names), until you get down to things that can't be divided up any more. Thus, values can be shared between different instances of a class, or even between objects of different classes, if you deliberately set that up.

Let's create an instance:

x = Example()

Now we have a separate object named x, which is an instance of Example. The data and method are not actually part of the object, but we can still look them up via x because of some magic that Python does behind the scenes. When we look up method, in particular, we will instead get a "bound method" (when we call it, x gets passed automatically as the self parameter, which cannot happen if we look up Example.method directly).

What happens when we try to use x.data?

When we examine it, it's looked up in the object first. If it's not found in the object, Python looks in the class.

However, when we assign to x.data, Python will create an attribute on the object. It will not replace the class' attribute.

This allows us to do object initialization. Python will automatically call the class' __init__ method on new instances when they are created, if present. In this method, we can simply assign to attributes to set initial values for that attribute on each object:

class Example:
    name = "Ignored"
    def __init__(self, name):
        self.name = name
    # rest as before

Now we must specify a name when we create an Example, and each instance has its own name. Python will ignore the class attribute Example.name whenever we look up the .name of an instance, because the instance's attribute will be found first.

One last caveat: modification (mutation) and assignment are different things!

In Python, strings are immutable. They cannot be modified. When you do:

a = 'hi '
b = a
a += 'mom'

You do not change the original 'hi ' string. That is impossible in Python. Instead, you create a new string 'hi mom', and cause a to stop being a name for 'hi ', and start being a name for 'hi mom' instead. We made b a name for 'hi ' as well, and after re-applying the a name, b is still a name for 'hi ', because 'hi ' still exists and has not been changed.

But lists can be changed:

a = [1, 2, 3]
b = a
a += [4]

Now b is [1, 2, 3, 4] as well, because we made b a name for the same thing that a named, and then we changed that thing. We did not create a new list for a to name, because Python simply treats += differently for lists.

This matters for objects because if you had a list as a class attribute, and used an instance to modify the list, then the change would be "seen" in all other instances. This is because (a) the data is actually part of the class object, and not any instance object; (b) because you were modifying the list and not doing a simple assignment, you did not create a new instance attribute hiding the class attribute.

What is the best Java QR code generator library?

QRGen is a good library that creates a layer on top of ZXing and makes QR Code generation in Java a piece of cake.

How do I replace a character at a particular index in JavaScript?

You can use the following function to replace Character or String at a particular position of a String. To replace all the following match cases use String.prototype.replaceAllMatches() function.

String.prototype.replaceMatch = function(matchkey, replaceStr, matchIndex) {
    var retStr = this, repeatedIndex = 0;
    for (var x = 0; (matchkey != null) && (retStr.indexOf(matchkey) > -1); x++) {
        if (repeatedIndex == 0 && x == 0) {
            repeatedIndex = retStr.indexOf(matchkey);
        } else { // matchIndex > 0
            repeatedIndex = retStr.indexOf(matchkey, repeatedIndex + 1);
        }
        if (x == matchIndex) {
            retStr = retStr.substring(0, repeatedIndex) + replaceStr + retStr.substring(repeatedIndex + (matchkey.length));
            matchkey = null; // To break the loop.
        }
    }
    return retStr;
};

Test:

var str = "yash yas $dfdas.**";

console.log('Index Matched replace : ', str.replaceMatch('as', '*', 2) );
console.log('Index Matched replace : ', str.replaceMatch('y', '~', 1) );

Output:

Index Matched replace :  yash yas $dfd*.**
Index Matched replace :  yash ~as $dfdas.**

How can I set the default timezone in node.js?

You could enforce the Node.js process timezone by setting the environment variable TZ to UTC

So all time will be measured in UTC+00:00

Full list: https://en.wikipedia.org/wiki/List_of_tz_database_time_zones

Example package.json:

{
  "scripts": {
    "start": "TZ='UTC' node index.js"
  }
}

How to define relative paths in Visual Studio Project?

I have used a syntax like this before:

$(ProjectDir)..\headers

..\headers

As other have pointed out, the starting directory is the one your project file is in(vcproj or vcxproj), not where your main code is located.

Corrupt jar file

This regularly occurs when you change the extension on the JAR for ZIP, extract the zip content and make some modifications on files such as changing the MANIFEST.MF file which is a very common case, many times Eclipse doesn't generate the MANIFEST file as we want, or maybe we would like to modify the CLASS-PATH or the MAIN-CLASS values of it.

The problem occurs when you zip back the folder.

A valid Runnable/Executable JAR has the next structure:

myJAR (Main-Directory)
    |-META-INF (Mandatory)
             |-MANIFEST.MF (Mandatory Main-class: com.MainClass)
    |-com 
         |-MainClass.class (must to implement the main method, mandatory)
    |-properties files (optional)
    |-etc (optional)

If your JAR complies with these rules it will work doesn't matter if you build it manually by using a ZIP tool and then you changed the extension back to .jar

Once you're done try execute it on the command line using:

java -jar myJAR.jar

When you use a zip tool to unpack, change files and zip again, normally the JAR structure changes to this structure which is incorrect, since another directory level is added on the top of the file system making it a corrupted file as is shown below:

**myJAR (Main-Directory)
    |-myJAR (creates another directory making the file corrupted)**
          |-META-INF (Mandatory)
                   |-MANIFEST.MF (Mandatory Main-class: com.MainClass)
          |-com 
              |-MainClass.class (must to implement the main method, mandatory)
          |-properties files (optional)
          |-etc (optional)

Remove a parameter to the URL with JavaScript

function removeParam(parameter)
{
  var url=document.location.href;
  var urlparts= url.split('?');

 if (urlparts.length>=2)
 {
  var urlBase=urlparts.shift(); 
  var queryString=urlparts.join("?"); 

  var prefix = encodeURIComponent(parameter)+'=';
  var pars = queryString.split(/[&;]/g);
  for (var i= pars.length; i-->0;)               
      if (pars[i].lastIndexOf(prefix, 0)!==-1)   
          pars.splice(i, 1);
  url = urlBase+'?'+pars.join('&');
  window.history.pushState('',document.title,url); // added this line to push the new url directly to url bar .

}
return url;
}

This will resolve your problem

how to delete the content of text file without deleting itself

Just print an empty string into the file:

PrintWriter writer = new PrintWriter(file);
writer.print("");
writer.close();

Single Form Hide on Startup

Why do it like that at all?

Why not just start like a console app and show the form when necessary? There's nothing but a few references separating a console app from a forms app.

No need in being greedy and taking the memory needed for the form when you may not even need it.

make div's height expand with its content

I'm running into this on a project myself - I had a table inside a div that was spilling out of the bottom of the div. None of the height fixes I tried worked, but I found a weird fix for it, and that is to put a paragraph at the bottom of the div with just a period in it. Then style the "color" of the text to be the same as the background of the container. Worked neat as you please and no javascript required. A non-breaking space will not work - nor does a transparent image.

Apparently it just needed to see that there is some content below the table in order to stretch to contain it. I wonder if this will work for anyone else.

This is the sort of thing that makes designers resort to table-based layouts - the amount of time I've spent figuring this stuff out and making it cross-browser compatible is driving me crazy.

connecting to mysql server on another PC in LAN

You should use this:

>mysql -u user -h 192.168.1.2 -P 3306 -ppassword

or this:

>mysql -u user -h 192.168.1.2 -ppassword

...because 3306 is a default port number.

mysql Options

Why is there no xrange function in Python3?

Python3's range is Python2's xrange. There's no need to wrap an iter around it. To get an actual list in Python3, you need to use list(range(...))

If you want something that works with Python2 and Python3, try this

try:
    xrange
except NameError:
    xrange = range

Maven artifact and groupId naming

Your convention seems to be reasonable. If I were searching for your framework in the Maven repo, I would look for awesome-inhouse-framework-x.y.jar in com.mycompany.awesomeinhouseframework group directory. And I would find it there according to your convention.

Two simple rules work for me:

reverse-domain-packages for groupId (since such are quite unique) with all the constrains regarding Java packages names
project name as artifactId (keeping in mind that it should be jar-name friendly i.e. not contain characters that maybe invalid for a file name or just look weird)

Can I dispatch an action in reducer?

redux-loop takes a cue from Elm and provides this pattern.

php.ini: which one?

Although Pascal's answer was detailed and informative it failed to mention some key information in the assumption that everyone knows how to use phpinfo()

For those that don't:

Navigate to your webservers root folder such as /var/www/

Within this folder create a text file called info.php

Edit the file and type phpinfo()

Navigate to the file such as: http://www.example.com/info.php

Here you will see the php.ini path under Loaded Configuration File:

Make sure you delete info.php when you are done.

Handle ModelState Validation in ASP.NET Web API

    public class ValidateModelAttribute : ActionFilterAttribute
    {
        public override void OnActionExecuting(HttpActionContext actionContext)
        {
            if (actionContext.ModelState.IsValid == false)
            {
                actionContext.Response = actionContext.Request.CreateErrorResponse(
                    HttpStatusCode.BadRequest, actionContext.ModelState);
            }
        }
    }

...

    [ValidateModel]
    public HttpResponseMessage Post([FromBody]AnyModel model)
    {

Javascript

$.ajax({
        type: "POST",
        url: "/api/xxxxx",
        async: 'false',
        contentType: "application/json; charset=utf-8",
        data: JSON.stringify(data),
        error: function (xhr, status, err) {
            if (xhr.status == 400) {
                DisplayModelStateErrors(xhr.responseJSON.ModelState);
            }
        },
....


function DisplayModelStateErrors(modelState) {
    var message = "";
    var propStrings = Object.keys(modelState);

    $.each(propStrings, function (i, propString) {
        var propErrors = modelState[propString];
        $.each(propErrors, function (j, propError) {
            message += propError;
        });
        message += "\n";
    });

    alert(message);
};

How to write loop in a Makefile?

The following will do it if, as I assume by your use of ./a.out, you're on a UNIX-type platform.

for number in 1 2 3 4 ; do \
    ./a.out $$number ; \
done

Test as follows:

target:
    for number in 1 2 3 4 ; do \
        echo $$number ; \
    done

produces:

For bigger ranges, use:

target:
    number=1 ; while [[ $$number -le 10 ]] ; do \
        echo $$number ; \
        ((number = number + 1)) ; \
    done

This outputs 1 through 10 inclusive, just change the while terminating condition from 10 to 1000 for a much larger range as indicated in your comment.

Nested loops can be done thus:

target:
    num1=1 ; while [[ $$num1 -le 4 ]] ; do \
        num2=1 ; while [[ $$num2 -le 3 ]] ; do \
            echo $$num1 $$num2 ; \
            ((num2 = num2 + 1)) ; \
        done ; \
        ((num1 = num1 + 1)) ; \
    done

producing:

2D cross-platform game engine for Android and iOS?

Here is just a reply from Richard Pickup on LinkedIn to a similar question of mine:

I've used cocos 2dx marmalade and unity on both iOS and android. For 2d games cocos2dx is the way to go every time. Unity is just too much overkill for 2d games and as already stated marmalade is just a thin abstraction layer not really a game engine. You can even run cocos2d on top of marmalade. My approach would be to use cocos2dx on iOS and android then in future run cocosd2dx code on top of marmalade as an easy way to port to bb10 and win phone 7

Android: show/hide status bar/power bar

Do you have the fullscreen theme set in the manifest?

android:theme="@android:style/Theme.NoTitleBar.Fullscreen"

I don't think you'll be able to go fullscreen without this.

I would use the following to add and remove the fullscreen flag:

// Hide status bar
getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
// Show status bar
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);

correct configuration for nginx to localhost?

Fundamentally you hadn't declare location which is what nginx uses to bind URL with resources.

 server {
            listen       80;
            server_name  localhost;

            access_log  logs/localhost.access.log  main;

            location / {
                root /var/www/board/public;
                index index.html index.htm index.php;
            }
       }

How does DISTINCT work when using JPA and Hibernate

Update: See the top-voted answer please.

My own is currently obsolete. Only kept here for historical reasons.

Distinct in HQL is usually needed in Joins and not in simple examples like your own.

location.host vs location.hostname and cross-browser compatibility?

As a little memo: the interactive link anatomy

In short (assuming a location of http://example.org:8888/foo/bar#bang):

hostname gives you example.org
host gives you example.org:8888

Is there a Google Voice API?

Well... These are PHP. There is an sms one from google here.

And github has one here.

Another sms one is here. However, this one has a lot more code, so it may take up more space.

Read lines from a text file but skip the first two lines

Dim sFileName As String
Dim iFileNum As Integer
Dim sBuf As String
Dim Fields as String
Dim TempStr as String

sFileName = "c:\fields.ini"
''//Does the file exist?
If Len(Dir$(sFileName)) = 0 Then
    MsgBox ("Cannot find fields.ini")
End If

iFileNum = FreeFile()
Open sFileName For Input As iFileNum

''//This part skips the first two lines
if not(EOF(iFileNum)) Then Line Input #iFilenum, TempStr
if not(EOF(iFileNum)) Then Line Input #iFilenum, TempStr

Do While Not EOF(iFileNum)
    Line Input #iFileNum, Fields

    MsgBox (Fields)
Loop

Copy Files from Windows to the Ubuntu Subsystem

You should be able to access your windows system under the /mnt directory. For example inside of bash, use this to get to your pictures directory:

cd /mnt/c/Users/<ubuntu.username>/Pictures

Hope this helps!

Subdomain on different host

You just need to add an "A" record in the DNS manager on Godaddy. In that "A" record put your IP from dreamhost.

I know this works since I'm doing the very same thing.

How can I convert a string to a float in mysql?

It turns out I was just missing DECIMAL on the CAST() description:

DECIMAL[(M[,D])]

Converts a value to DECIMAL data type. The optional arguments M and D specify the precision (M specifies the total number of digits) and the scale (D specifies the number of digits after the decimal point) of the decimal value. The default precision is two digits after the decimal point.

Thus, the following query worked:

UPDATE table SET
latitude = CAST(old_latitude AS DECIMAL(10,6)),
longitude = CAST(old_longitude AS DECIMAL(10,6));

Scanner method to get a char

sc.next().charat(0).........is the method of entering character by user based on the number entered at the run time

example: sc.next().charat(2)------------>>>>>>>>

How to get 0-padded binary representation of an integer in java?

You can use Apache Commons StringUtils. It offers methods for padding strings:

StringUtils.leftPad(Integer.toBinaryString(1), 16, '0');

How to set the java.library.path from Eclipse

For a given application launch, you can do it as jim says.

If you want to set it for the entire workspace, you can also set it under

Window->
  Preferences->
    Java->
      Installed JREs

Each JRE has a "Default VM arguments" (which I believe are completely ignored if any VM args are set for a run configuration.)

You could even set up different JRE/JDKs with different parameters and have some projects use one, other projects use another.

Apache 13 permission denied in user's home directory

Can't you set the Loglevel in httpd.conf to debug? (I'm using FreeBSD)

ee usr/local/etc/apache22/httpd.conf

change loglevel :

'LogLevel: Control the number of messages logged to the error_log. Possible values include: debug, info, notice, warn, error, crit, alert, emerg.'

Try changing to debug and re-checking the error log after that.

What is stdClass in PHP?

stdClass is not an anonymous class or anonymous object

Answers here includes expressions that stdClass is an anonymous class or even anonymous object. It's not a true.

stdClass is just a regular predefined class. You can check this using instanceof operator or function get_class. Nothing special goes here. PHP uses this class when casting other values to object.

In many cases where stdClass is used by the programmers the array is better option, because of useful functions and the fact that this usecase represents the data structure not a real object.

Is there any simple way to convert .xls file to .csv file? (Excel)

Here's a C# method to do this. Remember to add your own error handling - this mostly assumes that things work for the sake of brevity. It's 4.0+ framework only, but that's mostly because of the optional worksheetNumber parameter. You can overload the method if you need to support earlier versions.

static void ConvertExcelToCsv(string excelFilePath, string csvOutputFile, int worksheetNumber = 1) {
   if (!File.Exists(excelFilePath)) throw new FileNotFoundException(excelFilePath);
   if (File.Exists(csvOutputFile)) throw new ArgumentException("File exists: " + csvOutputFile);

   // connection string
   var cnnStr = String.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties=\"Excel 8.0;IMEX=1;HDR=NO\"", excelFilePath);
   var cnn = new OleDbConnection(cnnStr);

   // get schema, then data
   var dt = new DataTable();
   try {
      cnn.Open();
      var schemaTable = cnn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
      if (schemaTable.Rows.Count < worksheetNumber) throw new ArgumentException("The worksheet number provided cannot be found in the spreadsheet");
      string worksheet = schemaTable.Rows[worksheetNumber - 1]["table_name"].ToString().Replace("'", "");
      string sql = String.Format("select * from [{0}]", worksheet);
      var da = new OleDbDataAdapter(sql, cnn);
      da.Fill(dt);
   }
   catch (Exception e) {
      // ???
      throw e;
   }
   finally {
      // free resources
      cnn.Close();
   }

   // write out CSV data
   using (var wtr = new StreamWriter(csvOutputFile)) {
      foreach (DataRow row in dt.Rows) {
         bool firstLine = true;
         foreach (DataColumn col in dt.Columns) {
            if (!firstLine) { wtr.Write(","); } else { firstLine = false; }
            var data = row[col.ColumnName].ToString().Replace("\"", "\"\"");
            wtr.Write(String.Format("\"{0}\"", data));
         }
         wtr.WriteLine();
      }
   }
}

Change url query string value using jQuery

If you only need to modify the page num you can replace it:

var newUrl = location.href.replace("page="+currentPageNum, "page="+newPageNum);

Pandas left outer join multiple dataframes on multiple columns

Merge them in two steps, df1 and df2 first, and then the result of that to df3.

In [33]: s1 = pd.merge(df1, df2, how='left', on=['Year', 'Week', 'Colour'])

I dropped year from df3 since you don't need it for the last join.

In [39]: df = pd.merge(s1, df3[['Week', 'Colour', 'Val3']],
                       how='left', on=['Week', 'Colour'])

In [40]: df
Out[40]: 
   Year Week Colour  Val1  Val2 Val3
0  2014    A    Red    50   NaN  NaN
1  2014    B    Red    60   NaN   60
2  2014    B  Black    70   100   10
3  2014    C    Red    10    20  NaN
4  2014    D  Green    20   NaN   20

[5 rows x 6 columns]

builtins.TypeError: must be str, not bytes

Convert binary file to base64 & vice versa. Prove in python 3.5.2

import base64

read_file = open('/tmp/newgalax.png', 'rb')
data = read_file.read()

b64 = base64.b64encode(data)

print (b64)

# Save file
decode_b64 = base64.b64decode(b64)
out_file = open('/tmp/out_newgalax.png', 'wb')
out_file.write(decode_b64)

# Test in python 3.5.2

how to convert .java file to a .class file

To get a .class file you have to compile the .java file.

The command for this is javac. The manual for this is found here (Windows)

In short:

javac File.java

Jquery: how to sleep or delay?

If you can't use the delay method as Robert Harvey suggested, you can use setTimeout.

Eg.

setTimeout(function() {$("#test").animate({"top":"-=80px"})} , 1500); // delays 1.5 sec
setTimeout(function() {$("#test").animate({"opacity":"0"})} , 1500 + 1000); // delays 1 sec after the previous one

How to resolve this System.IO.FileNotFoundException

I hate to point out the obvious, but System.IO.FileNotFoundException means the program did not find the file you specified. So what you need to do is check what file your code is looking for in production.

To see what file your program is looking for in production (look at the FileName property of the exception), try these techniques:

Then look at the file system on the machine and see if the file exists. Most likely the case is that it doesn't exist.

How do I create a unique ID in Java?

IMHO aperkins provided an an elegant solution cause is native and use less code. But if you need a shorter ID you can use this approach to reduce the generated String length:

// usage: GenerateShortUUID.next();
import java.util.UUID;

public class GenerateShortUUID() {

  private GenerateShortUUID() { } // singleton

  public static String next() {
     UUID u = UUID.randomUUID();
     return toIDString(u.getMostSignificantBits()) + toIDString(u.getLeastSignificantBits());
  }

  private static String toIDString(long i) {
      char[] buf = new char[32];
      int z = 64; // 1 << 6;
      int cp = 32;
      long b = z - 1;
      do {
          buf[--cp] = DIGITS66[(int)(i & b)];
          i >>>= 6;
      } while (i != 0);
      return new String(buf, cp, (32-cp));
  }

 // array de 64+2 digitos 
 private final static char[] DIGITS66 = {
    '0','1','2','3','4','5','6','7','8','9',        'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',
    'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
    '-','.','_','~'
  };

}

"message failed to fetch from registry" while trying to install any module

@therefromhere's answer is the best one. However Node versions have moved ever onwards and upwards, and the versioning was complicated by the remerge of io.js. Following the steps in his answer, you will end up with Node version 0.10.25 - not the most recent version.

You should still purge any existing node/npm packages with

sudo apt-get purge nodejs npm

and then go and look at the nodesource deb install page at https://github.com/nodesource/distributions#debinstall.

All Node.js versions are listed on the above page with the Linux commands to install them. And these packages will work on both Debian and Ubuntu.

P.S. If you want to run Node v4.4 or higher on Ubuntu Precise or Debian Wheezy, you should review the information about running on older distros.

P.P.S. If your apt-get is failing, the script will not complete (Google references were failing my apt-get update). You should see messages about the NodeSource signing key being added to your keyring and a final message instructing you to Run 'apt-get install nodejs' to install Node.js.

P.P.P.S. npm is installed with node. Once installed, you can update to the latest npm with sudo npm install npm -g

Pandas read_sql with parameters

The read_sql docs say this params argument can be a list, tuple or dict (see docs).

To pass the values in the sql query, there are different syntaxes possible: ?, :1, :name, %s, %(name)s (see PEP249).
But not all of these possibilities are supported by all database drivers, which syntax is supported depends on the driver you are using (psycopg2 in your case I suppose).

In your second case, when using a dict, you are using 'named arguments', and according to the psycopg2 documentation, they support the %(name)s style (and so not the :name I suppose), see http://initd.org/psycopg/docs/usage.html#query-parameters.
So using that style should work:

df = psql.read_sql(('select "Timestamp","Value" from "MyTable" '
                     'where "Timestamp" BETWEEN %(dstart)s AND %(dfinish)s'),
                   db,params={"dstart":datetime(2014,6,24,16,0),"dfinish":datetime(2014,6,24,17,0)},
                   index_col=['Timestamp'])

How to make a HTTP request using Ruby on Rails?

Here is the code that works if you are making a REST api call behind a proxy:

require "uri"
require 'net/http'

proxy_host = '<proxy addr>'
proxy_port = '<proxy_port>'
proxy_user = '<username>'
proxy_pass = '<password>'

uri = URI.parse("https://saucelabs.com:80/rest/v1/users/<username>")
proxy = Net::HTTP::Proxy(proxy_host, proxy_port, proxy_user, proxy_pass)

req = Net::HTTP::Get.new(uri.path)
req.basic_auth(<sauce_username>,<sauce_password>)

result = proxy.start(uri.host,uri.port) do |http|
http.request(req)
end

puts result.body

Database cluster and load balancing

From SQL Server point of view:

Clustering will give you an active - passive configuration. Meaning in a 2 node cluster, one of them will be the active (serving) and the other one will be passive (waiting to take over when the active node fails). It's a high availability from hardware point of view.

You can have an active-active cluster, but it will require multiple instances of SQL Server running on each node. (i.e. Instance 1 on Node A failing over to Instance 2 on Node B, and instance 1 on Node B failing over to instance 2 on Node A).

Load balancing (at least from SQL Server point of view) does not exists (at least in the same sense of web server load balancing). You can't balance load that way. However, you can split your application to run on some database on server 1 and also run on some database on server 2, etc. This is the primary mean of "load balancing" in SQL world.

Windows batch script to move files

move c:\Sourcefoldernam\*.* e:\destinationFolder

^ This did not work for me for some reason

But when I tried using quotation marks, it suddenly worked:

move "c:\Sourcefoldernam\*.*" "e:\destinationFolder"

I think its because my directory had spaces in one of the folders. So if it doesn't work for you, try with quotation marks!

What techniques can be used to define a class in JavaScript, and what are their trade-offs?

A base

function Base(kind) {
    this.kind = kind;
}

A class

// Shared var
var _greeting;

(function _init() {
    Class.prototype = new Base();
    Class.prototype.constructor = Class;
    Class.prototype.log = function() { _log.apply(this, arguments); }
    _greeting = "Good afternoon!";
})();

function Class(name, kind) {
    Base.call(this, kind);
    this.name = name;
}

// Shared function
function _log() {
    console.log(_greeting + " Me name is " + this.name + " and I'm a " + this.kind);
}

Action

var c = new Class("Joe", "Object");
c.log(); // "Good afternoon! Me name is Joe and I'm a Object"

Check if a Python list item contains a string inside another string

mylist=['abc','def','ghi','abc']

pattern=re.compile(r'abc') 

pattern.findall(mylist)

Pandas : compute mean or std (standard deviation) over entire dataframe

You could convert the dataframe to be a single column with stack (this changes the shape from 5x3 to 15x1) and then take the standard deviation:

df.stack().std()         # pandas default degrees of freedom is one

Alternatively, you can use values to convert from a pandas dataframe to a numpy array before taking the standard deviation:

df.values.std(ddof=1)    # numpy default degrees of freedom is zero

Unlike pandas, numpy will give the standard deviation of the entire array by default, so there is no need to reshape before taking the standard deviation.

A couple of additional notes:

The numpy approach here is a bit faster than the pandas one, which is generally true when you have the option to accomplish the same thing with either numpy or pandas. The speed difference will depend on the size of your data, but numpy was roughly 10x faster when I tested a few different sized dataframes on my laptop (numpy version 1.15.4 and pandas version 0.23.4).
The numpy and pandas approaches here will not give exactly the same answers, but will be extremely close (identical at several digits of precision). The discrepancy is due to slight differences in implementation behind the scenes that affect how the floating point values get rounded.

private final static attribute vs private final attribute

While the other answers seem to make it pretty clear that there is generally no reason to use non-static constants, I couldn't find anyone pointing out that it is possible to have various instances with different values on their constant variables.

Consider the following example:

public class TestClass {
    private final static double NUMBER = Math.random();

    public TestClass () {
        System.out.println(NUMBER);
    }
}

Creating three instances of TestClass would print the same random value three times, since only one value is generated and stored into the static constant.

However, when trying the following example instead:

public class TestClass {
    private final double NUMBER = Math.random();

    public TestClass () {
        System.out.println(NUMBER);
    }
}

Creating three instances of TestClass would now print three different random values, because each instance has its own randomly generated constant value.

I can't think of any situation where it would be really useful to have different constant values on different instances, but I hope this helps pointing out that there is a clear difference between static and non-static finals.

Do Swift-based applications work on OS X 10.9/iOS 7 and lower?

I read all answers that said: No, Swift does not work with less than iOS 7. But I said YES, I just created a Swift project that does run in Xcode 5 with 6.0 deployment target.

I just create a demo project in Xcode 6 BETA with the Swift programming language selected.
Close Xcode 6 beta, and I open this demo project in Xcode 5 with deployment target 6.0
And also select simulator 6.1.

Then that project runs well in simulator 6.1. My MacOS X is 10.9.3, so I said yes, that runs in lower than iOS 7. with 10.9.3 Mac OS X.

Here it is a screenshot of the simulator:

Enter image description here

Here is a demo as well

Android Studio how to run gradle sync manually?

I have a trouble may proof gradlew clean is not equal to ADT build clean. And Now I am struggling to get it fixed.

Here is what I got: I set a configProductID=11111 from my gradle.properties, from my build.gradle, I add

resValue "string", "ProductID", configProductID

If I do a build clean from ADT, the resource R.string.ProductID can be generated. Then I can do bellow command successfully.

gradlew assembleDebug

But, as I am trying to setup build server, I don't want help from ADT IDE, so I need to avoid using ADT build clean. Here comes my problem. Now I change my resource name from "ProductID" to "myProductID", I do:

gradlew clean

I get error

PS D:\work\wctposdemo> .\gradlew.bat clean

FAILURE: Build failed with an exception.

* Where:
Build file 'D:\work\wctposdemo\app\build.gradle'

* What went wrong:
Could not compile build file 'D:\work\wctposdemo\app\build.gradle'.
> startup failed:
  General error during semantic analysis: Unsupported class file major version 57

If I try with:

.\gradlew.bat --recompile-scripts

I just get error of

Unknown command-line option '--recompile-scripts'.

Unable to connect to mongodb Error: couldn't connect to server 127.0.0.1:27017 at src/mongo/shell/mongo.js:L112

Start mongod server first

mongod

Open another terminal window

Start mongo shell

mongo

Sorting multiple keys with Unix sort

Use the -k option (or --key=POS1[,POS2]). It can appear multiple times and each key can have global options (such as n for numeric sort)

How do I create a view controller file after creating a new view controller?

To add new ViewController once you have have an existing ViewController, follow below step:

Click on background of Main.storyboard.
Search and select ViewController from object library at the utility window.
Drag and drop it in background to create a new ViewController.

How to use HTTP GET in PowerShell?

Downloading Wget is not necessary; the .NET Framework has web client classes built in.

$wc = New-Object system.Net.WebClient;
$sms = Read-Host "Enter SMS text";
$sms = [System.Web.HttpUtility]::UrlEncode($sms);
$smsResult = $wc.downloadString("http://smsserver/SNSManager/msgSend.jsp?uid&to=smartsms:*+001XXXXXX&msg=$sms&encoding=windows-1255")

How can I convert a timestamp from yyyy-MM-ddThh:mm:ss:SSSZ format to MM/dd/yyyy hh:mm:ss.SSS format? From ISO8601 to UTC

Yes. you can use SimpleDateFormat like this.

SimpleDateFormat formatter, FORMATTER;
formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
String oldDate = "2011-03-10T11:54:30.207Z";
Date date = formatter.parse(oldDate.substring(0, 24));
FORMATTER = new SimpleDateFormat("dd-MMM-yyyy HH:mm:ss.SSS");
System.out.println("OldDate-->"+oldDate);
System.out.println("NewDate-->"+FORMATTER.format(date));

Output OldDate-->2011-03-10T11:54:30.207Z NewDate-->10-Mar-2011 11:54:30.207

Use IntelliJ to generate class diagram

Use Diagrams | Show Diagram... from the context menu of a package. Invoking it on the project root will show module dependencies diagram.

If you need multiple packages, you can drag & drop them to the already opened diagram for the first package and press e to expand it.

Note: This feature is available in the Ultimate Edition, not the free Community Edition.

How to initialize a private static const map in C++?

I did it! :)

Works fine without C++11

class MyClass {
    typedef std::map<std::string, int> MyMap;

    struct T {
        const char* Name;
        int Num;

        operator MyMap::value_type() const {
            return std::pair<std::string, int>(Name, Num);
        }
    };

    static const T MapPairs[];
    static const MyMap TheMap;
};

const MyClass::T MyClass::MapPairs[] = {
    { "Jan", 1 }, { "Feb", 2 }, { "Mar", 3 }
};

const MyClass::MyMap MyClass::TheMap(MapPairs, MapPairs + 3);

ng-model for `<input type="file"/>` (with directive DEMO)

I had to do same on multiple input, so i updated @Endy Tjahjono method. It returns an array containing all readed files.

  .directive("fileread", function () {
    return {
      scope: {
        fileread: "="
      },
      link: function (scope, element, attributes) {
        element.bind("change", function (changeEvent) {
          var readers = [] ,
              files = changeEvent.target.files ,
              datas = [] ;
          for ( var i = 0 ; i < files.length ; i++ ) {
            readers[ i ] = new FileReader();
            readers[ i ].onload = function (loadEvent) {
              datas.push( loadEvent.target.result );
              if ( datas.length === files.length ){
                scope.$apply(function () {
                  scope.fileread = datas;
                });
              }
            }
            readers[ i ].readAsDataURL( files[i] );
          }
        });

      }
    }
  });

How to get current memory usage in android?

final long usedMemInMB=(runtime.totalMemory() - runtime.freeMemory()) / 1048576L;
final long maxHeapSizeInMB=runtime.maxMemory() / 1048576L;
final long availHeapSizeInMB = maxHeapSizeInMB - usedMemInMB;

It is a strange code. It return MaxMemory - (totalMemory - freeMemory). If freeMemory equals 0, then the code will return MaxMemory - totalMemory, so it can more or equals 0. Why freeMemory not used?

Create directory if it does not exist

I had the exact same problem. You can use something like this:

$local = Get-Location;
$final_local = "C:\Processing";

if(!$local.Equals("C:\"))
{
    cd "C:\";
    if((Test-Path $final_local) -eq 0)
    {
        mkdir $final_local;
        cd $final_local;
        liga;
    }

    ## If path already exists
    ## DB Connect
    elseif ((Test-Path $final_local) -eq 1)
    {
        cd $final_local;
        echo $final_local;
        liga;  (function created by you TODO something)
    }
}

Regular expressions inside SQL Server

Try this

select * from mytable
where p1 not like '%[^0-9]%' and substring(p1,1,1)='5'

Of course, you'll need to adjust the substring value, but the rest should work...

Generate an integer sequence in MySQL

Sequence of numbers between 1 and 100.000:

SELECT e*10000+d*1000+c*100+b*10+a n FROM
(select 0 a union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) t1,
(select 0 b union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) t2,
(select 0 c union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) t3,
(select 0 d union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) t4,
(select 0 e union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) t5
order by 1

I use it to audit if some number is out of sequence, something like this:

select * from (
    select 121 id
    union all select 123
    union all select 125
    union all select 126
    union all select 127
    union all select 128
    union all select 129
) a
right join (
    SELECT e*10000+d*1000+c*100+b*10+a n FROM
    (select 0 a union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) t1,
    (select 0 b union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) t2,
    (select 0 c union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) t3,
    (select 0 d union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) t4,
    (select 0 e union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) t5
    order by 1
) seq on seq.n=a.id
where seq.n between 121 and 129
and   id is null

The result will be the gap of number 122 and 124 of sequence between 121 and 129:

id     n
----   ---
null   122
null   124

Maybe it helps someone!

SSIS Connection Manager Not Storing SQL Password

Check the text contents of the connection manager file itself, the password field might be configured in the Project.params file, in which case entering the password into the connection manager window will cause it to not save.

Why is HttpClient BaseAddress not working?

Reference Resolution is described by RFC 3986 Uniform Resource Identifier (URI): Generic Syntax. And that is exactly how it supposed to work. To preserve base URI path you need to add slash at the end of the base URI and remove slash at the beginning of relative URI.

If base URI contains non-empty path, merge procedure discards it's last part (after last /). Relevant section:

5.2.3. Merge Paths

The pseudocode above refers to a "merge" routine for merging a relative-path reference with the path of the base URI. This is accomplished as follows:

If the base URI has a defined authority component and an empty path, then return a string consisting of "/" concatenated with the reference's path; otherwise

return a string consisting of the reference's path component appended to all but the last segment of the base URI's path (i.e., excluding any characters after the right-most "/" in the base URI path, or excluding the entire base URI path if it does not contain any "/" characters).

If relative URI starts with a slash, it is called a absolute-path relative URI. In this case merge procedure ignore all base URI path. For more information check 5.2.2. Transform References section.

EditText non editable

android:editable="false" should work, but it is deprecated, you should be using android:inputType="none" instead.

Alternatively, if you want to do it in the code you could do this :

EditText mEdit = (EditText) findViewById(R.id.yourid);
mEdit.setEnabled(false);

This is also a viable alternative :

EditText mEdit = (EditText) findViewById(R.id.yourid);
mEdit.setKeyListener(null);

If you're going to make your EditText non-editable, may I suggest using the TextView widget instead of the EditText, since using a EditText seems kind of pointless in that case.

EDIT: Altered some information since I've found that android:editable is deprecated, and you should use android:inputType="none", but there is a bug about it on android code; So please check this.

How to use jQuery to select a dropdown option?

The solution:

$("#element-id").val('the value of the option');

How to submit a form on enter when the textarea has focus?

<form id="myform">
    <input type="textbox" id="field"/>
    <input type="button" value="submit">
</form>

<script>
    $(function () {
        $("#field").keyup(function (event) {
            if (event.which === 13) {
                document.myform.submit();
            }
        }
    });
</script>

How to output git log with the first line only?

if you only want the first line of the messages (the subject):

git log --pretty=format:"%s"

and if you want all the messages on this branch going back to master:

git log --pretty=format:"%s" master..HEAD

Last but not least, if you want to add little bullets for quick markdown release notes:

git log --pretty=format:"- %s" master..HEAD

How to pass a vector to a function?

You're using the argument as a reference but actually it's a pointer. Change vector<int>* to vector<int>&. And you should really set search4 to something before using it.

Get time difference between two dates in seconds

Define two dates using new Date(). Calculate the time difference of two dates using date2. getTime() – date1. getTime(); Calculate the no. of days between two dates, divide the time difference of both the dates by no. of milliseconds in a day (10006060*24)

Pass Method as Parameter using C#

You can use the Func delegate in .net 3.5 as the parameter in your RunTheMethod method. The Func delegate allows you to specify a method that takes a number of parameters of a specific type and returns a single argument of a specific type. Here is an example that should work:

public class Class1
{
    public int Method1(string input)
    {
        //... do something
        return 0;
    }

    public int Method2(string input)
    {
        //... do something different
        return 1;
    }

    public bool RunTheMethod(Func<string, int> myMethodName)
    {
        //... do stuff
        int i = myMethodName("My String");
        //... do more stuff
        return true;
    }

    public bool Test()
    {
        return RunTheMethod(Method1);
    }
}

Angular ReactiveForms: Producing an array of checkbox values?

My solution - solved it for Angular 5 with Material View
The connection is through the

formArrayName="notification"

(change)="updateChkbxArray(n.id, $event.checked, 'notification')"

This way it can work for multiple checkboxes arrays in one form. Just set the name of the controls array to connect each time.

_x000D_

constructor(_x000D_
  private fb: FormBuilder,_x000D_
  private http: Http,_x000D_
  private codeTableService: CodeTablesService) {_x000D_
_x000D_
  this.codeTableService.getnotifications().subscribe(response => {_x000D_
      this.notifications = response;_x000D_
    })_x000D_
    ..._x000D_
}_x000D_
_x000D_
_x000D_
createForm() {_x000D_
  this.form = this.fb.group({_x000D_
    notification: this.fb.array([])..._x000D_
  });_x000D_
}_x000D_
_x000D_
ngOnInit() {_x000D_
  this.createForm();_x000D_
}_x000D_
_x000D_
updateChkbxArray(id, isChecked, key) {_x000D_
  const chkArray = < FormArray > this.form.get(key);_x000D_
  if (isChecked) {_x000D_
    chkArray.push(new FormControl(id));_x000D_
  } else {_x000D_
    let idx = chkArray.controls.findIndex(x => x.value == id);_x000D_
    chkArray.removeAt(idx);_x000D_
  }_x000D_
}

_x000D_

<div class="col-md-12">_x000D_
  <section class="checkbox-section text-center" *ngIf="notifications  && notifications.length > 0">_x000D_
    <label class="example-margin">Notifications to send:</label>_x000D_
    <p *ngFor="let n of notifications; let i = index" formArrayName="notification">_x000D_
      <mat-checkbox class="checkbox-margin" (change)="updateChkbxArray(n.id, $event.checked, 'notification')" value="n.id">{{n.description}}</mat-checkbox>_x000D_
    </p>_x000D_
  </section>_x000D_
</div>

_x000D_

At the end you are getting to save the form with array of original records id's to save/update.

Will be happy to have any remarks for improvement.

Counting the Number of keywords in a dictionary in python

Calling len() directly on your dictionary works, and is faster than building an iterator, d.keys(), and calling len() on it, but the speed of either will negligible in comparison to whatever else your program is doing.

d = {x: x**2 for x in range(1000)}

len(d)
# 1000

len(d.keys())
# 1000

%timeit len(d)
# 41.9 ns ± 0.244 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)

%timeit len(d.keys())
# 83.3 ns ± 0.41 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)

Visual Studio: How to show Overloads in IntelliSense?

Every once and a while the suggestions above stop working, if I restart Visual Studio they start working again though.

Find out if string ends with another string in C++

bool EndsWith(const std::string& data, const std::string& suffix)
{
    return data.find(suffix, data.size() - suffix.size()) != string::npos;
}

Tests

#include <iostream>
int main()
{
   cout << EndsWith(u8"o!hello!1", u8"o!") << endl; 
   cout << EndsWith(u8"o!hello!", u8"o!") << endl; 
   cout << EndsWith(u8"hello!", u8"o!") << endl; 
   cout << EndsWith(u8"o!hello!o!", u8"o!") << endl; 
   return 0;
}

Output

How to run a .awk file?

Put the part from BEGIN....END{} inside a file and name it like my.awk.

And then execute it like below:

awk -f my.awk life.csv >output.txt

Also I see a field separator as ,. You can add that in the begin block of the .awk file as FS=","

PowerShell : retrieve JSON object by field value

Hows about this:

$json=Get-Content -Raw -Path 'my.json' | Out-String | ConvertFrom-Json
$foo="TheVariableYourUsingToSelectSomething"
$json.SomePathYouKnow.psobject.properties.Where({$_.name -eq $foo}).value

which would select from json structured

{"SomePathYouKnow":{"TheVariableYourUsingToSelectSomething": "Tada!"}

This is based on this accessing values in powershell SO question . Isn't powershell fabulous!

Is it ok to scrape data from Google results?

Google will eventually block your IP when you exceed a certain amount of requests.

Can't find AVD or SDK manager in Eclipse

Well I feel silly, but my problem was that I was in the Debug perspective and they do not show up in that perspective. Switched back to the Java perspective and viola.

How do you clear the console screen in C?

#include <conio.h>

and use

clrscr()

Memory errors and list limits?

There is no memory limit imposed by Python. However, you will get a MemoryError if you run out of RAM. You say you have 20301 elements in the list. This seems too small to cause a memory error for simple data types (e.g. int), but if each element itself is an object that takes up a lot of memory, you may well be running out of memory.

The IndexError however is probably caused because your ListTemp has got only 19767 elements (indexed 0 to 19766), and you are trying to access past the last element.

It is hard to say what you can do to avoid hitting the limit without knowing exactly what it is that you are trying to do. Using numpy might help. It looks like you are storing a huge amount of data. It may be that you don't need to store all of it at every stage. But it is impossible to say without knowing.

How to set upload_max_filesize in .htaccess?

If you are getting 500 - Internal server error that means you don't have permission to set these values by .htaccess. You have to contact your web server providers and ask to set AllowOverride Options for your host or to put these lines in their virtual host configuration file.

How can I avoid getting this MySQL error Incorrect column specifier for column COLUMN NAME?

To use AUTO_INCREMENT you need to deifne column as INT or floating-point types, not CHAR.

AUTO_INCREMENT use only unsigned value, so it's good to use UNSIGNED as well;

CREATE TABLE discussion_topics (

     topic_id INT NOT NULL unsigned AUTO_INCREMENT,
     project_id char(36) NOT NULL,
     topic_subject VARCHAR(255) NOT NULL,
     topic_content TEXT default NULL,
     date_created DATETIME NOT NULL,
     date_last_post DATETIME NOT NULL,
     created_by_user_id char(36) NOT NULL,
     last_post_user_id char(36) NOT NULL,
     posts_count char(36) default NULL,
     PRIMARY KEY (topic_id) 
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=1;

C# Create New T()

To get this i tried following code :

  protected T GetObject<T>()
    {
        T obj = default(T);
        obj =Activator.CreateInstance<T>();
        return obj ;
    }

What can cause intermittent ORA-12519 (TNS: no appropriate handler found) errors

I also had the same problem, I searched for the answers many places. I got many similar answers to change the number of process/service handlers. But I thought, what if I forgot to reset it back?

Then I tried using Thread.sleep() method after each of my connection.close();.

I don't know how, but it's working at least for me.

If any one wants to try it out and figure out how it's working then please go ahead. I would also like to know it as I am a beginner in programming world.

Delete data with foreign key in SQL Server table

Usefull script which you can delete all data in all tables of a database , replace tt with you databse name :

declare @tablename nvarchar(100)
declare c1 cursor for
SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_CATALOG='tt' AND TABLE_TYPE='BASE TABLE'

open  c1
fetch next from c1 into @tablename

while @@FETCH_STATUS = 0
    begin
    print @t1
        exec('alter table ' + @tablename + ' nocheck constraint all')
        exec('delete from ' + @tablename)
        exec ('alter table ' + @tablename + ' check constraint all')
        fetch next from c1 into @tablename
    end
close c1
DEALLOCATE c1

Clearing localStorage in javascript?

To clear sessionStorage

sessionStorage.clear();

Export/import jobs in Jenkins

Simple php script worked for me.

Export:

// add all job codes in the array
$jobs = array("job1", "job2", "job3");

foreach ($jobs as $value)
{
    fwrite(STDOUT, $value. " \n") or die("Unable to open file!");
    $path = "http://server1:8080/jenkins/job/".$value."/config.xml";
    $myfile = fopen($value.".xml", "w");
    fwrite($myfile, file_get_contents($path));
    fclose($myfile);
}

Import:

<?php

// add all job codes in the array
$jobs = array("job1", "job2", "job3");

foreach ($arr as $value)
{
    fwrite(STDOUT, $value. " \n") or die("Unable to open file!");
    $cmd = "java -jar jenkins-cli.jar -s http://server2:8080/jenkins/ create-job ".$value." < ".$value.".xml";
    echo exec($cmd);
}

MySQL: Selecting multiple fields into multiple variables in a stored procedure

==========Advise==========

@martin clayton Answer is correct, But this is an advise only.

Please avoid the use of ambiguous variable in the stored procedure.

Example :

SELECT Id, dateCreated
INTO id, datecreated
FROM products
WHERE pName = iName

The above example will cause an error (null value error)

Example give below is correct. I hope this make sense.

Example :

SELECT Id, dateCreated
INTO val_id, val_datecreated
FROM products
WHERE pName = iName

You can also make them unambiguous by referencing the table, like:

[ Credit : maganap ]

SELECT p.Id, p.dateCreated INTO id, datecreated FROM products p 
WHERE pName = iName

MySQL Error 1153 - Got a packet bigger than 'max_allowed_packet' bytes

This can be changed in your my.ini file (on Windows, located in \Program Files\MySQL\MySQL Server) under the server section, for example:

[mysqld]

max_allowed_packet = 10M

How to construct a relative path in Java from two absolute paths (or URLs)?

org.apache.ant has a FileUtils class with a getRelativePath method. Haven't tried it myself yet, but could be worthwhile to check it out.

http://javadoc.haefelinger.it/org.apache.ant/1.7.1/org/apache/tools/ant/util/FileUtils.html#getRelativePath(java.io.File, java.io.File)

Remove Trailing Spaces and Update in Columns in SQL Server

Try SELECT LTRIM(RTRIM('Amit Tech Corp '))

LTRIM - removes any leading spaces from left side of string

RTRIM - removes any spaces from right

Ex:

update table set CompanyName = LTRIM(RTRIM(CompanyName))

Java System.out.print formatting

Just use \t to space it.

Example:

System.out.println(monthlyInterest + "\t")

//as far as the two 0 in front of it just use a if else statement. ex: 
x = x+1;
if (x < 10){
    System.out.println("00" +x);
}
else if( x < 100){
    System.out.println("0" +x);
}
else{
    System.out.println(x);
}

There are other ways to do it, but this is the simplest.

How can I use optional parameters in a T-SQL stored procedure?

Five years late to the party.

It is mentioned in the provided links of the accepted answer, but I think it deserves an explicit answer on SO - dynamically building the query based on provided parameters. E.g.:

Setup

-- drop table Person
create table Person
(
    PersonId INT NOT NULL IDENTITY(1, 1) CONSTRAINT PK_Person PRIMARY KEY,
    FirstName NVARCHAR(64) NOT NULL,
    LastName NVARCHAR(64) NOT NULL,
    Title NVARCHAR(64) NULL
)
GO

INSERT INTO Person (FirstName, LastName, Title)
VALUES ('Dick', 'Ormsby', 'Mr'), ('Serena', 'Kroeger', 'Ms'), 
    ('Marina', 'Losoya', 'Mrs'), ('Shakita', 'Grate', 'Ms'), 
    ('Bethann', 'Zellner', 'Ms'), ('Dexter', 'Shaw', 'Mr'),
    ('Zona', 'Halligan', 'Ms'), ('Fiona', 'Cassity', 'Ms'),
    ('Sherron', 'Janowski', 'Ms'), ('Melinda', 'Cormier', 'Ms')
GO

Procedure

ALTER PROCEDURE spDoSearch
    @FirstName varchar(64) = null,
    @LastName varchar(64) = null,
    @Title varchar(64) = null,
    @TopCount INT = 100
AS
BEGIN
    DECLARE @SQL NVARCHAR(4000) = '
        SELECT TOP ' + CAST(@TopCount AS VARCHAR) + ' *
        FROM Person
        WHERE 1 = 1'

    PRINT @SQL

    IF (@FirstName IS NOT NULL) SET @SQL = @SQL + ' AND FirstName = @FirstName'
    IF (@LastName IS NOT NULL) SET @SQL = @SQL + ' AND FirstName = @LastName'
    IF (@Title IS NOT NULL) SET @SQL = @SQL + ' AND Title = @Title'

    EXEC sp_executesql @SQL, N'@TopCount INT, @FirstName varchar(25), @LastName varchar(25), @Title varchar(64)', 
         @TopCount, @FirstName, @LastName, @Title
END
GO

Usage

exec spDoSearch @TopCount = 3
exec spDoSearch @FirstName = 'Dick'

Pros:

easy to write and understand
flexibility - easily generate the query for trickier filterings (e.g. dynamic TOP)

Cons:

possible performance problems depending on provided parameters, indexes and data volume

Not direct answer, but related to the problem aka the big picture

Usually, these filtering stored procedures do not float around, but are being called from some service layer. This leaves the option of moving away business logic (filtering) from SQL to service layer.

One example is using LINQ2SQL to generate the query based on provided filters:

    public IList<SomeServiceModel> GetServiceModels(CustomFilter filters)
    {
        var query = DataAccess.SomeRepository.AllNoTracking;

        // partial and insensitive search 
        if (!string.IsNullOrWhiteSpace(filters.SomeName))
            query = query.Where(item => item.SomeName.IndexOf(filters.SomeName, StringComparison.OrdinalIgnoreCase) != -1);
        // filter by multiple selection
        if ((filters.CreatedByList?.Count ?? 0) > 0)
            query = query.Where(item => filters.CreatedByList.Contains(item.CreatedById));
        if (filters.EnabledOnly)
            query = query.Where(item => item.IsEnabled);

        var modelList = query.ToList();
        var serviceModelList = MappingService.MapEx<SomeDataModel, SomeServiceModel>(modelList);
        return serviceModelList;
    }

Pros:

dynamically generated query based on provided filters. No parameter sniffing or recompile hints needed
somewhat easier to write for those in the OOP world
typically performance friendly, since "simple" queries will be issued (appropriate indexes are still needed though)

Cons:

LINQ2QL limitations may be reached and forcing a downgrade to LINQ2Objects or going back to pure SQL solution depending on the case
careless writing of LINQ might generate awful queries (or many queries, if navigation properties loaded)

Plot width settings in ipython notebook

If you're not in an ipython notebook (like the OP), you can also just declare the size when you declare the figure:

width = 12
height = 12
plt.figure(figsize=(width, height))

How to ignore the first line of data when processing CSV data?

The new 'pandas' package might be more relevant than 'csv'. The code below will read a CSV file, by default interpreting the first line as the column header and find the minimum across columns.

import pandas as pd

data = pd.read_csv('all16.csv')
data.min()

How to get CRON to call in the correct PATHs

If you don't want to have to make the same edits in various places, then roughly do this:

* * * * * . /home/username/.bashrc && yourcommand all of your args

The . space and then the path to .bashrc and the && command are the magic there to get your environment changes into the running bash shell. Too, if you really want the shell to be bash, it is a good idea to have a line in your crontab:

SHELL=/bin/bash

Hope it helps someone!

number of values in a list greater than a certain number

I'll add a map and filter version because why not.

sum(map(lambda x:x>5, j))
sum(1 for _ in filter(lambda x:x>5, j))

Why javascript getTime() is not a function?

To use this function/method,you need an instance of the class Date .

This method is always used in conjunction with a Date object.

See the code below :

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

Link : http://www.w3schools.com/jsref/jsref_getTime.asp

How do I use cx_freeze?

You can change the setup.py code to this:

    from cx_freeze import setup, Executable
    setup( name = "foo",
           version = "1.1",
           description = "Description of the app here.",
           executables = [Executable("foo.py")]
         )

I am sure it will work. I have tried it on both windows 7 as well as ubuntu 12.04

jQuery/JavaScript to replace broken images

I believe this is what you're after: jQuery.Preload

Here's the example code from the demo, you specify the loading and not found images and you're all set:

jQuery('#images img').preload({
  placeholder:'placeholder.jpg',
  notFound:'notfound.jpg'
});

How to use refs in React with Typescript

To use the callback style (https://facebook.github.io/react/docs/refs-and-the-dom.html) as recommended on React's documentation you can add a definition for a property on the class:

export class Foo extends React.Component<{}, {}> {
// You don't need to use 'references' as the name
references: {
    // If you are using other components be more specific than HTMLInputElement
    myRef: HTMLInputElement;
} = {
    myRef: null
}
...
 myFunction() {
    // Use like this
    this.references.myRef.focus();
}
...
render() {
    return(<input ref={(i: any) => { this.references.myRef = i; }}/>)
}

Docker remove <none> TAG images

The below command is working for me. this is just simple grep "" images and get the docker image id and removed all the images. Simple single command as it has to.

docker rmi $(docker images |grep "<none>"| awk '{print $3}')

ValueError: could not convert string to float: id

My error was very simple: the text file containing the data had some space (so not visible) character on the last line.

As an output of grep, I had 45 instead of just 45.

Selected tab's color in Bottom Navigation View

Instead of creating selector, Best way to create a style.

<style name="AppTheme.BottomBar">
    <item name="colorPrimary">@color/colorAccent</item> 
</style>

and to change the text size, selected or non selected.

<dimen name="design_bottom_navigation_text_size" tools:override="true">11sp</dimen>
<dimen name="design_bottom_navigation_active_text_size" tools:override="true">12sp</dimen>

Enjoy Android!

C# LINQ find duplicates in List

Another way is using HashSet:

var hash = new HashSet<int>();
var duplicates = list.Where(i => !hash.Add(i));

If you want unique values in your duplicates list:

var myhash = new HashSet<int>();
var mylist = new List<int>(){1,1,2,2,3,3,3,4,4,4};
var duplicates = mylist.Where(item => !myhash.Add(item)).Distinct().ToList();

Here is the same solution as a generic extension method:

public static class Extensions
{
  public static IEnumerable<TSource> GetDuplicates<TSource, TKey>(this IEnumerable<TSource> source, Func<TSource, TKey> selector, IEqualityComparer<TKey> comparer)
  {
    var hash = new HashSet<TKey>(comparer);
    return source.Where(item => !hash.Add(selector(item))).ToList();
  }

  public static IEnumerable<TSource> GetDuplicates<TSource>(this IEnumerable<TSource> source, IEqualityComparer<TSource> comparer)
  {
    return source.GetDuplicates(x => x, comparer);      
  }

  public static IEnumerable<TSource> GetDuplicates<TSource, TKey>(this IEnumerable<TSource> source, Func<TSource, TKey> selector)
  {
    return source.GetDuplicates(selector, null);
  }

  public static IEnumerable<TSource> GetDuplicates<TSource>(this IEnumerable<TSource> source)
  {
    return source.GetDuplicates(x => x, null);
  }
}

Start ssh-agent on login

On Arch Linux, the following works really great (should work on all systemd-based distros):

Create a systemd user service, by putting the following to ~/.config/systemd/user/ssh-agent.service:

[Unit]
Description=SSH key agent

[Service]
Type=simple
Environment=SSH_AUTH_SOCK=%t/ssh-agent.socket
ExecStart=/usr/bin/ssh-agent -D -a $SSH_AUTH_SOCK

[Install]
WantedBy=default.target

Setup shell to have an environment variable for the socket (.bash_profile, .zshrc, ...):

export SSH_AUTH_SOCK="$XDG_RUNTIME_DIR/ssh-agent.socket"

Enable the service, so it'll be started automatically on login, and start it:

systemctl --user enable ssh-agent
systemctl --user start ssh-agent

Add the following configuration setting to your local ssh config file ~/.ssh/config (this works since SSH 7.2):

AddKeysToAgent  yes

This will instruct the ssh client to always add the key to a running agent, so there's no need to ssh-add it beforehand.

#ifdef replacement in the Swift language

In Swift projects created with Xcode Version 9.4.1, Swift 4.1

#if DEBUG
#endif

works by default because in the Preprocessor Macros DEBUG=1 has already been set by Xcode.

So you can use #if DEBUG "out of box".

By the way, how to use the condition compilation blocks in general is written in Apple's book The Swift Programming Language 4.1 (the section Compiler Control Statements) and how to write the compile flags and what is counterpart of the C macros in Swift is written in another Apple's book Using Swift with Cocoa and Objective C (in the section Preprocessor Directives)

Hope in future Apple will write the more detailed contents and the indexes for their books.

Simulate a button click in Jest

I needed to do a little bit of testing myself of a button component. These tests work for me ;-)

import { shallow } from "enzyme";
import * as React from "react";
import Button from "../button.component";

describe("Button Component Tests", () => {
    it("Renders correctly in DOM", () => {
        shallow(
            <Button text="Test" />
        );
    });
    it("Expects to find button HTML element in the DOM", () => {
        const wrapper = shallow(<Button text="test"/>)
        expect(wrapper.find('button')).toHaveLength(1);
    });

    it("Expects to find button HTML element with className test in the DOM", () => {
        const wrapper = shallow(<Button className="test" text="test"/>)
        expect(wrapper.find('button.test')).toHaveLength(1);
    });

    it("Expects to run onClick function when button is pressed in the DOM", () => {
        const mockCallBackClick = jest.fn();
        const wrapper = shallow(<Button onClick={mockCallBackClick} className="test" text="test"/>);
        wrapper.find('button').simulate('click');
        expect(mockCallBackClick.mock.calls.length).toEqual(1);
    });
});

In Python, how do I convert all of the items in a list to floats?

you can use numpy to avoid looping:

import numpy as np
list(np.array(my_list).astype(float)

Convert a SQL query result table to an HTML table for email

based on JustinStolle code (thank you), I wanted a solution that could be generic without having to specify the column names.

This sample is using the data of a temp table but of course it can be adjusted as required.

Here is what I got:

DECLARE @htmlTH VARCHAR(MAX) = '',
        @htmlTD VARCHAR(MAX)

--get header, columns name
SELECT @htmlTH = @htmlTH + '<TH>' +  name + '</TH>' FROM tempdb.sys.columns WHERE object_id = OBJECT_ID('tempdb.dbo.#results')

--convert table to XML PATH, ELEMENTS XSINIL is used to include NULL values
SET @htmlTD = (SELECT * FROM #results FOR XML PATH('TR'), ELEMENTS XSINIL)

--convert the way ELEMENTS XSINIL display NULL to display word NULL
SET @htmlTD = REPLACE(@htmlTD, ' xsi:nil="true"/>', '>NULL</TD>')
SET @htmlTD = REPLACE(@htmlTD, '<TR xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">', '<TR>')

--FOR XML PATH will set tags for each column name, <columnName1>abc</columnName1><columnName2>def</columnName2>
--this will replace all the column names with TD (html table data tag)
SELECT @htmlTD = REPLACE(REPLACE(@htmlTD, '<' + name + '>', '<TD>'), '</' + name + '>', '</TD>')
FROM tempdb.sys.columns WHERE object_id = OBJECT_ID('tempdb.dbo.#results')


SELECT '<TABLE cellpadding="2" cellspacing="2" border="1">'
     + '<TR>' + @htmlTH + '</TR>'
     + @htmlTD
     + '</TABLE>'

Binary Data in JSON String. Something better than Base64

I dig a little bit more (during implementation of base128), and expose that when we send characters which ascii codes are bigger than 128 then browser (chrome) in fact send TWO characters (bytes) instead one :(. The reason is that JSON by defaul use utf8 characters for which characters with ascii codes above 127 are coded by two bytes what was mention by chmike answer. I made test in this way: type in chrome url bar chrome://net-export/ , select "Include raw bytes", start capturing, send POST requests (using snippet at the bottom), stop capturing and save json file with raw requests data. Then we look inside that json file:

We can find our base64 request by finding string 4142434445464748494a4b4c4d4e this is hex coding of ABCDEFGHIJKLMN and we will see that "byte_count": 639 for it.
We can find our above127 request by finding string C2BCC2BDC380C381C382C383C384C385C386C387C388C389C38AC38B this are request-hex utf8 codes of characters ¼½ÀÁÂÃÄÅÆÇÈÉÊË (however the ascii hex codes of this characters are c1c2c3c4c5c6c7c8c9cacbcccdce). The "byte_count": 703 so it is 64bytes longer than base64 request because characters with ascii codes above 127 are code by 2 bytes in request :(

So in fact we don't have profit with sending characters with codes >127 :( . For base64 strings we not observe such negative behaviour (probably for base85 too - I don check it) - however may be some solution for this problem will be sending data in binary part of POST multipart/form-data described in Ælex answer (however usually in this case we don't need to use any base coding at all...).

The alternative approach may rely on mapping two bytes data portion into one valid utf8 character by code it using something like base65280 / base65k but probably it would be less effective than base64 due to utf8 specification ...

_x000D_

function postBase64() {_x000D_
  let formData = new FormData();_x000D_
  let req = new XMLHttpRequest();_x000D_
_x000D_
  formData.append("base64ch", "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/");_x000D_
  req.open("POST", '/testBase64ch');_x000D_
  req.send(formData);_x000D_
}_x000D_
_x000D_
_x000D_
function postAbove127() {_x000D_
  let formData = new FormData();_x000D_
  let req = new XMLHttpRequest();_x000D_
_x000D_
  formData.append("above127", "¼½ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüý");_x000D_
  req.open("POST", '/testAbove127');_x000D_
  req.send(formData);_x000D_
}

_x000D_

<button onclick=postBase64()>POST base64 chars</button>_x000D_
<button onclick=postAbove127()>POST chars with codes>127</button>

_x000D_

Deny all, allow only one IP through htaccess

ErrorDocument 403 /maintenance.html
Order Allow,Deny
Allow from #:#:#:#:#:#

For me, this seems to work (Using IPv6 rather than IPv4) I don't know if this is different for some websites but for mine this works.

log4j logging hierarchy order

OFF
FATAL
ERROR
WARN
INFO
DEBUG
TRACE
ALL

SQL conditional SELECT

This is a psuedo way of doing it

IF (selectField1 = true) 
SELECT Field1 FROM Table
ELSE
SELECT Field2 FROM Table

Should I use string.isEmpty() or "".equals(string)?

One thing you might want to consider besides the other issues mentioned is that isEmpty() was introduced in 1.6, so if you use it you won't be able to run the code on Java 1.5 or below.

Importing PNG files into Numpy?

If you are loading images, you are likely going to be working with one or both of matplotlib and opencv to manipulate and view the images.

For this reason, I tend to use their image readers and append those to lists, from which I make a NumPy array.

import os
import matplotlib.pyplot as plt
import cv2
import numpy as np

# Get the file paths
im_files = os.listdir('path/to/files/')

# imagine we only want to load PNG files (or JPEG or whatever...)
EXTENSION = '.png'

# Load using matplotlib
images_plt = [plt.imread(f) for f in im_files if f.endswith(EXTENSION)]
# convert your lists into a numpy array of size (N, H, W, C)
images = np.array(images_plt)

# Load using opencv
images_cv = [cv2.imread(f) for f in im_files if f.endswith(EXTENSION)]
# convert your lists into a numpy array of size (N, C, H, W)
images = np.array(images_cv)

The only difference to be aware of is the following:

opencv loads channels first
matplotlib loads channels last.

So a single image that is 256*256 in size would produce matrices of size (3, 256, 256) with opencv and (256, 256, 3) using matplotlib.

Why should I prefer to use member initialization lists?

Initialization of base class

One important reason for using constructor initializer list which is not mentioned in answers here is initialization of base class.

As per the order of construction, base class should be constructed before child class. Without constructor initializer list, this is possible if your base class has default constructor which will be called just before entering the constructor of child class.

But, if your base class has only parameterized constructor, then you must use constructor initializer list to ensure that your base class is initialized before child class.

Initialization of Subobjects which only have parameterized constructors
Efficiency

Using constructor initializer list, you initialize your data members to exact state which you need in your code rather than first initializing them to their default state & then changing their state to the one you need in your code.

Initializing non-static const data members

If non-static const data members in your class have default constructors & you don't use constructor initializer list, you won't be able to initialize them to intended state as they will be initialized to their default state.

Initialization of reference data members

Reference data members must be intialized when compiler enters constructor as references can't be just declared & initialized later. This is possible only with constructor initializer list.

'dispatch' is not a function when argument to mapToDispatchToProps() in Redux

i am using like this.. its easy to understand first argument is mapStateToProps and second argument is mapDispatchToProps in the end connect with function/class.

const mapStateToProps = (state) => {
  return {
    todos: getVisibleTodos(state.todos, state.visibilityFilter)
  }
}

const mapDispatchToProps = (dispatch) => {
  return {
    onTodoClick: (id) => {
      dispatch(toggleTodo(id))
    }
  }
}

export default connect(mapStateToProps,mapDispatchToProps)(TodoList);

jquery animate background position

jQuery's animate function is not exclusively usable for directly animating properties of DOM-objects. You can also tween variables and use the step function to get the variables for every step of the tween.

For example, to animate a background-position from background-position(0px 0px) to background-position(100px 500px) you can do this:

$({temporary_x: 0, temporary_y: 0}).animate({temporary_x: 100, temporary_y: 500}, {
    duration: 1000,
    step: function() {
        var position = Math.round(this.temporary_x) + "px " + Math.round(this.temporary_y) + "px";
        $("#your_div").css("background-position",  position);
    }
});

Just make sure to not forget the this. inside the step function.

What database does Google use?

It's something they've built themselves - it's called Bigtable.

http://en.wikipedia.org/wiki/BigTable

There is a paper by Google on the database:

http://research.google.com/archive/bigtable.html

Finding Number of Cores in Java

If you want to dubbel check the amount of cores you have on your machine to the number your java program is giving you.

In Linux terminal: lscpu

In Windows terminal (cmd): echo %NUMBER_OF_PROCESSORS%

In Mac terminal: sysctl -n hw.ncpu

VBA: Conditional - Is Nothing

Just becuase your class object has no variables does not mean that it is nothing. Declaring and object and creating an object are two different things. Look and see if you are setting/creating the object.

Take for instance the dictionary object - just because it contains no variables does not mean it has not been created.

Sub test()

Dim dict As Object
Set dict = CreateObject("scripting.dictionary")

If Not dict Is Nothing Then
    MsgBox "Dict is something!"  '<--- This shows
Else
    MsgBox "Dict is nothing!"
End If

End Sub

However if you declare an object but never create it, it's nothing.

Sub test()

Dim temp As Object

If Not temp Is Nothing Then
    MsgBox "Temp is something!"
Else
    MsgBox "Temp is nothing!" '<---- This shows
End If

End Sub

When do I use the PHP constant "PHP_EOL"?

Handy with error_log() if you're outputting multiple lines.

I've found a lot of debug statements look weird on my windows install since the developers have assumed unix endings when breaking up strings.

CSS3 :unchecked pseudo-class

The way I handled this was switching the className of a label based on a condition. This way you only need one label and you can have different classes for different states... Hope that helps!

NodeJS accessing file with relative path

You can use the path module to join the path of the directory in which helper1.js lives to the relative path of foobar.json. This will give you the absolute path to foobar.json.

var fs = require('fs');
var path = require('path');

var jsonPath = path.join(__dirname, '..', 'config', 'dev', 'foobar.json');
var jsonString = fs.readFileSync(jsonPath, 'utf8');

This should work on Linux, OSX, and Windows assuming a UTF8 encoding.

Escape invalid XML characters in C#

string XMLWriteStringWithoutIllegalCharacters(string UnfilteredString)
{
    if (UnfilteredString == null)
        return string.Empty;

    return XmlConvert.EncodeName(UnfilteredString);
}

string XMLReadStringWithoutIllegalCharacters(string FilteredString)
{
    if (UnfilteredString == null)
        return string.Empty;

    return XmlConvert.DecodeName(UnfilteredString);
}

This simple method replace the invalid characters with the same value but accepted in the XML context.

To write string use XMLWriteStringWithoutIllegalCharacters(string UnfilteredString).
To read string use XMLReadStringWithoutIllegalCharacters(string FilteredString).

Is there a cross-domain iframe height auto-resizer that works?

You have three alternatives:

1. Use iFrame-resizer

This is a simple library for keeping iFrames sized to their content. It uses the PostMessage and MutationObserver APIs, with fall backs for IE8-10. It also has options for the content page to request the containing iFrame is a certain size and can also close the iFrame when your done with it.

https://github.com/davidjbradshaw/iframe-resizer

2. Use Easy XDM (PostMessage + Flash combo)

Easy XDM uses a collection of tricks for enabling cross-domain communication between different windows in a number of browsers, and there are examples for using it for iframe resizing:

http://easyxdm.net/wp/2010/03/17/resize-iframe-based-on-content/

http://kinsey.no/blog/index.php/2010/02/19/resizing-iframes-using-easyxdm/

Easy XDM works by using PostMessage on modern browsers and a Flash based solution as fallback for older browsers.

See also this thread on Stackoverflow (there are also others, this is a commonly asked question). Also, Facebook would seem to use a similar approach.

3. Communicate via a server

Another option would be to send the iframe height to your server and then poll from that server from the parent web page with JSONP (or use a long poll if possible).

Multi column forms with fieldsets

There are a couple of things that need to be adjusted in your layout:

You are nesting col elements within form-group elements. This should be the other way around (the form-group should be within the col-sm-xx element).
You should always use a row div for each new "row" in your design. In your case, you would need at least 5 rows (Username, Password and co, Title/First/Last name, email, Language). Otherwise, your problematic .col-sm-12 is still on the same row with the above 3 .col-sm-4 resulting in a total of columns greater than 12, and causing the overlap problem.

Here is a fixed demo.

And an excerpt of what the problematic section HTML should become:

<fieldset>
    <legend>Personal Information</legend>
    <div class='row'>
        <div class='col-sm-4'>    
            <div class='form-group'>
                <label for="user_title">Title</label>
                <input class="form-control" id="user_title" name="user[title]" size="30" type="text" />
            </div>
        </div>
        <div class='col-sm-4'>
            <div class='form-group'>
                <label for="user_firstname">First name</label>
                <input class="form-control" id="user_firstname" name="user[firstname]" required="true" size="30" type="text" />
            </div>
        </div>
        <div class='col-sm-4'>
            <div class='form-group'>
                <label for="user_lastname">Last name</label>
                <input class="form-control" id="user_lastname" name="user[lastname]" required="true" size="30" type="text" />
            </div>
        </div>
    </div>
    <div class='row'>
        <div class='col-sm-12'>
            <div class='form-group'>

                <label for="user_email">Email</label>
                <input class="form-control required email" id="user_email" name="user[email]" required="true" size="30" type="text" />
            </div>
        </div>
    </div>
</fieldset>

How to iterate (keys, values) in JavaScript?

I think the fast and easy way is

Object.entries(event).forEach(k => {
    console.log("properties ... ", k[0], k[1]); });

just check the documentation https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/entries

JQuery post JSON object to a server

To send json to the server, you first have to create json

function sendData() {
    $.ajax({
        url: '/helloworld',
        type: 'POST',
        contentType: 'application/json',
        data: JSON.stringify({
            name:"Bob",
            ...
        }),
        dataType: 'json'
    });
}

This is how you would structure the ajax request to send the json as a post var.

function sendData() {
    $.ajax({
        url: '/helloworld',
        type: 'POST',
        data: { json: JSON.stringify({
            name:"Bob",
            ...
        })},
        dataType: 'json'
    });
}

The json will now be in the json post var.

Changing file permission in Python

os.chmod(path, 0444) is the Python command for changing file permissions in Python 2.x. For a combined Python 2 and Python 3 solution, change 0444 to 0o444.

You could always use Python to call the chmod command using subprocess. I think this will only work on Linux though.

import subprocess

subprocess.call(['chmod', '0444', 'path'])

Android Studio Image Asset Launcher Icon Background Color

These are the steps I took to make an image transparent:

1- I used an online website which makes the image transparent, there are a lot of them. For me, I use this https://www241.lunapic.com/editor/?action=transparent and sometimes this http://www.online-image-editor.com/help/transparency

2- In Android Studio (I'm using version 3.1.3), open Image Asset from app > res (right click) > New > Image Asset

3- In the Path, choose the location of the transparent image which you downloaded from the online website, and make the other options as shown, then Next, then Finish. The five different sizes of image mdpi(48×48), hdpi(72×72), xhdpi(96×96), xxhdpi(144×144), and xxxhdpi(192×192) will be created in the res/mipmap-density folders.

4- If you need sizes (dimensions) different from above, you can use this website http://nsimage.brosteins.com/ to upload your PNG image of biggest size that will be used in xxxhdpi. After uploading, you can download a zip file containing the five different sizes of image in the res/drawable-density folders.

finding the type of an element using jQuery

You can use .prop() with tagName as the name of the property that you want to get:

$("#elementId").prop('tagName');

What is the full path to the Packages folder for Sublime text 2 on Mac OS Lion

According to the documentation, in Sublime 2, the data directory should be on these locations:

Windows: %APPDATA%\Sublime Text 2
OS X: ~/Library/Application Support/Sublime Text 2
Linux: ~/.config/sublime-text-2

This information is available here: http://docs.sublimetext.info/en/sublime-text-2/basic_concepts.html#the-data-directory

For Sublime 3, the locations are the following:

Windows: %APPDATA%\Sublime Text 3
OS X: ~/Library/Application Support/Sublime Text 3
Linux: ~/.config/sublime-text-3

This information is available here:http://docs.sublimetext.info/en/sublime-text-3/basic_concepts.html#the-data-directory

How can I get my Android device country code without using GPS?

If you wish to get the country code without asking for any permission, you can choose a tricky way.

The method simply uses an API to get the country code, and there aren't any third-party libraries to depend on. We can create one for us.

Here I have used Google Cloud Functions to write an API and it is so effortless.

Step 1: Create a Google Cloud Account, and set up billing (the free tier is enough)

Step 2: Create a cloud function to get the geo location

Copy this basic function to the code editor of index.js:

const cors = require('cors')

function _geolocation(req, res) {
  const data = {
    country_code: req.headers["x-appengine-country"],
    region: req.headers["x-appengine-region"],
    city: req.headers["x-appengine-city"],
    cityLatLong: req.headers["x-appengine-citylatlong"],
    userIP: req.headers["x-appengine-user-ip"]
  }

  res.json(data)
};

exports.geolocation = (req, res) => {
  const corsHandler = cors({ origin: true })

  return corsHandler(req, res, function() {
    return _geolocation(req, res);
  });
};

Also we need to copy the package.json definition:

{
  "name": "gfc-geolocation",
  "version": "0.0.1",
  "dependencies": {
    "cors": "^2.8.4"
  }
}

Step 3: finish, and get the URL similar to: "https://us-central1-geolocation-mods-sdde.cloudfunctions.net/geolocation"

Step 4: parse the JSON response and get the country code

The response will look like:

{
   "country": "IN",
   "region": "kl",
   "city": "kochi",
   "cityLatLong": "9.9312,76.2673",
   "userIP": "xx.xx.xx.xx"
}

Thanks and credits go to the Medium article: Free IP-based Geolocation with Google Cloud Functions

how to set ulimit / file descriptor on docker container the image tag is phusion/baseimage-docker

The latest docker supports setting ulimits through the command line and the API. For instance, docker run takes --ulimit <type>=<soft>:<hard> and there can be as many of these as you like. So, for your nofile, an example would be --ulimit nofile=262144:262144

Why do I get permission denied when I try use "make" to install something?

The problem is frequently with 'secure' setup of mountpoints, such as /tmp

If they are mounted noexec (check with cat /etc/mtab and or sudo mount) then there is no permission to execute any binaries or build scripts from within the (temporary) folder.

E.g. to remount temporarily:

 sudo mount -o remount,exec /tmp

Or to change permanently, remove noexec in /etc/fstab

Calling a php function by onclick event

Use this html code it will surely help you

<input type="button" value="NEXT"  onclick="document.write('<?php //call a function here ex- 'fun();' ?>');" />

one limitation is that it is taking more time to run so wait for few seconds it will work

Python argparse command line flags without arguments

Adding a quick snippet to have it ready to execute:

Source: myparser.py

import argparse
parser = argparse.ArgumentParser(description="Flip a switch by setting a flag")
parser.add_argument('-w', action='store_true')

args = parser.parse_args()
print args.w

Usage:

python myparser.py -w
>> True

How can I do SELECT UNIQUE with LINQ?

var uniqueColors = (from dbo in database.MainTable 
                    where dbo.Property == true
                    select dbo.Color.Name).Distinct();

Why is  appearing in my HTML?

Before clear space (trim)

Then replace with RegEx .replace("/\xEF\xBB\xBF/", "")

I'm working on Javascript, I did with JavaScript.

SQL : BETWEEN vs <= and >=

They are identical: BETWEEN is a shorthand for the longer syntax in the question.

Use an alternative longer syntax where BETWEEN doesn't work e.g.

Select EventId,EventName from EventMaster
where EventDate >= '10/15/2009' and EventDate < '10/19/2009'

(Note < rather than <= in second condition.)

How to get length of a string using strlen function

Function strlen shows the number of character before \0 and using it for std::string may report wrong length.

strlen(str.c_str()); // It may return wrong length.

In C++, a string can contain \0 within the characters but C-style-zero-terminated strings can not but at the end. If the std::string has a \0 before the last character then strlen reports a length less than the actual length.

Try to use .length() or .size(), I prefer second one since another standard containers have it.

str.size()

Regular expression for 10 digit number without any special characters

Use this regular expression to match ten digits only:

@"^\d{10}$"

To find a sequence of ten consecutive digits anywhere in a string, use:

@"\d{10}"

Note that this will also find the first 10 digits of an 11 digit number. To search anywhere in the string for exactly 10 consecutive digits and not more you can use negative lookarounds:

@"(?<!\d)\d{10}(?!\d)"

How to include another XHTML in XHTML using JSF 2.0 Facelets?

Included page:

<!-- opening and closing tags of included page -->
<ui:composition ...>
</ui:composition>

Including page:

<!--the inclusion line in the including page with the content-->
<ui:include src="yourFile.xhtml"/>

You start your included xhtml file with ui:composition as shown above.
You include that file with ui:include in the including xhtml file as also shown above.

C++ Error 'nullptr was not declared in this scope' in Eclipse IDE

I add the ",-std=c++0x" after "-c -fmessage-length=0",under Project Properties -> C/C++ Build -> Settings -> GCC C++ Compiler -> Miscellaneous. Dont't forget to add the comma "," as the seperator.

"unadd" a file to svn before commit

For Files - svn revert filename

For Folders - svn revert -R folder

How do I get java logging output to appear on a single line?

Similar to Tervor, But I like to change the property on runtime.

Note that this need to be set before the first SimpleFormatter is created - as was written in the comments.

    System.setProperty("java.util.logging.SimpleFormatter.format", 
            "%1$tF %1$tT %4$s %2$s %5$s%6$s%n");

How can I get the application's path in a .NET console application?

I have used this code and get the solution.

AppDomain.CurrentDomain.BaseDirectory

How to change the default docker registry from docker.io to my private registry?

if you are using the fedora distro, you can change the file

/etc/containers/registries.conf

Adding domain docker.io

Android Transparent TextView?

Hi Please try with the below color code as textview's background.

android:background="#20535252"

Get first and last day of month using threeten, LocalDate

Just use withDayOfMonth, and lengthOfMonth():

LocalDate initial = LocalDate.of(2014, 2, 13);
LocalDate start = initial.withDayOfMonth(1);
LocalDate end = initial.withDayOfMonth(initial.lengthOfMonth());

How to make a variable accessible outside a function?

$.getJSON is an asynchronous request, meaning the code will continue to run even though the request is not yet done. You should trigger the second request when the first one is done, one of the choices you seen already in ComFreek's answer.

Alternatively you could use jQuery's $.when/.then(), similar to this:

var input = "netuetamundis";  var sID;  $(document).ready(function () {     $.when($.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.1/summoner/by-name/" + input + "?api_key=API_KEY_HERE", function () {         obj = name;         sID = obj.id;         console.log(sID);     })).then(function () {         $.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.2/stats/by-summoner/" + sID + "/summary?api_key=API_KEY_HERE", function (stats) {             console.log(stats);         });     }); });

This would be more open for future modification and separates out the responsibility for the first call to know about the second call.

The first call can simply complete and do it's own thing not having to be aware of any other logic you may want to add, leaving the coupling of the logic separated.

how can I see what ports mongo is listening on from mongo shell?

How do I trim() a string in angularjs?

use trim() method of javascript after all angularjs is also a javascript framework and it is not necessary to put $ to apply trim()

for example

var x="hello world";
x=x.trim()

FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory in ionic 3

For a non-angular general answer for those who land on this question from Google:

Every time you face this error its probably because of a memory leak or difference between how Node <= 10 and Node > 10 manage memory. Usually just increasing the memory allocated to Node will allow your program to run but may not actually solve the real problem and the memory used by the node process could still exceed the new memory you allocate. I'd advise profiling memory usage in your node process when it starts running or updating to node > 10.

I had a memory leak. Here is a great article on debugging memory leaks in node.

That said, to increase the memory, in the terminal where you run your Node process:

export NODE_OPTIONS="--max-old-space-size=8192"

where values of max-old-space-size can be: [2048, 4096, 8192, 16384] etc

[UPDATE] More examples for further clarity:

export NODE_OPTIONS="--max-old-space-size=5120" #increase to 5gb
export NODE_OPTIONS="--max-old-space-size=6144" #increase to 6gb
export NODE_OPTIONS="--max-old-space-size=7168" #increase to 7gb
export NODE_OPTIONS="--max-old-space-size=8192" #increase to 8gb

# and so on...

# formula:
export NODE_OPTIONS="--max-old-space-size=(X * 1024)" #increase to Xgb

# Note: it doesn't have to be multiples of 1024. 
# max-old-space-size can be any number of memory megabytes(MB) you have available.

Generate a dummy-variable

The ifelse function is best for simple logic like this.

> x <- seq(1950, 1960, 1)

    ifelse(x == 1957, 1, 0)
    ifelse(x <= 1957, 1, 0)

>  [1] 0 0 0 0 0 0 0 1 0 0 0
>  [1] 1 1 1 1 1 1 1 1 0 0 0

Also, if you want it to return character data then you can do so.

> x <- seq(1950, 1960, 1)

    ifelse(x == 1957, "foo", "bar")
    ifelse(x <= 1957, "foo", "bar")

>  [1] "bar" "bar" "bar" "bar" "bar" "bar" "bar" "foo" "bar" "bar" "bar"
>  [1] "foo" "foo" "foo" "foo" "foo" "foo" "foo" "foo" "bar" "bar" "bar"

Categorical variables with nesting...

> x <- seq(1950, 1960, 1)

    ifelse(x == 1957, "foo", ifelse(x == 1958, "bar","baz"))

>  [1] "baz" "baz" "baz" "baz" "baz" "baz" "baz" "foo" "bar" "baz" "baz"

This is the most straightforward option.

ERROR 1049 (42000): Unknown database 'mydatabasename'

If dump file contains:

CREATE DATABASE mydatabasename;
USE mydatabasename;

You may just use in CLI:

mysql -uroot –pmypassword < mydatabase.sql

It works.

How to resolve ambiguous column names when retrieving results?

If you don't feel like aliassing you can also just prefix the tablenames.

This way you can better automate generation of your queries. Also, it's a best-practice to not use select * (it is obviously slower than just selecting the fields you need Furthermore, only explicitly name the fields you want to have.

SELECT
    news.id, news.title, news.author, news.posted, 
    users.id, users.name, users.registered 
FROM 
    news 
LEFT JOIN 
    users 
ON 
    news.user = user.id

Android: where are downloaded files saved?

In my experience all the files which i have downloaded from internet,gmail are stored in

/sdcard/download

on ics

/sdcard/Download

You can access it using

Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);

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

This happened to me because a Nuget package uninstaller blew away all the attributes on the <Application> element in App.xaml. This included the x:Class attribute, which specifies the application class name. So the partial class containing the InitializeComponent() method was never generated.

I fixed the problem by reverting App.xaml to the source-controlled copy.

Convert ASCII TO UTF-8 Encoding

Use utf8_encode()

Man page can be found here http://php.net/manual/en/function.utf8-encode.php

Also read this article from Joel on Software. It provides an excellent explanation if what Unicode is and how it works. http://www.joelonsoftware.com/articles/Unicode.html

How to get some values from a JSON string in C#?

my string

var obj = {"Status":0,"Data":{"guid":"","invitationGuid":"","entityGuid":"387E22AD69-4910-430C-AC16-8044EE4A6B24443545DD"},"Extension":null}

Following code to get guid:

var userObj = JObject.Parse(obj);
var userGuid = Convert.ToString(userObj["Data"]["guid"]);

Pointer-to-pointer dynamic two-dimensional array

this can be done this way

I have used Operator Overloading
Overloaded Assignment

Overloaded Copy Constructor

/*
 * Soumil Nitin SHah
 * Github: https://github.com/soumilshah1995
 */

#include <iostream>
using namespace std;
        class Matrix{

public:
    /*
     * Declare the Row and Column
     *
     */
    int r_size;
    int c_size;
    int **arr;

public:
    /*
     * Constructor and Destructor
     */

    Matrix(int r_size, int c_size):r_size{r_size},c_size{c_size}
    {
        arr = new int*[r_size];
        // This Creates a 2-D Pointers
        for (int i=0 ;i < r_size; i++)
        {
            arr[i] = new int[c_size];
        }

        // Initialize all the Vector to 0 initially
        for (int row=0; row<r_size; row ++)
        {
            for (int column=0; column < c_size; column ++)
            {
                arr[row][column] = 0;
            }
        }
        std::cout << "Constructor -- creating Array Size ::" << r_size << " " << c_size << endl;
    }

    ~Matrix()
    {
        std::cout << "Destructpr  -- Deleting  Array Size ::" << r_size <<" " << c_size << endl;

    }

    Matrix(const Matrix &source):Matrix(source.r_size, source.c_size)

    {
        for (int row=0; row<source.r_size; row ++)
        {
            for (int column=0; column < source.c_size; column ++)
            {
                arr[row][column] = source.arr[row][column];
            }
        }

        cout << "Copy Constructor " << endl;
    }


public:
    /*
     * Operator Overloading
     */

    friend std::ostream &operator<<(std::ostream &os, Matrix & rhs)
    {
        int rowCounter = 0;
        int columnCOUNTER = 0;
        int globalCounter = 0;

        for (int row =0; row < rhs.r_size; row ++)
        {
            for (int column=0; column < rhs.c_size ; column++)
            {
                globalCounter = globalCounter + 1;
            }
            rowCounter = rowCounter + 1;
        }


        os << "Total There are " << globalCounter << " Elements" << endl;
        os << "Array Elements are as follow -------" << endl;
        os << "\n";

        for (int row =0; row < rhs.r_size; row ++)
        {
            for (int column=0; column < rhs.c_size ; column++)
            {
                os << rhs.arr[row][column] << " ";
            }
        os <<"\n";
        }
        return os;
    }

    void operator()(int row, int column , int Data)
    {
        arr[row][column] = Data;
    }

    int &operator()(int row, int column)
    {
        return arr[row][column];
    }

    Matrix &operator=(Matrix &rhs)
            {
                cout << "Assingment Operator called " << endl;cout <<"\n";
                if(this == &rhs)
                {
                    return *this;
                } else
                    {
                    delete [] arr;

                        arr = new int*[r_size];
                        // This Creates a 2-D Pointers
                        for (int i=0 ;i < r_size; i++)
                        {
                            arr[i] = new int[c_size];
                        }

                        // Initialize all the Vector to 0 initially
                        for (int row=0; row<r_size; row ++)
                        {
                            for (int column=0; column < c_size; column ++)
                            {
                                arr[row][column] = rhs.arr[row][column];
                            }
                        }

                        return *this;
                    }

            }

};

            int main()
{

    Matrix m1(3,3);         // Initialize Matrix 3x3

    cout << m1;cout << "\n";

    m1(0,0,1);
    m1(0,1,2);
    m1(0,2,3);

    m1(1,0,4);
    m1(1,1,5);
    m1(1,2,6);

    m1(2,0,7);
    m1(2,1,8);
    m1(2,2,9);

    cout << m1;cout <<"\n";             // print Matrix
    cout << "Element at Position (1,2) : " << m1(1,2) << endl;

    Matrix m2(3,3);
    m2 = m1;
    cout << m2;cout <<"\n";

    print(m2);

    return 0;
}

PHP XML Extension: Not installed

I solved this issue with commands bellow:

$ sudo apt-get install php7.3-intl

$ sudo /etc/init.d/php7.3-fpm restart

These commands works for me in homestead with php7.3

Convert comma separated string of ints to int array

Let us assume that you will be reading the string from the console. Import System.Linq and try this one:

int[] input = Console.ReadLine()
            .Split(',', StringSplitOptions.RemoveEmptyEntries)
            .Select(int.Parse)
            .ToArray();

Android, Java: HTTP POST Request

to @BalusC answer I would add how to convert the response in a String:

HttpResponse response = client.execute(request);
HttpEntity entity = response.getEntity();
if (entity != null) {
    InputStream instream = entity.getContent();

    String result = RestClient.convertStreamToString(instream);
    Log.i("Read from server", result);
}

Here is an example of convertStramToString.

How do I get a human-readable file size in bytes abbreviation using .NET?

string[] suffixes = { "B", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB" };
int s = 0;
long size = fileInfo.Length;

while (size >= 1024)
{
    s++;
    size /= 1024;
}

string humanReadable = String.Format("{0} {1}", size, suffixes[s]);

Why an abstract class implementing an interface can miss the declaration/implementation of one of the interface's methods?

That's fine. To understand the above, you have to understand the nature of abstract classes first. They are similar to interfaces in that respect. This is what Oracle say about this here.

Abstract classes are similar to interfaces. You cannot instantiate them, and they may contain a mix of methods declared with or without an implementation.

So you have to think about what happens when an interface extends another interface. For example ...

//Filename: Sports.java
public interface Sports
{
   public void setHomeTeam(String name);
   public void setVisitingTeam(String name);
}

//Filename: Football.java
public interface Football extends Sports
{
   public void homeTeamScored(int points);
   public void visitingTeamScored(int points);
   public void endOfQuarter(int quarter);
}

... as you can see, this also compiles perfectly fine. Simply because, just like an abstract class, an interface can NOT be instantiated. So, it is not required to explicitly mention the methods from its "parent". However, ALL the parent method signatures DO implicitly become a part of the extending interface or implementing abstract class. So, once a proper class (one that can be instantiated) extends the above, it WILL be required to ensure that every single abstract method is implemented.

Hope that helps... and Allahu 'alam !

What is the difference between char * const and const char *?

To avoid confusion, always append the const qualifier.

int       *      mutable_pointer_to_mutable_int;
int const *      mutable_pointer_to_constant_int;
int       *const constant_pointer_to_mutable_int;
int const *const constant_pointer_to_constant_int;

Specify the from user when sending email using the mail command

Thanks to all example providers, some worked for some not. Below is another simple example format that worked for me.

echo "Sample body" | mail -s "Test email" [email protected] [email protected]

Are 2 dimensional Lists possible in c#?

You can also..do in this way,

List<List<Object>> Parent=new  List<List<Object>>();

List<Object> Child=new List<Object>();
child.Add(2349);
child.Add("Daft Punk");
child.Add("Human");
.
.
Parent.Add(child);

if you need another item(child), create a new instance of child,

Child=new List<Object>();
child.Add(2323);
child.Add("asds");
child.Add("jshds");
.
.
Parent.Add(child);

Installing NumPy and SciPy on 64-bit Windows (with Pip)

EDIT: The Numpy project now provides pre-compiled packages in the wheel format (package format enabling compiled code as binary in packages), so the installation is now as easy as with other packages.

Numpy (as also some other packages like Scipy, Pandas etc.) includes lot's of C-, Cython, and Fortran code that needs to be compiled properly, before you can use it. This is, btw, also the reason why these Python-packages provide such fast Linear Algebra.

To get precompiled packages for Windows, have a look at Gohlke's Unofficial Windows Binaries or use a distribution like Winpython (just works) or Anaconda (more complex) which provide an entire preconfigured environment with lots of packages from the scientific python stack.

How can I adjust DIV width to contents

Try width: max-content to adjust the width of the div by it's content.

<!DOCTYPE html>
<html>
<head>
<style>
div.ex1 {
  width:500px;
  margin: auto;
  border: 3px solid #73AD21;
}

div.ex2 {
  width: max-content;
  margin: auto;
  border: 3px solid #73AD21;
}
</style>
</head>
<body>

<div class="ex1">This div element has width 500px;</div>
<br>
<div class="ex2">Width by content size</div>

</body>
</html>

Rolling back bad changes with svn in Eclipse

In Eclipse Ganymede (Subclipse)

Select project/file that contains bad change, and from pop-up menu choose:

Team -> Show History

Revisions related to that project/file will be shown in History tab.

Find revision where "bad changes" were committed and from pop-up menu choose:

Revert Changes from Revision X

This will merge changes in file(s) modified within bad revision, with revision prior to bad revision.

There are two scenarios from here:

If you committed no changes for that file (bad revision is last revision for that file), it will simply remove changes made in bad revision. Those changes are merged to your working copy so you have to commit them.
If you committed some changes for that file (bad revision is not last revision for that file), you will have to manually resolve conflict. Let say that you have file readme.txt with, and bad revision number is 33. Also, you've made another commit for that file in revision 34. After you choose Revert Changes from Revision 33 you will have following in your working copy:

readme.txt.merge-left.r33 - bad revision

readme.txt.merge-right.r32 - before bad revision

readme.txt.working - working copy version (same as in r34 if you don't have any uncommitted changes)

Original readme.txt will be marked conflicted, and will contain merged version (where changes from bad revision are removed) with some markers (<<<<<<< .working etc). If you just want to remove changes from bad revision and keep changes made after that, then all you have to do is remove markers. Otherwise, you can copy contents from one of 3 files mentioned above to original file. Whatever you choose, when you are done, mark conflict resolved by

Team - Mark Resolved

Temporary files will be removed and your file will be marked changed. As in 1, you have to commit changes.

Note that this does not remove revision from revision history in svn repository. You simply made new revision where changes from bad revision are removed.

How do I install package.json dependencies in the current directory using npm

Just execute

sudo npm i --save

That's all

How do I override nested NPM dependency versions?

For those from 2018 and beyond, using npm version 5 or later: edit your package-lock.json: remove the library from "requires" section and add it under "dependencies".

For example, you want deglob package to use glob package version 3.2.11 instead of its current one. You open package-lock.json and see:

"deglob": {
  "version": "2.1.0",
  "resolved": "https://registry.npmjs.org/deglob/-/deglob-2.1.0.tgz",
  "integrity": "sha1-TUSr4W7zLHebSXK9FBqAMlApoUo=",
  "requires": {
    "find-root": "1.1.0",
    "glob": "7.1.2",
    "ignore": "3.3.5",
    "pkg-config": "1.1.1",
    "run-parallel": "1.1.6",
    "uniq": "1.0.1"
  }
},

Remove "glob": "7.1.2", from "requires", add "dependencies" with proper version:

"deglob": {
  "version": "2.1.0",
  "resolved": "https://registry.npmjs.org/deglob/-/deglob-2.1.0.tgz",
  "integrity": "sha1-TUSr4W7zLHebSXK9FBqAMlApoUo=",
  "requires": {
    "find-root": "1.1.0",
    "ignore": "3.3.5",
    "pkg-config": "1.1.1",
    "run-parallel": "1.1.6",
    "uniq": "1.0.1"
  },
  "dependencies": {
    "glob": {
      "version": "3.2.11"
    }
  }
},

Now remove your node_modules folder, run npm install and it will add missing parts to the "dependencies" section.

Testing if value is a function

A simple check like this will let you know if it exists/defined:

if (this.onsubmit)
{
  // do stuff;
}

How to get HTTP response code for a URL in Java?

Efficient way to get data(With uneven payload) by scanner.

public static String getResponseFromHttpUrl(URL url) throws IOException {
    HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
    try {
        InputStream in = urlConnection.getInputStream();

        Scanner scanner = new Scanner(in);
        scanner.useDelimiter("\\A");  // Put entire content to next token string, Converts utf8 to 16, Handles buffering for different width packets

        boolean hasInput = scanner.hasNext();
        if (hasInput) {
            return scanner.next();
        } else {
            return null;
        }
    } finally {
        urlConnection.disconnect();
    }
}

Git - How to close commit editor?

Had troubles as well. On Linux I used Ctrl+X (and Y to confirm) and then I was back on the shell ready to pull/push.

On Windows GIT Bash Ctrl+X would do nothing and found out it works quite like vi/vim. Press i to enter inline insert mode. Type the description at the very top, press esc to exit insert mode, then type :x! (now the cursor is at the bottom) and hit enter to save and exit.

If typing :q! instead, will exit the editor without saving (and commit will be aborted)

How does bitshifting work in Java?

You can't write binary literals like 00101011 in Java so you can write it in hexadecimal instead:

byte x = 0x2b;

To calculate the result of x >> 2 you can then just write exactly that and print the result.

System.out.println(x >> 2);

SQLAlchemy equivalent to SQL "LIKE" statement

If you use native sql, you can refer to my code, otherwise just ignore my answer.

SELECT * FROM table WHERE tags LIKE "%banana%";

from sqlalchemy import text

bar_tags = "banana"

# '%' attention to spaces
query_sql = """SELECT * FROM table WHERE tags LIKE '%' :bar_tags '%'"""

# db is sqlalchemy session object
tags_res_list = db.execute(text(query_sql), {"bar_tags": bar_tags}).fetchall()

Razor-based view doesn't see referenced assemblies

In ASP.NET Core MVC the solution is to add a using in _ViewImports.cshtml, instead of putting it web.config in the View folder when working with ASP.NET MVC 5.

_ViewImports.cshtml

@using mySolution
@using mySolution.ViewModels // <-- Add this, and place your ViewModel (e.g. LoginViewModel) in here.
@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers

View

@model LoginViewModel // Add to _ViewImports to make this line work
<div>This is the View for the login screen.</div>

if A vs if A is not None:

python >= 2.6,

if we write such as

if A:

will generate warning as,

FutureWarning: The behavior of this method will change in future versions. Use specific 'len(elem)' or 'elem is not None' test instead.

So we can use

if A is not None:

#1273 - Unknown collation: 'utf8mb4_unicode_ci' cPanel

Seems like your host does not provide a MySQL-version which is capable to run tables with utf8mb4 collation.

The WordPress tables were changed to utf8mb4 with Version 4.2 (released on April, 23rd 2015) to support Emojis, but you need MySQL 5.5.3 to use it. 5.5.3. is from March 2010, so it should normally be widely available. Cna you check if your hoster provides that version?

If not, and an upgrade is not possible, you might have to look out for another hoster to run the latest WordPress versions (and you should always do that for security reasons).

How do I disable Git Credential Manager for Windows?

I had had that problem, and I've only removed the git-credential-manager.exe file from:

C:\Program Files\Git\mingw64\libexec\git-core

How to validate Google reCAPTCHA v3 on server side?

this is solution

index.html

<html>
  <head>
    <title>Google recapcha demo - Codeforgeek</title>
    <script src='https://www.google.com/recaptcha/api.js'></script>
  </head>
  <body>
    <h1>Google reCAPTHA Demo</h1>
    <form id="comment_form" action="form.php" method="post">
      <input type="email" placeholder="Type your email" size="40"><br><br>
      <textarea name="comment" rows="8" cols="39"></textarea><br><br>
      <input type="submit" name="submit" value="Post comment"><br><br>
      <div class="g-recaptcha" data-sitekey="=== Your site key ==="></div>
    </form>
  </body>
</html>

verify.php

<?php
    $email; $comment; $captcha;

    if(isset($_POST['email']))
        $email=$_POST['email'];
    if(isset($_POST['comment']))
        $comment=$_POST['comment'];
    if(isset($_POST['g-recaptcha-response']))
        $captcha=$_POST['g-recaptcha-response'];

    if(!$captcha){
        echo '<h2>Please check the the captcha form.</h2>';
        exit;
    }

    $response = json_decode(file_get_contents("https://www.google.com/recaptcha/api/siteverify?secret=YOUR SECRET KEY&response=".$captcha."&remoteip=".$_SERVER['REMOTE_ADDR']), true);
    if($response['success'] == false)
    {
        echo '<h2>You are spammer ! Get the @$%K out</h2>';
    }
    else
    {
        echo '<h2>Thanks for posting comment.</h2>';
    }
?>

http://codeforgeek.com/2014/12/google-recaptcha-tutorial/

How to connect from windows command prompt to mysql command line

First jump to the mysql bin directory. You have two ways to connect

1) mysql -u root -p1234 (without space for password flag) 2) mysql -u root -p and enter the password when it is asking

Running AngularJS initialization code when view is loaded

I use the following template in my projects:

angular.module("AppName.moduleName", [])

/**
 * @ngdoc controller
 * @name  AppName.moduleName:ControllerNameController
 * @description Describe what the controller is responsible for.
 **/
    .controller("ControllerNameController", function (dependencies) {

        /* type */ $scope.modelName = null;
        /* type */ $scope.modelName.modelProperty1 = null;
        /* type */ $scope.modelName.modelPropertyX = null;

        /* type */ var privateVariable1 = null;
        /* type */ var privateVariableX = null;

        (function init() {
            // load data, init scope, etc.
        })();

        $scope.modelName.publicFunction1 = function () /* -> type  */ {
            // ...
        };

        $scope.modelName.publicFunctionX = function () /* -> type  */ {
            // ...
        };

        function privateFunction1() /* -> type  */ {
            // ...
        }

        function privateFunctionX() /* -> type  */ {
            // ...
        }

    });

Display Adobe pdf inside a div

may be you can do by using AJAX or jquery...
just send that file url on one page and then open like normally open pdf file in that page and use ajax.

1)so as soon as user will click on the button. then u call that function in which u above tast. So by this way there will be only one page and by that you can show as many pdf without refreshing page.

2) if u don't have many pdf and if u don't know then just upload that file on google docs and then just put the share link file....and then just use ajax or jquery.

i prefer jquery if u don't have use AJAX.

How can I set a custom date time format in Oracle SQL Developer?

I stumbled on this post while trying to change the display format for dates in sql-developer. Just wanted to add to this what I found out:

To Change the default display format, I would use the steps provided by ousoo i.e Tools > Preferences > ...
But a lot of times, I just want to retain the DEFAULT_FORMAT while modifying the format only during a bunch of related queries. That's when I would change the format of the session with the following:

alter SESSION set NLS_DATE_FORMAT = 'my_required_date_format'

Eg:

   alter SESSION set NLS_DATE_FORMAT = 'DD-MM-YYYY HH24:MI:SS'

Search all of Git history for a string?

Git can search diffs with the -S option (it's called pickaxe in the docs)

git log -S password

This will find any commit that added or removed the string password. Here a few options:

-p: will show the diffs. If you provide a file (-p file), it will generate a patch for you.
-G: looks for differences whose added or removed line matches the given regexp, as opposed to -S, which "looks for differences that introduce or remove an instance of string".
--all: searches over all branches and tags; alternatively, use --branches[=<pattern>] or --tags[=<pattern>]

Programs & Examples On #Spamassassin

What does "Failure [INSTALL_FAILED_OLDER_SDK]" mean in Android Studio?

JSONDecodeError: Expecting value: line 1 column 1 (char 0)

Send POST data on redirect with JavaScript/jQuery?

Unable to launch the IIS Express Web server

test attribute in JSTL <c:if> tag

Automatically create requirements.txt

Python Variable Declaration

What is the best Java QR code generator library?

How do I replace a character at a particular index in JavaScript?

How can I set the default timezone in node.js?

How to define relative paths in Visual Studio Project?

Corrupt jar file

Remove a parameter to the URL with JavaScript

how to delete the content of text file without deleting itself

Single Form Hide on Startup

make div's height expand with its content

connecting to mysql server on another PC in LAN

Why is there no xrange function in Python3?

Maven artifact and groupId naming

Can I dispatch an action in reducer?

php.ini: which one?

Handle ModelState Validation in ASP.NET Web API

How to write loop in a Makefile?

2D cross-platform game engine for Android and iOS?

Android: show/hide status bar/power bar

correct configuration for nginx to localhost?

How does DISTINCT work when using JPA and Hibernate

location.host vs location.hostname and cross-browser compatibility?

Is there a Google Voice API?

Read lines from a text file but skip the first two lines

Copy Files from Windows to the Ubuntu Subsystem

Subdomain on different host

How can I convert a string to a float in mysql?

Scanner method to get a char

How to get 0-padded binary representation of an integer in java?

How to set the java.library.path from Eclipse

Apache 13 permission denied in user's home directory

What is stdClass in PHP?

stdClass is not an anonymous class or anonymous object

Is there any simple way to convert .xls file to .csv file? (Excel)

Change url query string value using jQuery

Pandas left outer join multiple dataframes on multiple columns

builtins.TypeError: must be str, not bytes

how to convert .java file to a .class file

Jquery: how to sleep or delay?

How to resolve this System.IO.FileNotFoundException

How do I create a unique ID in Java?

"message failed to fetch from registry" while trying to install any module

Pandas read_sql with parameters

How to make a HTTP request using Ruby on Rails?

Database cluster and load balancing

Windows batch script to move files

What techniques can be used to define a class in JavaScript, and what are their trade-offs?

Check if a Python list item contains a string inside another string

Pandas : compute mean or std (standard deviation) over entire dataframe

private final static attribute vs private final attribute

Do Swift-based applications work on OS X 10.9/iOS 7 and lower?

Android Studio how to run gradle sync manually?

Unable to connect to mongodb Error: couldn't connect to server 127.0.0.1:27017 at src/mongo/shell/mongo.js:L112

Sorting multiple keys with Unix sort

How do I create a view controller file after creating a new view controller?

How to use HTTP GET in PowerShell?

How can I convert a timestamp from yyyy-MM-ddThh:mm:ss:SSSZ format to MM/dd/yyyy hh:mm:ss.SSS format? From ISO8601 to UTC

Use IntelliJ to generate class diagram

How to initialize a private static const map in C++?

ng-model for `<input type="file"/>` (with directive DEMO)

How to get current memory usage in android?

Create directory if it does not exist

Regular expressions inside SQL Server

Generate an integer sequence in MySQL

SSIS Connection Manager Not Storing SQL Password

Why is HttpClient BaseAddress not working?

EditText non editable

How to use jQuery to select a dropdown option?

How to submit a form on enter when the textarea has focus?

How to output git log with the first line only?

How to pass a vector to a function?

Get time difference between two dates in seconds

Pass Method as Parameter using C#